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THE 


SCIENTIFIC PROCEEDINGS 


OF THE 


ROYAL DUBLIN SOCIETY. 


defy Series. 


VOLUME V. 


DUBLIN: 
PUBLISHED BY THE ROYAL DUBLIN SOCIETY. 
-RINTED AT THE UNIVERSITY PRESS, BY PONSONBY & WELDRICK. 
1886-1887. 


= 


Tux Society desires it to be understood that they are not answer- 
able for any opinion, representation of facts, or train of reasoning, that 
may appear in this Volume of their Proceedings. The Authors of the 


several Memoirs are alone responsible for their contents. 


SOb,4T ly 


TO VOLUME FIVE, 


WITH REFERENCES TO THE SEVERAL ARTICLES CONTRIBUTED 
BY EACH. 


Barzy, Wituum H., F.L.S. PAGE. 


On a New Species of Pentremite, from Carboniferous Lime- 
stone, Co. Dublin; and Remarks upon Codaster trilobatus 
(M‘Coy), from Carboniferous Limestone, Co. Kilkenny 
(Plates), ees, en. Sse : : : é Seow 


Batu, V., M.A., F.R.S. 


Zine and Zine Ores, their Mode of Occurrence, Metallurgy, 
and History in India; with a Glossary of Oriental and 
other Titles used for Zine, its Ores and Alloys, F 6 BMA 


_ On the Existing Records as to the Discovery of a Diamond 
in Ireland in the year 1816, . ; ‘ s : > Bee 


BaRRETT, W. F., M.R.I1.A. 


On a New Form of Calorimter, . GaSe cal oh eld (ELS 
' On the Double Quadriform Lighthouse sais , : ae 7A 
On the Physical Properties of Manganese Steel, . ; . 3860 


Drxon, G. Y., M.A. 
Notes on Two Irish Specimens of EHdwardsta timida (Quatre- 
“fages) (Plate VI.),.-  . . Sete : : . 100 
Dixon, 8. M. 
On Twisted Copper Wire, . 5 : , : : . 646 


rh List of Contributors. 


Firz Geratp, Guo. Fras., M.A., F.T.C.D., F.RB.S. 


On the Limits to the Velocity of Motion of the Working 
Parts of Engines, . : : : : ; : 


On the Temperature at various Depths in ae Derg after 
Sunny Weather, . ; : : } a a 
Gruss, Sir Howarp, F.R.S. 


Notes on some Improvements in Equatorial Telescope 
Mountings, 


Note on a Graphical Method of or Certain meee 
Problems, : ‘ & i . 
Happon, Aurrep C., M.A. 
Note on Halcampa chrysanthellum (Peach), . 


Suggestion respecting the Epiblastic oe of the Segmental 
Duct (Plate X.), . : : : < 


Note on the Arrangement of the Miczonteriag i in the Parasitic 
Larva of Halcampa chrysanthellum (Peach) (Plate XI.) 
Hartiey, W. N., F.B.S. 
Note on Lackmoid and Litmin, . 
The Black Marble of Kilkenny, . 
Analysis of the Beryls of Glencullen, Co. Wicklow, 


Haveuton, Rev. Dr., F.R.S., S.F.1.C.D. 
On the Liassic Fossils of M‘Clintock’s Expedition, 


Hutt, Epwarp, LL.D., F.B.S. 


On the Occurrence of an Outlying Mass of Lower Old Red 
Sandstone and Conglomerate in the Promontory of Fanad, 
Co. Donegal, . 


On the different Varieties of Irish Paving-setts, . 


On the Effect of Continental Land in Altering the Level of 
the Ocean, 


PAGE 
160 


169 


107 


40 
94 


649 


List of Contributors. 


JoLy. de. BE 


On a Method of Determining the Specific Gravity of Small 
Quantities of Dense or Porous Bodies, 


Notes on the Minerals of the Dublin and Wicklow Granite. 
I.—The Beryl and Iolite of Glencullen coe Il., IIL., 
and IV.), : : 


On the Permanency of fleece and a ca Con- 
nexion therewith with Oldhamia radiata and O. antiqua, . 


On the Occurrence of Harmotome at Glendalough, Co. 
Wicklow, 


On a Hydrostatic Balance Plate VII.), 


On a Peculiarity in the Nature of the Impressions of 
Oldhamia antiqua and O. radiata, 


The Phenomena of Skating and Professor J. Thomson’s 
Thermodynamic Relation, 


Kinanan, G. Henry, M.B.I.A. 
A Table of the Irish Lower Paleozoic Rocks, with their 
Probable English Equivalents, : ; ‘ : 
On Irish Metal Mining, 
On Irish Marbles and Limestones, 


On Irish Marbles and Limestones. Supplemental, 


The Lisbellaw Conglomerate, Co. Fermanagh, and Chesil © 


Bank, Dorsetshire (Plate XII.), 


Arenaceous Rocks of Ireland :—Sands, Sandstones, Grits, 
Conglomerates, Quartz-rocks, and Quartzytes, 

Deal Timber in the Lake Basins and Peat ree of North- 
east Donegal, . 


Gravel Terraces; Valleys of the ce Sua, and Roste, 
Counties of Tyrone and Donegal, ‘ 5 : 


Lavis, H. J. Jonnston, M.D. 


The Relationship of the Structure of Rocks to the Conditions 
of their Formation, ‘ ; : ‘ d : 


PAGE 


156 


165 
347 


445 


453 


34 
200 
372 
489 


504 


507 


629 


636 


118 


vi List of Contributors. 


Mutten, Bensamin H., B.A. PAGE 

On a Cloge Almanack in the Science and Art Museum, 
Dublin (Plate V.), . 79 

O’Renuy, J. P., C.H. 

On the Gaseous Products of the Krakatoa Eruption, and of 
those of Great Eruptions in general, , 17 

On the Antipodal Relations of the New Zealand ashe 
District of June, 1886, with that of Andalucia of Decem- 
ber, 1884 (Plate 1X.), 455 

Preston, Tuomas, B.A. 
On the Inversion of Centrobaric Bodies, 639 
Rampaut, A. A. 

On a Mechanical Method of Converting Hour-angle and 
Declination into Altitude and Azimuth, and of Solving 
‘other Problems in Spherical Trigonometry, 642 

Reynoups, J. Kuerson, M.D., F.R.S. 

Note on a Brilliant Meteor seen at Strasburgh on the 15th 

of August, 1886, .. 889 
Sonzas, W. J., HELD), D.Sc. 

Note on the Artificial Deposition of Crystals of Calcite on 
Spicules of a Calci-sponge, ; : : 73 

On a Classification of the Sponges, 112 

Preliminary Account of the Tetractinellid Sponges Dredged 
‘by H.M.S. “Challenger,” 1872-76. Part 1—The Choris- 
tida, : § ‘ ‘ : . Be dys 

On the ‘‘Cocal Processes” of the Shells of Brachiopods 
Interpreted as Sense-organs, . 5 5 ; ols 

On a Specimen of Slate from Bray Head, traversed a the 
Structure known as Oldhamia radiata, F 355 

Supplementary Remarks on Oldhamia (Plate VIII.), 358 

On a Separating arcu for use with Heavy Fluids (Plate 
xe) : 5 é : . 621 

On a Modification of cone rece for Determining 
the Specific Gravity of Solids (Plate XIV.), - 623 


List of Contributors. 
Stoney, Grorce J., M.A., D.Sc., F.B.S. 


Curious Consequences of a well-known Dynamical Theorem, 


Stoney, Greraup, B.A. 


An Experimental Method of Determining Moments of Inertia, 


Trouton, Frep. T., B.A. 


A Thermo-electric Current in Single Conductors, 


Watsn, A. R. 


An Experiment on the Surface Tension of Liquids, 


WERNER, Emin. 


Note on a Specimen of Adulterated Guano, . 


Wynne, A. B. 


Notes on some recent Discoveries of Interest in the Geology 
of the Punjab Salt Range, 


Note on Submerged Peat Mosses and Trees in certain Lakes 
in Connaught, 


o6 
Vil 


PAGE 


448 


000 


171 


484 


345 


85 


499 


DATES OF THE PUBLICATION OF THE SEVERAL PARTS 


OF THIS VOLUME. 


Part 1.—Containing pages 1to 40. (Jan., 1886.) 
3 ee 94 a 41 to 112. (April, 1886.) 
A , 11810176. (July, 1886.) 
4 », 177 to 820. (Oct., 1886.) 
" » 9821 to 446. (Jan., 1887.) 
447 to 498. (April, 1887.) 
Re ,, 499 to 628. (July, 1887.) 
3 », 629 to 656. (Nov., 1887.) 


COE Coe SMe aS 


o 
N 


Haat hoe) 
i MN 


THE 


SCIENTIFIC PROCEEDINGS 


OF THE 


, ROYAL DUBLIN SOCIETY. 


I.—NOTEK ON AHALCAMPA CHRYSANTHELLUM, PEACH. 
By ALFRED C. HADDON, M.A., M.B.I.A., Professor of 
Zoology, Royal College of Science, Dublin. 


[Read, November 18, 1885.] 


T the corresponding meeting of the Society last year I read a 
Paper on ‘‘ A New Species of Halcampa (H. andresii), from 
Malahide,” which was printed in the Procecdings, n.s., vol. iv., 
pp. 396-398, pl. xvt., figs. 1-4. Since that date I have, through 
the kindness of my friends Mr. H. W. Jacob and Mr. G. Y. Dixon, 
seen several specimens of Halcampa from Malahide, and I find 
that every one has some variation in colour or marking. This 
fact has led me to reconsider the characters upon which I based 
the new species just alluded to, and it has resulted in the opinion 
that it would be wiser to withdraw that name, and to regard our 
Dublin specimens as the first known Irish examples of H. chry- 
 santhellum, Peach. 

While regretting the fact of introducing what I may term a 
stillborn synonym (especially when coupled with the name of my 
friend Professor A. Andres), the figures at all events convey a 
much better idea of the species than the very unsatisfactory ones 
on plate vii. in Gogse’s Monograph, and so far the Paper is not 
altogether valueless. 


SCIEN. PROC., R,D.S.—VOL. V. PT. I: 


B 


2 Scientific Proceedings, Royal Dublin Society. 


In order to substantiate my present view, I propose to give a 
brief account of all the descriptions we have of H. chrysanthellum, 
together with a short description of the specimens which have 
passed under my notice. This will, I hope, have the further 
effect of putting other naturalists on their guard, and of tending 
to give some idea as to the specific characters of this form. 


The following is the bibliography of this species :— 


Actinia chrysanthellum, . Peach, 1847, in Johnston’s Brit. Zooph., 
2nd ed., p. 220, pl. xxxvu., figs. 


10-15. * 
Edwardsia duodecimcirrata, Sars, 1851, Nyt. Mag. for Naturvid., vi., 
p. 142. 


Cocks, 1851, Rep. R. Cornwall Polytech. 
S0C., 1X., p. 6, Pl. 1, tesa Ose 
Landsborough, 1852, Pop. Hist. of Brit. 


Zoophytes. 
Peachia (?)\; -.. . & =) Gossey) U8bo, | Trans. Linn. econ mmxeate 
Tee Parfit 
n m . Gosse, 1855, Manual, Marine Zool., i., 
Deol. 


Milne Edwards, 1857, Hist. Nat. des Coral- 
liaires, p. 288. 


Haleampa, . . . . . Gogse, 1858, Ann. Mag. Nat. Hist. (8), i» 
p. 418. 

Edwardsia duodecimcirrata, Danielssen, 1859, Nyt. Mag. for Naturvid., 
X1., p. 45. 


Liitken, 1860, Naturhist. Foren. Vidensk. 
Meddel., p. 196. 


oe - . Gosse, 1860, Actinologia Britannica, p. 247, 
pl. vu., figs. 9, 10, and woodcut. 
fe ; . Hincks, 1861, Ann. Mag. Nat. Hist (8), 


Viil., p. 363. 

Xanthiopus bilateralis,. . Keferstein, 1863, Zeitschrift fur wiss. Zool., 
xil., p. 34, pl. 11., fig. 22. 

Xanthiopus vittatus, . . Keferstein, 1863, loc. cit., p. 34, pl. m., 
figs. 15, 16. 

Edwardsia duodecimeirrata, Meyer and Mobius, 1868, Archiv. fiir Na- 
turgesch, p. 70, pl. m1. figs. A-D. 


Happon—Wote on Halcampa chrysanthellum, Peach. 3 


Halcampa chrysanthellum, Dana, 1872, Corals and Coral Islands, 
p- 25, fig. 38. 

Grube, 1878, Mittheil. iiber St. Malo und 
Roscoff u. d. dortige Meeres-besonders ; 
die Annelidenfauna, p. 88. 

Fischer, 1875, Nouv. Arch. Mus., x., 
p. 204. 

Andres, 1884, Fauna und Flora d. Golfes 
v. Neapel., ix., p. 101. 


Halcampa kefersteem, . . Andres, 1884, zbid., p. 102. 
Halcampa farinacea, . . Andres, 1884, in part (not of Verrill), 
ibid., p. 102. 


Halcampa andresii, . . Haddon, 1885, Proc. R. Dub. Soc. (n. 8.), 
iv., p. 396, pl. xv1., figs. 1-4. 

Halcampa chrysanthellum, Pennington, 1885, British Zoophytes, 
Dee livia 


Johnston’s diagnosis of the species is as follows :—“ Body cylin- 
drical, smooth, striped; tentacula twelve, uniserial, sub-marginal, 
annulated with brown.’ He quotes the following from Peach’s 
ms. :-——“‘ This Actinia I find under stones buried in sand in Fowey 
Harbour between the tide-marks. Body pale, nearly white, with 
six broad stripes, and three narrower ones between each of the two 
broader ones, the centre one of the three the broadest—all running 
the whole length of the body, but are nearly lost before reaching 
the lower end: these stripes are again divided -by transverse nar- 
row ones. ‘The tentacula are invariably twelve; the mouth is in 
the centre, and surrounded by brown flower-like markings. It 
does not attach itself, but les buried in sand, with its head 
just above.” . 

“‘The species readily assumes various shapes, as shown in the 
figures of it. It is quick in its motions, and buries itself in the 
sand when disturbed.” 

Cocks merely quotes an abbreviation from Peach’s diagnosis, 
and adds:—“In pools with sandy bottoms, Gwyllyn-vase, Pen- 
nance, &c.; not uncommon.” His figures are very unsatisfactory ; 
in both only eleven tentacles are represented, although the text says 
“tentacula twelve”; in fig. 20 they are banded, but not so in 
fig. 21; in both the disc is quite plain. In fig. 20 the animal is 

B2 


4 Scientific Proceedings, Royal Dublin Society. 


drawn in a vertical position, its base being expanded and attached 
to a stone; although it can stand upright in the water when in con- 
tact with a hard substance, it does so owing to the tenacity of the 
suckers of its physa, and not, so far as | am aware, in consequence 
of the latter forming a basal disc. Fig. 21 merely gives a fore- 
shortened view of the disc and tentacles, and below it is an indis- 
tinct figure which is not referred to, and which apparently is 
intended to represent the aspect of the tentacles, &c., when buried 
in the sand. I mention this Paper and figures in detail to obviate 
the necessity of future reference, as the Annual Report in which it 
occurs is not easily accessible. 

Gosse, in his Paper in the Transactions of the Linnean Society, 
1855, adds no new facts; he speaks of its ‘ sensitiveness to alarm, 
and the spring-like rapidity of its motions.” He considered that 
there was a posterior aperture. Size, “very minute.” In his 
Marine Zoology, 1855, and in his Synopsis of the British Actin, 
1858, Gosse merely alludes to the species; in the latter, he cor- 
rectly constituted it the type of a new genus, to which he gave 
the name Halcampa. 

In his Monograph, 1860, Gosse mentions that he had upwards 
of a dozen specimens sent him, in 1858, from Fowey. As these 
came from Peach’s locality, their identity with the discover’s spe- 
cies is beyond doubt, but the marking seems to be quite different 
from the original figure (/.c. pl. xxxvir., fig. 13). The latter, how- 
ever, 1s very unsatisfactory. Gosse’s description of the markings of 
the disc, also, does not particularly well agree with the woodcut he 
gives. The description is as follows :— 

Column.—* Drab or dirty white; septa as white longitudinal 
lines; the swollen bladder-like extremity translucent. 

' Disk.—“ Marked with. a pretty star-like pattern, consisting of 
a pale-blue area inclosed in a pale line, and surrounded by twelve 
triangular rays of a dark-brown hue; each triangle surmounted by 
a pale, W-like figure, which incloses a dark-brown area, according 
to the accompanying pattern. 

Tentacles.—“ Pellucid brown, the front crossed by six semi-rings 
of opaque white, of which the second, the fourth, and the fifth 
(counting from the foot upward) are angular, the second pointing 
downward, the fourth and fifth upward. ... The pellucid inter- 
spaces are tinged with brown, deepest on the first, second, and 


Happon—Wote on Halcampa chrysanthellum, Peach. 5 


fourth ; and the first white ring surrounding the foot is sometimes 
tinged with sulphur-yellow.” 

The description of the specimens dredged by Sars, in twenty 
fathoms, at Ure, Lofoden Island, and also at Bergen, agrees so 
closely with some of the Malahide forms that there can be little 
doubt as to their identity. He describes the body as cylindrical, 
white; hyaline, with a brown epidermis; tentacles twelve, white; 
hyaline, with two brown rings; twelve brown spots round the 
mouth. The shape of tentacles and other points are identical in 
the two forms. The brown “epidermis” probably refers to the 
slimy sheath being beset with sand or other foreign particles. 

The careful account of Meyer and Mobius leaves no doubt con- 
cerning the identity of their specimens with Peach’s. They state 
that the body is smooth, flesh-coloured, with pale longitudinal 
lines; it generally covers itself with a tube of slime and sand 
erains. The tentacles are quite colourless, with two or three red- 
dish-brown transverse bands, and similar longitudinal stripes at 
their bases; there are brown spots on the disc, each corresponding 
with the tentacle. 

The authors refer to the extreme transparency of the dilated 

body, and to the presence of a pair of fine lines in the alternate 
broad red bands of the body, referring, of course, to the small 
secondary mesenteries (fig. 4, p. 12), and of which they give (pl. m1., 
fig. C) a characteristic drawing. ‘They found eight to eleven ten- 
tacles in their forms—length, 20-25 mm.; diameter, 2-3 mm. 
In mud, Bay of Kiel, 6-9 fathoms. They further identify with 
this species the two specimens found by Dr. Litken, at Helleback 
in the Sound; but Andres (/. c., p. 96), considers this a true 
Kdwardsia, which he names F. Jithend. 

Dr. Andres correctly placed Sars’ species in the genus Hal- 
campa; but he believed that it was identical, save for characters 
‘“‘of the smallest importance,” with Halcampa farinacea, Verrill, 
and, “rather than preserve a record of the two species,” he unites 
them into one. Whether Verrill’s species is identical with any 
Huropean form is very doubtful, and the evidence would seem to 
point the other way: for the present, at all events, his name must 
stand. 

The great range of variation of H. chrysanthellum suggests a 
critical examination of the two species which Keferstein described 


6 Scientific Proceedings, Royal Dublin Society. 


from St. Vaast la Hogue (Manche, N. France), and for which he 
constituted the new genus Xanthiopus; his definition of this genus 
agrees so exactly with that of Halcampa, as defined by Gosse, that 
there is no doubt they are synonymous, and the latter has the pre- 
cedence. The two species are yellowish in colour, and were found 
in the small chinks in the granitic rocks at extreme low water. 

Haleampa (Xanthiopus) bilateralis.—The tentacles corresponding 
to the ends of the mouth are differently formed and without trans- 
verse bands, as in the other ten, and which bear two yellow trans- 
verse bands. All the tentacles are continued over the oral disc as 
triangular swellings to the opening of the mouth. About 40 mm. 
long. 

H. (X.) vittatus.—All the twelve tentacles are similarly formed, 
with four yellow transverse bands; they do not run over the oral 
dise to the mouth. Mouth in the middle of asmall, conical, raised, 
yellow ring. About 20 mm. long. 

These two forms are undoubtedly the same species. Andres, 
also, is of the same opinion; but he, contrary to the British rules 
of Zoological nomenclature, re-names the species as H. kefersteini, 
consisting of “var. a vittata; tentacles equal; small size; and var. 
(3. bilateralis ; Gonidial tentacles different from others by lacking 
the annulations; larger size.” 

The pale colour and different appearance of the gonidial 
tentacles of the first species is not unfrequently met with in 
many of our British sea-anemones (e.g. Tealia crassicornis, Mull., 
Actinoloba dianthus, Ellis, and Heliactis bellis, Hill. and Sol.). The 
only other distinctions between the two species are different num- 
ber of yellow bands on the tentacles, and the presence or absence 
of distinct radii on the oral dise—characters too slight to alone 
constitute specific distinctness. The conclusion at which we must 
arrive at:is, that these two forms are merely varieties of H. chry- 
santhellum. 

Dr. Ed. Grube found H. chrysantellum (sic) at Roscoff, buried 
in the sand at low water. He states that it only occurs in a single 
zone. “A few steps nearer the sea and one no longer finds it. 
These and the nearly allied Edwardsias are so completely hidden 
in the sand that their presence is not betrayed.” He describes it 
as a perfectly white polyp, of the thickness of a swan’s quill, with 
twelve short tentacles, and a single black point between each. The 


Happon—Wote on Haleampa chrysanthellum, Peach. 7 


lower portion of the body is described as being glandular, in the 
habit of forming a sheath for itself, having a revolving motion, 
and becoming swollen and transparent; he also noticed that its 
posterior end could adhere a little. 

Landsborough, Milne Edwards, Hincks, Dana, Fischer, Andres, 
and Pennington, merely repeat previous descriptions more or less 
fully, but add nothing new thereto, so it is unnecessary to refer at 
length to them. . 

Previous observers have accurately described the general ap- 
pearance and habits of this interesting little anemone. I need 
add only a few supplementary notes.’ 

In my former Paper I have figured what may be regarded as 
the general form of the animal when about half extended; but, as 
all observers have noted, the shape may be very varied. The 
physa is usually in a state of more or less distension ; occasionally 
it assumes a very thin, rod-like appearance. (The physa is in this 
state when boring into the sand: compare the similar appearance 
of Peachia hastata, Gosse—Haddon and Dixon—Proceedings of the 
Royal Dublin Society (n. s.), vol. iv., pl. xvitt., fig. 7.) I have been 
unable to see a terminal posterior orifice, but there is a small per- 
foration in each intermesenterial chamber close to its posterior ter- 


1 My friend Mr. G. Y. Dixon has kindly allowed me to copy the following from his 
aquarium notes :— 

““ November 5, 1885.—Only one Halcampa survives [from September 26]. It, how- 
ever, is in splendid health, and has grown considerably, being, when fully expanded, 
2 inches long; scapus, $ of an inch in diameter; capitulum, 4 inch. When fully dis- 
tended it is quite transparent, and its oesophagus can be distinguished quite plainly 
running the whole length of the capitulum as a narrow, straight, pale-orange tube, 
which terminates just at the constriction which usually marks the limit between the 
scapus and capitulum. ‘The twelve mesenteries are very conspicuous in the scapus, 
their inner free edges being orange, and,shining through the pellucid body wall. With 
an inch objective you can distinctly see round glands (?) imbedded in the convoluted and 
swollen edges. The mesenteries are arched above where they run in to join the cso- 
phagus, and are gradually sloped away as they come down towards the constriction 
which usually marks off the physa from the scapus. The clearness and transparency of 
the whole animal, but above all of the scapus, almost surpasses belief. I cannot find 
any marks on the physa like those in Peachia hastata.’’ [This, of course, refers to rows 
of pores alluded to in our joint Paper.—A. C. H.] 

“Four pairs of mesenteries are longer than the rest, and are more convoluted on 
their edges and more orange in colour; between each of these pairs is a mesentery 
which does not run down so near the physa; its edge is not so swollen or convoluted, 
and is more of a straw-colour than orange. Is it possible that this points to an affinity 


8 Scientific Proceedings, Royal Dublin Society. 


mination. Similar pores, which by the way are very difficult to 
observe, were found in Halcampa clavus, Quoy and Gaim, by R. 
Hertwig, and I have also seen them in the so-called Halcampa 
fulton, St. Wright. These perforations enable the physa to be 
suddenly emptied of its contained water. They exist in large 
numbers in Peachia hastata, both Mr. Dixon and myself being 
now satisfied that such is the true explanation of the appearances 
we described (/.c., p. 403). The whole body is continually under- 
going slow waves of alternate contraction and expansion. As 
Gosse states, the body is capable of great extension (“ extending 
to ten times its diameter or more). . . Specimens reach to an inch 
and three-quarters in length, and one-eighth of an inch in average 
diameter; the extremity is frequently inflated to one-fourth.” 

My longest specimen was about 50 mm. (2 inches) in length, 
and about 3°5 mm. (2; of an inch) in diameter at the middle. 
Other specimens measured about 31 mm., 38 mm., 44 mm., &e. 
(13 in., 13 in., 1} in.) in length. 

In nearly every case the tentacles, although monocyclic and 
perfectly uniform in size and shape, appeared to consist of two 
series. Those of the first series, which for the sake of conveni- 
ence. I term the primaries, are usually carried more or less arched 
forwards and inwards, and are also almost invariably more pro- 


with the octoradial Edwardsie?’’ [In connexion with the last paragraph I would 
quote the following from Dr. R. Hertwig’s Report on the Actiniaria, Challenger Re- 
ports, Zoology, vi., 1885, p. 95.]:— 

‘‘The constitution of the septa in Haleampa cavus [Quoy et Gaim] shows further 
peculiarities worthy of notice, which seem to me to indicate its relation to the Edwardsiz. 
As I was preparing a series of sections through one-half of the physa of the larger spe- 
cimen, it struck me that three septa [mesenteries] (including the pair of directive septa 
[mesenteries]) were not so strong as the other septa, inasmuch as their longitudinal 
muscular cords became sooner indistinct (pl. x111., fig. 7.) In the second smaller Hal- 
campa, in which I was able to make sections through the entire body, four septa were 
somewhat smaller than the eight others; and, finally, Strethill Wright has described a 
parasitic Halcampa living on Meduse (Halcampa fultoni), in which he can distinguish 
four stronger and eight weaker septa (Ann. and Mag. Nat. Hist., ser. 111., vol. viii., 
p. 188, 1861). All this shows that an unequal development of the septa, and, consequently, 
a difference in their morphological value, is not unusual in Haleampa. If we assume 
that the eight stronger septa are homologous with the septa of Edwardsia, whilst the 
four other septa are new formations, then the genus Halcampa would present us with 
transition forms between the Edwardsie and the Hexactinie.’’ [As the present com- 
munication is merely a critical note on the identity of the species in question, I do not 
intend on this occasion to follow up the line of thought here suggested.—A. C. H.] 


‘ Happon—WVote on Halcampa chrysanthellum, Peach. 9 


minently marked and coloured. As they are prolongations of 
those mesenterial chambers which have no secondary mesenteries 
(see fig. 4, p. 12), and as one of them is situated at each end of the 
slit-like mouth, they therefore correspond to the primary tentacles 
of other Actiniz. The tentacles of the second series (secondaries) 
usually bend outwards and downwards, being slightly recurved at 
the tip. Their colouration and pattern is often paler and more or 
less obscure. 

The colour of the scapus is usually whitish, sometimes tinted 
with buff, and rarely opaque orange. As previously noted, when 
mature, the ovaries shine through the translucent body with a 
creamy orange colour. 

The insertions of the mesenteries appear externally as longitu- 
dinal white lines: between each alternate pair of mesenteries there 
is a pair of small mesenteries, which appear on the outer surface as 
two thin white lines. ‘This explains Peach’s account of the stripes 
of the column, the “stripes” being the darker, 7.e. translucent, areas 
between the mesenteries. The transverse stripes noticed by Peach 
are merely external corrugations due to the contractibility of the 
body. (See fig. 2, p.12.) The capitulum is subject to considerable 
variation in ornamentation: usually it is buff, sometimes with a 
brown band. The white or pale-yellow bracket-marks alluded to 
in my former Paper appear to be very constant in their appearance. 

It is, however, in the disc and tentacles that the greatest amount 
of variation occurs. I have therefore briefly described a number 
of variations to prove how careful one should be in laying any stress 
upon colour or markings, in dealing at all events with this species. 

1. Disc opaque white. Tentacles very pale buff, with five paler 
bands ; the lowermost two are waved or [-shaped. White bracket- 
’ marks externally at base of tentacles. 

2. Dise pale lemon-yellow. Tentacles very pale buff, with five 
white bands, and some indistinct brown bands, which are much 
more distinct on the six primaries. A brown band round the 
eapitulum, and pale bracket-marks. 

3. Dise rusty colour, with distinct paler radiating lines (mesen- 
teries), forming twelve dark-coloured wedges. ‘T'entacles of same 
rusty colour, with five pale bands, the four upper of which are 
straight, and the lowermost is \/-shaped. The inverted triangular 


10 Scientific Proceedings, Royal Dublin Society. 


area left between this and the lowest straight line is dark in 
colour. : A. dark ring all round the base of the tentacles. 

4, Disc pale, with a lenticular dark-brown mark in each radius, 
and external to it at the base of each tentacle a brown line. The 
six primary tentacles have the lowest half ring, dark in colour, and 
V-shaped, with a dark spot between the two limbs of the \/; the 
other lines pale. ‘The six secondary tentacles have pale indistinct 
markings, the lowermost of which is M-shaped. White external 
brackets. 

5. Disc pale-buff round mouth, separated from the pale-yellow 
peripheral portion by a chain of dark-brown lenticular marks, 
which practically form a ring. At the base of each tentacle is a 
transverse dark-brown line; base of tentacle white ; remainder pale- 
buff, the two colours being separated by a dark [yj-mark; there are 
also one or two indistinct pale-brown markings. At the base of 
each tentacle externally there is a lateral dark line, which shghtly 
converges towards its fellow. 

6. Disc pale, with alternate dark (primary radii) and light 
(secondary radii) lenticular marks. The primary tentacles are very 
dark; there is a basal [f-mark, with a dark triangular mark a 
little way above. ‘The external bracket-marks are prominent, and 
below each is a pair of dark spots. 

7. Dise pale-orange, a white spot opposite each tentacle. Ten- 
tacles with five pale rings, the lowermost [f-shaped. There is a 
small pale basal mark. The external bracket-marks are very 
plain. 

8. Dise pale-buff; an indistinct pale \V-mark in the centre of 
each radius. Tentacles with five pale rings, of which the lower- 
most is M-shaped. 

One or two other varieties were seen, but a sufficiently careful 
note of the colour and pattern was not made. 

The variations of the disc and tentacles are so many, that at 
first sight it seems almost hopeless to give any character which 
would be of service for specific determination. I have, however, 
ventured to give a drawing (fig. 3, p. 12) of what I take to be the 
general pattern of the disc and tentacles. 

The following diagnosis will, I hope, be found to be essentially 
correct :— : 


Happon—WNote on Halcampa chrysanthellum, Peach. 11 


Haleampa, Gosse. 


Body elongated, cylindrical, divided into a capitulum, scapus, 
and physa; the mesenteries are more or less apparent throughout 
their whole length ; except when fully extended, the body is corru- 
gated; physa with minute suckers. ‘Tentacles twelve, monocyclic, 
marginal, cylindro-conical. Disc plain; mouth linear, slightly pro- 
minent. British species— 


Hi. chrysanthellum, Peach. 


Form.—Body vermiform, extending to about ten times its dia- 
meter; smooth, or only secreting a mucous tube. Capitulum and 
tentacles completely retractile; physa large, non-retractile. 

Colour.—Column whitish, occasionally slightly yellowish or buff, 
rarely orange; capitulum often more or less buff-coloured; a pair 
of pale bracket-marks () usually present below the angles between 
the tentacles. The orange-coloured ovaries, when ripe, shine through 
the walls of the scapus, giving it a creamy-orange colour. The in- 
sertions of the mesenteries appear throughout the whole length of 
the body as white lines, and the suckers appear as white dots on 
the otherwise transparent physa. 

Dise white, pale-yellow, or pale-buff; may be quite plain, or 
ornamented with variable brown markings. 

Tentacles pale-buff, with five or six light or dark bars on their 
internal aspect, of which the basal is usually straight—the second 
M-shaped, the third V-shaped, the three (or four) upper being 
usually more or less straight. Hxternally, at the base, dark lines 
or spots are generally present. | 

Size.—30-50 mm. (14 to 2 in.) long, when fully extended. 
About 3°5 mm. (23; in.) in diameter. 

Habitat.—In Send or crevices of rock at low water, and down 
to 20 fathoms: S.W. England, EH. Ireland, N. Fr ance, Norway, 
and Denmark. 

This is the only recorded British species; but last summer I 
dredged a well-marked second species at a depth of forty fathoms 
off the mouth of Kenmare river, a description of which will in due 
time be laid before the Royal Irish Academy. ~ | 

Halcampa fultom, St. Wright (Proc. Phys. Soc., Edinb., ii., 
p- 91, 1859), is, undoubtedly, an immature form. I obtained 
specimens of it which were parasitic on some Hydromeduse 


12 Scientific Proceedings, Royal Dublin Society. 


(“ Thaumantias”’), in June, 1885, at Kingstown, county Dublin. 
I have observed several phases of its development, but could not 
obtain a sufficiently complete series to definitely state of what 
Actinian it is the larval form. My opinion, however, is, that 
it will prove to be the young of H. chrysanthellum. 

The above communication is but a further contribution to the 
systematic knowledge of our British Actinie. I am fully aware of 
the morphological interest connected with the free Actiniz, and 
though I have made some anatomical investigations on this form, 
I refrain from publishing them till I have examined a sufficient 
number of other sea-anemones to render a description and com- 
parison profitable. 


Fig. 1.—Side view of a fully extended Halcampa chrysanthellum, magni- 
fied about 2 diameters. 

2.—Generalized diagram of markings of oral disc and tentacles. 

3.—Side view of capitulum and tentacles. 

4.—Transverse section through the lower portion of the capitulum. 
The following points should be noted :—The arrangement 
of the muscular bands on the twelve mesenteries; the ex- 
istence of a pair of very small secondary mesenteries in 
the alternate intermesenterial chambers; the existence of 
a pair of deep sagittal cesophageal grooves, which are pro- 
vided with long cilia, and of five obscure furrows on each 
side of the ciliated cesophagus. 


[Figs. 2,8, and 4 are placed in the same relative position, and are not 
drawn to scale. |] 


[ 18 ] 


IT.—ON A NEW FORM OF CALORIMETER. By W. F. 
BARRETT, Professor of Physics in the Royal College of 
Science, Dublin. 


[ Read, June 16, 1885.] 


AN accurate mode of determining the specific heat of bodies, with- 
out the serious corrections that have to be introduced in the ordi- 
nary method of mixtures, is much needed. Mr. Joly has lately 
devised and described before the Royal Dublin Society a novel 
and ingenious method depending on the amount of steam con- 
densed by the body; but I have not found this method answer so 
well for determining specific heats as for latent heats of vaporiza- 
tion; in the latter case it leaves little to be desired.! 

The method devised by Professor Bunsen is well known. A con- 
venient modification of Bunsen’s calorimeter was made some time 
ago by Professor Emerson Reynolds, wherein the calorimeter takes 
the form of an alcohol thermometer with a large bulb, and having an 
arbitrary scale, the value of which is determined separately. The 
instrument I now beg to submit to the Society resembles the fore- 
going in so far as the cup for holding the body under experiment 
forms a portion of the thermometer, which, however is mercurial, 
and has a very open scale. The instrument is shown in the wood- 
cut on next page, and its present form is mainly due to the valu- 
able suggestions made, in the course of working with it, by Mr. 
J. M‘Cowan, the Demonstrator of Physics in this College. Asa 
piece of glass-blowing it is, I believe, unrivalled, and is a testimony 
to the skill of Mr. Hicks of Hatton Garden, London, who under- 
took to make it for me, and who informs me that the cup is blown 
out of a single piece of glass tubing.’ 

The cup, A, has a capacity of about 4 cubic centimetres; it is 
surrounded by a jacket of polished metal,® to prevent any slight loss 


1 { understand Mr. Joly has since improved his apparatus for finding specific 


heats. 
2 Since this Paper was read, Mr. Hicks has made several of these instruments, and 


can now produce them at a moderate cost. 
3 A simpler expedient is to silver the outside of the bulb of the thermometer by 


Liebig’s process. 


14 Scientific Proceedings, Royal Dublin Society. 


of heat by radiation, and is provided with a little silvered cover, G. 
The stem, B, is supported horizontally, and is graduated from — 5° 
to 70° or 80° Centigrade, and reads easily to tenths of a degree 
Centigrade. Supported immediately over the cup is a small burette, 
C, the level of the liquid in which can be very accurately read, 


owing to the fact that only a longitudinal, narrow chink of clear 
glass is left in the centre, the sides being of opaque enamel. The 
mouth of the little burette is funnel-shaped, and its neck can be 
closed by the thermometer, D, it carries, the end of the thermometer 
bulb being ground to the neck or made water-tight by a small 
rubber ring. This thermometer is short, but has an open scale, 
and is graduated from about 30° to 100° C. Into the burette is 
placed the warm water or other liquid: by loosening the thermo- 
meter the liquid is allowed to run into the calorimeter, A, below ; 
the mean temperature of the issuing liquid is thus accurately deter- 
mined as it flows past the bulb. When the cup, A, is nearly full 
the burette is closed by pushing down the thermometer, D, and the 
cover, G, quickly placed over A.: the highest reading on the stem, B 
is now taken. ‘The volume of the liquid used is then read from the 
burette, and the operation is complete. But as the volume of the 
liquid has been measured, its weight must be found by taking its 
specific gravity for the temperature at which it was used. 

To obviate this inconvenience, the weight of the liquid can be 
found directly in the arrangement shown in the figure. 

Here the thermometer is turned into a balance, the stem being 


Barretr—On a New Form of Calorimeter. 15 


supported by knife edges, H, somewhere near its centre of gravity. 
From the end of the stem a pan, I’, depends, and beyond this a 
pointer, fixed to the stem, moves over a graduated are. ‘The pan 
is made of the right weight to exactly equipoise the arrangement 
at a given air temperature. The weighing of the liquid in the 
cup, A, is taken at this temperature ; otherwise the varying length 
of the thread of mercury in the stem, B, would derange the balance. 
Except as a thermometer-stopped funnel for the liquid, the burette 
is, of course, not required in this arrangement. 

In making a determination of the specific heat of a liquid with 
this instrument we require no cool liquid in A to mix with the 
warm liquid from C, for the bulb of the thermometer, A, itself 
forms both the containing vessel and the cool material to be 
warmed. All that is necessary is a careful determination, made 
once for all, of the heat capacity of the instrument. This constant 
factor, K, may in fact be found and stamped upon the base of each 
instrument before it leaves the maker’s hands. As the constant is 
determined in precisely the same way that subsequent measure- 
ments are made, it includes, or rather it enables us to evade, all 
corrections, such as those due to the heat capacity of the vessel and 
of the thermometer, and also the loss of heat due to cooling if the 
same range of temperature be employed; and indeed, if otherwise, 
the silvered jacket and cover (which latter is necessary to prevent 
loss from evaporation) render the correction from this source negli- 
gible in ordinary work. 

The constant, A, is found as follows :— 

Let W be the weight of water used, 7 its original temperature 
(viz. that indicated by the thermometer-stopper) ; let ¢ be the ori- 
ginal temperature of the calorimeter (given on the stem, B), and 0 
its highest reading after the water has entered. As the heat lost 
on the one hand is equal to the heat gained on the other, and the 
specific heat of water is unity, 


W (T-0)=K (0-12); 


whence 


When a determination of the specific heat, S, of a liquid has to be 
made, warm the liquid, and pour it into the burette ; note as before 


16 Scientific Proceedings, Royal Dubin Soctety. 


its temperature, 7, as it issues, and afterwards find its weight, W’; 
note the rise of temperature of the calorimeter from ¢ to 0; then 


K @-¢t 


SW T6 


A few minutes suffice to complete the whole determination to 
within a limit of error of one per cent. It will be obvious that 
for ascertaining the specific heat of small quantities of rare liquids 
this form of calorimeter will be found particularly applicable; and 
as the determination of the specific heats of organic liquids can 
thus be readily and accurately made, the instrument may be of 
use to chemists in the investigation of the molecular weights of 
such compounds. 

The instrument is not quite so applicable for the specific heat of 
solids as of liquids; but it may be used for the former when they 
are in powder or in small fragments. In this case the calorimeter 
may first be heated by a known quantity of warm water, and the 
solid at the temperature of the air be dropped in; but this method 
does not yield good results, there being no turning point in the 
temperature. It is better to heat the solid in a small steam or 
water bath, and drop it into a known quantity of water contained 
in the cup of the calorimeter, the heat capacity of which is in- 
creased by this amount, so that its constant now becomes Aj. The 
solid may, of course, be weighed beforehand, so that the simpler 
unbalanced calorimeter can be employed. 


getigan | 


III.—ON THE GASEOUS PRODUCTS OF THE KRAKATOA 
ERUPTION, AND THOSE OF GREAT ERUPTIONS 
IN GENERAL. By J. P. O'REILLY, C.E., President, 
Royal Geological Society of Iveland. 


[Read, November 16th, 1885. ] 


Tue subject of the following Presidential Address is one suffi- 
ciently recent, and, owing to its magnitude, sufficiently important, 
to justify recurrence to it, notwithstanding the many points of 
view from which it has been already treated, and the fulness 
of the reports which have had for their object its description. 

I do not propose to enter into a detailed examination of the 
different phases of this great event, so far as they have been 
recorded, but rather to call attention to certain aspects of the 
phenomena which, from the very first, seemed to me of the very 
highest importance, and as opening up a very wide and interest- 
ing field of inquiry. I allude to the gaseous agents and products 
of the great Hruption as manifested by the quantity and nature of 
the ejected matter, the intensity and range of the explosions, the 
resulting commotions of the atmosphere, and by the singular 
atmospheric phenomena which subsequently became visible all 
round the world, and even still manifest themselves daily. 

In commencing, I will ask leave to refer to the article which, 
shortly after the arrival in Europe of the first accounts of the 
Krakatoa Eruption, appeared in Nature, September 13th, 1883, 
entitled ‘Scientific Aspects of the Java Catastrophe.” With 
reference to this article, I wrote, on the 16th September, the 
following letter to that journal, which appeared in its issue of 
27th September, and therefore, as will be seen, previous to the 
arrival of news relative to the wonderful appearances of the morn- 
ing and evening skies :— 

“Your excellent leading article on this great event omits to 


call attention to a factor which I have long maintained to be of 
SCIEN, PROC. R.D.S.—VOL. Y. PT. I. C 


18 Scientific Proceedings, Royal Dublin Society. 


the greatest interest and importance from the points of view of 
meteorology and geology in general. I allude to the quantity of 
gaseous vapour emitted during the eruption. This must have a 
direct relation to the quantity of matter emitted (whatever its 
form), and also to the height and distance to which the matter 
may be ejected or carried. Now, I hold that such vast quantities 
of gases as must have been liberated on this occasion cannot be 
passed over, or taken as having no action on our atmosphere. 
Whatever the addition made, temperature and air currents are 
influenced by it, either locally, or over great extents of the earth’s 
surface; and if it were possible to take account of the height — 
attained by the gases, their temperature at liberation, and the 
point of the globe whence proceeding, some judgment might be 
attempted of their action. In the present state of meteorology 
we know nothing of these quantities, but it is justifiable to assume 
that the upper currents of the air may be thus profoundly influ- 
enced, and that in certain cases cyclones may thus be generated. 
The present very fine dry weather we are enjoying here, with the 
high and steady barometer, may be a result of the great eruption, 
and it will be worth while to note if any abnormal conditions of 
atmosphere be found to prevail during the coming months.” 

It was not until October 11th that an article appeared, noticing 
‘a green sun in India;”’ therefore, quite subsequent to my letter. 
During the following months the wonderful “ glows” which illu- 
mined the heavens, more particularly after sunset, interested men 
of science of every country, and they have been very generally 
attributed to the presence of vast quantities of dust in the upper 
regions of the atmosphere—this dust being generelly presumed to 
have resulted from the Krakatoa eruption. I may therefore, in 
some degree, claim to have anticipated the appearance of these sky 
glows, in so far as it is accepted that they are due to emissions from 
Krakatoa. I now propose to examine more extendedly the con- 
siderations upon which I based this anticipation. 

It may not be out of place to remark, that in the study of 
natural phenomena we are easily led to attribute a relatively 
greater importance to agents which impress our senses than to 
those more occult in their action, and more particularly which do 
not leave distinct evidence of their influence. Thus, it is only 
quite recently that the ré/e of dust in the formation of rain has 


O’Reitty—On Gaseous Products of Great Eruptions. 19 


been demonstrated by Atkin, and the wondrous organic life of the 
ocean is essentially due to the presence of gases in relatively small 
quantity. Now, no class of agents in nature more easily escape 
attention or baffle investigation than gases, unless they present 
themselves physically or chemically fixed, so as to allow of their 
determination and measurement. The reason of this is obvious. 
Almost all the gases acting at the surface of the earth have densi- 
ties less than that of air; consequently, unless restrained or brought 
into combination, they tend after emission to rise in the air, and 
becoming mixed with the atmosphere, pass to a very great extent 
beyond our observation and our control. 

That the geologist should therefore attribute to them a rather 
subordinate and ill-defined part in the series of phenomena which he 
is called on to study can be understood. Brought, as he is, face to 
face with the rock masses forming the crust of the earth, or with 
the water masses which cover three-fourths of its surface, he natu- 
rally attaches importance to them, rather than to the gases which 
have ever acted, and are acting continually, from the interior or at 
the surface of that crust, but which by their very nature escape his 
attention even while still active agents, and which are so difficult 
of determination and measurement. There is, therefore, some justi- 
fication for my calling attention, in this respect, to those earlier 
phases of the earth’s development, which are usually treated as 
either purely of the domain of astronomy, or are not admitted _ 
as being tangible for the geologist. 

Whatever the hypotheses which may be accepted as to the con- 
ditions of development of the earth, it is generally taken for granted 
that the successive phases of its existence have been similar in 
nature, if not in degree, to those which Science has been led to 
attribute to the other heavenly bodies. Thus we are led to believe 
that it has passed through all the phases observable in one or other 
of these heavenly bodies: from that of a nebula, becoming more 
and more condensed, to that of a sun; and from that of a sun 
through successive stages to the condition of things with which 
geology usually commences, that is, of a globe, having a crust or 
solid exterior, and therefore in a relatively cooled state, and ca- 
pable of allowing the condensation of water on its surface and the 
existence of organic life thereon. Now spectroscopy and observa- 


tion have shown that in the nebul, as in the comets and as in the 
C2 


20 Scientific Proceedings, Royal Dublin Society. 


suns, gases play a very important part, if they be not the only con- 
stituents. For certain of these bodies it has been shown that car- 
bon, and hydrogen, and hydrocarbons, are essential elements, both 
chemically and physically. Are we not, therefore, entitled to as- 
sume that these elements and combinations were abundantly pre- 
sent, and very active agents, in the first stages of the development 
of the earth, and if so, that traces of their influence may still be 
found both in our atmosphere and in the interior of the globe? 
Is it not reasonable to suppose that, in the slow and continuous 
process of contraction, very great masses of gases became retained 
or occulted by the cooling matter, and that these occulted gases 
have been the essential agents in balancing tensions in the con- 
tinually contracting sphere ?—that this continuous contraction led 
to the pressure of masses of these gases until heat was liberated in 
more or less degree, and frequently to the point which brought 
into play chemical affinities; and that thus the whole series of 
phenomena, which have tended and are tending to modify the 
form of the earth’s surface, are intimately bound up with the 
existence and action of gases in the interior and at the surface 
thereof ? : 

Thus, from the very earliest period, we are called upon to re- 
cognize the continuous presence of gases as essential constituents 
of the earth’s mass, and, so far as analogy allows us to judge, as 
most active agents and products of alteration. or the period dur- 
ing which the crust was not yet formed they must have been pre- 
dominating agents; while for the subsequent periods, during which 
the temperature decreased and the crust increased in thickness, their 
intensity of action must have gradually diminished, and their emis- 
sions become more and more spasmodic, or of longer period, until 
conditions were established which we now designate as voleanie, 
that is, when contraction could only take place by reason of the 
sinking of masses of the crust, with accompanying vuleanism and 
earthquake phenomena, such as we witness at the present time, one 
of the most important and constant of which is the emission of 
gases. 

Leaving aside speculation as to the initial constitution, volume, 
and state of the atmosphere, and coming down to the period during 
which the earliest stratified rocks were being formed, we are led to 
imagine for that period a globe greater in diameter than at present, 


O’Remty—On Gaseous Products of Great Eruptions. 21 


having a crust relatively thinner and very differently constituted 
from what now exists; and, since we suppose an ocean of some 
depth and an erosive action, we are led to admit the formation of 
strata under conditions, in some sort, corresponding to those of the 
present state of things. Therefore we should represent to ourselves, 
at that period, an atmosphere having a direct relation, both as re- 
gards quantity and constitution, with the then phase of cooling and 
contraction of the earth. Moreover, we must suppose surfave rocks, 
more or less altered, fissured, and penetrable, in which became re- 
tained chemically and physically a certain amount of gases which 
previously existed as atmosphere; and, finally, we have to picture 
to ourselves an ocean in which, as at present were retained in solu- 
tion gases, also part of the then atmosphere, in quantity and qua- 
lity relative to the temperature and constitution of the then ocean 
mass, and relatively to the prevailing atmospheric pressure. These 
conditions have continued to prevail up to the present time, but in 
degree and in proportions which must have depended, and must 
continue to depend, upon the successive phases of contraction and 
the surface changes of the earth. We can even imagine a last » 
stage when contraction will tend to cease, when, therefore, the 
emission of gases will consequently become less frequent and more 
and more diminished, when the atmosphere as well as the ocean 
will become more and more chemically and physically retained by 
the rocks forming the crust, and when finally our earth will cease 
to have either an atmosphere or an ocean. 

If I have thus ventured so far back into time, it is in order to 
distinctly establish the sequence of relation and the dependency 
which I conceive to have existed at all times between the cooling 
and contracting sphere and the atmosphere. And if we might 
comprehend under that term the sum of the gases existing— 


(a) Free at the surface of the earth ; 


(0) In chemical combination with, and physically retained 
by, the rocks forming the crust; and 


(c) The gases held in solution by the ocean and other waters ; 
then we might consider the sum (a + 4 + ¢) as representing, or as 


being proportional to, the total amount of contraction effected 
since the period of the commencement of formation of the crust, 


22 Scientific Proceedings, Royal Dublin Society. 


The “atmosphere,” properly so called, would be that sum minus 
(b +¢). 

Now one of the most interesting deductions arrived at from 
the examination of the fossil remains of the different geological 
formations is, that our atmosphere has certainly varied both in 
constitution and (most probably) in quantity, and if my assump- 
tion of an intimate relation of the atmosphere with contraction be 
correct, or admissible, there must have been periods or phases of 
marked contraction, and therefore of very active vulcanism and 
accompanying emission of gases, during or about these periods. 
Such geological data as we already possess certainly do point to 
periods of great volcanic activity, manifested by outbursts of lava 
and alterations of the earth’s surface, and corresponding changes 
in the relations of land and ocean. The tertiary period may be 
cited as an example in this respect. 

Turning now from what may, perhaps, be considered as mere 
speculation, to the phenomena of the Krakatoa eruption, it 
will be easily understood that, influenced by the considerations 
already developed, my attention was particularly drawn to- 
wards the ré/e of the gases in this case, and that I was led to 
attribute to them an importance proportional to the magnitude of 
that event. Moreover, that very magnitude seemed to promise 
some phenomena of a nature capable of demonstrating that actual 
additions have thus been made to the atmosphere, and a due 
consideration of the details furnished of the event lead, in my 
opinion, very distinctly to that conclusion. 

From the very careful reports made by their engineers to the 
Dutch Government, as well as from other sources, we have an 
estimate given us of the quantity of ashes emitted, which had 
fallen in such proximity to the locality, as to allow of an approxi- 
mate measurement being attempted. Thus in the report which 
appeared in Nature, vol. xxx. p. 10, the author says: “I found 
that on calculating as accurately as possible the quantity of ejected 
solid substances, they reached 18 cubic kilometres as a safe esti- 
mate. These 18 kilometres represent a weight of more than 
(36 x 10”) kg.” He adds: “the volume of ejected gases was, 
perhaps, hundreds of times greater.” Furthermore, he says: 
“However large the quantity may be, it does not nearly reach 
that which Tamburu produced in 1815, which Junghuhn estimated 


O’Retiy—On Gaseous Products of Great Eruptions. 23 


at 317 cubic kilometres. This computation, however, rests on but 
few data, so that, in my opinion, a quantity of 150 to 200 cubic 
kilometres will come nearer the truth.” 

The quantity thus estimated for the Krakatoa eruption is 
evidently but a part of the total emission of solid matter: what 
proportion this heavier part of the ejected ash bears to the finely- 
comminuted matter, to the presence of which in the atmosphere the 
continuously recurring glows have been attributed, it would be 
impossible to say. How much more must be allowed for the still 
finer matter, which continues suspended at very great altitudes, 
which evidently encircles the earth, and to the presence of which 
is attributed the faintly coppery haze visible round the sun’s 
image ever since the eruption, it is still less possible to estimate ; 
but we can with safety say, that the quantity of vapour and gases 
emitted must have been in some degree proportional to the total 
quantity of ejected matter. We are further justified in assuming 
that the quantity of gas and vapour brought into action was not. 
the minimum strictly necessary to project the totality of this 
solid matter into space; therefore any estimate of the quantities 
of these gases that may be attempted from the data accessible 
ean only be much beneath the truth: indeed this is precisely one 
of those cases where, wanting any term of comparison, the mind 
is simply unable to exaggerate, even were there the will to do 
80. 

Considering, therefore, only the portion of the ashes the 
volume of which has been estimated, and the data as to the 
height to which they attained, it is possible to arrive at a term 
of comparison for the quantity of gases emitted by comparing 
with the results produced by the use of gunpowder or other 
explosives. 

In Berthelot’s remarkable work, Sur Ja force de la Poudre, 
1872, there is a table at p. 190, wherein for each explosive 
examined by him he gives the amount in volume of gases gene- 
rated per kg. of consumed explosive matter, and the temperature 
in ealorics attained. By the aid of this table an approximate 
value for the gases having acted explosively in the case of the 
Krakatoa eruption can be attempted. Let us consider in the 
first place the work done in the case of the discharge of a 100 
ton gun, for which I find in Nature, vol. xxvii. p. 385, the 


24 Scientific Proceedings, Royal Dublin Society. 


following data :—shell = 2000 lbs.; charge = 772lbs. The ex- 
treme range of these guns is about 10 to 12 miles Eng. Now, 
as regards the height to which the ashes were shot up, we have 
the following statement (Nature, vol. xxx. p. 13):—“ The steam 
cloud, according to the measurements taken on board the German 
man-of-war ‘ Elizabeth,’ which left Anjar that morning at nine 
o’clock, must have reached a height of at least 11,000m. During 
the much more violent explosion of Aug. 26th-27th the height, 
if the above report may be relied on, may very well have attained 
15 to 20 km.” (that is from 9°3 Eng. miles to 12°4 Eng. miles) — 
a height about equal to the extreme range of the 100 ton gun in 
question, and without taking into account the increased range 
which should be attained by a projectile shot vertically through 
air of continuously decreasing density. 

Now, admitting that a comparison may be drawn between 
the action of gunpowder in such a cannon, and that of the 
gases or steam in the vent of a volcano, we have merely to 
take the estimate of the quantity of ashes thrown up during 
the Krakatoa eruption, and determine from that the corres- 
ponding charge estimated as gunpowder. According to the re- 
port in question, this quantity of ashes is given as 36 x 10” kg.; 
and as the charge in the case of the 100 ton gun is to the 
projectile as 3472,, we may take as charge in the case of the 
emitted ash, 386 x 10” x =472, = 36 x 10” x 0°386, or approxi- 
mately 386 x 10° x 0-4 = 14:4 x 10” kg. powder. The table 
gives the amount of gases generated per kg. of powder as 
0-225 me. Therefore we have by the explosion of this supposed 
charge of powder 14:4 x 10” x 0°225 me. = 3°24 x 10” me. at the 
pressure 0°76mm. = 3,240,000,000,000 me. | 

To appreciate what this cube means relative to our atmo- 
sphere, we may take this as having a height of about 5 miles, 
or in kilometres, about 8 km. high: dividing, therefore, this 
cube of gases by 8000 m., we have 405,000,000 kms. as the 
surface which would be occupied by a volume of air of that 
cube and 8km. high: this would represent 405 kms., that is 
a surface of about 20km. x 20km. = 12:2 miles x 12:2 miles. 
But the height was really greater than 20km., and has been 
variously estimated at 40 to 50 miles = 64'4km. to 80°5km. The 
quantity of ashes was much greater than that calculated, while 


O’Reitity—On Gaseous Products of Great Eruptions. 25 


the author of the report in question considers “that the volume 
of the ejected gaseous substances was perhaps hundreds of times 
as large”’ as that of the ashes. 

A similar calculation for the Tamburu eruption would give 
us a proportionally greater volume of gases, and in both cases 
merely terms of comparison, since, according to all the authors 
who have had occasion to describe eruptions witnessed by them, 
the quantities of gases and vapours emitted are great beyond all 
comprehension. 

What, however, it is quite necessary to bear in mind, when 
considering this question is that, simultaneously with the Krakatoa 
eruption, gases and vapours were being emitted from a great 
number of vents over the earth’s surface—some mere hot springs, 
from which the quantity of gas issuing, though continuous, is not 
taken account of; others, volcanoes of every degree of activity and 
violence, but only receiving attention when their violence is such 
as to compel observation, but in totality representing a volume of 
vapour and gas immensely greater than any estimate that can be 
attempted, since no term of comparison nor any measurement is 
at our disposal. 

It may naturally be remarked that I include both gases and 
vapour, or steam, together, and that, according to the received 
ideas, the steam was essentially furnished by the sea-water which 
penetrated to the depths where the explosion originated. ‘This is 
not, however, by any means proved. It is to be remembered that 
the amount of water held by the rocks, either chemically or phy- 
sically, is estimated by Delesse to be much more than that of the 
ocean, and this water may sometimes be brought into action. 
But even admitting that all the water ejectcd as steam came 
originally from the sea, the sudden transformation of such a 
quantity of water into steam, and the sudden projection of such 
quantities of it into the air, must have influenced both the sea 
currents and the atmospheric currents, and in this way merit 
‘being taken into consideration. But-in eruptions, along with the 
steam, or independently of it, gases are most certainly projected 
into the air. That such were notably present in the Krakatoa 
eruption is certainly stated by an eye-witness, a captain of one 
of the vessels which happened to be in the neighbourhood, who 
says ‘‘the presence of a powerful marsh gas was also easily 


26 Scientific Proceedings, Royal Dublin Society. 


detected.” — Nature, vol. xxix. p. 29. Moreover, from the obser- 
vations of Fouqué at Santorin, and of St. Claire Deville at 
Vesuvius, we know that hydrogen occurs as one of the emitted 
gases. The following is a Table given by Fouqué, p. 227 of 
his work on Santorin, of the gases collected on the 17th March, 
1877, at that place :— 


I 100 
la a aR ras ee es aN ere Th va ae 
SH Trace 0 
CO? 37:04 | 37°24 | 86°42 | 36°60 0:07 1:49 | 78°44 
C?H* 0°43 0:47 0°86 0°81 0:71 0:42 0°64 
Oars: 0°41 0°51 0:32 1-46 | 21°56 | 18°45 o37 
INGE: 35°02 | 83:66 | 32°97 | 32:04 | 76:04 | 79°64 | 87-55 
a's 27:10 | 28:12 | 29:48 | 30:09 1°62 0:00 0:00 
I.—Taken in fissures. I{.—Taken at the surface of the sea. | 


It must further be remembered, that very frequently, previous to 
eruptions of active volcanoes, gases are emitted from the craters 
and cracks of the voleanoes, and that the emission continues long 
after the cessation of eruptive activity, and may continue for 
centuries when the voleano passes into the state of a hot spring. 
Finally, all over the world, both on land and in the ocean, as has 
been already remarked, this emission is going on continuously 
from the active volcanoes, the hot springs, and simple jets of gas, 
and the daily total of this quantity of gas must be something 
past all calculation. 

It may be objected that were there such continuous additions 
being made to our atmosphere, Science wotld already have ascer- 
tained the fact by comparative barometric observations. But it must 
be remembered that such barometric observations should embrace 


the whole earth’s surface, and have been recorded for a sufficiently 
long time to allow of any effective comparison—that the observa- 


O’Rertuy—On Gaseous Products of Great Eruptions. 20 


tions made at sea must be limited to a relatively small number of 
points or zones—that the polarregions must be perhaps for ever closed 
to observation. Again, the constitution of the upper parts of the 
atmosphere, above 7 miles = 11,000 m. height, are quite unknown to 
us, and will probably ever remain so, since no living being can exist 
at that height. Lastly, that account must be taken of the porosity 
of the surface rocks and soil, and of the ocean, which can absorb 
and retain quantities of gases, variable relatively to temperature 
and pressure. Thus supposing the volume of theatmosphere to be 
actually doubled by volcanic emission at a given moment, it does 
not at all follow that the barometer would show that increase of 
volume in totality and at once, since the pressure on the surface of 
the earth would cause a certain portion to be taken up by the soil 
and rocks, and a certain other part by the water. In this respect, 
indeed, we should perhaps look to the ocean as a far more reliable 
witness to variations of volume in our atmosphere ; and were the 
analyses of ocean water sufficiently numerous, both as regards 
local distribution and depths, and extended over a sufficiently long 
period of time, they would manifest by changes in the quantities 
of contained gases much more accurately, and with much more 
chances of sound comparison, variations in the volume of the 
atmosphere, than would barometric measurement. Here there 
is room to remark that the quantity of gases contained in the 
ocean and other waters must be in intimate relation with their 
organic life, and that, consequently, the greater or lesser abun- 
dance of fossils in certain formations must bear some relation to 
the quantity and nature of the gases contained in the sea in which 
they were deposited, and these gases were in relation to the volume 
_ and constitution of the then atmosphere. Thus we have probably, 
in the fossils of the different formations, real measures of the 
atmospheres, corresponding to the periods of their deposition. 
Were it possible to determine directly the gases given forth 
from any one of the existing active volcanoes, no more valuable 
scientific work could be attempted, but the difficulties are evidently 
immense, if not insurmountable, unless in the case of some small 
volcanic cones, where it might be possible to make such an attempt. 
But these difficulties only enhance the value of all measurements 
and determinations of the emissions of gaseous hot springs and 


28 Scientific Proceedings, Royal Dublin Society. 


cold springs, which may be considered as bearing some relation to 
the total voleanie activity. 

The oil-springs of America and of the Caspian must be con- 
sidered as coming into this category, since, by their constitution, 
they are akin to certain of the gases which accompany volcanic 
action, and nothing yet absolutely proves their organic action. 

With this continuous emission of gases and steam must in 
some way be connected the slow movements of the earth’s surface, 
which are now being more attentively studied than had been the 
case; and did we posses sufficient data in respect of these emissions 
in toto, it might be possible to foresee the recurrence of volcanic 
eruptions, or of earthquakes, and of disturbances of the earth’s 
surface. Still more important is the bearing of this total emission 
of gases and vapour on the question of the radiation of earth heat 
into space. As the points from which the gases come are certainly 
situated at relatively great depths, and in the case of such eruptions 
as that of Krakatoa most certainly at a very great depth, the surface 
radiations must be considered as forming part of a total radiation, 
some terms of which correspond to points deep in the interior of 
the earth. That the seat of the great explosion of Krakatoa was 
very deep may be inferred from at least two facts—the one, that 
the ‘ recoil’”’ (to use the expression) of the explosion was felt at or 
near the antipod of that point, as observed by Monsieur Forel in 
Nature, March 26, 1885. He states that underground noises were 
heard at Caiman-Brac, in the Caribbean Sea, in August, 1883, 
contemporaneously with the eruption, the exact antipod of Krakatoa 
being the middle of the State of Colombia, on the Magdalena river, 
between the towns of Antigua and Tunja. 

_ Another fact which would lead one to infer that the seat of the 
explosion lay very deep was, that the island was split according to 
an east-to-west direction, so that the whole northern part became 
detached, and sank to a depth of 200 m., or more. “Inthe place 
where the fallen part of Krakatoa once stood there is now every- 
where deep sea, generally 200 m.—in some places even more than 
300m.deep” (Nature, vol.xxx. p.12). Now this splitting in an east- 
to-west direction may perhaps be considered as the result of the 
lateral pressure and intense friction of the solid matter, when being 
ejected, against the west side of the vent, since coming from a 


O’Remty—On Gaseous Products of Great Eruptions. 29 


great depth, and having only the initial angular velocity corre- 
sponding to that depth, it should lag more and more as it rose to 
the surface of emission. This lateral pressure and friction would, 
to a certain extent, explain the comminution of the lava, and the 
formation of the very fine dust. 

That Krakatoa, and indeed the whole of Java, having for 
antipod the north-western coast of South America, must in like 
manner, to some extent, feel the “‘recoil”’ of eruptions and earth- 
quake shocks happening in the latter localities, may be expected, 
since we have here the occurrence of the exceptional case of land 
having for antipod land, and as can be seen at a glance of the map 
exhibited, showing the antipodes of the countries of the Hastern 
Hemisphere, South America, and part of Asia correspond in a 
very remarkable manner, while at the same time they represent 
the most active seats of volcanic and earthquake action. Were 
the soundings of the ocean and our bathymetrical maps complete 
in this respect, and could these soundings be verified periodically, 
it would perhaps be found that, corresponding to the volcanic and 
earthquake actions which take place in one hemisphere, move- 
ments of the bottom of the ocean take place in the opposite hemi- 
sphere, and that thus the deformations resulting from a continual 
contraction are being balanced, so as to maintain the uniformity 
of the earth’s movement. 

There is one last point relative to the great eruption to which 
I venture to call attention; it is that of the periodicity of such 
great outbursts. 

One of the remarks made relative to Krakatoa in the article of 
Nature already referred to, vol. xxx. p. 10, is, that the volcanoes 
of the Straits of Sunda had been in a state of quietude during 
200 years, and that during the latter years a great many earth- 
quakes took place along the fissure on which they are situated. 
Now, in the same vol., p. 435, is a very interesting article on the 
frequency of earthquakes in Japan, It is stated that the Japanese 
have attempted to prove that earthquakes run in well-defined 
cycles, a by no means novel or very modern idea. Wernich, in his 
Geographische Medicinische Studien, says “that severe earthquakes 
occur in Japan every 20 years.” The Japanese journals, working 
on records relative to the period included between the dates 


30 Scientific Proceedings, Royal Dublin Society. 


A.D. 628 and a.p. 886, have divided it into 26 periods of 10 years, 
between which the following intervals occur :— 


40 years between the 2nd and 6th, 


COte i da oy Aida. 
40 ,; i thy Sy llothe 
40 ,, a NGthin es, 20th 
40 ,, i 20th Zande 


and from ‘the author’s explanatory notes a still more correct 
table can be deduced, by means of which the cycle of earthquake 
intensity is finally put at 33°3 years, or 38 x 11:1, that about 
three times the sun-spot cycle (Lockyer gives 10 years; Flammarion 
112). 

A further deduction is made, that earthquakes of a disastrous 
nature occur once every 59 years, so that the next great catastrophe 
may be expected in 1913. 

Now it will be remarked that the interval of 200 years of rest 
mentioned for Krakatoa so far corresponds to a multiple of the 
short period of 10 years, adopted as interval of groups, represent- 
ing also the period of sun-spots. | 

Admitting that the earth were once in a state somewhat as 1s now 
the sun, may it not have had in a similar manner a recurrence of 
phenomena such as the sun-spots, and may not this recurrence be 
still observable in the existence of a period or cycle in volcanic and 
earthquake action? When working at the Catalogue of European 
earthquakes which I submitted to the Royal Irish Academy last 
April, I noted a recurrence of a period or interval of 10 years in 
many cases, but so exceptionally that I could not point to it as 
a law; however, a further examination of the data existing may 
be more conclusive in this respect. 


[-—) 


31] 


IV.—ON A NEW SPECIES OF OROPHOCRINUS (PENTRE- 
MITES), IN CARBONIFEROUS LIMESTONE, COUNTY 
DUBLIN. ALSO REMARKS UPON CODASTER TRI- 
LOBATUS (M‘COY), FROM CARBONIFEROUS LIME- 
STONE, COUNTY KILKENNY. By WILLIAM HELLIER 
BAILY, F.L.8., Htc. (Prats 1.) 


(Read, February 16, 1885. ] 


ORoPHOcRINUS (PENTREMITES) PRELONGUS (n.8.) : 


This Blastoid is remarkable for its size and elongated charac- 
ter, compared with others of the genus. 

Its general outline is that of a lanceolate body (calyx), with a 
pentagonal summit, its greatest diameter being at the termination 
of the ambulacra eight-tenths of an inch from the summit, decreas- 
ing regularly towards the base and terminating obtusely, without 
any trace of stem. 

The basal plates, conical in shape, extend upwards to about 
one-third of its length, measuring nine-tenths by seven-tenths of an 
inch; the radial plates are oblong, one inch and a-half by three- 
quarters of an inch at the widest part; the deltoid plates are small 
and triangular, extending only to about three-tenths of an inch from 
the summit, the five plates forming a pentagon when viewed from 
above. : 
The ambulacra are narrower than in O. inflatus; the small plates 
composing each are arranged in two alternating series, with a deep 
groove down the centre, and are inclined towards each other at an 
angle of about 15°; there are sixteen of these plates in the space 
of a quarter of an inch. 

The mouth, which was small and central, and ovarian apertures 
are not sufficiently well shown for description. 

Length, two inches and five-tenths; breadth at widest part, 
one inch and six-tenths. 

Plate 1., figs. 1, la, 2, 2a, 2. 

Localities.—St. Doolagh’s and Raheny, Co. Dublin, in fouee 
carboniferous limestone; collection, Geological Survey of Ireland. 


32 Scientific Proceedings, Royal Dublin Society. 


CoDASTER TRILOBATUS AND acuTus, M‘Coy: 


Of this genus (belonging to the same class of Hchinodermata, 
the Blastoidea), established by M‘Coy under the above name,’ he 
describes two species which appear to be identical. 

Some years ago I was fortunate enough to collect several well- 
preserved specimens of this fossil, which I refer to C. trilobatus, as 
indicative of the most usual form, resembling very much that of a 
hazel nut, although there are gradations between both that and 
the variety M‘Coy has figured under the name of C. acutus. 

As I believe it has never yet been recorded from Ireland, I now 
bring it before the notice of this Society. 

Our specimens were obtained from shales between the carboni- 
ferous limestone at an old quarry at Lisdowney, near Ballyragget, 
county Kilkenny; collection, Geological Survey of Ireland. 

Its locality in England is stated in the Synopsis to be Bolland, 
Derbyshire. 

Plate 1., figs. 3, 4, 4a, 48, 5, 5a. 


NOTE ADDED IN THE PRESS. 


Since this Paper was read, Messrs. P. Herbert Carpenter and 
Robert Etheridge, Junior, who are studying the subject, requested a 
loan of the specimens, which, at their request, were submitted to them 
for their examination. Although agreeing with me that figs. 1, la 
represent a new species (Pentremites prelongus), they consider the form 
represented on figs. 2 and 2a as a different species (Orophocrinus pen- 
tangularis, Miller sp.). 


1 Synopsis of British Paleozoic Fossils, 1885, pp. 122, 123, pl. 3p, figs. 7, 8; 
Ann. and Mag. Nat. Hist., 2nd series, 1849, vol. iii. 251. 


Batty—On a New Species of Pentremite, &c. 33 


EXPLANATION OF PLATE I. 


Fig. 1.—Orophocrinus (Pentremites) prelongus, Baily. Lateral view, 


-, AID, 
<1 Ya =D Oy 
9 Ao IDO, 
a4 | Pol Doe 


s, 45 De, 
> 4 ID e. 
», 48.—Do. 
5 b> SD. 
3) OA. Do. 


natural size, from carboniferous limestone, 
St. Doolagh’s, Dublin. 


do. Section of ditto. 


do. Natural size, carboniferous limestone, Raheny, 
Dublin. 


do. Natural size, view of the summit. 


do. Portion of ambulacral area enlarged three dia- 
meters. 


3. —Codaster trilobatus, M‘Coy. Lateral view, natural size. 


do. var. acutus, M‘Coy. Lateral view, natural size. 


do. do. Ventral surface of same, showing pen- 
tagonal mouth and ovate anal aper- 
ture, natural size. 


do. do. One of the ambulacral areas of same, 
showing perforated plates, and in- 
termediate jointed ridges, enlarged 
four diameters. 


do. do. Small ovate specimen, natural size.. 


do. do. Basal view of same, natural size, show- 
ing convex central disk perforated 
for attachment of stem. 


Figs. 3, 4, and 5 from specimens obtained in shales of lower carboni- 
ferous limestone, Lisdowney, near_ Ballyragget, county Kil- 


kenny. 


SCIEN. PROC. VOL. V. PT. I. 


Scientific Proceedings, Royal Dublin Society. 


34 


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Proceedings of the Royal Dublin Society. 


36 


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Kinanan—On the Irish Lower Paleozoic Rocks, &¢. 


“SOLIOS 
qoddn oy} JO syoor oy} sv uwozttoy ous oq} 
uo ATqeqord ore ‘Tesouog Ayun0d 04 Jo YNOs 
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Proceedings of the Royal Dublin Society. 


38 


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‘(SdUd-aDVSSV) ANOUH OINGIW 077 bupnjow ‘sNVIMaNVD 


39 


Kinanan—On the Irish Lower Palwozoic Rocks, &e. 


“STOY}ZO OY} UL} YZa.19S~p ‘CQ 0} pore or0ul 
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bared « 


VI.—ON THE OCCURRENCE OF AN OUTLYING MASS OF SUP- 
POSED LOWER OLD RED SANDSTONE AND CONGLO- 
MERATE IN THE PROMONTORY OF FANAD, COUNTY 
DONEGAL. By EDWARD HULL, LL.D., F.R.8., Director 
of the Geological Survey of Ireland. 


[ Read, December 16, 1885. | 


Tue district where this mass occurs lies between Lough Swilly and 
Mulroy Bay, and is formed chiefly of metamorphic beds of quartz- 
ite, schist, trap, and crystalline limestone.- The tract of Lower Old 
Red Sandstone lies along the northern base of the Glenalla Hills, 
rising into a high ridge of quartzite, &c., which strikes across the 
promontory in a N.H. and 8.W. direction, and attains to an eleva- 
tion of 1,196 feet. The beds of sandstone and conglomerate are 
let down by a large fault against the older rocks, and form a'low, 
rocky tract, lying for about two miles along the northern base of 
the mountain, and were recognized by the officers of the Geological 
Survey when engaged in that district during the summer of this 
year. They consist of alternating beds of reddish soft sandstone, 
generally pebbly, and often forming massive conglomerates, with 
large blocks of quartzite, schist, limestone, and trap. 

The dip of the beds is 8.8.E., or towards the base of the quartz- 
ite ridge; and, measured across the strike, the mass is one-quarter 
of a mile across, and the estimated thickness is about 800 feet. 
Red shales, and flaggy sandstones also occur, and are seen resting 
unconformably on the quartzite beds of the metamorphic series. 

From the general resemblance of these beds to those referable 
to the age of the Lower Old Red Sandstone in the district of 
Omagh and Dromore to the south, as also on the coast of Antrim 
and Scotland in an easterly direction, I am disposed to refer them 
to this formation, rather than to one of a more recent period, such 
as the Carboniferous; but in the absence of fossils and the entirely 
isolated position of the beds, the question of their geological age 
must remain somewhat indeterminate. They seem to have been 
formed within the limits of a basin separated from any of the other 
basins of Lower Old Red Sandstone either in Ireland or Scotland, 
and will prove a new feature in the Geological Map of Ireland. 


ye se 


VII.—_ON A METHOD OF DETERMINING THE SPECIFIC 
GRAVITY OF SMALL QUANTITIES OF DENSE 
OR POROUS BODIES. By J. JOLY, B.E., Assistant 
to the Professor of Civil Engineering, Trinity College, 
Dublin. 


Read, January 20, 1886. 
y v, 


A muTHOD of determining the specific gravity of a small quantity of 
a heavy mineral is often a desideratum in the course of inquiries into 
the composition of rocks, sands, volcanic ash, &e. The mineralogist 
is indeed frequently called upon to determine the nature of minerals 
distributed ,but sparsely throughout his specimen, or even when 
abundant—from the intimateness of their intermixture with other 
substances—only procurable in very small fragments, and, except 
with the expenditure of much time and labour, in very small 
quantities.; The same case arises when it is not desirable to deface 
an implanted specimen of rare beauty of form. Finally, the 
chemist is often called upon to determine the physical properties 
of minute quantities of matter, as in the case of the rare elements. 

Whether as a characteristic for discrimination, or as a physical 
property to be placed on record, the quality of specific gravity is 
of sufficient importance to justify me in calling your attention to 
amethod of determining it, specially applicable for dealing with 
small quantities of very dense bodies, and also with small quanti- 
ties of porous, fibrous, or very cleavable bodies. 

The method,now in general use for the micro-determination of 
the specific gravities of silicates, &., of low density is by balancing 
in a liquid of a specific gravity, adjustable to that of the specimen, 
and subsequently determining the density of the solution em- 
ployed. 

This method fails altogether— 


(a) When the substance has a specific gravity—over four. 
(0) When the substance is of a porous nature. 


In the first case the method fails, for want of a liquid of 
sufficient density to equilibrate the solid. Indeed we cannot 
E 


SCIEN. PROC., R.D.S., VOL. V. PT. II. 


42 Scientific Proceedings, Royal Dublin Society. 


readily extend the method above the specific gravity 2:77, that of 
Thoulet’s solution (the mutually-saturated solutions of biniodide 
of mercury and iodide of potassium). The solutions necessary to 
extend the range above this are either costly or difficult to work 
with: some can only be used by maintaining them at a high 
temperature (as lead chloride at 400° C.). In any case the range 
of density hardly passes that of garnet, 3-4 —- 4:3, and [ am not 
aware of any other published method of dealing with small frag- 
ments of minerals of a specific gravity exceeding this. In short, 
if a few milligrams of any of the host of minerals ranging above 
4-5 in density—about 90 per cent. of the unsilicated mineral 
species—be presented to the ano 8 he is unable to deter- 
mine this eharacteristic. 

In the second case—the case of porous bodies—the impossi- 
bility of freeing the body from contained air, when immersed in 
liquids of the nature of those to which we are restricted, renders 
the method fallacious. ‘The air-pump or the application of heat. 
will generally be found of little avail. In this case we must again 
seek a large quantity of the substance, so that we may be able to 
weigh it in a liquid of low-surface tension, or of a ‘ creeping’ 
nature, such as turpentine or alcohol. Small quantities cannot be 
dealt with. 

The method to be now described enables the specific gravity of 
substances to be determined under both these conditions—that is, 
whatever their density or whatever their state of aggregation—in 
extremely minute quantities, with an accuracy limited only by the 
sensitiveness of the chemical balance, and by the aid of solutions 
of a density varying from about that of water to say twice that of 
water: but this is under our own control. Unfortunately, it is 
inapplicable to the purpose of effecting the separation of bodies of 
different specific gravities. 

Briefly, the theory of the method is as follows :—The mineral 
by itself will not foat in any known solution, suppose. If, how- 
ever, we mix it with another substance of much lower specific 
gravity, there is easily found such a proportion for the constituents 
as will enable the mixed bodies to be equilibrated by dilution of 
the specific gravity liquid. We may, in short, adjust the specitic 
gravity of the mixed substances to be as close to that of either of 
them as we please. 


Joty—On a Method of Determining Specific Gravity. 43 
We require to know— 


W the weight of the mineral, 

w . ap » buoyant substance, 
o » sp. gr. ,, buoyant substance, 
s Be Re », mixed substances, 


in order to determine S, the specific gravity required. 


Then, as 

ih iy di weight 
P- Br volume’ 
W 

. Wiw w 

are hae 

Wes 

o PG Gio) aH 


By this means, then, we can evidently deal theoretically with 
bodies of any specific gravity; and, further, if for the buoyant 
substance we chose one which, when brought to a liquid state, will 
creep into and surround the substance, we may evidently be inde- 
pendent of conditions of aggregation, and all trouble with con- 
tained air, or bubbles adhering to the surface of a rough fragment, 
avoided. 

How the method is practically carried out I now proceed to 
describe. 

The specific gravity of a piece of translucent, homogeneous 
paraffin, free from bubbles, is taken by any of the ordinary 
methods—weighing in water with a sinker, or balancing in a. 
mixture of alcohol and water, and then determining the density 
of the solution. The value found is what I called o above, the 
specific gravity of the buoyant substance. There is no better 
paraffin for our purpose than that sold in the form of candles; 
nor do I see any reason to seek any other substance. It fulfils 
all requirements, its penetrativeness when melted and its trans- 
lucency when solid leave nothing to be desired. 

K 2 


44 Scientific Proceedings, Royal Dublin Society. 


From this piece of paraffin a little disk-shaped piece—about 
3 or 4 mms. in diameter, and 1°5 mm. thick—is cut with a sharp 
knife, cleanly paired and smoothed on the edges by gently rubbing 
between the fingers. The disk is larger or smaller according to 
the quantity of mineral at our disposal, and if great accuracy 
be desired we determine its specific gravity, thus avoiding any 
assumption as to the homogeneousness of the piece from which it 
is cut. There will be in general, however, no need of doing so: 
thus compare the two following specific gravities obtained—(1) on 
a piece of paraffin weighing over 11 grms.; (2) on a little disk 
removed from this, and weighing about °04 gram. (2) was deter- 
mined’ by balancing in dilute alcohol :— 


(1) 0:9204 
(2) 0-9208 


An inappreciable difference of specific gravity. 


The disk removed is next weighed in a delicate balance. If: 
as small as described above, the balance should read definitely to 
0-2 mgr. Its weight is w in the equation. It is in all cases 
manipulated by use of a clean ivory forceps. If very minute it is 
weighed on a tarred watch-glass, and so need not be manipulated at 
all after preparation. Removed from the balance, the small frag- 
ment (or fragments) of mineral is placed upon the surface of the 
disk. The extremity of a slip of copper, about 5 mms. wide, is 
now heated in a smokeless flame—it is better to use a little copper 
ball, drilled and fitted on to a fine steel knitting-needle—and held 
above the fragment of mineral, care being taken not to approach 
it so closely as to endanger the paraffin being volatilized or of its 
being melted so far as to risk loss by running over. Preferably 
the disk of paraffin should rest on a piece of wet filter paper, or on 
an anvil of clean copper; this will keep the lower surface cool. 
In point of fact, the mineral in general absorbing heat more freely 
than the paraffin, melts the paraffin beneath it by conductivity, 
and there is little risk of loss. The heating is continued till the 
mineral is seen to be completely soaked with the paraffin—every 
erack and cranny is then filled, the paraffin welling up and 
swallowing the specimen and expelling all trace of air. 


Joty—On a Method of Determining Specific Gravity. 45 


_ When cold it is placed in the balance and weighed. By sub- 
tracting w from the weight found, we have W, the weight of the 
mineral. 

There is probably no loss of paraffin in this process. Thus it 
will be found that if such a pellet be very carefully balanced in a 
solution, removed, dried, and melted on the hitherto unaltered 
face of the disk, and then replaced in the solution, there is, if 
anything, a slight decrease of density ; on complete cooling this 
decrease is inappreciable. 

The pellet is now dropped into a specific gravity solution. A 
saturated solution of common salt and water (sp. gr. about 1:2) 
will in many cases be found sufficient to float it. If so, we have 
merely to adjust by adding water. Otherwise we resort to Thoulet’s 
solution (“ Minéralogie Micrographique”’, Fouqué et Lévy, p. 118). 

I have prepared no pellets approaching this density—2:77— 
but I prefer the use of this solution in all cases; it seems to con- 
centrate less rapidly by evaporation, and is more “creepy”. It 
should be preserved and reconcentrated by evaporation after use. 

In this operation of balancing it is advisable to use a camel’s 
hair-brush for stirring, and also for conveying small quantities of 
liquid when finally adjusting—a process of much delicacy. The 
brush is also used for removing bubbles from the pellet, which, 
however, will be found to give little trouble if the solutions be 
previously boiled to expel air. If the mixed solutions containing 
the pellet be left standing for some hours before finally adjusting, 
‘it will be found on examination with a lens that bubbles will no 
longer gather on the paraffin. Should it be desired to preserve the 
adjusted solution for any little time, the final adjustment should 
be effected in a stoppered bottle, otherwise concentration will occur 
in a very short time on exposure to the air. 

The last operation is finding the specific gravity of this solution, 
which gives us s in the formula. ‘This is most accurately done in 
a Sprengel tube, holding about 5 ces.; the bottle may also be used. 

The following Table records the results of ten experiments, 
made in verification of the method. I have altogether made ‘but 
twelve experiments—one was spoiled by overheating and losing 
some of the paraffin by overflow; the other by inadvertently 
touching with the heater, and thus drawing off a little paraftin. 


46 Scientific Proceedings, Royal Dublin Society. 


I went through with these experiments, and obtained results 
revealing sensibly the loss of buoyant material. 

Thanks to the translucency of the paraffin we are able to 
examine minutely the appearance and condition of the mineral 
when imbedded. J have here under the microscope the pellets 
made up for these experiments. If you will examine with this 
1” objective the appearance presented by the gold of experiment 
7, of the cuprite of experiment 10, you will obtain some notion of 
the efficacy of the melted paraflin to penetrate and surround loose 
and dendritic bodies. The fragment of cuprite is about twice the 
size of a pin’s head; it is a maze of little exquisite octahedrons, — 
deep blood-red in colour, and with fine translucency. Around it 
the disk of paraffin is uniformly translucent; through it the paraffin 
has permeated completely, not a crack or bubble visible. Similarly, 
the gold seems not less perfectly embalmed beneath its silvery 
veil—free from any visible blemish to mar the accuracy with which 
we measure its volume. 

Of experiments 4 and 9 it is interesting, perhaps, to note that 
4 was undertaken with the notion that the mineral being dealt 
with was barite. Its weight, as a hand specimen, was deceptive, 
it being penetrated by sphalerite. On getting the result (2°78) it 
was concluded that an oversight had been made somewhere in the 
measurements, and experiment 5 was undertaken; this giving 2°77, 
the specimen was appealed to. Tests then showed it to be calcite. 

I have thought well to include in the Table some of the quanti- 
ties obtained in working the formula, as bearing on the scale on 
which the experiments have been made. It is evident that the 
method can be applied on a much smaller scale still. 


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VIII.—NOTES ON THE MINERALS OF THE DUBLIN AND 
WICKLOW GRANITE. I.—THE BERYL AND IOLITE 
OF GLENCULLEN. By J. JOLY, B.E., Assistant to the 
Professor of Engineering, Trinity College, Dublin. (With 
Prares II., II11., and IV.) 


[Read, November 18, 1885. ] 


Tne beryls described in the following pages occur in the granite 
exposed in the quarries of Glencullen, Co. Dublin, close over the 
little stream, Cookstown River, which flows into the village of 
Enniskerry, some three miles further on. ‘These quarries are 
situated about one mile from the junction of the granite with the 
schist. Other and larger quarries opened higher up on the same 
side of the valley yielded, on examination, only one small specimen. 
In the lower quarries these beryls occur in abundance—an abun- 
dance equalled by no other locality in the Dublin and Wicklow 
granite, so far as I know. 

I can find no previous mention of this locality anywhere in 
published records.1_ In Weaver’s remarkable and beautiful work 
on the geology of Eastern Ireland’ the locality is unmentioned. 
Weaver was the first to find beryls in the granite. It is strange 
that the Glencullen beryls escaped notice so long. The quarries 
are very old, and beryls have occurred in them, I am informed by 
the quarrymen, from the first. 

The crystals, which are sufficiently remarkable in habit and 
structure to justify close investigation, occur in veins and bunches 
throughout the granite, generally coarsely crystallized in their 
immediate neighbourhood. Orthoclase, especially, occurs in re- 


1 Prof. J. P. O’Reilly’s visit (Proc., R. D.8., vol. iv., p. 505) was made some 
months after mine, which took place in January, 1836. 

2 «‘ Memoir on the Geological Relations of the East of Ireland,” by T. Weaver. 
From vol. vy. of the Transactions of the Geological Society of Ireland, 1819. This 
work is too much neglected: the engravings of mountain profile are exquisite; the 
letterpress, with all the freshness of ‘‘ the Complete Angler,’’ is a record of patient and 
conscientious research. 


Joty—On the Minerals of the Dublin and Wicklow Granite. 49 


markably fine crystals. Tourmaline, which most generally is part 
of the immediate matrix of the more highly altered beryl, occurs 
plentifully. Mixed with kaolinized matter, it is moulded often in 
very large masses to the beryl, rarely penetrating the hexagons. I 
possess, however, a specimen of beryl—from the Ballybetagh 
quarry—in which a crystal of tourmaline, to all appearance, passes 
through a well-formed hexagon from side to side. The beryl has 
been altered, however, which, as we will see, probably affords an 
explanation. 

The beryls of Glencullen present three types: normal crystals, 
_ radiating crystals, and altered crystals. 


1. Norma BrEryu. 


Pale apple-green; semi-transparent to translucent. Also yellow; 
semi-transparent to translucent. Only faces detinitely shown, base 
and prism. The yellow varieties often present, on breaking the 
crystals across, a core of green-coloured beryl. 

Specific gravity = 2°722; taken on a large green hexagon 
weighing 86 grammes. 

Sections of these beryls, taken parallel to prism faces or to basal 
faces, show numerous enclosures, vitreous with bubble or liquid 
with bubble ; congregated in nebule or arranged in strings. These, 
taken at right angles to optic axis, show want of uniformity in 
extinction between crossed nicols. There is a cross-hatched appear- 
ance, as if the mineral was not crystallographically homogeneous 
throughout. Des Cloizeau, on optical grounds, considered beryl as 
probably possessing two optic axes close together.—Minéralogie, 
p- 366, vol. 1. 

These normal beryls cohabit with muscovite, which often closely 
adheres over their prismatic faces. In size, crystals measuring 
a couple of centimeters across the prism face are not uncommon. 
Some years ago I took a crystal from the small opening in the 
granite at Ballybetagh, which measured about 4:5 cm. across the 
prism faces. 

Interpenetration by orthoclase is common in these crystals. I 
have not seen any definitely penetrated by either mica or quartz. 

Beryl is not a phosphorescent mineral: if, however, some of 
these crystals be heated in a dark room they will be found to 


50 Scientific Proceedings, Royal Dublin Society. 


become luminous here and there over their surface. This, I ascer- 
tained, was due to the fragments of orthoclase adhering to the 
hexagons. Mr. Moss has been aware of this peculiarity of the 
Dublin orthoclase for many years, having, like myself, discovered 
it accidentally. 


2. RavDIATING BERYL. 


This second type differs from the first in habit only, but this 
habit is one not noticed in the descriptive mineralogies, and 
evidently, at any rate, developed in the crystals found at Glen- 
cullen to a rare degree of perfection. 

The crystals radiate in the most regular and striking manner, 
not alone fanwise, but as cones or sphere segments. The pris- 
matic form seems fully preserved in the individual crystals, but 
each crystal is tapered, dwindling at last to the common centre of 
radiation. For some distance around this centre no structure, other 
than radiating lines, is indeed noticeable: further out the crystals 
individualize, and their prismatic form is apparent. If a chip 
from near the centre of one of these cones is placed between crossed 
nicols it is found to extinguish parallel to the radiating lines ; hence, 
the fact that the axis of the prism lies along these lines is almost 
assured. 

A section taken through the centre of a small group of radiat- 
ing crystals revealed strongly-marked cleavage along the radii, a 
cleavage at right angles to this also well marked, and faint cleav- 
age lines intersecting at about 100°, this angle being external to 
the centre, and bisected by the radii. Countless enclosures, mostly 
vitreous, are present, generally elongated along the cs these 
“are very minute. 

These radiating beryls are pale-green, inte -green, yellow, 
and yellow-brown; translucent to opaque, when they are often 
quite white in colour. Sometimes they are highly altered when 
they fall under the third type, where they will be described. 
Basal cleavage cracks cross the radii in lines roughly circular 
round the centre of radiation. The crystals easily break along 
this cleavage, producing a stepped appearance along the radii. 

The groups are all more or less fan-like in section, that is, the 
cone seems never to merge into the sphere; they are occasionally 


Joty—On the Minerals of the Dublin and Wicklow Granite. 51 


very small, often only a couple of centimeters in diameter, and 
frequently appear on the surface of the granite in great numbers 
imparting a very extraordinary appearance to the rock. The 
figure on plate 1v. from a photograph, shows a very lovely speci- 
men full size. It is of a delicate pale, bluish-green colour; trans- 
lucent. The radii pass through the block of granite removed with 
it, appearing in coarse, crowded, hexagons on the other side, and 
‘mixed with tourmaline. They are there of a rusty-brown colour. 
Some of the crystals must scale over 15 cms. in length. This 
specimen was found by Mr. Gerald Stoney, in company with - 
Mr. K. Doyle. 

The specific heat! of Glencullen beryl, taken by the method of 
condensation, was found to be 0:21401. The specimen used was a 
green crystal taken from a group of radiating prisms. 


EXPERIMENTS ON LOSS OF CoLouR. 


It has long been known that emeralds calcined at a low red 
heat lose colour, becoming white and opaque, and parting with 
water and organic matter. Such are the results of Léwy’s experi- 
ments, who ascribes the colour of emeralds to the presence of 
organic matter. 

It appeared of interest, as throwing some light on the history 
of these beryls, and on that of the granite containing them, to 
repeat the experiment, and if possible fix an inferior limit to the 
decolourizing temperature. 

Experiment 1.—A preliminary experiment on some fragments 
of green beryl showed that a temperature far below that of red 
heat sufficed to bleach and render opaque. The fragments were 
heated on copper foil, over a fire for a few minutes, they could 
almost be handled immediately on removal. 

Experiment 2.—Fragments of green and yellow beryl, dropped 
into a test tube containing boiling mercury, lost nearly all colour 
after about one hour’s heating. 

Experiment 3.—Fragments of green and yellow beryl, sealed 


1] hope shortly to publish an account of this method of investigation, and of the 
means by which I hope to make it generally ayailable. 


52 Scientific Proceedings, Royal Dublin Society. 


in a glass tube containing air, and dropped into a tube containing 
boiling mercury, lost nearly all colour after an hour’s heating. 

Experiment 4.—Fragments sealed in a glass tube containing 
air, and heated for five hours to a temperature of 180°C. (in a 
bath of boiling carbolic acid) suffered no change. 

Experiment 5.—Other specimens, heated by means of a sul- 
phuric acid bath to a temperature of 200° C., rising to 250° for 
about six hours, showed no change. 

Experiment 6.—Bits of green and yellow beryl 'placed in an air 
bath, retaining a temperature of about 230° C. for thirty hours 
showed a decided Joss of colour. 

Experiment 7.—Boiling in water did not restore colour to the 
decolourized specimens; nor has it returned since (after forty 
days). ‘The specimens of experiments 2 — 7 retain translucency. 

Conclusions.—It appears from experiments 2 and 3 that a 
temperature of 357° C. (the boiling point of mercury) is sufficient 
to deprive both green and yellow beryls of colour in a very short 
time, and that whether in contact with the air or not. Hxperiment 
6 shows that the temperature of alteration may be taken, probably, 
as well inferior to 350° C.; with long-continued heating possibly 
below 250° C. 

On the nature of the change effected in these beryls by heating 
I am unable to give an opinion. Their continued translucency 
shows at any rate that the change is not produced in a mechanical 
way—as it might be—by the development of very numerous 
eracks. 

I would suggest that this phenomenon bears on the history of 
rocks containing this mineral. These green and yellow beryls to 
be found nested far and wide throughout our Dublin granite are 
in short so many maximum thermometers. Their delicate and 
beautiful colours indicate a major limit to the changes of tempera- 
ture experienced by the granite since their formation to the 
present day. 


3. ALTERED BERYL. 


The third type, which may be described as altered beryl, includes 
the larger portion of the total number of crystals coming from 
Glencullen. I have found also similar crystals at Ballybetagh and 
in Killiney granite. 


JoLty—On the Minerals of the Dublin and Wicklow Granite. 58 


Externally they show well and sharply-developed faces, both 
prismatic and basal, and the angles of the hexagonal prism. But 
here the resemblance to beryl ends ; they are neither transparent 
nor translucent. The vitreous surface and homogeneous appear- 
ance of beryl are wanting. They are opaque, dull, rough, and 
piebald: some dull green and white, some dull green and dull 
rusty brown. ‘They are in fact a different mineral from beryl in 
all but external form. They are found up to about half a kilo in 
weight. Sometimes the cores of the hexagons are eaten out into a 
cavernous tube lined with rusty matter. Occasional cracks crossing 
the prism recall the imperfect basal cleavage of beryl. 

Their specifft gravity shows at once that they are not, or only 
in part, composed of beryl. I found it to be 2°620 taken on a 
specimen of average appearance, free from hollows, weighing fifty 
grammes. The lowest specific gravity recorded by Dana is 2°63; 
by Des Cloizeau 2°67. I have mentioned that the specific gravity 
of a specimen of normal beryl from Glencullen was found to be 
2°022. 

The specific heat is hardly abnormal so far as my experiments 
on beryl go. ‘Three experiments were made on the same specimen 
used in ascertaining specific gravity :— 


(a) 0:21554. 
(0) 0:21446. 
(c) 021691. 
Mean specific heat = 0°21563. 


On breaking up the crystals they are found to present inter- 
nally the same appearance as regards colour and lustre as exter- 
nally. 

T have seen no complete hexagons of this altered beryl. This 
is noteworthy. One side or one end of the hexagon invariably 
passes insensibly into the orthoclastic matrix, that again insensibly 
passing into granitic mixture with quartz and mica. ‘Tourmaline 
abuts against the faces in many cases, but is easily peeled off, 
leaving a clean, smooth surface beneath. It does not penetrate or 
grow into the prism. With the orthoclase it is different. It is in 
that case impossible to say, on a fractured surface, where ortho- 
clase begins or prism ends. Nor are these crystals ever found 


o4 Scientific Proceedings, Royal Dublin Society. 


implanted on quartz only, as is common with normal beryls from 
Glencullen. 

I had a section from one of these crystals prepared for the 
microscope by Mr. Gregory, of London; it was, by my directions, 
taken parallel to one of the prismatic faces. ‘The specimen was in 
colour mottled green and white, with some rusty marks. 

On examination in the polarizing microscope it appeared, in 
the first place, that more than one mineral entered into the com- 
position of these erystals. ‘The fundamental constituents were 
evidently two in number. There was a constituent presenting the 
appearance of a felspar, and there was a more homogeneous con- 
stituent, which I suspected to be beryl. ‘These were mixed, archi- 
pelago-like, in wild confusion, but always quite distinct. The 
felspathic part extinguished locally or in plumed shadows, which 
crept over the field as the stage was rotated. Faint cross-hatching, 
checquered or wavy marks, recalled microcline: these marks appear 
in fig. 3, pl. m1. Such are, however, common in well-authenti- 
cated orthoclase. It showed, too, the habitually quiet colours of 
that felspar, slate-grey in this case; and in fact I had little doubt 
it was orthoclase. Lately, however, examination of the cavities 
eaten in these crystals by decomposition has set the question at 
rest. In these, bunches of small laminate crystals, resembling 
white orthoclase in appearance, branch from the walls in tufts and 
plumes; their grouping suggestively recalling the plume-like 
extinctions obtained on the sections. Fragments of these tufted 
crystals, removed and placed in a diffusion zone above Thoulet’s 
solution, according to the simple and accurate method devised by 
Professor Sollas, float side by side with the Glencullen orthoclase. 
Their specific gravities are, therefore, identical, Again, when 
compared with Glencullen orthoclase on the Meldometer their 
melting points are found to be identical. There is little doubt, 
then, that this constituent is orthoclase. 

It is seen at once on the section that this orthoclase includes a 
ereat many sharply-defined, brilliantly polarizing crystals, present- 
ing a very beautiful appearance. ‘hey are very small, and, with 
great probability, are iolite. 

In the second principal constituent extinction is not local, but 
takes place simultaneously all over the field, leaving the felspar 
standing out in luminous veins and patches.—Fig. 1, pl. u. (x 18 


Joty—On the Minerals of the Dublin and Wicklow Granite. 55 


diams.) It polarizes in bright colours uniformly, and generally 
appears limpid and clear, save for conspicuous cleavage streaks. 
It is bordered where abutting on the felspar, with a dark margin, 
due to difference of refractive index. | 

It will be evident that if this constituent is beryl, and the 
streaky lines alluded to basal cleavage, not only should we expect 
simultaneous extinction, but we should expect it to occur when 
these lines are in the plane of analyzer or polarizer, the axes of 
elasticity of the section being then contained in these planes. On 
trial it is found to happen so. 

Again, in the case of a section cut in a plane at right angles to 
the one being described—that is, at right angles to the axis of the 
prism—this same one of the two constituents should behave as if 
amorphous: that is, remain dark all round between crossed nicols. 
I had a section cut in this direction from the same specimen, and 
it behaved as expected, save that it showed the cross-hatched 
appearance before alluded to as being noticeable on normal beryl 
so cut. ‘There was no appearance of cleavage. 

The analysis subsequently made confirming the presence of 
beryl, it may be considered certain that this second constituent is 
indeed that mineral. It contains no iolite. 

There is no crystallographic relation discernible in the distri- 
bution of these two chief constituents, orthoclase and beryl. 
Indeed, so far from such being apparent, the felspar seems to 
wander at random through the beryl; branching veins, sharply 
defined and often of extreme fineness, spread over the field. 
Rivers of felspar they look like—now widening into lakes 
and again dwindling to mere streamlets. Scattered through- 
out, the iolite glows with exquisite colour, like many-coloured 
flower blossoms that have fallen and are borne along by a dark 
river. | 

Where broadest these veins are sometimes clouded over—a 
muffed glass appearance—where probably the felspar is kaolinized 
by water action. There is present also, chiefly through the beryl, 
a chloritic mineral most nearly resembling Dana’s prochlorite in 
its habit—ropy, radiating, and vermiform. Some of these radiating 
spheroliths—often extremely minute and closely crowded—show 
the extinction cross with branches remaining along the sections of 
the nicols as the stage is rotated, indicative of a structure radiating 


56 Scientific Proceedings, Royal Dublin Society. 


along the axis of elasticity. Their colour is dark green to yellow. 
They are probably an alteration mineral, occurring principally 
near the surface of the hexagons. To this constituent the dull 
green colour of the crystals seems to be due. A little pyrites and 
hematite are also present. 

The question that now presents itself for consideration is 
this :—Here, in the field of the microscope, are two minerals, both 
in the crystalline state—one true to the external hexagonal form in 
molecular arrangement, while apparently separated into innumer- 
able isolated portions by the second substance, which, in its optical 
behaviour, shows no sympathy with the planes which limit in 
common the extension of both minerals. From our knowledge of 
its nature, it would indeed be altogether anomalous that it should 
show such sympathy. 

Are we to suppose that we are here dealing with a erystal of 
beryl which has been eaten into and replaced, at some period of 
its history, by orthoclase, or with the result of simultaneous inter- 
crystallization of beryl and orthoclase in the first instance ? 

In favour of this last hypothesis it is to be observed that it is 
evidently quite unnecessary to suppose isolation of the beryl really 
to exist, as unnecessary (and indeed obviously more so) as to sup- 
pose, when looking at a map, that there was no connexion between 
the patches of land islanded by the seas. In addition to which, in 
consideration of the evident harmony of orientation of the beryl 
molecules throughout, it is unthinkable. As, then, continuity of 
the hexagonal matrix is in this crystal assured, are we to regard 
the orthoclase as an inclusion merely—that the clustering laminze 
and veins of felspar were formed progressively with the beryl, 
although no crystallographic relation between the two bodies is 
visible, or to be expected—that the phenomenon was due to the 
compelling power or hexagonal virtue of the beryl? 

Now this compelling power is generally effective in a different 
way, or to much less extent. It may, indeed, force an abnormal 
symmetry in a very partial degree on a body crystallizing in juxta- 
position: cases of this are known. It may more commonly com- 
pel into order the molecular confusion outside the parent crystal: 
this may be merely growth, or it may give rise to an envelope of 
smaller crystals of the same species as the parent crystal. It may 
exert itself by taking up a cloud of fragments already formed, and 


Joty—On the Minerals of the Dublin and Wicklow Granite. 57 


give the whole nebula a symmetrical shape as crystallization pro- 
gresses. ‘This is symmetrical inclusion. The inclusions may be 
mixed throughout the crystal in such abundance as to relegate the 
parent crystal to fill the ré/e of a form-producing paste only ; such 
inclusions might form from the magma as the growth of the parent 
erystal progressed. 

But such of these phenomena as are applicable to the present 
case would surely be accompanied by confirmatory optical pheno- 
mena. Will they again serve to explain the simultaneous stoppage 
of growth of felspar and beryl?—those large patches of white ortho- 
clase visible over the surface of the hexagons, but perfectly smooth 
and flush with the prism faces. How did the hexagonal virtue 
extend its influence to the centre of those areas of the monoclinic 
mineral? Within, in the cavities, the felspar crystals suggest an 
independent growth—a growth independent of the hexagonal virtue 
of their matrix. Had the hexagons ceased growing at that stage, 
were abruptly-produced faces out of all relation with the symmetry 
of orthoclase—necessarily so as the laminate crystals are oriented 
in every direction—to be expected? Elsewhere in normal beryl 
the felspar behaves after the general manner of inclusions—pro- 
jects its solid angles out of the beryl, or, if the beryl be sufficiently 
grown, is swallowed up. 

The distribution of the orthoclase in converging veins might 
also be urged against the intercrystallization hypothesis; but there 
is a more direct argument forthcoming. 

It appeared that if the alteration hypothesis was correct, and 
if the seat of the attack was to be sought for at the junction of 
the prism with the orthoclastic matrix, then, in this region, con- 
firmatory phenomena or the reverse might be expected. The con- 
tinuity of prism and orthoclase has already been pointed out. It 
appeared highly probable, on the alteration hypothesis, that this 
junction was the seat of the reaction in the first instance. Sub- 
jected to the influence of a potash felspar in a state of hot solu- 
tion, the beryl was assailed and replaced, it may be at a very slow 
rate. Such replacement may have been of the nature of alteration 
merely, the berylium probably being removed, a re-arrangement 
of the molecules occurring, and the crystalline net of orthoclase 
replacing the original symmetry. 

On these grounds, however vague, I had a section cut from a 

SCIEN. PROC., R.D.S.—VOL. VY. PT. II. F 


58 Scientific Proceedings, Royal Dublin Society. 


well-defined hexagonal prism, close to its junction with the ortho- 
clase, but well within the hexagon, and at right angles to the 
principal axis of the hexagon. 

In this section the phenomena are so eloquent as to set the 
question at rest. The attack is, in a word, seen at a much ad- 
vanced stage. The beryl has broken down completely. Uni- 
formity of extinction, which here, if normal, should be persistent 
between crossed nicols, is no longer seen. Here and there hexa- 
gonal forms, left standing by the invading orthoclase, remain quite 
true to their original position, though veined and worn. These 
behave as amorphous, save for the cross-hatch marks. Other 
hexagonal outlines, with angles projected out of 120°, partially 
restore illumination as they are rotated between the crossed nicols. 
In short, patches of beryl are found, fallen in the fight, and cut 
at such various angles with the optic axis, that they can hardly 
be differentiated by colour or extinction—on the one hand from 
beryl cut at right angles to that axis, and on the other from 
beryl cut along that axis. 

Fig. 2, Plate u. (x 18 diameters), presents a remarkable pic. 
ture of dismemberment and solution. The large, broken, and 
incomplete hexagonal outline there shown was on the alteration 
hypothesis originally a homogeneous portion of the parent crystal. 
It is now girdled round with felspar, and broken up. Its cracks 
are in continuity from side to side. It was even attacked and 
veined by a primary inroad of felspar before the final attack eat 
out a path, severing the primary vein and parting the mass. 
Islands of beryl left standing, or borne down from its banks, 
mark the course of this felspar flood. More than this, so com- 
plete has the final solution been, and so simultaneous all round, 
that movement of the dismembered hexagon after its isolation is 
apparent. Thus it will be seen that the edge a is no longer 
parallel to the edge d. It is, in fact, according to measurement, 
about 14° removed from parallelism. This measurement was 
taken on the photograph; it is then independent of the readings 
of the angles of the hexagon. Placing now the cross wires of the 
microscope along the edge b, and along the edge c, an angle of 
182°, about, is scaled on the section. This is fairly concordant with 
the observation made on the photograph. It should read 134°, to 
agree with it. There is then evidence of movement of the detached 
fragments relatively to each other. 


Joty—On the Minerals of the Dublin and Wicklow Granite. 59 


It will be noticed in this section that tourmaline is present in 
tufts and dark masses encroaching on the edge 5, and generally 
mixed through the felspar. Elsewhere it is conspicuously of 
secondary origin to beryl, and my crystal penetrated by tour- 
maline, before-noticed, is explained by alteration of a similar 
character to this. 

It is to me inconceivable that this jumble of fragments of 
beryl, with molecular orientation in every direction, scattered 
through a sea of felspar, owes its external hexagonal form to the 
hexagonal virtue of the beryl. If, in short, the beryl was not 
able to keep itself in order, how, on the intercrystallization 
hypothesis, was it able to shape into order, against their normal 
molecular tendencies, the molecules of felspar P 

What were the nature and circumstances of the reaction which 
led to this alteration or substitution? Was it hydro-igneous or 
simply igneous ? 

It seems probable, in the first place, that intermixtures like 
this of bodies of very different melting points is most readily ex- 
plained by hydro-igneous formation of one or both the bodies. 
Thus Daubré, by attack with steam at 400°C., obtained crystals 
of quartz and pyroxene imbedded in an easily fusible matrix, 
derived from the glass tubes employed. 

Other arguments for low temperature origin of the felspar 
exist. ‘Thus we find a beryl moulded round by felspar: the edges 
of the beryl are sharp and well defined, although its melting point 
is far below that of orthoclase. 

Again we find the beryl coloured yellow, green, or blue, but it 
loses all colour, according to experiment, at 350° C., after an hour’s 
heating. 

There is internal evidence too. Hxamined with high powers 
the sections reveal innumerable enclosures. Some glass, but some 
composed of liquid, with movable gas bubble. These are plenti- 
ful, both in beryl and felspar. In places they range in veins and 
strings, resembling fluxion structure. Tiny crystals (?) accom- 
pany in shoals. With inclined microscope the gas bubbles may 
often be induced, on tapping the stage, to travel from end to end 
of the cavity. 

It seems probable, then, that the change experienced by these 
beryls was effected at low temperature, or hydro-igneously. The 

F 2 


60 Scientific Proceedings, Royal Dublin Society. 


pseudomorphous nature of that change is sufficiently accounted 
for by supposing the reaction as engaging with the beryl only, 
not with the tourmaline matrix. 

In speculating on the circumstances attendant on, and which 
led to, the reaction, I may be pardoned perhaps for venturing to 
suggest a theory of the formation of beryl and tourmaline through- 
out the granite. 

The remarkably local nature of the distribution of the beryl in 
the granite is well known. ‘There are no crystals worth mention- 
ing in the quarries situated close above those in which this abun- 
dance of beryl is found. Rochetown Hill is mentioned by Weaver, 
writing in 1819, as affording beautiful specimens. I searched the 
quarries recently. The mineral is worked out. I found but one small 
specimen. In a similar way the Killiney quarries have ceased to 
yield; they are now represented by Kingstown Pier, where speci- 
mens may be found imbedded in the blocks used in its construc- 
tion. At Ballybetagh a mere opening on the surface yielded a 
group of crystals contained in a vein of porphyritic granite, which, 
pursued further down, ceased to yield. The habitat of beryl is in 
short the pocket or the vein, and, when the vein, generally close to 
the surface. 

In all these respects it resembles that other accidental mineral 
of the granite, tourmaline. 

Nowit is most thinkable to suppose the rare elements plucintin 
and boron originally diffused more or less uniformly throughout 
the region, in which we will suppose the elements of granite to 
be in a state of slow progressive crystallization in presence of 
_ water. 

As cooling and solidification advanced, a concentration of those 
elements would occur, which failed to take part in the molecular 
arrangements going on throughout the magma, and pockets of 
highly concentrated mother liquor would be formed. 

Many of these pockets, imprisoned at great depths, would re- 
tain their position till loss of heat enabled, first, beryl, and then 
tourmaline, to crystallize out. 

Many of these pockets again, as solidification advanced, may 
be conceived as pressed out, and uniting in one outflow, forcing 
their way to the surface in cracks left by the shrinking rock; 
only crystallizing when from loss of pressure, or by conductivity to 


Joty—On the Minerals of the Dublin and Wicklow Granite. 61 


the upper and cooler layers of rock, they have attained a suf- 
ficiently low temperature. 

In these veins the erystals of beryl, forming in deeper and 
hotter regions than the tourmaline, and taking toll from the pass- 
ing waters, grow and gather in bunches; the zone of solidification 
retreating downwards as cooling progresses. Similarly, tourmaline, 
forming always higher in the vein than beryl, but, like it, ever 
forming deeper and deeper in the granite, covers up finally with 
a schorlifferous covering the beryl already deposited. 

These beryl and schorl veins may be seen in perfection at 
Glencullen. Sometimes they are euritic in texture: more gene- 
rally porphyritic, when they yield beryl and schorl, intermingled 
with overgrown crystals of felspar. 

If it is allowable to reason on these lines, it is perhaps sufficient 
to seek for the cause of the alteration experienced by the beryls in 
a change of temperature, it may be, of the upwelling waters, where- 
by dissolution and replacement of the beryl was brought about; or 
it may be in a change of constituents—more highly alkaline water. 
Or, finally, both causes may have operated. 

Those other changes—cavities eaten out, chlorite developed 
near the surface of the crystals, kaolinizing of orthoclase and 
beryl—are most probably changes of tertiary formation. It is 
probable that water action, at the ordinary temperature, has 
effected some of these changes. Thus the most advanced cases of 
decomposition have been taken from the wettest veins in the 
quarry. JI have, from these veins, removed hexagonal shapes, 
which, crushed between the fingers, crumbled into a rusty-brown 
kaolin. 


Percentage Composition of the altered Beryls. 


It is interesting to note the extent to which replacement by 
orthoclase is carried in some cases. This may be investigated in 
three ways: by specific gravities, by specific heats, and by chemical 
analysis. 

1. The specific gravity of beryl from Glencullen was found to 
be 2:722 ; the specific gravity of orthoclase from Glencullen, 2-510. 
The specific gravity of the mixed minerals was, in the specimen 
dealt with, 2-625. The weight of this specimen was 50-400 grams, 


62 Scientific Proceedings, Royal Dublin Society. 


Neglecting the influence of the small quantity of iolite present, 
and also the influence of the chloritic mineral, this gives a percen- 
tage composition— 

beryl. 5 . O44 

Orthoclase, . . 45:6 


2. It is evident from the figures previously given that the 
specific heats will not enable a direct percentage estimation to be 
made. Thus the specific heat of Glencullen beryl was found to be 
0:2140; of the mixed crystal (the same used in investigation by 
specific gravity), 0°2156; while the following results were obtained 
for Glencullen orthoclase :— 


OV ee GED 
CONE aed a er eROTG 


giving a mean of 0:1979. Hence, a specific heat lower, and not 
one higher, than that of beryl was to be expected. In fact, calceu- 
lating it in the percentages obtained above by specific gravity, the 
specific heat of such a mixture would be about 0:207. It is re- 
markable that the large percentage of water (1:4) revealed in the 
analysis of this specimen will just account for the discrepancy. 
Beryl normally contains no water, and this orthoclase, by Gal- 
braith’s analyses, 0°58 per cent. only. Assuming this as high as 
0-3 per cent. of the whole, an abnormal quantity of water, equal to 
over one per cent., is present. ‘Taking it as low as one per cent., 
and re-calculating, the theoretical specific heat is found to he 
0-2150. 

3. According to microscopical examination, orthoclase is the only 
mineral present which is known to contain an appreciable amount 
of potash. Analysis shows that there is 5:11 per cent. of K,O in 
the mixed mineral, the same specimen being used that had served 
for the previous investigations. Now, as the result of Prof. 
Galbraith’s seven analyses,’ the felspar of this granite contains 
12-2 per cent. of potash. On these data we find orthoclase 42 per 
cent. 

If, however, we calculate the percentage of beryl by the per- 
centage of BeO given below, and by the result of Mallet’s analysis 
of Killiney beryl (he obtained 13-09 per cent of BeO—Dana), so 


1 Journal of the Geological Society of Ireland, vol. vi., p. 226, 


Joty—On the Minerals of the Dublin and Wicklow Granite. 63 


much as 74 per cent. of beryl is obtained. This suggests that 
only a small quantity of the oxide was removed in the process of 
alteration. If we assume 58 per cent. of beryl present, then, on 
_ Mallet’s analysis, 7-59 per cent. of BeO is to be expected, leaving 
2°16 per cent. of that body “free” or mixed through the ortho- 
clase to the extent of 5 per cent. of its weight. 

It is also open for us to assume that the deficiency from the 
normal percentage of BeO for the entire mass is due to weathering 
only; that, in short, none of the oxide was removed by the primary 
alteration ; but that the subsequent weathering of the beryl con- 
stituent into kaolin and the formation of a chloritic mineral are 
alone accountable. On this hypothesis the orthoclase would con- 
tain about 13 per cent. of BeO. We are, indeed, driven to suppose 
that. alteration had the effect of reducing the percentage of BeO, 
at all events in some degree; for the examination of these crystals 
goes to show that it is the beryl constituent which is most readily 
kaolinized or replaced by chlorite; and the analyses of kaolinized 
beryl (Dana’s min.) reveal a diminution or nearly complete re- 
moval of glucina. 

The question, however, obviously cannot be discussed on the 
results of one analysis only. 


Analysis of altered Beryl. 


Sp. gr., 2°625. 
810, : , : : 57°73 
Al,O; : : : : 20:06 
Fe,0, ‘ ‘ ‘ : 4°56 
K,O “he : : 5:11 
Na,O ; : oN 64 
BeO : . : : 9°75 
MnO ‘ i ‘ trace 
MgO ‘ : : trace 
CaO : s : ; trace 
Ignition (H,0) : 1-44 


100°29 


1 Made with Mr, W. Harly’s kind assistance, and chiefly under his directions. 


64 Scientific Proceedings, Royal Dublin Society. 


The glucinum, along with some of the iron, was separated from 
the alumina by carbonate of ammonia, subsequently precipitated 
by ammonia, and weighed as the oxide along with some iron, which 
was then estimated volumetrically. 

This sample of mixed beryl and orthoclase may then be consi- 
dered, with little doubt, as containing some 42 per cent. of the latter 
mineral, and originally some 58 per cent. of beryl. The percentage 
composition of four other crystals, all showing well-marked hexa- 
gonal faces, was also investigated by taking specific gravities. 


1. White homogeneous crystal, with beryl lustre. Very hard 
all over surface. 


Weight, 24'803. Sp. gr., 2°69. 


Beryl, : av 486 
Orthoclase, . dle 


2. Same appearance as 1. 
Weight, 9°764. Sp. gr., 2°67. 


Beryl, eae 
Orthoclase, = 1 Oe. 


3. Piebald crystal. Heterogeneous appearance. 
Weight, 20°554. Sp. gr., 2°59. 


Beryl, . =) 39 
Orthoclase, 5 oe 


4. Same appearance as 3. 
Weight, 21:152. Sp. gr., 2.57. 


Beryl, : oO 
Orthoclase, 3 OTE 


These computations assume the specific gravity of beryl as 
2°722 ; of orthoclase as 2°510. It is to be remembered that other 
values are assignable, but that these seem fairly well borne out by 
the analysis. 


JoLty—On the Minerals of the Dublin and Wicklow Granite. 65 


Briefly summing up the results of these various observations, 
it appears, with great probability, that the heterogeneous crystals 
were primarily composed entirely of beryl: subjected secondarily 
to reaction with a potash felspar in a state of hot solution, they 
were partially replaced, and that to very different degrees; that 
the primal seat of this reaction is, in general, traceable to one 
region of the crystal, now the implanted surface, in which direction 
the replacement is most complete, the original structure of the 
crystal being often completely broken down; and that this reac- 
tion, being confined between beryl and felspar, allowed of the 
hexagonal form being preserved within the schorlifferous matrix, 
the result being a variable mixture of felspar and beryl pseudo- 
morphous after beryl. The felspar so mixed with the beryl is 
orthoclase, containing a mineral in general foreign to Ivish rocks, 
iolite, and, further, containing, there is reason to believe, glu- 
cina; but this question is not gone into in the present Paper. 

Subsequently, and probably as the effects of hydration, the 
mixture has been kaolinized to variable extents; and, asa tertiary 
alteration also, a chloritic mineral has been formed through the 
beryl. 

The beryls of Glencullen often radiate in beautiful conical 
bunches, with a completeness and regularity not noticed in de- 
seriptive mineralogy. 

These are often of delicate green and yellow hues; and such, 
in common with crystals of normal habit, lose nearly all colour 


after being exposed for a short time to a temperature of about 
350° C. 


The Iolite of Glencullen. 


I now turn to the consideration of the very minute crystals 
developed through the felspar, and absent from those portions of 
the sections composed of beryl. 

The crystals appeared in two types :—a wide polygonal form, 
often with twelve edges, extinguishing along two edges situated at 
right angles to each other on the polygon; a rectangular elon- 
gated form, extinguishing most generally along the edges, but 
often at variable angles with the edges. oliation in thin plates 


66 Scientific Proceedings, Royal Dublin Society. 


was common over the surface of the polygonal form: cleavage was 
generally parallel to the ends of the rectangle in the rectangular 
forms. 

On first approaching the subject, I formed the hypothesis that 
some of the symmetrically extinguishing rectangular forms were 
beryl cut parallel to axis of prism. The absence of hexagonal 
sections threw doubts on that hypothesis. Some of the other 
rectangular forms I thought were orthoclase developed on the 
zone ph’ (Levy). Such a zone shows large base, rectangular, 
with extinctions parallel to sides; orthopinacoid large, with extine- 
tions parallel to sides; clinopinacoid small, with extinctions paral- 
lel to sides in ‘‘orthose non-deformé,” at 5° in “orthose deforme.”’ 
But this zone should show, when cut squarely, the axial angle of 
63° 33’. It was never found thus in the sections. The colours 
of polarization, too, were not those of orthoclase. 

It was evidently possible, also, to account for the appearances 
by supposing the crystals orthorhombic, in which case, further, 
both forms might be supposed to be different views of one and the 
same crystal. 

Now the angles of the polygon were all about 150° when 
twelve-sided ; and in eight-sided figures, not uncommon, one set of 
faces produced intersected at 90°, another at 60° and 120°. To 
what orthorhombic mineral were such angles to be assigned? Not 
being acquainted with any such, I had set the mineral for the most 
part down as “doubtful,” with the suggestion that some of the 
forms might be orthoclase, when I had recourse to an apparatus I 
devised about this time for investigating the melting points of 
small fragments of minerals. This apparatus is briefly described 
in Nature (vol. xxxiii., p. 15), where I call it a “meldometer,” or 
measurer of melting points. By the help of this apparatus I 
differentiated them from every substance I had ever suspected as 
being present. I must explain, however, how I succeeded in 
obtaining the crystals isolated and free of the matrix. 

I mentioned before the cavities eaten by decomposition in the 
large hexagonal crystals of mixed beryl and orthoclase. These 
cavities appeared filled in part with a rusty-brown powder, and in 
part with a frail skeleton of hard matter (felspar) clinging to the 
walls or loose in the cavity. On removing this debris, crushing 


Joty—On the Minerals of the Dublin and Wicklow Granite. 67 


the lumpy parts, washing and cleaning in boiling hydrochloric 
acid, clear, glassy crystals, of extremely small size, appeared 
in countless numbers through the residue. These, mounted in 
Canada balsam, proved to be the identical crystals visible in the 
sectlons—some beautifully sharp and clear, some partly decomposed 
and overspread with a filiform, branching growth of olive-yellow 
colour. Micrometric measurements gave 0:1 mm. as the length of 
the larger specimens showing good angles. With such dimensions 
it was difficult to deal with them singly. 

Again, by breaking up the hexagons and crushing the felspa- 
thic matrix containing these crystals, treating carefully with 
hydrofluoric acid, specimens were obtained fairly clean. But the 
first source, where decomposition had removed the beryl and some 
of the orthoclase, but had spared the small sharp crystals, was my 
great source of supply. In these hollows slow-acting decomposi- 
tion has effected a fairly perfect isolation, and I have opened cavi- 
ties from which the tiny crystals could be poured in great numbers, 
only requiring cleansing from their rust-coloured coating to be 
ready for the microscope. 

The slides composed of these crystals present a spectacle of such 
perfection of form, and, in the polariscope, such richness of colour, 
as would far surpass any power of description. Feeling this, I will, 
instead, refer the imagination of my reader to the soft crimsons, 
purples, and tender blues of those cloud islands and vistas seen at 
sunset, where the colour is not the dead brightness of opaque 
reflection, but is living with transmitted light. And I would 
remind him, that while in that case the imagination is affected. by 
the far-off peace of those regions to clothe them with an unreal 
richness and tenderness of tint, these children of the rocks are not 
so seen with the eyes of dreamland. I will ask him, then, to pic- 
ture a precision of form and matchless depth of colour which, to 
none but the scientific imagination, are as breathless objects of 
adoration, as the infinite oceans of sunset. 

Having obtained the mineral thus isolated from its matrix, it 
was resolved to treat some of the little crystals on the meldometer 
along with orthoclase, and also compare their behaviour at high 
temperatures with topaz, quartz, &c. I had only just begun to 
use the apparatus, and was desirous of testing its value as a means 
of differentiation ; for although no determinations of melting points 


68 Scientific Proceedings, Royal Dublin Society. 


were obtainable to render numerical results of value, yet the com- 
parative test was easily applied, and would probably throw some 
light on the nature of the mineral. 

Comparison with Orthoclase.—The orthoclase used was from 
Belleek, and also from Co. Dublin ; respectively red and white in 
colour—subtranslucent. The unknown crystals were transparent 
and colourless. 

The orthoclase fused first, and gathered into transparent beads 
of glass containing large bubbles. At a much higher temperature 
the unknown mineral rounded and turned milk-white in colour, 
developing no bubbles. 7 

The experiment was more than once repeated. The unknown 
mineral had evidently a much higher melting point than orthoclase, 
and its behaviour in other respects, also, differentiated the two 
substances decisively. 

Comparison with Topas.—Fragments of clear topaz and the - 
unknown mineral. Both rounded simultaneously, and both turned 
milk-white. The topaz, however, emitted a gas which raised 
blisters and blue bubbles on the melting surface of the fragments. 
On the breaking of these bubbles, threads of glass were thrown 
about the hob, and the gas attacking the platinum deposited rings 
of colour around. Probably the gas contained in these bubbles is 
fluorine, liberated at the high temperature employed. The coloured 
rings, fluoride of platinum. No such phenomena occurred with 
the unknown mineral. They probably contained no fluorine. 

Comparison with Quartz.—Clear rock crystal showed a much 
greater resistance to the temperature of the hob, only fusing at 
the extreme limit of endurance of the platinum itself. 

The melting point of the unknown mineral was therefore fixed 
as above that of orthoclase, and below that of quartz. » 

These results, together with the knowledge of its angles already 
gathered from the microscope, led me to think for a time that I 
might be dealing with a new species. More accurate crystallo- 
graphic measurements were desirable. 

By manipulating one solitary crystal, obtaining extinctions 
along its faces, and measuring its angles, its orthorhombic charac- 
ter, both by symmetry and elasticity, was determined beyond doubt. 

Its specific gravity was now taken by Professor Sollas’ method. 
It was found to be 2°58. 


To face page 60.) 


ID) LO} Tal 18 © ILI, 


ORTHORHOMBIC. 


TA T=119° 10’ and 60° 50’ 
TA i-3 =150° i Ai-3 = 150° 25° 


i-3 A i-3 = 120° 50’ = ON T= 90° 


Cleavage, 1-7 distinct ; 7-2 and O indistinct. 


Crystals, foliated parallel with 0. Twins, composition face J. 


Transparent. 
Dichroic, blue to yellow, but feeble in small crystals. 


Lustre vitreous. 
Colour, blue shades. 


Spec. grav. = 2°59 
Hardness = 7-775 


Fuses at 5:5, loses transparency. 


Chemical Composition (Mean). 


Silica, SiOz, 50-0 
Alumina, Al20s, 31:6 
Ferrous Oxide, FeO, . 6°6 
Magnesia, MgO, 10-4 
Calcium Oxide, CaO, 0-6 
Manganese Oxide, MnO, 0-4 
Tegnition, (H,0), 1-4 


Fracture, sub-conchoidal. 


LO eae ORD Shi Rt mB. 


ORTHORHOMBIC. 


v 
5. 


Fig. 4. Fig. 6. 


Fig. 5. 


Transparent. 


Dichroism uncertain. 


Lustre vitreous. 


Colour, pale blue. 
Spec. gray. = 2°58 


Hardness about 7. 
Fuses with Iolite, turns opaque white. 


Analysis of Impure Specimen. 

56°7 

20°7 

13-9 

4:2 
trace 

trace 

2°0 


97°5 


To face page 69.) 


ORTHOREH 


| 


I \ T= 119° 10' and € 

IA i-3 = 150? it 

i-3 A i-3 = 120° 50’ 
Cleavage, i-% distinct ; i-7 and O indis} 


Crystals, foliated parallel with O. 


Transpar¢ 


Dichroic, blue to yellow, but 


Lustre vitr 
Colour, blue 


Spec. grav. : 


Hardness = 
Fuses at 5:5, loses 


Chemical Compos: 
Silica, S102, 
Alumina, Al2.0s, 
Ferrous Oxide, FeO, . 
Magnesia, MgO, 
Calcium Oxide, CaO, 
Manganese Oxide, MnO, 
Tenition, (H20), 


JotY—On the Minerals of the Dublin and Wicklow Granite. 69 


The characteristics ultimately determined are recorded in the 
annexed Table, in the right-hand column. The characteristics 
of Iolite, the Cordierite of the French school, appear in the left. 
Taken collectively the evidence is, I think, irresistible that these 
small crystals are iolite. 

Figure 1 on the Table, right-hand column, depicts the basal 
face of the crystal. It shows foliated habit and twin-line, or trace | 
of composition plane J. 

The angles I had in the first instance determined as the mean 
of many measurements were so close to 150° each, that I decided 
to enter them as such. This gives nearly the same values as Dana 
and others record: J A Tis 120° and 60°, and the secondary face 
in the zone 11 becomes nearly i — 3. 

Extinction is along 7-7 and ¢ — #, shown by the arrow- ner 
The face i — 3 is often absent, and always small. Fractured corners, 
as in fig. 1, are common. ‘The cleavage is then well seen. 

Figure 2 is elevation of zone 11. Extinction, as shown. 

Figure 3 is section on ¢ — 2, showing cleavage. 

Figure 4 is end-elevation of zone 11. 

Figure 5 is section oni - %. Cleavage very obscure, or absent. 

Figure 6 is a hemihedral form respecting i - 3; not very un- 
common. 

Looking down the column, I need only observe that the colour 
is only seen when a large number of crystals are superimposed, as 
in a narrow test-tube, and viewed by transmitted light. 

The hardness was only very approximately determined by press- 
ing a number of the crystals into the end of a lead wire, and then, 
using the wire as a handle, proceeding as usual. 

The fusibility was determined to be about the same as iolite 
by comparison with an authenticated specimen on the meldometer. 
It is perhaps a little higher than that of the specimen used; nor 
did the known iolite whiten to any great extent. The loss of 
transparency experienced by iolite on fusing is however well known. 
Lime is generally present in this mineral: its absence might 
account for exceptional behaviour in this respect. 

An analysis, made with Mr. Harly’s assistance, is added. The 
material for this was obtained as follows:—The powder obtained 
from the hollows in the hexagons was boiled for a few minutes 
in strong hydrochloric acid, and thoroughly washed in water: 


70 Scientific Proceedings, Royal Dublin Society. 


separated from free quartz, orthoclase, and tourmaline, by Thoulet’s 
specific gravity solution. The crystals thus obtained were freed of | 
large mixed fragments and very fine particles by descent through 
a long column of still water ;—a method described by me elsewhere 
(Proc. R. D. S., vol. iv., p. 291). The large rough fragments so 
removed were found on microscopic examination to be very im- 
pure, the medium-sized crystals fairly pure, the fine dust very 
heterogeneous and impure. A few of the larger of the medium- 
sized crystals being sorted out for photographing and mounting, the 
remainder, weighing about two decigrammes, was devoted to 
analysis. 

The percentages obtained in the analysis hardly approximate 
to the numbers for iolite given in the left-hand column. This was 
to be expected from the impurity of the sample. The presence of 
4 per cent. of MgO is, however, important, as there was probably 
no source of impurity present capable of affording an appreciable 
weight of that body. I think it highly probable that glucina may 
enter into the composition of these crystals, replacing the magnesia, 
the elements Be and Mg being isomorphous. Glucina was not 
looked for in the analysis. J¢ is remarkable that these crystals 
seem present only in orthoclase, thus imtermixed with beryl. In 
other sections of Glencullen orthoclase, as well as in sections of 
granite! from Co. Cavan, Co. Mayo, Newry, Killiney, Warrenpoint, 
and from the Mourne Mountains, I could detect none of these 
crystals. As in the case of their felspathic matrix, I have little 
doubt of the correctness of my diagnosis of the mineral species. 
Whether perfectly normal in chemical composition or not, can 
however only be decided by further and more careful analysis. 

The formula to be deduced from the analysis, such as it is, is— 


10 SiO, .2(Al,0,. FeO). MgO . H,0, 


which, be it observed, affords a bisilicate oxygen ratio, instead of a 
unisilicate ratio. 

As a microscopical mineral, this iolite will be recognized by its 
basal angles of 150°, 120°, or 60°; its generally symmetrical extinc- 
tion on elongated rectangular sections, and the transverse cleavage 
on such sections. ‘he foliation, or plating on O, and the oblique 


1 Kindly lent by Professor Hull. 


Joux—On the Minerals of the Dublin and Wicklow Granite. 71 


twining line parallel to Z, are also frequently met with. Occa- 
sionally the crystals occur in radiating groups. When thus 
arranged, it will be found that the basal faces have a sort of 
symmetrical arrangement, being all oriented into planes perpen- 
dicular to the plane of radiation, so that it is seen as radiating in 
rectangular forms only. I may also observe, that so minute are 
these crystals that they are freely contained and propped into 
every conceivable position within the small thickness of the section. 
This fact, coupled with the simultaneous focus of pinacoid, or 
prism faces, on opposite sides of the plane of symmetry, renders 
necessary considerable caution in deciding on the nature of the 
forms in the field. 

The angles are generajly sharp. Enclosures are rare ; generally 
glass. Mutual interpenetration is very common. They present all 
the appearance of having been formed antecedently to their felspa- 
thic matrix. Colours are generally exquisite, but they will, of 
course, vary with the thickness of the section in the field. Pale- 
grey forms are not therefore to be put down necessarily as felspar— 
they are not uncommon. ‘The dichroism is too feeble, seemingly, 
in such small crystals to be of value in diagnosis. Branching 
veins of a translucent greenish decomposition product cover the 
faces in some cases. Iolite is known in many decomposition 
forms. 

Figure 4, plate u1., is a photograph showing a group of iolite 
crystals sorted from those prepared for analysis, as described. ‘They 
are exceptionally large specimens. Enlargement, 18 diameters. 

Figure 3, plate 111., more highly magnified (x 70 diameters), 
shows iolite in situ. A polygonal form, slightly turned up, so as 
to show the faces i - iand J conspicuously, as well as the basal face 
O, occupies the centre of the field. The other forms are mostly 
rectangular, parallel, more or less, to the face i - 7. Some of these 
show the i—% cleavage. They nearly all extinguish longitudinally. 
The chequered appearance of the felspar is displayed over the 
field. 


veo 


EXPLANATION OF PLATES ILI., IIL, anv IV. 


Prats II. 


Figure 1.—Veins of Felspar traversing Beryl. Section through a crystal 
of altered Beryl, parallel to axis of hexagonal prism. 
Light polarized. (x 18 diameters.) 
Figure 2.—Broken down Beryl. Section ifear base of mixed Beryl and 
Orthoclase. Light polarized. (x 18 diameters.) 
N.B.—As the letters have been omitted, the edges 
referred to may be identified thus :—lowest left-hand 
edge (about one centimetre in length) is the edge d; 
the adjoming edges c; the uppermost edge broken by 
the fissure is b, and the next adjoining edge is a. 


Puare III. 


Figure 8.—lolite im situ, showing markings of Orthoclase. Section in 
altered Beryl. 

Figure 4.—Group of Iolite crystals removed from cavities in mixed 
Beryl and Orthoclase. Light polarized. (x 18 dia- 
meters.) 

N.B.—The description of these two last figures has 
been transposed on the Plate. 


Puate LV. 


Figure 5.—Radiating Beryl in granite matrix. 


ted 


IX.—NOTE ON THE ARTIFICIAL DEPOSITION OF CRYSTALS 
OF CALCITE ON SPICULES OF A CALCI-SPONGE. By 
PROFESSOR SOLLAS, D.Sc. 


[Read, June 15, 1885.] 


Some acerate and triradiate spicules of a calci-sponge, after having 
been left to stand for some days in water containing an excess of 
calcium carbonate, were found to have become incrusted with an 
abundant crop of minute crystals of calcite. The exact form of 
the crystals was not ascertained; but, as on rotation between 
crossed Nicols, they extinguished simultaneously with the spicules 
on which they were seated, and underwent the same changes in 
refractive index, we may conclude that the optic axes of the cal- 
cite forming a spicule, and the crystals incrusting it, are similarly 
orientated. 

A curious feature in the distribution of the crystals is worth 
notice. ‘They do not cover the whole of a sagittal triradiate, but 
are confined to opposite sides of the paired rays and the extremity 
of the unpaired ray; an acerate, is, however, often covered with 
them for its whole length, but usually only on opposite sides. 
Thus the crystals are deposited only on those regions which show 
the greatest liability to solution:' thus it would appear that the 
polarity which leads to solution also determines deposition. 


1 Vide Sollas, on ‘‘ Physical Characters of Calcareous Spicules,”’ &c., Proceedings 
Royal Dublin Society, vol. iv., N.S., p. 385. 


SCIEN. PROC., R.D.S.—VOL, V. PY. II. G 


Ee A 


X.—THE DOUBLE QUADRIFORM LIGHTHOUSE LAMP. 
By PROFESSOR W. F. BARRETT. 


[Read, December 16, 1886. ] 


Ir may be of interest to lay before the Members of this Section of 
the Royal Dublin Society some observations which I have recently 
had the opportunity of making upon the fog-penetrating power of 
the new system of lighthouse illumination devised by Mr. J. RB. 
Wigham, of Dublin. 

As Professor Tyndall has remarked in a recent letter to The 
Times, when Mr. Wigham began his experiments the best light- 
house lamp in general use was the four-wick oil-lamp, and the 
augmented illuminating power in lighthouses which exists at the 
present day is very largely due to the competition which Mr. 
Wigham’s superior light has called forth. As is well known, 
Mr. Wigham is the inventor of gas illumination for lighthouses, 
and the adaptability of gas for this purpose has enabled him to 
build up a series of three, four, and now eight lights, with their 
appropriate lenses, within one lighthouse. The high temperature 
within the lantern produced by so many lights has not, I under- 
stand, in any of the trials made in Ireland, been found to be dan- 
gerous to the lenses, and whilst a high temperature is favourable 
to the illuminating power of coal-gas, it would, I imagine, be fatal 
to the employment of mineral oils instead of gas. ‘The latest and 
most powerful arrangement which Mr. Wigham has made is the 
so-called Double Quadriform light (figs. 1 and 2). This consists 
of four superposed 88-jet gas-burners (B.B., &c.) placed alongside 
of four similar superposed sets, the eight lights being in one plane: 
parallel to this plane, and at the proper focal distance, are placed 
eight annular lenses on one side, and eight similar lenses on the other 
side of the gas-burners. Over each of the burners a chimney is fixed ; 
these lead into a central flue, C, so arranged that no appreciable 
interference with the light is produced. The recent experiments 
made at South Foreland show that similar superposed lights blend 
into one within 1500 feet from the lighthouse ; and when this occurs 


(43) 


Barret1—On the Double Quadriform Lighthouse Lamp. 


GENERAL VIEW‘ )F APPARATUS. 


SEcTION THROUGH FocaL PLANE. 


Scale—+ inch to a foot. 


G 2 


76 Scientific Proceedings, Royal Dublin Society. 


a beam of eight-fold the intensity of a single light is obtained 
from the Double Quadriform.' An ingenious contrivance allows 
the whole arrangement to be rotated without disturbing the gas 
supply ; thus the entire horizon can be successively illuminated with 
a beam of light of surpassing power. 

The Commissioners of Irish Lights have for some months past 
been testing this new Double Quadriform light, which they have 
had erected in an experimental house at Howth Head, some 100 

.yards distant from the Bailey lighthouse, the well-known powerful 
first-order light at the entrance to Dublin Bay. The Bailey, it 
may be mentioned, is also a gas lighthouse that can, by the addition 
of concentric rings of burners, be rapidly raised when fog prevails 
from 28 to 48, 68, 88, or 108 jets. Alongside the Bailey light is a 
powerful siren trumpet, driven by a gas-engine, and blown by com- 
pressed air at minute intervals during heavy fogs. 

It so happened that on both the evenings when I had arranged 
to observe the new light a fog had settled over the Bay of Dublin. 
My position of observation was near my own house at Monkstown, 
where, in clear weather, an uninterrupted view over the bay can be 
obtained, my standpoint being distant six miles, as the crow flies, 
from the experimental lighthouse. 

Evening of November 18.—Owing to the intervening fog no 
trace of the Bailey light could be seen, though its position was 
well known. The first experiment was the trial of a series of gas- 
jets fed with ‘“albo-carbon” vapour and oxygen, placed in the 
focus of a first-order annular lens, such as is used for revolving 
lights. Brilliant as was the light so produced, it was completely 
cut off by the fog before it reached me, though the beam was di- 
rected on to the position I occupied. With a large opera glass I 
was however just able to make out the light, and saw also the 
Bailey near it, as a fainter speck of light. Suddenly, at the pre- 
arranged time, a clear well-defined pillar of light sprung into view, 
easily visible to the naked eye, and appearing as a large distinct light 
through the glass. This was the Double Quadriform. In ten 
minutes, as had been arranged, that was extinguished: complete 
darkness again covered the horizon. With great difficulty, and 


1 The South Foreland experiments were made with a light of half this power. 


Barrett—On the Double Quadriform Lighthouse Lamp. 77 


only by the aid of an opera glass, the Bailey light was occasionally 
found. 

After another interval the Double Quadriform was again 
lighted, and this time made torevolve. As before, it was a striking 
object to the naked eye, arresting the attention at once, and the 
period of its revolution was easily noted by the unaided eye. 

Evening of November 23.—This night the experiments were 
repeated under still more crucial conditions. A much thicker fog, 
with drizzling rain, hid all lights from view except those near at 
hand. ven the two fine lights at the “‘ Poolbeg,” one of them a 
first-order revolving oil light, were completely obscured, though 
these lights were less than half the distance of the experimental 
light. ‘The Bailey hght itself was entirely cut off, and could not be 
picked up even with a powerful glass. It was then burning, as I 
learnt next day, its maximum light of 108 jets. Not the faintest 
trace of the fog siren at the Bailey could be heard, though, as after- 
wards ascertained, it was sounding with its full power during these 
experiments. Precisely at the time appointed for the lighting up 
of the Double Quadriform a sudden glare was seen on the horizon. 
With the opera glass the shape of the light was easily defined, but - 
no trace of the adjacent Bailey light could be found, even after the 
most careful search through the glass. There were in all 632 gas-jets 
burning, and as these, by prearrangement, were raised and lowered, 
a flashing light was produced readily seen by the naked eye. The 
double triform arrangement was next tried: this could be seen 
faintly with the naked eye. ‘The biform was now tried, but this 
was invisible even with the glass. This is important as showing 
the advantage of the multiple lights; for, in this experiment, the 
character of the lights and lenses were the same as the double 
quadriform, only of one-fourth the total power. The double 
quadriform was again put on, and, as before, its glare was at once 
seen and its position determined with the naked eye, the exact 
quadrangular shape of the light being easily made out with the 
glass. All the other lights remained utterly invisible, even with 
the aid of a good glass and a knowledge of their exact position. 

I cannot but think that the facts here recorded are worthy of 
attention. ‘They demonstrate that the double quadriform arrests 
the attention, as a conspicuous glare to the naked eye, and as 
a clearly-defined object in an opera glass, through a fog of suf- 


78 Scientific Proceedings, Royal Dublin Society. 


ficient depth and density to cut off a first-class light shining through 
an annular lens at half the distance, and to quench the sound of a 
fog-siren adjacent. to the double quadriform. 

Tt would have been important to have made a comparative 
experiment with a single electric light of similar intensity, having 
its beam concentrated by a single annular lens. There were, 
however, no means of trying this. ‘The recent elaborate Board 
of Trade investigation at South Foreland led the eminent men 
of science who conducted the inquiry to the conclusion that the 
electric light has a slightly greater penetrative power in fog than 
the triform oil or quadriform gas-lamp with which it was com- 
pared, the two latter being practically equal, light for light, in all 
conditions of weather.' 

Nevertheless, it is much to be desired that some representa- 
tives of the Trinity Board, or of the Board of Trade, should, 
whilst the double quadriform is in its present position, come over 
to Dublin, and in foggy weather test a gas-light twice as powerful . 
as any they have yet tried, and under conditions exactly similar 
to those which prevail in the practical use of the light at sea. 

No doubt, the cost of the double quadriform light is consider- 
able, both as regards initial expense and consumption of gas. On 
the other hand, it must be borne in mind that a powerful light of 
this kind is only intended for the more important points on the 
Coast, and it is only under exceptional conditions of fog that 
the full consumption of gas need be resorted to. Moreover, as 
Mr. Howard Grubb, F.R.S. (who, independently of myself, has 
recently tested this new light), has remarked in his Report :— 
“ Heonomic considerations fade into insignificance before the one 
broad fact that, when occasion does require a powerful light, this 
arrangement of Mr. Wigham’s gives the power of producing a 
revolving light unequalled by any existing arrangement.” 


! These conclusions, however, seem to be contradicted by, at any rate, one observer 
(p. 29 of the Report), who, after comparing the lights in ‘‘ drizzling rain and dense 
fog,’”’ remarks: ‘‘In honesty, I award B [that is, the quadiform gas], the most points, 
for I consider it the best light from first to last.”’ 


Deacon 


XI.—ON A CLOGG ALMANACK IN THE SCIENCE AND ART 
MUSEUM, DUBLIN. By BENJAMIN H. MULLEN, 
B.A., Dus. (Puate V.) 


[ Read, December 16, 1885. ] 


For many years past this Clogg has been in the Museum, and my 
attention was first drawn to it by Mr. T. H. Longfield, who had 
seen somewhat similarly carved sticks in the British Museum 
exhibited as Norwegian. ‘This account has been prepared and the 
Clogg figured with the permission of the Director of the Science 
and Art Museum. 

It is made of oak, and in length is 1 ft. 8 in., while its breadth 
is 42 inches. It isin shape a rude and long oval, flat, and from 
2 to 3in. thick. The centre portion was cut away, thus leaving 
four edges (two inside and two out) and four flat surfaces. Two 
holes for suspension were cut, one at either end; but these were 
made in a gnarled part of the wood, and it would seem that at 
some period of its existence it was broken at this weakened part, and 
bound together again with two fastenings of iron, of which one only 
remains. At one end there is some carved decoration. This is a 
very simple design, being merely a line cut into the wood at a 
distance of about a quarter of an inch from the edge, and running 
parallel to it ; having at each side of it notches cut in a triangular 
form; while in the middle are the initials “S. EH.” Beyond what 
I mention, there is no ornamentation whatever. 

Almanacks of wood have, I gather, being used from time im- 
memorial. 

Dr. Robert Plot, in his Natural History of Staffordshire (folio, 
1686), speaks of “An ancient sort of almanacks they call cloggs, 
made upon square sticks, still in use here among the meaner sort 
of people, which I cannot but think must be some remains of the 
Danish Government, finding the same with little difference to have 
been used also formerly both in Sweden and Denmark, which 
being a sort of antiquity so little known that it hath scarce been 
yet heard of in the southern parts of England, and understood 


80 Scientific Proceedings, Royal Dublin Society. 


now but by few gentry in the northern.” He tells us that “there 
are some few of brass .. . but the most of them of wood, and 
these chiefly of box; others there are of fir, and some of oak, but 
these not so frequent . . . and others inscribed in a hollow bone. 

All people, no question, made them of such materials as 
they thought fittest for their purpose.” And as to their sizes, he 
says “there are some public, of a larger size, which hang commonly 
here at one end of the mantletree of their chimneys for the use of 
the whole family, and others private, of a smaller size, which they 
carry in their pockets.” He gives a sketch of one which was 
“in use in his native country of Staffordshire” at the time he 
wrote. 

The usual form was that of a razor-strop, some having four 
equal surfaces, and others being about 2 inches wide and 3 inch 
thick. The former, probably a later form, bore the marks for a 
quarter of the year on each surface; and the latter had the days of 
half the year on each side. Some were of an elaborate description, 
showing the Moon’s Changes and the Golden Numbers; but few 
were so perfect. They were first made centuries before the inven- 
tion of the printing-press, when a vast majority of the people were 
unable to read, and were probably originally employed in con- 
nexion with the churchmen, to whom, in early times, learning was 
confined. It is likely that one was kept in a public place in every 
parish or hundred ; and later, one might be found in every house, 
suspended by a cord or ring, or hung on a nail beside the fire-place 
in the hall or principal room, where every member of the household 
might use it. 

The days were marked on the edges by notches; and every 
Seventh day was indicated by a longer notch; while Holy Days 
and Saints’ Days were denoted by signs (peculiar to the occasion) 
on the flat surfaces, proceeding from the notches in the edge. 

I cannot find that cloggs similar in outline to that in the 
Museum were usual. A cursory glance at it would lead one to 
imagine that it is of some antiquity. In the first place, its shape 
is very inconvenient for handling. The squared staff with a 
handle is much less so; and I merely follow the laws of development 
in assuming that the improved form is of a date posterior to the 
other. And again (what much more surely goes to prove the local 
earliness of this class of clogg) the symbols which represent the 


MuLten—On a Clogg Almanack. 81 


Saints’ Days and Festivals are not numerous, nor are the daily 
notches always correct. A reasonable way to account for this is 
that when it was made such almanacks were not in very general 
use, and the signs to denote the different saints not being hitherto 
necessary were, with a few exceptions, unknown—at all events in 
the locality in which this clogg was made. 

The four edges are notched evenly and cleanly, and evidently 
with a sharp instrument, for in all cases the notches are made by 
two oblique incisions. The Sunday notches are carried round to 
one surface, and the signs to the other. 

Before I go seriatim through the principal days, I wish to say 
that in identifying the Saints’ Days I have received much valuable 
assistance from a Paper by Mr. John Harland, F'.S8.A., published 
~in 1865 in The Antiquary. 

The Almanack does not begin with Ist January, but with 14th 
April, which was reckoned as the commencement of Summer. 

The carving and initials | mentioned are here, and this alone 
would lead one to imagine that it is here the reading of the clogg 
begins. And from the position of the letters “S. H.” this carved 
end must be the top. Hach quarter reads downwards; the first, 
from 14th April (Pl. v. fig. 1), goes down the left half for thirteen 
weeks ; then, turning the stick (fig. 2), it continues on the same half 
(now at the right hand) from 14th July for another quarter; cross- 
ing to the other half it goes (always reading downwards) from 
14th October for the third quarter; and, again turning (fig. 1), 
the fourth quarter is read from 14th January. 

Beginning with Apri/ 14, I find a tree, Valerianus; April 16, 
St. Magnus, sign, probably some implement for loosening the soil, 
to signify the commencement of tilling; Apri 25, St. Mark, an 
unknown sign’shaped like a bottle; May 1, SS. Philip and James, 
a cross, one arm wanting ; May 3, Invention of the Cross, a cross ; 
May 14, an unknown sign, perhaps some local festival or family 
commemoration; May 15, St. Hallvard, a cross; May 18, a scythe : 
the first hay crop would be about this time; June 10, Eve of 
St. Barnabas, a cross; June 17, St. Botolph, a cross; June 24, 
St. John the Baptist, a cross; June 29, St. Peter, a sign, pro- 
bably meant to represent a key (Janitor); July 2, Visitation of 
the Virgin, a three-branched candlestick; July 8, a “'T” or rake. 
This is the last sign in the first quarter; but there is one day too 


82 Scientific Proceedings, Royal Dublin Society. 


many which, if it occur before the 8th, would bring the “T’”’ to 
the 7th, the Translation of St. Thomas a Becket; or, occurring 
after, the sign would mark St. Sunniva (July 8), a great holiday. 

Turning the clogg, I find on July 14 an unknown sign, the 
middle of the summer-half; July 20, St. Margaret, a cross; July 
22, St. Mary Magdalene, a cross leaning to one side, perhaps to 
show its position when being borne by our Saviour; July 25, St. 
John the Apostle, an unfinished sign, the previous one being in 
the way; July 29, St. Olaf (Danish King and Saint), an axe; 
August 8, the day on which his body was found, a smaller axe; 
August 10, St. Lawrence, a gridiron, signifying the manner of his 
death; August 15, Assumption of Mary, a three-branched candle- 
stick; August 24, St. Bartholomew, a sign shaped like a knife; . 
September 1, St. Giles, a cross; September 8, Nativity of the 
Virgin, an unknown sign; September 14, Exaltation of the Cross, 
an unknown sign; September 29, St. Michael the Archangel, a 
peculiar sign like a vane or rude balance: this day is not far past 
the Equinox; October 4, St. Francis, a simple cross. October 13th 
ends this quarter. 

Crossing over to the top of the other half, October 14, St. Cal- 
listus, a fir-tree; October 21, 11,000 Virgins, a cross; October 28, 
SS. Simon and Jude, a cross; November 1, All Saints Day, a three- 
branched candlestick ; November 11, St. Martin, a cross, with a second 
on one arm; November 18, a rude cross or sword ; November 23, St. 
Clement, a cross; November 25, St. Catherine, a cross; Movember 
30, St. Andrew, a cross; December 4, St. Barbara, a sign of un- 
finished appearance, probably on account of the close proximity of 
the next; December 6, St. Nicholas, a cross; December &, Concep- 
tion of the Virgin, a cross; December 13, St. Lucy, a cross; 
December 21, St. Thomas, a long line, possibly meant for a spear ; 
December 25, Christmas Day, a circle with radiating points, very 
likely to represent the guiding star; January 1, Circumcision, a 
circle with a line running through it; January 6, Hpiphany, a 
cross; January 11, St. Brictiva, a cross; January 13, St. Hilary, 
twenty days after Christmas, an unknown sign, similar in form to 
that on July 14, and probably marks mid-winter, as the latter did 
mid-summer. ‘This ends the third quarter, and turning the clogg 
I come to the last. 

Here is one mark too many. January 17, St. Anthony, a 


MutLEN—On a Clogg Almanack. 83 


cross; January 20, St. Sebastian, a cross; January 25, Conversion 
of St. Paul, a cross; February 2, Purification of the Virgin, a 
cross; February 3, St. Blaise, a very rude cross; February 24, St. 
Matthias, a cross; March 12, Annunciation of Mary, an erect 
cross, with a “St. Andrew’s cross’’ superimposed, forming thus 
eight arms. ‘This is the last sign or symbol on the almanack. I 
have gone through them all; but counting the days to the end of 
this quarter I find three too many, that is five altogether. These 
are evidently some of the original markings; but the outside edge 
at one end bears, besides these, forty-three additional notches. These 
seem to be much more recent than the others, and to have been 
made by a different hand, and are neither as deep nor so carefully 
cut as they. I imagine that some individual found the stick (per- 
haps a century or two ago), and, supposing it to be an ornament 
for wall-decoration, thought he would complete the carving left 
unfinished by the former whittler, and so continued the notches 
along the edge. The date “3Ist July, 1778,” and some letters, of 
which part of an “ H” and “en” are plainly seen, were scratched, 
as with a needle, on one end. But this, I should say, is of com- 
paratively recent execution. 

Now with regard to the manner of using this almanack. Every 
ordinary year ends on the same day of the week which commenced 
it, and so the next year must begin with the following day (or, 
after Leap Year, with the second day following); and it would 
seem that it was a matter of memory with the owners to move back 
one or more days of the week—the long notches being sufficient to 
remind them that every seventh day must be set apart for worship. 
For instance, this clogg begins with a Sunday notch—a long one. 
Next year this must mark Monday ; so the user would merely have 
to remember during that year that each notch really signifies the 
next day of the week; or, in other words, the series of names of 
the seven days, fifty-two times repeated, is moved back one notch. 
And so, for Leap Year, two notches. Thus the notches represent 
the days of the year, one in every seven being devoted to divine 
worship, to intimate which it is marked with a longer notch. So 
it is not strictly correct, however convenient, to speak of the long 
marks as “ Sunday notches.” 

Speaking of the symbols on the very complete ‘Staffordshire 
clogg,” Dr. Plot says they “all carry with them a rational impor- 


84 Scientific Proceedings, Royal Dublin Society. 


tance, some of them pointing out the offices or endowments of the 
Saints; others their martyrdoms ; and others some eminent action 
or other matter some way relating to the Saint; or else the work 
or sport in fashion about the time when the feast is kept.” 

From this extract, and the above description of the.clogg in 
the Museum, it will be seen that, owing to the frequent use of 
the cross and the fewness of symbols peculiar to certain saints, 
either (1) these signs were unknown to the maker, or that (2) he 
was too indolent to make them. But I think that the carved deco- 
ration at the commencement, the careful manner in which the 
original notches, crosses, and other signs are cut, would completely 
overthrow the latter assumption. 

Thus it would seem that it was made very many years ago; or, 
at all events, if so lately as the 17th century, in some remote dis- 
trict which had but little communication with any centre of infor- 
mation. 


Some of the symbols are similar to the Gothic Characters 
(Dominical Letters) engraved upon the Danish rimstocks and Nor- 
wegian primstaves (vide Plot’s Nat. Hist. Staf, folio, 1686, p. 421, 
&c.), but do not seem to occur with any regularity. 


Vide also Stephen’s Old Northern Runic Monuments of Scandi- 
navia and England. London and Copenhagen, 1866-7. Vol. 1. 


pede] 


_ XII.—NOTES ON SOME RECENT DISCOVERIES OF INTE- 
REST IN THE GEOLOGY, OF THE PUNJAB SALT 
RANGE. By A. B. WYNNH, F.G.S., F.R.G.S.1. 


[Read, February 17, 1886. ] 


Havine written several Reports and Papers upon the Geology of 
the Salt Range, I may be excused from any lengthened discussion 
of the subject now; but it is necessary here—at the distance of 
some 9000 to 6000 miles from that region—to allude briefly to the 
position of the Range, and to some of its general features in order 
that the points I have to notice may be better understood. 

Geographically, the Salt Range is somewhat peculiarly situated, 
subtending an angle formed by the meeting of two great moun- 
tain systems, the Himalaya on one side, and the Suliman Range, 
associated with the mountains of Afghanistan and Beluchistan, 
upon the other. 

From the thrust, apparently, communicated by these ponder- 
ous mountain masses the Salt Range seems to have been distorted 
along its general line of direction, as if forced to adapt itself to 
narrower limits than its full extent would occupy. It presents a 
grand facade of bold escarpments towards the plains and desert to 
the south, rising above these generally some 2000 feet, with a cul- 
minating elevation at Sakésir Peak of more than 5000 feet. From 
a northerly aspect, the whole range and its plateaux form, rela- 
tively speaking, a much less lofty feature, bordering the steppe-like 
upland, undulating country, called the Potwar, or Rawul Pindi 
District, which rises say 1600 to 1700 feet above the sea. 

Eliminating the numerous fractured or more complete curva- 
tures of its strata, the Salt Range may be regarded as presenting, 
otherwise, a generally uniclinal or semi-anticlinal structure, the 
outcrops in most cases being presented to the south, and the whole 
series of which it is formed taking ground so as to pass beneath 
the Potwar, northwards. 

Amongst its many interesting features, it may be noticed 
that the Salt Range is both geologically and economically 


86 Scientific Proceedings, Royal Dublin Society. 


important—geologically, because it 1s one of the only instances 
within the great realm of India affording the opportunity of 
studying the structure of more, very much more, than the mere 
surface deposits overspreading the border lands which intervene 
between the almost totally distinct areas of the ancient peninsular 
Indian formations, and the, geologically speaking, as a rule, more 
‘modern systems, of which the Himalayan and Suliman mountains 
are composed. In these two great regions, even though certain 
contemporaneous formations may exist, the representative groups 
belonging to each are found to possess most marked dissimilarity 
of character. 

Hconomically, the Salt Range is important by reason of the 
inexhaustible mineral wealth represented in its enormous deposits 
of rock-salt. Hxtending through a distance of 130 miles, with a 
known thickness in parts of 550 feet, these deposits have de- 
manded the construction of a special railway, and the bridging of 
a great river, the Jhelum (or Hydaspes of the Ancients), to facili- 
tate the transport of the salt, while the latest information at my 
command showed the (then increasing) annual salt revenue, to 
equal £382,653 sterling, although but a few of the mines known 
were being worked by Government, and the railway I have alluded 
to was not in existence. 

One strikingly-pronounced peculiarity of the geological sections 
displayed by the whole range is, that the series, as found in the 
centre and at either end, differ all three as to their com- 
prehensiveness ; groups present in the east die out to the west, 
while others come into those sections, notably the Carboniferous 
and Ceratite-beds, and at times some portions, like the typical 
Olive-beds, disappear both to the east and to the westward. The 
whole arrangement, though accompanied by some considerable 
evidence of overlap, shows a continuous tranquillity of deposition 
and succession, without intervening violent disturbance of any 
kind, between two constant horizons, that of the salt marl below, 
and that of the Tertiary formation at the top of the series—that 
is to say, from a period not newer than Silurian (according to com- 
petent Palzeontologists) through all the sons of Paleozoic, Meso- 
zoic, and Kainozoic time, up to the date of the Miocene or later 
disturbances to which the Salt Range, as well as the Himalaya 
and Suliman mountains, mainly owe their origin. 


Wynne—WNotes on the Geology of the Punjab Salt Range. 87 


One may well pause before accepting as real this apparent 
tranquillity of succession throughout so vast a range of geological 
chronology, but nevertheless the signs of a contrary state of things, 
so far as the Salt Range is itself concerned (and despite it being now 
an active earthquake region), if present at all, are so slight and so 
obscure as to evade the recognition of all but the most visionary of 
observers. 

With regard to the Salt Range series generally, after mature 
deliberation on the evidence as it stood, and after frequently ex- 
pressed concurrence, from its paleeontological aspect, on the part of 
Dr. Waagen when in consultation, it has been found to contain 
groups or divisions reckoned from above downwards, synchronous 
with the five newest principal divisions of the general geological 
scale. The Lias was not recognized, but the presence of a Per- 
mian horizon, at first included in our Carboniferous group, was 
subsequently recorded by Dr. Waagen (Pal. Ind., ser. x111., Pro- 
ductus Limestone Group, 1879, etc.).1 

This carboniferous or Productus Limestone, &c., is largely 
developed in westerly localities. Beneath it there are two azoic, 
or as yet unfossiliferous groups of uncertain age, but below them 
comes the Silurian or Obolus zone, the age of which was long 
since determined by the late Drs. Oldham and Stoliezka from the 
Obolus or Siphonotreta which I had found in it.? This zone rests 
upon a thick mass of purple sandstones (dying out to the west), 
which overlies the lowest and oldest group of all, the bright-scarlet 


Tn this publication, since our joint determinations were reached, Dr. Waagen has 
in several cases cast doubts upon these results, always avoiding any allusion to his 
own share therein. In his most recent Paper, Records Geol. Sur. Ind., vol. xix. pt. 1, 
1886, p. 22, received since most of the present communication was written, the same 
habit still seems to cling to him, as where, at p. 33, he relegates the Salt-pseudomorph 
zone, for which a Triassic age was indicated, at his own suggestion, to the Paleozoic 
period as not greatly different from older Carboniferous. ; 

This ‘‘Carboniferous group,’’ as originally undivided, is remarkable for having 
afforded the earliest known Ammonite, and the very peculiar Brachiopoda, Lyttonia and 
Oldhamina (Waagen), these or allied forms being only found in two or three other distant 
eastern localities—one in China, another in the Ural, and again in the Alpine Rheetic. 
The Oldhamina had previously been described, apparently from a single specimen, as a 
Bellerophon by de Koninck, whilst the interiorly-ribbed valves of Lyttonia had been 
mistaken for fish-teeth. Specimens of the fossils were laid before the meeting, and 
afterwards presented to the Museum, Trinity College, Dublin. (See Pal. Ind. ser. xiil., 
Salt Range Fossils 1., Productus Limestone Fossils rv. (fas. 2), 391 e¢ seq.) 

See my Report on Salt Range, Mem. G. 8. Ind., vol. xiv. pp. 95, 221. 


88 Scientific Proceedings, Royal Dublin Society. 


and crimson, gypseous, Salt-bearing marl. In their regular natural 
order, the newest uppermost, these groups have been classified 


thus :— 


(11. 


Kainozoic~ 


Siwalik and older, 


10. Eocene, Nummulitic, 


Sandstones and clays. 


Chiefly limestone, with coaly 
beds at the very base. ~ 


( 9. Cretaceous, Olive and other sandstones, 
and boulder beds. 
Mesozoic 8. Jurassic, Variegated sandstones and 
shales. 
7. Triassic, Red flags, greenish shales, 
&e. 
6. Carboniferous (and Per- limestones chiefly, contain- 


Eee ae SS 


mian of Waagen), . 


. Speckled Sandstones, 


ing the oldest known Am- 
monite. 
Sandstoneg, shales, clays. 


P , 4, Magnesian Sandstone, . Pale or whitish sandstones. 
aleeozoic 
8. Silurian, Dark, clunchy, sandy shale. 
.2. Purple Sandstone, Sandstone, carthy below. 
1. Salt Marl, . Red gypseous marl and salt. 


Premising that this list is compounded from various sections of 
the whole range, it will be observed that it includes no established 
representative of the Devonian or Old Red Sandstone period. 

Having thus briefly acquainted ourselves with some general 
features of the range, we may turn attention to the recent very 
interesting discovery of several determinable fossils by H. K. 
Warth, Ph.D., in a thin layer of conglomerate occupying a posi- 
tion near the top of the boulder-beds in the lower part of group 
No. 9 of the foregoing list, and of others at the base of the over- 
lying group No. 10. 

The locality which has furnished the fossils is in the eastern 
part of the range, about a place called Pid, at some distance north 
and north-west from the principal salt mines, named the Mayo 
Mines (after our distinguished fellow-countryman, Lord Mayo, 
whose brilliant career as Viceroy of India was brought to a melan- 
choly close by his assassination at the Andaman Islands). 

Many years ago Dr. Oldham found fossils just beneath the 


WynneE—Wotes on the Geology of the Punjab Salt Range. 8% 


coal crops at the base of the Nummulitic limestone hereabouts, but 
the credit of this discovery of the organic remains, at the lower level 
just above the local boulder-beds, belongs entirely to Dr. Warth, 
who has lived ere this, for years, in the salt range, as superinten- 
dent of the salt mines and Salt Revenue Collector, and who has 
lately been employed there by Government under the Board of 
Works, to conduct explorations and boring operations along the 
irregular, but laterally extensive, coal deposits. Being familiar 
with the local geology, notices of which have largely entered into 
his reports on the mineral ground; my friend Dr. Warth was most 
competent to search the country in even greater detail than my 
own opportunities afforded means of doing, at any one particular 
place ; and in this instance he has been most successful. 

The ,sections of the range in and about this region exhibit the 
following succession of beds :— 


11. Tertiary sandstone. 

10. Nummulitic limestone, with the coal beds! in a shaly zone at 
its base. i 
a. Pale or light-coloured, and reddish sandstone. 

9. ( b. Dark shales and olive sandstones with boulder-beds con- 

stituting the ‘‘ Olive series’”’ or group. 

These boulder-beds of g. b. resemble those of the Talchir group 
of Central India, according to the descriptions given and also 
verbal communication from Mr. W. Theobald. (I have not 
seen the Talchir boulder-beds myself.) They occur generally 
in the lower part of the Olive group, and they include a 
variety of rounded and sometimes glaciated metamorphic 
rocks, the glaciation of which was first noticed by Mr. Theo- 
bald. 

7. Red flags usually covered by a mass of red clays, the flaggy beds, 
characterised by their surfaces being often thickly covered 
with pseudo-morphic casts of cubical salt crystals. The beds 
have been doubtfully considered Triassic in my report, at the 
suggestion of Dr. Waagen. 

4. Pale magnesian, and silicious sandstone, and some shales— 
beds often ripple-marked, generally quite unfossiliferous or 
obscurely fucoidal. 


1 Specimen exhibited of a superior sample. 
SCIEN. PROC., R.D.S. VOL. V. PT. II. A 


90 . Scientific Proceedings, Royal Dublin Society. 


3. Obolus band—dark, clunchy, micaceous shales, with small Obolus 
or Stphonotreta. 

2. Purple sandstones of several hundred feet thickness. 

1. Salt marl, with salt beds and much gypsum. 


Except the groups Nos. 3, 10, and 11, of this list, most of the 
series has proved hitherto unfossiliferous, but in disturbed portions of 
the group No. 9, presumed to be Cretaceous, I found a few lanceo- 
late leaves and obscure shells, and in No. 4, some sharks’ and other 
teeth. It is in the upper portion of the (presumed) Cretaceous zone, 
with its glaciated boulders, and also in the basal portion of the 
almost immediately succeeding early Hocene or perhaps partly Creta- 
ceous group, that Dr. Warth’s recent discoveries of fossils have 
been made. He writes that at, and below, the outcrop of the 
coal he found more than one carapace of fossil turtles three-fect 
in length, accompanied by Belemnites, and fish teeth, all in the 
same band, probably latest Cretaceous or of earliest Eocene age. 
He has sent me none of the Chelonian remains, but specimens of 
the Belemnites and fish teeth, include, according to his own label- 
tickets, Lamna sp., Otodus sp., Hemipristis sp., and Capidotus sp. Ata 
lower horizon, but near the last, he found, in the Olive series, a thin: 
band of conglomerate absolutely continuous for several miles, many 
of the pebbles in which enclose small Conwlaria,! and a few other 
shells. ‘They occur also in the matrix in a rolled state, for one 
specimen, to which Dr. Warth calls special attention, is palpably 
an abraded, rolled Conwlaria, itself a pebble of the bed, taken from 
the matrix in this state—according to its label.’ 


1 Specimens exhibited, and presented with the others to Museum, T. C. D. 
; ? Dr. Waagen in his Paper (‘‘Note on some Palezoic Fossils, recently collected by 
Dr. H. Warth in the Olive group of the Salt Range.’’—Records G. 8. Ind., xix. p. 22, 
just to hand) does not agree in this statement of the case. He asserts the pebbles to be 
concretions and the beds to contain the fossils in sitw. I have other evidence that he 
spoke of these pebbles as concretions in October, 1885. His Paper had not reached me 
when I wrote the passage describing the mode of occurrence of the fossils, and my 
statement was made, both on the authority of Dr. Warth, who is perfectly competent 
to distinguish pebbles from concretions, whether in, or away from, the bed that had 
enclosed them ; and also from several examinations of specimens of these pebbles which 
I had received from Dr. Warth. They are of fine, grayish or brownish non-calcareous 
sandstone, of even homogeneous texture, well-rounded and worn, the surfaces cutting 
across the enclosed fossils, and they present no trace of any internal concretionary 
structure. Even if they have once been possibly nodules, they now bear the entire 
aspect of worn transported pebbles. i 


Wynne—Wotes on the Geology of the Punjab Sait Range. 91 


The genus Conularia (according to Nicholson) ranges from 
Older Palzeozoic up to Liassic, but those found by Dr. Warth have 
been at various dates attributed by Dr. Waagen to different Palao- 
zoie periods. In March, 1885, he considered them probably Silu- 
rian;' in October he called them Devonian,’ and early in the 
present year (1886) he most strongly asserts them to be of Carboni- 
ferous age.? The several fossils of this thin conglomerate layer, as 
found by Dr. Warth, have been determined by Dr. Waagen as 
tollows:—Conularia levigata, Morris; Conularia tenuistriata, M‘Coy ; 
Conularia, cf. irregularis, Kon.; Bucania, cf. Kuttaensis, Waagen ; 
Nucula, sp. indet.; Atamodesma (?) warthi, Waagen, n. sp.; Avi- 
culopecten, cf. limeformis, Morris; Discina, sp. indet.; Serpudites 
warthi, Waagen, n. sp.; Serpulites tuba, Waagen, n. sp. All of 
these except the Bucania are figured in Dr. Waagen’s plate, accom- 
panying his Paper.* 

The question remains, whence came these fossiliferous pebbles 
which do not seem to have been transported for any very great 
distance? Their material recalls nothing with which I could 
absolutely identify them from memory in the older groups of the 
Salt Range, their pale colour only—if even this is an original 
characteristic—might be more suggestive of their connexion with the 
‘Magnesian Sandstone (in which I could, however, detect no fossils) 


Writing about them, from their very locality, Pid, under date December, 1885, 
Dr. Warth says, ‘‘ From Choah-Saidun-Shah to Mackrach, I have found the thin con- 
glomerate bank with the pebbles which enclose Conwlarie, and two or three other shells, 
absolutely uninterrupted in the ‘ Olive series’ (upper portion). I send you a single 
Conularia (No. 16) which was found in a rounded-off state in the conglomerate. It is 
evident that the Conularia have not become fossils on the spot, but have been brought 
from a distant mountain as pebbles.’’ The label of this specimen, No. 16, states, in 
Dr. Warth’s writing, that he took it ‘‘in its present state from the face of the bed.”’ 

No person who inspects this rolled specimen can for a moment doubt the accuracy of 
Dr. Warth’s description or the derived character of itself and the other fossiliferous 
pebbles. Dr. Waagen’s account of them, for which indeed he advances no valid reasons, 
must therefore be received with caution or rejected, and with it almost the whole of his 
speculative deductions regarding the pebbles themselves, the layer which contains them, 
the ‘glacial boulder beds” of the Range, and his elaborate Paleontological views of 
the paleozoic and mesozoic geology of the eastern hemisphere and other regions. 

1 Records Geol. Soc. Ind., vol. xix. pt. i. p. 1. 

2 MS. Correspondence, London, October 9, 1885. 

3 Records cit., vol. xix. p. 29. 

4 Records cit., p. 25, etc., which reached me only in time to add the list of species 


given in the Press. 


H2 


92 Scientific Proceedings, Royal Dublin Society. 


than any other of these older sub-divisions, but there is still the 
difficulty that a fossiliferous conglomerate band, having an extent 
of several miles, would indicate the existence of the parent beds 
within measurable distance, while none of the layers of the Mag- 
nesian Sandstone group have given encouragement hitherto towards 
a hope that fossils would ultimately be found in them. 

Tfwe turn, unwillingly, from the possibility that the fossils were 
derived from this source, and look for another outside the Range 
itself, I know of no rocks in the outer Himalayan region to the 
northwards and north-east, more likely to have furnished the 
pebbles, and to the southward the flat alluvial plains and desert 
stretching away towards Sind are unbroken except by a small 
group of hills on the Chenab River, called the Korana Hills, 
separated by some forty miles from the Salt Range. I have seen 
these only from the range itself, but Dr. Fleming has described 
their rocks in a Paper to the Asiatic Society of Bengal (vol. xxii., 
new series, 1853), as dark, ‘‘ coarse-brown ferruginous quartzose 
sandstone, alternating with beds of a greenish quartzite, which in 
many places passes into silicious clayslate,” the sandstone being 
traversed by numerous quartz veins containing masses of hematite. 

Another observer, my former colleague, Mr. Theobald (JJ. As. 
Soc., Rengal, vol. xxi. p. 674), describes the rocks of these hills 
as deeply ripple-marked slate—the slaty structure feebly developed, 
gray in colour, stained red and yellowish, weathering to a deep- 
burnished brown, &c. ‘The whole of these characters stamp the 
rocks as widely different from any of the Salt Range groups: this 
of itself may favour the supposition that they formed the basal 
portion of a series, some part of which may have existed as the land 
‘from whence the Conularia-pebbles were derived. 

I have elsewhere mentioned the occurrence at more than one 
widely separated Salt Range horizon' of conglomeratic zones 


1 My view as to the difference of horizons at which these boulder-beds occur is not 
accepted in Dr. Waagen’s recent Paper in the Indian Records previously referred to. 
He regards the whole of these boulder-beds as glacial, and as occurring upon one 
horizon (p. 34). Stratigraphic conclusions are only geologically valuable when based 
upon carefully observed and compared facts and observations. My conclusions are the 
results of such examinations, and Dr. Waagen has advanced nothing which leads me to 
abandon them, while, I regret to say, the more I consider the matter the less reason I 
see far adopting his views to the contrary, these being directly at variance with strati- 
graphical facts. : 


Wrnne—Wotes on the Geology of the Punjab Salt Range. 98 


having usually a soft matrix and intensely hard metamorphic 
pebbles and boulders. ‘They are found just at the upper surface of 
the salt marl in the west part of the range, and at one or two other 
stages before being again largly developed in the lower part of the 
Olive group, which contains the Conularia-layer, apparently at a 
slightly higher horizon. There is no known source for any of the 
various metaphoric rocks to be found in these boulder-beds, includ- 
ing a red granite which would be easily recognized either among 
the Himalayan or Afghan mountains, if it existed in any force, so 
that here again an old metamorphic region, lying to the southward, 
suggests itself as forming land at various periods during the long 
record of the Salt Range rocks. Whether this may have formed, 
or not, a portion of the lost continent, Lemuria, supposed to have 
at one time united Africa with India, it is not for me to say; but 
failing the future discovery of similar forms or others of similar 
age in the hitherto azoic beds of the older portion of the Salt Range 
series, | am disposed to think these pebbles must have come from 
lands and rocks long since buried beneath the country southwards 
of the Salt Range, now occupied by the arid plains and deserts 
- which lie in this direction. 


By Wes oi 


XIII.—ON THE DIFFERENT VARIETIES OF IRISH PAVING- 
SETTS. By PROFESSOR EDWARD HULL, LL.D., 
F.R.S., Director of the Geological Survey of Ireland. 


[Read, February 17, 1886. ] 


Tur Royal Dublin Society seems the most suitable place for the 
discussion of all questions connected with the industrial products 
of Ireland, amongst which may be reckoned paving-stones. 

The production of paving-stones (or paving-setts, as they are 
generally called) is comparatively recent in Ireland, as this 
country has for a long time been dependent on imported stone, 
particularly from North Wales, notwithstanding that there are 
equally good sources of supply in various parts of Ireland itself. 
The discredit of depending on a foreign supply for a material 
which is abundant at home is happily being removed; and it is 
not improbable that, ere long, the course of this trade will be 
reversed; and that, instead of being a large importer, Ireland will 
become a large exporter of this useful commodity ; in fact, I may 
say that the current has already changed. 

In considering the question of the utilization of paving-setts, 
we have first to consider their qualities; next, the varieties of 
mineral composition and mode of formation; and, lastly, the 
sources of supply; which, as far as this Paper is concerned, will 
be specially restricted to those now existing in Ireland. 


I. Qualities requisite for Paving-setts—The qualities requisite 
for paving-setts may be described under three heads :— 


(a2) Uniformity of texture and composition, which we may 
call “ homogeneousness” ; 
(6) Toughness; and 
(c) Roughness of surface. 
A few observations may be made upon each of these heads :— 


(a) Uniformity of Texture and Composition.—This is an essen- 
tial quality in paving-setts, as it will be evident, on reflection, 


Huri—On the Different Varieties of Trish Paving Setts. 95 


that should the stone be wanting in homogeneousness it would be 
liable to break down under traffic, the softer portions giving way 
before the harder, and thus causing the blocks to collapse. It will 
be found that all the rocks used for the production of setts possess 
this quality, though differing from each other in other respects. 

(b) Toughness—I prefer the term to hardness, inasmuch as 
many very hard rocks—such as flint, chert, and quartzite, are 
deficient in toughness; and are, consequently, liable to crack, and 
splinter upon percussion. Such rocks are therefore unfitted as 
materials for paving-setts, which ought to be capable of with- 
standing the percussion caused by the sudden shock of the wheels 
of heavily-laden vehicles passing over their surfaces, not to speak 
of those caused by the iron-shod feet of dray-horses. 

(c) Roughness of Surface.—This is a quality not less valuable 
than that of toughness, and the best varieties of paving-setts are 
those which combine these three qualifications. It has been found 
by experience that some of the harder kind of paving-setts are 
liable, after some wear and tear, to have the surfaces worn smooth, 
and actually to become polished. In this state they become dan- 
gerous for street traffic; and, notwithstanding their durability, 
they are held in less favour in the large manufacturing towns of 
the North of England than was formerly the case; and other 
kinds of stone, though somewhat softer and less durable, are 
preferred, in consequence of their ability to maintain a rough 
surface. 


II. Varieties of Stones for Paving-setts.—I now pass on to con- 
sider briefly the varieties of stone suitable for the manufacture of 
paving-setts, and therefore combining in a greater or less degree 
the qualities previously enumerated. ‘They may be considered 
under three heads :— 


(a) Those of sedimentary origin, such as grits and sand- 
stones. 

(b) Those of igneous origin, of a granitoid character; 
including quartz-porphyries. 

(c) Those also of igneous origin, but belonging to the 
variety commonly known as “ whinstone”; in- 
cluding basalt, dolerite, diorite, and felstone, 


96 Scientific Proceedings, Royal Dublin Society. 


(a2) Grits and Sandstones.—The formation which yields this 
class of paving-setts in greatest quantity is the carboniferous; and 
beds belonging to the millstone grit division in Lancashire and 
Yorkshire are largely worked for paving-setts. ‘This rock, owing 
to its granular structure, is probably the softest of all the varieties 
of stone capable of being used for paving purposes; still, it is very 
largely used in the streets and roads of the North of England for 
pavements; and is found, when properly selected, to answer well 
where the traffic is not excessively heavy. Gritstones have the 
useful quality of preserving a rough surface; and can be set quite 
close, side by side. As far as I am aware, there are no paving- 
setts made from the carboniferous rocks of Ireland, though I have 
no doubt some of the beds of grit of this formation in the counties 
of Sligo, Fermanagh, Leitrim, Donegal, &c., are capable of pro- 
ducing them. In Belgium the gritstones of the Upper Devonian 
formation, known as the ‘ Psammite du Condroz,” are very 
largely used for paving the streets of the manufacturing and 
other towns. 

(6) Granitoid Varieties. —This group includes not only granites, 
but quartz-felstones and porphyries ; in which the constituents are 
quartz, felspar, with mica or hornblende as accessories. ‘These 
components are, more or less, in a crystalline condition, and have 
solidified from a state of igneous fusion. In consequence of this, 
the mineral constituents are firmly bound one to the other, and a 
condition of “toughness” is imparted to the mass favourable to 
its use for paving-stones. The presence of mica, if in large flakes, 
would prove a source of weakness, in consequence of its want of 
cohesion with the other minerals; but when in minute flakes, this 
mineral, by its disintegration, enables the stone to preserve a con- 
stantly rough surface. 

Paving-setts belonging to this group are worked at Bessbrook, 
Goragh Wood, and Castlewellan, in Ireland; and at Mount 
Sorrell, in Leicestershire. 

(c) Whinstones.—The stones belonging to this third division 
differ from those already described in texture and composition. 
They consist of crystalline aggregates of felspar and augite, or 
felspar and hornblende, together with magnetic iron-ore dis- 
seminated in minute grains, and with occasionally other minerals, 
such as olivine, and chlorite, in small quantities. The presence of 


Huti—On the Different Varieties of Irish Paving-Setts. 97 


iron gives to these rocks a higher specific gravity than those of the 
granitoid class, in which iron is either absent or ocours in exceed- 
ingly small proportions. Thus, while the average specific gravity 
of granitoid rocks may be taken at 2°65, that of the whinstones 
may be taken at 3:0; so that, in the case of a contract for 
purchase by weight, the granitoid rocks are in favour of the 
purchaser. : 

The rocks of the “ whinstone” class are generally exceedingly 
tough, and setts taken from them are capable of withstanding the 
heaviest traffic ; but their chief defect is the tendency to wear into 
smooth surfaces and become slippery. Being essentially compact 
in structure, the component minerals are incapable of individually 
disintegrating, and thus preserving a rough exteridr where subjected 
to wear and tear. This is the case, at least, with regard to the 
finer and denser varieties; and it is therefore important, in select- 
ing a stone of this class for paving purposes, to see that it is 
largely crystalline-granular, as such varieties will be less liable to 
wear smooth. 

Quarries for making paving-setts from whinstone have been 
for some time past opened at Ballintoy, Co. Antrim, and Arklow, 
Co. Wicklow. The Welsh setts from the quarries at Penmaen 
Mawr belong to this group, and have been largely used not only 
in England but in Ireland, where stone of similar or identical 
qualities is to be found in abundance. The great obstacle to the 
manufacture of paving-stones in this country has been—not so 
much want of capital or enterprise on the part of the employers of 
labour—as want of knowledge in the art of shaping the stones on 
the part of workmen. This want is now being supplied, as Irish 
stonemasons are being instructed by workmen from Wales and 
England ; and as we possess abundance of the raw material, we 
may look forward with hope to a large and flourishing trade in 
various parts of the country. 

In considering the qualities of different varieties of paving- 
setts, and the purposes to which they should be applied, I think 
we may fairly come to the conclusion :—that for streets subject to 
excessively heavy traffic, the whinstone varieties, especially those 
of largely-crystalline structure, are the more suitable; while for 
streets with ordinary traffic, those of the granitoid class will be 
found sufficiently durable, and, from wearing rough, more advan- 
tageous. 


98 Scientific Proceedings, Royal Dublin Society. 


Trish Localities for Paving-setts.—Having personally visited 
most of the quarries from which paving-setts are now being 
obtained, I will, in conclusion, give a short account of each, 
commencing at the north coast of Co. Antrim. 

Ballintoy Quarry.—This quarry is worked by the Eglinton 
Chemical Co., Limited. The rock consists of a largely-crystalline 
dolerite, forming a cliff 80 feet in height, in rude columns, and 
about 200 yards in length. The stone is shipped at the little 
harbour of Ballintoy and sent to Glasgow, Londonderry and other 
places. It consists of a crystalline aggregate of augite, plagio- 
clase, olivine, and magnetite. I understand that paving-setts could 
be delivered in Dublin, at 22s. per ton. 

Goragh Wood.—This quarry belongs to Messrs. J. Robinson 
and Son, of Belfast, and is opened by the side of the Great 
Northern Railway at the junction for Newry and Armagh. The 
rock consists of fine-grained granite of quartz, felspar, and black 
mica in small flakes. The paving-setts are sent to Belfast and 
other parts of Co. Antrim, and have likewise been used in Man- 
chester, Oldham, Liverpool, Rochdale, and other towns in England ; 
and the stone for building and decorative purposes, takes a fine 
polish. It can be delivered in Dublin at prices varying from 
18s. 6d. to 21s. per ton, according to the size of the “ cubes.” 

The Castlewellan granite is considered more suitable than the 
Goragh Wood stone for paving, being somewhat harder; and is 
being used by the Belfast Harbour Commissioners for paving the 
street along the Donegall-quay, where the traffic is naturally 
heavy. For building purposes the stone was selected, amongst 
other places, for the Bishop Rock Lighthouse at St. Mary’s Island, 
Scilly. Paving-setts of this stone can be delivered in Dublin at 
prices varying from 19s. 6d. to 22s. per ton, according to the size 
of the “ cubes.” 

Bessbrook, near Newry.—These quarries, which belong to the 
Bessbrook Granite Co., Limited, are opened in granite, consisting 
of quartz, felspar, and black mica in small flakes. The rock is ex- 
tensively worked both for setts and also for building and ornamental 
purposes, and the stone is shipped at Newry, or sent by rail. I 
understand the company have offered to supply paving-setts to 
Dublin at 22s. 6d. per ton, though the regular price is 24s. The 
stone is used in various parts of England, including Manchester, 


Hurti—On the Different Varieties of Irish Paving-Setis. 99 


Chester, and Wigan, and for several of the approaches to railway 
stations where there is heavy traffic. 

Arklow, Co. Wicklow.—These quarries, which belong to Mr. 
Parnell, M.P., produce three separate varieties of stone. From 
the samples I have received they may be described as belonging 
to the whinstone class. 

No. I. is a coarse-grained crystalline diorite, or greenstone, of a 
dark-green colour, consisting of felspar, hornblende, and some 
magnetite. It occurs in the form of a dyke penetrating the Silu- 
rian slate along the banks of the Aughrim river, about a mile 
above Wooden Bridge Inn. The rock breaks with a rough surface, 
and shapes well into setts. 

No. IT. is a coarsely-crystalline felstone of a dark-blue colour, 
with a little pyrites in distinct crystals. It breaks with a rough 
surface, and is lighter than No. I. 

No. III. may be described as a compact felstone of a bluish 
colour, with even fracture. Setts from this rock would be liable to 
wear with a smooth surface, on which account it is, in my opinion, 
inferior to Nos. I. and II. 

The stones from the Arklow district are now being largely used 
in the city of Dublin; and I understand from Mr. Parke Neville, 
the Borough Engineer, that the price paid under last contract was 
24s. per ton delivered at Harcourt-street Station or on the Quays. 

Tn offering these few remarks on the nature and sources of Irish 
paving-stones, I have no intention of personally recommending any 
special stone to public favour; but only of affording data on which 
selections may be made for special purposes and localities. It will 
be gathered from what I have stated that, in my opinion, different 
varieties of stone have their own special uses ; and that, in provid- 
ing for the requirements of a large city, certain varieties may be- 
more usefully employed in one part than another, according to the 
nature and amount of the traffic. 


[ 100 ] 


XIV.—NOTES ON TWO IRISH SPECIMENS OF EDWARDSIA 
TIMIDA (QUATREFAGHS). By G. Y. DIXON, M.A. 
(With Prats VI.) 


[ Read, January 20, 1886. ] 


Edwardsia timida (Quatrefages). 


HistToricat. 
Edwardsia timida, . . Quatrefages, 1842, Ann. des Sci. Nat., 
Nex. 2) Xvill., sp. 7.0, pl 2aarosmle 
Edwardsia harassi, . . Quatrefages, 1842, idid., p. 71, pl. 2, 
fig. 2. 


Edwardsiella harassi, . Andres, 1884, Die Actinien, Fauna u. 
Flora, d. Golfes, v. Neapel, ix. p. 94. 
Edwardsiella tinuda, . Andres, 1884, ibid., p. 96. 


Tus species has previously been recorded from only one dis- 
trict—Chansey, Manche (North France), where it was found by 
Quatrefages.. Last autumn, however, I had the good fortune to 
find two specimens at Malahide, county Dublin. With the excep- 
tion of an immature Edwardsia found by Professor A. C. Haddon 
at Salthill, Dublin Bay,’ this is, I believe, the first example 
of this genus recorded from Ireland. Quatrefages separated 
E. timida from E. harassi on four grounds:—(1) the tentacles in 
E. timida, he thought, were in a single row, while those of 
E. harassi were arranged in two rows. I believe this distinction 
ig only due to the different state of extension of the disk. For 
when the animal is much extended the tentacles appear to be 
uniserial; but when it is not extended to its full size they seem 
to be in two distinct rows, alternately arranged. (2) Quatre- 
fages describes the mouth and disk of H. timida as flat, and those 
of E. harassi as being raised so as to form a terminal papilla. 
This distinction also I believe to be based on a merely temporary 
condition : in both my specimens the mouth and disk were continu- 


1 Proc. Roy. Ir. Acad., 2nd ser., vol. iy., p. 527. 


Dixon—On Two Trish Specimens of Edwardsia timida. 101 


ally undergoing changes of form, being sometimes flat, sometimes 
raised into a pointed cone, with the lips protruded and folded back. 
(3) Quatrefages makes the consistence of the investment a further 
ground of distinction. Andres, however (/.c., p. 93), refuses to 
give any weight to such a matter as this, as a specific distinction 
among the Edwardsidae, considering that the nature of the invest- 
ment largely depends on the environment of each individual. In 
connexion with this question, too, it should be borne in mind that 
Quatrefages found the one example on which he rests his L. harassi 
. in a different locality from where he found the specimens which he 
referred to LH. timida. (4) Lastly, £. timida measures 6-7 em. in 
length, while #. harassi only measures 55cm. This would not 
appear to me to be an important difference, but merely to depend 
on the temporary elongation or contraction of the animal. 

Quatrefages referred all Hdwardsidae to one genus, Kdwardsia. 
Andres has constituted two genera in the sub-family, reserving the 
name Kdwardsia for all such species as have sixteen tentacles, and 
classing under the name Edwardsiella all those that have twenty 
or more tentacles, including, of course, the EL. timida and EL. harassi 
of Quatrefages. In the present state of our knowledge no advan- 
tage would seem to follow from multiplying the genera, and there- 
fore I have adhered to the nomenclauture of Quatrefages. My 
two specimens evidently belong to the same species, but as they 
differ somewhat from one another, I have described both. All the 
features in the following description are common to both specimens, 
except where a separate description is given of each under the 
several designations of a and 3. 


DESCRIPTION. 


Form.—Column thin, very much elongated; divided into 
physa, scapus, and capitulum. 

Physa—delicate, smooth, retractile within the scapus ;- when 
fully distended exceeding the scapus in diameter, and sometimes 
rising from it by an abrupt step; studded with minute suckers ; 
divided into eight segments by eight lines, which correspond with 
the insertions of the mesenteries ; no terminal pore is present. 

Scapus—long, slender, vermiform, slightly tapering towards 
either extremity, cylindrical, smooth, without tubercles or longitu- 
dinal ridges or furrows; clothed with a transversely corrugated 


102 Scientific Proceedings, Royal Dublin Society. : 


investment, which is opaque, leathery, flexible, and rough; the 
investment breaks off abruptly at each of its extremities, and is 
more deeply furrowed and wrinkled, and studded with particles of 
sand at its anterior end. When the animal is much contracted 
eight longitudinal ridges sometimes rise at the anterior extremity, 
and extend for a very short way down the scapus: no other longi- 
tudinal marks are visible except when the animal is much dis- 
tended, in which case the lines corresponding to the insertions of 
the mesenteries can be seen through the investment, especially in 
the region towards the physa. When the investment is removed 
the insertions of the mesenteries are seen in the body-wall as in 
Peachia hastata. 

Capitulum—delicate, retractile within the scapus, columnar ; its 
body-wall is divided perpendicularly into eight broad regions, 
separated by as many narrow flutings; the broad regions (which 
apparently correspond to Gosse’s “ invections”’), being somewhat 
swollen. 

Tentacles—marginal in two rows, the inner usually pointing 
upwards, the outer extending horizontally ; obtuse, slender, hardly 
tapering towards the top. 

aa—tentacles 22 in number, 8 being arranged in the inner row, 
one at each end and three at each side of the mouth. ach of the 
inner tentacles thus occupies the centre of one of the inter-mesen- 
terial chambers. From between the mesenteries which run into 
either end of the mouth (“the directive mesenteries’’) there rises 
but one tentacle. At one end of the mouth each of the chambers 
adjoining that formed by the directive mesenteries have four ten- 
tacles—one in the inner and three in the outer row. ach of the 
remaining chambers gives rise to three tentacles—one in the inner 
and two in the outer row. 

((—tentacles twenty in number, arranged ten in the inner 
and ten in the outer row. 

Disk—usually elevated into a cone; each inter-mesenterial space 
being arched upwards between the mesenteries, and having a some- 
what puffed and swollen appearance. 

Mouth—prominent ; lmear; lips frequently protruded and, 
folded back over the disk. 

Colour.— Physa—pellucid white, marked with eight white lon- 
gitudinal lines. 


Dixon—On Two Irish Specimens of Edwardsia timida. 108 


Scapus—(1) Investment ; brownish-orange for two-thirds of its 
entire length ; at the anterior end it grows darker, till it becomes 
almost black at the top. 

(2) Body-wail—pellucid pale pinkish flesh-colour, showing the 
insertions of the septa as whitish longitudinal lines. When the 
scapus is much distended the orange convoluted edges of the 
mesenteries may be seen hanging free in the interior. 

- Capitulwm—transparent brownish red, deeper above, paler 
below; each invection bears an arrow-head mark of pure opaque 
cream-white pointing upwards, and about one-third of the total 
length of the capitulum below the tentacles. Between these arrow- 
heads and the scapus, on either side of each invection, closely 
adjoining the arrow flutings, there is an opaque white linear spot, 
running parallel to the direction of the flutings. When the animal 
is viewed by direct light, the flutings and invections seem to be 
separated by lines of transparent white; but when the animal is 
seen by transmitted light these markings disappear, and the opaque 
marks mentioned above seem black. The red colour of the cesopha- 
gus may be seen through the body-wall of the capitulum. When 
the animal is contracting, rings of pale brownish-red appear to 
encircle the capitulum, and are especially conspicuous across the 
white arrow-heads. These rings are really wrinkles caused by the 
process of contraction. Their presence proves that the white marks 
are imbedded in the substance of the body-wall. Sometimes the 
white colouring on the disk shines through the tentacles so as to 
be quite visible at the margin, when the animal is seen from the 
side. ‘This effect, at the first view, would almost lead one ta sup- 
pose that the margin, or top of the capitulum, or the back of the 
tentacle foot, was marked with a white band; but this is not really 
so, the back of the tentacle foot and the margin being quite mono- 
chromatic. 

Tentacles—brownish-red, transparent, apparently with a core of 
the same colour, only denser. No bands or markings are present, 
the colour being uniform throughout. 

Disk a—cream-white, with the eight septa showing through as 
brownish-red lines; the gonidial and gonidular tentacles have a 
dense white blotch at their base, but no other mark. Lach of the 
remaining six primary tentacles has a band of white which encloses 
the front, but does not extend round to the back of its foot. Below 


104 Scientific Proceedings, Royal Dublin Society. 


this band there is a V-shaped brownish-red mark, the apex of 
which points towards the mouth ; while on either side of the mouth 
are two slightly-curved short linear marks running towards the 
mouth. There are no markings on the disk which correspond with 
the secondary tentacles. 

Disk (—translucent pale brownish-red, with no coloured mark- 
ings corresponding to the mesenteries; the bright-red oesophagus 
shining distinctly through in the centre; the mouth encircled 
with an opaque white band, which was shaded off gradually into 
the brownish-red which forms the general colour of the disk. Hach 
tentacle is marked at the foot with a crescent of opaque white : 
these crescents, though they come very close to each, do not coalesce, 
but are separated by a thin streak of the brownish-red which is 
prolonged between them. ach crescent is shaded off into the 
general colour of the disk on the side towards the mouth, while 
the side next the tentacle is sharply and definitely drawn. 

Mouth a—with brownish-red lips; on the inner edge of the 
lips are six pairs of small white spots, which correspond with the 
six lateral primary tentacles. 

Mouth (s—with bright-red lips, quite plain, without marks or 
spots. 

Dimensions.— 

Length—contracted, 35-40 mm. 

A expanded, 65-70 ,, 
Expanse of disk and tentacles, 8 mm. 
Diameter of scapus, greatest, 5 ,, 

” 12) least, 2 ” 


Locality.— Malahide, county Dublin, south bank of the estuary, 
opposite the Hotel; in mud, among stones, at extreme low water. 

I cannot conclude this description without stating that I am 
well aware of the difficulty raised by the account given of the 
arrangement of the tentacles in example 8. However, I can only 
say that, after repeated observations made during the three months 
the animal was alive—observations always made, I may add, almost 
in the hopes of ascertaining the contrary to be the fact—I am 
quite certain that ten, and not eight, was the number of the ten- 
tacles in the inner row. In connexion with this point it is worthy 
of note, that Quatrefages, in his description of the disk of the very 


Drxon—On Two Irish Specimens of Edwardsia timida. 105 


species now under consideration, says, five lines of a violet black 
run from the circumference of the disk to the mouth, and that in 
the intervals between these lines five others of the same colour, 
only less marked, are to be seen. Agassiz, too, is evidently of 
opinion that there need not be an absolute conformity between the 
tentacles and mesenteries in Edwardsia. In describing the de- 
velopment of a larval Edwardsia (Arachnactis), he says: ‘ Les 
nouveaux tentacules se forment independamment des cloisons ova- 
riennes, et je n’ai pas pu en suivre l’indice exactement, relativement 
aux huit cloisons principales; mais comme je l’ai deja indiqué, 
les jeunes tentacules se forment toujours vers une des extremités— 
a V’extremité opposée de la bouche ou se trove le long tentacule 
impair.”—Archiv. Zool., 1873, vol. X11, p. XXXVill. 


Hapsits. 


The habits of my two specimens during the few months they 
lived in captivity were very much the same as those described by 
Quatrefages and by Andres in his description of a kindred species 
(Intorno all’ £. claparedii, Mittheil. Zool. Stat. z. Neapel, 1881, 11., 
p. 129). 

I kept them in a small glass jar with about one-fourth inch of 
sand. They sometimes adhered to the sides of the glass vessel by the 
physa, sometimes burrowed in the sand, leaving only the capitulum 
protruded, and sometimes they wallowed about on the surface of 
the sand quite free: in the last-mentioned condition they were 
usually distended more fully than when fixed in the sand, or when 
adhering by the physa. Their shape and dimensions varied greatly 
according to the degree of their distension, but I think hardly to 
the extent observable in other free anemones, the presence of the 
investment seeming to limit them somewhat in this respect. There 
was generally a constriction marking the division of the scapus 
from the physa; and sometimes, when the animal was contracted, 
the capitulum was separated from the scapus in the same manner ; 
but I never saw these constrictions passing up or down the body, as 
one sees in Halcampa or Peachia; on the contrary, they appeared 
to be fixed and constant in their position. 

The physa was frequently covered with particles of sand, which 
seemed to be adhering in a thin coating of slime, for if the physa, 


SCIEN. PROC., R.D.S. VOL. Y. PT. IT. 


106 Scientifie Proceedings, Royal Dublin Society. 


when in this state, was suddenly drawn up into the scapus, the 
particles of sand formed a ring round the posterior portion of the 
investment. When alarmed, it withdraws its disk and tentacles 
into the capitulum, and the capitulum itself into the investment, 
by a process of invagination. During the earlier stages of this 
process the white markings on the disk and on the capitulum may 
be detected through the body-wall, their position being inverted 
by the invagination. 


NOTES ADDED IN PRESS. 


Since the above Paper was written I have obtained six more specimens 
of E. timida at the same locality. In colour the new specimens differ 
considerably from each other, and from those already described. I have 
set out the points of difference of all the individuals I have seen in the 
accompanying Table. 

The constant characteristics of the species seem to be— 


1. The ratio of the length to the diameter, 1 to 18. 

2. The pellucid pink colour of the capitulum, disk, and tentacles, varied 
with opaque white marks. 

3. The absence of tubercles and longitudinal ridges. 


EXPLANATION OF PLATE VI. 


Edwardsia timida (Quatrefages). 


Fig. 1. Side view of animal, natural size. 
» 2. Side view x 4 diam. 
», 98. Diagrammatic sketch of the disk of a x 8 diam. 
,, 4. Disk of 6 x 8 diam. 
», 9. Capitulum closed x 6. 


Numb 


Specimen. of 
Tentac 
a 22 


20 


Y 20 
) 18 
E 92 


j 21 
n 29 
0 24 


ur of Disk. 


haracteristic marks in 


e). 


with white crescents 
of the tentacles, and a 
ound the mouth. 


pink: at the foot of 
e is a white mark like 
very broad cross-bar : 
sed in a white ring. 


, with decided white 
und the feet of the ten- 
the mouth inclosed in a 


rose, with decided white 
pees the feet of the 
rom each of which two 
radial lines run towards 
which is inclosed by a 


lucid pink, with white 
wee the feet of the ten- 
he mouth inclosed by a 


, but speckled with very 
Ke spots; the feet of the 

closed in white cres- 
houth inclosed in a white 


ot observed. | 


(Zo face page 106. 


Colour of Investment. 


Tawny orange, black above. 


Tawny orange, black above. 


Pale drab throughout, with 
a black irregular stain on 
the scapus. 


Tawny orange, paler above. 


Tawny orange, black above. 


Tawny orange below, pale 
drab above. 


Tawny orange, black above. 


Tawny orange, black above. 


Specimen. 


Number 


fo) 
Tentacles. 


Colour of Tentacles. 


Colour of Capitulum. 


Colour of Gsophagus. 


Cok ur of Disk. 


(Zo face page 106. 


Colour of Investment. 


a 


y 


22 


20 


20 


18 


22 


21 


22 


24 


Pellucid brownish-pink, not tipped 
with white. 


Pellucid brownish-pink, not tipped 
with white. 


Pellucid pink; tipped with white, 
which is scarcely perceptible in 
full expansion. 


Pellucid pink ; tipped with cream- 
white, and marked with minute 
brackets )( on the back at the 
foot. 


Pale pellucid rose, tipped with 
white cream. 


Very pale pellucid pink, with con- 
spicuous white tips. 


Pellucid pink, with faint white 
tips. 


Pale rose, not tipped with white. 


Pellucid brownish-red, with decided 
arrow-heads and linear marks. 


Pellucid brownish-red, with decided 
arrow-heads and linear marks. 


Pale pellucid pink, with blunt ar- 
row-heads, and no linear marks. 


Pale pellucid pink, with irregular 
white marks instead of arrow- 
heads, and with very conspicuous 
linear marks. 


Pellucid pink, with arrow-heads 
and linear marks. 


Very pale pellucid pink, with slight 
and flattened arrow-heads, and 
no linear marks. 


Pellucid pink, with irregular marks 
instead of arrow-heads, and with 
the usual linear marks. 


Pellucid pink, with arrow-heads 
and linear marks. 


Brownish-red. 


Brownish-red. 


Brownish-red. 


Brick-red, with white longi- 
tudinal marks, which may 
be seen through the capi- 
tulum. 


Brick-red, with white longi- 
tudinal marks, which may 
be seen through the capi- 
tulum. 


Yellow ochre. 


Brick-red. 


Brick-red. 


White, with «characteristic marks in 
red (as abo ve). 


Pellucid pink, with white crescents 
at the feet of the tentacles, anda 
white ring round the mouth. 


Pale pellucid pink: at the foot of 
each tentacle is a white mark like 
a H, with «1 very broad cross-bar : 
mouth inclosed in a white ring. 


Pellucid pinlx, with decided white 
crescents rcund the feet of the ten- 
tacles, and he mouth inclosed in a 
white ring. 


Pale pellucid rose, with decided white 
crescents inclosing the feet of the 
tentacles, from each of which two 
short white radial lines run towards 
the mouth, which is inclosed by a 
white ring. 


Very pale pelllucid pink, with white 
crescents round the feet of the ten- 


Tawny orange, black above. 


Tawny orange, black above. 


Pale drab throughout, with 
a black irregular stain on 
the scapus. 


Tawny orange, paler above. 


Tawny orange, black above. 


Tawny orange below, pale 
drab above. 


tacles, and he mouth inclosed by a 
white ring.) 
} 


Pellucid pink, but speckled with very 
minute white spots; the feet of the 
tentacles inclosed in white cres- 
cents, the niouth inclosed in a white 
ring. 


[Not observed. ] 


Tawny orange, black above. 


Tawny orange, black above. 


“F 


} DAK Do Sait @ ‘ ae 


IDOE 


Pom, i 


XV.—NOTE ON SOME IMPROVEMENTS IN EQUATORIAL 
THLESCOPE MOUNTINGS. By HOWARD GRUBB, F.R.S. 


[Read, January 20, 1886.] 


New Declination Slow Motion.—The slow motion arrange- 
ments usually used in Equatorials are of either of two forms, viz. :— 

(a) an endless screw working into a sector or portion of a 
toothed circle of long radius; or, 

(0) A screw applying, or pushing directly against an arm, that 
arm being kept in contact with the screw by a spiral or some other 
form of spring having a considerable range of motion. 

The first (a) possesses the disadvantage that, however carefully 
made, it is impossible it is quite free from “loss” or “ back lash”’ ; 
and, consequently, the position of the telescope is not perfectly 
determinate in declination, which fault is inconvenient when deli- 
cate measures are required. 

The second (0) has practically no “ back lash,” as spring keeps 
the arm in perfect contact with screw, but it has the disadvantage, 
that whatever range of motion is required, the spring must be 
capable of working through the same range; consequently the 
spring will be much stronger in action at one end of the range than 
the other, unless it be made very long indeed, in which case its 
action is uncertain and unpleasant. 

To remedy these defects the author has devised the following, 
which possesses the advantages of both :— 

ABOD (fig. 1) is a portion of the arms attached to telescope, or 
cradle, on which is planted the block (4), forming the bearing of the 
screw. ‘The nut (7) is in the form of a ball working in a socket on 
the extremity of the clamp-arm EFG. A short stiff spring (S) is 
attached to this clamp-arm, bearing, not directly against any part 
of other arm, but against end of a second screw of same pitch as 
the main screw, the nut of which (00) is toothed on edge, and works 
into a wheel of equal size (yp) on main screw. The point of this 
second screw, therefore, advances as much in one direction as the 
frame ABCD is carried in other, according as the milled head 


108 Scientific Proceedings, Royal Dublin Society. 


is turned; and, consequently, the point of the screw does not sen- 
sibly vary in its position with respect to the clamp-arm EFG. A 


short stiff spring can therefore be used, and the disadvantage above- 
mentioned disappears. 

New Position Finder.—The inconvenience of having to rise 
from the observing-chair to read the Right Ascension and Declina- 
tion circles of an Equatorial has tempted opticians to devise many 
contrivances by which the circles may be read from eye-end of tele- 


scope. In some cases the following piece of apparatus will probably 
be found useful. It can be attached at any convenient position 
near eye-end of telescope. It (fig. 2) consists of a circular level 


Gruss—IJmprovements in Equatorial Telescope Mountings. 109 


mounted on two axes at right angles to one another, thus allowing 
of universal motion. The apparatus is so mounted on telescope 
that one of the axes (aa), which may be called its declination axis, 
is parallel to declination axis of telescope. If, now, telescope be 
pointed to equator, and meridian, and circle (cc) on declination of 
axis of position-finder made to read zero, the other axis (pp), 
which may be called its polar axis, will be parallel to polar axis of 
equatorial. The bubble of level L is now adjusted to centre when 
the circle (45) on its polar axis reads zero. 

It is evident now that the Right Ascension and Declination 
circles of position-finder will read the same as the Right Ascension 
and Declination circles of telescope, at any position provided the 
bubble be brought to centre of glass. 

To find any object, it is only necessary to set the circles of this 
little position-finder to same readings as the Right Ascension and 
Declination circle of telescope itself would have to be set to, and 
turn instrument round till bubble becomes level. 

Addition to Existing Arrangement for Slow Motion 
in Right Ascension.—The slow motion in Right Ascension 


- 
FIGS 


\\ 
i} 
1] 
ty 
Be 
if 


Vi 


which the writer generally applies to his instruments has often 
been described. It consists (fig. 3) of a pair of differential wheels 
(dd’) fixed on the adjoining ends of a pair of shafts (SS) in line 


110 Scientific Proceedings, Royal Dublin Society. 


with each other, into which wheels a pinion p is geared, this pinion 
being carried on a stud fixed to a disc (e) revolving free on shaft: 
when not in use the pinion acts as a clutch, and both wheels and 
shaft, pinion and disc, all revolve together by clock. When a 
fine motion is required in either direction, a cord passing over a 
eroove in disc is pulled in one direction or other; the pinion 
revolves round differential wheels, and as the wheels have not 
exactly the same number of teeth, produces a differential motion 
which practically accelerates or retards clock-movement as long as 
cord is pulled, but the moment the cord is released all revolve 
together, as before, at normal rate. 

The only objection that has ever been made to this motion is, 
that it requires two hands to work it—one to keep the cord a little 
“taut,” and the other to pull, as otherwise the cord would slip 
round without gripping. There is more difficulty in overcoming 
this objection than may at first sight be apparent, for it will not 
answer to apply anything which will produce friction between cord 
and pulley, except at the moment the cord is pulled. 

The following plan has, however, proved quite successful :— 

A little frame (aa) is fixed over the pulley disc in such a manner 
that it is capable of a rocking motion in centre (a). This frame 
carries four rollers (0, 0’, c,c’). The pulleys (0, 0’) are simple grooved 
rollers; (¢, ¢’) are covered with india-rubber rings. When cord kf is 
pulled, the whole frame slightly tilts, and brings the rubber-covered 
roller (¢’) into good contact with cord on disc pulley, and prevents 
it slipping. When cord /’ is pulled the other rubber-covered roller 
(c) is brought into contact. The moment either end of cord is 
released the rollers return to their normal position out of contact. 
As the roller which is brought into contact is nearly a whole cir- 
cumference from the point where the cord is let off, the cord has a 
good grip on the pulley, and never slips. 

New Slow Motion im Right Ascension.—The recent 
advances in celestial photography have rendered it desirable to 
have a more delicate and accurate slow motion in Right Ascen- 
sion than has hitherto been required. ‘The necessity for this is 
partly due to the fact that up to the present no clock-work has 
been found sufficiently accurate to keep the star absolutely steady 
on the photo plate for the long period necessary to obtain an 
image of faint stars; and consequently it has been the practice 


Grusp—Improvements in Equatorial Telescope Mountings. 111 


for the operator to have a very powerful finder-telescope with 
cross-lines set on a particular star, and to watch this star during 
the progress of exposure, and if he saw it vary its position by 
the smallest quantity to bring it back again by the slow motion 
of the instrument. Anyone who has experience in these matters 
will know how very difficult it is to obtain a slow motion which is 
perfectly certain in its action, has no back lash, and acts promptly, 
without and at same time setting the instrument into swing. The 
new slow motion which the writer has devised is not subject to 
these faults, and may thus be described :— 

In the slow motion by differential wheels, described above, it is 
evident that if dise carrying pinion be simply stopped, a retarda- 
tion or acceleration (according to relative positions of wheels) will 
be produced, to a slight extent. Suppose the wheels to have twenty- 
nine and thirty teeth, the speed will be altered =, part quicker or 
slower. Now, suppose two such differential sets of wheels be placed 
side by side on the shaft (which of course should be cut in two 
places), but with wheels so arranged that a stopping of one disc 
(and pinion) will produce an acceleration of 3', and the stopping 
of the other will produce a retardation of 34. <A pair of electro- 
magnets working a clutch (or simple levers with strings) can be 
used to enable the operator, who has his eye applied to finder, to 
bring either the retarder or accelerator into action at any instant ; 
and the action is so gentle that no swing or disturbance of the 
instrument takes place. 


[11204 


XVI.—A CLASSIFICATION OF THE SPONGES. By PROFESSOR 
SOLLAS, D.Sc., F.R.S.E., &c. 


[ Read, June 15, 1885. | 


Tuer Porifera are a phylum, divisible into the two classes— 
1. ‘Plethospongie. 1. Caleispongie. 
The Plethospongiz may be subdivided into three sub-classes— 
i. Hexactinellida. u. *Demospongie. ii. Myxospongie. 


The Demospongize embrace the great majority of sponges, and 
are divisible into the two tribes—the Monaxonida and Tetracti- 
nellida. 

The Monaxonida include as orders—(1) the Monaxona (Monac- 
tinellida, Auct.) and the Ceratosa, the latter clearly of polyphylitic 
origin, and derived from several families of the former; (2) the 
Tetractinellida include the orders Choristida (Sollas) and Lithis- 
ida. 

The Myxospongie are not degenerate, but persistent askeletal 
forms, and include two orders—Halisarcosa and Chondrosiosa 
(excluding Corticium and its allies). 

The classification, as far as the orders, may stand thus :— 


PORIFERA (PHYLUM). 


Cxass 1.—Plethospongie. 


i ue cages OrveR 1.—Lyssakina (Zittel). 
Sub- cLass i.—Hexactinellida. ee 2.—Dictyonina (Zittel). 
TRIBE @. { », 1.—Monaxona. 
; Monaxonida. »,  2.—Ceratosa (Grant). 
»»  iU.—Demospongiee 
TRIBE Ob. { », 1.—Choristida (Sollas). 
Tetractinellida. » 2.—Lithistida (O. Sedt.). 
or . 1.—Halisarcosa (O.Scdt.). 
‘ ii.—Myxospongie. { ” 
d Bese era »,  2.—Chondrosiosa. 


Cuass II.—Calcispongiz. 


1 rAnOos: a great number or crowd. 2 Seudtnpos: common. 


Fer 


XVII.—THE RELATIONSHIP OF THE STRUCTURE OF ROCKS 
. TO THE CONDITIONS OF THEIR FORMATION. By 
H. J. JOHNSTON LAVIS, M.D. 


[Read, February 17, 1886. ] 


Introduction.—Two great questions of Vulcanology, of which 
our knowledge is still very limited, are in the first place the causes 
that bring about the wide range in force and character of volcanic 
activity ; and, secondly, the difference in structure and composition 
of the resulting products. In the present Paper it is proposed to 
discuss a portion only of these very complex questions. 

Those who have lived in a still active volcanic region, and have 
gazed over the landmarks of former activity, and compared them 
with those at present in progress, cannot but be struck by the evi- 
dence afforded of the enormous disproportion in the exhibition of 
voleanic energy from one time to another. Before 1631 the crater 
of Vesuvius was clothed with trees, brushwood, and grass, where 
goats were pastured, while the only sign of igneous action was 
the presence of two small lakes of warm water occupying the 
bottom of that depression. ‘The quietness of this sylvan scene was 
only broken by the twitter of birds, the shepherd’s chant, or the 
wind-rustled leaves. Let us compare this state of placidity, or stall 
more that in which no sign whatever existed of the endogenous 
activity in the time of Spartacus, with those gigantic, prehistoric 
eruptions which tore away 1,000 metres or more of the mountain 
top, and hollowed out a cavity equal to a cone with a base diameter 
of three kilometres and a height of 1400 to 1500 metres. Even 
the Plinian eruption was an insignificant affair compared with its 
four predecessors. Between these two extremes in the vital activity 
of a volcano we have all stages of gradation. 

Yet the phenomena of Vesuvius bear the proportion of child’s 
play to a giant’s exploits when we compare them with the catas- 
trophe of Tomboro, Krakatoa, Cotopaxi, the Icelandic volcanoes, 
-and many others. Meditating on these facts can hardly fail to 
awaken within us the inquiry as to the actuating cause of the 


variability in functions, if we may so call them, of a volcano. 
SCIEN. PROC., R.D.S., VOL. V. PT. IIT. K 


114 Scientific Proceedings, Royal Dublin Society. 


Source of Energy stored up in Igneous Matter.—Disregarding for 
the time being the unsettled question of the condition of the earth’s 
interior, let us assume! that we have an almost unlimited supply 
of igneous material ; let us then ask ourselves, whether this material 
supplied in varying proportions is capable of producing an equiva- 
lent difference in the display and character of the volcanic forces. 
A moment’s consideration will satisfy us that such is certainly not 
the case. There is no doubt that in a great explosive eruption a 
very large amount of matter may be ejected, but as it 1s always in 
the form of pumice its apparent bulk is larger than its real one. 
On the other hand, in paroxysmal eruptions we have enormous 
quantities of igneous magma ejected in a fluent form without 
exhibiting that amount of energy that occurs in the first case. If 
we compare the amounts, by weight, of matter (essential)* ejected 
during the Plinian eruption of Vesuvius with the lava outpours of 
1631, we should find no ratio between them and the eruptive energy 
exerted on each occasion. Many still more striking examples 
might be given of the gigantic though comparatively quiet outflows 
of basalt when compared with low crater rings of the Hifel and 
other volcanic districts. 

Were facts otherwise, so that the greater the eruption the 
greater the amount of material extruded, we should then have 
fairly conclusive evidence that the water which is the main motive 
power in a volcano was contained uniformly diffused throughout 
the igneous magma, as held by Rev. O. Fisher and others.* Of 
course we must admit that in distant regions such might really be 
the case, but it is not reasonable to suppose that it is so in a single 
locality, a necessary datum for such an argument. In consequence 
of this we are reduced to search for some local influences that are 
brought to bear upon an isolated portion of the igneous magma, 
and the only rational way in which we can suppose any such mass 
to be isolated would be when it has entered its duct on its way 
from its source to the surface. 


1 This is compatible with all the more reasonable theories regarding the physical 
state of the deeper parts of our globe. 

2 T mean only that which is really extruded de novo, and not materials torn from the 
erater sides. 

3 Physics of the Earth’s Crust, 1881, p. 187. 


Lavis—-On the Structure of Rocks. 115 


Passing over the older and more crude theories relating to the 
flowing’ down of water by crevasses, and so coming in contact with 
the molten lava, or over the fantastic hypothesis of Davy down to 
that of Peacock, we find the question severely tackled in 1881 by 
three eminent geologists: Professor Prestwich,’ who attributes 
eruptions to the percolation of water to the porosity and cleavage 
planes of rocks, and not to fissures, but yet does not admit of that 
intimate mixture of the water with the magma which anyone 
accustomed to watch the lava in its fluent state soon becomes con- 
vinced of. Professor Sollas* at the same time and place recognizes 
the intermixture of water and lava, and supposes the former to 
exist in the liquid state, but he fails to explain the variability of 
eruptive action except by relief of pressure. ‘The changes of pres- 
sure, as explained by the author, are obviously insufficient to bring 
about inactivity on the one hand, or explosive‘ eruptions on the 
other. Besides, we should expect voleanoes in the same region to 
act quite synchronously. It is to Professor Judd that merit is due 
for the recognition of the fact that the igneous magma may, under 
_ pressure, absorb gases such as water is at high temperatures, and he 
gives in illustration a number of analogous examples, but does not 
treat of the conditions of absorption and dispersion of such water. 

Just to this point we are provided with a demonstration of what 
is really the motive power of volcanic eruptions, and it is here I 
propose to take up the thread and discuss the conditions under 
which this water is absorbed, retained, and expelled. 

Let us take an illustration, namely, the solution of carbonic 
anhydride in water itself. Carbonic anhydride is, at the normal 
temperature and pressure of the atmosphere, a gas; but by either 
increasing the pressure or lowering the temperature it may be 
reduced to the liquid or solid state. The water of volcanoes, at 


! Baron Dietrich in Ferber, Lettres sur la mineralogie, &c., de l’Italie, 1776, 
p. 207; also Braccini. 

2 «© Some Observations on the Causes of Volcanic Action.’’—Reports, Brit. Assoc., 
1881. 

3 “The Connexion between the Intrusion of Volcanic Action.”—Reports, Brit. 
Assoc., 1881. 

* It may be here mentioned that I do not use yarowysmal in the same sense as Scrope, 
but to indicate those increments of activity that occur from time to time during chronic 
activity, always accompanied by the outpour of lava, leaving explosive for those erup- 
tions with only fragmentary pumiceous or scoriaceous pumice ejectamenta. 


K2 


116 Scientific Proceedings, Royal Dublin Society. 


the normal pressure of the air and the temperature of lava, is a 
gas; and, like carbonic anhydride, may be rendered liquid or solid 
by increasing pressure or lowering temperature. By removing 
either of these secondary conditions the more volatile materials in 
the two cases return to their gaseous state. Now, carbonic anhy- 
dride in the presence of water is much more easily condensed, and 
dissolves simultaneously in that liquid, the solubility propor- 
tionally increasing with the pressure. Water is equally soluble 
in molten silicates, as is shown by its escape from lava, and its 
solubility likewise increases with the pressure, unless downright 
opposed to known physical laws. Between these two cases of 
gases soluble in liquids there is not only a physical, but also 
a chemical, analogy, for in both cases we have to deal with gase- 
ous oxides soluble in liquid ones. 

In the case of the solution of carbonic anhydride in water, 
and, in fact, of solutions of all gases in liquids, we find that the 
quantity of gas absorbed increases with the pressure, provided the 
liquid does not solidify (as exhibited in the spitting of silver). 
We find also that the pressure remaining fixed, an increase of 
temperature has a tendency to reconvert the condensed, or, more 
properly, dissolved gas, again into the gaseous state; or, in other 
words, we find that the tension of such a solution increases with 
the temperature. The absorption of oxygen by molten silver, and 
of the same gas and carbonic anhydride by iron and steel, as 
demonstrated by Troost, are familiar examples of fluids at high 
temperatures taking up gases. It is at the same time evident that 
the critical point of water no longer enters into the question, as it 
is held in solution like CO? in water, both occupying volumes 
much nearer their liquid than their gaseous state. 

The conditions under which igneous matter commences its 
course towards the surface may, no doubt, be very variable, and 
whether such be due to secular cooling of our globe, and con- 
sequent straining and fracturing of its outer surface, it is not our 
present business to discuss. As already stated, we have every 
reason to believe the voleanic magma, as it exists in its original 
site,’ contains dissolved in it little, if any, water, although many 


' Whether this forms the centre of our globe, a stratum between the nucleus and 
crust, or exists as isolated reservoirs, in no way affects that part of the question now 
under discussion. 


Lavis—On the Structure of Rocks. Wiles 


hold, on account of Sorby’s discoveries, that the fluid portion of 
the earth’s interior is an igneo-aqueous solution. We must first 
prove that granite, or at least that studied by Sorby and others, 
was not an intrusive rock in porous strata. In other words, it 
must be proved that granite is the primitive rock cooled without 
the intervention of secondary water. 

It, therefore, on being transferred from great to lesser pres- 
sure, would only exert that small amount of expansion which is 
proper to its chemical components, which would therefore undergo 
no change of state, but remain as liquids under normal atmo- 
spheric pressure at the earth’s surface. In fact, whatever expan- 
sion tended to take place in transferring the volcanic magma from 
great depths to the surface would be more or less balanced by the 
corresponding loss of heat, and consequent tendency to contract as 
a result of that, so that only a change in volume would take place, 
if any, in proportion to the different power of the two agencies to 
accelerate or diminish contraction. This theory of the solution of 
water in lava, and not lava in water, is incidentally mentioned by 
the Rev. O. Fisher.’ 

Extrusion of Igneous Matter through Dry, or nearly Dr ry, Rocks 
to the Surface.—Should such voleanic magma in its native state 
reach the surface, it might overflow without any explosive mani- 
festations whatever, and consequently no cone of scoria or other 
fragmentary materials would be formed around the exit, and the 
locality of this would be only detected on a plain by the possible 
formation of domes, or mamellons, where the lava was sufficiently 
viscous. Neither should we expect such an exudation of fluid- 
rock to be accompanied by mechanical vibrations other than that 
dependent upon the formation of the fissure, or duct, by which the 
lava escaped, and which formation would be dependent upon 
causes extraneous to the actual expulsion of the fluid magma. 
That such favourable conditions may sometimes occur, so that the 
actual dyke may traverse strata that are not water-logged, we 
cannot deny, and possibly some of the great basalt plains of 
America and elsewhere may so have originated; yet, geology 
teaches us to consider such to be rather the exception than the 
rule. 


1 Physics of the Earth's Crust, 1881, p. 190, 


118 Scientific Proceedings, Royal Dublin Society. 


Intrusion of Igneous Matter into Dry, or nearly Dry, Rocks, but 
not reaching the Surface.—Should a fissure opening downward to 
the voleanic magma be formed by secular cooling or other means, 
we should expect that it would be simultaneously filled by the 
oozing in of the igneous magma. ‘This mass of fused silicates, at 
a very high temperature, will now undergo a series of changes, 
which we will attempt to trace. ‘The first thing will be the cool- 
ing of a layer of the magma, which is in actual contact with the 
walls of the fissure; and should that substance be in a purely 
vitreous condition, a pitchstone salband of variable thickness will 
result. Now, should the conductivity of the surrounding strata 
be great, or should the temperature of the magma be near solidi- 
fication point, then that process will continue from the salband 
inwards through the whole mass, and a blind dyke will result. 
On the other hand, should the surrounding strata be bad con- 
ductors, already heated, and the magma at a very much higher 
temperature than that of its solidification, so that its heat might 
be given out quicker than the surrounding rocks could absorb, 
any salband that might at first have been formed would be re- 
fused, and such re-fusion might extend some distance into the 
surrounding rocks, continuing to do so until the supply of heat of 
the injected material was exhausted. Should the surrounding 
rocks be infusible, a chemical interchange would take place be- 
tween the igneous and solid matter, resulting in the metamor- 
phism of the former, and a corresponding change in the latter. 
Although I am not personally acquainted with many examples in 
illustration of this condition, probably some of those dykes which 
are so abundant in the Western Isles and Highlands of Scotland, 
described by Jameson and others who have followed him, will 
serve. If the intrusion of the igneous magma takes place in solid 
rocks, which themselves are at a high temperature from pressure— 
crushing or conduction upwards from below—three things will 
probably result. First, the magma, from the small absorption of 
its heat by the surrounding rocks, would require a very long time 
to cool, and that would also occur in a very gradual and uniform 
manner, so that an extremely course crystalline structure would 
result. This is the case in a great number of pegmatite granite 
veins. Secondly, no salband will be formed, and partial fusion of 
the fissure walls may occur, so that in gneisose rocks the line of 


Lavis—On the Structure of Rocks. 119 


demarkation between them and the intrusive granite, or syenite, 
may be very ill-defined. Thirdly, the condition will be highly 
favourable to contact metamorphism, which, in such cases, often 
extends into the surrounding rocks for very considerable distances, 
often many hundreds, or even thousands, of yards.1_ Jukes main- 
tained that the granite forms the basis of many volcanoes, being 
the source of the eruptive matter. It has been observed by Cotta, 
that the smaller the dyke the smaller the grain,’ which is ex- 
plained by the more rapid cooling of the smaller mass. We have 
the same in nearly all kinds of dykes, where the nearer we 
approach the outer surface the finer the grain; though volcanic 
dykes in cones are an exception for some minerals. Negri and 
Spreafico, in describing an expansion of porphyry near Lugano, 
show that the felspars near the surface are invisible, so that the 
rock is a euritic porphyry. Towards the centre of this great 
mass the crystals are distinct, but round and imperfectly formed, 
whilst in the dyke, which supplies this great mass, the crystals 
are very perfect and large, often reaching three centimeters in 
diameter. We see, therefore, that the perfection of crystallization, 
and the type of resulting rock, are in direct relation with the 
length of time and quietness of the cooling of the magma. In 
the same way we may explain the crystals in the salbands of some 
dykes, being smaller than those in the more central part. 

On the other hand, we may meet with various intrusive rocks 
with more or less purely vitreous salbands, in which, in many cases, 
the line of demarcation is often distinct and very sharp between 
the dyke walls and the intrusive matter. ‘There are also cases, as 
in the dykes of liparite of the Ponza isles, which possess thick pitch- 
stone salbands which are soldered to the walls of the quartzose 
tufas. It would seem that the great resemblance of the two rocks 
in chemical and mineralogical composition, and therefore the small 
difference between their points of fusibility, a very slight excess of 
temperature in the intrusive rock would be sufficient to fuse the 
walls, and yet cool rapidly enough to prevent complete crystal- 
lization, thus leaving the vitreous salband. This is aided, no 
doubt, by the low heat conductivity of the surrounding tufas. 


1 L. Gatta, Vulcanismo, 1885, p. 28. 
2 Naumann, Lehrbuch der Geologie, 1858-1868. 


120 Scientific Proceedings, Royal Dublin Society. 


Even in granite, although there is no vitreous salband which 
would be incompatible with its coarse, well-crystallized structure, 
Naumann describes granite dykes in which the grain is finer 
towards the margin. 

It seems probable that where intrusion takes place into rocks, 
the cleavage planes of which are nearer the horizontal in direction, 
the loss of heat will take place slowly, and we should expect to find 
coarse-grained granites and trap rocks; whereas, the more the 
cleavage planes approach the vertical the greater will be the 
rapidity of cooling. This is a question well worth inquiring into, 
for Jannettaz' has shown that the major axis of the isothermic 
ellipsoid in crystals is parallel to the principal planes of cleavage, 
and in rocks with the planes of schistosity.’ 

Intrusion of Igneous Matter into Porous Aquiferous Strata.-—The 
same results as in the last case may be looked for, but we shall see 
that superposed upon them there is another series of far greater 
importance. Let us suppose the fissure formed, injected, and that 
a salband has solidified. The water in the immediate neighbour- 
hood will tend to increase in temperature until it arrives at the 
same degree as that of the lava, since in most cases the enormous 
superincumbent pressure will have proportionally raised the boiling 
point. Then again, as the water exists bound up, as it were, within 
the pores of some permeable rock, little convexion circulation is 
permitted, at the same time that expansion to the gaseous condition 
furthermore is resisted. This shell of superheated water is only 
separated from the igneous magma by the salband, which according 
to varying circumstances may differ very much in thickness, and 
so will act as a more or less imperfect porous septum between the 
igneous matter and superheated water. Although probably not 
possessing exactly the same physical characters as the porous septum 
in dialysis, nevertheless it no doubt would permit diffusion to go 
on between the two fluids which it separates, or even the porous 
rocks themselves may play that part. Besides, we have another 


+ Mémoires sur la propagation de la chaleur dans les corps cristallisés (Ann. Ch. et 
Ph., 4° serie, t. xxix., p. 5; Bull de la Société Géologique de France, 3° serie, t. Ie 
et suly.). 

* As the stratification of strata in general approaches nearer to the horizontal than 
the vertical, the conditions will be most favourable for the retention of the internal 
heat of our globe. 


Lavis—On the Structure of Rocks. IIL 


striking resemblance to the process of dialysis, for the igneous 
magma is in a vitreous state, which we may take as the representa- 
tive of the colloids,! whilst the superheated water in all probability 
may still be regarded as a crystalloid. In consequence of this we 
should look for endosmosis as the principal function, although the 
metamorphism of surrounding rocks, which in the case of the 
existence of salbands is comparatively slight, would indicate some 
amount of exosmosis. In the case of the blind fissure being con- 
verted into a channel through which the igneous magma circulates, 
then no doubt the salband would, in most cases, be refused or 
carried away by other means, and the permeable rocks would then 
play the part of the septum. In fact, even in a blank fissure we 
can comprehend that no salband may exist. 

The rapidity of this endosmosis of water, and its diffusion 
through, or solution in, the colloidal-like magma, will obviously 
depend upon a variety of circumstances, such, for instance, as the 
composition of the magma, the form of fissure, and therefore 
amount of surface exposed, pressure, &c. ‘This we see portrayed 
in the illustrations we chose ; for if carbonic anhydride is in contact 
with the calm surface of water solution takes place very slowly. 
A knowledge of this fact is practically made use of in the seltzer- 
water machine, in which a number of lashers revolve with great 
rapidity in a chamber filled with water and the carbonic anhydride, 
so that a very large surface of each is brought into contact by the 
churning motion, and consequently solution takes place with very 
great rapidity. 

But to return to the main question, this absorption of water 
will go on at the expense of heat to the igneous magma, which, 
however, will only lose so much as will raise the amount of water 
absorbed to its own temperature. ‘This loss will not, of course, be 
very great, since there is no conversion of a liquid into a gas. 
Nevertheless this loss of heat, combined with that due to the con- 
duction away by the surrounding rocks, may be so great that the 
igneous magma may reach its point of solidification, and further 
action will be prevented by the fissure being now filled by a cooled 
rock mass. 


+ At any rate as far as the silica, and probably the alumina and iron oxides, are 
concerned. 


122 Scientific Proceedings, Royal Dublin Society. 


On the other hand, should such not have taken place, as the 
amount of water absorbed increases, the tension of the fluid mass 
will proportionally do so also. ‘There will arrive a time when the 
tension of the fluid mass will exceed the resistance of the surround- 
ing rocks, or the superincumbent pressure, which will result in the 
rending asunder of them and the extension of the fissure. Such 
extension may be sufficient to make it reach the surface forming 
the site of a volcano, or as it extends and gives place for expansion 
the tension may proportionally so decrease until the balance is 
restored before the surface is reached. The extension of such a 
fissure will rather tend towards the surface, as least resistance 
would be encountered in that direction. 

Such an extension of a fissure will give rise to two or more very 
distinct series of vibrations: first, we shall have slow ones extend- 
ing over a considerable length of time, due to the gradually in- 
creasing compression around the expansible matter which, if 
apparent at the surface, would assume the characters rather of tilt 
than that of anearthquake. Local elevation of a small area such as 
occurred at the Starza of Pozzuoli, pending some years before the 
outburst and formation of Mount Nuovo, or the same thing at 
Torre del Greco in the Vesuvian eruption of 1861. The actual 
rending and enlargement of the fissure will give rise to a series of 
vibrations of small amplitude, such as are first registered in an 
earthquake.’ These will be immediately followed by the sudden 
arrest of expanding matter coming in contact with the walls of the 
fissure, which space it injects immediately. The effect is well 
imitated by allowing steam to escape from a boiler under high 
pressure, and suddenly closing the opening. Other examples are 
the sudden injection by water of a blind and collapsed hose, or the 
rapid closing of a tap from which was flowing a stream of water 
under pressure, conducted through a pipe of some length. This 
impact of the fluid matter against the solid fissure walls is followed 
by a series of diminishing oscillations or throbs. This group of 
disturbances no doubt constitute the more powerful or destructive 
portion of the earthquake, and the character of these vibrations, 


‘J. A. Ewing, Earthquake Measurement, Mem. Sci. Depart. Univ. Tokio., No. 9, 
p. 54, and following. 


Lavis—On the Structure of Rocks. 123 


which we should deduce on the above theoretical grounds, com- 
pletely coincide with earthquake registration. 

The extension of the fissure may have been sufficient to allow 
of the formation of steam, which may collect together throughout 
the pasty mass as bubbles; and, should solidification soon follow, 
the resulting dyke-metal would present a vesicular or amygdaloidal 
structure. On the other hand, the expansion may only have taken 
place to such a point, that no conversion of liquid into gas has 
taken place, and as a result we should look for, in case of solidifi- 
cation, a dyke presenting no signs of vesicularity. The finding of 
a dyke-metal, in which no vesicularity is manifest, is no proof that 
at some time it may not have had such; for, were cooling not to 
follow soon on vesicularization, the renewed gradually increasing 
pressure would again compel the steam to redissolve in the magma. 
These facts probably account for the rarity of a vesicular state of 
granite, though even this is sometimes known to occur as in the 
island of Mull, and that of the plateau of the Palais du Roi, Lozére, 
described by Lecoq.' 

Under the two former circumstances we should expect the first 
to end in solidification more often than the second; for, by the 
conversion of the dissolved water into steam, a very much larger 
amount of heat would be used up, proportionally of course to the 
amount of conversion that took place. 

By the progressive extension of the fissure a larger area of 
igneous rock surface will be exposed to the conditions which have 
been described, so that the tendency will be towards the more rapid 
absorption of water, and consequent crisis between tension and re- 
sistance. Besides, from the larger amount of expansive matter 
capable of acting, the effects will be more violent each consecutive 
time. 

The facts are borne out in such examples as Jorullo and Monte 
Nuovo, and are now probably in progress under Casamicciola, in 
the island of Ischia. In such examples we find, that for a long 
period earthquakes occur at distant intervals, but that these have a 
gradual tendency to follow each other progressively more often, 
and often increasing in destructiveness at one spot, although the 
area affected may proportionally become more concentrated. At 


1 Les époques géologiques de l’ Auvergne, I., page 465. 


124 Scientific Proceedings, Royal Dublin Society. 


last the frequency may become so great that the intervals are 
almost imperceptible until the fissure reaches the surface, and the 
igneous matter finds a vent for its expansion. 

Of course the sheet of igneous magma may solidify at any part 
of its journey towards the surface in consequence of— 


(a) Loss of heat from conduction away by the surrounding 
rocks. 


(b) Raising the acquired water to the mean temperature of 
the solution of silicates in which it is dissolved. 


(c) By loss of heat in consequence of expansion during the 
extension of the fissure. 


(7) By gradual escape of water in the form of steam or 
vapour through fissures so supplying fumaroli. 


(e) By convection currents of waters forming Geysers or 
thermo-mineral springs. 


It is a common fact that the water-bearing qualities of different 
rock strata are widely different, and we also know that an igneous 
dyke may traverse an alternation of more or less permeable strata. 
Where the supply of water was greatest, conductivity and other 
things being equal, there would take place the greatest amount of 
diffusion of that lquid through the igneous magma. Were this 
latter a perfect fluid, and non-viscous, the more aquifarous, pro- 
bably lighter, part would soon diffuse itself in all directions, render- 
ing the whole a homogeneous mass. We know, however, that all 
lavas are exceedingly viscous, especially the more highly silicious 
ones, and therefore such diffusion would take place very slowly. 
This would be aided by the upper part of the column being lighter, 
from that portion being placed under the more favourable condi- 
tions for absorbing water. 

The more porous the strata the greater the tendency will be 
for the conduction away of the heat of the magma, either directly 
or by the aid of convexion, currents of water, or by the conversion 
of the latter into vapour, where pressure is so low as to permit it. 

Liztrusion or Eruption of the Igneous Magma into the Atmosphere. 
—I{f we suppose, simply for the sake of brevity of argument, 
the lava canal to be a tube of uniform size between the source of 


Lavis—On the Structure of Rocks. 125 


igneous matter and the surface (which, however, it never is), and 
that such a canal traversed rock strata of different permeability ; 
then the magma enclosed in the tube would consist of a series of 
more or less saturated aquiferous strata, superposed on each other 
in the same order in which each part was exposed to a portion of 
the canal wall. Now, should a sudden exit of magma occur from 
the tube at its upper extremity, the expansion, or, in other words, 
eruption, would take place with a violence directly proportional to 
the amount of dissolved water, and the temperature of that por- 
tion of the mass nearest the surface, at different periods of the 
eruption. The eruption will therefore lull or augment, as that 
portion, being expelled originally, occupied a more or less favour- 
able site for the absorption of its contained volatile matter. The 
examples given at the end of this Paper seem to indicate that this 
departure from what is a normal type of eruption of a truly homo- 
geneous magma is of rare occurrence. My experience in the field 
has been chiefly drawn from the basic voleanoes of Vesuvius and 
Roccamonfina (Leucite basalts), Mt. Vultura (Haiiyn basalt), 
Mt. Nuovo (Phonolite), Ventotene and San Stefano of the Ponza 
group (Andesite), and Ischia (Trachyte). Were the suppositions 
in the above case true, and were the entire chimney or canal com- 
pletely emptied in each eruption, then we should expect every 
stratum of ejectamenta representing an eruption to be composed of 
a series of components alternating with each other in direct relation 
with the eruptive variations, and with the structure of the earth’s 
crust beneath the voleano. Besides, in any one volcano, we 
should expect each stratum of pumice to be made up of analogous 
components to those produced during eruptions that preceded and 
followed it, indicating the same train of variations of activity, 
which is not the case. Geological evidence, so far as denudation 
has opened up to our examination the old remnants of igneous 
dykes and chimneys, leads us to conclude that igneous canals 
assume very irregular shapes, winding about where least resistance 
was offered to their extension, but nearly always assuming the 
form of a plate-like mass choking a fissure. Such fissure we know 
may have a horizontal extension of many miles. The opening or 
openings at the surface would be very local, and therefore the 
exit of the igneous matter would tend to take the form of a 
fan-shaped current with the point of orientation at the exit. Under 


126 Scientific Proceedings, Royal Dublin Society. 


such conditions the order with which differently exposed parts of 
the fissure’s contents reached the surface would be most complex, 
depending on a large number of collateral circumstances. The 
tendency will be to shade off sharp irregularities of composition, 
and render the magma more homogeneous. 

The Main Varieties of Volcanic Outbursts.—Whatever type of 
activity the volcanic outburst may have taken, we have only so far 
discussed secondary variations therein, and it now remains to 
explain what is the acting cause in different varieties of eruptions. 

It is necessary that we diverge from our train of argument to 
refer to some of the physical phenomena accompanying the relief 
from pressure of a superheated liquid. Sir G. B. Airy and Prof. 
Rankine! showed that in the explosion of a steam boiler the 
destructiveness was not due to the expansion of the steam already 
existing enclosed within it, but as soon as the pressure on the 
superheated water-contents diminishes, that liquid undergoes rapid 
and violent evaporation, until by such action the remnants are 
reduced to the normal boiling-point of the locality of the boiler. 
Mr. G. Biddle has demonstrated that, in a boiler containing steam 
and water at a pressure equal to four atmospheres, when the 
source of heat was removed, and the pressure suddenly relaxed, 
one-eighth of the whole liquid contents was immediately converted 
into the gaseous form. Prof. R. H. Thurston,’ who has lately 
worked at the same subject, has shown that although the energy: 
stored in the steam contained in a boiler is far in excess of that 
of the water at the same temperature, the amount, by weight of 
the latter, is often proportionally so much greater that it repre- 
sents an enormous amount of stored energy. He showed, how- 
ever, that as the temperature rose, the more the energy stored in 
the water approached that of the steam: at 50 lbs. pressure the 
ratio is 20 to 1; at 100 lbs., 14 to 1; at 500 lbs., 5 to 1; while 
at 7500 lbs. the two quantities become practically equal. At 
60 lbs. pressure, 1 lb. of steam equal 4 1b. of gunpowder ; but at 
very high temperatures, at which steam and water are equal to 
each other, they rival gunpowder. 


1 Phil. Mag., November, 1863. 
2 Trans. American Soc. of Mechan. Engineers, 1872; and Journ. Franklin Inst., 
December, 1872. 


Lavis—On the Structure of Rocks. 127 


These facts are of extreme interest in relation to volcanic 
activity. At the enormous pressure and temperature that an 
igneous water-bearing magma may exist, the dissolved water 
equals, or exceeds in energy the same weight of steam or gun- 
powder. We also see that the crater-forming and eruptive power 
will be in direct proportion to the amount of superheated water 
existing in the magma; and crateriform hollows of ten miles in 
diameter are not difficult of comprehension. In fact, it seems 
somewhat astonishing that such excavations are not far greater, 
when we think of the terrific energy that may be stored beneath 
us in the form of such enormous dykes as those great masses of 
_diabase in the region of the Hudson river. The great difference 
between the two conditions is, no doubt, that the water in the 
boiler is perfectly free to evaporate, whereas in an igneous magma 
it is molecularly scattered through the viscous mass, so that 
although the energy stored in equal quantities of water in either 
condition would be the same, the dispersion will be spread over a 
longer time in the case of the paste, due to retardation of escape 
in consequence of viscosity. 

In the author’s recent researches on the past and present 
eruptive phenomena of Vesuvius! certain important facts were 
brought out which it has been possible to confirm in a large 
number of instances in other volcanoes. When this volcano is 
in a state of chronic activity, with short intervals between one 
eruption and another, the violence with which the ejections take 
place is small compared with what occurs after long periods of 
quiescence. Thus, for instance, during the building up of the 
old mountain, and again during the last two to three centuries, 
we find that a very large portion of the products consisted of 
continuous masses of lava, whereas in the great explosions that 
excavated the gigantic crater of the Atrio del Cavallo, and which, 
from the interstratification of vegetable soils, and denudation 
marks, are proved to have occurred at long intervals apart, are 
characterized by deposits of spongy pumice, with a total absence 
of anything but fragmentary products. But in the above case we 
have not only geological, but even historical, proof; for we know 
that at least for many centuries before a.p. 79 this volcano had 


1 Quart. Journ. Geol. Soc., January, 1884. 


128 Scientific Proceedings, Royal Dublin Society. 


been apparently extinct, and that in the great Plinian eruption we 
had nothing but spongy fragmentary varieties of its usual igneous 
rock. The eruptions that followed the Plinian one occurred at 
diminished intervals, and so the more did their products approach 
in structure that of the lava of chronic activity, until, in the tenth 
century, pumiceous materials formed no longer, at any rate as far 
as the essential ejectamenta go, the products of these eruptions. 
To take another example, the precedents and whole history of 
which is pretty well known, namely, Monte Nuovo. We find 
that the main mass of the mountain is built up of pumice in 
various stages of comminution; capped, or covered, by more 
compact and crystalline scoria, or lava, fragments, which were 
only ejected at the last, when the voleano tended to pass into the 
chronic condition. We also know that such volcanoes as ‘T'omboro, 
Krakatoa, and others like them, after a long quiescence burst 
forth with an amount of violence to cause disturbances throughout 
our planet, produce ejectamenta that are always of pumiceous 
character. 

These facts, I think, give us the clue to the real sequence of 
phenomena which lead up to, and result in, the different varieties 
of eruption. Let us suppose that an extensive igneous dyke has, 
from some circumstances which will be discussed later on, become 
plugged at the exit on the earth’s surface. The part of the 
magma that retains a sufficiently high temperature will be 
gradually absorbing water; and as assimilation proceeds the 
tension of the magma will proportionally increase, and the tem- 
perature of the mixture reduced, so that in some cases this loss 
will gradually favour solidification of portion of the magma, 
-forming the crystals of the felspars, Amphibole, Biotite, and 
other micas, &c. Such a state of things will go on until one 
of two things takes place—either the loss of heat be such that 
the whole igneous mass solidifies, or, on the other hand, the 
tension overcomes the resistance, and an eruption takes place. 

Other things being equal, we should expect the violence of the 
outburst to be directly proportional to the length of contact of the 
igneous magma with water-bearing strata, or, in other words, the 
longer the quiescence the greater the violence in the subsequent 
eruption. 

The diffusion or solution of water through the igneous magma 


Lavis—On the Structure of Rocks. 129 


will diminish in a progressive manner as saturation increases. The 
amount that may be taken up is demonstrated by the enormous 
volumes that escape during an eruption. Were it possible to cal- 
culate the amount of vapour expelled during any great eruption, 
and to estimate the solid ejectamenta—also a difficult matter—these 
added together would give us the composition of the paste imme- 
diately before its expulsion, unless we have the level of the magma 
surface below that of the drainage-line of the country, in which 
case the vapour would be increased by the inpour from the porous 
walls of the chimney, and a pulverization of such water similar to 
the action of a spray apparatus, when the amount of vapour 
expelled might be enormously augmented. Such calculations 
have rarely been attempted. Cavalleri’ estimated that from 
Vesuvius, in 1856, during a period of eighteea months, pending 
which the strombolian state of activity had persisted, that no 
less than 407 millions of cubic meters of water had been ejected 
in the form of vapour. We may form an idea of the mass by 
imagining a lake 6 kilometers square, and 10 meters deep. I 
cannot form a just conception of the amount of vapour issuing from 
Vesuvius on the above occasion, but from a long and intimate 
acquaintance with this voleano during the last six years, it seems 
to me that the above calculation is greatly in excess of the truth, 
such a result being quite comprehensible when we take into con- 
sideration the almost insurmountable difficulties of finding suitable 
data to go upon. If we form a conception of 516,500 kilogrammes 
of water escaping every minute in the form of vapour from an 
aperture of four or five meters in diameter at the most, it certainly 
seems the feeble state of strombolian action would be out of the 
question. . 

It was also calculated’ that 22,000 c. meters of water were daily 
dispersed in the form of vapour by the lateral openings of Etna in 
the eruption of 1865, that is, equal to 2,000,000 c. meters, for 109 
days that that eruption lasted. This estimation, which, I believe, 
is that of Fouqué, certainly appears more reasonable than the 
former. 


1 Considerazioni sul vapore e conseguente calore, &c. ~Memoir read in the Accad. 
Fisio-medico-statistica di Milano, December 27th, 1856. 
2 Quoted by M. Ch.Vélain. Les volcans ce qu’ils sont et ce qu’ils nous apprenent. 
Paris, 1884, p. 45. 
SCIEN. PROC., R.D.S.—VOL. V. PT. III; L 


130 Scientific Proceedings, Royal Dublin Society. 


One is apt, however, to attach a greater value as regards 
quantity to volcanic vapour, from the peculiar molecular state 
which it assumes immediately on its escape, which is probably due 
to conversion of the steam into vapour, by the process investigated 
by Dr. Aiken. Everyone is aware that our breath in the hottest 
weather is converted into a white cloud when near the vapour of 
of HCl. Nevertheless, whatever value we may put upon the 
above calculation, we cannot do otherwise than comprehend the 
very large amount of water that may disengage itself from the 
igneous magma. 

In the case of a fissure whose upper limits are very far be- 
neath the surface, and suddenly extends thereto, we should expect 
the eruption to be less violent than were the magma in closer 
proximity ; since a large part of the energy of tension would be 
lost in the expansion in injecting the extension of the fissure. 

Conditions which may determine an Eruption. —In a large number 
of cases the gradual increase of tension in the confined magma may 
go on to the crisis of eruption. But in certain cases the intervention 
of collateral infiuences may anticipate such an occurrence. An in- 
crease of upward pressure from the main volcanic source, dependent 
upon secular cooling, tidal acticn (if such exists), or other causes, 
may be sufficient addition to the amount of tension already exist- 
ing to more than balance the resistance. A sudden lowering of 
atmospheric pressure may be sufficient in some cases to render the 
superincumbent pressure less than the tension of the igneous 
magma. It is known that, as the rainfall is increased in the 
season, the drainage level of a country reaches a higher line, and 
therefore the superincumbent pressure increases; and, vice versd, the 
superincumbent pressure diminishes during a drought, so that a 
sudden relief of pressure may be the metaphorical dust straw. 

The greater the height in a temporarily extinguished volcano 
the greater the weight, or, in an active one, the greater the pres- 
sure of the superincumbent column of lava above the drainage 
level.| We might therefore say, that as a permanent volcano in- 
creases in height its eruptions will diminish in frequency to increase 


* Let us compare the height of a column of phonolite paste of 100 (?) meters of Monte 
Nuovo with the column of heavier doleritic paste of Etna of 3300 meters, when we see 
that this is an important factor in modifying the eruptive character of a voleano. 


Lavis—On the Structure of Rocks. 131 


in power—a fact thoroughly borne out by experience. Under the 
same conditions, in a lateral opening of a very high voleano, such 
as Htna, the amount of lava will be greater as the chimney is 
higher above the outlet, since it will hold more. But beyond this, 
the amount of output will be more than that contained in the 
chimney above the level of exit, but also indirectly as the pressure 
of that amount is removed. When the lava pours out laterally 
from the chimney, its superincumbent weight, being removed, will 
allow expansion of the elastic matter below the level of exit, so 
that as this rises to establish a balance, lava will continue to pour 
out from the lateral outlet until total equilibrium is obtained. In 
this way the amount of lava spread over the surface will be much 
more than that contained in the chimney above the level of the 
exit. ‘This fact I have been able to verify on various occasions in 
the recent small eruptions of Vesuvius, which are in many ways 
more instructive than great ones on account of permitting near 
approach to be made. ‘This, I believe, will eventually be proved 
to be the true mechanism of lateral eruptions. As examples, we 
may compare the bulk of the lava products from the lateral craterets 
of Vesuvius and Htna. 

Conditions which determine the Extinction of a Volcano.— We have 
already seen how a dyke that has not manifested itself at the sur- 
face may solidify, and so divert igneous action to other localities. 
In the case of explosive eruption, the expansion that takes place in 
the magma increases its volume, in the form of a pumiceous froth, 
to such an extent that it occupies many times its original volume.! 
A large portion of this spongy magma escapes, leaving the fissure 
still filled to such depths as to the point where expansion would be 
prevented, choked, as it were, by this vesicular paste, which may 
even have solidified by the loss of heat in volatilization, and so 
may effectually have plugged up the exit. Some such process 
would really seem to occur in eruptions like those of Krakatoa. 
We have an illustration of this in opening a bottle of champagne 
well up, in which case more than half the liquid contents may 
escape in the form of froth. In the expanding magma there 
would be no distinct line of demarkation between the pumiceous, 


1 The volume of steam at 100°C. is 1696 times that of water at the same tempera- 
ture. 
L2 


132 Scientific Proceedings, Royal Dublin Society. 


or frothy portion, and the still continuous fluid mass beneath. If, 
from the want of supply from below, this does not rapidly rise 
and issue as a lava, it may go on gradually giving up its dis- 
solved water in that state, and by loss of heat may solidify and 
prevent, at any rate for some time, eruption at that particular 
voleanic vent. In the types of tranquil activity, either strom- 
bolian or in the case of occasional outpours of lava,’ we have three 
main agencies at work. In the first place, the aqueous matter 
contained in the magma will be dispersed, proportionally lowering 
the temperature. At the same time, the magma may be absorbing 
fresh water, raising it to its own temperature, and eventually con- 
verting it into vapour, which continues to escape at the expense 
of its own heat. Last, and probably least important, would be 
the conduction and convexion near the earth’s surface by the 
subterranean circulation of water. 

The Presence of Volatile Matter in Modifying the Structure and 
Composition of Igneous Rocks.—As has already been intimated, 
those grand explosive eruptions that burst forth after long in- 
tervals of complete tranquillity are characterized by an essential 
ejectamenta of vesicular structure and fragmentary state. On 
the other hand, chronic activity, even when it increases to the 
stage of paroxysmal outbursts, is equally well marked by the 
outflow of a continuous mass of igneous magma, or what is 
generally known as lava. The vesiculur rock masses, or scoria, 
that cover lava streams are, both in origin and structure, widely, 
though not completely, different from the pumiceous products of 
the first kind of eruption. These assertions hold true almost 
without exception in the case of basic rocks, and are exceedingly 
‘common even amongst the most acid ones. Most of the illustra- 
tions that will be brought forward have been chosen from among 
basic rocks, since, so to speak, crisis between a vitreous, fine, 
vesicular, and fragmentary state on the one hand, and a crystal- 
line compact continuous mass on the other, is easily attained, and 
is well defined. 


1 The paroxysmal eruptions of Scrope, Volcanoes, 1828 and 1862. 


Lavis—On the Structure of Rocks. 


Monte Somma Vesuvius. 


Puasse?  Introduc- 
tory explosive stage. 
Problematical. 


Puase I.—Chronic 
activity, outflow of 
leucitic basalt, lava, 
scoria, ash, &c. 


Puase IJ.— Inacti- 
vity, denudation. 


Puase IITIT.—Violent 
paroxysms, dwindl- 
ing into next phase. 

Production of basalt 
pumice and pumi- 
ceous scoria towards 
the end. 


Puasz IV.— Appa- 
rentreturn to chronic 
activity. Leucitic 
basalt lava (small in 
quantity). 


Puase V.— Inacti- 
vity, denudation. 


Puase VI.—Violent 
explosive eruptions. 
Production of basalt 
pumices. 


Paasr VII. — Less 
violent, dwindling 
into next phase. 

Production of leucitic 
basalt pumices and 
pumiceous scorias 
towards the end. 


Puase VIII.—Chro- 
nic activity, outflow 
of leucitic basalt 
lava. 


133 


Roccamonfina. Monte Vultura. Monte Nuovo. 
Same. Same. Introductory ex- 
plosive stage. At 
first, ejection of 
highly _ vitreous 
and microcrystal- 
line (excluding 
plutonic - formed 
minerals) pumice 
followed later by 
more compact and 
almost continuous 
outflow of Phono- 
lite. 
Same. Same. Apparent extine- 
Outflow of basalt, tion. 
Haiiyne basalt, 
and leucitic ba- 
salt. 
Same. Same. 
Same. Same. 
Production of leu- | Production of 
citic basalt pu-| MHatiyne _ basalt 


mice and pumi- 
ceous scoria 
towards the end. 


Same. 
(abundant.) 


Same. 


Same. 


Production of an- 
desitic ash in 
enormous quan- 
tities. 

Kruption of large 
quantities of an- 
desitic lava. 


pumice and pu- 
miceous  scoria 
towards the end. 


Same. 

(Abundant produc- 
tion of Hatiyne 
basalt lava.) 


Same. 


Semi - explosive 
eruptions of pu- 
miceous scoria, 
forming the pre- 
sent lake basins. 
Haiiyne __ basalt 
very similar phy- 
sically to Phase 
VIL., period 5 of 
Vesuvius. 


a 


134 Scientific Proceedings, Royal Dublin Society. 


From this Table we learn that a series of intermissions take 
place in the activity of a volcano; that following these inter- 
missions we have the production of fragmentary pumiceous ejecta- 
menta, which, by gradual stages, pass through a pumiceous scoria 
stage to that of true lavas. The striking resemblance between 
the phenomena of the three first-named volcanoes up to a certain 
stage cannot but strike the observer as very remarkable, and opens 
a wide field of investigation, for it is quite certain that similar 
stages in each of these volcanoes were not contemporaneous. 

The igneous magma, whilst confined below, may have under- 
gone partial crystallization before it reaches the surface. In that 
case, however rapid the ejection and cooling be, the ejectamenta 
will always contain those formed materials, as seems to have 
been the case with sanidine, amphibole, and, perhaps, other mine- 
rals in all?the pumices of Vesuvius, Mt. Vultura, Roccamonfina, 
the Campi Phlegrei, Ischia, &e. In case of the magma containing 
a large amount of diffused water, the sudden and rapid conversion 
of this into the gaseous state will immediately result in the con- 
version of the magma into a spongy mass, splitting it up into 
fragments of various sizes by the partial escape of the gaseous 
contents, and rapidly absorbing an enormous amount of heat. In 
consequence, the mass solidifies before time is given for the con- 
version of the vitreous into the microcrystalline or crystalline 
state, or, at the most, only allows such to take place imperfectly. 
As a result of the rapid solidification, many of the bubbles of gas 
are unable to escape from the mass, except where near the surface. 
We must remember that the change of pressure is not only from 
that of the original magma to that of the atmosphere at the 
earth’s surface, but the low pressure reached, by the ejectamenta, 
many thousands of feet, or even some miles upwards, to which 
height the materials are projected; and even if that were not 
sufficient, the rapid cooling by contact with the cold air in falling 
would complete the refrigeration. That such is really the case 
we have certain proof of in the preservation of organic and easily 
fusible substances of Pompeii. The actual physical structure and 
mineral composition of a pumice will depend on— 


(a) Composition of the original magma. 
(b) Pre-eruptive temperature of same, 


Lavis—On the Structure of Rocks. 135 


(ce) Amount of enclosed volatile matter. 
(d) Amount of pre-eruptive crystallization. 
(e) Rapidity of ejection. 

(f) Height of projection. 

(g) Temperature of the air. 

The ejection will take place at first with great rapidity, but 
will diminish as the tension in the whole unescaped mass is 
relieved. But beyond this the upper portion of the injected 
igneous magma column will be more exposed to aquiferous strata 
than that farther removed from the earth’s surface; and con- 
sequently the expansion, and the results dependent upon it, will 
be most marked in the portion of the magma near the surface, 
and also it is probable that that part richer in water will be 
lighter, and rise to the top of the column. This part having 
escaped, those portions that follow it will be hotter from di- 
minished loss of heat, from the less amount of diffused water 
it has raised to its own temperature, and also from the less water 
to be converted into steam: the latter will escape more slowly, 
and will reach a less height, all circumstances favourable to the 
slower cooling and less vesicularization of the magma. The con- 
sequence is, that we must expect more crystalline and denser ejecta- 
menta generally in larger fragments, which I have called pumiceous 
scorla. Should the eruption not terminate at this point, the con- 
ditions favourable to slow cooling, more complete crystallization, 
and continuity of mass, may proceed to such a point that the 
igneous magma may pour forth from the vent, forming lava 
streams of vast extent, so that years may be occupied in cooling, 
or the magma may be kept simmering in the volcanic chimney, 
presenting the characters of strombolian action. Monte Nuovo is 
a good illustration of the former case, although the lava hardly 
reached the point of flowing out as a continuous mass. The pro- 
gress of events, as above described, is fully borne out by the 
investigations of the physical structure and composition of rocks, 
whose mode of formation we can judge of by historical accounts, 
by collateral facts, and by analogy. I first discovered that an 
eruption of explosive type produced a deposit of pumiceous nature, 
divisible into three sections, at Vesuvius,' and I have been able to 


1 “Geology of Mt. Somma and Vesuyius,’’ &c., Q. J. Geol. Soc., Jan. 1884, 


136 Scientific Proceedings, Royal Dublin Society. 


verify the same facts at Roccamonfina, Mt. Vultura, Monte Nuovo, 
San Stefano, Ventotene, Ischia, and many other volcanoes, in at 
least a hundred different eruptions. In the second part of this 
paper I propose to bring forward typical examples from each 
locality in illustration of this. For the present, however, we may 
state the divisions as follow :— 


1. Hjection of vitreous froth, which rapidly solidifies, as pumice ; 
all the minerals that occur crystallized are of plutonic separation, 
as sanidine, biotite, amphibole, &c. 

2. Microcrystalline pumice, in which surface cooling has 
produced pyroxene and leucite. The amount of vitreous base 
diminishes as we reach the top of this division, and is replaced 
by formed material. 

3. The pumiceous ash-bed in which the cementing vitreous 
base is nearly all destroyed, so that cohesion has become so feeble 
that the formed matter separates, producing an ash composed of 
crystals and microliths. The difference is very similar to the 
results of crystallization of a salt in the form of large crystals by 
a slow process, or, in the preparation of the granular state, by a 
quick one, as table salt, pure Ferrous sulphate, and oxalic acid, as 
they are met with in commerce. 


The increase of the percentage of silica has the effect of 
rendering acid-rocks less easily crystallizable, just as the amor- 
phous form of sugar retards crystallization of other bodies with 
which it is mixed. For the same cause, the viscosity of the rock 
is increased, so that the escape of the enclosed gaseous bubbles 
takes place with greater difficulty; and, as a result, the pumiceous 
character is far more common amongst such rocks. 

Mode of Formation and Structure of Scoria.—This product, 
which is often erroneously grouped together with pumice, is that 
spongy variety of lava which covers or underlies a stream. When 
the magma does not contain sufficient volatile constituents to tear 
it asunder before it issues from the volcanic vent, it will pour 
down the slopes of the cone, giving up what remnants of aqueous 
matter are still dissolved within it. Should this be considerable in 
amount, and the temperature of the lava rather low, in basic 
examples we shall get an irregular broken-up cinder-like mass, 
that will continue to float on the surface, and cover it in some 


Lavis—On the Structure of Rocks. 137 


eases to a great thickness. Prof. Judd, who fully appreciates this 
fact, gives a striking example of this side by side with an equally 
interesting illustration of the opposite condition. On the contrary, 
should a basic magma be remarkably devoid of dissolved water, its 
surface will not be broken up, and it will assume forms like any 
other viscid body in movement. In the case of a water-bearing 
acid lava, the scoria surface will be much thicker, on account of 
the difficulty with which the gaseous materials escape in con- 
sequence of the viscidity of the paste; whilst in nearly non- 
aquiferous acid lavas the surface figures that result will be more 
marked, and more characteristic of an intensely viscous magma, 
as illustrated in the mammelon volcanoes, such as the islands of 
Reunion, Hawaii, the obsidian stream of Vulcano, or some of the 
central French groups. On the other hand, the Vesuvian lavas of 
1858 and 1872, as pointed out by Judd, are respectively typical 
of aquiferous and non-aquiferous magmas, which may be further 
illustrated by the trachyte of Monte Olibano, and the Lava del’ 
Arso of Ischia. 

From the mode of formation of scoria we must expect it to 
exhibit two very marked differences in structure and mineral com- 
position from pumice. In the latter the vesicular cavities are of 
all sizes, ranging down to the minutest dimensions, which are the 
most abundant and marked characteristic of pumice. This is due 
to the intermolecular separation of steam and its union sopra loco 
into vesicles of varying dimensions. In the case of the scoria, 
the gases are derived from the whole thickness of the subjacent 
lava, which, in rising in the mass, further unite together, so that 
the cavities are rarely of microscopic size, and may reach very great, 
dimensions; and unless the bubbles be of a certain size, the large 
area of their surface in proportion to their volume increases, so 
that the friction is so much that they could not rise in the viscid 
mass. In the case of pumice we have the vesicular structure 
developing in a complete or nearly vitreous magma, which is the 
principal cause of rapid solidification ; but in scoria the bubbles of 
hot gas that rise from the bottom, which, from being more pro- 
tected, is the hottest part, through a magma already far advanced 
in erystallization, would help to prevent or ward off the cooling of 
the surface. Besides, the scoria will cool slowly, resting as it does 
on the surface of a highly-heated mass. We therefore may sum 


1388 Scientific Proceedings, Royal Dublin Society. 


up by stating that pumice is filled by vesicles of all sizes, but 
mostly small, and approaches the vitreous state, whilst scoria only 
contains vesicles of large size, and approaches a crystalline structure. 
The ejectamenta during strombolian action is a true scoria, being 
dependent upon borrowed steam that rises in the magma column, 
and forms the vesicles. | 

In lavas the presence of vesicular cavities is no proof of the 
actual amount of original vapour, for the latter will be allowed to 
more easily escape in a microcrystalline mass, such as that of 1631 
of Vesuvius, which is a very compact rock, yet gave forth enormous 
quantities of vapour as almost to resemble the explosive type of 
eruption. The lava of 1858, which is rich in large leucite crystals 
and much interstitial glass, is a remarkable spongy structure, 
because its viscid nature prevented the escape of the few included 
bubbles of vapour, which, compared with others, was remarkably 
small in quantity in that eruption, affording compact types of lava 
surface. This escape of vapour may so separate the constituent 
minerals of a scoria surface as to leave it in a perfectly incoherent 
and pulverulent state. This I have seen in some of the trachytes 
of Ischia, and of the Solfatara (Monte Olibano). 

Another fact is, that lava as it pours out that portion which is 
nearer the surface will, in all probability, be the richest in water, and 
will produce a stream thickly covered with scoria. But asthe portion 
which comes from greater depths rises it will have been exposed 
for less time to aquiferous rocks, and in consequence, containing 
less water, will produce a smoother-surfaced stream. This was 
remarkably the case in the Vesuvian eruption of 1855 ;' the first 
streams that issued were much rougher than those at a later date. 

The conditions under which the composition of Igneous Rocks is 
modified.—One of the most vexed questions in geology is undoubt- 
edly that of the variation in an igneous rock, and more especially 
with regard to its chemical than its mineral composition. Space 
forbids here to enter fully into the theory of stratification of mag- 
mas, as represented by Von Richlhofen and others. No distinct 
division can be drawn between rocks derived from the most acid, 
and the ultrabasic magmas, showing that they can mix in all pro- 
portions. ‘Then again, whatever be the silicates we may fuse 


1 Memoiria s. Incend. Vesuvio, 1835, G. Guarini, L. Palmieri, and A. Scacchi. 


Lavis—On the Structure of Rocks. 139 


together, none of them separate from each other, however long they 
may be kept in the fluid state. Thirdly, all magmas may be 
looked upon as originally mixtures of fused oxides, some basic and 
other acid, it is true; but in either extreme types there is a certain 
amount of intermixture. We find such substances as the fats, 
mineral oils, chloroform separating from water, or mercury from 
either ; but we must remember that these incompatibles are built 
up of molecules, arranged on entirely different plans, which is not 
the case with the constituents of volcanic rocks. It may seem im- 
probable, but I feel sure that time will show that the active cause 
of various rock composition, at any rate, to a certain extent, will be 
proved to result from some chemical changes brought about between 
an isolated portion of an original common magma and the neighbour- 
ing rocks. Also the infiltration of saline solutions may result in 
the bases of the contained salts, combining with the silica, and 
liberating the original acids. The facts that support such a theory 
are certainly few, but also those that can be urged against it are 
equally so, and in most cases can be answered. ‘Thus, for instance, 
when great dykes, such as those that traverse the north of Kngland 
for miles, change little their composition ; and we hear, even at a 
most recent date, such an authority as Mr. Teall arguing against 
this theory ; it does seem in a tottering state. We must, however, 
remember that in most cases we are only able to examine a dyke, 
over any large area, in its horizontal extension ; but what is really 
necessary would be to investigate such sheets of rock in their verti- 
tical extension. There are examples in various parts of the world 
were dykes that extend to some distance show alteration in compo- 
sition as the rocks traversed change in character.'_ Von Buch and 
others have shown that in the Tyrol granite veins gradually pass 
into basalt ones, when traversing dolomitic limestone. The basalts 
of the Cyclopean Islands that are intrusive in a clay are most 
markedly altered where the dykes are thinnest. It has been shown 
that the great Whin-Sill has swallowed up beds roughly equal to 
its own thickness. On theoretical grounds we could easily under- 
stand an acid lava taking up limestone with its impurities, and 


1 N.S. Shaler. ‘‘ Propositions concerning the Classification of Lavas, considered 
with reference to the Circumstances of their Extrusion,’’—Anniversary Memoirs of the 
Boston Society of Natural History, 1880, 


140 Scientific Proceedings, Royal Dublin Society. 


becoming more basic, and thus reducing its temperature whilst it 
became more fluid. If this were the case we can understand that 
further action on limestone would be limited by saturation of the 
magma with lime and its low temperature. It therefore seems 
that we should look more to granite and its derivative as fuses of 
limestones than to basic rocks. Why should not the basalts of 
Mull be the result of the contact of the granites with the under- 
lying limestones? I have brought the subject forward, not with 
the intention of offering new evidence, but to again direct attention 
to such an important branch of vulcanological science. 

Let us now turn our attention to the mineral composition of an 
igneous rock. Any given magma will produce rocks of the most 
varied character, according to the conditions under which consoli- 
dation takes place. Thus, for instance, a given dyke of magma 
might be a granite near its origin, higher up its sides or whole may 
be pitchstone, and its centre a liparite or porphyry, whilst at the 
surface it would present itself as vitreous pumice and ash, an 
obsidian or a quartz trachyte. It has been observed that granite 
veins branch out, and the ramifications may assume the type of 
felsite, which is of course dependent on the more rapid cooling, just 
as in the case of the salband. Again, we have a series of grada- 
tions from a true leucitic basalt, such as the recent lavas of Vesuvius 
to a sanidine porphyry, to a highly erystalline syenite containing 
leucite, but more commonly nepheline in the rocks, composing the 
ejected blocks. The generalization based upon the geological ages 
being characterized by different types of rocks is false, and is no 
doubt due to the depth to which denudation has extended. It isa 
general fact that the slower the cooling takes place the more perfect 
will the cystallization be. This we have already spoken of when 
treating of the difference in the amount of gaseous constituents in 
a magma which, by bringing about great rapidity of cooling in 
explosive eruptions, makes the products tend to an amorphous 
rather than a crystalline condition. One remarkable fact well borne 
out by the lavas derived from the different eruptions of Vesuvius 
is that the size of the crystals are much greater in the little oozing 
forth of a small quantity of lava from the crater than in the great 
outpoors. This will be evident, as in the first case the lava has 
been in a state of simmering in the upper part of the chimney for 
a long time, and will have been loosing its heat in a very gradual 


Lavis—On the Structure of Rocks. 141 


manner, so that such minerals as leucite and pyroxene at Vesuvius, 
or the latter mineral at Stromboli, are able to gradually increase in 
size and perfection, which will proportionally diminish the ecrystal- 
lizability of the remaining vitreous matter. Professor Samuel 
Haughton' has shown that the remaining paste consists of a very 
fusible basic glass with an approximate composition of 2RO, 810? 
containing much iron protoxide. On the other hand, a large supply 
of lava brought up from below with considerable rapidity has little 
time for the growth of individual crystals, but the whole mass 
undergoes a microcrystalline change until no, or very little, vitreous 
matter remains to feed the further increase of individual crystals. 
We have a parallel in such a case as the following :—If we make a 
solution of some salt very soluble in boiling water, but very slightly 
so in cold, and we cause such a solution to cool moderately quickly, 
the salt will separate itself in a granular crystalline state; but if 
such cooling be made to take place gradually during many days, 
very fine, perfect, and large individuals will replace the granular 
types. Now, when a microcrystallization takes place, it will so 
separate the remaining vitreous material that even under the 
microscope little will be discernible, so that it is very difficult to 
detect it or appreciate its amount. But where suitable conditions 
favour the growth of large crystals in a similar magma, the vitreous 
matter that remains will be more concentrated, and therefore more 
apparent both to the naked eye and under high magnifying powers. 

The histological character of any cooled magma, with regard 
to its mineral components, is a question of profound interest, 
which, up to the epoch of the attempts of artificial reproduction 
of different types, aided by microscopical research, remained a 
very obscure subject. When we have to deal with the fused com- 
ponents of any single mineral in a pure state, the researches of 
Messrs. Fouqué and Lévy demonstrated that, so far as laboratory 
experiments go, the critical point of crystallization is near that of 
the fusing-point of a mineral. We should, therefore, expect that 
in a leucitic lava, the leucite would be first to separate as crystals, 
to be followed by felspars, and last by pyroxene. It is a well- 
known fact that some of these crystallized simultaneously. This 


1 << Report on the Chemical, Mineralogical, and Microscopical characters of the 
Lavas of Vesuvius from 1631 to 1868.’’—-TZrans. Roy. Iv. Acad., vol. xxvi., p. 141. 


142 Scientific Proceedings, Royal Dublin Society. 


is most strikingly illustrated by a coarse leucitic lava exposed near 
Orchi, on the voleano of Roccamonfina, where leucites, some two 
or three centimeters in diameter, enclose many large and perfect 
erystals of sanidine and pyroxene, which, in some cases, are 
entirely enveloped, or protrude a short distance from their surface. 
We might, with such a series of contradictions, feel inclined to 
give up further experiments in the laboratory. Before, however, 
let us compare what has been done by the chemist, and see if it is 
borne out by rocks as presented to our observation by nature. We 
will commence by recalling the interesting researches of Sir James 
Hall,1 who noticed that if such igneous rocks as whinstones and 
basalts were fused and cooled quickly, a glass resulted; but by 
keeping them near fusion-point (recuit of modern French authors), 
or allowing them to cool slowly, a crystalline structure resulted. 
These experiments were followed up by Gregory Watt,’ who went 
a step farther, and demonstrated that the sp. gr. increased in pro- 
portion to the prolongation of cooling. 

The absence of microscopical research prevented any important 
inferences from being drawn from these early experiments, and it 
was not till the investigations of Daubrée, Hautefeuille, Freidel, 
Sarasin, Fouqué, Michel Lévy, and others that much advance 
was made. ‘These authors® found that by recwit, more or less 
prolonged, the following minerals might be obtained from their 
fused chemical components :—Peridote, pyroxene, nepheline, leu- 
cite, triclinic felspars, mellilite, gehlenite, and sphene; whilst 
from mixtures not corresponding to the mineral obtained the 
following were prepared :—Tridymite, oxides of iron, and perov- 
skite. Many of the first group are obtainable from indefinite 
mixtures. It is this latter point that is undoubtedly the true key 
to this enigma of the different results in nature, and in the 
laboratory. 

It will be convenient to take up the principal rock-forming 


1 «¢ Experiments on Whinstones and Lava, 1798 ;’’ and also Trans. Roy. Soc. Edinb. 
1805, vol. v., pp. 8 and 56. 

2 “ Observations on Basalt and the Transition from the Vitreous to the Strong Tex- 
ture which occurs in the gradual Refrigeration of the Melted Basalt, with some Geolo- 
gical Remarks.’’ —Phil. Trans., 1804, p. 279. 

3 Encycl. Chimique, tome ii., Metalloids. Ie Appendice. Reproduction Artificel 
des mineraux e roches. L. Bourgeois, p. 10. 


Lavis— On the Structure of Rocks. 143 


minerals one by one and compare their occurrence in nature with 
their reproduction artificially. 

Peridote was obtained,’ amongst other methods, by recwit, at a 
white-red heat, of the elements of a basalt, exactly identical in all 
characters with what occurs in nature. This mineral occurs 
naturally in two forms. The first are irregular nodular masses, 
found as bombs, or entirely enveloped in the lava. From their 
large size they must have required a long time to crystallize, which 
took place in all probability before the extrusion of the magma. 
They, no doubt, resulted in some cases by actual crystallization 
from the igneous matter; but, I believe, by far the larger part 
are nothing more than a very advanced metamorphism of a 
- dolomite; for amongst the ejected blocks of Monte Somma or 
Roccamonfina we may obtain all gradation between the original 
sedimentary rocks and these masses of pure olivine. The most 
common form, in a petrological point of view, is the disseminated 
grains that often go to make up a rock. These are seen to be 
nearly always one of the first conversions of the amorphous paste 
into formed material. Yet the actual conditions suitable to its 
crystallization are not quite clear; for we find lavas ejected from 
the same volcano abound with it sometimes, and at others it is 
quite difficult to find. So far as my observations go, it favours the 
basic rocks of fine-grained structure, and especially those that 
have cooled quickly from a very high temperature, although it 
seems capable of increasing in size during slow cooling from a 
very high temperature, in consequence of the lava stream being 
very deep. ‘This is the case with some very coarse lavas of 
Vesuvius, such as that of Pompeii and Cisterna, which contain 
some crystals a centimeter long. 

Amphibole—This mineral has baffled all the attempts of the 
chemist to prepare it artificially otherwise than as a sublimation. 
Whenever its elements were fused separately, or a complex mix- 
ture, was fused, the only product was its ally—pyroxene. Our 
entire acquaintance with amphibole indicates it as a mineral crys- 
tallized under pressure, and probably from an aquiferous magma. 
Its continual occurrence in syenites and allied rocks show it to be 
easily crystallizable under the conditions which these rocks came 


1 Fouqué and M. Lévy. Bull. Soc. Min. 1881, t. iv., p. 275. 


144 Scientific Proceedings, Royal Dublin Society. 


into existence. I have found it in basic pumices continually 
accompanying orthoclase (of which we shall speak next) in the 
more vitreous and early stage of the explosive eruption ejecta- 
menta of Vesuvius, Roccamonfina, &e. In the later stages of the 
same eruption it does not appear to have increased in size or 
abundance, whilst it is often enveloped in pyroxene; and this 
latter species is spread throughout the mass, increasing in propor- 
tion as the rock approaches the lava type. This is the more. 
remarkable, because we know that amphibole is more fusible than 
pyroxene; whereas, if we exclude change of pressure, &e., it 
should have crystallized later. This fact alone is quite sufficient 
to disprove any relationship between the fusing-point of a mine- 
ral and its order of crystallization. Where amphibole is found 
in a lava, we have evidence that it existed as such before the 
eruption of that material. It is not at all an uncommon mineral 
lining vesicular cavities; but it there shows itself to have been 
deposited by sublimation, which is borne out by its discovery under 
similar conditions in some furnace scorias.' 

Orthoclastic felspar was obtained by M. Stanislas Meunier? 
by fusion and subsequent recwit of acid rocks. The product, 
however, only consisted of crystalline concretions, having the 
composition of orthoclase. Microliths only rewarded the efforts 
of Messrs. Fouqué and M. Lévy® after a long recwit of eight 
days. These facts are thoroughly borne out by the basic pumices. 
Those that were cooled very rapidly in the first eruptive stage 
exhibit large, well-formed crystals of sanidine associated with 
amphibole, showing the similar conditions under which the two 
minerals were formed.’ In the latter stage of these eruptions the 
large crystals have not increased in number or size (?); but from 
the slower cooling a few microliths have formed. Another proof 
is to be found in the occurrence of fragments of a porphyritic 
rock, which is only the pumice magma that, in some outlying 
fissure, has cooled under pressure, and in some cases undergone 
secondary alteration. ‘This shows the sanidine crystals still larger 


1M. L. Bourgeois, Op. cit., p. 119. - 

2 Comptes rendus, 1880, t. xc., p. 1009. 

3 Comptes rendus, 1878, t. Ixxxvil., p. 700. 

4 Whether these are really orthoclastic is generally a very difficult matter to deter- 
mine. 


Lavis—On the Structure of Rocks. 145 


and more perfect. This rock may be traced by gradations to a 
syenite-like rock, in which the amorphous magma is entirely con- 
verted into formed matter. In the basic lavas, which are identical 
in composition with the above pumices, the sanidine only occurs as 
very small crystals or microliths, as the magma rising quickly to 
the surface has little time to partially crystallize under pressure. 
On the contrary, after extrusion, the lava will cool very much 
slower than the pumice, so that the prolonged recwit will be highly 
favourable to development of orthoclase microliths, and even small 
crystals. These facts are well borne out by Vesuvius in its pumices 
and modern lavas, whilst the outflows of Phase IV., following 
immediately on a pumiceous phase, hold an intermediate place 
with regard to their monoclinic felspars. It is not an uncommon 
thing in basic pumices to find sanidine! crystals eroded, enclosed in 
others, which in turn may exhibit eroded surfaces, and again be 
enclosed in a third crystalline shell with well-defined facets. The 
orientation of each crystal being different from that which it coats, 
or is covered by. It is evident, therefore, that this mineral must 
have undergone a series of vicissitudes which must have taken 
a far longer time than was occupied in the eruption and cooling of 
this product of an explosive eruption, and must have required 
more quietness than could occur in the expansion and ejection of 
pumice. This latter example I take to be an important argument 
in favour of the hydro-thermal, or plutonic, formation of ortho- 
clastic felspar in a magma cooling under great pressure. Another 
fact also of deep interest is the very extensive replacement of 
sanidine in the Vesuvian pumices of Phases III. and IV., by 
leucite in those of Phase VII. and the lavas, as these are the two 
principal competitors for the potash. If the granite and syenites 
of the Val di Fassa, and the latter of Skye, described by Scrope 
and Geikie respectively, are really subaerial expansions, which 
I doubt, we must suppose them to have been nearly completely 
crystallized before eruption. Porphyries, no doubt, are erupted 
granites, which had undergone much crystallization before their 
extrusion. Hyen in the most vitreous rocks, such as the obsidian 
and obsidian pumice of Lipari, where the latter, although, as a 


1H.J.J.L. ‘*Geology of Mt. Somma and Vesuvius,”’ &. Q.J.G. S., Jan., 1884, 
[Ds file 
SCIEN. PROC., R.D.S. VOL. V. PT. 111. M 


146 Scientific Proceedings, Royal Dublin Society. 


whole, a highly vitreous mass, contains large crystals of sanidine 
scattered through its mass. 

Triclinie felspars.—Other felspars, such as labradorite,’ were 
produced by a recuit of some days; but large crystals, such as 
are met with in the Htna lavas, do not so far seem to have been 
obtained. Such a result is easily explicable, when we are informed 
that to produce a microlith some days are required, whereas we 
know that even after the expulsion of the lavas of Htna many 
months or years are requisite for their cooling, so that recwt may 
be prolonged far beyond the limits within which we can experi- 
ment. If a large stream of lava, such as issued from Htna in 
1669, be examined, it will be found that even that which was 
cooled immediately contains crystals of labradorite, which indi- 
cate the plutonic origin of that mineral, or that the magma had 
been undergoing a prolonged vecuit in the upper part of the chim- 
ney. Specimens taken from the centre of some of the thicker 
parts of the stream far from its source, and which must have been 
long in cooling, we find the crystals of that felspar therein con- 
tained have attained greater dimensions, thereby indicating that 
under favourable circumstances this mineral may undergo further 
growth after extrusion of the lava. A similar occurrence I have 
noticed at Vesuvius. At Cisterna is a gigantic lava stream that 
is known to be more than half a kilometer broad, and its depth 
beneath is unknown, although it is quarried to a depth of twenty 
meters, at a distance of more than ten kilometers from the original 
eruptive axis of the mountain. Now, of ali the lavas of Monte 
Somma this is the most extremely crystalline one, all its constituents 
being of very large size, and practically all the amorphous paste has 
- passed into a crystalline condition. So far as is known, this is the 
greatest outpour that ever occurred from this mountain ; and, no 
doubt, in consequence of its enormous thickness, being unrivalled 
by any modern stream, a very long time must have been occupied 
‘in its cooling, conditions highly favourable for the production of 
a coarse structure. When small streams dribble from the crater 
after prolonged strombolian action, the structure also is often 
very coarse, as the part of the lava column in the chimney has 
been gradually loosing its heat. Anyone who visits Monte 


1 Fouqué and Lévy, Comptes rendus, 1878, t. Ixxxyil., p. 700. 


Lavis—On the Structure of Rocks. 147 


Somma may have noticed that most of the lavas along its crest 
are coarse-grained, whereas most of those near the toe are fine- 
grained. ‘The reason, as at present with Vesuvius, is obvious. 

From the almost impossibility of artificially producing the 
felspars, Delesse,' Daubrée,’ and Sorby,’ assert that they must be 
the result of hydrothermal origin. Whether the actual presence 
of water is necessary directly, or only as the means of increasing 
the tension and pressure in the magma, seems at present un- 
answerable. 

Anorthite was the most easily obtained, and corresponded in 
characters exactly with the same mineral in lavas that have con- 
solidated near the surface. This mineral, as is well known, is 
rarely met with in true plutonic rocks. 

Quartz appears never to have been produced artificially, ex- 
cept from solution in water of silicates of a glass at a high tem- 
perature and pressure by Daubrée; and from the abundance of 
fluid cavities seems to be the result of (in rocks) hydrothermic 
origin under very great pressure. 

Leucite, although a mineral of local occurrence, is of deep 
interest to the petrologist. It has never been met with amongst 
furnace slags, except as a sublimation. M. Hautefeuille* obtained 
measurable crystals by fusion of the components of leucite in 
vanadate of potash. Fouqué and M. Lévy’ obtained by igneous 
fusion and recuit without a flux. With the components of leu- 
cite alone it was impossible to obtain the mineral, and this could 
only be done by taking equivalent components of a mixture of 
that mineral and pyroxene. ‘This is a most important fact that 
again helps to clear away the veil of mystery which overhangs 
the genesis of many silicates. Most substances can be obtained 
crystallized by one or more of four principal methods—from sub- 
limation, by fusion, by evaporating a solution, and by cooling 
down a solvent. The necessary temperature is highest for the 
first, less for the second, and very much the lowest for the third 
and fourth. Sulphur, to be obtained in crystals from fusion, 


1 Bull. Soc. Geol., 1857 and 1858, vol. xv., p. 728, 757, 769. 

2 Rapport sur les progrés de la geologie experimentale, 1867, pp. 63 and 84. 
3 Brit. Assoc. Reports, 1880. 

+ Annales Scient. de l’Ecole norm. sup. 2nd’series, vol. ix., 1880. 

> Comptes rendus, 1878. t. Ixxxyii., p. 961. 


148 Scientific Proceedings, Royal Dublin Society. 


requires a temperature of at least 115° C., whereas by solution in 
carbon bisulphide we may obtain crystals far more perfect at the 
ordinary temperature of the air. We must, therefore, look upon 
leucite as dissolved in a medium which is liquid at a bright red 
heat, and only gives up this, as well as other minerals, by a lower- 
ing of temperature, in the same way that a mixed boiling satu- 
rated solution of salts of various solubilities separate out (far 
below their fusing-point) as the solvent cools. Precipitation 
might also depend upon withdrawal from the mixture of one 
or more of its elements for the formation of a mineral that has 
already commenced to separate. If we take a solution of mercuric 
biniodide in a solution of potassic iodide, and add some substance 
that will seize upon the iodine in the latter salt, such as argentic 
nitrate, we have an immediate precipitate of the mercuric bin- 
iodide proportional to the amount of potassic iodide broken up. 
Stoppani gives the example of nitrate of potash dissolved in water, 
which is precipitated immediately if alcohol is added.t The fact, 
therefore, of leucite crystallizing far below its fusion-point proves 
the solution of that mineral in that glass or some other. This 
would explain the crystallization of the two minerals simultane- 
ously, as at Roccamonfina; for as the lowering of temperature 
took place in the magma as the pyroxene crystallized out, the 
remaining would become supersaturated with leucite, which 
would have to separate. We might possibly imitate this con- 
dition in freezing a saturated solution of a salt in water. It is 
also possible that the leucite does not form until the potassic 
chloride in the magma has been broken up, and the HCl has 
escaped in the vapour. 

In the formation of rocks we have a process of fractional ex- 
haustion of the original amorphous medium, in which secondary 
combinations can hardly be conceived to take place until some 
portion assumes definite crystalline form, the kind of which will 
depend upon the elements that enter into the composition of the 
mixture, and the train of conditions which that undergoes in 
passing from a higher to a lower temperature. Starting, for 
example, from an amorphous mass of fused silicates, we may 
suppose that condition 1 is favourable to the formation of mineral 


1 Corso di Geologia, vol. ii1., p. 131. 


Lavis—On the Structure of Rocks. 149 


B, but as this separates, A can no longer remain in solution, so 
this also separates until the magma is deprived of as much of the 
elements as these minerals A + B can take up, and the glass is 
then suitable for the growth of C which comes next, and in its turn 
may be followed by D, and so on. The resulting rock will be 
composed of the minerals A+ B+C+D, &. Let us again start 
with the same magma, and suppose that condition 2 comes into 
play, which is favourable to the formation of A, which will separate, 
exhausting the magma to a point that it is suitable to the forma- 
tion of X, in preference to any other, which now carries the 
exhaustion on, till the magma approaches Y in composition, which 
in turn continues the exhaustion, till the unformed material is 
- suitable for the crystallization of D. We should thus obtain a 
rock containing the minerals A + X + Y + D, both of which would 
be identical in ultimate chemical composition. Now, condition 1 
may have been favourable to rapid expansion, and eruption such 
as pumice results from, whilst condition 2 we may take to represent 
the gentle outflow of lava. The reality of this somewhat rough 
illustration will be more apparent if we compare the vitreous 
pumices of Phases III. and VI. of Monte Somma, in which leucite 
is absent, and sanidine abundant, with the highly leucitic basalt 
lavas of the same volcano, in which sanidine at the most is a very 
unimportant element, remembering at the same time the practi- 
cally complete identity in chemical composition of the mass of 
either. An interesting point in connexion with this is the fact that 
Messrs. Fouqué and M. Lévy obtained a leucitic rock from fusing 
together orthoclase and biotite. Prof. Samuel Haughton! was, I 
believe, the first to treat the mineralogical composition of a lava 
on the principle of the exhaustion of the element of the magma or 
paste, the different minerals competing for certain oxides which 
are necessary for their formation, so entirely devoting himself, with 
remarkable ingenuity to the chemical side of the question, but 
disregarding the physical, which, however, hardly entered into the 
scope of the subject discussed. We must, however, not forget the 
varying conditions under which cooling, in an igneous rock, takes 
place, such as time, pressure, water, volatile acids, and their corre- 
sponding salts, which must be most important elements in modify- 


Op. cit. pp. 68 and 188. 


150 Scientific Proceedings, Royal Dublin Society. 


ing the ultimate mineralogical composition of the solidifying rock. 
Let us take two groups of the mineral elements of Vesuvian 
essential ejectamenta; we have leucite antagonistic to amphibole, 
nepheline, and mica, all competing for the potash. Now, in the 
pumices of the great explosive eruptions of Phases III. and VI. we 
find amphibole, sanidine, and biotite using up the potash, and 
being the principal crystalline ingredients, whereas in the lavas 
that cooled under quite different conditions we find these minerals 
reduced to a minimum, whilst all the potash has been seized upon 
by the leucite, and sometimes a little nepheline. How can we 
account for such phenomena, otherwise than in change of condi- 
tions P Again, we find pyroxene, antagonistic to olivine, amphi- 
bole, and biotite, competing for the magnesia. Again, in the 
Vesuvian pumices, amphibole and mica prevail, as these had pro- 
bably formed under great pressure, whilst in the same pumices that 
escaped more slowly, and in the lavas, itis the pyroxene that mono- 
polized the magnesia. We know that olivine (?), amphibole, and 
biotite are met with in their greatest perfection in plutonic rocks, 
whilst pyroxene is remarkably characteristic of rocks slowly cooled 
near the surface, and under low pressure. ‘The fact of the former 
of these having resisted all attempts at artificial production points 
to conditions which have not yet been adopted in the laboratory, 
whilst leucite and augite are produced with ease and certainty. 
We therefore must conclude that antagonism of mineral species in 
crystallizing from a medium depends not only on the composition 
of that medium, but also of the surrounding physical conditions. 
Prof. Haughton’ admits that, according to his theory, olivine ought 
to prevail, as it has only to contest for iron and magnesia, whilst 
pyroxene, amphibole, and biotite, are weakened in the additional 
fight for lime or alumina. He attempts to explain this by a 
theoretical principle which he calls that of minimum paste, which 
would not have been requisite had the physical conditions been 
taken into account. Again, this theory in its incomplete form is 
proved insufficient by the joint author, Prof. H. Hull,’ in the same 
memoir, although it was undoubtedly a great step in the direction 
of an important principle. 


1 Op. cit. 2 Op. cit., p. 141, 


Lavis—On the Structure of Rocks. 151 


M. Bourgeois' accounts for the crystals of pyroxene in leucite 
to be the crystallization of the glass cavities. This is obviously 
not the case, for the following reasons :—In the leucites of Rocca- 
monfina and Vesuvius the crystals of pyroxene entirely traverse, 
project their ends on each side, whilst the leucite material is 
accurately moulded on the crystal facets of the pyroxene, which 
form leucite could not give to a glass space. Besides, many 
pyroxene crystals bear no relation whatever, either in size or 
position, to the remaining cavities, which themselves do not show 
such crystallization. Their crystals are often imbedded in the 
leucite mass, and project into a glass cavity, the latter portion 
being no thicker than the former, which was entirely enveloped in 
the leucite mass. Where much growth of crystals in glass cavities 
take place, that portion surrounded by the vitreous paste of the 
glass cavity should have increased in size. That the artificial 
conditions employed in the laboratory fairly represents the natural 
ones in the production of leucite there exists little doubt; the varia- 
tions in temperature were just such as we meet with in the forma- 
tion of that mineral at Vesuvius. Besides, the two minerals were 
identical in crystallographic characters, both externally and inter- 
nally, as seen by polarized light, and also the great resemblance 
as exhibited in the strata of glass cavities. 

That leucite may separate or any rate increase in size, after 
expulsion of lava, seems to be demonstrated by the observation of 
Scacchi,” that the scoria of the lava of 1855 did not contain large 
crystals, and that in the lava the distribution of them was irregular, 
which seems to show that recut at least increased their size. ; 

In describing leucite I have considerably erred from the direct 
road, led on by the train of argument, based principally on the 
physical and chemical properties of this interesting mineral. 

Biotite, though commonly met with in volcanic rocks, could 
not be obtained as a distinct form by Messrs. Fouqué and M. 
Lévy. In lavas we generally meet with this mineral in large, 
well-formed crystals, as also in pumices. In some basic pumices 
of Monte Somma (Phase III.) very beautiful hexagonal micro- 


1 Encycl. Chim., vol. ii., Metalloids, [°° Appendice. Reprod. Artif. des Roches, 
p. 212. 
2 Guarini, Palmieri, Scacchi. Mem. Sul. Incend. Vesuy., 1855, p. 152. 


152 Scientific Proceedings, Royal Dublin Society. 


lithic plates, and small crystals may be seen scattered throughout 
the magma, and often enclose crystals of orthoclase. In the more 
highly crystalline pumices and lavas this mineral occurs generally 
as well-formed crystals. Although it is not very uniform in its 
occurrence, I am disposed to regard it rather as pre-eruptive in 
formation, or, at any rate, in part. 

Magnetite is another mineral that cannot be obtained by 
simple fusion, but requires solution in a fused medium, from 
which it separates during cooling within a great range of tem- 
perature,’ provided the formation of other minerals renders the 
magma supersaturated, from time to time, with this oxide, so that 
various crops of crystals may result, forming so many periods of 
consolidation. ‘This is the only way we can explain its formation 
as with quartz, leucite, &c. Scheerer pointed out long ago 
the granite-forming minerals separated inversely to their fusion- 
points. 

Pyrowene, as well known, is a common product in furnace 
slags, and is easily obtained by simple fusion of its elements with 
a very short recwit. Messrs. Fouqué and M. Lévy found it to be 
produced in a microlithic condition after a few moments’ vecwtt, 
and prolonging this a little, fine crystals, such as are met with in 
voleanic rocks, were obtained. Such a fact convinces us of the 
extreme rapidity with which basic pumices, at any rate, must 
have passed from the fluid to the solid condition, as in many of 
the Italian basic volcanoes the first products of some of their 
explosive eruptions were practically without even microliths of 
pyroxene, striking examples of which are to be met with in the 
deposits of Phase III., period 1, and Phase VTI., periods 1 and 38, 
of Monte Somma. ‘The above-mentioned authors found the 
limit of temperature rather wide in which this mineral crys- 
tallized, which accounts for its inclusion in others that separate 
at rather higher temperatures. ‘The pyroxenic glass seems to be 
the principal medium in which the other silicates and oxides are 
dissolved in basic rocks, whereas an acid felspathic glass seems 
to perform the same function in acid ones. 

We may regard the magma from which results an igneous 
rock as a variable mixture of acids and bases, as pointed out by 


! Bull. Soc. Géol, 2° serie, tom. iv. page 478, 


Liavis—On the Structure of Rocks. 153 


Abich. Now, as consolidation takes place, great excesses of 
either, especially the feebler ones, such as magnetite, are com- 
pelled to separate; and as the rock completes its crystallization, 
the excesses of either form the last crystals, unless the rock 
suddenly cools before all the vitreous matter has been converted 
into formed material. ‘Thus,in the acid rocks we have quartz, and 
in the basic ones magnetite, being the last formed minerals, 
although the two most infusible of rock-forming minerals, which 
alone is sufficient to demonstrate that fusion-point has little or 
nothing to do with the order of separation of the minerals. We 
should therefore be more justified in determining whether a rock 
should be regarded as acid or basic by its microscopical structure, 
than by adopting 60 per cent. of silica as rigidly dividing the two, 
since the different bases vary much in alkalinity, and combining 
proportions, and a magma containing 60 per cent. of silica, might 
give an acid or an alkaline reaction, according to the quantities of 
different bases it contained. 

Limit of space prevent further consideration of the different 
mineral species which go to make up igneous rocks ; the above, being 
most common, are sufficient to indicate the line of argument 
followed out. Before, however, quitting the subject, there is one 
more point worthy of our consideration in relation to the separation 
of mineral species from a solvent. Different species have been 
easily obtained from fusion of their components in a saline sub- 
stance, such as a chloride or sulphate. Thus, for instance, M. 
Lechartier’ obtained pyroxene in crystals, a centimeter long, by 
fusion for a couple of hours in calcium chloride, or sodium sulphate. 
In the same way wollastonite, apatite,” and many other minerals 
have been obtained by EH. Belmen as very perfect crystals from 
solution in fused chlorides, and other salts, such as vanadates. 
These facts go to confirm what has been said about the solution of 
the more infusible silicates in the more fusible ones, and at the 
same time may account for the occurrence of some minerals that 
are eruptive, or post-eruptive, in time of their formation. The 
large amount of sulphates, but especially chlorides, that are vapor- 


1 Comptes rendus, 1868, vol. Ixvii., p. 41. 
* L. Bourgeois, Eneycl. Chim., vol. ii., Ie’ Appendice. Reprod. Artif. des Roches, 
p- 10, 


154 Scientific Proceedings, Royal Dublin Society. 


ized during an eruption is hardly credible until a few facts convince 
us that such is the case. I have seen fumarole chimneys having 
in a short time their whole interior glazed by a mixture of chlorides, 
one to three centimeters thick, and from the intense heat as trans- 
parent as an ice covering, which was, without doubt, the result of 
sublimation, and not decomposition, as the rocks upon which it was 
deposited were quite unaltered. Another proof of the large amount 
of saline substances ejected by a volcano is the quantity met with 
in the falling ashes during a lava eruption. The outburst in 1872 
produced an ash asserted by Prof. Palmieri' to be poorer in soluble 
constituents than any other since 1855, yet it contained from 4 to 
9 per cent. of saline matter, chiefly sodic chloride. As this erup- 
tion was lateral, the principal part of the ash was derived from the 
crater edges and chimney walls, which would tend to lower the 
amount of soluble portion. 

It was observed in the eruption of 1855° that the alkaline 
chlorides were only evolved sometime after the lava had been cool- 
ing—that is to say, saline crusts only formed around the fumaroles 
at a late date; and I have noticed the same thing. Scacchi sup- 
posed that it may be a spontaneous rise in temperature in the lava 
in cooling, similar to that developed in phosphate of lead, nitrate 
of copper, or argentic’ iodide when passing from the amorphous to 
the crystalline condition. Or again, to their early union with 
other elements of the lava. This may possibly be so, the combi- 
nation being broken up by a lowering of temperature (?), leaving 
the chlorides free to besublimed. It seems to me that the chlorides 
must be continually escaping, but that they are not deposited until 
the scoria and fumarole sides are cooled enough to allow such to 
occur. The liquids included in cavities in Cr are generally 
solutions of chlorides or sulphates. 

There is little doubt that these saline materials must form a 
very important constituent of the magma; but whether they play 
much part as a solvent medium for certain minerals is a thing yet 
to be experimentally verified, though one is inclined to think that 
they really do perform a very important function in that way. 


1 Annali del Reale Osserv. Meteor. Vesuviano, 1874, p. 73. 

2 Guarini, Palmieri, Scacchi. Mem. s. Incend. Vesuviano del mere di Maggio, 
1855, &e., pp. 141, 148, and 149. 

3G. F. Rodwell, Phil. Trans. Rk. S., Part iii., p. 1184. 


Lavis— On the Structure of Rocks. 155 


One point open to speculation is whether the presence of sodic and 
potassic chlorides and sulphates is not the determining cause as to 
whether the magma shall contain leucite haiiynite, nosite, or 
sodalite. or instance, we find Monte Vultura producing at 
different epochs basalts, leucitic basalts, and haiiynite basalts, 
which might result from the accidental introduction of such salts 
from the sea or other sources. We might suppose that the salts 
are decomposed and dispersed as acids, whilst the bases are seized 
upon by the silicic acid which, in a magma at high temperature, 
has powerful acid properties, and so forms minerals of the leucite 
or felspar groups. 

In this Paper I have brought together a considerable number 
of observations, and endeavoured to glean from them the clue to 
some of the most important problems of geological science. The 
train of argument is somewhat disorderly; but from the large 
number of circumstances that enter into the question of the forma- 
tion of igneous rocks, the subject is difficult of arrangement. it is 
unmistakably evident that if the young science of petrology is 
intended to be carried beyond the simple dry description of rock 
masses, it must be brought to bear upon the various modifications 
and derivatives of them, in any given district, and also that it will 
never supersede field investigation ; but by the two going hand-in- 
hand they may open the doors and show us the secrets of Nature’s 
great chemical laboratory—our globe. 


(se: ay 


XVIII.—ON THE PERMANENCY OF FROST-MARKS, AND A 
POSSIBLE CONNEXION THEREWITH WITH OLD- 
HAMIA RADIATA AND O. ANTIQUA. By J. JOLY, 
B.E., Assistant to the Professor of Engineering, Trinity 
College, Dublin. 


[ Read, March 24, 1886. ] 


Tue object of this note is more to draw attention to a line of 
inquiry, possibly not unfruitful, than, with the present amount of 
evidence, to demonstrate any hypotheses. ‘The experiments neces- 
sary to throw light on the hypothesis suggested demand more 
time than I will for many months be able to spare. Some few 
experiments have, indeed, been made, and, for more than a year 
seeking for leisure to continue them, I have postponed bringing 
the very simple matter before the Society. 

In the Christmas holidays of 1884, I, in company with some 
friends, was engaged on ashort excursion through the Co. Wicklow. 
The weather was frosty, freezing at night, and thawing by day in 
the sunshine. There had been rain, and the roads, where the thaw 
prevailed, were soft and muddy. In this mud, just outside 
Roundwood, we noticed very regular marks, evidently left by 
the frost. The frost was gone, and the mud was soft and wet; 
but in ruts and empty pools, wherever a smooth surface obtained, 
the frost had channelled its impress. The appearance was that of 
tufts, regularly radiating from a centre in rays which straggled 
over the slime in long tendrils, these being again often sub- 
divided into more numerous tendrils. The effect produced so 
closely resembled the tufted appearance of Oldhamia radiata, that 
the thought was immediately suggested of the possible common 
origin of the two, and I drew the attention of my companions to 
the resemblance, which one of them, Mr. Crosthwaite, was well able 
to appreciate, being familiar with the Oldhamia marks. 

Similar marks were subsequently met with in abundance that 
day, and again noticed in Glendassan the ensuing day. I have 
since observed them after every trost. 


Joty—On the Permanency of Frost-Marks. 157 


How the marks are caused, it is not hard to understand. Ifa 
surface consisting of loose small particles, holding water in the 
interstices, be exposed to a low temperature, certain of the more 
prominent particles, exposing a capillary surface of water more 
freely than their neighbours, become centres of crystallization, 
from which crystallogenesis is propagated, the molecular forces at 
work being sufficient to disturb the loose sand particles, so that 
they shall take up a position accommodating to the form and 
direction taken by the ice spicules. These spicules, or rays, 
would, if forming freely, extend, indeed, ever as straight lines; 
but here, hampered by the jamming or fixity of occasional par- 
ticles, they wander minutely, now diverted a little in one direction, 
and again in another, so that the sharp definition of crystalline 
shape becomes modified into a straggling growth, resembling the 
radiate straggling of Oldhamia radiata. 

There is another conspicuous variety of Oldhamia, known as 
Oldhamia antiqua. I traced, indeed, some marks remotely resembl- 
ing this; but, although we might a@ priori expect such a form to 
occur, I have not succeeded in finding anything fairly resembling 
it since, nor have I, in the few experiments made, succeeded in 
reproducing it. These experiments consisted in washing out the 
finer constituents of some earth, and exposing this, while saturated 
with water, to frost. I also froze a slab artificially, by placing 
immediately above it, in a well-padded box, a metal tray contain- 
ing a freezing mixture: freezing was produced by radiation from 
the surface of the mud to the bottom of the tray, which was 
coated with lamp-black. In this way, it was hoped, the conditions 
obtaining in nature would be preserved. In general, marks more 
or less resembling the Oldhamia radiata’ were easily obtained, but 
the Oldhamia antiqua could hardly be said to be reproduced. I 
said that we might expect a different result. This will appear if 
we consider the simple arrangement of such marking—a zigzag of 
nearly straight lines, with tufts at the bends or meeting-points. 
How such an arrangement might occur in the case of fine sand, 
interspersed with larger particles, is quite conceivable. Finally, 
anyone who has observed closely the symmetrical forms of frost 


! This is by far the more common variety. 
My 


158 Scientific Proceedings, Royal Dublin Society. 


on smooth surfaces will not think it improbable that on the sur- 
face of fine sand we should find it simulating organic form. 

My failure in obtaining the O. antiqua artificially may have 
been due to the texture of sand employed, to its degree of satura- 
tion, or, possibly, to the nature of the matter dissolved in the 
water. Thus, it might not be amiss to try experiments on the 
freezing of sea-water in mud or fine sand; and a sand made of 
the silurian slate itself, crushed to dust, commends itself, a 
as going towards realizing past conditions. 

The subsequent preservation of these marks in the mud during 
thawing and drying may be perfect, and conditions necessary for 
their continued preservation, as rock-marks are no harder to con- 
ceive than the conditions which have preserved to us the rain- 
marks so perfectly that we can pronounce, it is said, on the direc- 
tion of the wind prevailing during the shower. 

We have only to suppose alternations of high and low water— 
the silt-laden water creeping very quietly over mud flats which, 
frozen during exposure, were again thawed and dried before the 
incoming water deposited a fresh covering. 

It is noteworthy that the grosser spicules appearing on the 
surface of frozen mud leave, so far as I have observed, no impress. 
They are, in fact, formed merely in surface-water. 

It was hoped at first that evidence might be obtained from a 
comparison of the angles made by the bifurcating branches of 
the frost-marks with the angles easily measurable on the silurian 
slate. But as the crystallographic directions were found to be 
completely disguised in the first case, the comparison was futile. 

In bringing these observations to the notice of the Society, I 
hope it will be understood that I no more than venture a sugges- 
- tion, worthy, it is thought, of further elucidation, and not to be 
lightly dismissed. Even if, on further consideration, it be 
deemed improbable, it is perhaps not without interest, and, pos- 
sibly, not without important bearings in other directions to point 
out that the fragile and beautiful frost flowers, fleeting as they 
are, can leave an impress of a nature capable of being preserved 
through an eternity of time. 


| 169 J 


XIX.—NOTE ON LACKMOID AND LITMIN. By W. N. 
HARTLEY, F.R.S. 


[Read, March 24, 1886. | 


Last year Mr. H. N. Draper introduced to the notice of the Physi- 
eal Science Section of the Royal Dublin Society a new substance 
ealled lackmoid, which appeared to have the same, or very similar, 
properties to litmus. He kindly forwarded to me small specimens 
of lackmoid and litmin. The following notes show, first, that these 
are different substances; secondly, that they may be of a similar 
constitution; but we have no decided evidence. 

Lacknoid.—0:01 gram. was dissolved in 20 cubic centimetres of 
alcohol, of 0°8 sp. gr., and mixed with 20 cubic centimetres of 
water. The substance is soluble in strong alcohol, but insoluble 
in water. Soluble in alcohol of 50 per cent. by volume. It re- 
tained its colour with but slight alteration for several months, the 
sole change being the acquirement of a blue tinge. This may be 
due to the alkalinity of the glass of the bottle in which it has been 
preserved. 

Litmin.—0:01 gram. dissolved in 20 cubic centimetres of water 
and 20 cubic centimetres of alcohol, of 0°8 sp. gr. added. This 
substance is insoluble in strong alcohol, but soluble in alcohol of 
50 per cent., and in water. The solution has become bleached by 
keeping, notwithstanding that the bottle has been carefully stop- 
pered and not exposed to bright light. 

The spectra photographed for each solution after dilution were 
not remarkable ; the actinic absorption of the two substances being 
much the same, even after the addition of acid. Lackmoid has 
the more intense absorptive power in the visible spectrum; in 
solution it is undoubtedly a better reagent than litmus. The 
alcoholic solution may be added to water and used precisely as a 
litmus infusion. 


[Pe aLoOr 3) 


XX.—ON THE LIMITS TO THE VELOCITY OF MOTION OF 
THE WORKING PARTS OF ENGINES. By GEO. 
FRAS. FITZGERALD, F.T.C.D., F.B.S. 


[Read, March 24, 1886. ] 


Eneinets are used for transforming one kind of energy into 
another. 

Mechanical engines are of two great classes—ones that trans- 
form potential or statical energy into work, and those that trans- 
form kinetic energy into work. 

Slow-moving overshot waterwheels may be taken as types of 
the first class, and windmills as types of the second class. In all 
cases, it is of course possible by mechanical contrivances, such as 
levers, pulleys, wheels, &c., to obtain any velocity of moving 
parts; but the velocity I am calling attention to is the velocity 
of the parts that move with the working substance. Now, in the 
case of waterwheels it is evident that when the wheel turns so 
fast that the water in the buckets is descending as fast as it 
would fall freely, there can be no work being done by the water 
on the wheel, and so this limits the rate of working of the wheel. 
It is to be remarked that in the limiting case the efficiency is 
zero, while the power is zero when the efficiency is a maximum, 
i. e. when the wheel is turning most slowly, and that there is a 
rate of working intermediate between these for which the power 
is a maximum. In the case of windmills, when the sails turn so 
- fast that the wind blows on unstopped, there is similarly no work 
being done, and, just as in the other case, this limits their 
velocity. 

Heat engines are of a different class, as they are for the 
transformation of irregular into regular motion; but their 
mechanical, as distinct from their thermal, arrangements may be 
grouped as in the last case. Ordinary steam engines work by 
means of the energy in the steam doing work by pressing on a 
piston, and evidently this piston cannot move faster than the 
steam can follow it up. Professor Osborne Reynolds has in the 


Firzcrratp—On Limits to Velocity of Motion of Engines. 161 


March number of the Philosophical Magazine this year, called atten- 
tion to the way in which the velocity of flow of a gas into a vacuum 
is limited, and this limits the velocity of motion of the piston in 
an engine. He has, however, omitted to notice that there is a 
greater velocity than the velocity of sound with which a gas can 
move into a vacuum, namely, at the rate at which its particles 
are moving. ‘This only comes into effect when the space is so 
small compared with the free path that we cannot deal with the 
molecules, as making an indefinite number of encounters on their 
way across the vessel. In the case, for instance, of a piston in 
a vessel full of a gas moving suddenly from rest, with a velocity - 
equal to that of the average velocity of the molecules of the gas, 
which is greater than the velocity of sound in the gas, it is 
evident that all the molecules that were just on the point of 
striking the piston would follow it up, and that those that 
happened to be moving normally to it would keep following it 
up, and so would be diffusing into this vacuum, at a greater rate 
than the velocity of sound in the gas. This leads to a diffusion 
velocity of energy in a vacuum small compared with the free 
path, quite different from the velocity of sound, and upon which 
evidently radiometer action depend. It is this that would ulti- 
mately limit the rate at which the piston could be moved by the 
gas. I have explained this at my lectures on the Theory of 
Steam Engines for some years back. Steam may also be used 
kinetically, as in Giffard’s injector, and Hero’s engine; and in 
these cases velocity of motion is limited by the velocity of flow 
of the steam. : 
In the case of most of these engines that transform kinetic 
energy into work, it is to be remarked that when moving slowly 
there is a very small power produced at the expense of a great 
expenditure. For example, in Hero’s engine and engines of this 
type, if the steam runs out freely without moving the engine, 
there is certainly the maximum pressure tending to move the 
parts, but no power is produced, even though a great deal of 
steam is being employed. It is not the same with pressure 
engines, like ordinary steam engines. They may be worked 
slowly, and the power produced is proportional to the steam 
employed. The same distinction holds in the case of water 


engines working pistons and turbines. In the case of the kinetic 
SCIEN. PROC. R.D.S.—VOL. Y. PT. III. N 


162 Scientific Proceedings, Royal Dublin Society. 


engine we must work rapidly if we are to get a good efficiency, 
for the efficiency vanishes at the slow limiting velocity. In the 
case of statical engines, the efficiency is a maximum when they 
are working at their slow-limiting velocity, and vanishes when 
working at their quick-limiting velocity. In the case of a perfect 
turbine, the efficiency is a maximum when going at its quick- 
limiting velocity. In the case of water engines there is evidently 
a limiting velocity also depending on the rate of propagation of 
energy by the water, i.e. its rate of propagating sound. Gas 
engines have similarly a limiting rate of working, depending on 
the rate of explosion, i.e. of propagation of energy by the working 
substance. 

Capillary engines and muscles have probably limits of rates of 
working analogous to those depending on the rates of diffusion 
of the molecules of the working substances at the working sur- 
faces. We know that muscles like kinetic engines have a zero 
efficiency when working at their zero limit of velocity, and there 
is almost certainly a maximum limit to their rate of working. 
Capillary engines, like M. Lippmann’s, are evidently limited by the 
rate of diffusion of the molecules at the capillary surfaces, i.e. of 
the superficial energy. 

Electric engines have got analogous properties. There are the 
two classes—electro-static engines, such as a reversed Holtz 
machine, and electro-kinetic engines, such as ordinary magnetos 
and dynamos. ‘The former can be worked as slowly as we please, 
without waste of energy; but the latter require to be worked at 
near their limiting velocity to have a good efficiency. A limiting 
velocity in the case of dynamos is well known, and is attained 
when the inverse electro-motive force of the dynamo is equal to 
the driving electro-motive force; but with a given electro-motive 
force it does not seem at first sight as if there were any limit 
to the rate of working of a Holtz machine or any electro-static 
engine. 

If we, however, consider the electro-magnetic action of moving 
electricity, it becomes evident that the forces between the different 
parts of an electro-static engine must diminish ag its velocity of 
motion increases, until its parts have a relative motion equal to the 
velocity of light, when there will be no more forces between them. 
If it move faster than this it will become an electro-magnetic 


FirzcEraLp-—On Limits to Velocity of Motion of Engines. 168 


engine, for the electro-magnetic forces will become greater than the 
electro-static. ‘The way in which this acts is as follows :—Suppose 
a charged body, e.g. the carrier in any of the multiplier forms of 
electro-static engines, move near a conductor, it induces on this latter 
an electric charge which moves along with the moving carrier. I 
must neglect the resistance of the conductors, because it being of 
the nature of friction in ordinary engines limits the velocity in 
quite a different way from the ways I am considering. Now, if the 
carrier move with the velocity of light, it and its induced charges 
will have no action on one another, and so there will be no forces 
tending to move the carrier. Similarly, if a plate with a charge on 
it move parallel to a conducting-plate, the moving electrification 
while its velocity is increasing induces a current in the conducting- 
plate which is permanent, because the conducting-plate is supposed 
to be a perfect conductor, and the electro-magnetic action of these 
two, when the moving-plate moves with the velocity of light, is 
equal and opposite to their electro-static attraction. Thus it appears 
that the velocity of light isa limiting velocity to the rate of motion 
of these engines, just as the velocity of the particles of steam is a 
limit to the rate of motion of the piston ina steam engine. There 
is the same limit to the rate of working of electro-magnetic engines. 
Consider a very simple case. Suppose a wire sliding on two 
parallel rails with a magnetic force at right angles to their plane, 
and an electro-motive force driving a current round the circuit. 
If the magnetic force be feeble enough there seems at first 
sight no limit to the ultimate velocity of motion of the wire. If 
_ we consider, however, what takes place when the electricity goes 
across from the rails to the moving wire, we see that the reason it 
goes across is because an electrification on the rails induces a charge 
on the moving wire, and these attract one another and combine, this 
action being kept going constantly by the fresh charges supplied by 
the battery. Nowif the wire move with the velocity of light, there 
will be no longer any action between these charges, and so the wire 
will act practically as a non-conductor. A conductor moving with 
the velocity of light acts in other respects as a non-conductor, for it 
is evident that we can have any desired distribution of electricity 
in it or on it without any tendency for it to change. It would be 
more correct to describe it as a region in which the electro-static 
| inductive capacity was infinite, and where, consequently, ee 
| 
| 


q 


164 Scientifie Proceedings, Royal Dublin Society. 


charge produced no force in its neighbourhood. ‘There is another 
way of looking at this question, and one that leads to another view 
of the reason for this limiting velocity. It depends on the theory 
put forward by Professor Poynting that the energy given out at 
any point in an electric circuit is transferred there through the ether, 
and as energy is transferred through the ether with the velocity of 
light, it cannot keep up with a moving body that moves with a 
greater velocity than this. This completes the very remarkable 
analogy between the way in which the rate of motion of a piston 
by a gas is limited by the rate of propagation of energy in the gas, 
and the rate of motion of electric engines is limited by the rate of 
propagation of energy in the ether. 


ettoon a 


XXI.—ON THE OCCURRENCE OF HARMOTOME AT GLEN- 
DALOUGH, CO. WICKLOW. By J. JOLY, B.E., Assistant to 
the Professor of Civil Engineering, Trinity College, Dublin. 


(Read, April 21, 1886.] 


As I can find no previous mention of the occurrence of harmotome, 
or indeed of any member of the zeolite family of minerals, in Co. 
Wicklow, it may not be amiss to call attention to its presence. I 
have the more excuse for writing a note on the occurrence of this 
one mineral, as, since the work of Daubré, a special geological and 
mineralogical interest is attached to the beautiful group of which 
it is a member.! 

The harmotome of Glendalough occurs in the out-put from the 
Luganure lode, which traverses the granite close to its junction 
with the schist, and extends into the vale of Glendasan. Much of 
the gangue has been thrown out at the upper end of the lake, and 
from this debris I took, some few years ago, a very small specimen 
of the zeolite—so small that I could not be assured of its identity 
as harmotome till I was so fortunate recently as to find another 
and larger specimen. The out-put otherwise indicates hydro-ther- 
mal action in the lamellar deposits of quartz and calcite. Here 
also may be found fluorite, sphalerite, barite, strontianite, galenite, 
pyrite, siderite, chalcopyrite, manganocalcite, and some decompo- 
sition products. Specimens of hexagonal calcite, sometimes found 
here implanted in solitary whiteness on ice-like drusy quartz, 
are very beautiful. 

The zeolite, in both the specimens found, occurs implanted on 
a quartz matrix, and in one case the little crystals curved over a 
crystal of sphalerite. The largest of these harmotome crystals is 
not quite one centimetre in length. They present principally a 


1 Formation Contemporaine des Zedélithes. The zeolites observed by Daubré were 
engendered in the matrix rather than deposited. I think it evident that the Glenda- 
lough zeolite was deposited. Daubré’s harmotome or christianite, however, is the lime- 
potash zeolite philipsite of Dana, and is quite distinct from the harmotome Gescrie! 
above, which is the barium zeolite, 


166 Scientific Proceedings, Royal Dublin Society. 


characteristic cruciform twinning ; but a more obscure lamellar 
form, of the same mineral probably, is intermingled with the 
larger crystals. These larger crystals have a high vitreous lustre, 
and are white, translucent, transparent. The lamellar forms are 
duller in lustre and are white, nearly opaque. 

Crystallographic character.—The accompanying figure, in iso- 


metric projection, shows the nature of their crystallographic appear- 
ance. It differs somewhat from that ascribed to harmotome by 
Dana, Des Cloizeaux, &c., due to the conspicuous development of the 
hemihedral form 1 (copying the notation of Dana), while still pre- 
serving the holohedrism of the prism I. It will be seen that this 
development has reduced one set of the prism faces to minute 
dimensions. Indeed they can hardly be seen on the specimen 
without the use of a lens. Im any other specimens I have 
examined the prism is either predominant—1 having the appearance 
of a mere bevelling of the edge OI, or otherwise, it is eliminated 
altogether, I becoming a hemihedral form. The effect is that the 


JoLy—On the Occurrence of Harmotome at Glendalough. 167 


crystal looks as if terminated with four smooth planes, and only on 
very close examination is it apparent that the pyramid is trun- 
cated and replaced by the four prismatic faces. Many of the 
erystals are terminated thus at both ends. 

Working with a defective goniometer, the following values were 
obtained :— 


Onvnl=90°; 
Ip os 1s 20’, mean of nine observations ; 
Ta I = 110° 20’, mean of four observations. 
Dana records harmotome as orthorhombic, and 
| Tal =124°47’; 
LT = Le ae, 


Thus the measurements are evidently sufficiently in accord with a 
right rhombic prism of 124° 47’. Further, the angle I I agrees 
satisfactorily with the recorded value. Observations with the 
polariscope confirms the crystallographic characters ascribed to 
these faces, but, owing to the generally imperfect translucency of 
the crystals, are not very definite. 

Specific gravity.—I mentioned opaque, white, lamellar forms. 
To these optical or crystallographic investigation could not be ex- 
tended. Thinking they might be a distinct zeolite, it was thought 
advisable to compare their sp. gr. with that of the other implanted 
crystals. Otherwise, also, it was evidently advisable to determine 
the sp. gr. of both forms. 

In a diffusion zone above Thulet’s solution, according to Pro- 
fessor Sollas’ method, a fragment of authentic harmotome was 
placed. On putting in, now, fragments of both the Glendalough 
forms, they were found to float exactly in the same horizon with 
the authentic harmotome. Orthoclase of a sp. gr. 2°51 floated 
below them, analcite floated much above them, stilbite higher still. 
By calculation, then, asp. gr. of 2°46 (Dana 2:44-2:45) was ascribed 
to the Glendalough harmotome. This is a very distinctive test, as 
the only other members of the zeolite family with so high a sp. gr. 
are the monoclinic varieties, scolocite and brewsterite. 


168 Scientific Proceedings, Royal Dublin Society. 


Fusibility—Compared with authentic harmotome on the mel- 
dometer it was found that the fusion of both occurred simultane- 
ously at a very high temperature. ‘The specimens also blanched 
below a red heat. It was interesting to compare this behaviour 
with that of some other zeolites. The result is the following order 
of fusibility with increase of temperature :— 


Chabasite 

Stilbite almost simultaneously. 
Heulandite J 

Natrolite 

(Orthoclase) 

Harmotome. 


Harmotome is, in fact, separated from the others by a wide 
interval. Orthoclase fuses in this interval, and, indeed, decomposi- 
tion or ebullition of the orthoclase takes place before the melting- 
point of harmotome is reached. Recent experiments gave me for 
the melting-point of orthoclase the temperature of 865° C. It is 
likely that the fusion of harmotome does not occur under 900° C. 
T had not time to go through with the measurement independently. 
I would point out, however, that there is very little liability to 
error in comparing the fusibilities of two substances, placed thus 
under exactly the same conditions and observed simultaneously in 
the field of the microscope. On the other hand, not only is the 
blowpipe a powerful chemical agent, and thus obscures the pheno- 
mena of fusion with secondary effects, but with it it is impossible to 
be sure of fair comparison. ‘The meldometer has shown me that 
the order of Van Kobel’s scale is incorrect. Thus the order it 
assumes for the fusibilities, almandine, green actinolite, orthoclase, 
should be orthoclase, green actinolite, almandine ; and it is, I think, 
allowable to assume that similar misleading phenomena account for 
the fusibility of harmotome being recorded as 3°5 on the scale of 
Van Kobel. The test of fusibility, like that of sp. gr., is thus a 
distinctive one in the case of harmotome. 

A test of its hardness showed that it scratches fluorite, and is 
scratched by apatite; hardness, therefore, 4:5. In the dlowpipe it 
fuses without intumescence. 

It does not gelatinize with, but is decomposed by, hydrochloric 
acid. ‘These tests confirm its identity with harmotome. 


[ehoons] 


XXII.—-ON THE TEMPERATURE AT VARIOUS DEPTHS IN 
LOUGH DERG AFTER SUNNY WEATHER. By GEO. F. 
FITZGERALD, F.T.C.D., F.R.S. 


Read, April 21, 1886. 
p 


Tue measurements upon which this Paper is founded were made by 
me in the month of July, 1876, and I would have hardly thought 
them worth recording only that I have lately seen it noticed as a 
new fact that the isothermal surfaces in the Lake of Geneva are 
not level surfaces; and that this was so in Lough Derg was one of 
the special features I remarked in my observations of nearly ten 
years ago. 

I made experiments with a maximum and minimum thermo- 
meter, attached to a sounding-line, and the differences of tempera- 
ture observed were so great that there could be no doubt, even 
with rough experiments. 

The observations were made after a long continuance of hot, 
sunny weather, during which the day temperatures ranged from 
73° FB. to 75° F., and the night temperatures from 55° F. to 65° F. 

The temperature of the surface of the lake rose rapidly during 
sunshine, at a rate of nearly a degree per hour. In the deep 
water the temperature of the surface did not rise so fast as in the 
shallow water. About 3:30 in the day the temperature of the 
surface water in the deep parts was 71° F., and in the shallows 
75° KF. From a calculation of the amount of heat that enters the 
water, it seems that only about =5th, or less, was used in heating 
it, the rest being probably spent in evaporation. During the 
evening the temperature of the surface fell slowly, until in the 
morning it was uniform, to a depth of about five yards, this being 
the depth, apparently, that the convexion currents during the 
night reached. This temperature was, on the night I observed 
it, eleven degrees above the night temperature of a thermometer 
exposed on grass. In the shallow water the temperature fell more 
rapidly until it was about 2° colder than the surface water in deep 
parts, and nearly the same as that of the water at the bottom of 


170 Scientific Proceedings, Royal Dublin Society. 


the deep parts of the lake. It thus appears that the cold water 
supply for the bottom of the lake may be kept up by the cold 
night water from the shallows. 

On laying out a series of afternoon isothermal lines, it appears 
that they are closer together in the shallow water than in the deep 
water, the bottom in the shallower water being in general colder 
than at the same depth in deep water, though, of course, in the 
very shallow water, where the surface was several degrees hotter 
than elsewhere, the whole of this very shallow water was warmed 
up, and was hotter than water at the same level elsewhere. The 
rate of change of temperature downwards was very regular, from 
a depth of from five to six yards, to the bottom. At the depth of 
five to six yards, it changed more rapidly, and from that up to the 
surface was the region that was affected by the diurnal changes of 
temperature. During the day the upper layers in this region 
became much hotter, and during the night the whole of this 
region gradually became of the same temperature throughout. 
The depth of this region was observable, during the days I 
observed it, by the variation in the rate of change of temperature 
that occurred at this depth; the change of temperature was more 
rapid here than in either the subjacent or in the immediately 
superincumbent layers. 

From the rate of decrease of temperature in the superficial 
layers I calculated that the coefficient of absorption of heat per 
yard was ‘71, but as it is known that this is very different, for 
different rays of the spectrum, it is probable that the coefficient of 
absorption of the first layers is very much greater. I had not any 
sufficiently accurate method of measuring the temperatures at near 
points to determine the rate of change of temperatures for small 
distances near the surface, but it was certainly very much more 
rapid than even at a short distance below the surface. 


XXIII.—A THERMO-ELECTRIC CURRENT IN SINGLE CON- 
DUCTORS. By FRED. T. TROUTON, B.A. 


[ Read, March 24, 1886.] 


Ir a flame be placed under an iron wire in circuit with a galvano- 
meter, and be so moved along the wire that the part in the flame is 
always white-hot, a current is indicated which flows in the direction 
the flame is carried. The electromotive force is generally in the 
fourth decimal place. In looking for an explanation of this, it 
was observed that in front of the flame the fall in the temperature 
along the wire is more rapid or steeper than behind it. So that, if 
a difference in the rate of transference of heat in opposite direc- 
tions in a wire causes a current, as some have supposed, there would 
be one in this case. The rate of flow of heat is greatest in the 
direction the flame is moved, for the fall in temperature along the 
Wire is most rapid in that direction. The current, then, and the 
greatest flow of heat are in the same direction. The amount of the 
current would thus obviously depend on the difference of the gra- 
dients in temperature in either direction along the wire. By making 
the gradient in front as steep as possible, and that behind the flame 
more gradual, we should expect an increase in the current. Or 
again, by making the gradient behind the flame steeper, by cooling 
it more rapidly,than the air can, say by applying water, we should 
get a decrease in the current, and even a reversal if the gradient 
became steeper than in front. It was with no small surprise, then, 
that the opposite was observed on trying the experiment. For, 
cooling with water behind the flame as it moved along was found 
to increase the current. That this could not be due to chemical 
action was ascertained by applying various substances to cool the 
wire. Thus, whether bodies of a reducing or oxydizing nature 
were employed the result was always the same. 


172 Scientific Proceedings, Royal Dublin Soctety. 


In order to simplify matters by observing the current when 
only one side of the flame changed, a row of burners were so 
arranged that one after the other could be lighted beneath the 
wire. The current, on turning on the burners in succession, was in 
the direction that the ignition travelled, or to the side of the steepest 
gradient in temperature. On turning the burners out in reverse 
order, one after the other, the current now flowed in the opposite 
direction to that indicated in the first instance. And if was in- 
ereased when the cooling was hastened by applying water. ‘The 
steep gradient is, in both cases, on the same side; that is, both 
while the flame is spreading out, and again while it is going back. 
Yet the currents are in opposite directions. However, though the 
steep gradients are on the same side, it is to be remarked that 
everything is not in the same condition in both cases; for in one 
the temperature is everywhere rising, while in the other, that is as 
the flame goes back, the temperature is everywhere falling. So 


that it ela be insufficient to consider the electromotive force 


/ 
B= (F \ but must rather be « = @ (o> up 6 being the tempera- 


dx b) 
ture at se point at a distance w along the wire from a fixed point, 
and ¢ denoting the time. 

Direct experiments were made to determine if a difference in 
the flow of heat in opposite directions in a wire was sufficient alone 
to produce a current. ‘Thus, along a wire on one side of a heated 
place a moist thread was laid and kept moistened. On coming to 
a permanent state no appreciable current was observed, though 
there must be a very great difference in the rate of flow of heat to 
either side, due to the great difference in the temperature gradients. 
I find a similar experiment was made by Le Roux,' who came also 
to the conclusion that no current whatever was produced by a dif- 
ference in the flow of heat in opposite directions in a wire. In 
another experiment no current was observed in a wire kept heated 
at the place where it came up out of a vessel of water. So that 


: dd dd 
there can be no term in «= @ a aa =| containing at ;, alone ; but 


ad’ 


it probably consists principally of = dt. 


1 Annales de Chemie et de Physique, quatriéme séries, tome x., p. 208. 


Trovron—On Thermo-Electric Current in Single Conductors. 173 


We may picture what occurs when the high temperature spreads 
out along the wire somewhat as follows:—When the temperature 
of a portion is raised to a bright heat, let us suppose the structure 
to be altered, and with it the electrical potential. Let mn represent 
the wire, and the ordinates of the curve the temperature at each 
point. Then, for simplicity, let us for the moment suppose that the 
difference from the altered part to the unaltered is sudden in the 


Ai ion we encore ba 


AB BA Me 


wire and not gradual. Say, at 4B and again at BA, so that from 
A to B there is a difference in the potential, and again of the same 
amount, but in the opposite sense at AB. Now, if the temperature 
spread out on one side, as represented by the dotted line, the junc- 
tion BA will go out to BA’. However, if we suppose the high 
temperature to travel out faster than the junction, while the junc- 
tion.is behind its final position, itis at a higher temperature than the 
junction at AB; and there will be a current, flowing from m to x, 
if the potential of the centre part was originally higher than the 
rest of the wire. The reverse occurs when the high temperature 
goes back. The junction follows slower and is at a lower tempe- 
rature than AB until it arrives at the final position. The fall in 
the potential is meanwhile less than at AB. So the current in this 
case flows from x tom. Now, if we suppose a great number of these 
junctions beginning with the unaltered wire, and ending with the 
completely altered, each will have its own normal temperature and 
can act justas described above in the case of one. By supposing a 
sufficient number of these we have at length a continuous alteration 
in the structure of the wire, which is what probably takes place. 


peti. Bas 2) ee 


SSS 


In the case of the moving flame the junction in front is at a 
higher, and the one behind at a lower temperature, than the tem- 


174 Scientific Proceedings, Royal Dublin Society. 


perature when at rest, which is shown on either side in the figure 
by the dotted lines of equal length. The arrow shows the direc- 
tion the flame is moving. 

If water be applied to one side of a heated part of the wire, 
there is a very rapid cooling and a current flows, due to the higher 
temperature on the other side, until the junction slowly travels 
in to the point at the normal temperature, when the current ceases, 
as was described above.t Again, on stopping the water, the current 
flows for a while in the opposite direction. 

So far it has been assumed that the iron, as the flame moves on, 
cools and returns to its original state; but it does not do so com- 
pletely. However, if the flame be passed several times over the 
same part, the iron seems after that to undergo no further altera- 
tion. There is a permanent heterogeneousness or alteration found 
from the place where the heating by the flame began to where it 
ended, similar to that between the wire and another metal. Hither 
of the ends of this gives a current on heating. In some cases, 
especially in steel, the currents were easily observed, even at 100° C. 
The current, as in the case of the temporary alteration in the wire, 
flows from the altered to the unaltered metal at the hot junction. 
It follows from this, that the first time the flame is moved along 
the wire the current is somewhat greater than subsequently, 
it being the sum of both effects; though afterwards it appears not 
to alter sensibly in amount on repeated heatings. ‘That currents 
due to permanent alteration in the structure of metals could be 
obtained, was long ago shown by Magnus. 

Of other metals examined, nickel acts like iron; copper, silver, 
and platinum appear not to—that is, an alteration once made in 
their structure remains on cooling; while iron and nickel return 
partly to their original state. This difference may be owing to 
the more or less pasty condition iron and nickel assume at tempe- 
ratures considerably below their melting points; and, probably, 
both copper and silver raised to temperatures just beneath their 
melting points would behave like iron or nickel. The difficulty of 


" That Le Roux did not observe these currents may be due to his not employing as 
high a temperature. 


Trouron—On Thermo-Electric Current in Single Conductors. 175 


doing this is considerable, especially in silver, for long below its 
melting-point it appears to lose tenacity almost completely. 
Platinum was examined at temperatures approaching its melting 
point with the oxyhydrogen flame; but the currents obtained were 
very small, and were due to irregularities in the structure of the 
wire. As the flame was being carried along in one direction the 
needle kept to one side or the other, according to the part of the 
wire the flame was at. A thin rod of carbon examined in the oxi- 
hydrogen flame gave a small but regular current as the flame was 
moved along when water was applied to cool the carbon behind the 
flame ; without this the carbon does not cool quickly enough to give 
a current. 


A difference in the potential along a wire of the nature sup- 
posed above, that is due to a temporary change in structure from 
temperature, could not be discovered by means of a galvanometer, 
owing to the symmetry on either side, except the temperature 
alter more rapidly than the structure. For otherwise it would 
always be equivalent to introducing another metal, and keeping 
the two junctions at the same temperature. 


To state shortly the conclusions finally arrived at, there is, 
first, a permanent alteration effected in the structure of a wire 
when it has been once heated. So that, if one of the points 
between the altered and unaltered metal be warmer than the 
other, a current flows similar to what would happen if a second 
metal were introduced into the circuit instead of the altered part. 
Secondly, that there is, at least in some metals, a temporary 
alteration of a somewhat similar nature to the permanent one, 
which lasts while the wire is at a high temperature; and that it is 
possible to obtain currents from this, is solely due to the fact that, 
both in appearing and in disappearing, the alteration may take 
place more slowly than a change in temperature, which ultimately 
effects the alteration. 

What this alteration is, whether stresses similar to what Sir 
William Thomson found could produce thermo-electric hete- 
rogeneousness in a single metal, or whether of the nature of 
molecular rearrangement of the nature of annealing, may be 
doubtful. 


176 Scientific Proceedings, Royal Dublin Society. 


A better knowledge of the circumstances under which currents 
can be obtained in one metal may, perhaps, yet afford ground for 
some molecular theory of thermo-electric currents, the con- 
ditions to be considered being reduced in having only one sub- 
stance in different states to deal with. 


elvan 


XXTIV.—PRELIMINARY ACCOUNT OF THE TETRACTINELLID 
SPONGES DREDGED BY H.M.8. CHALLENGER, 
1872-76. By PROFESSOR W. J. SOLLAS, LL.D., 
D.Sc. Part 1.—Tur Cuortsripa. 


[Presented, July 15, 1886.] 


Tue following short abstract of my forthcoming Report on the 
Challenger Tetractinellid Sponges is published by kind permis- 
sion of Dr. John Murray, Director of the Challenger Expedition 
Reports :— 


Trise I.—TETRACTINELLIDA, Marshall. 


Skeleton characterized by quadri-radiate spicules, or “ Lithistid”’ 
sclerites. 

Order I. Cuortstrpa, Sollas.—Quadri-radiate spicules are 
present, but not “ Lithistid”  sclerites. 

Order II. Liruistripa, Zittel.—The chief skeleton consists of 
“Vithistid” sclerites articulated to form a consistent network. 
Quadri-radiate spicules may be present or not. 


Order 1. CuHoristTIpa. 


Sub-order 1. Tsrrapina.—The chief spicules of the choano- 
some are tetrads, amphitetrads, candelabra, or modified triana. 

Sub-order 2. Trrantna.—The heads of the adult trianine 
spicules are confined to the ectosome. 


Sub-order 1. TErTRApDINA. 


Family 1. PLAKINIDA.—The canal system is eurypylous. 
Candelabra are present. 

Family 2. PACHASTRELLIDZ.—The canal system is either 
eurypylous or aphodal. The tetrads are simple. 

Family 3. CORTICIDA.—The canal system is aphodal ; ths 
characteristic tetrads are candelabra, or forks with trifurcate arms, 


or forks with the surface ornamented by spines, or amphitetrads. 
SCIEN. PROC. R.D.S.—VOL. V. PT. 1V- O 


178 Scientific Proceedings, Royal Dublin Society. 


Sub-order 2. TRIANINA. 


Family 1. TETILLIDA.—Flesh spicules are arculi or spirule ; 
the triana are characteristic; the canal system in the lowest 
forms is eurypylous, in the highest, aphodal; the ectosome in the 
lower forms is the outer epithelium and a thin layer of collenchyme ; 
in the higher, a highly differentiated cortex ; choanosome, a collen- 
chymatous mesoderm in the lower forms, sarcenchymatous in the 
higher. 

Family 2. THENEIDA.—The flesh spicule is a spini-spirula ; 
stellates are absent; the canal system is eurypylous; the ectosome 
is not differentiated to form a cortex; the mesoderm is collen- 
chymatous. 

Family 3. STELLETTIDA.—The characteristic flesh spicule is 
a stellate; other forms may also be present; the canal system is 
aphodal, but approaches the eurypylous type in the lower forms; 
the ectosome may, or may not, form a cortex; the mesoderm of the 
choanosome a sarcenchyme. 

Family 4. GEODINID#.—The characteristic spicule is the 

globate; the canal system always aphodal; the cortex always well - 
differentiated ; the mesoderm of the choanosome a sarcenchyme. — 


Sub-order 1. 
Family 1. PLAKINIDZ, Schultze. 


Genus 1. Epailax, g.n.—Plakinide, with large acerate spicules 
and small quadriradiate spicules. 

Epallaz callocyathus, sp. n.—Sponge, vasiform, expanding 
towards the upper margin, which is rounded, and gently undulat- 
ing, produced into a short, strong slender stalk below, by which 
it is attached; walls thin; oscules small, opening into the interior 
of the cup in longitudinal linear series irregularly alternating ; 
pores, in sieves on the outer surface, overlying the incurrent canals, 
which interdigitate with the excurrent canals, both being wide- 
branching sinuses produced by a folding of the choanosome. Both 
surfaces hispid; ectosome thin, collenchymatous ; choanosome, a 
collenchymatous mesoderm; eurypylous flagellated chambers. 
Spicules—(1) acerate, 3:04 by 0°078 mm.; (2) acerate, 3:93 by 


\ 


Sortas—On Tetractinellid Sponges. — 179 


0:039 mm.; (3) calthrops, usually quadriradiate, but frequently 
tri- and bi-radiate, or sometimes quinqui- and sex-radiate; one 
ray of a tetrad, 0°0276 by 0:004 mm.; (4) stellates: these differ 
from the calthrops by possessing more numerous and smaller rays. 
Habitat.—Station 192, lat. 5° 49’ 15” 8.; 182° 14’ 15” E.; 
140 fms. 
Family 3. CORTICIDA. 


Genus 1. Thrombus, g.n.—Corticidz, containing spined forks 
like those of Corticium kittoni, Carter (Thrombus kittont), see Ann. 
Mag. Nat. Hist., ser. 4, vol. xiv., p. 24. 1874. 

Thrombus challengeri, sp. n. Ee Mcodena: a collenchyme which 
contains numerous oval granular cells, 0°016 to 0:02 mm. in 
diameter. Spicules like those of Thrombus kittoni, but larger ; 
fork, shaft, 0'1 by 0°012 mm.; arms, 0°055 by 0:012 mm. 

Habitat.—Station 177; lat. 16° 45’ 8.; long. 168° 7’ W.; off 
Api, New Hebrides, 130 fms. 


Sub-order 2. 
Family 1. TETILLIDA. 


Genus 1. Tetilla, O. Schmidt.—The ectosome never forms a 
cortex, and is not provided with special spicules; the mesoden 
is a collenchyme, and the canal system eurypylous. ‘ 

Tetilla sandalina, sp. u.—Sponge small; more or less ellipsoidal, 
or fusiform ; a single lateral oscule at one il ectosome not deve- 
loped ; flagellated chambers large. Spicules—(1) fusiform acerate, 
2°326 by 0:0237 mm.; (2) trichite acerates, 0°395 mm. long ; 
immeasurably thin; (8) trifid forks with filiform proximal ends ;, 
arms of unequal length ; one about 0:197, the other two 0-0513 mm. 
long; (4) arculi and sigmelle about 0025 mm. long; anchors 
absent. 

Habitat.—Azores, lat. 87° 26’ N.; long. 55° 13’ W. 1000 ome 


Tetilla leptoderma, sp. n.—Sponge small; somewhat spherical ; 

a single oscule, lower surface produced into slender rootlets, 

ectosome thin ; flagellated chambers large. Spicules—(1) a fusi- 

form acerate, 4:185 by 0:0474 mm.; (2) trifid forks, filiform at 

one end, rays of unequal length at the other, 4:03 by 0:0118 mm. ; 
202 


180 Scientifie Proceedings, Royal Dublin Society. 


the longer ray is 0°197, the two shorter, 0°106 mm. long ; 
(3) trichite forks, similar to the preceding, but smaller, and of 
hair-like fineness; shaft, 1:162 mm. long; (3) somal anchor, a 
fusiform shaft, with a filiform end, 6:0 by 0:01 mm.; arms, 0°118 
by 0:012 mm; (4) radical anchors similar, but with a more mas- 
sive head, and a distal mucrone; shaft, 6°8 by 0:0276 mm.; arms, 
0:154 by 0:0237 mm.; (5) arculi and sigmelle about 0:0125 to 
0:019 mm. long. 
Habitat.—Lat. 37° 17’ S.; long. 538° 52’ W. 600 fms. 


Tetilla grandis, sp. n.—Sponge large, massive, sub-cylindrical, 
or sub-ellipsoidal, seated on a massive base of tangled anchoring 
spicules; oscules numerous, simple; surface hispid; ectosome, a 
fibro-vesicular collenchyme. Spicules—(1) fusiform acerate, 6:07 
by 0:075 mm.; (2) trifid fork ; shaft cylindrical; a filiform end ; 
8°67 by 0:016 mm., to 11°8 by 0:082 mm.; rays, 0°15 by 0:0118 
tm. ; (3) trichite fork, with one ray longer than the other two ; 
(4) somal anchor, a fusiform shaft with filiform end, 12:14 by 
0:02 mm.; rays, 0°16 by 0:012 mm. ; spread, 0:16 mm. ; (8) radical 
anchors, similar, but with a thicker head and shorter, stouter rays ; 
shaft, 31°50 by 0°315 mm.; rays, 0-1 by 0°024 mm.; spread, 
0:1 mm.; (6) arculi and sigmelle, 00118 mm. long. In small 
specimens the spicules are smaller; thus, in one 18 by 13 mm. in 
diameter, the acerate is only 30 mm. long, in another, 32 by 
26 mm., it is 4°65 mm. long. 

Habitat.— Kerguelen and Christmas Island. 10-150 fms. 


Tetilla pedifera, sp.n.—Sponge small, somewhat thumb-shaped ; 
surface hispid ; oscules numerous, small ; ectosome thin, supported 
by numerous acerates lying parallel to its surface. Spicules— 
(1) fusiform acerate, 3:2 by 0:03 mm.; (2) forks, a slender shaft, 
with a filiform end; arms of unequal length, varying from 3 to 1 in 
number ; shaft, 2°38 by 0:012 mm.; arms, long ray, 0°15 mm. ; 
two short rays, 0:06 mm. long; (3) anchors; arms reduced to one, 
so that the spicule somewhat resembles a shepherd’s crook ; shaft, 
4°46 by 0:0276 mm.; ray. 0:13 mm. long; spread, 0°055 mm. 

Habitat.—Lat. 0° 48’ 30” 8. ; long. 126° 58’ 80” H. 826 fms. 


Genus 2. Chrotella, g. n.—The ectosome is a fibro-vesicular 


Sottas—On Tetractinellid Sponges. 181 


collenchyme, with acerate spicules strewn through it in various 
directions, but not at right angles to the surface ; the mesoderm is 
a granular collenchyme; the canal system eurypylous, or aphodal. 

Chrotella simplex, sp.n. Sponge somewhat spherical; surface 
pilose ; oscules, one or more, minute. Spicules—(1) fusiform 
- acerate, 3:0 by 0:0237 mm. ; (2) trifid fork; shaft, with a filiform 
end, 3-4 by 0:02 mm.; rays, 0°158 by 0-016 mm.; (8) anchor; 
shaft, with a filiform end; axial fibre produced distally beyond 
the origin of the rays; shaft, 5°35 by 0:016 mm.; (4) sigmella 
and arculus, 0:0118 mm. long. 

Habitat.—Lat. 16° 50’ N.; 25° 8’ W. 260 fms. 


Chrotella macellata, sp.n.—Sponge spherical, depressed, with a flat 
base ; oscules multiple, each leading into a large cloacal chamber ; 
surface, hispid ; flagellated chambers small. Spicules—(1) fusiform 
acerate, 5°7 by 0:055 mm.; trifid forks, with short prongs, highly 
porrectate, 0:08 by 0:02 mm. ; shaft, fusiform, 7-95 by 0:0276 mm. ; 
(3) trifid fork, with longer rays, less porrectate, 0°23 by 0:02 mm. ; 
shaft, 2°5 by 0:24 mm. ; (5) two-pronged (dicellate), and one- 
pronged (macellate) forks, derived from No. 4 by reduction in the 
number of the rays; shaft, 3°49 by 0:0316 mm. ; prongs of dicel- 
late form, 0°44 by 0:0316 mm. ; of macellate, 0°58 by 0:0316 mm. ; 
(6) anchors, shaft, 6°5 by 0:°016 mm.; rays, 0:06 by 0:014 mm. ; 
(7) arculi and sigmelle from 0:012 to 0°016 mm. long; (8) a sig- 
mella with two turns (= a spirula), characterizes the cortex, 0:03 
to 0:04 mm. long. 

Habitat.—Lat. 11° 37’ N.; long. 123° 31’ H. 18 fms. 


Genus 3. Craniella, O. Schmidt.—The cortex is differentiated 
into an inner fibrous, and outer collenchymatous layer; the latter 
excavated by intercortical cavities; the former traversed at nght 
angles by cortical acerates; the mesoderm of the choanosome is 
a sarcenchyme ; the canal system is aphodal. 

Craniella bowerbankii, sp .—-The spicules include—(1 fusiform 
acerates of the body, 3:26 by 0:047 mm., and of the cortex 1-4 by 
0:04 mm. ; (2) forks, with a shaft, 5-12 by 0°024 mm.; rays, 0°12 
mm. long.; spread, 0:06 to 0:07 mm.; (8) anchor, 5°8 by about 
0°02 mm. The axial fibre of the shaft is continued into the head 
past the origin of the arms. Arculi andjsigmelle absent. 


182 Scientific Proceedings, Royal Dublin Society. 


Habitat.—Port Jackson, var a.; Sydney, 35 fms., var. 6.; Zam 
boanga, var. c.; lat. 10° 80’S.; long. 142° 18’ H.; 8 fms. This is 
probably one of the two very different sponges which were named 
T. simillina by Bowerbank. 


Craniella pulchra, sp. n.—Spicules—(1) fusiform acerate 4:6 by 
005 mm. Small acerate of the cortex 1:2 by 0:0395 mm. ; 
(2) trifid fork, shaft 7-1 by 0:°0225 mm.; prongs 0.125 mm. long. ; 
(3) anchor, shaft, 8°57 by 0:0165 mm. ; rays, 0:0484 by 0:012 mm. ; 
the axial fibre of the shaft extends into the head beyond the origin 
of the rays. 

Habitat.—Lat. 16° 50’ N.; long. 25° 8’ W. 260 fms. 


- Craniella carteri, sp. u.—Cortex, distinguished by curious cell- 
ageregates, distributed through its outer collenchymatous layer. 
These parenchyma-like masses of cells are sharply distinguished 
from the surrounding tissue, they scarcely stain with reagents, 
and contain ochreous-coloured spherical granules. Spicules— 
(1) fusiform acerate, 2°6 by 0:035 mm., and a smaller acerate of 
the cortex; (2) trifid forks, shaft, 3:5 by 0:014 to 0-016 mm.; 
rays, 0°0868 by 0°012 mm.; (4) anchors, with rays not quite 
terminal, the shaft being continued far enough to give a double 
curvature to the distal margin: shaft, 6°75 by 0°02 mm.; rays, 
0°06 mm. long. Arculi and sigmelle absent. 

_ Habitat.—Bahia. 


Craniella schmidti, sp. n.—Spicules—(1) fusiform acerate, 1:34 
to 2°23 by 0:03 mm.; and smaller acerates of the cortex, 0°414 
by 0:0276 mm. long; (2) trifid fork, two varieties which pass into 
each other ; one with short, stout, rays, 0°127 by 0:0237 mm.; the 
other, with longer, slenderer, rays, 0°142 by 0:012; (8) anchors, 
rays, 0°075 by 0:016 mm.; spread, 0°01 mm.; the axial fibre 
extends into the head; (4) arculi and sigmelle, 0°0197 mm. long. 

Habitat.—Lat. 38° 30’ N.; long 31° 14 W.; 1000ims. ‘This 
sponge is probably one of those which O. Schmidt has named 
Sraniella cranium, which is a purely northern species, and it appears 
doubtful whether Schmidt had ever seen it. 


Genus 4. Cinochyra, g.n.—The ectosome forms a cortex, 
which consists chiefly of a dense fibrous felt; cortical acerates 


Sottas—On Tetractinellid Sponges. 183 


traverse it transversely ; the innermost layer of the cortex is free 
from spicules ; the cortex is not excavated by intercortical cavities ;' 
the oscules and pores are confined to special flasked-shaped recesses ; 
the mouth of each flask is sphinctrate; the walls are perforated by 
pores which communicate with the incurrent or excurrent canals, 
as the case may be; the mesoderm of the choanosome is a granular 
collenchyme; the canal system is eurypylous. 

Cinochyra barbata, sp. n.—Sponge sub-spherical or sub-cylin- 
drical, seated on a dense mass of its own anchoring filaments. 
Oscules and pores as in genus. Spicules—(1) fusiform acerate, 
8:03 by 0°71 mm.; and a smaller acerate of the cortex, 0°892 by 
00355 mm. ; (2) forks, a fusiform shaft, 13°21 by 0:0296 mm.; 
rays, 0:178 mm. long; (8) trichite forks, shaft, 0:13 by 0-004 mm. ; 
rays variable in length, one longer, about 0:03 mm. long; two 
shorter, about 0:016 mm. long; (4) anchors confined to the lower 
part of the sponge ; shaft from 20-0 to 40-0 by 0-024 to 0-03 mm. ; 
rays, 0°103 by 0:016 mm.; spread 07118 mm.; (5) arculi and 
sigmelle, about 0:0156 mm. long.; (6) globules, 0:0585 mm. in 
diameter. 

Habitat.—Kerguelen, 10 to 150 fms. 


Family 2. THENEIDZ. 


Genus 1. Thenea.—Sponge of symmetrical form, with special- 
ised poriferous areas. The triana are bifurcated forks, with long 
secondary rays; and anchors. ; 

Thenea muricata, Bwk.—Occurs in the northern regions of the 
North Atlantic, not present in the Challenger collection. 


Thenea schmidti, sp. n.—Sponge similar to T. muricata, Bwk., 
but distinguished by the large size of its calthrops spicules, and by 
the comparative thinness of the collenchymatous layer about the 
canal walls; the rays of the calthrops from 0°175 to 0°205 mm. 
long. 

Habitat.—Station tv., lat. 36° 25’ N.; long. 8° 12’ W.; 600 
fms. ; station 73, lat. 38° 30’ N.; long. 381° 14’ W.; 1000 fms. ; 
‘and (O. Schmidt) Florida, 198 fms. 


T. grayi, sp. u.—Sponge with a more or less flattened summit 
and rounded base, which in young forms is hemispherical. Oscule, 


184. Scientific Proceedings, Royal Dublin Society. 


large round, laterally placed, poriferous area, also lateral on the 
opposite side to the oscule: both oscular and poriferous margins 
fringed with long spicules. Rootlets few and slender. Flagel- 
lated chambers, 0:063 mm. in diameter. Spicules—(1) fusiform 
acerate, 10:07 by 0:026 mm., and 78 by 0:08 mm. ; (2) porrectate 
forks, shaft, 5:88 by 0:087 mm.; arms, 0°828 by 0:083 mm.; 
(3) bifurcated forks, shaft, 5°88 by 0:087 mm.; primary rays, 
0:238 by 0:0725 mm. ; secondary, 1:193 by 0:06 mm.; (4) somatic 
anchor, shaft, 1:07 by 0:006 mm. ; rays, 0:048 mm. long; spread, 
0:09 mm.; (5) radical anchor, 10°33 by 0°0175 mm. ; rays, 0°09 to 
0012 mm. ; spread, 0:123 mm. ; (6) calthrops small, with slender 
rays, a single ray, 0°143 mm. long; (7) smaller calthrops of usual 
form; (8) spini-spirule, a stout spiral body, 0:0118 mm. long; 
spines, 0:016 mm. long. Greyish-white. 

Habitat.—Station 164 ¢c., lat. 34° 19’ 8.; long. 157° 31’ E. 
400 fms. 


Thenea wyvillii, sp. n.—Sponge, upper surface rounded, 
cushion-like or flat, with a central, shallow, basin-like depres- 
sion, in which the excurrent canals open by small, numerous, 
oscula. Equatorial margin sharp, thin, without a spicular fringe, 
projecting over the lower surface, which is produced into several 
strong rootlets, ending below in a tangled spicular base. Poriferous 
membrane continuous round the equatorial area. Spicules— 
(1) acerate, 7°85 by 0:07 to 0:084 mm.; (2) porrectate fork, 
shaft, 6°8 by 0:072 mm.; arms, 0°5 mm. long; (8) bifurcate forks, 
distinguished by the crooked form of these shafts, which measure 
4:28 by 0:0968 mm.; primary arms, 0:178 by 0:08 mm. ; secon- 
dary, 0°54 by 0:064 mm. ; (4) somatic anchors, shaft, 0-876 by 
0-008 mm.; rays, 0:95 mm. long; spread 0:1 mm.; (5) radical 
anchors, 18:2 by 0:011 mm.; rays, 0°1 by 0°014 mm.; (6) cal- 
throps, very regular, triradiate and quadriradiate, as well as other 
forms; one ray of a quadriradiate measures from 0:08 to 0:09 by 
00118 mm. ; (7) small calthrops; rays, from 4 to 10 in number, 
about 0:02 mm. long; (8) spini-spirule, a slender spiral shaft, 
and numerous spines, total length, 0:02 to 0-025; length of a 
single spine, 0:004 mm. Yellowish-white. 

Hubitat.—Station 209; lat. 10° 14’ N.; long. 128° 54’ W. 
95 fms. 


Sottas—On Tetractinellid Sponges. 185 
T. fenestrata, O. Schmidt. 3 


T. delicata, sp. n.—Sponge, small symmetrical, a conical upper 
half, sharply defined from a hemispherical lower half; upper 
surface hirsute; oscule apical; flagellated chambers, 0-087 by 
0-067 mm. Spicules—(1) acerate, 6°3 by 0:044 mm.; (2) por- 
rectate forks, shaft, 4:10 by 0:02 mm.; arms, 0°35 mm. long; 
(3) bifurcate forks, shaft, 4°82 by 0°065 mm.; primary rays, 0°143 
by 0:06 mm.; secondary rays, 1:07 by 0:06 mm.; (4) somatic 
anchors, shaft, 0°954 by 0-008 mm.; rays, 0:075 mm. long ; 
spread, 0-876 mm.; (5) anchoring spicules terminate in rounded 
elub-like heads; shaft, 5°35 by 0:04 mm.; head, 0°0645 mm. 
wide ; (6) calthrops few, small, tending to a spiral form; rays, 
0:08 by 0-008 mm.; (7) spini-spirule, shaft short and straight, 
spined at the ends; total length, 0:04 mm. Greyish-white. 

Habitat.—Station, 147., lat. 46° 16’ 8.; long. 48° 27’ W. 
1600 fms. 


T. wrightii, sp. n.—Sponge depressed, a flat or obtusely conical 
upper surface, bearing the oscule; and a flat base ; margin more or 
less lobate ; equatorial recess discontinuous ; forming a number 
of circumscribed poriferous areas. Oscular and poral areas not 
defended by projecting spicules; rootlets absent. The flat cake- 
like form of the sponge is characteristic. 

Habitat.—Station 302, lat. 42° 43’ 8.; long. 82° 11’ W. 
1450 fms. 

Genus 2. Normania.—Sponge without specialized porous areas, 
like those of Thenea ; triana; simple forks, without anchors ; 
quadriradiate spicules, as well as calthrops, occur in the choano- 
some ; mesoderm of the choanosome a collenchyme ; canal! system, 
eurypylous. 

Normania schulsti, sp. n.—A plate-like erect sponge, bearing 
pores on one surface, and oscules on the other; distinguished from 
Normania crassa by the size of its spicules; the acerates, 3°57 
by 0-071 mm.; the forks, shaft, 0-714 by 0°071; arms, 0°357 mm. 
long. 

Habitat.—Station 150; lat. 52° 4’ 8. ; long. 71° 22’ EB. 150 fms. 


NV. crassiuscula, sp. u.—A plate-like sponge similar in character 


186 Scientific Proceedings, Royal Dublin Society. 


of its spicules to WV. schulzii, but distinguished by the course of the 
excurrent canals, which run obliquely and longitudinally upwards 
through the plate to open in patent oscules on one face of the 


late. 
Habitat.—Porto Praya, St. Jago. 100-128 fms. 


NV. goliath, sp. n.—Sponge massive, surface raised into sharp 
undulating ridges, with deep intervening furrows; surface hispid ; 
oscules numerous on the sides and summits of the ridges. Spicules— 
(1) fusiform acerate, 2°475 by 0:08 mm.; (2) calthrops, each ray 
0:684 by 0:05 mm.; (38) acerella, 0°316 by 0:008 mm. ; (4) echi- 
nella, 0°16 mm. long; (5) globules, 0-16 mm. in diameter. 

Habitat.—Station 122; lat. 9° 5’ S.; long. 34° 50’ W. 350 fms. 


NV. laminaris, sp. n.—Sponge, a thin lamellar expansion 4 to 5 
mm. thick; oscules small, dispersed on the inner face. Spicules— 
(1) a stout fusiform acerate, 3:5 by 0°05 mm. ; (2) a slender cylin- 
drical acerate, 5°3 by 0:008 mm.; (3) fork; shaft, 0°678 by 0:06 ; 
arms, 0357 by 0:06 mm.; calthrops, acerella, echinella, and spini- 
spirula also present. 

Habitat.—Amboyna. 


NV. tenuilaminaris, sp. n.—This chiefly differs from the preced- 
ing species by the greater thinness of the wall, which is from 3 
to 3°5 mm. thick. I now only provisionally distinguish it, reserving 
a final decision to the completed report. 

Habitat.—Station 236, lat. 34° 58’ N.; long. 189° 29’ E.; 
238-775 fms. 


_ Genus 3. Vulcanella, ¢. n.—Spicules similar to those of Nor- 
mania; sponge distinguished by the specialisation of the oscula, 
each the large patent opening of a shallow cloaca, which is lined 
by a coarsely fenestrate membrane. 


Vulcanella cribrifera, sp. n.—Sponge egg-shaped, bearing one 
or more large oscules on the upper surface; margins of oscules 
strongly hispid. Spicules—(1) fusiform acerate, 3:04 by 0:067 mm. ; 
(2) slender hispidating acerate, 7-5 by 0-032 mm.; (8) fork, 
shaft, 1:0 by 0-04 mm.; arms, 0°25 by 0-032 mm.; (4) calthrops 


Sornas—On Tetractinellid Sponges. 187. 


(possibly not proper to the sponge), rays from 0°28 to 0-64 mm. 

long; (5) acerella, 0:011 mm. long; (6) spini-spirula, 0-016 to 

0:02 mm.; (7) cylindrical spicules, with rounded ends (sausage- 

shaped), 0:357 by 0:028 mm.; these are confined to the cloaca. 
Habitat.—St. Jago, Porta Praya. 


Genus 4. Characella, g, n.—Similar to Normania, but dis- 
tinguished by the absence of forks in the choanosome; and by 
possessing only one form of flesh-spicule, which is an amphiaster 
form of spini-spirule. 


Characella aspera, sp. n.—Sponge irregular in form; growing 
into irregular ridges, lobes, and folds; oscules numerous ; pores 
generally dispersed or collected within circular depressed areas. 
Spicules—(1) acerate, 1-476 by 0-073 mm.; (2) forks, shaft from 
0-2 to 0-4 by 0:04 to 0:074 mm. ; arms, when simple 0°2 to 0°64 mm. 
long; when bifurcate, primary rays, 0:143; secondary, 0°27 mm. 
long; (3) acerella, 0-4 by 0:008 mm.; (4) amphiaster, 0:0276 to 
0:0434 mm. long; (5) globules 0:05 mm. in diameter. 

Habitat.—Station 122; lat. 2° 5’ S.; long. 84° 50’ W. 350 fms. 


Family.—STELLETTIDZ. 


The genera of the family Stellettida may be arranged in 
sub-families, as follows :— 
A. Stellettides with but one form of stellate. 


1. Sub-family. HOMASTERINA. 


Ectosome not a cortex—Myriastra. 
Ectosome a cortex.—Pilochrota. Asterella. 


B. Stellettides with more than one form of stellate (Heteras- 
terina). 
(a) Both forms are stellates. 


2. Sub-family. STELLETTINA. 


Stellates are the only flesh spicules. 
Without a cortex—Anthrastra. 
With a cortex—Stelletta. 
Trichite sheaves are also present—Dragmastra. 


188 Scientific Proceedings, Royal Dublin Society. 
(5) One form is a stellate, the second a sanidaster. 


3. Sub-family. SANIDASTERINA. 


No other flesh spicules are present—Tribrachium. 
Trichite sheaves are present as well—Tethyopsis. 


(c) One form isa stellate, the second an amphiastrella. 


4. Sub-family. STRYPHNINA. 
A single genus—Stryphnus. 
(d) One form is a stellate, the other a spined bacillus. 


5. Sub-family. PSAMMASTERINA. 


A single genus—Psammastra. 


Although this classification appears to be wholly based on the 
flesh-spicule, it is not so in fact; but it happens as a remarkable 
coincidence that differences in the flesh-spicule are as a rule asso- 
ciated with other and profounder differences in the organism: we 
might easily have brought the latter more prominently forward in 
this classification, but it would have involved more space than we 
can here afford. 


Genus 1. Myriaster.—Sponge small; oscules distinguishable 
from pores; ectosome thin, mainly collenchymatous, excavated by 
widely extending sub-dermal cavities, which are never restricted to 
form chones. Flesh spicules, chiasters only. (‘The chiaster is a 
small stellate, with an excessively minute centrum, hair-like rays 
either abruptly truncated at the ends, or capitate; usually few in 
number. ‘The typical forms, with few rays and capitate ends, may 
be fancifully supposed to represent the Greek letter x, hence the 
name chiaster). ‘The mesoderm is a sarcenchyme, the flagellated 
chambers small, usually about 0:02 mm. in diameter; they open 
by short abiti into the excurrent tubes. Distribution chiefly in 
Australian seas. 

Myriaster subtilis, sp. n.—Sponge small, lobate; a few small 
oscules. Spicules—(1) acerate, 1°35 to 1:5, by 0°082 mm.; (2) fork ; 
shaft, 1:2 by 0:04 mm.; rays bifurcate ; primary rays, 0°042; 
secondary, 0:16 mm. long; (3) anchor, shaft, 1:16 by 0:°012 mm. ; 


Sortas—On Tetractinellid Sponges. 189 


rays, 0°04 mm. long ; (4) chiaster ; rays capitate, 0:008 to 0:016 mm. 
in diameter. 
Habitat.—Kobei, Japan. 8 to 50 fms. 


Myriaster simphicifurca, sp. n.—Sponge small; a single oscule 
on upper surface. Spicules—(1) acerate, 2:0 by 0:0316 mm. ; 
(2) fork, shaft, 2°325 by 0-055 mm.; arms, simple, 0:37 by 
0:054 mm.; (3) anchor, shaft, 1:86 by 0:03 mm.; rays, 0:12 mm. 
long; (4) chiaster, 0:012 mm. in diameter. 

Habitat. —Station 186, lat. 10° 30’ 8. ; long. 142° 18’ E. 8 fms. 


Myriaster toxodonta, sp. n.—Sponge small ; a few small oscules. 
Spicules—(1) acerate, 3°42 by 0:032 mm. ; (2) fork, shaft, 3-5 by 
0°05 mm; arms, bifurcate; primary rays, 0:095 to 0:127 mm. 
long; secondary, 0-29 to 0°32 mm. long; (8) anchor, shaft, 3°6 by 
0-024 mm. ; rays, 0'1114 mm. long ; (4) chiaster, 0°01 to 0:°016 mm. 
in diameter. | 

Habitat.—Station 208, lat. 11° 6’ N.; long. 123° 9’ EK. 20 fms. 


Myriaster clavosa, Ridley. 
Habitat.—Stations 186 and 208. 


Myriaster quadrata, sp. u.—Sponge small, a single small oscule. 
Spicules—(1) acerate, 2°56 by 0016 mm.; (2) fork, shaft, 3-2 by 
0028 mm.; arms, bifurcate; primary rays, 0:11 mm., secondary 
rays, 0°27 mm. long; (3) anchor, shaft, 3:14 by 0:02 mm.; rays, 
0-1 mm. long; (4) chiaster, 0-008 mm. in diameter. 

Habitat.—Station 212, lat. 6°54’ N.; long. 122°18’ E. 10 fms. 


Genus 2. Pilochrota, g. n.—Oscules distinct, pores in sieves 
overlying incurrent chones; ectosome, thick fibrous cortex; flesh 
spicules, chiasters; choanosome, as in Myriaster. Distribution : 
Australian seas, Tahiti, West Indies, 8. Atlantic. 

Pilochrota haeckeli, sp. n.—Sponge sub-globular ; oscule single. 
Spicules—(1) acerate, 2°07 by 0-046 mm.; (2) fork, shaft, 2°18 by 
0:055 mm.; arms, simple, 0:24 to 0:32 mm.; (8) anchor, shaft, 
3°03 by 0:035 mm.; rays, 0°16 mm. long; (4) small acerate of the 
cloaca; (5) chiaster, 0:016 mm. in diameter. 

Habitat.—Zamboanga. 10 ims. 


190 Scientific Proceedings, Royal Dublin Society. 


- P. anancora, sp. n.—Sponge small, spherical, depressed, oscule 
single. Spicules—(1) acerate, 1°68 by 0:023 mm., to 3:18 by 
0:023 mm.; (2) fork, shaft, 1°63 by 0:0276 mm. ; arms, simple, 
0127 mm. long; (8) chiaster as usual. 

Habitat.—Bahia. 7-20 fms. 


P. gigas, sp. u.—Sponge massive ; several large oscules on the 
upper surface. Spicules—(1) and (2), 3-18 by 0-024 mm. ; acerate, 
1:7 by 0:039 mm.; (8) fork, shaft, 1:96 by 0-039 mm.; arms, 
0-223 mm. long; (4) chiaster, capitate rays, 0°013 mm. in dia- 
meter. 

Habitat.—St. Paul’s Rocks. 


P. tenuispicula.—Sponge small, oscule single. Spicules— 
(1) acerate, 1:35 to 2°3, by 0°016 mm.; (2) fork, shaft, 1:6 by 
0-016 mm. ; arms, 0°12 mm. long; (38) chiaster; rays not capitate, 
0:012 mm. in diameter. 

Habitat.—Bermuda, W. Indies, 


P. pachyderma, sp. n.—Sponge massive, lobate, free, two or 
more oscules on the upper surface; cortex very thick. Spicules— 
(1) acerate, 1:193 by 0:0178 mm.; (2) fork, shaft, 1:114 by 
0:022 mm.; arms, simple, 0:12 mm. long; (3) anchor, shaft, 1°35 
by 0:0158 mm. ; rays, 0-067 mm. long; (4) chiaster, rays abruptly 
truncate, but not capiate, 0:006 to 0-011 mm. in diameter ; colour, 
purplish. 
 Habitat.—Tahiti. 30-70 fms. 


P. crassispicula, sp. n.—Sponge irregularly spherical ; free ; 
oscule single. Spicules—(1) acerate, 3°5 by 0:°024 mm., and 2:3 
by 0:052 mm. ; (2) fork, shaft, 2°36 by 0:08 mm. ; arms, 0:254mm. 
long; (8) chiaster, rays capitate; from 0-012 to 0-02 mm. in 
diameter. | 


Habitat.—Bahia. 7 to 20 ims. 
P. purpurea, Ridley. 


P. longancora, sp. n.—Sponge small; a single circular oscule, 
having the margin fringed by minute acerates projecting radiately 
in the plane of the apertures. Spicules—(1) acerate, 1:63 by 


Soritas—On Tetractinellid Sponges. ‘191 


0°085 mm. ; (2) fork, shaft, 2:1 by 0:047 mm. ; arms, simple, 
0°35 mm. long; (38) anchor, shaft, 3°56 by 0:024 mm.; rays, 
0075 mm. long; (4) minute acerate of oscular margin; (5) chias- 
ter, 0:009 mm. in diameter in the ectosome, 0:012 mm. in choano- 
some. 

Habitat.—Torres Straits. 3-11 fms. 


Genus 3. Anthastra, g. n.—Sponge usually more or less 
spherical ; oscules distinguishable from the pores or not; ectosome 
thin, chiefly collenchymatous, excavated by extensive sub-dermal 
cavities which never form chones; choanosome as in Myriaster. 
Flesh spicules an anthaster and usually a chiaster. (The anthaster 
is a stellate with conical or bacillar microspined rays, which may 
be numerous but are usually few in number, and may be reduced 
to two, when a spined bacillus is the result.) Distribution: 
Australian seas, and Japan. 

Anthastra communis, sp. n.—Sponge more or less spherical, free 
or attached ; oscules not distinguishable from the pores. Spicules 
—(1) acerates 4:2 to 5:6 by 0:06 to 0-09 mm. (2) fork with bifur- 
cated arms, primary rays projecting forwards and outwards, some- 
times more outwards than forwards, sometimes the reverse, then 
giving the head a cyathi-form appearance, secondary rays horizon- 
tal, shaft, 4:4 to 5:7 by 0:09 to 0-11 mm.; primary rays, 0°14 to 
0-16; secondary, from 0°52 to 1:114 mm. long; (8) anchor, shaft, 
3'0 to 43 by 0°32 to 0°39 mm.; rays, 0°127 to 0:16 mm. long. ; 
(4) anthaster, rays few, 0:02 to 0:03 mm. long; (5) chiaster, spines 
numerous, 0:006 to 0:008 mm. long; colour, greyish-white, some- 
times russet-red (owing to presence of algal cells ?). Baers 

Habitat.—Station 162, lat. 39° 10’ 30” S.; long. 146° 37’ E.; 
388 fms. Station 162a; lat. 36° 59’ 8.; long. 150° 20’ E.; 150 
fms. Port Jackson, 6 to 15 ims. 


Anthastra pulchra, sp.n.—Sponge small, globular, free, a single 
oscule. Spicules—(1) acerate, 2:4 to 3°1 by 0:0315 mm.; (2) fork 
with simple arms, shaft, 2°6 to 2-9 by 0:0474 mm.; arms, 0:26 
mm. long; (3) anchor, shaft, 2°6 to 2:9 by 0:0315 mm.; rays, 
0:125 mm. long; (4) anthaster, rays few, 0:016 mm. long; 
‘O) chiaster, variable in character, rays seldom capitate. 

Habitat.—Station 163a.; lat. 36° 59’ S.; long. 150° 20’ E. 
150 fms. | 


192 Scientific Proceedings, Royal Dublin Society. 


Anthastra parvispicula, sp. n.—Sponge small, spherical, free, a 
single small oscule. Spicules—(1) acerate 1:3 by 0-02 mm.; 
(2) fork with simple arms, shaft, 1°75 by 0:02 mm.; arms, 0°21 
mm. long; (3) anchor, shaft, 1:3 by 0016 mm.; rays, 0:045 mm. 
long ; (4) anthaster as in A. pulchra ; (5) chiaster, rays not capitate, 
0:0118 mm. long. 

Habitat.—Station 161; lat 38° 21’ 30” 8.; long. 144° 36’ 30” H. 
30 fms. 


Genus 4. Ecionema, Bwk.—Similar to Anthastra, but with the 
oscules confined to the summit, the excurrent tubes running longi- 
tudinally and vertically through the sponge. 

Ecionema ridleyi, sp. u.—Sponge ovate, several small oscules 
on the summit. Spicules—(1) acerate, 4:07 by 0118 mm. ; 
(2) fork, with simple arms, 4:3 by 0118 mm.; arms, 0:27 to 
0°32 mm. long; (8) anchor, shaft, 3:6 by.0:03 mm.; rays, 
0:103 mm. long; (4) anthaster, small; rays few or numerous; a 
single ray of a tetrad form, 0-01 by 0:004 mm. ; (5) chiaster, rays 
slender, hair-like, capitate, 0'016 mm. in diameter. 

Habitat.—Port Jackson. 30-35 fms. 


Ecionema pyriformis, sp. n.—Sponge obconic, attached by flat 
base, summit bearing numerous small oscules; pores in sieves, 
generally distributed over the sides ; chief excurrent canals vertical. 
Spicules—(1) acerate, 3°14 by 0°095, to 4 by 0104 mm. ; (2) fork, 
shaft, 3°02 by 0:095, to 3°72 by 0°163; arms bifurcate ; primary 
rays, 0°1114, secondary rays, 0-1114 to 0-175 mm. in length ; 
(3) anchor, shaft, 2°1 by 0°023 mm. ; rays, 0:016 mm. long; 
(4) anthaster, bacillary rays with rounded ends, microspined, 
usually 4 to 7 in number; a single ray of a tetrad form, 0:013 by 
0:004 mm.; (5) chiaster rays capitate, 0°008 mm. long. 

Habitat.—Port Jackson. 30 to 35 fms. 


Genus 4. Stelletta, Schmidt.—Hctosome a thick cortex, 
traversed by chones. Spicules, two kinds of stellates, one with 
conical pointed rays. 

Stelletta phrissens, sp. n. Kneis, globular or cylindrical, 
attached ; surface hispid, with spicules which project 6 to 7 mm. 
beyond it; oscules small, congregated ; pores in sieves; cortex thick, 


Sottas—On Tetractinellid Sponges. 193 


the outer collenchymatous layer without spicules. Spicules— 
(1) acerate, 4°75 by 0:07 mm.; (2) fork, shaft, 3:5 to 4:2, by 
0-12 mm.; rays bifurcate; primary rays about half the length of 
secondary, which are 0°3 mm. long; (3) anchor, shaft, 8°72 by 
0:06 mm.; (4) stellate sharp conical rays, small centrum; rays 
from 0:02 to 0-027 mm.; (5) pycnaster, a comparatively large 
centrum, provided with numerous short spines, with truncated 
ends, 0:01 mm. in diameter. 

Habitat.—Station 308, lat. 50° 8’ 30” §.; long. 74° 41’ W. 
175 fms. 


Genus 5. Astrella, g. n.—Like Stelletta, but with only one 
form of stellate, a pycnaster, i.e. with a small centrum, and short 
blunt, numerous, rays. | 

Astrella vosmaert, sp. n.—Sponge, beehive-shaped, oscules not 
distinguishable from the pores. Spicules—(1) acerate, 3-14 by 
0:06 mm.; (2) fork, shaft, 3:02 by 0:08 mm.; arms bifurcate ; 
primary rays, 0-088, secondary, 0-24 mm. long; (8) anchor, shaft, 
3°61 by 0:028 mm; arms, 0:04 mm. long; (4) pyenaster, a com- 
paratively large centrum and short, thick, truncated rays, 0-012 to 
0:016 mm. in diameter. 


Genus 6. Dragmastra.—Like Stelletta, but with a layer of 


trichite sheaves in the cortex. Type, Dragmaster (Stelletta) 
normant (Sollas), Norway. 


Genus 7. Stryphnus, g. n.—Stellettidee distinguished by the 
absence of a radiate arrangement of the spicules of the choanosome, 
only those which immediately approach the surface of the sponge 
being arranged at right angles to it; by the comparatively small 
size and rarity of the fork spicules as compared with the acerates, 
and chiefly by the presence of a curious irregular flesh-spicule— 
the amphiastrella. The cortex is a vesicular collenchyme contain- 
ing pigment cells. 

Stryphnus niger, sp. n.—Sponge, compound, massive, oscules 
large, collected in groups. Spicules—(1) acerate, 2:4 by 0-61mm. ; 
(2) fork, shaft, 0-446 by 0:0356 mm.; arms bifurcate; primary 
rays, 0:055, secondary, 0°079 mm. long; (3) anchors; (4) stellate, a 
small centrum and numerous slender conical-shaped pointed rays, 
0:014 mm. long; amphiastrella, various, typically a short cylin- 


SCIEN. PROC. R.D.S.—VOL. V. PT. IV. P 


194 Scientific Proceedings, Royal Dublin Society. 


drical shaft with a whirl of spines at each end; the spines may 
be sharp, but are more usually stunted and rounded off, or the 
spines may be given off quite irregularly from all parts of the 
shaft; 0:016 by 0:012. Colour, deep puce black. 

Habitat.—Port Jackson. 30-835 fms. 


Stryhnus unguicula, sp. u.—Sponge similar to 8. niger. Dis- 
tinguished by the forks, the arms of which are bifurcate, with the 
primary rays extending, only slightly forward, and the secondary 
rays diverted backward ; each pair of the latter, also, after diverg- 
ing from each other in the usual way, are approximated so as to 
run parallel to each other for the last half of their course ; shaft, 
0508 by 0:°032 mm.; primary rays, 0°0276, secondary rays, 
0:04 mm. long. 

Habitat.—Port Elizabeth, 8. Africa (not in Challenger Collec- 
tion). 


Genus 8. Tribrachium, Weltner.—Sponge, a spherical body, 
produced into an excurrent tube, but not into a special incurrent 
tube. Spicules—forks, with only two arms in the excurrent tube, 
with three arms in the cortex of the body ; acerates, anchors, rarely 
stellates, and numerous sanidastra. 


Genus 9. Tethyopsis, Stewart.—Sponge, a special poral tube 
at one pole of the spherical body and a special oscular tube at the 
other; canal system arranged on a radiate plan, primitively four 
excurrent canals, alternating with four incurrent canals. Spicules— 
reduced forks in the excurrent tube; forks with three arms, or only 
two or one in the cortex of the body, acerates, but no anchors; 
in the poral tube acerates, no forks or anchors; flesh-spicules are 
stellates, sanidastra, and trichite sheaves. 


Genus 10. Psammastra, g. n.—Sponge, with a thick fibrous 
cortex incorporating grains of sand; oscules, two or more; surface 
raised into conuli; spicules—a stellate with short rays and large 
eontrum, and another form with smaller centrum and larger rays, 
also, and most numerous spined bacilli ; forks of very peculiar 
character, rays very short, appearing merely as spines of an 
acerate spicule with a rounded distal end. 


— Sottas—On Tetractinellid Sponges. 195. 


Psammastra murrayi, sp. u.—Sponge spherical, with two or 
_ three oscules; surface raised generally into conuli, and produced 
here and there into strong fibrous bands for attachment; cortex 
thick, containing imbedded grains of sand. Spicules—(1) acerate, 
4:65, and over, by 0-065 mm. ; (2) fork, 3:9 by 0-071 mm.; arms 
simple, regularly curved outward and forward, 0-097 to 0:116 mm. 
long ; spread, 0-161 to 0°175 mm.; (8) modified fork; a conical 
spicule, with rounded distal base, and three short spines given off 
near the distal end; the axial ray of the spines descends outwards 
and downwards through the spicular shaft, but bends into hori- 
zontal position as it enters the rays or spines, which may be simple 
or bifurcate, the bifurcation taking place in a horizontal or vertical. 
plane; (4) stellates, a variety with large centrum and short rays, 
0-012 to 0.616 mm. in diameter, passing into a second variety 
with small centrum and longer rays, 0-016 to 0-024 mm. in dia- 
meter; (5) bacillus, a cylindrical rod with rounded ends, micro- 
spined irregularly over the whole surface; sometimes constricted 
in the middle, 0:018 to 0:016 by 0:004mm. Colour, russet brown 
on upper surface where exposed to the light ; pale grey below. 

Habitat.—Station 162, lat. 39° 10’ 30” 8.; long. 146° 37’ BE. 
38 fms. 


Family. GEODINIDZ. 


Genus 1. Erylus, Gray. Genus 4. Synops, Vosmaer. 
» 2 Caminus, Schmidt. 5, 0. Isops, Sollas. 
» 98 Cydonium, Miller. » 6. Geodia, Lamk. 


Of the genus Geodia no examples occur in the Challenger 
Collection. 

Synops is an exceedingly natural genus, characterized, not only 
by the restriction of the oscules to one surface, but also by the 
general characters of its spicules; anchors rarely occur, and the 
arms of the forks are usually simple. 


DEscRIPTION OF SPECIES. 


Lrylus formosus, sp. n.—Sponge massive, growing into ridges 
and lobes, attached ; oscules round, few; pores large, each the 
simple opening of an incurrent chone. Spicules—(1) acerate, 
0-9 by 0:°024 mm. ; (2) fork, shaft, 0-4 by 0:024 mm. ; arms simple; ~ 

P2 


196 Scientific Proceedings, Royal Dublin Society. 


(3) globate, shaped like a finger biscuit, or shuttle-shaped, or 
lozenge-like, surface granulated, 0-14 by 0-032, to 0°175 by 
0:026 mm., or narrower and longer, 0:2 by 0°024, or shorter and 
wider, 0122 by 0:048 mm. ; thickness, from 0:008 to 0°01 mm. ; 
(4) fusite, 0:07 by 0:006 mm. ; (5) large stellate, with few rays, 
0:063 mm. in diameter, a single ray, 0°032 mm. long; (6) small 
stellate, a small centrum, and numerous short rays, truncated, or 
capitate at the ends, 0°016 mm. in diameter. 
Habitat.—Bahia. 7-20 fms. 


Caminus spheroconia, sp. n.—Sponge massive, with massive 
vertical lobes, attached ; oscules on summits of lobes, large, leading 
into large cloacas; pores in sieves, roofing incurrent chones. 
Spicules—(1) acerate, 0°5 by 0:016 mm.; (2) fork, shaft, 0°32 by 
0°016 mm.; arms simple, 0:2 mm. long; (3) globate, 0°0553 mm. 
in diameter ; (4) globule, a minute, smooth sphere, 0°004 mm. in 
diameter ; this serves both as ectaster and endaster ; colour, purplish 
when exposed to the light; yellowish below. 

Habitat.—Bahia, shallow water. 

This sponge is very similar to Caminus vulcani, O. 8., which 
also contains true forks and globules; it differs by the absence of 
stellates, which are present in C. vulcani, and by the less length of 
its acerate spicules (0:08 by 0:016 mm. in C. vulcani), and by the 
smaller size of the globule (0.1 mm. in diameter in C. vulcani). 
The cortex is about 0:8 mm. thick, and consists of an ecto-cortex 
formed of vesicular tissue, 0°05 to 0°24 mm. thick, of a globate 
layer, 0°65 mm. thick, and an inner fibrous layer, 0-05 to 0:08 mm. 
thick. 


— Cydonium glariosus, sp. n.—Sponge, more or less spherical, 
attached ; the collenchymatous ecto-cortex is crowded with coarse 
grains of sand, and traversed by pencils of short acerates, which are 
entirely confined to it. Spicules—(1) acerate, 1°86 by 0-026 mm. ; 
(2) small acerates of the cortex, 0°35 to 0:4, by 0:016 mm. ; (3) fork, 
shaft, 2°86 by 0:052 mm. ; arms simple; (4) second form of fork, 
shaft, 5°36 by 0:03 mm.; arms simple, 0:08 to 0:11 mm. long; 
(5) anchor, shaft, 4:65 by 0°012 mm.; rays, 0:08 mm. long ; 
(6) globate, spherical, 0:05 to 0:058 mm. in diameter ; (7) ectaster, 
small centrum, short rod-like rays, 0:01 mm. diameter; (8) en- 


Sottas—On Tetractinellid Sponges. 197 


daster, centrum small, rays conical pointed, or rod-like truncated, 
0-016 to 0:0193 mm. in diameter. Colour, purplish white. — 
Habitat.—Bahia. 7 to 20 fms. 


Cydonium magellant, sp. u.—Sponge large, attached ; surface 
hispid. Spicules—(1) acerate, 3-93 by 0:052 mm., to 2°71 by 
0-058 mm. ; (2) fork, shaft, 3:93 by 0:064, to 4:82 by 0:09 mm. ; 
arms bifurcate; primary rays, 0°13, secondary, 0°275 mm. long ; 
(3) anchor, shaft, 7-4 by 0°02 mm. ; rays, 0°15 mm. long; (4) glo- 
bate, spherical, depressed, 0:123 by 0:103 mm.; (5) ectaster; a 
fairly large centrum, numerous rod-like rays, 0°0118 mm. in 
diameter ; (6) endaster, a globo-stellate, 0-217 mm. in diameter. 

Habitat.—Stations 308 and 3811. 175 and 245 fms. 

Cydonium hirsutus, sp. n.—Sponge irregular lobate; surface 
hispid, spicules projecting 8 or 9 mm. beyond it, cortex thick. 
Spicules—(1) acerate, 4:5 by 0:06 mm. to over 9:0 by 0-032 mm.; 
(2) fork, shaft over 4-46 mm. long by 0:084 to 0°05 wide; arms 
bifurcate, primary arms, 0:13; secondary, 0°35 mm. long; 
(3) second form of fork, shaft long, diameter, 0°2 mm., arms 
simple 0:18 mm. long; (4) anchor, shaft, long, 0:°018 mm. in 
diameter; rays, 0:036 mm. long; (5) glohate, a flattened prolate 
ellipsoid: 0-306 by 0:245 by 0-161 mm.; (6) ectaster, a small 
centrum, and blunt conical rays, 0012 mm. in diameter ; (7) en- 
daster, a small centrum, and a few slender conical rays, 0:02 mm. 
in diameter: a small globo-stellate is present, but does not belong 
to the sponge. 

Habitat.—Station 192; lat. 5° 49'15” 8. ; long. 182° 14° 15” W.; 
140 fms. 


Synops vosmaeri, sp. u.—Sponge cylindrical, a cup-shaped 
depression at the summit, erect, attached, oscules confined to the 
summit; pores in sieves on the sides, roofing incurrent chones. 
The ecto-cortex contains ectasters scattered throughout it; the 
globate layer is thin, and the fibrous layer remarkably thick. 
Spicules—(1) acerate, from 1:3 by 0:016 to 1-7 by 0-008 mm. ; 
(2) acerate of the cortex, 0°3 by 0:004 mm.; (8) fork, shaft, 1-1 
by 0:039 mm.; arms, simple, 0:29 mm. long; (4) globate, small, 
spherical, 0°04 mm. in diameter; (5) ectaster, a small centrum, 
short spines, with rounded ends, 0:004 mm. in diameter; (6) en« 


198 Scientific Proceedings, Royal Dublin Society. 


daster, long hair-like rays, not numerous, 0-026 mm. in dia- 
meter. 
Habitat.—Station 122; off Barre Grande. 350 fms. 


Synops nitidus, sp. u.—Sponge plate-like, horizontal, oscules 
numerous, small, restricted to the upper surface over which they are 
dispersed ; pores in sieves on the opposite surface; cortex—beneath 
the epithelium is a layer of small globo-stellates, this is sueceeeded 
immediately by the globate layer, which constitutes almost the 
whole of the cortex. Spicules—(1) acerate 1:25 by 0°026 mm.; 
(2) fork, shaft, 1:07 by 0°039 mm., arms simple, 07183 mm. long; 
(3) ectaster, a globo-stellate, 0'0135 mm. in diameter ; (4) endaster, 
a small centrum, and long conical microspined rays, usually few 
in number, 0°044 in diameter. 

Habitat.—Port Jackson, Sydney. The smooth, shining, upper 
surface is very characteristic, and no other species of Synops presents 
the same horizontally spreading form. 


Synops neptuni, sp. n.—This is the largest, tetractinellid sponge 
known. It has the form of a somewhat conical cup with a large 
central cavity, rising from a base of 12 cm. diameter to a height 
of 40 cm.; where broadest its diameters are 22 cm. and 31 cm. 
Its wall is intricately folded. The oscules are confined to the 
inner surface of this cup. 

Habitat.—Station 122; off Brazil. 32 fms. 


Isops pachydermata, sp. u.—Sponge, irregular, massive ; surface 
smooth ; oscules and pores singly perforating small rounded bosses ; 
cortex thick, constituted almost entirely of the globate layer; 
beneath the epithelium a layer of globo-stellates. Spicules— 
(1) acerate, 1:96 by 0:052 mm. ; (2) fork, shaft, 1:07 by 0:039 mm. ; 
arms simple, 0°27 mm. long; (8) globate, a compressed ellipsoid, 
0:24 by 0°19 mm. in diameter; (4) ectaster, a globo-stellate, 0-016 
in diameter; (5) endaster, centrum small, spines conical, sharply- 
pointed, tew; single ray of a triad form, 0-064 mm. long; (6) a 
stellate intermediate between (4) and (5). 

Habiiag —Station 56; lat. 32° 8’ 45” N.; long. 64° 59’ 35” W. 
1075 fms 


Sortas—On Tetractinellid Sponges. 199 


DEFINITION oF TERMs. 


Ectosome.—The outer layer of the sponge, not containing 
flagellated chambers. 


Choanosome.—The “mark” or “parenchyma,” distinguished 
by the presence of flagellated chambers. 


Eurypylous.— When the flagellated chambers communicate by 
wide mouths directly with the excurrent canals. 


Aphodal.—When they do so by narrow canaliculi. 
Collenchyme.—Gelatinous connective tissue. 


Sarcenchyme.—A. collenchyme in which the codlenchytes or branch- 
ing stellate cells are replaced by granular polygonal contiguous 
cells. 


Triana.—Tetrad spicules with a differentiated shaft—forks, and 
anchors. 


[ 200 |] 


XXV.—IRISH METAL MINING. By G. H. KINAHAN, 
M.R.I.A., Ere. 


[Read, March 24, 1886.] 


Tue lists of mines published by Griffith in the Dublin Quarterly 
Journal of Science (1861) were corrected and revised in chap. XXI. 
section v. pp. 361, &e., of the Geology of Ireland (1878) ; but these 
now require revision. Itis therefore proposed to again revise and, 
at the same time, to re-arrange them, first giving separate lists for 
each mineral arranged in counties, or in “fields” where the ores are 
bedded, with, subsequently, short County Histories of the mines, 
thus dividing the subject into two parts. 

In both parts the Counties, as far as possible, will be arranged 
alphabetically. In Part I. the lists include all the places where 
the different minerals are recorded as found in appreciable quanti- 
ties ; and in Part II., when possible, the present state of the lodes 
will be stated ; butin both Parts, in the majority of cases, the infor- 
mation given as to the work done, on account of the unsatisfactory 
way in which the old mining records and statistics were kept, will 
be on hearsay evidence. ‘The statements, therefore, cannot be 
taken as perfectly satisfactory, as a large portion may require to 
be substantiated. 

The history of the early Irish mining adventures is very scant, 
the records being vague. The ancient mines are referred to by 
Griffith, Kane, and other modern explorers; but necessarily the 
remarks had to be more or less vague, and do not give much infor- 
mation. Griffith, however, states :—‘‘ Many of our mining exca- 
vations exhibit appearances similar to the surface workings of the 
most ancient mines in Cornwall, which are generally attributed to 
the Phoenicians.” 


Krnanan—Irish Metal Mining. 201 


The late R. Rolt Brash published an interesting Paper on 
“The Precious Metals and Ancient Mining in Ireland” (Journal 
Roy. His. Arch. Ass. Ireland, vol. i., fourth series, p. 509) ; but it 
more particularly refers to the “finds” of gold and silver articles ; 
these metals having been worked and mined at an early date. 
Bronze implements are also very ancient, and possibly iron; but the 
latter metal corrodes away so fast that all ancient implements must 
have disappeared long since; though traces of them may sometimes 
be found. It may be mentioned;that deep down among the records 
of the earliest inhabitants of the large crannog in Lough Rea, Co. 
Galway, I found a rod of rust that evidently was the remains of 
an iron implement; it must have been 2000, or 3000, or more, 
years old. 

Of Ancient Metal Mining, or its Adjuncts.—A. very early record 
occurs in the Annals of the Four Masters, a.M., 3656, where gold is 
mentioned as procured in Foithue Airthir Liffe, or in the moun- 
tains of Dublin and Wicklow; while at Lyra, Knockmiller, about 
two miles southward of Woodenbridge, Co. Wicklow, the ancient 
timberings in a placer mine were found. We also learn from the 
Annals that in a.m. 3817 silver shields were made at Argetios 
(Silverwood) on the Nore, Co. Kilkenny. In this neighbourhood 
are the remains of ancient mines at Ballygallion and Knockadrina— 
places at which in recent years native silver has been found. It 
appears probable that, in those early times, some at least of the 
silver was procured at those mines; there are, however, other 
prehistoric mines that probably were also sources from which silver 
was procured. There is also mentioned in the Annals ; silver, 
got at Rosargid (which also means Silverwood), near Toomavara, 
Co. Tipperary. That name has not descended to us; but at 
Garrane, adjoining Kilnafinch, a little southward of Toomavara, 
is the debris of an ancient mine, locally called the “Silver Mine.” 
Further westward, south of Nenagh, are the village and mines of 
Silvermines. Some of the mines at this village were worked so 
long ago, that when opened, about the year 1860, the attals ( pyrite 
and sphalerite) in the stulls and old levels were found to have 
undergone a complete chemical change—into peroxide of iron, with 
carbonate and silicates of zinc. In recent years some of the lead 
from this locality has given as much as eighty ounces of silver 
to the ton, in addition to some native silver. Still, further west- 


202 Scientific Proceedings, Royal Dublin Society. 


ward, at Garrykennedy, on Lough Derg, “old men’s workings” 
were broken into about the year 1855, and in them were found a 
man’s skeleton and the remains of wooden and stone tools. To 
the westward of the Shannon, at J/ii/town, near Tulla, Co. Clare, a 
mine was worked in ancient times. Here there is native silver; 
the oaken shovels and large iron picks found suggesting that 
the workings were not as old as some of the others. At Carhoon, 
near 'Tynagh, Co. Galway, there are the relics of an ancient mine 
of which the traditions are extinct. In south-east Ireland, at the 
Magpie or East Cronebane (Ovoca), Co. Wicklow, there are “old 
men’s workings,” on the “ gossan lode,” and in them were found 
stone and wooden implements. Here native silver was also found. 

From so many of these ancient mines being on silver-lead 
lodes, it may be suggested that the “old men” understood a 
process for separating the silver from the lead. 

Nennius, who wrote in the ninth century, mentions the mines 
of Lough Leane, Millarney ; while about the year 1804, when Col. 
Hall was working the lead mine at Ross Island, he found primitive 
levels, stone implements, and other records of ancient work. 

At Derrycarhoon, near Ballydehob, Co. Cork, in an old work- 
ing, there were wooden and stone implements, a curved tube of 
oak, and a primitive ladder—the latter being an oak pole, with 
rude steps cut in its sides. This working must have been very 
ancient, as when found all traces of the surface entrance were 
smothered up by a growth of peat, over fourteen feet deep; this 
ought to represent a period of, at the least, 3000 years or more. 

About the year 1850 wooden tools, shod with iron, were found 
in ancient galleries, in connexion with the coal seam of the Bally- 
castle coal-field, Co. Antrim; while wooden scoops were found in 
an old working for bog-iron in the Queen’s County, some of them 
being now in the Royal [nish Academy Museum. 

During the rush after Irish mines, about twenty-five or thirty 
years ago, their characters were considerably prejudiced, and the 
working of them retarded, by a class of ‘‘ Promoters,” who mis- 
represented them; also by incautious Analysts, who represented the 
ores more favourably than they were entitled to. Such proceed- 
ings are most damaging to a mine; for although it may be good of 
its kind, and be capable of paying well, if judiciously worked, 
when it cannot give the “riches” promised, it gets into disrepute; 


Kinanan—On Irish Metal Mining. 203 


or, if it is injudiciously over-worked, to try and keep up its fic- 
titious character, it will be robbed and its future prospects ruined. 

In the history of the mining during those years, it is now well 
known, that more than one Promoter exhibited specimens as repre- 
senting the ordinary minerals of a lode, while in reality his 
sample exhausted all the mineral of that class to be found in the 
veins. Also, some Analysts, after examining a specimen, allowed 
their analyses to be published as if they were the representative 
analyses, although they were ignorant whether the portion submit- 
ted to them was a true specimen, representing the average ore of the 
lode, ora picked one that only represented its riches. An honest, 
true representation of the value of the minerals of a lode is most 
important, and the neglect of such, or the intentional misrepre- 
sentation of the value of the lode, has led to most disastrous 
results, not only in Ireland, but all over the world. Careless 
analysts and intentional misrepresentations cannot, therefore, be 
too highly censured. 

In drawing out the lists of Irish mines and minerals the pro- 
ducts have been arranged in the following order :—Gold, tin, 
native silver, lead and zinc, copper, sulphur ores and gossen, 
barytes, iron, manganese, antimony, arsenic, cobalt, graphite, 
nickel, titanium, molybdenite, alum and copperas, apatite, salt 
and gypsum, steatite and pyrophylhte: the products being ar- 
ranged as much as possible in regard to the natural grouping of 
the ores in the veins. 

Some of the minerals in the above list Hage been very spar- 
ingly looked after, and their occurrence may be much more fre- 
quent than is inaraetieen mentioned, as the lists are compiled from 
the localities observed and recorded by the different explorers. 
This may be specially the case in reference to some minerals that, 
although observed, have not been recorded. Boate, in his notice 
of the silver mines, Co. Tipperary, records quicksilver as found 
prior to 1640. In modern times no trace of this ore is recorded. 

Some of the Irish rocks are said to be Pre-Cambrian, but the 
only pretension for classing them as Laurentians is their litho- 
logical characters. Some ot these so-called Pre-Cambrian, both 
Petrologically and Palsontologically, are evidently, in one case 
Ordovician and in another Cambrian; while elsewhere they appa- 
rently belong to one or other of these periods. 


204 Scientific Proceedings, Royal Dublin Society. 


In the Lists the Names used for the Geological Groups are 
those given in the following Table :— 


TABLE OF GEOLOGICAL STRATA. 


Names. REMARKS. 
5 g Pliocene. 
N 
Lam [ee] fo) e 
Hog Miocene. 
AA < 
a © | Eocene. 
2 3 Cretaceous. 
A g 9 
Zz o Of Jurassic. 
Oo nn 
is) te! 
wn a | Triassic. 
Permian. Passage beds. 
mn 
; | 22 Carboniferous. Coal Measures and Limestones, &c. 
= = D 2 
° R 
3 > Devonian. Passage beds (Yellow and Old 
A los sal ye Red Sandstone). 
< {| 5°4¢ Silurian. Upper Silurian. 
e| ea 
a Mayhill Sandstone or Llandovery.| Passage beds. 
ral an ie f b 
& | -8-=4 Ordovician. Cambro- or Lower Silurian. 
S| Eco : 
s Arenig beds. Passage beds. 
H 
o@ ss 4 
E = | Cambrian, Primordial appears to be preferred 
Hn or on the Continent and in America. 
Primordial. 


The Passage beds, Arenig and Devonian, are complete in the 
Trish strata ; the others, Mayhill Sandstone and Permian, are only 
in part represented. (See “ Irish Lower Paleozoic Rocks,” Scien. 
Proc. R. D. S., vol. 111., p. 34, May, 1885.) 


Kinanan—On Irish Metal Mining. 


205 


Pazt I.—LIST OF THE IRISH MINES AND MINERALS. 


[The localities where there were mines or trials are printed in italics. The nearest town 
and the names of the Rock-formation are given in the column of Remarks. ] 


eo 
gS 
s 
=] 
u 


) 


° 
CounTiEs. | 65 
26 


Antrim, 


Carlow. 


Donegal. 
Dublin. 


Londonderry. 


Wicklow. 


GOLD. 


LocaLitizs. 


Slieve-an-Orra. 


St. Mullin’ s. 


Carrigacat or Dhurode. 
Kilerohane (Sheep 
Head). 


Knaderlough. 


Ballinascorney and 


Rathfarnham. 


Moyola River. 


Darragh-water or Augh- 
rim River. 


Ballymanus. 


REMARKS. 


Glendun— Diluvium.—Said to have been 
found about thirty years agoin Glen- 
dun burn. 


St. Mullin’s—Diluvium.—The exact 
place where the gold was found is 
unknown, but it is supposed to have 
been in the streams of Slievebaun 
(White Mountains). 


Crookhaven— Yellow Sandstone, or De- 
vonian.—In the gossan of the copper 
loads. Near Ballydehob, in this pro- 
montory, is the copper mine of 
Skeaghanore (whitethorn bush of the 
gold). No gold, however, has been 
recorded from this mine. 


Ballyshannon — Cambrian (?).— See 
County Histories. 


Dublin—Dilwium.—In the gravel of 
the River Dodder. 


Draperstown—Diluviwm.—This is a lo- 
cality mentioned by Gerrard Boate, 
A.D. 1652; but no gold has been 
found in recent years. The nature 
of the rocks and minerals in the 
county where this river rises would 
suggest the possibility of there being 
stream-gold in the valley. 


Woodenbridge—Diluvium.—In the gra- 
vel of this valley and the tributary 
valleys; namely, Goldmine valley and 
its tributaries, Kilacloran stream, 
Coolballintaggart stream, valley of 
the Ow and its tributaries, and the 
Kilmacreddan burn. 


Aughrim—WMetamorphic Ordovician.— 
Particles of gold in a quartz vein, 
discovered by Gerrard A. Kinahan. 


Scientific Proceedings, Royal Dublin Society. 


| REMARKS. 


206 
SEy 
Countizs. | 58 Locauitizs. 
Aan 
S) 
Wicklow. | 35 | Castlemacadam. 
09 85 | Ballymurtagh. 
” 35 | Tigroney. 
99 85 | Cronebane. 
99 35 | Connary. 
99 835 | Kilmacoo. 
99 40 | Ballycoog. 
59 40 | Ballinasilloge. 
” 39 | IMoneytiegne. 
” 8 | Greystones. 
ry) 8 | Bray Head. 


‘Wicklow and 
Kildare. 


Liffey and Slaney 
Valleys. 


| Ovoca—Diluvium.—In the gravel of 
the Ovoca river; south of the Rail- 
way Station. 


Ovoca—Ordovician.—-In the gossan and 
gossan lodes of the mines on the 
Ovoca mineral channel gold has been 
detected ; also in places in the regular 
ores of the lodes. The gossan lode 
of East Cronebane (Magpie Mine) 
seems to haye been richest. In 
places, the Kilmacooite, or ‘‘ Blue- 
stone,’’ of the Magpie and Kilmacoo 
are also auriferous. 


Greystones — Glacial drift.—In the 
washings of the sea-cliffs to the 
northward of the village; associated 
with black magnetic sand. 


Bray—Cambrian.—Particles in a small 
quartz vein, discovered by Francis 
Codd. 


Diluvium.—According to: the Annals, 
gold ‘‘placers’’ were worked in the val- 
ley of the Liffey, and probably also in 
the valleys of the head waters of the 
Slaney. The river systems of the 
Slaney and Liffey have changed from 
what they were originally ; asat one 
time the Liffey occupied the valley 
from Ballymore-Kustace to Baltin- 
glass, and joined there into the Slaney 
valley. This change cannot have been 
at a very distant period. The Slaney 
also at one time seems not to have 
gone through the Granyte range ; but 
at Tulla to have gone south-west- 
ward. This, however, was a much 
earlier change, as the river was* 

. banked into its present course by the 
“‘Ksker sea gravel.’? The ancient 
workings are supposed to have been 
somewhere near Ballymore-Eustace. 
Places that? gold might be looked 
for are: in Glenimale and the other 
head valleys of the Slaney; and in 
the ancient river course of the Liffey 
between lBallymore-Eustace and 
Baltimore. 


KinaHan—On Irish Metal Mining. 207 


TIN. 


CounrTIEs. Loca.irttts. REMARKS. 


No. of 
Sheet 


vo 
q 
3 
is} 
Ko) 
iI 
ie) 


Dublin. 23 | Dalkey. Kingstown—Granyte.—With lead and 
zinc. The mine worked for the 
lead. The only place in Ireland 
where tin is at present known to have 
occurred as an ore in a lode. It is 
reported to have been found at Kil- 
crohane (Sheep Head), Co. Cork, but 
the find has not been authenticated. 


Kerry, Lough Leane (?) Killarney—Devonian ?— Although tin 
has not been found here in recent 
years, Nennius, writmg in the 
ninth century, Historia Britonum, 
mentions tin, lead, iron, and copper, 
as occurring in this vicinity. All of 
these except the tin have since been 
found and profitably worked. Smith, 
in his Natural History of Kerry, 
states he found an ore containing tin 
near the lake, but does not give par- 
ticulars. 


Wicklow. 40 | Goldmine River. Woodenbridge — Diluviwn. — With 
stream-gold and magnetic sand. In 
this locality there is possibly a lode 
containing the tin, but it has still to 
be discovered. [See ‘‘On the Pos- 
sibility of Gold being found in the 
Co. Wicklow,’’? Sci. Proc. Royal 
Dublin Society, February, 1883. ] 


NATIVE SILVER. 


[In the following lodes and localities, native silver has been found, but only in small 
quantities. Silver-lead (argentiferous galenite) occurs in numerous other places, and 
in a few places silver-copper (argentiferous chalcopyrite) | :— 


o 
wo 
CouNnrTIEs. 6a 3 Locanitizs. REMARKS. \ 
ZERO 
S) 
Clare. 35 | Milltown. Tulla— Carboniferous. — Ancient lead 


mine, in which were found stone and 
wood implements. 
: Norz.—A ‘‘silver mine’’ is recorded 
in James I.’s time ‘‘adjacent to the 
O’ Loughlin Castle,’’ in the barony 
of Burren. The ore, however, was | 
probably silver-lead. . 


99 


208 


CounrTIES. | 
Cork. 


Dublin. 


Galway. 


Kilkenny. 


Leitrim. 


Limerick. 
Sligo. 


Tipperary. 


Scientific Proceedings, Royal Dublin Society. 


Ordnan’e 
Sheet. 


Ge 
fo} 
° 

a 


147 


26 


122 


107 
and 
117 


30 


30 


32 


11 


20 


22 


26 
26 


35 
35 


| 35 


LocatitiEs. 


Boulysallagh. 


Ballycorus. 


Caherglassen. 


Carhoon (?) 


Lissooleen. 


Clogher. 


Bailygaltion. 


Twigspark. 


Ballysteen or Bally- 
canauna. 


A bbeystown. 


Garrane. 


Silvermines. 
Shallee. 


Cronebane. 
Connary. 
Kilmacoo. 


REMARKS. 


Crookhaven — Devonian. — Associated 
with lead and copper ores. 


Goldenball—Ganyte.— With lead ore. 
A large piece was accidentally put 
into the smelting-pot with the lead 
ore, and the silver ran into the brick- 
work of the furnace (ane). 


Gort—Carboniferous.—With lead ore. 
Pieces said to have been of a fair 
size. 


Tynagh— Carboniferous.—A very an- 
cient mine, possibly one of the sil- 
ver mines mentioned in the early 
Annals. 


Tralee — Carboniferous. — Threads and 
particles of silver in the lead ore. 


Castleisland— Carboniferous. — Threads 
of silver in the lead ore. 


Inistioge —Carboniferous.—A very an- 
cient mine, supposed to be the Arge- 
tros (Silverwood) of the Annals, 
when silver shields were made, A.M. 
3817. 


Lurganboy — Carboniferous. — In mi- 
nute specks and strings in the lead 
ore. 


Askeaton— Carboniferous. — Thread of 
silver in the lead ore. 


Ballysodare — Carboniferous. — Strings 
and particles in lead ore. 


Toomavara. — Carboniferous. — Adjoin- 
ing the mearing of Kilnafinch there 
is a very ancient mine, supposed to 
be the Rosargid (Silverwood) of the 
Annals. 


Nenagh—Carboniferous.—Very ancient 
mine. In these mines and the newer 
mines to the westward at Shallee, 
native silver associated with lead, and 
in some lodes with copper. 


Ovoca— Ordovician. — Associated with 
the lead ore of the Gossan lodes, and 
with the Kilmacooite. See Lead ore 
List. 


Kinanan—On Trish Metal Mining. — . 209° 


LEAD AND ZINC. 


[Except in a few localities the ores of zinc are accompanied by those of lead. In many. 
places are found more or less grouped together the sulphides of lead (galenite), zinc 
(dlende or sphalerite), and iron (pyrite or sulphur ore), and more seldom the sulphides | 
of copper (chalcopyrite), arsenic (arsenopyrite or mispickel), and antimony (stzbnite), 
with the sulphate of baryta (barite). ‘Thelead ore is often argentiferous, and.in a 
few places the copper ore. In some places are found the carbonates of lead (cerussite), 
zine (calamine), and copper (malachite), also the silicate of zinc (Smithsonite). | 


Counrizs. one Locatiriss. REMARKS. 
4 52 
Armagh. | 25 | Carrickgallogly. aoa 
i 5 | 25 |) sdvonaneeanen: Belleek— Ordovician.—Lead. 
ke 28 | Dorsay. Crossmaglen— Ordovician.—Principally 
a 31 | Tullyard. lead. 
“a | 19 | Clay. Keady—Ordovician.—Principally lead. 
aA | 19 | Doohat, or Crossreagh. At Clay there is also manganese. At 
ys 19 | Drummeland, or » Carryhugh Glen there are two silver- 
Derrynoose. lead lodes, called the Red and Blue 
i 19 | Carryhugh. lodes ; the first being i in a ferriferous 
9 19 | Darkley. stuff, and the other isa bluish flucan. 
. 19 | Tullyhawood. 
o 15 | Tamlaght. Middletown— Ordovician.—Lead. 
9p 22 | Drumbanagher, or Newry—Ordovician.(?)—Lead. 
Church Glen. 
56 25 | Ballintemple. Newtownhamilton— Ordovician.— Lead : 
se Finiskin. Cullyhanna—07dovician.—Lead. 
56 22 | Kilmonaghan. Goragh Wood (Gerrard’s Pass)—Ordovi- 
cian.—Lead. 
18(?)| Ballymore. Poyntzpass— Ordovician. (?)—An ancient | 
mine; its exact site being now un- 
determined.—(Grifith.) 
Cavan. 22 | Cornanurney. Cootehill—Ordovician.—Lead and‘ sil- 
“5 22 | Cloghstrukagh. ver-lead. 
22 | Drumfaldra. f 
51 29 | Shercock. ; South east of . . —Ordovician.—Lead.. 
‘7 10 | Ortnacullagh (Bally- Belturbet— Carboniferous.—Silver-léad. 
connell). 
Clare 6 | Cappagh. Bally vaughan— Carboniferous.—At 
Be 6 | Moneen. Cappagh there are silver-lead, copper, 
. 6 | Ailwee. and manganese. At Sheshodonnell 
99 6 | Mogoahy. only carbonate of zinc, which octurs 
53 6 | Glencrawne. in botryoidal masses. At Lisnauroum 
99 6 | Sheshodonnell. copper is associated with the lead: 
is 8 | Lough Aleenaun. while in the other localities lead only 
ah 9 | Lisnauroum. is recorded.—See note, Native silver, 
BA 8 | Doolin Castle. Co. Clare. 
! 
SCIEN. PROC. R.D.S.—VOL. V. PT. IV. Q 


210° 


CounrTIEs. 


Clare. 


Scientific Proceedings, Royal Dublin Society. 


26 
34 
35 
35 


51 
43 


Loca.irTIzs. 


Glendree. 
Carrownakilly. 
Rathlaheen West. 
Newmarket. 


Ballyhicky. 
Castletown. 


| Moyreish. 


Monanoe, or 
Kilbreckan. 


Ballyvergin. 
Knockaphreaghaun. 
Milltown. 
Carrahin. 


Crumlin. 
Doolin. 
Ballykelly. 


Rathlaheen South. 
Knocksnaghta. 


Ballyhurly. 
Cahir. 
Ballynagleragh. 


Kilkinnikin. 
Killaconenagh. 


Gortacloona. 
Killoveenoge. 
Rooska. 
Lissaremigq. 


Ballycummisk. 
Kilkilleen. 
Leheratanvalley. 


REMARKS. 


Feakle—Ordovician.—Lead. 


Newmarket-on-Fergus— Carboniferous. 
—At the first the ore was silver-lead, 
while at the second it was associated 
with sulphur ore. 


Quin— Carboniferous.—Pockets of lead- 
ore occurred at these places; they 
are now worked out. They consisted 
principally of silver-lead. At Mona- 
noe, or Kilbreckan, the peculiar mine- 
ral called Kilbreckanite was found, in 
which lead and antimony were mixed 
in such proportions as those used for 
printers’ type. 


Tulla—Carboniferous.—Silver-lead prin- 
cipally. At Ballyvergin there was 
also copper and sulphur ore. At 
Milltown, avery ancient mine, native 
silver occurred; while at Carrahin 
tumblers only have been found. The 
deposits in general seem to be worked 
out; but near Ballyvergin and Mill- 
town are untried calcspar veins. 


Broadford — Ordovician.—Supposed to 
be worked out—silver-lead princi- 


pally. 


Sixmilebridge—Ordovician.—Lead and 
sulphur ore. Tumblers of lead were 
found at Gallows Hill, close to the 
western continuation of the great 
fault of Silvermines, Co. Tipperary. 
—See list, Co. Tipperary. 


Tomgraney — Ordovician. — Principally 
lead. 


Bearhaven—Carboniferous Slate—Lead. 
In the latter townland traces of lead 
and copper in different places. 


Bantry—Carloniferous Slate.—Silver- 
lead, silver-copper (grey copper ore), 
iron (chalybite), copper, and arsenic. 


Ballydehob— Yellow Sandstone, or Devo- 
nian.—Lead and copper. At Bally- 
cummisk, also barytes.—See Copper 
list. 


CounriEs. | . 


Cork. 


99 


75 & 


106 


107 


103 
108 
107 


Kinauan—On Irish Metal Mining. - 


Locatitigs. 


Coosheen. 


Boulysallagh. 


Kilmoe (Spanish Cove). 


Cooladerreen. 
Rabbit Island. 


Duneen. 


Ringabella. 
Minane. 


Carrigtohill. 
Bundoran. 


Abbey Island. 
Abbey Lands. 
Finner. 
Ballymagrorty. 
Carricknahorna. 
Tonregee. 
Welshtown. 


Carrowmore, or Glen- 
togher. 


Fanad. 


Drumreen. 
Ards. 


Keeldrum. 
Marfagh. 


Drumnacross. 

Fintown, Loughnam- 
breddan. 

Gwebarra River. 


Kilrean. 
Mutllantiboyle. 
Scraig Mountain. 


ait 


REMARKS. 


Skull— Yellow Sandstone, or Devonian.— 
Lead, copper, and iron. 


Crookhayen— Yellow Sandstone, or Devo- 
nian.—Lead and copper. Silver-lead 
and silver at Boulysallagh. 


Leap—Carboniferous Slate—Silver-lead. 


Castletownsend— Yellow Sandstone, or De- 
vonian.—Lead, antimony, and copper. 


Clonakilty— Carboniferous Slate.—Lead, 
barytes, and copper. Worked prin- 
cipally for barytes. 


Nohaval— Carboniferous Slate. aes 
lead and lead. 


Vicinity of .. nin hite Slate.— 
Lead and zinc. 


Vicinity of . . —Carboniferous.—Lead 
and copper traces. 


Ballyshannon—Carboniferous.—At the 
first three, silver-lead, zinc, and cop- 
per; at the others principally lead. 
At Carricknahorna also iron; worked 
in 1883. 


Ballybofey— Metamorphic Ordovician(?) 
—Lead and iron. 


Carndonagh—Cambrian, or Ordovician. 
—Silver-lead, zinc, and sulphur ore. 


Glinsk—Cambrian. (?) —Lead and cop- 
per traces. 


Carrigart— Cambrian. (?)—Lead. 


Dunfanaghy— Cambrian, or Ordovician. 
—Lead, copper, and sulphur ore. Ex- 
cept at Ards, the lodes were worked 
out by the Mining Co. of Ireland. 


Glenties—Ordovician.—Lead, zinc, and 

- sulphur ore; but principally lead. 
In Scraig Mountain traces of lead 
and copper. 


Q2 


242° Scientific Proceedings, Royal Dublin Society. 
see 
Countizs. | 553 Locatitizs. REMARKS. 
Z§u 
Donegal. 64 | Iniskeel. Naran— Ordovician.(t Voeee and cop- 
per. 
i 89 | Malindbeg. Killybegs— Ordovician. (? J Sika tent 
and manganese. 
A 44 | Derryveagh (Gartan). Church Hill—Cambrian.(?)—Lead. 
iy 53 | Knockybrin. Letterkenny—Ordovician.—Lead at the 
Re 53 | Woodyuarter. mearing of Knockybrin and Wood- 
5 45 | Lough Gannon. quarter. Further northward tum- 
blers of lead in Lough Gannon. 
Notr.—The ages of the Metamorphic 
Rocks in north and west Donegal are 
undetermined; they are probably Or- 
dovicians and Cambrians. 
Down, 53 | Glasdrumman. Annalong—Ordovician.—Lead and cop- 
per. 
ial hie 45 | Ardtole. Ardglass—Ordovician.—Lead. At Gun’s 
uauiy 89 | Gun’s Island. Island, also, copper and ‘barytes. 
7 48 | Fofanny. Bryansford—Ordovician.—Lead. 
63 55 | Leitrim. Kilkeel— Ordovician, and Granyte.— 
AC 52 | Mourne Mountains. Lead with, in places, copper. 
&e. 
s 44 | Ballydargan. Killough — Ordovician. — Lead, wih 
Hp 45 | Killough. barytes at Rathmullen. 
59 45 | Rathmullan. 
op 45 | Rathdrum. 
is 43 | Moneylane. Dundrum — Ordovician.— Principally 
ap 43 | Wateresk. lead. 
“A 81 | Corporation. Killyleagh—Ordovician.—Lead. 
56 31 | Tullyralty. Strangford—Ordovician.—Lead and cop- 
SC 81 | Castleward. per; also zinc at Castleward. 
$5 21 | Dromore. Vicinity of . . —Ordovician.—Lead and 
manganese. 
ie 6 | Whitespots (Conlig). Newtownards—Ordovician.—Lead. A | 
peculiar lode. A highly metallifer- 
ous whinstone dyke, so rich with lead 
that it could be profitably worked as 
an ore. 
1 | Ballyleidy. 


Crawford’s burn--Ordovician.—l ead. 


S54 
CouNTIES. E 23 
Dublin. 
18 
_ 17 
a 14 
: 19 
33 * 
3? a 
be) 
a 18 & 
17 
a 18 
Ns 18 
35 26 
aA 26 
ci 26 
a 16 
s 23 
rf 23 
Fermanagh. 


Galway. 117 
Sd 107 

& 

117 

5 117 

a 118 

i 103 

% 103 


Kinanan—On Trish Metal Mining. 218 


Lova.itizs. 


14 &| Ashtown. 


Castleknock. 
Cloghran. 
Clontarf. 
Killester. 
Crumlin. 


Dolphin’s Barn. 


Kellystown. 
Kilmainham. 
Pheenix Park. 


Baliycorus. 


Rathmiehael. 
Shankhwll. 
Howth. 


Dalkey. 


Mount Mapas. 


Magheramenagh. 


Crannagh. 
Carhoon. 
Quarry Hill. 


Ballymaquiff. 
Muggaunagh. 


| Parkatleva. 


REMARKS. 


Dublin—Carboniferous Limestone (Calp 
division).—Lead was the principal 
ore, except at Dolphin’s barn, where 
there was also zinc. The lodes at 
the places printed in italics are sup- 
posed to be worked out. 


Golden Ball—Granyte.—Here are situ- | 
ated the lead-reducing works of the |} 
Mining Company of Ireland : the: lead 
lode is said to be worked out. Native | 
silver found here.—See Native silver. 


Golden Ball—Granyte.—Lead : said to > 
be worked ‘out. 


Vicinity of . . —Cambrian.—Lead: 
worked out. ; 


Kingstown — Granyte.—Worked out. | 
Zinc and tin associated with lead | 
ore. In no other place in Ireland, in 
modern times, has tin, as an -ore, 
been found in a vein.—/See Tin list. 


Killiney Hill— Ordovician, —Copper and 
lead: worked out. 


Belleek— Carboniferous.—Lead in =a 
quantities : worked about 1872. 


Tynagh — Carboniferous. — Principally | 
lead. For the works at Carheor: see |. 
Native silver hist. 


Ardrahan—Carboniferous.— The paying |: 
portions of the known veins are work- |: 
ed out. Lead oepciated with copper 
at Muggaunagh. 


214 


CounrTirs. 


Galway. 


th) 


9 


Scientific Proceedings, Royal Dublin Society. 


108 


LocatiriEs. 


Caherglassaun. 


Killeely. 
Rinvile West. 


Cappanaveragh (Lena- 


oy). 
Spiddal West. 
Kilroe West. 
Inverin and Minna. 
Tully. 


Rossaveel. 

Derroogh South. 

Booroughaun. 

Keeraunbeg. 

Carrowroe south. 

Clynagh (Crumpaun). 

Lettermuckoo (Carra- 
finla). 

Derrynea (Loughaun- 
weeny). 


Leenaun (Benwee). 
Griggins. 


Derrylea. 
Bamanoran. 
Lettershask Lough. 


Roundstone. 


Claremount. 
Tonweeroe. 
Ardvarne. 
Illaun-na-creeva, 
Moyvoon East. 
Lemonjield. 
Eighterard. 
Cregg. 
Portacarron. 


REMARKS. 


Gort—Carboniferous.—A rich lode, sil- 
ver, and silver-lead. A large mass 
of the latter was exhibited at the 
Dublin Exhibition, 1851. Unfortu- 
nately, on account of the cavernous 
nature of the limestone, the tide’s 
ebb and flow affect the water of the 
mine, and prevent the deep ore from 
being followed. 


Kilcolgan—Carboniferous.—Lead. 


Oranmore— Carboniferous.x— Lead and 
zine. 


Galway—Granyte.—Lead. 


Spiddal—G@ranyte.—Lead, copper, and 
sulphur ore. At Minna there is a 
fair show of copper. 


Costelloe, or Cashla Bay.—Granyte.— 
Principally lead; copper at Derry- 
nea and Rossaveel. In the Carrow- 
roe promontory, bearing about N.N.E. 
and 8.S.W., is a large reef of quartz 
that, in places, has a slight mineral 
staining. 


Leenaun—Si/urian.—Lead and silver- 
lead; also barytes at Griggins. 


Clifden—Metamorphic Cambrian and 
Ordovician.—At Derrylea there was 
a large excavation in search of gold, 
not a particle of which was found. 


Vicinity of .. —Granyte.—Lead. 


Oughterard — Carboniferous.—Lead : 
principally. 


CouNTIES. 


Galway. 


39 


99 
o> 


2? 


Kildare. 


99° 


KinaHan—On Irish Metal Mining. 


LocatirtiEs. 


Barnagorteen. 
Curraghduff North, 

Middle and South. 
Derroura. 
Barratleva. 
Rusheeny. 
Canrawer. 
Cregg. 
Clooshgereen. 
Glengowla East. 

oP West. 


Corranetlistrum. 


Gortmore (Wormhole). 


Drumsnauy (Doon). 
Carrowgarriff. 


Curraghmore. 


Knockroe. 
Ardfert. 
Clogher. 
Annagh East. 
Meanus. 


Ballybrack. 


Ballinglanna. 


East of Cashen River. 


Lixnaw. 


Caher West, or Shana- 


garry. 
Killowen. 
Public Garden. 


Cahernane. 
Ross Island. 


Ballybeggan. 
Ballymullen. 
Lissooleen. 
Oakpark. 


Ardclogh. 
Wheatfield Upper. 


215 
REMARKS. 


Oughterard— Metamorphic Cambrian and 
Ordovician, with intrudes of Granyte, 
&c.—Where the rock is limestone or 
granyte the ore is principally lead; 
but elsewhere lead, copper, zinc, ba- 
rytes, and sulphur ore occur more 
or less together. At Glengowla East 
the gangue in part was crystalline 
green fluorspar. 


Moycullen—Carboniferous.—Principally 
lead. The Wormhole mine is along- 
side Lough Corrib, and it is difficult 
to keep the water down, as there ‘is 
leakage from the lake. 


Maum Bridge—Metamorphosed Ordovi- 
cian.—Lead, copper, manganese, and 
1ron. ; 


Headford—Carboniferous.—Lead and 
sulphur ore. 


Monivea—Carboniferous.—Lead. 
Vicinity of . . —Carboniferous.—Lead. 


Castleisland — Carboniferous. — Silver, 
silver-lead, and copper. 


Castlemaine — Carboniferous. — Silver- 
lead; with zinc at Annagh, and a 
little copper at Meanus, 


Causeway— Carboniferous.—Lead; with 
a little copper on the coast to the . 
east of Cashen River. 


Kenmare — Carboniferous.—Lead. At 
Shanagarry, a sub-division of Caher 
West, silver-lead and copper are asso- 
ciated. 


Killarney— Carboni ferous.— Silver-lead 
at Cahernane. Lead, zinc, and cop- 
per at Ross Islend. 


Tralee — Ca ‘bonij erous.— At Oukpark 
only lead is recorded; at the others 
copper was associated with silver-lead. 
Native silver at Lissooleen. 


Celbridge—Carboniferous.—Lead; with 
some zine at Wheatfield. 


916 


Kildare. 


Kilkenny. 


| Leitrim, 


29 


CounrTIES. 


Scientific Proceedings, Royal Dublin Society. 


3 


82 
43 


27 


12 


36 


36 


| 25 | 


Loca.itizs. 


REMARKS. 


Freagh. 


Ballygation. 
Dunkitt. 


Knockadrina (Flood 
Hall). 


Monasterorts (Blundell 


Mines). 


Slieve Bloom. 


Barrackpark. 


Twigspark. - 


Ballyeanauna, or Bally- 
steen. 

Graiguelough. 

Askeaton. 

Kilcolman. 


Bailydoole. 


Ardgoul South. 
Freagh. 
Boolaglass. 
Ballingarrane. 
Cloghatrida. 
Ballinvirick. 


Mahoonagh. 


Tower Hill. 


Edenderry — Carboniferous. — Lead : 
worked out. 


Inistioge—Carboniferous.—Silver-lead. 
Kilmacow— Carboniferous.—Lead. | 


Knocktopher — Carboniferous. — Silver 
and silver-lead ; a very ancient mine. 
See Native silver lst. 


Edenderry — es — Lead: 
worked out. 


Kinnity—In the Ordovician rocks of 
Slieve Bloom, lead and copper have 
been recorded in several places, but 
whether together or separate is ‘not 
mentioned. 


Lrarganboy — Carboniferous. — Silver- 
lead in dolomitic sand. 


Askeaton—Carboniferous.—Lead ; with 
some zinc and pyrites at Graigue; 
at Ballysteen there was silver-lead 
and silver. The known deposits in 
these places, except Askeaton, worked 
out. 


Pallaskenry — Carboniferous. — Cover 
and silver-lead. 


Rathkeale—Carboniferous.—At Ardgoul 
—discovered when making the rail- 
way—there is a good show of silver- 
lead. Freagh and Boolaglass un- |. 
proved. The other places, where 
there was silver-lead, zinc, copper, 
and pyrites, are worked out. 


Newcastle — Carboniferous. — Lead : 
worked out. 


Pallasgreen— Carboni ferous.—Lead. 


Kinanan—On Trish Metal Wining. 


217 


CountIEs. es Locatirizs. REMARKS. 
a & n 
Limerick. 25 | Oola Hill. Oola—Carboniferous.—Silver-lead, car- 
bonate of lead, copper, and barytes. 
» 25 | Carrigbeg, or Coonagh | Doon—Carboniferous.—Lead. 
Castle. 
Londonderry.| 25 | Scriggan. Dungiven — Carboniferous.— Tumblers 
and fragments of lead (galenite). 
Longford. 14 | Longford. Two miles H.S.E. of ..—Carboniferous. 
—Silver-lead. 
Louth. 23 &| Oldbridge. ~ Drogheda—Ordovician.—Lead and cop- 
24 per. 
se 7 | Crumlin, Dundalk—Ordovician.—Lead. At Fair- 
ae 7 | Fairhill. hill tumblers were found in the trials 
miade. 
-s 16 | Salterstown. Togher— Ordovician.—Lead and cop- 
per. 
Mayo 108} Ballynastockagh, or Pallyhauniss= Centon jeraus atta 
Bellaveel. 
75 | Bolinglana. Newport — Carboniferous.—Silver- lead, 
- 65 | Srahmore. copper, and pyrites. 
55 107 | Tawneycrower(Sheefry).| Westport—Ordovician.—Silver-lead. 
is 121 | Ballymacgibbon. Headford — Carboniferous.—Lead and 
3 121 | Gortbrack. pyrites. 
Meath 33 | Cloghan. Ardcath—Ordovician.—Lead; very an- | 
cient mine.—(Griffith.) 
x9 29 &| Athboy. South of . . —Carboniferous.—Lead. He 
35 i 
Ne 26 | Dollardstown. Slane (Beaupark mine)—Carboniferous. 
—Lead and copper. 
Monaghan. {19 &| Corbrack. Ballyboy — Ordovician. — Principally 
24 lead. . ; 
ia 19 | Cornamucklagh North. 
< 19 5p South. 
ss 19 | Dernaciug. 
14 | Derrylush. 
a 24 | Sra. 
i 8 | Derryleedigan—Jackson. | Bellanode— Carboniferous.—Lead ‘ and 
zinc. 
a 25 | Cornalough. Castléblayney —Ordovictan.—Lead, * or 
5 25 | Cleggan. silver-lead; barytes at the first ‘two. 
i 25 | Carrickagarvan. , The deposits are supposed ue be 
| 25 | Dromore. worked out. 


218 


CounrTizs. 


Monaghan. 


9 
29 


Queen’s Co. 


29 
99 


Roscommon. 


Sligo. 


99 
> YD 


Tipperary, 
39 
99 
9 
99 


Scientific Proceedings, Royal Dublin Society. 


S Bau 
a8 Locatirtizs. 
ZEO 
6 
15 | Annaglogh. 
19 | Annayalla. 
14 | Avalbane. 
14 | Avelreagh. 
14 | Carrickaderry. 
14 | Carrickanure. 
14 | Clareoghill. 
14 | Coolartragh. 
14 | Cornamucklagh North. 
14 | Croaghan. 
14 | Crossmore. 
14 | Glassdrumman East. 
14 | Grig. 
14 | Kilcrow. 
14 | Latnakelly. 
14 | Lemgare. 
15 | Lisdrumgormly. 
14 | Lisglassan. 
14 | Tassan. 
14 | Tonnagh. 
14 | Tullybuck. 
18 | Dysart. 
82 | Coolbaun. 
$2 | Ballickmoyler. 
20 | Abbeystown. 
20 | Lugawarry. 
6 &9| Glencarbury. 
9 | Tormore. — 
Seafield (Knocknarea), 
22 | Garrane. 
19 | Corbally. 
13 | Garrykennedy. 
19 | Laghtea. 


REMARKS. 


Monaghan—Ordovician.—Lead is the 
principal ore at these localities; it 
being associated with zine at Aval- 
reagh, Kilerow, and Coolartragh. 
barytes also occurring at the latter, 
At Lisglassan and Tullybuck it was 
accompanied by antimony ore. At 
most of the places printed in italics 
the paying portions of the veins were 
taken out. 


Maryborough—Carboniferous.—Lead. 


Ballickmoyler—Carboniferous.—Lead. 


Ballysadare—Carboniferous and Cam- 
brian.(?)—Lead. Native silver at 
the first: the old deposits in both 
places worked out. New veins since 
discovered. 


King’s Mountain, Sligo—Carboniferous. 
—Lead, copper, and barytes. The 
deposit at Glencarbury is principally 
barytes. 


Toomavara — Carboniferous. — Locally 
called the ‘‘ Silver mine ;’’ supposed 
to be the Rosargid of the ‘‘ Annals.”’ 
—See Native silver list. 


Portroe — Ordovician.—Lead. Garry- 
kennedy was a very ancient mine, 
stone and wood implements, &c., hav- 
ing been found in the ‘“‘Old Men’s 
Workings.” 


CounrIEs. 


99 


Tyrone. 
99 


Waterford. 


99 


Westmeath. 


Kinawan—On Trish Metal Mining. 


219 


REMARKS. 


74 
18(?) 
18(?) 


24 
25 


39 


40 


29 


Ballygowan. 
Cloonanagh. 

Cooleen. 

Garryard ast and 
West. 


Gorteenadiha, or Gort- 
nadyne. 

Gortshaneroe, or Bally- 
noe. 

Knockanroe. 

Lacka. 

Shallee East and West. 


Aherlow Vale. 


Crockanboy. 


Teebane West. 


Ballydowane. 
Knockmahon. 


Monminane. 


Cruack. 


Mine Head. 


Monatray. 


Camphire. 


Borrisoleigh—Ordovician.—Lead. 


Silvermines, near Nenagh— Carboniferous 
(sandstone and limestone).—These are 
all sub-denominations of the great 
‘(SILVERMINE Serr.’’ In these mines 
have been found silver, silver-lead, 
lead, silver-copper, copper, zinc, and 
pyrites. They were worked in pre- 
historic times, and the attals in the 
old stulls have lain so long that, by 
chemical change, new minerals have 
formed. The fault at Silvermines, 
on which the lodes are situated, can 
be traced eastward to Toomavara, 
and westward to Gallowshill, near 
Sixmilebridge, Co. Clare. 


Tipperary—Carboniferous.—Silver-lead, 
copper, and manganese. 


Gortin—Ordovician.(?)—Lead ; worked 
in 1854. 


Bunmahon — Ordovician.— These are 
portions of ‘‘BunmaHon CopreR 
Mrnzs.’”’ At both places there was 
silver-lead associated with copper; 
while at Knockmahon zine and co- 
balt were also found.—See Copper list. 


Carrick-on-Suir—Ordovician. (?)—Lead. 


Tramore—Ordovician.—An ancient lead 
mune. 


Ardmore— Yellow Sandstone, or Devoe 
nian.—Silver-lead. 


Coast opposite Youghal— Car boniferous(?) 
—Lead. 


Lismore— Carboniferous.— Silver-lead ; 
worked about the year 1825. 


Traces of lead found in different places. 


990 


Wexford. 


? 


99 


+) 


Counties. 


Scientific Proceedings, Royal Dublin Society. 


Ge 
3 
) 

a 


45 
45 


Locatiti£s. 


Clonmines. 
Barrystown. 


Gibberpatrick. 


Killian. 
South Slob, intake. 
Bishopswater. 


Aughathlappa. 
Caim. 
Killoughrum. 
Mangan. 


Douce Mountain. 
Powerscourt. 


Glen of 


Lough Tay. 


| Lough Dan. 


Boleylug, or Moatamoy. 


Shillelagh. 
Carrigroe. 


Brockagh. 
Lugduff. 


17 &| Camaderry. 


23 


REMARKS. 


Carrick-on- Bannow.— Ordovician. —At 
Clonmines there is the debris of very — 
ancient mines, supposed to have been 
worked by the Ostmen. Here in 
Charles I.’s time there was a mint. 
At Barrystown there were workings 
on a lode containing ster and 
zine. 


Duncormick — Carboniferous. — Lead ; 
veins of dolomite sand with strings 
of lead. 


Wexford — Carboniferous.— Lead and 
barytes veins cut in the canal at the 
South Slob. Strings of lead found 
when sinking the well at Bishops- 
water Distillery. 


Enniscorthy — Ordovician. — Lead, or 
silver-lead. At Caim there were also 
some zinc, copper, iron, and sulphur 
ore. The profitable portion of the 
veins are supposed to be worked out. 


Enniskerry—Granyte and Mica-schist. 
—Lead and copper. 


Holly wood—Metamorphic Ordovician. 
Lead. 


Togher, or Roundwood—Granyte—Lead, 
with at Lough Dan copper and zinc. 
At Carrigeenduff, Lough Dan, the 
vein worked out. 


Baltinglass—Granyte, or Micaeschist.— 
Lead. 


Vicinity of . . —Granyte.—Lead. 


Tinahely—Granyte.—Lead. An ancient 
mine. 


GuEenpaLoveH Lrap Mines.—Granyte 
and Mica-schist. — Luganure and 
Glendassan are sub-denominations of 
Brockagh. Lead, silver-lead, zinc, 
iron, a little copper, &c. 


Kinanan—On Irish Metal Mining. 221. 
seas 
CounrTIEs. ge 3 LocaLiti£s. Remarks. 
6" 
Wicklow. 22 | Lugnaquillia (North Rathdrum, GLenmaLurE Minres— 
Prison). Granyte—Extending in places into the 
is 23 | Ballinafunshoge. mica-schist. All are in Glenmalure, 
5 22 &| Ballinagoneen. the valley of the Avonbeg. In many 
23 places with the lead there are zinc and 
3 23 | Ballyboy. copper. At Barayore there is supe- 
23 | Baravore. rior barytes, and at Clonkeen iron 
AG 22 | Camenabologue. and zinc. At the North Prison, Lug- 
. 23 | Clonkeen. naquillia, there is a promising-looking 
4 22 | Clonvalla. lode, but the place is very inaccessi- 
% 23 | Corrasillagh. ble. 
i 23 | Cullentragh Park. 
. 35 | Ballinaclash. 
a 28 | Aghavannagh. Aughrim—Granyte.—Lead and copper. 
35 40 | Ballintemple. Woodenbridge — Metamorphic Ordovi- 
5 40 | Clonwilliam. cian.—Lead. At Clonwilliam only 
strings have been found. 
. 35 | Shroughmore. Ovoca— Metamorphie Ordovician. — 
a 35 | Kilmacoo. These belong to the EastOvoca Mines 
35 | Connary. In all of them the lead is more or less 
As 35 | Cronebane. associated with copper and pyrites. 
Native silver (auriferous) has been 
found in east Cronebane (Magpie), 
Connary, and Kilmacoo; also the 
peculiar mineral called Kilmacooite, 
or ‘‘ Bluestone,’’ which is a mixture, 
of the sulphides of copper, lead, zine, 
iron, antimony, arsenic, and silver, 
with a trace of gold. ; 
Redcross — Metamorphic Ordovician.— 


x 35 | Kilmacrea. 
Zinc and lead. 
| 


eed ae ert 


222° Scientific Proceedings, Royal Dublin Society. 


COPPER. 


[Copper is recorded as having been found native in the mines at East Cronebane and 
Connary in cracks or slight shrinkage fissures in the veins, while the mine water has 
deposited it on the metals in the old working. Native copper, sometimes in geodes, 
was found at Kilduane, Bonmahon, Co. Waterford, and sparingly in some of the lodes 
in 8.W. Cork. Yellow copper ore (chalcopyrite) is often found associated with lead 
in the limestones of Carboniferous age, but usually in too small quantities to be of 
any value. In the sandstones, whether high up or at the base (Lower Carboniferous 
sandstone), the copper usually predominates. In the Devonian rocks it princi- 
pally occurs as the yellow ore (chalcopyrite), and grey ore (tetrahedrite); and on 
the backs (gossan lodes) of some of the lodes, the carbonates (malachite and agurites), 
and oxide (melaconite). Generally it is only associated with sulphur ore or 
mundic (pyrite) ; but sometimes lead (galenite) and barytes (barite) are present; the 
latter in places being so mixed as to deteriorate or ruin the ore. ‘The ores are most 
prevalent in the Metallic Shales, or the upper zone of the Devonians. In the unaltered 
Silurians, Ordovicians, and Cambrians, also in the granyte, the yellow ore, similarly as 
in the Carboniferous, usually occurs associated with the lead ores; but only in 
small quantities; while in the metamorphic rocks it is in larger quantities ; sometimes 
being independent, but more often associated with pyrites, lead, zinc, or barytes. 
Some of the pyrite or sulphur ore at Ovoca was a poor ore of copper containing from 
2 or 3 to 8 or 10 units; and the copper in the ash of such ores, after the sulphur is 
abstracted, is found to be remunerative. 

At Carrigacat and Kilcrohane, Co. Cork, and Ballymurtagh, Co. Wicklow, the copper ore 
(coppery pyrite) is in part auriferous, while most of the old coppery lodes in the great 
Ovoca channel probably contained some gold. At Garryard, Gortnadyne, and Gort- 
shaneroe, Co. Tipperary, and near Bantry, Co. Cork, the copper ores are argenti- 


ferous. | 
see 
CountTIEs. oes LocaLirrEs. REMARKS. 
a 5° 
Armagh. 31 | Tullydonnell. Crossmaglen— Ordovician. 
5 22 | Kilmonaghan(Gerrard’s,| Newry—Ordovician. 


or Tuscan Pass). 


Carlow. 24 &| Carricklead Mountain. Graiguenamanagh—Granyte. (?) 
26 


Cavan. 20 | Farnham Demesne. Cavan—Carboniferous. 
Clare 6 | Cappagh. Bally vaughan — Carboniferous.— In 

. 6 | Glenulla. small quantities with lead. 

iG 9 | Lisnanroum. 

Ae 20 | Corrakyle. Feakle—Ordovician. 

56 20 | Leaghort. 

as 34 | Ballyhickey. Quin—Carboniferous.—In small quan- 
tities with lead and zinc. 

99 26 | Ballyvergin. Tulla—Carboniferous.—With lead and 
pyzites. 


56 ae Shannaknock. Broadford—Ordovician.—With pyrites. 


CounrtIEs. 


Cork. 


29 


’e 


No. of 
Ordnnn 
Sheet. 


140 
140 
140 
149 
140 
140 
140 
140 
140 
140 
181 


140 
140 
140 


Kinanan—On Irish Metal Mining. 223 


Locatities. REMARKS. 
Allihies. BEARHAVEN Mines— Devonian.—Yel- 
Cahermeeleboe. low copper ore; with a large pocket of 
Caminches. the carbonates in the north mine. 
Cloan. The veins both horizontally and in 
Coom. depth seem to have passed out of the 
Kealoge. ‘metallic shales,’’ (upper zone of the 
Devonians) and to have become un- 
profitable. 
Killaconenagh. Bearhaven—Devonian.—With lead. 
Esk Mountain. Glengarifi— Devonian. 
Carravilleen. Bantry— Yellow Sandstone, or Devonian. 
Clashadoo, or Four- —At Derreengreanagh associated with 
mile Water. barytes. At Lissaremig and Rooska 
Lissareniig. grey argentiferous ore, with silver- 
Rooska. lead, arsenic, and iron (chalybite). 
Derreengreanagh. 
Glanalin. 
Gortavallig. 
Hollyhill. 
Killeen, North. Kitcronane Mines (Sheep Head)— 
» South. Yellow Sandstone, or Devonian.—A 
Knockroe. large lode of sulphur-ore, with strings 
Kilcrohane. or thin veins of yellow copper. 


Along the bedding are beds containing 
grey coppes (argentiferous and auri- 
ferous (?)), and on the back of the lodes 
and beds, carbonates and oxides’ of 
copper. Worked by the South Bear- 
haven Co. At Kilcrohane there is a 
thick sulphur-ore (mundic) lode. 


Ballycummisk. Ballydehob— Yellow Sandstone, or De- 
Cappaghglass. vonian.—BALLYDEHOR AND AUDLEY 
Fowlnamuck. Mines. There are different lodes in 
Horse Island. each sett, some with grey ore, others 
Rossbrin. with yellow. Some of the yellow ore 
Ballydehob. lodes are good, others more or less 
Boleagh. deteriorated with barytes. Lead is 
Cooragurteen. sometimes also found in small quan- 
Kilcoe. tities, as at Ballycummisk, and in the 
Skeaghanore. gossan, at Horse Island. Skeagha- 
Derreennalomane. nore is a peculiar name, as if gold 


was once found there. 


Kitkilleen. Ballydehob— Yellow Sandstone, or De- 
Laheratanvally. vonian.—RoaRInG WatTER MINEs. 
Leighcloon. Copper and lead. 


Scientific Proceedings, Royal Dublin Society. 


224 
Cees 
CounriEs. ge 2 LocatLitigs. REMARKS. 

26h 

Cork. 148] Castlepoint. Sxuui Mines— Yellow Sandstone, or De- 

30 149| Castleisland. vonian.—Generally more than one 

i 139 | Coosheen. lode in each sett. Principal ores the 

& yellow and grey! but at Coosheen 

144 there was a back of carbonates and 

5 140| Gortnamona. iron. At Mount Gabriel_there is also 

3 148 | Longisland. barytes. 

of 148 | Skull. 

i 148 | Leamcon. 

us 139 | Mount Gabriel. 

i 148 | Altar. CrooKHAVEN Mines —VYellow Sand- 

ae 147} Ballydivlin. stone, or Devonian.—Y ellow and grey 

6 147| Ballyrisode. ores. In some setts more than one 

5 147| Balteen. lode. At Carricat the gossan was 

ns 147| Carrieat, or Dhurode. auriferous, at Boulysallagh there 

a 147 | Boulysallagh, were silver and lead, and at Spanish 

A 147) Callaros. i Cove silver-lead. At Balteen a quartz 

5 146 | Cloghane (Mizzen Head). lode was worked for gold, although 

ie 147 | Crookhaven. no gold had ever been detected in it. 

‘S 147| Kilbarry. 

aA 152| IMudllavoge (Brow Head). 

a 147 | Kilmore (Spanish Cove). 

50 147 | Lackavaun. 

965 148 | Zoormore. 

3 151| Bawnishall. Skibbereen— Yellow Sandstone, or De- 
vonian. 

Ress 142} Rabbit Island. Castletownsend— Yellow Sandstone, or 
Devonian.—Also lead and antimony. 

5 142 | Aughatubrid. Roscarberry—(GuanpoRE Mines) Yel- 

a 143 | Derry. low Sandstone, or Devonian.—At 

6 142) Drom. Aughatubrid there is a back of iron 

- 142| Keamore. and manganese that extends eastward 

BS 143 | Kilfinnan. to Roury Glen and Roscarberry (see 

ti 148 | Gortagrenane. list, Iron ores). At Little Island there 

a 143 Little Island. is barytes. 

5 144| Duneen. Clonakilty— Yellow Sandstone, or Devo- 
nian.—Also lead and barytes: the 
mine worked principally for the latter. 

A 107 | Derreens. Dunmanway — Devonian, or Yellow 

5 107 | Coom. Sandstone. 

i 107) Inchanadreen. 

We 78 | Knockadoon. Youghal— Devonian, or Yellow Sand- 

9 78 | Capel Island. stone.—At the Fever Hospital there 

of 67 | Fever Hospital. is a strong coppery-looking spa. . 

5p 63 &| Rathpeacan. Cork—Yellow Sandstone, or Devonian. 

-74.. —Yellow ore, with a little carbonate. 

38 | Millstreet. Vicinity of . . —Devonian. (?) 


CounrTiEs. 


Donegal. 


Fermanagh. 


Galway. 


oe) 


No. of 
Ordnan’e 
Sheet. 


106 


91 
79 
90 
90 


90 


Kinanan—On Irish Metal Mining. 225 


Locatitizs. 


Bundoran. 


Abbeyisland. 
Abbeylands. 
Finner. 
Saltpans. 


Serably and Carrygally. 


Clonea. 
Casheleenan. 


Marfagh. 


Fanad. 
Iniskeel. 
Glassdrumman. 


Gun’s Island. 
Mourne Mountains. 


St. John’s Point. 
Tullyratty. 
Seapoint. 
Malahide. 


Lambay. 


Loughshinny. 


Rossbeg, or Castle Cald- 
well. 


Inverrin and Minna. 
Derrynea. 
Rossaveel. 
Maumeen 

Island). 
Teeranea. 


(Gorumna 


SCIEN. PROC., R.D.S., VOL. V. PT. IV. 


REMARKS. 
j 
| 
Vicinity of ..—Carbonifirous.—Alsoleaa. | 


Ballyshannon — Carboniferous. — With 
lead and zine: worked for the lead ore. 


Rathmullen — Ordovician. —Thin vein 
yellow ore; a quartz lode, to the 
northward, coppery. 


South of Letterkenny—Cambrian.(?)— 
A copper-stained quartz lode, with 
N.E. and 8.W. line of coppery spas. 

Carndonagh—Ordovician. (?) 

Kilmacrenan—Ordovician. (?) 

Dunfanaghy—Cambrian.(?)—Also lead, 
pyrites, and iron: worked for the 
lead principally. 

Glinsk—Ordovician.(?)—Also lead. 

Naran—Ordovician.(?)—Also lead. 


Annalong—Ordovician.—Also lead. 


Ardglass—Ordovician.—Also lead and 
barytes. 


Kilkeel—Granyte and Ordovician.—Also 
lead. 


Killough—Ordovician.—Also pyrites. 
Strangford—Ordovician.—Also lead. 
Blackrock—Granyte.—Traces. 
Vicinity of . . —Carboniferous. 
Skerries—Ordovician.—Also iron. 
Rush— Carboniferous. 


Belleek— Carboniferous. (?)—Also iron. 


Norr.—At Magheramenagh, between 
Castle Caldwell and Belleek, copper 
was raised by the late Mr. Johnston 
in the Carboniferous limestone. 


Spiddal—Granyte, or allied rocks. —Ores 
very mixed; lead and pyrites usually 
present : which, in general, are more 
abundant than the copper. 


226 Scientific Proceedings, Royal Dublin Society. 
CountTIEs. 3hi Locatitizs. REMARKS. 
xu) 
S 

Galway. 54 | Bunnagippaun. Oughterard— Metamorphic Cambrians, 
59 54 | Canrower. or Ordovician.— Lead, pyrites, or 
99 54 | Cregegs. pyrrhotite, are generally present; 
99 54 | Clooshgereen. sometimes zinc and barytes. If the 
99 54 | Glengowla West. lode isin limestone, as at Glengowla, | 
ay 89 | Barratleva. the ore is principally lead. In the 
9 89 | Derroura. Curraghduffs there were good bunches 
99 39 | Curraghduf — West, of yellow copper ore. 

Middle, and South. 
a, 39 | Derreenagusfoor. 
39 389 | Curraunbeg. 
99 39 | Shannawagh. 
An 89 | Derroura. 
i 99 40 | Gorteenwalla. 
” 40 | Ballygally. 
9 39 | Drumsnauv. Maum Bridge—Metamorphic Cambrian. 
» 39 | Maumwee. —At Drumsnauy there were also 
lead, manganese, and iron; while 
at Maumwee the ore was princi- 
pally pyrrhotite. 
a 11 | Leenaun (Benwee). Leenaun Hotel—Stlwrian.—Principally 
lead. 
” 49 | Ballyconneely. Roundstone—Metamorphic Ordovician, 
5 50 | Tallaghlummanmore. Granyte, &c. 
39 63 | Murvey. 
39 63 | Dogs Bay. 
4p 63 | Errisbeg, West and 
Kast. 
39 9 | Cleggan Tower. Clifden — Metamorphic Ordovician, or 
‘ 9 | Tullymore. Cambrian.—In the Rinvyle district, 
55 21 | High Island. Dawrosmore (sheets 10 and 23), Cloon- 
39 22 | Cloon (Cleggan Mine). looaun (9 and 10), Cashleen (9), &e., 
as 22 | Boolard. trials have been made in search for 
45 22 | Doon. copper and iron, but not with good 
an 22 | Dooneen. result. This tract lies to the N.W. 
op 35 | Ardbear. of Kylemore Lake. 
39 85 | Fakeeragh. 
39 24 | Kylemore and Gleni- | Recess — Metamorphic Cambrian.(?)— 
nagh. Also sulphur ore. 
96 386 | Barnanoran. 

Kerry. 30 | Clogher. Castleisland—Carboniferous.—With sil- 
99 ver and lead: worked for the lead. 
3 47 | Meanus. Castlemaine— Carboniferous.— With 

lead: worked for the latter. 
36 9&c.| Coast east of Cashen Causeway—Carboniferous.— With lead. 
River. 
3 52 | Dunquin. Vicinity of . . 


CounrtIES. 


Kerry. 


Kildare. 


bed 


Kilkenny. 


King’s Co. 


Limerick. 


2) 


106 


78 & 


106 


11 
11 


KinaHan—On Irish Metal Mining. — 22k 


Loca.irtigs. 


Greenlane. 
Cromwell’s Fort. 
Mucksna. 


Ardtully (Clontoo). 

Caher West (Shanna- 
garry). 

Caher East. 

Gortnacurra. 

Kenmare, west of. 


Muckross. 
Ross Island. 


Garrough. 
Staigue. 


Ballybeggan. 
Ballymullen. 
Lissoleen. 
Finnies Upper. 
Oughquick. 
Clynacartan. 
Garranearagh. 


St. Crohan, or Behag- 
hane. 


Punchersgrange. 
Dunmurray. 
Knocktopher. 
Monasteroris. 


Slieve Bloom. 


Skreeny. 


Gortnaskeagh. 
Poliboy. 
Shanvans. 


Ballydoole. 
Charter School. 


REMARKS. 


Kenmare—Carboniferous and Devonian. 
—With silver-lead at Caher West. 


Killarney—Carboniferous.—Very ancient 
mines. Cobalt and sulphur ore at 
Muckross; lead: and zinc at Ross 
Island: the latter worked princi- 
pally for lead. Mines mentioned by. 
Nennius, a ninth century writer. 


Sneem— Yellow Sandstone, or Devonian. 


Tralee — Carboniferous. — Principally 
lead. At Lissoleen there is native 
silver. 


Cahersiveen— Devonian, or Silurian. 


Westcove—Devonian.(?) 


Newbridge—Ordovician. 
Kildare—Ordovician. 
Vicinity of . . —Carbonifercus. 
Killan, on Grand Canal.—Carboniferous. 


Kinnity— Carboniferous Sandstone, and 
Ordovician. 


Manorhamilton—WMetamorphie Cam- 
brian. (?) 


Lurganboy—Hetamor. ‘phie reeks ; Cam- 
brian.(?) 
Pallaskenry— Carboniferous.—T he mine 


at Ballydoole was woried for lead. 


R2 


228 Scientific Proceedings, Royal Dublin Society. 
BAIT E 
CounTIEs. cae LocaLirizs. REMARKS. 
Abu 
Limerick. 20 | Ballingarrane. Rathkeale—Carboniferous.—Also silver- 
99 20 | Cloghatrida. lead, zinc, and sulphur ore. The 
deposits, which were wrought for the 
lead, worked out. 
i 25 | Oola Hill. Oola—Carboniferous.—Also lead, zine, 
and sulphur ore: the lead in excess. 
Louth. 22 | Clogher. Drogheda—Ordovician.—Also lead at 
i 23 &| Oldbridge, West of. Oldbridge. 
24 
+5 16 | Salterstown. Togher—Ordovician.—Also lead: seems 
to have been principally worked for 
the latter. 
Mayo. 6 | Ballydergmore. Ballycastle—Carboniferous. 
” 5 | Geevraun. 
ss 7 | Doonadoba. Seacoast N.E. of Ballycastle—Car- 
boniferous. 
5 86 | Louisburgh. Vicinity of . . —Silurian.—Also sul- 
phur ore. 
Re 114) Bojin Island. Cleggan — Ordovician. — Also sulphur 
ore. 
Pr 75 | Bolinglana. Molrany, Corraun Mrnzs. — Ordovi- 
5 65 | Srahmore. cian. (?) 
Meath. 26 | Dollardstown. Slane, BeavparK Minzes—Carbonife- 
6 26 | Painstown. rous.—Also a little lead. 
as 32 | Brownstown. Walterstown—Car boniferous.—W orked 
“ 82 | Cusackstown. in 1800: veins said to be worked 
es 382 | Kentstown. out. 
Roscommon. | — _ —— 
Sligo. 6&9} Glencarbury. Sligo (King’s Mountain)—Carboniferous. 
0) 9 | Tormore. —Also lead ; but principally barytes. 
Tipperary. 33 | Gortnahalla. Borrisoleigh (Clodiagh Valley)—Ordovi- 
cian.—An ancient mine. 
as 88 | Lackamore. Newport—Ordovician.—At Lackamore 
60 88 | Zooreenbrien Uppere ancient tools were found in the ‘‘ old 
mens’ ’” workings. 
7 19 | Derry Demesne. Portroe—Ordovician. 


KinaHan—On Irish Metal Mining. 229 


cy) 
Ciel 5 
Countizs. | 523 Locauitrss. 
An 
Tipperary. 17 | Rathnaveoge. 
> 82 | Coolruntha. 
np 26 | Garryard East. 
AG 26 % West. 
‘ 26 | Gorteenadiha. 
of 26 | Gortshaneroe. 
es 26 | Knockanroe. 
9 26 | Shallee East. 
ss 26 » West. 
5 31 &| Ballyhourigan. 
32 
20 74 | Aherlow Vale. 
5 45 | Clonmurragha. 
ee 45 | Gleenough Upper. 
A 45 | Lackenacreena. 
. 45 | Reafadda. 
‘ 45 | Ballycohen, or Holly- 
ford. 
Tyrone. 37 | Sluggan. 
35 44 | Ballintrain. 
a 45 | Crannogue and Knock- 
naclogh. 
x 45 | Glenbeg. 
sn 45 | Aghafad. 
9 45 | Shanmaghry. 
% 45 | Lurganeden. 
Waterford. 25 | Knockane 
55 25 | Woodstown. 
Ss 25 | Ballydowane. 
oD 25 | Ballynagigla. 
a 24 | Ballynarrid. 
30 24 &| Ballynasissala. 
25 
ae 25 | Kilduane. 
0 25 | Kilmurrin. 
a 25 | Knockmahon. 
es 25 Lankardstown. 
55 24 | Templeyvrick. 
99 24 | Seafield. 
99 13 | Carrigroe. 
Ae 5 | Knockatrellane, or Bally- 
macarbery. 
” 32 | Hillelton (Lady’s Cove). 
29 24 | Kilminnin. 


REMARKS. 


Dunkerrin—Carboniferous. 


SILVERMINES, Nenagh—Carboniferous. 
—Principally in the sandstone. At 
the Garryards, Gorteenadiha, and 
Gortshaneroe there was silver-lead ; 
the copper being also argentiferous. 
At Knockanroe and Shallee there was 
also lead, &c.—MSee Lead list. 


Tipperary — Carboniferous.—Also lead 
and manganese. 


Cappawhite—Ordovician.— 


Pomeroy—Silurian, or Devonian (?)— 
Old working at the southern boun- 
dary of Crannogue; spas at the 
northern boundary. Coppery gossan 
at Shanmaghry and Lurganeden:. 
more or less coppery spas in the 
other townlands. This country is as 
yet unexplored. 


Norr.—These Tyrone rocks may in part 
be the representatives of the English 
Lower Devonian. 


Annestown— Ordovician. 


Bonmanon Mines— Ordovician. — Mi- 
ning in operation at an early age, as in 
some of the old working at the Stage 
lode, Knockmahon, rude stone and 
wooden implements were found. In 
this lode there were also silver-lead, 
zine, and cobalt; at Ballydowane 
silver-lead, and at Kilduane native 
copper.—WSee Cobalt list. 


Ballynamult — Silurian (?) or Devo- 
nian (?) 


Stradbally—Ordovician. 


230 Scientific Proceedings, Royal Dublin Society. 


CountrEs. sas Locairizs. 
250 
Waterford. | 17 | Ballykinsella. 
Westmeath. | — — 
Wexford. 46 | St. Tenants. 
as 41 &| Forth Mountain. 
‘| 42 
a 42 | Kerlogue. 
-t | 19 | Caim. 
Wicklow. 8 | Bray Head. 
Seed 12 | Douce Mountain. 
&c. | Powerscourt. 
” 7 
&e. 
Be 12 | Lough Tay. 
3 17 | Lough Dan. 
is 25 | Ashford. 
3p 25 | Ballymacahara. 
ie 22 &| Glenmalure Mines. 
23 
3 28 | Aghavannagh. 
Me 34 | Aughrim, Lower. 
a 39 | Moneyteigue. 
os 38 | Tinnahely. 
5 39 | Ballinagore. 
a 89 | Ballinvalley. 
3p 389 | Ballycoog. 
. 39 | Ballinasilioge. 
| a 40 | Knocknamohill. 
i 135 &| Ballinapark. 
| | 40 | 
| ap | 85 | Killeagh. 
i 06 | 85 | Ballymoneen. 


REMARKS. 


Tramore—Ordovician. 


Traces of copper and lead in places. 
(Lewis.) 


Duncormick—Carboniferous Sandstone. 
Wexford—Cambrian.—Also sulphur ore. 
Wexford— Carboniferous. — Malachite. 

Enniscorthy—Ordovician.—Silver-lead, 


zinc, iron, and sulphur ore: worked 
for the lead. 


Bray—Cambrian. 


Enniskerry — Near the junction of 
Granyte and Mica schist (Ordovician). 
—Lead also. 


Togher, or Roundwood—Junction of 
Granyte and Mica schist.—With lead 
and zinc. 


Ballinalea—Ordovician. 


Rathdrum—Junction of Granyte and 
Mica schist—In the lead mines a little 
copper occurred at Ballinagoneen, 
Camenabologue, and Ballinacarrig, 
Lower.—See Lead List. 


Aughrim— Metamorphie Ordovician (°) 
Ancient mine at Moneyteigue. 


North of . . —Ordovician.—Iron ochre 
and malachite. 


Woodenbridge, Carysrort MutneEs 
Metamorphic Ordovician.—With iron 
and sulphur ore. 


SoutHweEst Ovoca, or KnockNnAmo- 
HILL, Mines—WMetamorphie Ordovi- 
cian.—Old mines worked for iron; the 
copper and sulphur ore worked a little. 
The prospects at Killeagh are bad; 
also those in }the north portion of | 
Ballymoneen. } 


Kinanan—On Irish Metal Mining. 


231 


ee 
CountrEs. 3s 3 Locatitiss. REMARKS. 
Zan 

Wicklow. 35 | Ballymurtagh. West Ovoca, or BALLYMURTAGH, MINES 
af 385 | Ballygahan, Upper. —Metamorphie Ordovician.—The old 
9 35 is Lower. mines were worked for copper, sul- 
BA 35 | Tinnahinch. phur ore and iron. The prospects at 
06 35 | Kilqueeny. Kilcashel and Knockanode not good. 
99 35 | Kilcashe?. At Tinnahineh and Kilqueeny no 

3 85 | Knockanode. trials have as yet been made. 
pe 85 | Tigroney. East Ovoca, or CronERANE, Minrs— 
ra 85 | Cronebane. Metamorphic Ordovician. — Worked 
a 35 | Castlehoward. principally for sulphur ore, copper, 
Bp 35 | Avondale (Meetings). iron, and ochre; at Hast Cronebane 
3 85 | Shroughmore. (Magpie), Connary, and Kilmacoo also 
an 35 | Connary, Upper. forlead. At the latter mines there is 
36 35 | ilmacoo. the peculiar mineral, Kilmacooite.— 

See Lead list. 
50 35 | Kilmacrea. Redcross— Metamorphie Ordovician. 
3 36 | Templelyon. Associated with sulphur and iron ores. 
$3 35 | Ballykean. Some good looking ‘‘tumblers’’ of 
copper picked up at Ballykean. 

ess 30 &| Ballycapple. Wicklow, BaLLtycappLe Minrs—Weta- 
31 morphie Ordovician.—Worked about 
5 31 | Ballard. 150 years ago for iron ore, which is a 


back to copper and sulphur ore. 


SULPHUR AND GOSSANS. 


[Sulphur occurs native, as concretions in thé Carboniferous Limestone, in the counties of 


Galway, Mayo, and Wexford; but the principal Irish ore from which it is obtained 
is the sulphide of iron (pyrite): but in the Co. Galway pyrrhotite, or magnetic 
pyrites, is found, and has also been minel. These ores usually contain some units 
of copper (chalcopyrite) : the more of the latter present, the greater the value of the 
ore; as after the sulphur is obtained copper can be abstracted trom the ash. Some 
of the pyrrhotites are nickeliferous. Some conspicuous gossans and strong chalybeate 
springs will be included in this list; in some cases they may only indicate the 
presence of iron, yet in many cases they come from pyrite veins. The localities 
where the quantity of pyrite is small and valueless are not given. | 


CounTIES. oes Locativizs. REMARKS. 
23a 
Cavan. 4&6) Legnagrove. District of Glen, Native sulphur (?) 
39 5 | Dowra. (Given in Lewis, but not of late years 
verified.) 
Clare. 26 | Ballyvergin. Tulla—Carboniferous.—Sulphur, lead, 
and copper. 
A 36 &| Shannaknock. Broadford—Ordovician.—Coppery sul- 
44 phur. 


232 


CounriEs. 


Cork. 


Donegal. 


Scientific Proceedings, Royal Dublin Society. 


No, of 
Ordnan’e 
Sheet 


107 
& 
108 
67 


146 


20 


15 


36 


62 


28 
45 
34 
34 
28 & 
35 


LocaLirtiEs. 


REMARKS. 


Demesne. 


Fever Hospital. 

Kilcrohane. 

Carrowmore, or Glen- 
togher. 

Marfagh. 


Scraig’s Mountain. 


Carlan. 

Goldrum and Cash- 
eleenan. 

Ballyscanlan (Fern 

Fycorranagh. 


Spa Cottage. 
St. John’s Point. 


Lisnasliggaun. 
Tanvally. 
Finnisbridge. 


Dunmanway—Devonian (?)—Said to be 
mundic, or poor ore. 


Youghal—Devonian (?)—Strong spa. 


Crookhaven — Devonian. — Thick lode 
sulphur ore with copper. 


> Carndonagh—Ordovician, or Cambrian. 


Sulphur, silver-lead, and zinc. 


Dunfanaghy— Cambrian, or Ordovician. 
Sulphur, copper, lead, and iron. The 
lode was principally worked for the 
lead. 


Fintown—Ordovician, or Cambrian.— 
Sulphur, lead, and zinc. 


Carrowkeel—Ordovician.—Very strong, 
large, reddish spas. 


Kilmacrenan—Ordovician (?)—N. 10 W. 
lode, 3 feet wide; im part flucan, and 
in part quartz, with coppery sulphur 
ore; underlying eastward at 75°. Also 
a N. 20K. quartz lode, with coppery 
stains and strong coppery spa. 


Millford—Ordovician.—A nearly N. and 
8. line of strong spas. 


Letterkenny — Cambrian (?) — Strong, 
reddish spas in the glen at the north- 
western boundary of the townland. 


Norr.—In the metamorphic rocks (Ordo- 
vician, or Cambrian) there are numerous 
spa springs; some are solely due to 
the leaching of the iron (carbonate ?) 
out of the rocks; but when in lines 
along a line of break, or dyke, they 
may possibly point to mineral lodes. 


Ballynahinch—Ordovician.—Iron spa. 


Killough — Ordovician.—Sulphur and 
copper. 


Banbridge—Ordovician.—Iron spas. 


Notr.—For sulphur ore in the Co. 
Galway Carboniferous limestone see 
Lead and Copper lists. 


Kinwanan—On Irish Metal Mining. 233 


oS agpce 
CouNrTIES. a8 Locauitiks. REMARKS. 
a 6a 
Galway. 54 | EKighterard. Oughterard—Carboniferous Limestone. 
<3 54 | Carrowmanagh. —Concretions of native sulphur. 
50 04 | Fough. 
5 40 | Ballygally. Oughterard—Wetamorphie Cambrian, or 
3 40 | Gowlaun. Ordovician. — At Derreennagusfore 
i 40 | Gortnashingaun. the ore is magnetic pyrites (pyrrho- 
95 40 | Farravaun. tite). In some of the copper mines 
- 40 | Drumminnakill. in this district there are considerable 
es 40 | Newvillage. quantities of sulphur ore.—See Lead 
‘5 64 | Derryeighter. and Copper lists, and Geological Survey 
a 53 | Leam East. Mem. Ex. Sheets 93, 94, 95, and 105. 
Ae 58 | Letterfore. The mine at Ballygally was one of 
5 39 | Currane. the first opened; it was worked by 
oF 39 | Derreennagusfore. Nimmo. 
a 39 | Derry. 
5 94 | Galway Dock. Galway—Ordovician. 
on 90 | Mawmeen. Gorumna Island — Granyte.—Coppery 
S 90 | Zeeranea. sulphur ore. 
Galway. 27 | Ashtord. Cong—Carboniferous. 
45 40 | Doorus. 35 Ordovician. 
iS 39 | Doughta. Maum Bridge — Metamorphic Cam- 
i 39 | Maumwee. brians (?)—At Maumean, Lackavrea, 
eS 39 | Lackavrea. and Maumwee the ore is coppery 
ss 38 | Maumean. pyrrhotite, in part slightly nickle- 
Bs 38 | Teernakill, South. iferous. 
5 25 | Cur. 
i 25 | Teernakill, North. 
“p 10 &| Dawrosmore. Clifden—Metamorphie Cambrian (°) 
23 
35 9 &| Cloonlooaun. 
10 
45 9 | Cashleen. 
- 21 | High Island. 
- 22 | Boolard. 
. 35 | Drimmeen. 
5 24 | Kylemore. Recess—Metamorphie Cambrian,—The 
Ss 24 | Gleninagh. Ore is pyrrhotite. A little west of 
Recess are gossany ‘‘shode stones.”’ 
Limerick. — — Nore.—For sulphur ores see lists of the 
Co. Limerick Lead and Copper mines. 
Mayo. 86 | Louisburgh. Vicinity of . . —Silurian.—Coppery 


sulphur. 


234 


CounrIEs. 


Mayo. 


bed 


99 


Tipperary. 


Tyrone. 


Wexford. 


Wicklow. 


Scientific Proceedings, Royal Dublin Society. 


121 
121 


25 


LocatLitizs. 


Achill Island. 
Clare Island. 


Curraun Achill (Gubna- 
binnia Bay). 


Bojin Island. 


Ballycurrin. 
Gortbrack. 


Aghafad. 
Shanmaghry. 
Lurganeden. 
Glenbeg. 


Bree. 


BALLYCAPPEL Mrinzs. 


KOLMACREA 98 
East Ovoca ne 
West Ovoca M5 


Soutu-West Ovyoca 
MINEs. 
Carysrort Minzs. 


REMARKS. 


Molrenny (Clew Bay)— Metamorphic 
Ordovician (?)—Coppery sulphur. 


Cleggan — Metamorphic Ordovician.— 
Coppery. 


Headford — Carboniferous. — Sulphur 
and lead. 


Nors.—For sulphur ore in the Mayo 
Lead and Copper Mines, see Lead and 
Copper lists. 


At Lackamore mine, near Newport, and 
in different places in Silvermines, 
there is sulphur ore associated with 
the lead, &c. In the latter (Cloona- 
nagh) there is a great ‘‘ramp’’ of 
poor ore (mundic).—WSee lists Lead and 
Copper. 


Pomeroy—Stlurian.—Coppery gossans; 
none of the lodes proved.—Sce Copper 
list. In the country hereabouts, and 
to the westward in the large tract of 
Silurian rocks of the Lower Devonian 
type, are many good-looking indica- 
tions of minerals. 


Enniscorthy—Ordovician.—Mundie. 

Norre.—The iron ore at Ballybrennan 
(see Iron list) may possibly be the 
back of a sulphur ore lode. 


The principal minerals in these mining 
setts, all of which lie in the mineral 
channel of the Ovoca valley, are 
coppery sulphur ores. Some of the 
best of these, however (in old times), 
were worked solely for the copper in 
them.—See Copper list. 


KryaHan—On Irish Metal Mining. 


235 


BARYTES. 


[Only the localities where the ore is known to be in quantity are given. ] 


CounrTIES. 


Cork. 


Limerick. 


Monaghan. 


99 


bP) 
Sligo. 


Wexford. 


29 


Wicklow. 


Londonderry. 


3 : Locattirizs. 

(e) 

118 | Derreengreanagh. 
118 | Derryginagh. 

& 

119 

140} Ballycummisk. 
139 | Mount Gabriel. 
143 | Little Island. 

39 | Gun’s Island. 
51 &| Dromore. 

54 

45 | Rathmullen. 

54 | Clooshgereen. 

54 | Canrawer. 

54 | Crege. 

25 | Griggins. 

42 | Bunnaconeen. 

25 | Oolahill. 

40 | Cavanreagh. 

25 | Carrickaganran. 
25 | Cornalough. 

14 | Coolartragh. 
6&9} Glencarberry (King’s 

Mountain). 

43 | Killane. 

43 | South Intake. 

23 | Baravore. 


REMARKS. 


Bantry— Yellow Sandstone, or Devonian. 
—With a little copper. 


Ballydehob— Yellow Sandstone, or Devo- 
nian.—The ore in one lode is so mixed 
with copper ore that both are value- 
less. 


Skull— Yellow Sandstone, or Devonian. 
—A little copper. 


Roscarberry— Yellow Sandstone, or De- 
vonian.—Some copper. 


Ardglass—Ordovician.— With lead and 
copper. 


Vicinity of . . — Ordovician.—With 


lead. 
Killough—Ordevician.—With lead. 


Oughterard—Metamorphic Ordovician, 
or Cambrian.—With copper and sul- 
phur ore. Griggins is in the Maum 
Valley. 


Headford— Carboniferous. 


Oola—Carboniferous.—With lead and 
copper. 


Draperstown—Carboniferous.—Veins in 
sandstone. 


Castleblaney — Ordovician. — With 
silver-lead. 


Monaghan—Ordovician.— With silver- 
lead and zinc. 


Sligo—Carboniferous.— With some cop- 
per and lead. 


Wexford—Carboniferous.—With lead. 


GLENMALURE Mrnes, Rathdrum — 
Granyte and Mica schist. — With 
lead and zinc: very pure. 


236 Scientific Proceedings, Royal Dublin Society. 


IRON. 


[The Irish iron ores occur in bedded masses and in veins. In the recent accumulations, 
principally the alluvium and bog, iron occurs very frequently, often associated with 
manganese (Wad) as bog-iron-ore. In the Cainozoic rocks of Antrim and Derry are 
allied ores known in the trade as the ‘‘ Belfast Aluminous Ore,’’ which occur as 
bedded masses in the Eocene (?) Dolerytes. In the rocks of the Carboniferous period are 
clayey chalybites, as nodules and layers in the Calp and Coal Measures, while in the 
purer limestones of the same period, and the older Devonian, Ordovician, and Cambrian 
rocks, are regular veins and bunches of hematite, limonite, and chalybite. Some of 
the iron ores, however, in these older rocks, seem in part to be bedded or to partake of 
the nature of the veins known as Jay in day, that is, they underlie in the bedding of 
the associated rocks. Some, however, seem, and may be, more intimately connected 
with the associated strata, as a portion of a bed or beds may haye been ferriferous, 
thus forming a bedded ‘‘ bunch of ore.”’ 


The localities where ‘‘ bog-iron-ore’’ occur are so numerous, that it would be impossible to 
enumerate them, but when particularly conspicuous they will be referredto. During 
the smelting operation in the 16th and 17th centuries, when the Irish iron industry 
appears to have been at its height, these bog ores seem to have been extensively 
worked to mix with the other ores. At the present time a peaty variety is at times 
extensively exported to England and Scotland, principally from Donegal, to be used 
for the purification of gas and other purposes. In general, it is found as layers in 
the peat, and may be from blackish to a dirty white in colour, but more often it is of 
a pale yellowish green; these, when exposed to the air, rapidly oxidize, changing in 
colour to yellow or reddish yellow. The bog-iron-ore is employed by gas manufac- 
turers to purify the gas from sulphuretted hydrogen. In the process the ore becomes 
charged with sulphur, thereby becoming very valuable for the production of pure 
sulphuric acid. The residue (drown ochre), is also valuable, being sold for the manu- 
facture of paint. 


It appears remarkable, that the older deposits, especially in the alluvium, are of much 
greater magnitude than any that are now accumulating. This possibly may be due 
to the older masses being, in a great measure, the leaching from the surface rocks ; 
which leaching process, being now long since accomplished, the present depositions 
have to depend solely on the iron brovght up in springs from more or less deep- 
seated rocks]. 


Kunanan—On Irish Metal Mining. 230 


BEDDED IRON ORES. 


[These are arranged in groups, beginning with the younger formation, which necessitates 
the counties not being arranged in alphabetical order. ] 


Eocene (?) 


bse 
CotnrIEs. ee Locauirizs. . REMARKS 
AbD 
Antrim. — | Knockbay. Antrim Iron Measures—Limonite.—In 
5 — | Ballylig. lenticular bedded masses in the dole- 
ay — | Broughshane. ryte; apparently on different geologi- 
3 — | Glenravel. cal horizons: the better and richer 
a — | Cargan. beds being higher than the others. 
55 '— | Newtown Crcmmelin. Associated with lithomarge (ferriferous 
a — | Glenariff. clay), bole (a poor clayey iron ore}, 
f: — | Carnlough. alumyte (alum clay), and lignyte—(see 
i — | Glenarm. Alum and Copperas list). The best de- 
9 —— | Killymurrish. veloped beds occur principally in the 
- — | Shanehill. eastern and northern portions of the 
nn — | Larne, west of. county. The iron ores proper con- 
5 — | Island Magee. sist ot the First, or pisolitic ore, and 
a — | Ballypalady. the Second, or alwminos ore ; but in 
aS — | Port Moon. some cases in the underlying litho- 
#6 — | Rathlin Island. marge are lenticular masses of bole of 
* — | Kellygar. a quality equal to the ‘‘ Second ore.’’ 
a — | Swanstown. At Killymurrish, according to the 
a — | Tully. records of a bore-hole, the [ron Ore 
a — | Kinboe. Measure rested on White Limestone, 
cf — | Cullaleen. as at Craig-na-Shoke, Co. London- 
35 — | Pharis. derry. 
Londonderry. | 85 | Craig-na-shoke. Limonite.—Two miles N.N.E. of 
ms 35 | Moydamlaght. Moneyeany there is a bed at the 
3 35 | Bohilbreaga (Dunmur- base of the Eocene dolerytes, asso- 
ray). ciated with lignyte and the basal 
5 Al | Sheve-Gallion-Carn. Chalk (White Limestone) conglome- 
rate. There is a tradition that 
Rennie, about 1600, worked a simi- 
lar ore on Slieve-Gallion-Carn, but 
none of the ore can now be seen. 
COAL MEASURES (Carboniferous). 
Countizs. | 323 Locatirizs. REMARKS. 
Zen 
Carlow. — | Lemystrr anp East | Layers of nodules and thin seam of 
Kilkenny. — MunstTER CoaL- clay-iron stone on different horizons. 
Queen’s Co. | — FIELDS. The most productive beds occur a 
Tipperary. Busy little below the lowest coal (Gale 
Hil, or Cullenagh, coal), and were 
extensively worked in the Queen’s 


County in the 16th and 17th centuries. 
These ores were used at the furnace 
near Mountrath (Coote’s) to mix with 
Bog and Carboniferous ores.—(S¢ee 
County History.) 


Scientific Proceedings, Royal Dublin Society. 


REMARKS. 


288 
te 3 a 
Counties. | 528 Locatirizs. 
a 6" 
Cork. — | West Munster Coat- 
Kerry. — FIELDS. 
Limerick. = 
Clare. — 
Mayo. — | Slievecarna. 
Sligo. — | Connavcut CoaL- 
Roscommon. FIELD. 
Leitrim. 
Fermanagh. 
Tyrone. 46 | Drumglass (Dungannon). 
BS 47 | Annagher. 
# 46 &| Coalisland. 
47 
89 | Annaghone (Tulla- 


hogue). 


Layers and nodules of clay-iron stone : 
principally associated with the lower 
coals—they were worked very ex- 
tensively in the 16th and 17th centu- 
ries in the counties Limerick and 
Clare adjoining the Shannon. Iron 
ore was smelted at Glin, Loghill, &c. ; 
but a portion of the ore seems to 
have been sent up the Shannon, to 
the furnaces on Lough Derg, to be 
mixed with Bog and Ordovician ores. 
—(See County History.) 


The hills northward of Balla.—Clay- 
iron stone associated with the lowest 
coal.—(See County History.) 


This field, although in general called 
after the province’of Connaught, lies 
nearly equally in the province of 
Ulster. ‘The iron-producing measures 
are in the Middle Coal Measures, 
and considerably below the geological 
horizon, in which the more profit- 
able beds are found in Leinster and 
Munster. The iron (clay-iron stone) 
was extensively smelted formerly, 
and apparently at a later date than 
in the southern province—the fires 
having been put out when the wood- 
fuel was exhausted. In the Co. Fer- 
managh, at the foot of the Cuilcagh 
mountains, there were extensive ex- 
cavations, furnaces, and mills; also 
in the Co. Leitrim—the last fire, at 
Drumshambo, having been put out 
in a.p. 1765. In the Co. Roscom- 
mon the three brothers O’ Reilly first 
attempted in Ireland to smelt iron 
with coal: they, in 1788, establish- 
ing the Arigna Iron Works, and 
opened coal pits—the adventure, by 
them and others, being carried on 
till 1808. Since then others have 
tried. Full particulars of the more 
recent works are given hereafter in 
the County History. 


Tyrone CoaL-FIELD.—These are more 
or less detached. In none of them 
has much clay-iron stone been re- 
corded. This possibly may be due 
to the measures—which in Connaught 
and elsewhere have produced most 
ore—being in this country more or less 
covered up by deep drift, and con- 
sequently not explored. 


Kinanan—On Irish Metal Mining. 


239 


CALP (Carboniferous). 


Remarks. 


See 
CountTIzs. sae Locatitizs. 
S 
Antrim. — | BattycastLe Coat- 
FIELD. 
Dublin. 5&8} Baldongan Hill. 
s 8 | Donabate. 
Londonderry.| 41 | Drumard. 
Bp 41-| Mormeal. 
4 41 | Brackaghiislea. 
Mayo. 29 &| Crossmolina. 
38 
i 9 &| Tallagh. 
10 
Tyrone. 29 &| Kildress. 
38 
= — | Drvmaurn Catp AREA. 
Wexford. 49 | Woarway Bay. 


Clay-iron Stone-—Worked in ancient 
times with the coal; also in the 
beginning of the eighteenth century, 
the ore having been smelted at Bally- 
castle by Mr. Boyd.— (See County 
History.) 


Skerries—Poor Clay-iron stone. 


Draperstown — Clay-iron Stone. — 
Worked principally in Drumard, by 
Rennie, about 1600, and ‘‘ smelted at 
the Drumlamph Iron Works.”? At 
the Moyola River, in the south part 
of Drumconready, there are the ruins 
of an old furnace. 


Barony of Erris—Carboniferous (?)— 
The exact position where the iron 
was raised for the use of Sir George 
Shaen’s furnace near the Mullet, and 
Mr. Rutledge’s, on the River Deel, is 
now uncertain; but it would appear 
as if the ore was procured, in part 
at least, from the Calpy limestone 
(clay-iron stone). , Rutledge was the 
last to work, his fires being put 
out for want of fuel.—(See County 
History.) 


Cookstown—Limonite and Hematite.— 
Extensive trials made about 1880 by 
the Barrow Hematite Company; but 
the works were stopped on account 
of the low prices for iron. 


Omagh—Nodularbedsof Clay-iron stone. 
—Here, as near Draperstown and 
Cookstown, there are rocks belonging 
to the Ulster ‘‘ calp type,’’ in which 
the clay-iron stone is of a fair charac- 
ter. . 


Hook Promontory, Fethard—Poor Olay- 
won stone.—The ore is of a quality 
like that near Donabate, Co. Dublin. 
The associated rocks are also some- 
what similar, but they rest on Car- 
boniferous conglomerate (Upper Old 
Red Sandstone) ; in this locality they 
are probably a littoral accumulation. 


240 Scientific Proceedings, Royal Dublin Society. 


IRON ORE IN VEINS. 


[The mode of occurrence of some of the ores in this list is not as true veins; yet at the 
same time they are not in true beds. Like the ores of the Eocene and Coal 
Measures, they are apparently of a secondary formation, a part of a bed or 
beds becoming ferriferous, the ore being found in an irregular ‘‘ bunch’’ or ‘‘ shoot ”’ 
that underlies with the stratification of the associated rocks. This is espe- 
cially the case with some of the ores in the Ordovician rocks which have been de- 
scribed as ‘‘ beds of ore.’? The localities of some of the ancient iron mines are now 
quite unknown, while the exact sites of others are uncertain. In the latter cases 
the places in the neighbourhood of which the mines were probably situated will 
be mentioned. The localities are arranged in counties. | 


CounTIES. Locatirizs. REMARKS. 


No. of 
Ordnan’e 
Sheet 


Cavan. 16 | Claragh. Redhill—Ordovician.—Ochre and limo- 
nite (?) The veins lie with the 
bedding of the rocks: ores worked 
in 1875. 


Clare. 19 &| Glendree. Feakle — Ordovician Limonite (?) — 

27 Worked prior to 1700. The adit of 
the ancient mine is still to be seen; 
but the exact position or nature of 
the lode is unknown. ‘Tradition says 
that the ore was smelted at the pre- 
sent village of Furnace, a few miles 
eastward of Feakle. One mile N.E. 
of Feakle church are old burrows, 
where there is said to have been an 
‘iron mine.’? The exact position 
of the lode is uncertain, without 
explorations. 


43 &| Ballykelly. Broadford—Ordovician. 
44 


— | Knocksnaghta. Sixmilebridge — Ordovician.— Hematite 
and Limonite, with Graphite. 


28, | Ballymalone. Tomgraney — Ordovician. — Limonite. 
&e.| Bealkelly. Worked rather extensively in the 
16th(?) and 17th centuries, princi- 
pally for the furnaces along the shore 
of Lough Derg between Mt. Shannon 
and Woodford, where it was mixed 
with bog-iron-ore raised in that 
country, and ‘‘ore brought up the 
Shannon,”’ probably from the Coal 
Measures, counties Limerick, Kerry, 
and Clare. 


Cork. 128} Bear Island. ~ Bearhaven, or Castletown—Carbonife- 
rous Slate-—A well-marked vein of 
hematite, associated with micaceous 
iron ore. 


Kinanan—On Irish Metal Mining. 241 


CouNTIES. Locatitizs. REMARKS. 


No. of 
Ordnan’e 
Sheet 


Cork. 142) Aghatubrid. Rosscarbery—Yelluw Sandstone, or De- 
Pe 143 | Roury Glen. vonian.— Limonite associated with 
i 143 | Rosscarbery. manganese, the latter being in 
shrinkage fissures in the iron ore. 
The iron ore seems to occur as the 
back of a copper lode. 


at 118 | Coomhola. Glengariff— Carboniferous {Slate (?) or 

(?) Yellow Sandstone (?)—A ‘mine 1s re- 
corded in this locality by Smith, in 
his history of Cork, 1750. Worked 
by the Whites, who had a furnace 
in the vicinity. 


Cork. — | Aghadown. Roaring-water Bay and Tallow Bridge.— 
5 — | Araglin. These localities are also mentioned 
by Smith, the first being worked by 
the Whites, the second by the Earls 
of Cork. According to Smith, 1750, 
iron was smelted by the Whites at 
Coomhola and Aghadown, and by 
Lord Cork at Araglin, ‘‘near the 
eastern extremity of the county ;”’ 
while Gerrard Boate (1652) states the 
iron was smelted at Tallow Bridge. 
A few miles eastward of the latter, at 
Salter’s Bridge, in the Co. Waterford, 
are the remains of old iron works, 
said to have been worked in the 17th 
century.—See Drumslig, Co. Water- 
ford. The sites of the mines near 
Roaring-water Bay and Araglin are 
now unknown, but they were pro- 
bably in the Yellow Sandstone, or 
Devonian, rocks of the vicinities. 


117| Rooska. Bantry—Carboniferous Slate.—Chaly- 
beate (carbonate of iron), with lead and 
copper: worked for the lead. 


Donegal. 68 | Welshtown. Ballybofey— Ordovician. —With lead: 
the mine worked for the latter. 


u 15 | Marfagh. Dunfanaghy—Ordovician (?) or Cam- 
brian (°?)—With lead, copper, and 
sulphur ore: the mine worked, princi- 
pally for the lead. 


9) 36 | Skreen, Lower. Milford—Ordovician(?)—Limonite. In 
a mass of schist caught up in an 
intrude of whinstone. In the vici- 
nity is a quantity of slag, as if 
smelting had formerly taken place. 


SCIEN. PROC., R.D.S.—VOL. V. PT. IV. S 


242 Scientific Proceedings, Royal Dublin Society. 


CounTIEs. Locatirizs. REMARKS. 


No. of 
Ordnan’e 
Sheet. 


Donegal. 53 | Meenreagh. Letterkenny — Cambrian (?) — Impure 
chalybeate ; appears to be more or less 
in bedded masses in the associated 
rocks. 

Notr.—As has been pointed out by 
different recorders, the remains of 
ancient bloomeries and forges, used 
in the smelting of iron prior to the 
woods of the country haying been 
used up, are found in different places 
scattered over the County. 


Down. 35 | Deehommed. Banbridge — Ordovician.— Hematite. | 
This vein has only been discovered 
about ten years. ‘The ore appears to 
be of a good quality; but on account 
of the depression in trade it has not 
been worked. 


AG 28 | Spa Cottage. Ballynahinch— Ordovician. 


2 28 | Slieve Croob. Dromara— Ordovician. (?)—In this tract 
&e. of mountains, Griffith records iron in 
the townlands of Begny, Gransha, 

Leganany, Moneybane, &c. 


an 14 | Carnreagh. Hillsborough—Ordovician. 


Dublin. 9 | Lambay Island. Skerries—IJntrusive Rocks.—Blocks of 
hematite recorded by Du Noyer, as 
occurring a little 8.W. of Raven’s 
Well, near Bishop’s Bay. Supposed 
to be from the back of a copper lode. 


Fermanagh. 9 | Rossbeg (Castle Cald- Belleek — Carboniferous (2) —Limonite. 
well). Supposed to be the back of a copper 
lode. At Magherameragh a little 
copper was raised by the late Mr. 
Johnstone. 


Galway. 39 | Drumsnau (Doon). Maum Bridge— Metamorphic Ordovi- 
cian.—Hematite (?); with manganese, 
copper, and lead : worked for the lead. 


Galway.* 35 | Derreen. Clifden — Ordovicia.— Limonite in | 
limestone. 


* Inthe west of this county iron ore veins are not recorded ; but in olden times ore was 
smelted in places, such as Lough-na-Furnace, Screeb, and in other places on Galway Bay or 
its inlet. In these places, however, it may have been bog-iron ore that was used, mixed with 
imported ore—as the records inform us that iron ore was imported into places along the 
west coast to be smelted, on account of the abundance of timber; the old iron being made 
with wood charcoal. In the south-east of the county there were extensive furnaces and 
mills adjoining Lough Derg, the last in work, that of Woodford, haying its fires put out 
about the year 1750. The iron ores for these furnaces and mills were procured in the 
vicinity (bog-tron ore) near Tomgraney, Co. Clare (/imonite), and from the Lower Shannon, 


Kinanan—On Trish Metal Mining. 243 


o | 
; Sea { 
Countizs. | 552 Locatitigs. Remarks. 
a5 ean Cake 
Kerry.* — — — 
Kilkenny. 28 | Grenan. Thomastown—Ordovician.—Red hema- 


tite (micaceous). 


Leitrim. 35 | Gortinee. Drumsna—Ordovician.—Limonite raised 
here ; probably in the 16th or 17th 
century. When making the rail- 
way from Longford to Sligo three 
bed-like veins of slaty limonite, bear- 
ing nearly N.E. and S.W., heading 
S.E. at 60° were cut. Subsequently 
they were worked, two shafts being 
sunk for a depth of thirty feet about 
the year 1870, by which the ore was 
proved to improve in depth. On the 
depression in the iron trade the works 
ceased (See County History). 


Limerick. 11 | Askeaton. Askeaton—Carboniferous Limestone, 

— | Kilcolman. Silicious Limonite.—The ore at Kil- 
colman was worked about the 17th 
century, and subsequently about the 
years 1870-75. 


99 


Londonderry.| 31 | Carrick Mountain. Dungiven—Ordovician (?) 
BS 29 | Glenrandal. Stranagallwilly—Ordovician.—Mass of 
Ochre. : 


40 &| Tullybrick (Altihaskey). | Draperstown— Ordovician (?) —Red 

45 Hematite. One of Rennie’s mines 
(a.D. 1600) is said to have been in 
this townland, but the site is now un- 
known. 


45 | Beaghbeg. Tonaragh—Ordovician (?)—Red Hema- 
tite (micaceous). 


counties Limerick and Clare (clay-iron stone). ely Dulton, in his Statistics, History 
Co. Galway, 1824, states:—‘‘Iron ore was formerly raised in the neighbourhood of 
Woodford, and after being mixed with that brought up the Shannon from Killaloe 
by a Mr. Crossdale, was smelted near that village, part of the estate of Sir John Burke. 
The works were carried on so extensively, that they devoured all the great oak woods 
with which that country abounded, and were then abandoned. Mr. Berry, I understand, 
at present raises ore on part of Lord Clanricarde’s estate.”’ 

* At the present time there are no records of mines solely worked for iron, but 
along the coast-line are the remains of different furnaces. According to tradition these 
belonged to Petty (ancestor of the Lords Lansdowne), who imported iron ore about the 
year 1600, to smelt it with charcoal, made in the wood which then abounded in the 
country. Nennius, writing in the ninth century (Historia Britonwm) mentions iron as 
being worked in the neighbourhood of Killarney Lakes; but the site of the old mine is now 
unknown. ‘The remains of very ancient bloomeries and furnaces have been found at 
Killarney and Blackstones (See County History). 


82 


244 


CounTIES. 


Londonderry. 


Longford. 


bd 


Louth. 


Mayo. 


29 


Meath. 


Scientific Proceedings, Royal Dublin Society. 


46 


45 & 


46 


22 


75 
2&3 


Queen’s Co. |13 & 
18 


27 


Locatirizs. 


(Unagh) Slieve Gallion 


Carn, 


Tirgan and Carndaisy. 


Slievemoyle. 


Cranny (Glenview). 


Oleenragh. 
Enaghan. 


Clogher Head. 


Carricknahelty. 


Curraun Hill. 


Corratober. 


Dysart. 
Dunamase. 


Ballynakill. 


REMARKS. 


Moneymore—Granyte.—Hematite in a 
four-foot vein of ferriferous quartz : 
worked by Rennie in 1600, and re- 
cently, about 1875. 


Moneymore—Granyte.—Four-foot lode, 
being N.S.S.W., and hading 8.W. 
at 8°; rich fibrous hematite (kidney 
ore), and ved ochre: worked by 
Rennie, and recently. 


Moneymore—Wetamorphie Ordovician. 
—Hematite and barytes: worked a 
little in 1875. A narrow, nearly ver- 
tical vein, with a north-westerly 
course. 


Desertmartin—Metamorphie Ordovician. 
—Hematite and barytes. A narrow, 
neatly vertical, lode, with a north- 
westerly course: worked a little in 
1875. 


Arvagh — Ordovician.—These bed-like 
veins of limonite are similar to those 
at Gortinee, Co. Leitrim; but the ore 
at Cleenragh is of a better quality, 
while that at Enaghan is not as good. 
Worked in the 16th or 17th century, 
and rather extensively, by Dr. Ritchie 
of Belfast, between 1860-70. 


Clogher— Ordovician.—Limonite. 
Molrany—Ordovician.—Limonite. 


About two miles to the south-east of 
Kingscourt are numerous tumblers 
and fragments of hematite. Source 
not known ; possibly near at hand. 


Maryborough— Carboniferous Limestone. 
—Limonite: worked extensively in 
the 16th and 17th centuries, the ore 
having been brought to be smelted to 
Coote’s furnace, at Mountrath. 


Riverstown—Carboniferous.— Hematite 
veins in the bedding lines. An ancient 
furnace clos: to the mineral veins. 


Kinanan—On Trish Metal Mining. 245 


REMARKs. 


Ballysadare.—There are old iron mines 
recorded at Ballintogher. At the 
base of the Ox Mountains were very 
extensive workings; while furnaces 
and mills were situated at Screevena- 
muck; the fire having been put out 
in 1768 for the want of wood-fuel 
(See County History). 


Cappaghwhite— Ordovician. 


In the valley of the Clodiagh, Borriso- 
leigh — Ordovician. —Limonite. A 
very old mine; when and by whom 
worked is not known. The iron ore 
seems to be the back of a copper or 
sulphur ore lode. Tradition says 
there was a second mine to the N.E., 
near Roscrea, but the site seems to 
be now unknown. 


Cookstown— Carboniferous.—Hematite, 
limonite, and ochre, with manganese. 
Worked in 1600 by Rennie, and sub- 
sequently between 1865 and ’75. 


Pomeroy—Wetamorphie Cambrian (?)— 
This occurs in a mass, and appears 
to be an intrude of whinstone highly 
impregnated with magnetite. It has 
been worked as an iron ore, but not 


Pomeroy—Granyte.—An impure chaly- 
beate in an irregular vein. 


Carrick-on-Suir — Ordovician. —Hema- 
tite (micaceous-iron-ore). 


Dungarvan—Devonian, or Yellow Sand- 
stone. — Hematite discovered and 
worked by Walter Raleigh about, or 
a little before, 1600. Subsequently 
worked between 1850 and 1860. 


Ardmore—Devonian, or Yeliow Sand- 


CouNTIES. nae Locatiries. 
Azan 

Sligo. 21 | Ballintogher. 
Tipperary. 45 | Scotchman’s Coom. 

Ap 83 | Gortnahulla. 
Tyrone. 29 | Lissan. 

56) 837 | Bardahessiagh. 

succes-fully. 

” 37 | Limehill. 
Waterford. 7 | Killerquile. 

9 85 | Dromslig. 

08 35 | Grallagh. 

on 39 | Mine Head. 

40 | Ardmore. 


stone.—Limonite. Probatily worked 
in the 17th century 


246 


CouNTIES. 


Scientific Proceedings, Royal Dublin Society. 


Wexford. 


Wicklow. 


tr) 


99 


38 


29 & 


40 


LocaLirtigs. 


Ballybrennan. 


Ballynastragh. 


Courtown Harbour. 


Ballymoney. 


Cloghleagh. 
Knockatillian. 


Aughowle Upper. 


Tinnahely. 


Mucklagh. 


Moneyteigue. 
Ballycoog. 
Ballynasilloge. 


Mongaun. 


REMARKS. 


Enniscorthy—Ordovieian.—The work- 


ings here appear to have been ancient, 
as nearly all traces of them are 
obliterated. 


Gorey—Ordovician.— These accumula- 


tions are inj part of the nature of 


‘beds. At and in the neighbourhood 


of Ballynastragh portions of a bed or 
beds of purple slate are highly ferri- 
ferous (limonite). Near Courtown 
the same ore occurs as strings or 
veins in the rocks, while northward 
of Ballymoney Fishery there are 
lenticular beds of poor chalybeate. 


Blessington (Glenasplinkeen) — Meta- 


morphic Ordovician.—Limonite, hema- 
tite, and manganese; worked a little. 


Shillelagh—Metamorphie Ordovician. 


Limonite. Some trial made on the 
vein about 1875. Iron ore is said tot’ 
have been raised in this locality in 
Bacon’s and Chamney’s time (16th{. 
and 17th century); but the sites of 
their works are now unrecorded. — 


North of . . —Metamorphie Ordovician. 


—A ramp of limonite partaking of 
the nature of bog-iron-ore; for the 
most part at the surface, or only under 
a thin drift: in places it is copper- 
stained. No traces [of old or recent 
works in connexion with it are appa- 
rent. 


Rathdrum—A rather extensive ferrife- 


rous conglomerate on Metamorphic 
Ordovician (?). Unsuccessfully open 
casts were made in part of it (1875), 
to try and find its source. 


Woodenbridge, Carysrort Mines— 


Metamorphic Ordovician.—Limonite : 
the backs of copper and sulphur- 
ore lodes. Very ancient working 
appears to have existed here; while 
in recent years some tons of ores 
have been raised at Moneyteigue. 


Arklow — Metamorphic Ordovician. — 


A large ferriferous mass, somewhat 
like that at Mucklagh. No trials 
have been made to seek for its 
source. 


Kinanan—On Irish Metal Mining. 


247 


CounrtIEsS, 


No. of 
Ordnan’e 
Sheet. 


Locatirigs. 


REMARKS. 


H> 
i=) 


35 & 


oo > 
aoe 


35 | 


Knocknamohill. 
Ballinapark. 


Ballymoneen. 


Ballymurtagh. 


Castle Howard. 
Cronebane. 
Connary. 
Kilmacoo. 


Templelyon. 


| Ballycapple. 


Ballard. 


Soutu-west Ovoca, or Knocknamo- 
HILL Mrines—Wetamorphic Ordovi- 
cian.—Limonite : the backs of copper 
or sulphur-ore Jodes; worked in the 
17th century, the ore being sent to 
Chamney’s furnaces at Ballynaclash, 
Shillelagh, &e. 


West Ovoca Mines — Metamorphic 
Ordovician.—Limonite with copper- 
staining on the shrinkage fissures, and 
ochre. The back of the North sulphur 
lode was not worked till recent years, 
and iron is at present being raised : 
of late the ochre has been worked. 


East Ovoca Mines—WMetamorphic Ordo- 
vician.—Limonite and ochre. Worked 
in late years; ochre at present being 
raised and manufactured. The backs 
of copper and sulphur-ore lodes. 


Redcross — Metamorphie Ordovician 
Limonite. 


Wicklow—WMetamorphie Ordovician.— 
Limonite, magnetite, chalybeate, and 
ochre, with manganese: seems to be 
the back of a copper or sulphur-ore 
lode. Here there were extensive 
works in the 17th century, the ore 
being smelted by Chamney in the 
Vale of Clara, at Ballynaclash furnace, 
&c.; the old mines are still called 
the ‘‘ Clash pits.”’ 


MANGANESE. 


[This mineral is very universally distributed, but generally more or less minutely ; it is 


very often associated with bog-iron-ore, or other iron peroxides. 


In many cases it is 


valueless. In this list are only given the localities where it might possibly be worked 
profitably as a bye-product with the associated minerals. | 


CounrmTIEs. oe Locatitizs. REMARKS. 
Zé OG 
Armagh. 19 | Clay. Keady—Ordovician.—With lead; not 
in large quantity. 
Clare. 6 | Cappagh. Bally vaughan — Carboniferous..— Asso- 
ciated with lead. 
s 27 | Glendree. Fcakle—Drift.—(Diallogite). 


248 


CounrTIES. 


Cork. 


99 
99 


Donegal. 


Galway. 


Monaghan. 


Tipperary. 


Wicklow. 


Scientific Proceedings, Royal Dublin Society. 


LocatLitigEs. 


REMARKS. 


Aghatubrid. 
Roury Glen. 
Rosscarbery. 


Malinbeg. 


Drumsnaw (Doon). 


Corduff. 
Aherlow Vale. 
Cloghleagh. 
Knockatillane. 


Ballycapple. 
Ballard. 


Rosscarbery — Yellow Sandstone, or 
Devonian. ‘These mines are on one 
channel. In considerable quantity 
associated with iron and copper. 


Killybegs—Metamorphie Ordovician (?) 
—With silver-lead. 


Maumbridge—Ordovician.—With cop- 
per, lead, and iron. 


Bellatrain— Ordovician. 


Tipperary—Ordovician.—With silver- 
lead and copper. 


Blessington (Glenasplinkeen) — Mica 
Schist.—With iron. 


Wicklow—Ordovician.—With iron and 
copper. 


ANTIMONY. 


[It, in general, occurs as the sulphide (s¢i/nite) associated with lead (galenite). | 


CouNTIES. BE 3 
as n 
Clare. 34 
Cork. 142 
Louth. 1 
Monaghan. 14 
» 14 
» 14 
Tyrone. 12 & 
19 
Wicklow. 85 
” 35 


Locaitres 


Monanoe, or Kilbreckan. 


Rabbit Island. 


Jonesborough. 


Lisglassan. 
Tullybrack. 
Clontibret. 


Munterlong Mountain. 


Cronebane (Magpie). 
Kilmacoo (Conunary). 


REMARKS. 


Quin— Carboniferous. —With silver- 
lead.—See Lead list. 


Castletownsend— Yellow Sandstone, or 
Devonian.—Associated with lead and 
copper. 


Vicinity of . . —Ordovician. 


Monaghan — Ordovician.— With lead. 
At Clontibret the vein of stibnite is 
four inches wide. 


Newtownstewart — Ordovician. — Re- 
corded by Griffith. 


Ovoca —WMetamorphice Ordovician.—In 


the Kilmacooite.—See Lead list. 


Kuwanan—On Irish Metal Mining. 249 


ARSENIC. 


[This mineral is very often present in small quantities associated with sulphur-ore 


(pyrites), and sometimes with lead. 


At Cronebane and Connary, Co. Wicklow 


(sheet 35), it occurs as arsenopyrite, locally called ‘‘ Jack Martin,’’ with the sulphur- 
ore, and in the Kilmacooite (see Lead and Zinc); at Lackamore, Co. Tipperary 
(sheet 38), it occurs as arsennopyrite associated with copper ore; but in some places it 
occurs independently, as on the east shore of Adrigole Bay, Co. Cork (sheet 118), and 
at Gubnabinniaboy, near Molranny, Co. Mayo (sheets 65 and 75). In some of the 
mines of south-west Cork, as at Lissaremig, near Bantry (see Lead List), it occurs in 
considerable quantities. ] 


COBALT. 


[Cobalt in quantity has only been recorded as occurring at Muckross, Co. Kerry, where, 
unfortunately, most of the ore (erythrite, or arsenate of Cobalt) was thrown into the 


lake before its value was discovered.—(Kane.) | 


CouNTIES. 


Donegal. 


Dublin. 


Kerry 


Waterford. 


LocaLitizs. 


No. of 
Ordnan’e 
Sheet. 


35 | Barnesbeg. 


15 | Sutton. 


44 | Muckross. 


25 | Knockmahon. 


REMARKS. 


N. of Kilmacrennan.—Traces in pyr- 
rhotite crystal. (Scott.) 


Howth—Carboniferous.—With manga- 
nese. Discovered by Dr. Stokes. 


Killarney — Carboniferous.—Associated 
with copper and pyrites. The major 
portion of the cobalt ore was thrown 
into the lake before its nature was 
discovered by IZ. Raspe in 1794. 


Bunmahon — Ordovician. — Associated 
with copper, silver-lead, and zinc. 
Discovered by J. H. Holdsworth. 


290 


Scientific Proceedings, Royal Dublin Society. 


GRAPHITE (Plumbago). 


[Graphite has been very little utilized, although in some places it seems to be in sufficient 
quantity to have been worked as a bye-product with the associated minerals. | 


wai 
Countizs. | 522 Locauitrss. REMARKS. 
Z2g2 
Clare. 43 | Knocksnaghta. Sixmilebridge —Ordovician.—In a vein 
with iron. 
Donegal. 26 | Sheephaven, near Ards Dunfanaghy and Conyoy.-—Found as 
House. rolled pieces in Gravel. 
= 69 | Burndale. 
Kilkenny. — | Castlecomer Coal-field. Carboniferous.—Fomerly associated with | 
the ‘‘ old Three-Foot Coal.”’ 
Mayo. 65 | Toorreyagh. Achill Island — Ordovician.—Graphitic | 
micalyte to the east of Doonaglass | 
Point. (ditchell.) 
Tipperary. 40 | Gleninchinaveigh. Upperchurch—Ordovician.—In a lode, 
associated, or mixed, with anthracite. 
The lode was worked to a depth of 
ten fathoms, when the walls closed | 
in and cut it out. 
Wexford. 7 | Ballymoney. Courtown —Ordovician.—Disseminated — 
in beds of black shale. aa 
i 20 | Greenfield. Enniscorthy— Ordovician. 
i. 25 | Craan. Wilton—Ordovician.—In a vein, asso- | 
ciated with anthracite. 
ss 31 | Doonoony. Taghmon — Ordovician. —In a vein, 
associated with anthracite. 
Wicklow. 80 | Rathdrum. N.E. of Rathdrum, Ovoca—Ordovician. 
a 35 | Avondale. —In these places it occurs dissemi- 
3 35 | Cronebane. nated in black shaly clays locally 
called Coal-ground. 


Kinanan—On Irish Metal Mining. 251 


NICKEL. 


[This mineral as yet has not been found in sufficient quantities to be profitable. It has, 
however, been detected in the pyrrhotites of the Maam and Gleninagh Valleys, 
Co. Galway. Hardman has found it in serpentine or allied rocks ; such as ophiolyte, 
Lissoughter ; tadeyte (?) Mullaghglass, Co. Galway ; ophyte, Croagh Patrick; steatyte, 
Bofin, Co. Mayo; and ophyte, or eklogyte, Slishwood, Co. Sligo. 

In America there is a magnesian rock which is worked profitably for the nickel it 
contains ; therefore attention may be directed to a rock found 8.W. of Leenaun, to 
the north of Glenisky Peak, Co. Galway, and to a similar one in Achill Island, 
Co. Mayo; as in appearance they are very like the American rock. As yet neither of 
these have been tested for nickel. 

Magnetic pyrites (pyrrhotite) crystals that occur at Barnesbeg, Co. Donegal, were 
found by Scott to have traces of nickel and cobalt. ] 


TITANIUM. 


[Titanium is rare in Ireland, or has not been recorded. Specimens of rwtilite, or rutile, 
the native oxide, have been found at Cushanacurragh, near Burrishoole, to the north- 
east of Clew Bay, Co. Mayo. In the Co. Donegal, Sir C. Giesecke records it as found 
in quartz peebles, River Dale, and in mica slate, Arranmore, while Mr. J. V. Stewart, 
records it at Malinbeg and Ards. Recently bunches of small crystals have been 
found in Rosscuile, in the same county. ] 


MOLYEBDENITE. 


[| Phis mineral appears to occur in rather considerable quantities disseminated in a wide 
endogenous granitic vein in the townland of Murvey, near Roundstone, Co. Galway 
(sheet 63). Elsewhere it does not appear to be recorded in quantity. Haughton 
found it in oligoclase veins at Garvany, near Castle Caldwell, Co. Fermanagh; 
while R. H. Scott found it in an elvan at Lough Laragh, near Glenties, and 
J. V. Stewart at Lough Anure, both in the Co. Donegal. ] 


ALUM AND COPPERAS. 


(Alum shales frequently occur in the Lower Coal Measures, especially in the Province of 
Munster, while pyritous shales, suitable for the manufacture of copperas, are also 
found, especially in the Upper Coal Measures. 'To the pyritous shales special attention 
was directed by Kane, in 1844, but since then no one seems to have endeavoured 
to utilize them. Near Castleisland, Co. Kerry, are pyritous shales, called Lapis 
Hibernicus Auctorum ; these at one time were used in the manufacture of copperas at 
Tralee. 

Some few years ago Mr. Walter Jameson, of Glenarm, discovered an alum-clay 
(alumyte) in connexion with the lithomarge and iron ores of the Co. Antrim, This is 
at present worked in different places, but more especially near Ballintoy. 

‘The alumyte must not be confounded with the French Beauaxyte, or the German 
Woheiryte, both of which are ferriferous, and in aspect more or less similar to some 
of the varieties of the Antrim lithomarge and bole. The lithomarge and bole have 
not as yet been worked for alum; yet they seem to be allied to the alumyte, the 
latter appearing as if it was a secondary product ; having been at first lithomarge, 
out of which the iron was leached by the associated lignyte, as the alumyte is always 
accompanied by the latter.—See County History. ] 


252 


salt. ] 


Scientifie Proceedings, Royal Dublin Society. 


SALT AND GYPSUM. 


[In Ireland salt and gypsum are only found in the Triassic rocks of two counties, and 


are more or less associated. the 
borings, gypsum has been found; but in different places the latter occurs without 


In all the sinkings for salt, although not in the 


CounrTIESs. 


Antrim. 


Tyrone. 


Monaghan. 


No. of 
Ordnan’e 
Sheet 


20 


41 


53 


52 


63 & 
67 


30 


Locatitizs. 


REMARKS. 


Cushendall. 


Ballylig. 


Eden. 


Dunerue. 


Mullaghearton, or Mul- 


tikartan. 


Coagh. 


Derrynasrobe. 


Knocknacran. 


Raloaghan. 
Neweastle. 
Keernaghan. 


Near to . . —Gypswm.—Found in the 
“ Keuper Marl.” 


Three miles south-east of Larne.—A 
bore-hole was put down in 1839, 
while making trials for coal, to a 
depth of 174 feet; at 150 feet Salt 
Measure was met, but the trial was 
abandoned before it was proved if 
a good bed of salt existed. 


On Belfast Lough. <A Salt Spring at 
the village. 


Carrickfergus—Salt and Gypsum.—The 
Salt Measures, discovered ina trial in 
search of coal. In the old pit these are 
162feetin thickness, contain 110 feet of 
pure salt, and 13 ofrock-salt; butin the 
new pit, 600 yards to the north, they 
are only about 100 feet thick ; while 
to the 8. W. of the old pit trials have 
been made without finding the Salt 
Measures. These data suggest that 
they are in a lenticular mass, or cake, 
of limited extent. The best salt-bed 
(88 feet thick) containing over 95 per 
cent. of pure salt. 


Lisburn, Valley of the Lagan—Gypswm. 
—Recorded by Rutty in his Natural 
History of Dublin, 1772. Gypsum 
is known to exist in different places 
in the valley. 


S.S.W. of . . —In a pit sunk at the 
south side of the Ballinderry River 
thin seams, or beds, of fibrous gyp- 
sum occur in a red and green marl, 
15 feet thick. 


Carrickmacross.—A cake of gypsum. 
In one place upwards of 60 feet 
thick. Was manufactured at Knock- 
nacran into Plaster of Paris until the 
works were burnt down prior to 1870. 


S.E. of Kingscourt—Gypswm.—Proved 
by borings in the first townland ; 
raised in the two others. 


Kinanan—On Trish Metal Mining. 


203 


APATITE. 


[Apatite in quantity has not as yet been recorded in Ireland; but as some of the rocks are 


very similar to those associated with the apatite in Canada, especially some of the West 
Galway rocks, it may yet be found. ] 


REMARKS. 


CountTIES. ae 3 Locatirizs. 
45a 

Antrim. — — 
Donegal. 27 | Craanford. 

3 37 | Carn High. 

30 85 | Barnes, Upper and 

Lower. 

Galway (?) — | West, or Yar-connaught. 
Tyrone (?) — | Sheve Gallion District. 


In the Lias of the east coast some 
nodules (coprolites) have been found, 
but not in quantity. 


Millford—Ordovician.—A poor apatitic 
limestone. 


Rathmelton — Ordovician.—A_ slightly 
apatitic limestone. 


Kilmacrenan—WMetamorphie Cambrian(?) 
Scott records having found traces of 
apatite in these townlands. 


Ordovician (?) or Cambrian (?)—Some of 
the rocks in both these areas are very 
similar to those, that in Canada, are 
associated with the apatite. 


204 Scientific Proceedings, Royal Dublin Society. 


STEATITE AND PYROPHYLLITE. 


[Steatite and pyrophyllite generally occur more or less deteriorated as the rocks,—steatyte 
(soapstone), and pyrophyllyte (camstone). They are very much confused in the records, 
both nearly invariably being called by the first name. Steatyte is for the most part 
made up of silicate of magnesia, and nearly invariably occurs as an adjunct of the 
intrusive rocks; although in some cases a “fault rock,’ made up of the debris of 
intrusive rocks may become a steatyte. They may pass into talcyte. The rock 
pyrophyllyte, is for the most part made up of silicate of alumina, and nearly always 
occurs in beds, as if it was a methylotic sedimentary tuffose rock. Nearly invariably 
it has a fibrous or elongated prismatic structure, and often passes into sericyte, or 
anhydrous micalyte. 

The largest and most valuable recorded Irish localities for steatyte are in the Co. Mayo; 
while pyrophyllyte is more known in Donegal than any other country. Beds of 
steatitic clay, or ‘‘ Fuller’s earth’’ are found in different places, and formerly were 
much used for abstracting grease from woollen articles, while in the Co. Galway they 
are still used for that purpose. Pyrophyllyte has been used in the manufacture of 
lubricators, but as it contains about 30 units of alumina, it might possibly also be 
utilized in the manufacture of alum and alumina. Neither steatyte nor pyrophyllyte 
have been carefully looked for or recorded. The following list, therefore, may tall 
considerably short of the number of places in which they occur. ] 


CounrTIEs. EE Locatirits. | Remarks. 
|45u | 
Antrim. 47 | Gobbin’s Rock, Island | LHocene (?)—Steatyte.—Formerly exten- 
Magee. sively used for French chalk. 
Cork. 128 | S.W. of Dunboy. Castletown, Bearhaven—Carboniferous 

Be 127 | Pulleen Harbour. Slate.—These, especially the first, 
appear to be dykes; the latter is 
cupriferous. Both seem to be more 
of the nature of pyrophyllyte than 
steatyte; but as yet have not been 
tested. 

Donegal. 37 | Meenrea. West of Rathmullen—Ordovician (?)— 
A bed of pyrophyllyte. 

5 17 | Kildrummon. South of . . —Ordovieian.—The back 
of a bed of pyrophyllyte exposed at 
the shore. 

ae 45 | Cloony. N.W. and N. of Rathmelton—Ordovi- 

ra 46 | Carn. cian(?)—A bed or beds of pyrophyl- 


lyte: worked along the back, or 
outcrop, for clay to be used, as 


hearths. 
. 44 | Clonkilty. Westward of Kilmacrenan — Ordovi- 
53 44 | Cottian. cian (°?)—In several places in the 


hills. In general the pyrophyllyte 
of the Co. Donegal is called camstone 
or cambstone. It has been quar- 
ried for architectural purposes.—See 
Wilkinson’s Practical Geology. 


Kinanan—On Irish Metal Mining. 200 


CountIrs. Locauirigs. REMARKS. 


No. of 
Ordnan’e 
Sheet 


aS 
iS 


Donegal. Carrowtrasna. West of lLoughakib, Church Hill 
(Gartan)—Cambrian.—A bed of pyro- 
phyllyte. Mined for some years pro- 
fitably, and sold in the market under 


the trade-name of ‘‘ steatyte.”’ 


sy 58 | Crohy Head. Dungloe—Ordovician(?)—Beds of pyro- 
phyllyte (2 ): for some time mined 
to be used in the manufacture of 
lubricators. 


* 52 | Cabra Glebe. S.E. of Churchtown — Ordovician.— 
Pyrophyllyte bed: seems to have 
been worked in old times, but no 
opening has been made for many 
years. Adjoining the old working 
is a heap of peculiar saucer-shaped 
pieces of slag. 


79 | Gibbstown. W.N.W. of Castlefinn—Ordovician.— 
Pyrophyllyte, or ‘‘camstone,’’ has 
been raised for years; in old times 
for architectural purposes, and more 
recently solely for slabs for furnaces. 
Camstone veins also occur in the 
country to the northward, between 
Castlefinn and Letterkenny, that 
appear to have been used for farm pur- 
poses. 


Galway. 25 | Kilmeelickin. Maumbridge — Ordovician. — Tumblers 
and fragments of steatyte (?); the 
source not proved. In other places 
in this county small veins of steatyte 
are recorded as associated with the 
ophytes, but no considerable accumu- 
lation is recorded. 


Mayo. 87, | Croagh Patrick Range. Westport—Ordovician.—Small accumu- 

&e. lations and veins of steatyte, asso- 
ciated with the ophyte that forms 
the long tract (the largest in Ireland) 
extending from the N.W. slopes 
by Croagh Patrick to eastward of 
Westport. No large or pure vein, 
or pocket, is recorded. 


65 | Claggan. Achill Island—0Or dovician. —An i irregu- 
lar bunch, or ‘‘pocket-vein,”” of 
steatyte. vA portion is crystalline 
and very pure: has been worked to 
a small extent. 


256 Scientific Proceedings, Royal Dublin Society. 


LocaLitigs. REMARKS. 


No. of 
Sheet. 


YL 
q 
CounTIEzs. | A 
6 


Mayo. 107| Lugaloughaun. Westport — Ordovician.— Pockets and 
veins of steatyte, associated with 
ophiolyte: first records by Warren. 
[Geological Survey Mem. Ex. Sheets 
83 and 84, page 49. | 


106| Glencullian. (Doolough) Louisburgh—Ordovician.— 
A dyke of mottled-green steatyte. 


5 106} Clegganadodda. Louisburgh — Ordovician.—A large 
yellowish mass, associated with an 
intrude of felstone; appears to be 
in part pyrophyllyte, and in part 
steatyte. 


” 114| West Quarter. Bofin Island—Ordovician.—This island, 

as also Shark, lie off the coast of © 
Galway, although in the Co. Mayo. 

A very important and large mass of 

steatyte, having in places very pure 

veins and pockets: has been worked 

a little. 


114} N.W. Coast. Shark Island — Ordovician.—A large 
mass of steatyte; very similar to that 
on the opposite shore of Bofin. 


Wicklow. 39 | Killahurla. Woodenbridge—Ordovician.—Dykes of 
an orange or yellow steatyte. In 
this county, also in Wexford and 
Waterford, associated with the basic 
eruptive rocks, are small veins of 
steatyte, but none of those recorded 
are of a size requiring a special 
notice. 


af 17 | Glenmacnass. S.E. portion—Wetamorphie Cambrian(?) 
Pyrophyllyte (camstone) ; formerly 
(1837) worked for chimney-pieces, &c. 
The stone when first raised was quite 
soft, but after being cut rapidly 
hardened. 


Notr.—Steatite and Pyrophyllite in this list are minerals, while Steatyte and Pyro- 
phyllyte are rock masses: that is, the minerals incorporated with impurities, as found 
forming beds or veins. 


‘Kunanan—On Irish Metal Mining. 


FLUOR OR FLUORSPAR. 


2070 


Fluor or Fluorspar should be mentioned among Irish minerals, being an important 


flux in the reduction of iron. 


Unfortunately its value, until recent years, was not 


generally known, and the places in which it has been found are only sparingly re- 


corded; while a search for it has not been made. 


Among the records, we find it 


mentioned as occurring in several of the lead mines in the Co. Clare; at Minna and 


Juverrin Mines, Co. Galway, of a violet colour; and in the same county, at Glengoola, 


of pale yellowish-green or bluish colour; while in the Mines of Glendalough, Co. 


Wicklow, it was found both crystalline and massive. 


None of the records, however, 


state that, as yet, it has been found in sufficient quantities to be of commercial value. 


Alum, . 
Antimony, 
Apatite, 
Arsenic, 
Barytes, 
Cobalt, 
Copper, 
Copperas, . 
Fluorspar, 
Gold, 
Graphite, . 
Gypsum, . 
Iron, Bedded, 


SCIEN. PROC, R.D:S.—VOL, V. PT. LV. 


PAGE 
251 
248 
253 
249 
235 
249 
222 
251 
257 
205 
280 
252 
237 


INDEX TO MINERALS. 


Tron, veins, 
Lead, . 
Manganese, 


Molybdenite, . 


Nickel, 


Salt, 
Silver, . 
Steatite, 
Sulphur, 
Tin, 
Titanium, . 
Zinc, 


Pyrophyllite, 


> 


PAGE 
240 


209 
247 
251 
251 
254 
252 
207 
204 
231 
207 
251 
209 


258 Scientific Proceedings, Royal Dublin Socicty. 


Part I].—Brier Country Histories. 


TuxEsE County Histories are placed in alphabetical order. In 
Part I., THe Lists or tHE Minzrat Locaririzrs—places where 
salt, gypsum, steatite, pyrophylite, and other useful products oceur— 
are given, as the workings to obtain them are included under the 
general name of “Mines,” although legitimately speaking they 
do not belong to “ Metal Mining.” On the same principle the 
localities for coa7 ought to have been mentioned, more especially as 
the coals are more or less connected with clay-iron-stone. Coal 
workings, however, are so important that universally they have 
been separated from Metal Mining, and have been given a distinct 
place of their own. Nevertheless, in these County Histories, it 
seems impossible to pass them over; they will, therefore, be 
briefly referred to, in the Counties in which they occur, in con- 
nexion with the iron-ores, the working of both being more or less 
connected. The Irish coals are of Hocene (7), Carboniferous, Or- 
dovician, and perhaps of Cambrian ages. 

Some of the statements made hereafter have not been’ verified, 
and in such cases the authorities will be mentioned. Much infor- 
mation can be learned from Lewis’s Yopographical Dictionary. 
The name of the writer of the geological descriptions is not given ; 
but, as tar as I have been able to test them, they appear trust- 
worthy. Unverified statements, however, will be given on Lewis’s 
authority. 

The English writers on Ireland, such as Spencer, Raleigh, 
Ledwich, Boate, and others, insinuate, or positively state, that the 
Trish, before the English came to the country, were perfectly 
incapable of finding or working minerals. ‘This, however, the 
researches of the Antiquarian have proved to be perfectly incorrect, 
as the early Irish were eminent workers in gold, silver, brass, and, 
I believe, iron. Their trade degenerated, and perhaps altogether 


1 From the style adopted in these descriptions, I would suggest that Weaver was 
probably the writer. 


Jaxnanan—On Irish Metal Mining. 259 


ceased, during the internal wars before and after the advent of 
Strongbow and his mercenary companions. The statements of 
these writers as to early mining cannot, therefore, be relied on, 
although they may be quoted in reference to works that were in 
existence when they wrote. 

In the early times gold and silver were recognized productions, 
especially gold, as pointed out in the Paper by the late Gerrard A. 
Kinahan, On the mode of Occurrence and Winning of Gold in Lre- 
land (Proc., R. D.8., vol. 111., pt. v.). The English, prior to 1640, 
discovered and worked three silver-lead-ore veins in Antrim, Sligo, 
and Tipperary. The site of the mine in Antrim is now unknown, 
but probably it was somewhere in the Ballycastle Metamorphic 
rocks district. The Sligo mine was in Coney Island, but it also 
appears to be now unknown, or to be given a different name; 
while that in Tipperary was the Silvermines near Nenagh. The 
last, although claimed as an English discovery, had previously 
been worked by the Irish. 

Boate (16) would have us believe that the English were the first 
to smelt and work iron. Chicester, however, in his report (1609), 
states he found, in Ulster, smiths at work, making steel out of the 
native iron, which they wrought much more easily than it could 
be made in England. The English and Scotch however, who 
came over after his report, developed an extensive trade; which 
seems to have been at its maximum at the time of the rising in 
1641. 

The Iron-works were of different kinds: some Iron-masters had 
furnaces and mills; others, especially in Ulster, smelted the iron in 
bloomeries at the places where the timber was most plenty; while 
others had their furnaces near the coast of Ulster, Connaught, and 
Munster, importing most of the ore from England and Scotland. 
The principal Iron-masters at this time, whose names are recorded, 
were—Lord Cork, furnaces, mills, and mines in divers places in 
Munster ; Wandsworth (Wandesford), furnaces, mills, foundry, 
and mines, Carlow and Kilkenny ; Sir Charles Coot (Coote), mines 
and works, Queen’s County, Leitrim, and Roscommon ; Lord London- 
derry, mines and works, Queen’s County; Lord Hly and Piggot,' 


1 Piggot’s works may haye been in the Queen’s County.—(See description, King’s 
County, page 285). 
T 2 


260 Scientific Proceedings, Royal Dublin Socicty. 


mines and works, King’s County ; Sir John Dunbar and Sir 
Leonard Bleverhasset (Blennerhasset), mines and works, Fer- 
managh ; London Company, mines and works, Clare, Limerick (2) ; 
Sir William Petty, works, Kerry; Lord Stafford, mines and 
works, Wicklow and Carlow(?); Rennie, mines and works, Lon- 
donderry and Tyrone; and Sir Walter Raleigh, mines and works, 
Waterford. 

Boate states that the large furnaces and works, except those on 
the coast-line, were each built convenient to a mine; while the 
bloomeries were moved from place to place, where the fuel was 
most abundant. We may therefore suppose that formerly 
iren-mines existed close to most of the above-mentioned 
furnaces. 

The majority of these iron-works were destroyed in 1641, 
during the troubled times; but many of them were afterwards 
reinstated, while other works and mines were also started. 

Later in Wicklow an Englishman of the name of Bacon erected 
works at Shillalagh, and introduced the importation of pig-iron 
from Wales. These works were carried on by his son-in-law 
Cholmondeley, who changed his name to Chamney, and the latter, 
or his descendants, are said at one time to have had fifty-two 
works, between founderies, mills, furnaces, and bloomeries, in the 
counties Wicklow, Wexford, and Carlow; the Chamneys, besides 
importing ore, worked mines in different places. In Cork, at 
Coomhola and Roaring Water, were the mines of the Whites. 
In Clare and Galway, the Bradys of Raheen, the Burkes of 
Marble Hill, and others, opened new mines and established 
works; while in Mayo, the Gildeas of Port Royal were large 
Tron-masters. There were also elsewhere mines and works, that 
sprung up, to die out subsequently, as the forests were gradually 
exhausted. At the present time the Bog-iron-ore is exported from 
Donegal, Londonderry, and elsewhere, to be used in the puri- 
fication of gas. The raw product, in itself, is of little value; 
but after it has taken up the gas impurities the ‘Gas Wastes,” 
as it is called, is so valuable that the exporters find it profit- 
able to supply, free of cost, the Gas, on the condition that 
they are returned all the “Gas Wastes.” The latter are used 
for the manufacture of very pure sulphuric acid and brown 
paint. 


Kinanan—On Trish Metal. Mining. 261 


Coal must have been worked at a very early time in Antrim,’ 
but the English were the first to discover and work it elsewhere. 
Between 1630 and 1640 coal was discovered by Christopher Wan- 
desford at Idrone in the Co. Carlow, while rising iron-ore; subse- 
quently (1728) it was looked for and found in Coolbawn Hill, 
Co. Kilkenny; but it was not till later, when the woods began 
to be exhausted, that elsewhere it was more generally looked for 
and found. 

The geological sketches at the beginning of each county 
description are necessarily very brief, and many important details 
have had to be quite ignored. 


ANTRIM. 


The rocks of this county belong to the Cainozoic, Mesozoic, and 
Palaeozoic Periods ; but the exact groups to which the first and last 
belong have not been determined. The oldest rocks are metamor- 
phosed, and may possibly be of Ordovician age, but probably are 
Cambrian. Next to them are rocks belonging to the Calp group of 
the Carboniferous, while the Mesozoic is represented by portions of 
the Trias, Jurassic, and Cretaceous. The Cainozoic consists nearly 
solely of sheets of Doloryte and their adjuncts, and in the latter 
are plant remains, that, some say, indicate a Miocene, others, an 
Eocene age. 'The mines worked have been principally for coal and 
iron, while at the present time alum-clay (alwmyte) is also a source 
of industry. 

In the Eocene (?) are beds, or portion of beds, of coal (ignyte). 
alumyte, litomarge (ferriferous clay), bole (aluminous limonite), and 
iron-ore (limonite and magnetic); with steatyte, near the Gobbins 
Island Magee. Various attempts have been made to work the 
lignyte profitably, but all seem to have failed. In the alumyte 
works (although in some of the mines there is a considerable thick- 
ness of lignyte) it is considered perfectly valueless, and is run out 
on to the attals (spocl, or waste heaps), or is used as filling stuff 
in the old workings (stwils). 

The probable origin of the alumyte (alum-clay) has been given 
in a Paper on the “Irish Crystalline Irish-ores,” Scien. Proc., 


1 The coal mines in Antrim seem to have been the oldest in England, Scotland, or 
Treland.—(See Co. Antrim, page 264.) 


262 Scientific Proceedings, Royal Dublin Society. 


Ji. D. 8., vol. 1v., 1884, p. 311, and need not be here re-given. 
At the present time only this clay is worked for the manufacture 
of alum, although the associated lithomarge and bole are very 
similar in aspect to the ferriferous varieties of the French and 
German clays (beauryte and woeheinyte). It would, therefore, 
appear expedient that the bole and lithomarge should be more 


minutely tested, especially the light-coloured varieties of the 
latter. 


The mining in the alum-clay (alumyte) is quite of recent date. 
Its value was first discovered by Mr. Walter Jemerson in 1873, 
who began to work it in 1874: since then the trade has largely 
developed. 

The following are analyses of the alumyte, beauxyte, and 
woeheinyte, procured through Mr. Jemerson :— 


Alumyte. | Alumyte. | Beauxyte. | Beauxyte. Baa. 

Glenarm. | Ballintoy. | Dahm’s. | Margeilleo. 
Alumina, . : 42°45 52°37 63°19 67°83 57-04 
Peroxide of Iron, 1°54 129 3°72 00°47 1-08 
Lime, . 4 ; 0°46 0-48 — — — 
Magnesia, . i Trace. Trace. - -- = 
Potash and Soda, 0:04 0:06 — — — 
Silica, . : 5 27°50 13°16 11:47 10°64 19-60 
Titanic Acid, . 9°40 OO) fu = = 
Sulphuric Acid, . G08) 7 min Or 5m hne aed eh 
Phosphoric Acid, None. None. — — — 
Organic Matter, . Trace. Trace. | — = — 
Combined Watcr, 18-53 27°13 16°32 15°80 17°46 

100-00 100-038 — — — 


The analysis of the alumyte was made by John Pattison, 
Noweastle-on-Tyne. In the French and German analyses the 
alumina is both hydrated and anhydrous. As sulphuric acid, in 
the process of alum making, only extracts the hydrated alumina ; 


Kinanan—On Irish Metal Mining. 263 


in the continental minerals, by all known processes, there is a loss 
of from 6 to 8 per cent. that cannot be abstracted; on this 
account the Irish clays compare much more favourably with the 
continental than the Table suggests. Many of the beauxytes and 
woeheinytes contain much more iron than the above, iron having 
been made from a variety of the latter. Of beauxyte Dana gives 
three analyses; containing of iron respectively, 27-6, 3:0, and 34:9 
per cent. The Irish clays contain much more silica than is found 
in the French or German. The Beauxyte, however, which gave 
3°0 Iron is white in colour and gives 21-7 of silica. 

The Canizoic (Hocene ?) iron-ore trade is also of recent develop- 
ment. In 1609 Chichester mentions ore, while in 1683 Dobbs 
uggested that it existed in Island Magee; but it would appear 
that it was not generally known before 1861, when Dr. Ritchie 
specially directed public attention to those iron-ores. Afterwards 
they were successfully worked, until the slack in the iron trade, 
since which time, although not as successful as previously, there 
is a sufficient demand for the ore to keep some of the workings still 
going.! The occurrence of the pisolitic-ore is peculiar ; for, although 
it appears asif bedded, its genesis probably was long subsequent to 
the formation of the associated rocks. The pisolitic iron-ores fill 
horizontal shrinkage fissures, the accumulations having characters 
more or less analogous to those of standing lodes.—(See Scien. 
Proce Ds S., vole ive, 1884p. 312.) 

The steatyte at the path to the Gobbins Island Magee was 
formerly worked as “‘ French chalk.” 

In places the doleryte is decomposed into a rich ochre. Of 
ochre found at Mr. M‘Arthurs, near Ballymena, Apjohn writes : 
“The silex of the basaltic ochre is at present in a state of 
extreme division ; and from this circumstance, and the great depth 
and beauty of its colour, it appears well suited to the purpose of a 
red paint for gates, railings, and other descriptions of outdoor 
work. 

The Jurassic beds (Lias) are very sparingly represented ; but in 
them are apatitic nodules (phosphates). ‘These, however, have not 
been found in sufficient quantity to be utilized. 


1Quite recently (1885) arrangements have been made to work an accumulation 
found in Rathlin Island. 


264 Scientific Proceedings, Royal Dublin Society. 


In the Trias, near Cushendall ; in the Forth River Valley; in 
the Woodburn Valley, between Kilroot and Whitehead; and in 
the Valley of the Lagan, gypsum occurs in the marls; but 
although the veins in places are numerous, none that are known 
are thick enough to pay for working. 

The Salt mines at Duncrue are of recent date, the salt having 
been discovered in 1850 while boring in search of coal. As 
mentioned in Part I., page 252, the Salt Measures may extend east- 
ward towards Eden, and northward towards Larne, as saline wells 
are found in those directions. 

In remote and recent years there have been workings for coal 
and iron in the Batiycasrie CoaL-rieLp. The rocks are com- 
monly called Coal Measure; but correctly they are a portion 
of the Calp division of the Carboniferous limestone: they are, 
however, the equivalents of the so-called ‘ Lower Coal Measures ”’ 
of Scotland. The earliest works were during the time that 
“stone implements”? were in use, as about 1770, during the 
mining operation, then in progress, old galleries, having in them 
wicker-work baskets and stone implements, were broken into. 
In recent years the Macgildowneys were those who worked the 
coals, the royalties at the time belonging to the Boyds. 

At what time, or by whom, the ancient galleries were driven is 
now unknown; but it is evident the industry ceased and was 
forgotten. In 1700, Ballycastle! was quite a poor place, contain- 
ing some sixty-two house-holdings, and extending over an area of 
about three acres. But about the year 1784 it had advanced, and 
became a prosperous town, having its iron works of various kinds, 
its manufactures of salt and soap, its weaving and bleaching 
establishments, its tanyards, its glass-house, and brewery. The 
enumeration of these is in part foreign to the present inquiry; but 
as they were in a great measure adjuncts of the mining operation, 
it may be allowable to refer to them. 

The prosperity of the place was in a great measure due to the 
energy of Hugh Boyd, the proprietor, and it began to decline 
about 1670 or 1680, after his death, the decline being aided by 


' This place got its present name from the castle built in 1609 by Randolph, Earl 
of Antrim. Correctly the coal and iron works should be called the Culfeightrin 
collieries ; but this name has been quite superseded by that of Ballycastle. 


Kinanan—On Irish Metal Mining. 265 


the London Society (Londonderry) having successfully opposed 
a grant of money to improve the port. 

It may be mentioned that the glass industry seems to have 
been of a very ancient date, possibly prehistoric, as some au- 
thorities suggest that this was one of the places in which the 
ancient glass beads and such like were made. It was induced by 
the excellent sand of the vicinity, due to the weathering and 
washing of the sandstones of Carboniferous age. The glass trade, 
which was principally an export one to Scotland, gradually declined 
as the native coal increased in price, and seems to have finally 
ceased in 1850, or thereabouts, when the glass-house was destroyed 
by lightning. 

The higher coals, or those above the level of the sea, are 
worked out. There are, however, two coals, called the “sea-coals,”’ 
below the sea level, still unwrought ; which have been estimated to 
contain about 18,000,000 tons of coal; but as far as triais have 
been made they are unprofitable, on account of the drainage of 
the sea into the workings: very little, therefore (if any), of this 
coal can be profitably raised. 

Mr. Knowles of Ballymena has found prehistoric beads made 
of sotsite, or jade de saussare (saussaurite), in the Alolian sands in 
places along the coast-line in connexion with Kitchen midding and 
such like early traces of man; while Mr. M‘Henry has discovered 
small veins of similar jade in the metamorphic Cambrians(?). 

In, or associated with, the older rocks (Iletamorphosed Cambrians?) 
gold is said to have been found in Glendun, near Cushendun; and 
in 1825 the Glenarm and Antrim Mining Association proposed to 
work the gravels of the river. This Company are also reported 
to have found in Sheve-an-orra and neighbouring hills, traces of 
copper and lead; but the extent to which they carried their 
researches in quest of these minerals is uncertain, as there are 
not any published records of the places where these minerals were 
found. 

As already stated, in this county was situated one of the three 
lead mines discovered by the English prior to the rising of 1641; 
whereabout it was situated Boate does not state, but he gives a most 
glowing description of it, stating: ‘for as much as with every 
thirty pounds of lead it yielded a pound of pure silver.” At the 
present time it 1s quite unknown. 


266 Scientific Proceedings, Royal Dublin Seaery. 


In the National Museum, Leinster House, Dublin, are some 
fine specimens of Onyx, said to have come from Rathlin Island. 


ARMAGH. 


The major portion of this area is occupied by Ordovicians in 
part metamorphosed with which to the 8. E. are associated Grranyte 
and allied rocks. These to the N. W. are succeeded by Carboni- 
Jerous limestone, while the latter, at the N. W. of the county, are 
overlaid by Triassic sandstone or marl, and to the N. E. by the 
Tertiary or Cainozoic rocks or the Lough Neagh beds. Some of the 
rocks near Armagh and to the N. HE. at Benburb have been said to 
be Permian: their position and fossils, however, seem to prove this 
conjecture to be erroneous. 

The recorded minerals occur nearly solely in the Ordovicians or 
the associated Giranyte and allied rocks. The principal mineral in 
the lodes was lead, but copper occurred in the veins at Jerret’s Pass, 
near Newry, and Tullydonnell, near Crossmaglen. Griffith records 
an ancient mine at Ballymore, near Pointzpass, but states its 
“exact position is not ascertained.” | 

Lewis reports antimony as having been “found in a few 
spots.” 

Westward of Slieve Gallion in the western slopes of the hill 
near Larkin’s mill, and not far from the edge of the Granyte, 
either Steatyte or Pyrophyllyte, probably the latter, has been found. 


CaRLow. 


_ The major portion of the area, included within the limits of 
Carlow, is occupied by Granyte, a part of the Leinster range. To 
the extreme S. W. of the county is a small tract of Coal Measure a 
portion of the KinkENny Coat-FIELD, which lies on the Carboni- 
Jerous limestone of the valley of the Barrow, the latter overlapping 
the Granyte. ‘These limestones are supposed to lie direct on the 
Granyte ; but a few small outlyers of Carboniferous Sandstone have 
been found, which may suggest that elsewhere rocks of this class 
intervene, but are unknown, being obliterated by the envelope of 


Drift. 


Kinanan—On Irish Metal Mining. 267 


Farther northward, in the Co. Kildare, Metamorphic rocks 
(Ordovicians) intervene between the Granyte and the Carboniferous 
rocks, but they do not extend southward into the Co. Carlow; to 
the eastward of the range, however, at Clonegall and Newtown- 
barry a tongue of these rocks extends from the Co. Wexford into 
this county. 

This county does not appear in Griffith’s lists; but in the Coal 
Measure there are some seams and nodular beds of clay-iron stone 
that were mined between 1600 and 1641 by Christopher Wands- 
worth (Wandesford) ; who had also works, including a foundry for 
ordnance, at Idrone.—(See Leinster Coal-field,Co. Kilkenny). In latter 
years iron was raised near Shillalagh, Co. Wicklow, and probably 
also in this county. 

Except the clay-iron stone there are no authentic records of 
minerals or veins. Gold, indeed, is said to have been found not 
many years ago in one of the valleys N. H. of Graguenamanagh : 
this has not, however, been authenticated. Lead is also said to 
have been found in one of the same valleys, and some trials were | 
made unsuccessfully. It may be pointed out that these trials were 
injudicious, and not in the places where lodes would probably be 
found. 


CAVAN. 


About Lough Sheelin, at the south of the county, and extend- 
ing in from Westmeath, is the edge of the great central tract of 
Carboniferous Limestone, while in the vicinity of Stradone there is a 
small outler. The north-western portion of the area is solely 
occupied by Carboniferous rocks; in places there being Coal 
Measure; as in a small tract between Ballyconnell and Swan- 
linbar; and in the hill country, to the N. W., of which Cuilcagh, 
partly in Leitrim, is the highest summit. At Cavan there is a. 
limited tract of Carboniferous Sandstone, and 8. W. of it is an in- 
trude of Granyte, while the rest of the area is occupied by Ordovi- 
clans. 

The mountain tract to the N. W. is a portion of the ConnavGHT 
CoaL-FIELD ; including portions of the counties Cavan and Fer- 
managh (Province of Ulster), with parts of Sligo, Leitrim, and 
Roscommon (Province of Connaught). As all are part of the one 
field, they may here be described together. 


268 Scientific Proceedings, Royal Dublin Society. 


Tn old times, but more especially in the sixteenth and seventeenth 
centuries,! there was extensive mining, smelting, and milling, of 
iron, which lasted till the woods were exhausted, the fuel being 
wood-charcoal. As the woods disappeared the fires were put 
out, the last extinguished being Drumshambo, Co. Leitrim, 
in 1765. Shortly afterwards, in 1788, the three brothers 
O’Reilly tried to revive the industry, and smelt the iron ore 
with the coal—the first attempt of the kind in Ireland. They 
erected a furnace and mills at Arigna, Co. Roscommon, and sent 
into the market some excellent pig and bar iron; the coal being 
procured at the Rover and Aughabehy collieries; respectively, about 
one and three miles distant. The adventure, however, did not 
prove successful on account of English competition; and after 
passing through the hands of other speculators the enterprise was 
abandoned in 1808. 

In 1818 Griffith made a favourable report of the iron ore of 
the district: this, coupled with his statement before a Committee 
of the House of Commons in 1824, induced the Ivish, the Hiber- 
nian, and the Arigna Companies to take setts for the working of 
coal and iron in the Co. Roscommon. ‘The first and second had 
their mining setts in the Cashel Mountain, or Slieve Curkagh, the 
range of hills north of the Arigna River; while the workings and 
works of the Arigna Company were to the southward of that river 
in the Bracklieve range ; but now more generally called the Arigna 
Mountain, after the name of the site of the furnace and mills. 
Practically the Hibernian Company did no work, the report of 
their surveyor being considered unfavourable. The Irish Company 
opened some pits, the largest being at Tullytawen, where the coal 
for a time gave a profit; but the most extensive works were those 
of the Arigna Company. 

The original works of the O’Reillys at Arigna appear eventu- 
ally to have become the property of the Latouches of Dublin, 
because from them, in 1824, the new Company obtained a lease of 
the works and mines. They commenced work with a large staff of 


1 Before the rising in 1641, Sir Charles Coote, besides his Iron Works at Mount- 
rath, Queen’s County, had others in the counties of Leitrim and Roscommon. ‘The 
Leitrim Works may have been at Creevelea, and those of Roscommon were somewhere 
in the valley of the Arigna, all these works were burnt in 1641. 


Kinanan—On Irish Metal Mining. 269 


English artizans and engineers, and from November, 1825, to May, 
1826, the works were prosperous, some 280 tons of iron being 
manufactured at a cost of £8 4s. per ton. Then unfortunately, 
through some mismanagement, the furnace was choked ; which led 
to an expensive Chancery suit, lasting for ten years, when it was 
decided in favour of Mr. Flattery, who recommenced the smelting 
and manufacture of iron in 1836. Flattery worked for some years 
very spiritedly, opening, besides O’Reilly’s collieries, another at 
Gubberudda, where the coal was of a better quality. But eventu- 
ally he could not compete with the English and other iron-workers, 
and his fires had to be put out. Since Flattery’s time iron has not 
been smelted in the district, but the coal has been worked profit- 
ably for a local trade. 

In the Sheve-an-ierin district, to the east of Lough Allen, 
counties Leitrim and Cavan, the clay-iron stone is richer than in 
Co. Roscommon, and in former times, while the forest lasted, was 
extensively mined and worked, the name of the hill anglice “‘ moun- 
tain of iron,” suggesting pre-historic workings. Since the Drum- 
shambo furnace was put out, in 1765, no iron has been smelted, 
_ while very little work has been done in the coal, apparently on 
account of the great quantity of peat fuel. According to Boate, 
iron was worked, in 1650, “in a place called Doubally,” Co. Cavan, 
and “upon Lough Erne,” Co. Fermanagh. 

To the N. W. of the Co. Leitrim, in the barony of Drumahaire, 
the clay-iron-stone was formerly also extensively raised. Of this 
a considerable quantity was carried to Ballynakill, south-east of 
Colloonoy, and to a furnace near Ballysodare, both in the Co. Sligo, 
to be mixed with other ores and smelted. It was also smelted at 
the Creevalea Iron Works, townland of Gowlaun. In this town- 
land, and the adjoining one of Tullynamoyle, there are various beds, 
or nodular beds, of clay-iron-stone, the richest, as pointed out by 
Griffith and Jukes, being one about eleven inches high, which is as 
good, or perhaps better, than any of the seams in Slieve-an-ieran. 
According to the record, Sir C. Coote appears to have had works 
here in 1640, while the last furnace for smelting iron with wood- 
charcoal, was extinguished in 1768. The works, however, were 
resumed, in 1852, by a Mr. Currie, who, laid out large sums in blast 
furnaces, kilns, tramways, engines, and workmen’s houses; but 
became bankrupt in 1854. Afterwards the woiks were rented by 


270 Scientific Proceedings, Royal Dublin Society. 


Mr. Potts of Dublin, who smelted a little iron with peat charcoal ; 
they, however, were abandoned in 1858-59. 

In this field the amount of clay-iron-stone is considerable: some 
of it, however, is inferior. Of coal there cannot be much; perhaps 
some 10,000,000 tons, of which only a portion could be economi- 
eally wrought, especially during the present low price of coal and 
high rate of wages. The coal in part is gaseous. 

Other minerals in Co. Cavan occur in veins in the Ordovicians, 
such as copper in Farnham, near Cavan, and lead near Cootehill, 
Shercock, and Ballyconnell. 

In the Ordovicians of Kill, near Kilnaleek (sheet 37), there is a 
bed of anthracyte. This, when discovered in 1854, was sank on, and 
according to Dr. Whitty’s report, was, in one place four feet thick. 
This, however, appears to have been a local swelling of the bed, as 
elsewhere in the strike and in depth it was only a few inches wide. 
About two miles southward of Shercock are beds of anthracitie 
shales: these in bad winter, when fuel was scarce, have been worked 
for fireing; they were, however, only a make-shift in the place of 
better, because at present they are of no commercial value. It is, 
however, possible that here, as in Canada, anthracitic and car- 
bonaceous shales may point to underlying oil or gas cisterns. 
This seems worthy of further research. 


CLARE. 


The rocks of this county belong to the Carboniferous and Ordo- 
vivian periods. Nearly half the western portion of the area is 
occupied by Coal Measures, the northern portions of the extensive 
West Mvunsrrer Coa-FreLp ; while to the east, in the neighbour- 
hood of Lough Derg, hills of Ordovician rocks protrude up through 
the Carboniferous. 

In Munster, especially Limerick and Clare, below the Ca/p and 
Fenestella limestone (lithologically divisions of the Carboniferous 
rocks) leady lodes often occur; below the Fenestella limestone 
the lead is usually accompanied, more or less, with copper and 
sulphur ores. On both horizons the minerals do not occur in re- 
gular lodes, but in pockets and “ shoots,’ which, when worked out, 
have no leaders to other deposits. Different, very rich pockets 


Kinanan—On Trish Metal Mining. 271 


have been found on both horizons, which were remunerative to 
the first adventurers, but more or less disastrous to their suc- 
cessors who have attempted to follow what they supposed to be 
“leads.” Pockets of this class are indicated by calespar, associated 
with dolomitic sand. In the limestones of the Burren type 
numerous small veins of lead and zinc have been found, but none 
of them of promise; yet we learn from the records that, in the 
time of James the First, there was a “‘silver-mine”’ in the Burren, 
adjacent to O’Loughlin’s Castle, now called Castletown, while 
there are misty records of much more ancient mines. Fluor or 
fluorspar was found in different mines, associated with the lead, 

In the Coal Measures, near the Shannon, below the horizon of the 
lowest coal, some of the shale-beds are very rich in nodules of clay- 
iron stone. ‘The coals in this county are of very little account. 
Near the Shannon, to the south, there are some thin beds, that 
were worked in old times along the outerops, but as they are traced 
northward they thin, till eventually the horizons are only marked 
by fire-clays, with stems of stigmaria. The iron-ore beds also 
appear to become poorer as they are followed northward. In the 
old times the latter were worked to the southward, in the vicinity 
of the estuary of the Shannon. Some of this ore seems to have 
been smelted in the vicinity of the mines, but much of it was 
carried inland, or was sent up the Shannon by boats, to be mixed 
with Ordovician and other ores at the furnaces on Lough Derg 
or elsewhere. This clay-iron stone is mentioned as worked in 
1650, while it was smelted and wrought by a London Company 
at furnaces and mills near tle mines. 

Iron ore in the Ordovician rocks was extensively raised in 
Glendree, westward of Feakle, also at Ballymahon and Bealkelly, 
near Tomgraney. Hast of Feable, at the hamlet now called 
Furnace, are the remains of considerable works, apparently prin- 
cipally for smelting purposes; while the iron raised at the mines 
near T'omgraney is said to have been sent by boat, to be smelted 
and milled at the different furnaces and works between Mount 
Shannon, Clonrush, and Woodford, west of Lough Derg, Co. 
Galway. According to the records, three classes of ore appear to 
have been in use for mixing at the furnaces, and these, from 
Gerrard Boate’s descriptions, were evidently the bog-iron-ore, the 
ore from the Ordovician rocks, and the clay-iron stone from the 


Die Scientific Proceedings, Royal Dublin Society. 


south of the county and the Co. Limerick. These furnaces and 
mills were at work until the woods were exhausted; the last fire put 
out (Woodford), about the year 1750, belonged to the Burkes of 
Marble Hill.’ . 

In the Ordovician rocks in different places are found, besides 
the iron ore (limonite), small veins and indications of lead, sulphur- 
ore, copper, anthracite, plumbago, &c.; but up to the present 
time none of them have been worked very successfully. 


Cork. 


The rocks of the premier county of Ireland are both interesting 
and peculiar. North of the valley from Dingle Bay, Co. Kerry, 
to Dungarvan, Co. Waterford, there is one type of Carboni- 
ferous rocks, while south of that line there is another. In the 
north-west part of the county, in the Ballyhoura and Galtee 
Mountains, there is Carboniferous Sandstone, within the latter a small 
exposure of Ordovicians. Over the sandstone lies the Carboniferous 
Limestone, and on the latter Coal Measure, a part of the Wesr 
Monster Coa-FIELD. 

But south of Dingle Bay and Dungarvan Valley the rocks 
have lithological characters, more or less peculiarly their own, 
which have lead to various classifications and nomenclature. The 
petrology, or the geological relative positions, of the different groups 
have been very successfully worked out by Griffith and Jukes ; but 
to suit the present ideas their names require revision, or rather modi- 
fication. In this area there is very little hmestone, it only being 
found to the eastward, while elsewhere it is replaced by shales, 
slates, and grits (Carboniferous Slate) ; these towards the west are 
of considerable thickness, being much thicker than the Carboniferous 


1 In the Geology of Ireland (1878), chap. xxi., p. 852, and in other writings on the 
subject, I have suggested as probable that the last furnaces in which wood charcoal 
was used for smelting iron were those of Woodford in Galway and Port Royal in Mayo. 
Since then I find that the Port Royal works appear to have been in existence subse- 
quent to those of Woodford; while in Leitrim and Sligo there were fires alight in 
1764 and 1768, or nearly twenty years later than at Woodford. The fires at Shillalagh, 
Co. Wicklow, were put out a few years before Chamney’s death, which took place 
in 1761. The Port Royal works seem, however, to have been more recent than those 
of Sligo and Leitrim, as, about the year 1860, the old mill was partly in existence, the 
forge anvil being still in sitw.—(See Mayo, p. 290.) 


Kinanan—On Irish Metal Mining. 273 


Limestone of the Central plain. Under the Carboniferous Slate is 
the Yellow Sandstone (Griffith) or Upper Old Red Sandstone (Jukes): 
it graduating downwards into the Devonian or Lower Old Red 
Sandstone, and the latter into the Glengariff Grits (Jukes) or 
Silurian (Griffith). The equivalents of the groups, as nearly as 
possible, are as follows :— 


Cork Tyrer. CENTRAL IRELAND TYPE. 
Carboniferous limestone and 


 CURGVERGUS BHENE, Lower limestone shales. 


3. Yellow sandstone, . . .  Lowercarboniferous sandstone. 
Devonian, or 


| Lower Old Red Sandstone, Lower Devonian (?) (England). 
1. Glengariff Grits,. . . . Silurian. 


The Glengariff Grits are evidently the representations of 
the upper beds of the Silurians of the Dingle promontory, Co. 
Kerry. The Devonian (Lower Old Red Sandstone) are in part the 
equivalent of the Lower Devonians of England. In Co. Cork 
they form a regular unbroken passage from the Carboniferous rocks 
down into the Silurian; but in Slieve Mish, Co. Kerry they 
are only in part represented, the lower strata being absent, while 
the higher ones lie direct, but unconformable, on the Dingle 
Silurian.! Elsewhere in Ireland, except, perhaps, the Fintona 
Mountains, counties Fermanagh and Tyrone, the Devonian rocks 
are not represented. 

The Yellow Sandstone (Upper Old Red Sandstone)’ is an im- 


1 In Slieve Mish, above the unconformability (‘‘Inch or Park conglomerate’’), 
and below the Lower Limestone Shales, there is a thickness of some 5000 feet of 
strata. These must represent part of the rocks (called by me Devonians) below the 
Carboniferous Slate, Co. Cork. This fact seems to be ignored in the proposed new — 
classification of the Cork rocks. 

2 Jukes’ names for the Cork rocks, Upper and Lower Old Red Sandstone, has been 
the cause of considerable controversy in the Mining Community, they apparently not 
understanding that they are petrological or group names, and do not specially refer to 
lithological characters, and that the rocks of the groups may be either argillaceous (shales 
and slates) or arenaceous (sandstones). In Jukes’ groups, as a general rule, argillaceous 
rocks (Killas of the miner) are more prevalent in the Upper, and arenaceous rocks form 
the majority in the Lower. In the Yellow Sandstone, or Upper Old Red, of the 
Co. Cork most of the Copper veins occur, they not being of any value in the Lower 
Old Red. 

SCIEN. PROC., R.D.S.—VOL. V. PT. IV. U 


274 Scientific Proceedings, Royal Dublin Society. 


portant group, as at its base are the Metallic schists and their 
associated copper lodes. 

The above divisions appear to be the true natural grouping of 
the South Cork rocks. Of late another, of a lithological character, 
has been attempted ; but both petrologically and paleeontologically, 
and even in part lithologically, it is evidently incorrect. 

In the extensive Wrest Munster CoAt-FIELD, only in this 
county, have productive coals been found; while here they seem 
solely to occur in a narrow strip along the Blackwater valley. 
Tn this strip the coals stand at a high angle, and appear to be cut 
off in depth by nearly horizontal faults. On this account, unless 
an elaborate system of bore-holes were put down, it is perfectly 
impossible to even guess, at the quantity of unwrought coal. The 
coal (anthracite) is of two distinct qualities—hard and soft—the soft 
flakey kind, or cu/m, being greatly in excess of the hard and more 
valuable variety. The latter is very sulphurous, but gives a 
strong heat. These coals have been working continually for a 
century and a-half. According to the writings of Gerrard Boate 
and Smith, clay-iron stone appears to have been raised here, to 
mix with bog-iron and the Devonian ores, for smelting at the 
furnaces presently mentioned. 

In the Carboniferous Limestone and Sandstones, only a few 
mineral lodes are recorded. 

In the Devonians, however, in the seventeenth century there 
appears to have been a large iron industry. During the time Sir 
Walter Raleigh lived at Youghal, he was an iron-master, having 
mines and works in the Devonians, Co. Waterford; but it seems 
uncertain if he did any work in this county. Lord Cork, however, 
had works in divers places. Smith, writing in 1750, mentions 
Lord Cork’s works at Araglin, near the eastern extremity of the 
county, and those of the Whites, at Coomhola near Glengariff, 
and Aghadown near Roaring-water bay. LBoate, a century earlier 
(1652), states that Lord Cork’s works were near Tullow Bridge, 
and the ores used were of three kinds—bog-iron ore, clay-iron 
stone, and limonite or hematite—the latter probably being raised 
in the Devonian rocks. 

During the present century there has been considerable copper- 
mining, induced principally by Colonel Hall’s discovery, in 1810, of 
a valuable lode at Allihies (Berehaven Mines). These lodes occur in 


Kinanan—On Irish Metal Mining. 279 


the Metalliferous beds at the junction of the Yellow Sandstone and 
the Devonian rocks, and whenever they passed out of the Metallife- 
rous beds, either horizontally or in depth, they became valueless. 
Here the strata occurred advantageously, being in a half bowl, 
across which the lodes (counter Jodes) ran both E. and W. and N. 
and S. Some of the continuations of the lodes at the surface are 
massive, but, unfortunately for the Mines, once they pass the 
limits they lose their copper. These lodes at the first produced 
large returns; but after 1860 they began to fall away, and now 
appear to be nearly valueless.’ 

Elsewhere, in the south of the Co. Cork, there are a few 
counter lodes ; but?most of the copper and other lodes run more or 
less with the strike of the rocks, only cutting across the beds in 
depth. On this account they are not so productive; nor are they 
so continuous in depth; because, when going down, if they have to 
pass through one of the massive grits, they split up into strings, 
and nearly invariably die out. It has been suggested that if these 
massive grits were sunk through the lodes would again be found : 
this, however, seems improbable, because, in some of the cliff sec- 
tions, it can be seen that such split-up veins do not again mass into 
one. Some of the so-called lodes are regular beds of killas, highly 
impregnated with grey copper ore. In different places rich pockets 
have been found close to the surface, while in depth the lode lost 
its minerals. As pointed out by Jukes, the copper is very widely 
disseminated in the rocks, and “it will be obvious thata large 
quantity of poor ore, easily accessible, may be more productive 
than rich ore, or even the metal itself, which is disseminated in 
small quantities, or in situations requiring great trouble and 
expense for its extraction.” In this portion of Cork the lodes are 
very deceptive, and it “is a district where, perhaps more than 
others, requires great caution, as well as skill and prudence te 
mine with profit, and is a most delusive district to the speculator, 
from its containing so many of these specimens of rich ore, many 
of which have not indicated the existence of much more ore than 
was actually seen in the specimens.” 

In the Metallic shales of the Yellow Sandstone the prevailing 


* On account of the Igneous rocks in the vicinity (Cod’s Head, &c.) it is possible, 
if tried in depth, Zin might be found. 
U2 


276 Scientific Proceedings, Royal Dublin Society. 


ores are yellow and grey copper; but when passing from these into 
~ the Carboniferous Slate, and also in the latter, the ore is principally 
lead. There are, however, associated with the copper ores, the 
ores of various other minerals (see Lists) enumerated in Part I. 

A peculiar lode occurs at Glandore and at Rosscarbery. It is 
associated with a dyke of fault-rock, and has a back of iron ore— 
in the latter fissures formed, which are nowifilled with manganese: 
ore. It has been worked both for the manganese and iron, 
but has not been proved in depth. Probably it is a coppery 
lode. 

Within the last few years there has been a*movement in favour 
of the West Cork mines, especially those in’ the Sheeps Head pro- 
montory. Near Kilcrohane, and north-eastward thereof, there 
have been workings on the large coppery sulphur-ore lodes, and on 
some of the bedded grey copper lodes. In these lodes there is a 
considerable quantity of arsenic ore (arsopyrite), and in places the 
carbonate and oxides of copper occur, as profitable “ backs” to the 
lodes. 

There are in some localities large accumulations and veins of 
barytes, while the copper ores at Dhurode (Carrigagat) and Kil- 
crohane (Sheeps Head) are auriferous, while the grey copper ore of 
Lissaremig and Rooska is argentiferous. With the silver-copper 
there is also silver-lead, while in the old workings at Rooska they 
raised a considerable quantity of carbonate of iron (Chalybite), 
which still remains in the atta/s, or waste heaps. 

Anthracite is stated to have been Feu at Twomilebridge and 
Strancally, near Youghal. 

Very good amethysts have been found in places in the Devo- 
nians, and were formerly utilized. 


DONEGAL. 


The principal portion of this county is occupied by Granitic 
and Metamorphic rocks, they having in places on them small 
patches of Carboniferous Sandstones, Shales, and Limestones. The 
Metamorphic rocks, in 1884, were discovered by the late Gerrard A. 
Kinahan to belong to two geological periods, the younger are 
Ordovicians, and the older must be either Cambrians or Laurentians. 


Kinanan—On Irish Metal Mining. 277 


It is not only absurd but also frivolous, to draw in them imaginary 
boundaries, and call a part Laurentian and a part Ordovician, as 
has been proposed. The larger portion of the Granyte is intrusive, 
but associated is some Metamorphic Granyte, and a considerable 
area of Granitic gneiss. 

Since the beginning of the present century various explorers 
have published lists of minerals; but, although examined by so 
many, only a few valuable mines have been discovered. Some 
good silver-lead was found in the Carboniferous Limestone near 
Ballyshannon, and in Metamorphic Limestone at Kalldrum, to 
the south-westward of Dunfanaghy ; elsewhere there are not any 
metal mines of note, although in places there are very fair- 
looking indications. At Carricknahorna, near Ballyshannon, there 
is a lead lode with a “back ” of iron and manganese in the Car- 
pboniferous Limestone: this was worked for the iron-ore in 1884; 
and 30 tons of ore was shipped for Ballyshannon, to Mostyn, on 
the River Dee, by Messrs. Fathem and Kidd. 

Cainstone, or pyrophyllyte, has been recorded in a great many 
places, and the harder varieties were formerly used for archi- 
tectural purposes, while the finer kinds have been mined and sent 
into the market as steatyte. 'Thin beds of anthracyte are recorded 
as having been found at Dromore and Kintale, on Lough Swilly ; 
while gold is said to have been detected in a small quartz lode in 
the stream that flows from Lough Knadas, one mile due east of 
Ballyshannon. | 

As long as the forests lasted iron was largely smelted, and the 
remains of the bloomeries and mills are found in different places. 
Some bog-iron, and perhaps other native ores, were used ; but the 
records state that large quantities of ore were imported into the 
country from Scotland and England. At the present time there 
is an export trade of bog-iron-ore, to be used in the process of 
cleaning gas. 

Very fair beryls occur in some of the exogenous Granyte veins 
§.E. of Dungloe, at Doocharry, and Slieve Snaght, barony of 
Boylagh; while Giesecke reports having found greenish-gray jade 
at Crohy, in the same barony. 


278 Scientific Proceedings, Royal Dublin Society. 


Down. 


The area within the limits is nearly solely occupied by 
Ordovicians, which towards the south are in part metamorphosed, 
having associated with them Granitic rocks of different ages—Or- 
dovician, Triassic (?), and Eocene(?). At the’extreme south of the 
county, also in the neighbourhood of Castle Espie, N. W. of Strang- 
ford Lough, are very small tracts of Carboniferous Limestones. 
On the shore of Belfast Lough is a small exposure of dolomyte,, 
having fossils of Permian types; while in the valley of the 
Lagan, to the N.W. and W. of the county, the Trias is capped 
with Cretaceous and Kocene(?) rocks. 

In the Cainozoic rocks are thin, valueless beds of lignyte, and 
in the Trias gypsum, but in too thin veins to be valuable. | 

In the Ordovicians are numerous small veins and indications. 
of lead and copper, but only in a few places have they been found 
rich enough to work. <A few thin beds of anthracyte have been 
noted in the vicinity of Strangford Lough. 

In early times iron was mined in the Slieve Croob district ;. 
and a few years ago good hematite was discovered at Deehommed, 
south of Banbridge: this mine has still to be developed. 

In exogenous veins in the Triassic(?) Granyte of the Mourne 
Mountains topazs and beryls have been procured ; the localities 
being the N.W. side of the small lake on Bingian, on Slieve 
Havila, and the Chimney Rock Hill. 


DuBLin. 


‘In this county the prevailing rocks are Carboniferous: of the 
Calp type. At Howth and Bray are small tracts of Cambrians. 
West of the latter is the N.E. extension of the Leinster Granyte 
range, flanked westward by Ordovicians, in part metamorphic; 
while at Portraine and Balbriggan there are small exposures of 
Ordoviwicxs. . 

The county is poor in nines, the lodes found, being principally 
lead and copper. In the Granyte at Dalkey, tin is also recorded 
by Griffith. 


KinaHan—On Irish Metal Mining. 2D 


Rich silver-lead, with silver, was found to the south of the 
county, at Ballycorus, and lead at Shankhill and Rathmichael, at 
the vicinity of the junction of the Granyte and Metamorphic 
rocks. ‘These lodes are worked out, but other lodes ought to occur 
elsewhere in the vicinity of the line of junction. 

Gold in small quantities has been found in the Diluvium of 
some of the valleys in the Ordovician. 

Beryls have been found in the neighbourhood of Killiney and 
Dalkey, in Glencullen, on the tmeeliodls Mountain, and at 

Stillorgan. 


FERMANAGH. 


Westward of the valley of the Loughs Erne the rocks are 
Carboniferous Limestone, capped by Coal Measures; while east of 
that valley there are Carboniferous Limestones and Shales over- 
lying a tract of Silurian rocks (Lower Old Red Sandstone). The 
arenaceous Carboniferous rocks to the eastward were mapped by 
Griffith as Calp, but of late years they have been said to belong 
to the Lower Coal Measures. No good proofs, however, in favour © 
of this change of classification seem to be forthcoming, while they 
are very similar to the Calp rocks north of the Tyronr CoaL-FIELD. 

At Lisbellaw, 8.H. of Upper Lough Erne, is a small exposure 
of Ordovicians ; while to the north and north-east of the same lake 
are portions of the adjoining tracts of Metamorphic rocks, which 
may be either Cambrians or Ordovicians. 

Except in connexion with the clay-iron-stone in the Coal 
Measures, this county is absent from Griffith’s list ; but since that 
was published, copper, iron, and molybdenite have been found at 
Castle Caldwell in the Metamorphic rocks. No mineral lodes 
have been found in the Carboniferous limestones or in the Silu- 
rians; this, however, may be due to: the great head of drift, or 
bog, over those areas. 

During the years 1620 to 1641 extensive mining and milling 
of iron was in progress, the principal works belonging to Sir 
J. Dunbar and Sip L. Bleverhasset (Blennerhasset). In latter 
years the iron appears to have been also mined and smelted until 
the forests were exhausted. 


280 Scientific Proceedings, Royal Dublin Society. 


GALWAY. 


Except the north-western portion of the county (Yar or West 
Connaught}, the rocks are principally Carboniferous Limestones, 
with subordinate sandstones and shales; but through these come 
up detached exposures of Ordovicians. Yar Connaught is occupied 
nearly altogether by metamorphosed Ordovicians and Cambrians, 
with their associated Granytes and Granitic rocks ; but on them, to 
the north, is a tract of Silurians. 

As it has been stated that some of the Yar Connaught rocks 
are Laurentians, it may be pointed out that when Murchison 
some years ago suggested that the oldest rocks of the county, 
those of the Bennabeola Hills, were of that age, he afterwards 
found reasons to withdraw his suggestion ; while the rocks now 
stated to be of that age carry fossils of Llandeilo types. 

In the Carboniferous Limestones some good and rich silver-lead 
accumulations have been worked; but unfortunately, as at Caher- 
glassan, near Gort, and elsewhere, on account of the cavernous 
nature of the rock, and the low altitude of the county, they can- 
not be profitably worked, the influx of water being too great. 
Some of the lead mines in the south-east of the county are 
supposed to be prehistoric, not having been worked since 1640, 
and probably not for centuries previous. 

In the Metamorphic and Granitic rocks are many lodes and 
indications of copper, sulphur ores, lead, and zinc; some very 
rich bunches having been already extracted. All the mining 
operations in the area have been on a small scale, proving the 
lodes at the surfacé, but not in depth; and from what is now 
known it would appear as if at some future time it might be the 
seat of large and remunerative mining operations, more es- 
pecially if reducing works were erected in the county, as, dn 
ageount of the great preponderance of sulphur ores (pyrite and 
pyrhotite), the ores in their raw state will not bear the expense of 
long carriage. 

At intervals between 1620 to 1750 iron was extensively 
smelted and milled in different places along Lough Derg, the 
dast furnace alight being that of Woodford, belonging to the 
Burkes of Marble Hill. In these furnaces the bog-iron-ore was 


Kinanan—On Irish Metal Mining. 281 


in part used ; but it was mixed with clay-iron-stone from counties 
Limerick and Clare, and limonite from Tomgraney, Co. Clare, 
brought up the Shannon in boats; the furnace and mills being 
erected hereabouts, on account of the vast forests in the neighbour- 
ing hills. 

There were also furnaces in places on the western coast: to 
these foreign ore was brought by sea, to be mixed with the native 
bog-iron-ore. 

The native sulphur found in the limestone at Oughterard 
seems to be long known, as the ancient name of the river is 
Owenriff, anglice Brimstone River. Blue fluor spar occurs at Ju- 
verin, west of Spiddal, while pale-bluish, greenish, and yellowish 
translucent varieties were found at Glengowla, near Oughterard. 


KERRY. 


In the south-west of the county, including the promontory of 
Jeveragh and the Killarney hills, are Devonians and Silurians 
similar to those of West Cork (see page 273), having on them, 
alongside the bay called Kenmare River, Yellow Sandstone and 
Carboniferous Slate; but eastward, at Kenmare, these are replaced 
by cleaved Limestone and Lower Limestone Shale, or the transition 
rocks between those of the West Cork types and those of the 
Central plain types (West Cork rock, p. 273). 

In the Dingle promontory there are Si/wrians and Ordovicians. 
To the northward and eastward (Slieve Mish) these are capped 
unconformably by rocks that represent the upper portions of the 
Devonian rocks of West Cork; while further northward in the 
Kerry Head promontory are similar rocks. The Kerry Head 
and Slieve Mish Devonians he conformable under the Carboniferous 
Sandstone Shales and Limestones of the low country to the eastward, 
the latter being capped by Coal Measures, a part of the extensive 
West Munster Coat-FIELp. 

As has been mentioned, in the resumé on Cork, the coals 
known in the Kerry portion of this field are of little value, while 
there are small prospects of better being found. In general these 
are more or less culm, or thin. Not much clay-iron-stone is 
_xecorded ; some, however, was raised in old times. 


282 Scientifie Proceedings, Royal Dublin Society. 


In the Carboniferous Limestone silver-lead and silver occur im 
various places; but, except in the Killarney district, the lodes or 
strings in general have not been very large. The Killarney lodes 
have been long known, having been worked in the eleventh . 
century. Nemius, writing at the time, states: copper, lead, tin, 
and iron were found there. Smith, in his history, also says he- 
found some tin-ore ; but in subsequent time it has been unknown, 
and never was worked. 

When working the copper mine at Muckross, in 1794, M. 
Raspe discovered cobalt, bloom and grey cobalt. After the dis-. 
covery little remained to be utilized, as all the accumulation, 
except about twenty tons, had been run into the lake as rubbish. 
The small portion saved had been surreptitiously carried away by 
a miner who recognized it as Erythrite (Hane). 

Near Castleisland there is a slate, called Lapis Hibernicus,. 
which was formerly worked and carted to Tralee, to be used in 
the manufacture of copperas. This industry had, however, to be 
abandoned, on account of the difficulty and expense of the car- 
riage of the copperas to the nearest market. 

In the seventeenth century, on account of the extensive forests, 
various iron furnaces were erected in places along the coast, to- 
which iron-ore was imported. The Karl of Cork, however, seems 
to have smelted native ore near the south of the country, while 
there are also the ruins of furnaces and works at Killarney. 

Lewis records copper pyrites as having been found prior to- 
1837 in Glancrought. 

A vein of amethyst of a very beautiful colour, near Kerry 
Head, was formerly used for jewellery. 


KOLDARE. 


This county is situated near the eastern margin of the great 
central area of Carboniferous Limestones, which, to the eastward, 
except south of Celbridge, seem to lie direct on the Ordovicians.. 
South of Celbridge to the east of Ballitore, and in connexion with 
the Chair of Kildare range of hills are small tracts of Lower Car- 
boniferous Sandstone, with an exposure of Ordovicians in the last. 
At the eastern margin of the county, intruding into the Ordo- 
vicians, there is Granyte. 


KinaHan—On Irish Metal Mining. 283- 


The county in general is covered by drift, or bog, and only in 
a few places have mineral veins been discovered. Lead was mined 
at Wheatfield, near Celbridge, in 1828; while Lewis records 
copper and iron as having been found in the Ordovician rocks. 
of Dunmurry, near Kildare, in 1786. 

No gold is now found in the county; yet tradition has it, that 
ancient Placers were worked somewhere near Ballymore-Eustace. 
At one time the Upper Liffey, above Poulaphuca, must have run 
northward along the flats at the mearing of Wicklow and Kildare 
to join into the Slaney at Baltinglass; and it is possible that 
somewhere in these ancient river-gravels the traditional Placers. 
were situated. 

In the counties Dublin, Wicklow, and Wexford, to the east- 
ward of the Leinster Granyte range, in the Metamorphic Ordo- 
Vicians, are mineral veins; while, as pointed out by previous 
writers, none have been found in the similar rocks westward of 
the Granyte, except the iron vein in Glenasplinkeen, Co. Wicklow. 
This possibly may be due to the deep limestone gravel, extending, 
from the plain up unto the Granyte, often to the height of 400 
feet, and in places to 500 feet or more, thus preventing the Meta- 
morphic rocks being properly seen or examined; as eastward of 
the range, where the mineral veins have been found, these drifts 
varely occur above the 250 feet contour line. Similarly in the Co. 
Wexford, to the eastward of the range, where the rocks are more 
blinded by this drift, the mineral localities known, are fewer than 
in the Co. Wicklow. 


KULKENNY.’ 


To the south-east of the county there is an area of Ordovicians, 
having in it intrudes of Granyte ; while to the west, and extend- 
ing into the Co. Tipperary, is a small exposure of Ordovicians. 
Margining the Ordovicians is Lower Carboniferous Sandstone, and 
on it Carboniferous Limestone ; while to the northward, surmounting 
all, are Coal Measures, a part of the Lurnsrer Coat-F1ELD. 

As the anthracyte was first worked in Kilkenny by the English, 
the general name of “ Kilkenny coal” has been given to this 
Trish coal; we may therefore here give a reswmeé of the history of 
the field. 


284 Scientific Proceedings, Royal Dublin Society. 


In old times iron-ore was raised and wrought in the LzinsTer 
CoAL-FIELD, but when, and by whom, does not appear to be now 
known, the first authentic records being those of the English, 
between 1615 and 1641. At this time Christopher Wandesford 
had extensive mines and works, principally in Idrone, Co. Carlow, 
where, besides other things, he cast and wrought ordnance. Sir 
Charles Coote had large workings in the Queen’s Co., his furnaces 
and mills being at Mountrath; while in the same county Lord 
Londonderry had a furnace and mills at Ballynakill, and Sergeant 
Piggoth at Dysert.’. All these appear to have been burnt down in 
1641, but were afterwards rebuilt, and the manufacture was 
carried on as long as the forest lasted. It is said that after 1728 
attempts had been made to smelt the iron-ore with the anthra- 
-eyte, but none of them were successful. 

According to Boate, coal was first discovered near Wandesford’s 
furnace in Idrone, Co. Carlow, between 1630 and’40, while the miners 
were raising the clay-iron-stone. He states that the county people 
worked it along the edge, or basset, for their own use, but 
suggests that when the forests were exhausted it might come in 
handy. But the first pit opened was not till 1728, either in 
Carlow or the adjoining portion of Kilkenny. Here the coal was 
found to be bad, and other pits were sunk in Coolbaun Hill, 
near Castlecomer, where three seams were found and successfully 
worked. Besides these three coals, which are only found in Cool- 
baun Hill, others that have been found profitable to work are 
the Old Colliery Three-foot Coal, the Rushes or Modubeagh Coal, and 
-a curious channel called the Jarrow Coal, which occurs in connexion 
with the Old One-foot Coal. 

The Old Colliery Three-foot is practically worked out; what 
_ little that remains would scarcely pay for the getting. The One- 
foot Coal, which is often only five or six inches high, does not pay 
for working ; but the Jarrow Channel, in connexion with it, has 
been very profitable. Unfortunately it was only of limited 
-extent, occurring in a semicircle to the north of Coolbavn Hill, 
and in a nearly straight line to the south of it. Of this coal 
there now remains about a mile and a-half in length to the north 
of Coolbaun, and about two miles to the south. According to 


1See Dysert, King’s Co., p. 286. 


Kinanan—On Irish Metal Mining. 285- 


Mr. Dobbs’ estimate it is profitable for a width of 400 yards, and 
is of an average height of three feet. If every cubic yard is equal 
to a ton of coal, we have in these portions of the channel about 
2,000,000 tons of unwrought coal. There are outlying portions 
of this channel still unworked, which may contain something 
between 250,000 and 500,000 tons of coal. If the highest figure 
is taken, which is probably above the estimate, there will be less 
than 3,006,000 of tons of unwrought coal. 

The only other coal available is the Mobubeagh Coal. This,. 
under the name of Towlerton Coal, Mr. Hull estimates as pro- 
fitable, about 10,000,000 tons. This estimate, however, is evidently 
excessive, the coal being taken as two feet high, while it rarely 
exceeds one foot nine inches, and in places has thined to nearly 
half that height. A foot coal would be valueless, as, on account 
of its great depth from the surface (about 216 yards below the Old 
Three-foot Coal), the cost of “ getting” would exceed the value of 
the coal. Whether it is of any value cannot be known until a 
bore-hole is put down somewhere near the centre of the colliery. 
At no time was there much profitable coal in the field. It began 
to be mined about a century and a-half ago (1728), and now it is 
nearly exhausted. 

The anthracite is of four classes—stone coal; kennel, or hard 
compact shaly coal; culm, or friable flaky coal; and kelve, or shaly 
earthy, impure coal. 

Very few mineral veins have been found in the county. In 
the valley of the Nore was the silver mine called Argetros, 
which, according to the Annals, was worked a.m. 38817. In this 
valley silver and lead have been found at Ballygallon, near 
Inistioge, and Knockadrian, near Knocktopher: at the latter place,. 
recently, they were worked for some years successfully. 


Kane’s Country. 


The majority of the rocks within the limits of this very irregu- 
lar county belong to the Carboniferous Limestone. In these are a few 
exposures of Sandstone, and to the north of Phillipstown an intrude 
of Whinstone. At the south-east is a portion of Sheve Bloom, 
wherein is found an exposure of Ordovicians flanked by Carboniferous: 
Sandstones. 


286 Scientific Proceedings, Royal Dublin Society. 


As the county is for the most part enveloped in drift or bog, 
only a few mineral veins have been found, although it is possible | 
more may exist, chalybeate springs being so numerous ; some of the 
latter, however, are evidently due to the decomposition of the 
pyrites in the Calp. A lead mine was for a time worked at 
Edenderry. 

Boate mentions that prior to 1640, Sergeant-Major Pigott 
mined and smelted iron ore (imonite?) at “ Dysert lands” in “the 
King’s County,’’ and from his account the mining works must 
have been extensive. At the same time Sir Adam Loftus, Viscount 
of Ely, had works near Mountmellick, but where he procured the 
ore is not stated. 

The mearings of the King’s and Queen’s counties have been 
changed at different times, and portions that were in the King’s 
County in Boate’s time may now be in the Queen’s: the place, 
Dysert Land, has not been localized, and possibly it may be the 
iron mines at Desert in the Queen’s County (Sheets 13 and 18), 
now the property of Lord Carew. 


LEITRIM. 


Nearly the whole of Leitrim is occupied by Carboniferous rocks, 
including a portion of the Connaucur Coat-FieLp. At Manor- 
hamilton, coming in from the Co. Sligo, is a narrow exposure of 
Metamorphic rocks, probably of Cambrian age, but possibly older. 
At the south-east of the county is the marginal portion of a tract 
of Ordovicians ; while a little exposure of similar rocks, surrounded 
by Carboniferous Sandstone, appears to the south-east, close to’ the 
Shannon. 

The coals and the working of iron in the Connaueur Ooat- 
FIELD is given in the description of the Co. Cavan, page 267. Be- 
sides the clay-iron-stone of the Coal Measures and the bog-iron-ore 
limonite was also mined and smelted in the seventeenth and 
eighteenth centuries procured from the Ordovicians at Gortinee, 
south-east of Drumsna near the Shannon. In late years, between 
1860 and 1880, some ore was also raised here, and exported to 
England. 

In the Metamorphic Cambrians (?) at Gortnaskeagh, Pollboy, 


Kinanan—On Irish Metal Mining. 287 


and Shanvans, N. W. of Manorhamilton, copper was mined prior 
to 184,5 while lead was raised in the adjoining mine of Twigspark. 
The lodes at Pollboy and Shanvans, although in the Metamorphic 
rocks appear to have been of Carboniferous or of part Carboniferous 
age; as associated with the ores, “‘ copper with a little lead,” there 
was Dolomyte. From the position of the lodes it may be suggested 
that they are “contact lodes,” at the junction of the Carboniferous 
and the Metamorphic rocks, they belonging to the same class of 
lodes as the great lode at Silvermines, Co. Tipperary. Along the 
line of contact there ought to be other deposits not yet discovered. 

The old attals and shafts prove early mining operations; but 
the date at which the lode wsa first worked seems to be now un- 
known. 


LIMERICK. 


To the south-east, coming in from the Co. Tipperary (a part of 
Sleve Phelim) are Ordovician rocks, capped by Carboniferous Sand- 
stones (Upper Old Red) ; while the rest of the area is occupied by 
limestone or other Carboniferous rocks. ‘'T'o the west there are Coal 
Measwres, a part of the West Munster Coat-FieLp; while between 
these hills and those of Slieve Phelim the plain is principally 
occupied by the Carboniferous Limestone, but having associated with 
it beds and intrudes of Volcanic rocks and a few outlying Sandstone 
exposures. 

At Ballybrood there is a small patch of Coal Measure sur- 

rounded by Volcanic rocks; the latter possibly represent the ruined 
walls of a Carboniferous Volcano. 
As has been mentioned in the description of the Co. Cork, the 
coals in the Co. Limerick are thin: formerly they were worked at 
or near their outcrop; but no deep trials has been satisfactory, the 
coals proved, not to be sufficient in quantity or quality to pay for 
deep workings. Iron ore, in the seventeenth and early part of the 
eighteenth centuries seems to have been extensively worked, especi- 
ally in the vicinity of the Shannon ; partly to supply the furnaces 
near Glin and Loughill, and in part to be sent by boat up the 
Shannon for the use of the furnaces and mills in the vicinity of 
Lough Derg. 

In the Co. Limerick, more than elsewhere in Ireland, the 


288 Scientific Proceedings, Royal Dublin Society. 


Carboniferous Limestone is divided into Lower Shaly Limestone 
Fenistella Limestone, and Calp; the latter in part of the Burren type. 
Above and below the Fenestella Limestone are well-marked cherty 
zones, and below both of these, especially the first, mineral accu- 
mulations occur. Some rich pockets and shoots were found and 
worked out prior to 1850; while since then lead has been found 
in a few places, but the extent of the deposits have not been proved. 
According to Lewis (1837), “there are indications of a valuable. 
mineral ore near Tory Hill;”’ no trials, however, seem to have been 
made thereabouts. 

In the Carboniferous Sandstone and the Ordovicians a few small 
veins with copper have been found, but not sufficient to make 


mines. 
Large amethysts and cairngorms are found near Shanid Castle 


and Foynes. 


LonDONDERRY. 


At the east of the county, extending in from the Co. Antrim, 
there is a tract of Hocene(?) Doleryte, which overlies the Cretaceous, 
Jurassic, Triassic, and Carboniferous rocks. To the northward the 
rocks of these older formations, except the Carboniferous, form 
more or less narrow, continuous, successive strips, margining the 
Doleryte; but southward the latter more or less overlaps them 
all. ‘The Carboniferous rocks are for the most part of the North of 
Ireland “Calp type;” but in places there are good limestones, 
and in others sandstones and conglomerates of the Lower Carbonife- 
yous types. The Carboniferous rocks were evidently accumulated 
in valleys in the older Metamorphic rocks, which occupy the rest 
_of the area, and therefrom into the counties of Donegal and Tyrone. 
They are probably of Ordovician age. With the Metamorphic 
rocks are associated intrudes of Granyte. 

In the Hocene(?) Diorytes, as in the Co. Antrim, there are 
beds of iron-ore; but not as numerous or valuable. In the Calp 
shales near Draperstown are clay-iron-stone bands and nodules: 
worked by Rennie, and smelted in the valley of the Moyola, prior 
to 1640. This Iron Master also mined hematite and limonite in 
the Ordovician and Granyte rocks. Between 1860 and 1870 
openings were made on these lodes, but no permanent work done, 


Kinanan—On Irish Metal Mining. 289 


on account of the depression in the iron trade. In the Ordovician 
rocks the iron in general, is associated with manganese. 

Traces of copper and sulphur ores have been found in the rocks 
(Ordovicians) of the Ballynascreen mountains, but none of the veins 
have been opened up. 

Prior to 1641 Boate records gold as occurring in the gravels of 
the Moyola river, but since then none seems to have been found. 

There is a possibility that Coal Measures, with profitable coals 
may yet be found under the Trias at the south-east of the county.— 
See Ulster Coal-field, Co. Tyrone, p. 298. 

Portlock calls attention to large beds of ochre at Aughlish and 
Tamnagh, in the parish of Banagher, and Glenviggan in the 
parish of Ballinascreen, as suitable for making red paint, similar 
to that employed in Sweden to paint and preserve the wooden 
houses. The surface deposits, or bog-iron-ore, is in places at 
present exported, to be used in the purification of gas. 


LonGForp. 


In the north-east of the county, coming in from the Co. Cavan, 
is the margin ofa tract of Ordovician rocks. The rest of the area 
is principally Carboniferous Limestones, with, to the north, a margin 
of Carboniferous Sandstones and Shales. In a few places are small 
protrudes of Ordovicians, associated with Carboniferous Sandstones. 

The localities for minerals are few (see Lists); the most im- 
portant are the iron lodes at Cleenragh and HEnaghan, near Lough 
Gowna. ‘These were worked in the seventeenth century, and also 
prior to 1870, by Dr. Ritchie of Belfast. In the earlier times 
they seem to have been smelted in the county, but Ritchie ex- 

ported them, carrying them across the lake in boats, and thence 
by rail to the port. Suilver-lead is recorded as occurring in the 
Carboniferous Limestones at Longford. 


Lovutu. 


The major portion of this area is occupied by Ordovician rocks, 
on which, to the south, west, north, and north-east, are small 


tracts of Carboniferous Limestones, with its Sandstones and Shales. 
SCIEN. PROC. R.D.S.VOL. V. PT. IV. x 


290 Scientific Proceedings, Royal Dublin Society. 


To the north-east, forming a hilly country south-west of Carling- 
ford Lough, are peculiar Granitic and other Intrusive rocks. 

In different places in the Ordovicians, veins of lead and copper 
have been found, and at Jonesborough antimony; while mines 
were worked about the year 1840 at Salterstown, and near Clogher 
At the junctions of the Granyte and the Ordovicians traces of lead. 
occur in different places. 

Near Clogher Head there is a poor iron-ore, and in different 
places in the hills are the ruins of old iron works: the ore for the 
latter may have been imported. 


Mayo. 


In this county about half the area is occupied by Metamorphic 
rocks (probably Ordovicians and Cambrians) and their associated. 
Granytes. Some of the Metamorphic rocks are said to be Lau- 
rentians, but lithologically, and apparently petrologically, the 
younger rocks of the series are similar to the Co. Galway rocks 
that carry fossils of Llandeilo types. On them, to the south- 
west, and extending into the Co. Galway, are St/urians ; while 
smaller tracts of the same age occur south, west, north, and north- 
east of Clew Bay, the last in Croagh Moyle, being the largest. 
The rest of the area is occupied by Carboniferous rocks, Coal 
Measures, &e. 

A valueless coal occurs in the Coal Measure, but associated, 
with it is clay-iron-stone, that was worked to be smelted in 
Gildeas’ furnace at Port Royal. 

Limonite, or hematite, was mined in Cross and Tallaghan, 
barony of Hrris, and in the Cloonaghan and Deel river valleys, 
“barony of Tirawley. Formerly Sir George Shaen smelted and 
milled iron near the Mullet; while a little later Rutledge had 
works on the Deel. Both these Iron Masters had to discontinue 
their works for want of fuel when the woods were exhausted. 

At Port Royal, near Ballinrobe, the Gildeas, in Charles II.’s 
time, were given a grant of land, in which they mined and 
smelted iron. The ore principally used was bog-iron-ore, mixed 
with the clay-iron-stone raised near Balla, some miles to the 
north; while tradition has it that they also procured limonite 


Kinanan—On Irish Metal Mining. 291 


from the neighbouring Silurian and Ordovician hills. The furnace 
at Port Royal is supposed to have been put out at the end of the 
eighteenth century, being one of the last wood charcoal furnaces 
alight, 

Very few other mineral veins are recorded, those named being 
ores of copper, sulphur, and lead. A. silver-lead mine was 
formerly worked at Sheefry, between Westport and Killary 
Bay ; while trials were made on coppery lodes in Corraun Achill. 
On account of the great area of the county, and the favourable 
nature of the rocks, in places, it would appear possible, if proper 
search was made, that some profitable lodes might be found. 
Lewis states “rich deposits of manganese have been found in the 
neighbourhood of Westport.” 


Meatu. 


To the south-east of this county, near Balbriggan, also north 
of the valley of the Boyne, there are tracts of Ordovicians; while 
the rest of the area is nearly solely occupied by Carboniferous 
Limestones, principally of the “Calp type.” On it, in places, are 
small patches of Coal Measure Shales ; while to the north, coming 
in from the county Monaghan, is the south end of a small tract of 
Trias, associated with a patch of Coal Measures. 

In the Trias there is gypsum, formerly mined (Monaghan, 
page 252); and in the, adjoining Coal Measures there is a thin 
coal, that was worked a little, along its outcrop. Although pro- 
fitable copper lodes are not usually found in the Irish Carbonife- 
rous Limestone, yet about 1800 copper-ore was raised at three 
places near Walterstown; and subsequently at Beaupark, near 
Slane. Also in the Carboniferous Limestone, lead was worked at 
Athboy ; while in the Ordovicians at Clogher, near Ardcath, there 
is a lead mine, considered by Griffith to be very ancient. Lewis 
reports a “rich copper lode,” near the banks of the Boyne, 
“unworkable profitably on account of the influx of water.” 


292 Scientific Proceedings, Royal Dublin Society. 


MonaGHAN. 


Both to the north and south are tracts of Carboniferous rocks ; 
while on the latter is a small outlyer of Trias, margined eastward 
by Coal Measures. Nearly all the rest of the area is occupied by 
Ordovicians. 

In the Trias to the 8S. W. of Carrickmacross there is a consider- 
able deposit of gypsum, some time since mined and manufactured 
into “Plaster of Paris” at Knocknacran, until the works were 
burned down about the year 1869. In the Coal Measure is a 
valueless coal, while other valueless coals occur to the north of the 
county, near Slievebeagh. The tumblers of limonite found S.H. 
of Kingscourt are mentioned in the “ Iron List,” Part I. 

Veins of lead-ore have been found in numerous places, those 
at Lisglassan and Tullybuck being associated with antimony ; 
while in other places there was barytes, or a little zinc. Lewis 
states that in the “ Creina Hills” there had been works for reducing 
lead; but they were abandoned some years prior to 1838. 

The majority of the mines recorded in this county seem to 
have been worked between 1830 and 1855, but some before these 
dates. The lodes in this county appear in general to have been 
small; but, on account of their number, also that others occur in 
the neighbouring counties of Cavan, Armagh, and Louth, it 
would appear that mining might be remunerative when trade 
revives ; especially if reducing works, calculated to utilize all the 
mineral products were erected at a good centre. 


QuEEN’s CounryY. 


Slieve Bloom, which lies to the north-west of the county, has 
a nucleus of Ordovicians, the slopes of these’ hills being Carbonife- 
rous Sandstones and Shales. The rest of the area is occupied by 
Carboniferous Limestones and Coal Measures, the latter being a 
portion of the Leinster CoAL-FIELD. 

The iron ore and coals have already been described with those 
of the Co. ‘Kilkenny (page 283). In this county coal was first 


-Kinanan—On Irish Metal Mining. 293 


discovered at Gale and Oullenagh Hills while working the iron- 
ores. The “Gale Hill coal” is interesting, as one of the first 
discovered ; but is also important because a little below it, is 
the great horizon where the iron-ore was worked in the seven- 
teenth century. For no apparent reason, except it may be to 
introduce a new set of names for the coals, this coal has been 
ignored in the second “Geological Survey Memoir,”’ published in 
1881 (Parts of sheets, 127, 128, 136, 187, &e., by Messrs. Hull and 
Hardman); although the same coal, under a new name, is recog- 
nized in other places. After Wandesford, in 1728, commenced 
to mine in the Oo. Kilkenny, the Grand Canal Company and 
others put down a number of bore-holes in this county, thereby 
proving the extension of the Kilkenny coals. These coals, how- 
ever, are now nearly worked out (page 285). 

The iron mining, smelting, and working (List of Iron Masters, 
page 259) were considerable, both before and after 1641, and only 
ceased when the forests were exhausted. At Dysert, near Mary- 
borough, the property of Lord Carew, are limonite veins, formerly 
extensively worked; there, as previously suggested (page 286), 
may be the mines mentioned by Boate as situated in the King’s 
Co., and worked by Sergeant Pigott. 

Traces of copper and lead have been found in the Ordovicians 
of Slieve Bloom, but the localities are not recorded. 


Roscommon. 


In the Curlew Mountains, at the north of the county, are 
reddish and greenish Sélurians, with their associated felspathic — 
Jixotic rocks, the Silurians being margined by Lower Carboniferous 
Sandstones and Shales. To the east, near the Shannon, in Slieve 
Baun, are small exposures of Ordovicians, also margined by similar 
rocks; while the latter also form small tracts to the W.S.W. of 
Roscommon, and the N.E. of Castlereagh. Most of the rest of 
the area is occupied by Carboniferous Limestones, they having on 
them at Lough Allen—Ooal Measures—a portion of the ConnauGHr 
CoAL-FIELD. 

The coals and clay-iron-stone appear in the description of the 
Co. Cavan (page 267). No other metallic ores are recorded. In 


294 Scientific Proceedings, Royal Dublin Society. 


places, however, there appear to be indications of lodes, but the 
great head of drift, or bog, prevents them from being easily 
found. 


SLIGo. 


The Carboniferous Limestones occupy the principal portion of 
this area, having on them to the south-east a small but rich tract of 
Coal Measures, part of the Connaveut CoaL-FIELD. Crossing the 
county obliquely is the Ox Mountain range, the rocks being meta- 
morphic, flanked in places by Lower Carboniferous Sandstone: these 
Metamorphic rocks are probably of Cambrian and Ordovician ages, 
although, from their lithological characters solely, they are stated 
by Professor Hull to be Laurentians; but the petrological evidence 
seems to be conclusive against such an age. At the south margin 
of the county are small exposures of the Curlew Mourttain Silu- 
rians. 

The coals and clay-iron-stone of the ConnaucHt CoAL-FIELD 

are mentioned in the history of the Co. Cavan. Other iron-ores, 
however, seem to have been raised, and were smelted at Ballin- 
togher “and at the base of the Ox Mountains.” Lewis also 
states, when writing in 1837, that “near Screevenamuck are 
excavations, where the ore was raised as long as timber could be 
procured for smelting it, the last furnace having been put out 
in 1768.” At Ballynakill, between Ballintogher and Rivers- 
town, are the ruins of extensive iron works; while limonite 
appears to have been mined in the adjoining Carboniferous Lime- 
stone. 
_ Lead has been worked in the Metamorphic rocks, and silver- 
lead in the Carboniferous Limestones near Ballysodare; while lead, 
copper, and barytes have been found and worked in the King’s 
Mountain. The Abbeytown mine, near Ballysodare, has been 
worked on and off during the last hundred years. In Glen- 
carberry, King’s Mountain, unsuccessful attempts to work pro- 
fitably the large accumulation of barytes were made between 
1870 and 1880. 

Well-coloured and well-shaped large amethysts have been 
procured in the neighbourhood of Ballymote. 


Kinanan—On Irish Metal Mining. 295 


TIPPERARY. 


_ The Killenautle, or Hast Munster Coat-Fiexp, lies to the east 
of this county, it being joined to the Kilkenny field by a tract of 
Lower Coal Measures—while outlying small patches of the latter 
are found N. E. and S. W. of Fethard, N. W. of Clonmel, at the 
Bock of Cashel, and in Slievenamuck, S.W. of Tipperary. ‘To 
the 8. E. of the area in Slievenaman are Ordovicians, flanked by 
Lower Carboniferous Sandstone; to the 8. W., in Knockmealdon, 
are rocks that possibly may be the eastern extension of the Co. 
Cork, Devonian and Silurians; to the west, in the Galtees and Slieve- 
namuck, are small exposures of Ordovicians, margined by Lower Car- 
boniferous Sandstone; and to the N. W., in the Arra Mountains, 
and Slieve Phelim, are similar groups of rocks, similarly related ; 
while most of the low country is occupied by the Carboniferous 
Limestones. 

_ Between 1780 and 1740, coal was searched for and found by 
the Langleys in the Coalbrook Colliery, but some forty or fifty 
years seem to have elapsed before it was worked by the Goings in 
Farl’s Hill; and elsewhere by the Mining Company of Ireland— 
the collieries not being well developed till after 1825. 

The profitable coals were—Surface, Parkenaclea, Clashacona, 
Main, and Gilengoola. All the beds above the Main coal were solely 
found in Earl’s Hill, where the measures are thickest, while the 
Main coal, besides here, was only found in some detached basins. 
All the profitable portions of these coals, except the Glengoola 
beds, and small tracts of limited extent of others, seem now to be 
worked out. | 

Associated with the Glengoola coal in Coalbrook and elsewhere 
are some seams of rich clay-iron-stone, but I can find no records 
of these having been mined or smelted. Other iron ore, however, 
was raised in the older rocks, and smelted at, Gortnahalla, in the 
valley of the Clodiagh, to the S. W. of Borrisoleagh. Some ore 1s 
also said to have been raised and smelted near Roscrea: these 
latter works may, however, have been in the King’s County. 

At Gleninchinaveigh, near Upper Cross, there is a vein con- 
taining anthracite and graphite, four feet wide at surface. This, 
in 1857, was sunk on for a depth of ten fathoms, but the walls 


296 Scientific Proceedings, Royal Dublin Society. 


closed in and cut it out; it was also driven on for five or six 
fathoms. 

Lead, copper, and other minerals, as given in the Lists, Part L., 
have been found and worked in different places; there having been 
prehistoric workings on the silver-lead at Garrane, near Tooma- 
vara; at Silvermines, near Nenagh; and at Garrykennedy, on 
Lough Derg. 

Of the mines, the most important and interesting are those on 
the great Mineral Channel at Silvermines. Boate states, in rather 
disparaging terms, that this mine was first discovered by the 
English about the year 1600; but the researches made during the 
present century, and the statements in the Annals, would suggest 
it had previously been worked by the ancient Irish, as were also 
the mines to the westward, at Garrykennedy; and to the eastward, 
at Garrane. 

From Boate we learn that at first, Silvermine was supposed to 
be a lead mine, but afterwards they found it contained “ three 
pounds of silver to the ton of lead;”’ also ‘‘some quicksilver.” As 
far as I can learn no trace of the latter has been detected in late 
years. Under the King the mine was farmed by Sir William 
Russel, Sir Basil Brook, and Sir George Hamilton; but the mine 
was destroyed, and the works burnt down in 1641, by Hugh 
O’Kennedy, brother to John Mac Dermott O’ Kennedy, who ought 
to have been its legitimate owner. After the troubled times the 
English company seem to have again worked it till their lease 
expired, about 1730: subsequent to this it was worked by different 
companies, who found and opened up new lodes, till eventually it 
came into the hands of a Mr. Hudson, who at the beginning of 
the present century sold his interest to the General Mining Com- 
pany of Ireland; these carried on active operations till about 1870. 

After the time of the English company various lodes were dis- 
covered in the county to the westward; some of them contain- 
ing argentifeyous copper and lead, others argentiferous lead—the 
latter giving eighty ounces of silver to the ton. In 1858, Captain © 
Thomas King, while exploring the ancient lead and silver mines, 
discovered electric calimine ; it evidently being due to the chemical 
decomposition of the blende that had been run as attals or wastes 
into the ancient levels; this for some time was profitably worked. 

The Silvermines Mineral Channel is interesting, being a ‘‘con- 


Kinanan—On Irish Metal Mining. 297 


tact lode”’ at the junction of the Carboniferous and Ordovician 
rocks, extending for at least thirty miles; from Gallow’s Hill, 
Co. Clare, to the westward; to Toomavara on the eastward. Along 
this line mines have been worked at Garran, near Toomavara, and 
at Silvermines; while indications have been detected in the Co. 
Clare, which seem to suggest that in other places along this ‘‘con- 
tact break” profitable lodes may yet be discovered. 

At Lackamore, copper was raised in old times, while an un- 
successful attempt to work the lodes- was made between 1800 and 
1810; they were subsequently opened on by the Mining Company, 
who broke some very rich ore; but as the quantity was small, they 
also abandoned them. The last adventurers were the Messrs. 
‘Taylors of London, who raised some ore up to 1859. Lewis 
mentions a lode found in the townlands of Cappaghwhite, 
Ballysinode, and Gortdrum, which contains rich copper in bunches, 
and. was leased to the Mining Company, who, in 1826, spent some 
money at Gortdrum, but apparently without any return. 

At Hollyford there are two parallel lodes cut off by a cross 
course. On the eastern, or Ballycolein lode, there was an ancient 
mine; as about 1850, at the cross course, were found ‘“ Old Mens ”’ 
workings and tools. In 1858 the western lode was worked under 
Captain John Pascoe, while subsequently the mines got into the 
hands of an English bogus company, who became bankrupts. 


TYRONE. 


The geology of Tyrone is very interesting. To the north, 
coming in from Londonderry and Donegal, are Metamorphic 
rocks, which belong to two distinct geological periods, probably 
Ordovicians and Cambrians—south of the latter, at Pomeroy, are 
unaltered Ordovicians. Dr. Hincks has suggested that the older 
rocks may be Laurentians, but solely on account of their litho- 
logical characters ; they are evidently of the same age as the older 
rocks in Donegal. The Pomeroy Ordovicians are overlaid by 
Silurians of the Fermanagh type, and those to the south and east 
by Carboniferous Sandstones, Shales, and Limestones; and on the 
latter, to the north-eastward of Dungannon, are the Coal Measures 
of the Unsrer CoaL-FIELDs. Margining, and on the Coal Measure, 


298 Scientific Proceedings, Royal Dublin Society. 


are Trias rocks ; and in places Cretaceous rocks (White Limestone),. 
Eocene (?) Doleryte, and the “Lough Neagh beds”—the age of 
the last being still disputed. 

Associated with the Metamorphic rocks are Granitic rocks of 
three or more distinct ages. In the westward and north-west- 
ward there are other tracts of Carboniferous rocks. 

In the south of the county the Carboniferous rocks have well 
marked divisions, having a central zone of sandstones and shales 
(Calp), while to the westward and north-westward they are more 
mixed up. ‘The Calp of Ulster is more or less similar to the Coal 
Measure sandstones and shales, having in it, in the Co. Derry, 
workable beds of clay-iron-stone ; and at Ballycastle, Co. Antrim, 
workable coals. By some observers the rocks of these two distinct 
groups have been confounded together. This is a matter of im- 
portance, as this incorrect mapping has led persons to make 
unsuccessful trials for coal in the Calp. 

In the Silurian are the characteristic felspathic bedded rocks. 
(eurytes) ; while associated with the Trias, in the north of the 
county, are dolomytes, said to contain fossils of Permian types. 

In the “Lough Neagh beds” are seams of lignite, but too 
insignificant to be valuable; silicious pieces of the lignite are 
known as “ Lough Neagh hones.” 

In the Trias at Croagh, also elsewhere, gypsum has been 
found, but not in sufficient quantity to be economically worked. 

The Tyrone coals are seemingly of great importance. As has 
already been mentioned, the coals in Leinster and Munster are in 
the Upper Measures, and those in the Connaught field in the 
Middle Measures; but in Tyrone they are found both in the 
Middle and Upper Measures. Furthermore, the Ulster are gas 
coals, while those of Leinster and Munster are anthracates; those 
of the Connaught field seem to be intermediate between both. 
The extent of the coal-field is unknown; for although the coal 
at the margins of the exposed field must extend under the adjoin- 
ing younger rocks, this extension has never been proved by either 
borings or sinkings. 

The coals at Drumglass, near Dungannon, in the Middle 
Measures, have had their exact height above the Limestone proved 
by a series of bore-holes; but their extent is unknown, as it is 
still an open question whether they extend under the whole or 
only a part of the field. 


Krnanan—On Trish Metal Mining. 299° 


The coals of the Upper Measures in Annagher, Coalisland, and 
Annaghone have respectively individual characteristics. It has. 
been supposed that those of the Annagher series are above the 
Coalisland series, but there are no positive proofs that this is the 
case, while the facts appear to be against such a supposition. 
The Baltiboy coal of the Coalisland series is said to be the 
sixth or lowest coal of the Annagher series. This, according to: 
the published section, is, at the most, only 192 feet above the 
Derry or highest workable coal in the Coalisland series; while in 
the intervening measures there are four thin coals, ranging from 
nine inches to two feet in thickness; but in the bore-hole put 
down by Griffith for a depth of 270 feet below the sixth eoal 
at Annagher no coal was found. It is possible that these four 
minor coals might have died out, and be unrepresented in the 
measures under Annagher; but it is scarcely possible that 
the Derry Ooal, from three to five feet thick, should be totally 
absent. In the Annaghone Colliery, the Main Coal is said to be 
“undoubtedly” the Annagher Nine-foot Coal, which would necessi- 
tate a down throw to the eastward of over 2000 feet. It seems to 
me therefore more likely that the different series of coals in the 
several portions of the Upper Measures, are in more or less de- 
tached basins, in each of which the strata were accumulated under 
different conditions, similarly as in Kilkenny and Tipperary. 

We, however, do know, that in the Annagher series there are 
four coals, over 2°5 feet thick, more or less capable of being pro- 
fitably worked ; while in the Coalisland series there are three coals, 
over three feet high. The Annaghone colliery had a coal nine 
feet thick, and above it another that varies from 1° to 3 feet. 
There are no apparent reasons why these Annaghone coals may 
not extend northward and north-eastward under the Trias, even 
into the Co. Londonderry. 

From the very imperfect data at present procurable there is no. 
possibility of making any sort of an approximate estimate of the 
quantity of unwrought profitable coal in this portion of Ulster ; 
but it appears safe to suggest that there is probably much more 
unwrought coal here, than elsewhere in Ireland. 

The coals are bituminous, and when burnt have a white ash ; 
near the surface they are brittle, but improve in depth. They 
were not wrought, at least extensively, until the present century, 


300 Scientific Proceedings, Royal Dublin Society. 


‘when they were systematically looked for by Griffith and the 
Hibernian Mining Company. 

In places in the Coal Measures good clay-iron-stone is found ; 
‘but I cannot find any records of its having been raised or smelted 
in old or modern times. Elsewhere, however, in the Carboniferous 
Limestone and the Ordovicians, hematite and limonite were 
raised for smelting in the seventeenth and eighteenth centuries, 
and more recently for exportation (see Londonderry, page 288), the 
localities being given in the List, Part I. 

Antimony has been found in the Munterlong Mountains, and 
lead in Crockanboy and Trebane West, all near Gortin ; but none 
of the minerals appear to have been worked. In the Silurians at 
Crannogue, near Pomeroy, a little copper was raised ; while else- 
where in these rocks, both in this county and also in Fermanagh, 
there are traces and indications of this mineral, which would 
suggest that, if properly searched for, a paying lode might be 
found. 


WATERFORD. 


In the west of the county of Waterford is the eastern termina- 
tion of the rocks of the Cork types, they gradually, eastward and 
northward, changing into the ordinary Central Ireland types. 

To the eastward, coming in from the Co. Wexford, are Ordo- 
vicians, with their associated, more or less interbedded, igneous 
rocks; and over these, to the northward, are Lower Carboniferous 
Sandstones, Shales, and Limestones. But to the westward, in the 
Commeragh Mountains, on these Ordovicians are, more or less, con- 
glomeritic and argillaceous rocks; and these possibly are the 
representatives of the littoral accumulation of the Cork Devonian 
-or even Silurian ; this, however, has still tobe proved. To theS.H., 
at. the Bonmahon mines are a few patches of similar conglomerates, 
which for the reason stated hereafter (Wexford, p. 302) are supposed 
to be Silurians. Devonian (or Silurian) seem also to occur further 
south, in the long hill, or “drum,” between the two Decies. 


1 Clay-iron-stone is recorded by Boate as having being worked in the Calp (?) shales, 
in ‘‘ Nether Tyrone, by the side of the rivulet Lishan.’? ‘‘ Nether Tyrone’’ is the 
present Co. Londonderry. 


Kinanan—On Irish Metal Mining. dor 


On the Devonians(?), lying in nearly east and west troughs, 
are Lower Carboniferous Sandstone, Shales, and Limestones. 

In the Devonian rocks of the Coshs and the Decies baronies, 
that is, south of the valley from Lismore to Dungarvan; iron 
ore was extensively raised for smelting in the seventeenth and 
eighteenth centuries; Lord Cork having large works at Salters- 
bridge, while Sir Walter Raleigh’s principal mines were at Drom- 
slig; but the ores from Minehead and Ardmore were specially 
prized, as they could be converted into the finest steel. Here, as. 
elsewhere, the furnaces were probably in the vicinity of the mines. 
When Smith wrote in 1750, Lord Cork’s furnace only appears to. 
have been alight, and it was put out shortly afterwards. In 
Dromslig and the neighbouring townlands iron ore, for exportation, 
was raised between 1850 and 1860, and even a little later. 

Very valuable lodes, both of lead and copper, were formerly 
worked in different places in the Second, or Ballymoney Series of 
the Ordovicians. Lewis mentions a valuable silver-lead lode that. 
~ was worked at the Hill of Cruagh, parish of Riesk (Sheet 17); and 
another of lead in the River Mahon Valley, near Mountain Castle 

(Sheet 15) ; also silver-lead that was dug out of the sands of Kil- 
murrin beach. These three localities seem to have escaped 
Griffith’s notice, as they do not appear to be mentioned by him. 
Nothing is now known of the copper and silver-lead lodes worked 
near Ardmore ; but, from the specimens found in the waste heaps, 

they are supposed to have been rich. 

In this county the best known mines are the “ Bonmahon 
Coppers,” so called as the major portion of the ore was copper, 
although in the setts some valuable silver-lead veins were also: 
found and worked. At Knockmahon, mines were worked in the 
old days, as in the “Stage Lode” “Old Men’s workings,” with 
wooden and stone implements, were found. Subsequently, from 
Queen Elizabeth’s time, down to 1730, some of the lodes, at in- 
tervals, appear to have been worked, while at the latter date they 
_were in the hands of a Mr. Hume, who for some years worked the 
Stage Lode very successfully. Next we hear of Colonel Hall, and 

Mr. Galway, who spent a large sum unsuccessfully, and they, in 
1796, passed their interests to the Hibernia Mining Company. 
These also do not seem to have been successful, as they sold the 
property, in 1824, to the Mining Company of Ireland. The latter 


302 Scientific Proceedings, Roya Dublin Society. 


from that date, until about 1876, carried on the mining with vary- 
ing success; while about 1880 the works were totally dismantled. 
The last adventurers seem to have been more extensive in their 
operations than any of their predecessors, as they held five royalties 
—Tankardstown, Knockmahon, Kilduane, Ballinasisla, and Bon- 
mahon. ‘Their first mine was on the ‘“Trawna Stella” lode, in 
the west portion of Bonmahon ; hence the name by which all the 
mines were afterwards known. 

The future of these mines is very obscure, as from appearances 
there seems to be no hope for them; but it must be remembered 
that although adventurer after adventurer gave them up as value- 
less, yet the Mining Company found riches—the nett profits of 
the mines in 1862 alone exceeding £20,000. (See Du Noyer, Hx. 
Sheet 168, Geol. Map, p. 81). 


WESTMEATH. 


This area is occupied by Carboniferous Limestones, except a 
small exposure of Lower Carboniferous Sandstone near Moate, a 
second west of Kilbeggan, and a minute tract of Ordovicians, 
margined by Carboniferous Lower Sandstone, to the north of 
Killucan. 

This county is absent from Griffith’s lists, there being no recent 
mines in it. Small bits of lead and copper have been picked up in 
places; while coaly seams and clay-iron-stones have been found in 
the Calp shales. There is no prospect of profitable coal ever 
being found ; but copper and lead veins, especially the last, ought 
to exist, but are hard to discover on account of the envelope of 
drift and bog. 

In places there are the traces of old iron works, while it is 
possible that some of the Calp iron ores were utilized. 


WEXFORD. 


Two-thirds of this county are Ordovicians, in part metamor- 
phosed. These are fringed along their N.W. margin by Granyte, 
part of the great intrude of the Leinster range. S. EH. of the 
Ordovicians, and coming up from under them, are Cambrians. 


Kinanan—On Irish Metal Mining. 303 


The latter are also, in part, metamorphosed; those at Carnsore, 
to the south-east, being changed into Giranitic rocks. Patches of 
these rocks, for no apparent reason, except lithological characters , 
are said to be of ZLawrentian age. Crossing the Cambrian, and 
on the Ordovician, in Hook Promontory, are Carboniferous Lime- 
stones, Shales, and Sandstones. 

To the south-east, on the Cambrians, adjoining Ballygeary 
Bay, is a small outlying tract of Ordovicians. Formerly on the 
coast, to the S. E. of the new pier, the basal bed, a fine conglome- 
rate, identical in aspect with the silurian conglomerate at Bon- 
mahon, Co. Waterford (page 301), could be seen, but now it is 
covered up by a sand accumulation. 

The Ordovicians of S. E. Ireland are separated into three well- 
marked groups, which are traceable more or less distinctly in the 
rest of Ireland. These groups may be called, Lower—Black 
Shale Series; Middle—Volcanic, or Ballymoney Series ; Upper— 
Slate, or Slieve-Phelim Series. 

The known mineral veins are few, which may in part be due 
to the deep drift. A few veins of lead and copper, but not of 
much account, have been worked in the Ordovicians since the 
beginning of the century; while near Bannow Bay are attals, or 
old waste heaps, said to be the debris from mines worked by the 
Ostmen. 

In this neighbourhood, at the Castles of Clonmines, there is 
said to have been a mint in the time of Charles II., the coins 
having been made from silver procured in the vicinity. Some lead 
and barytes are found in the Carboniferous rocks, and in one place 
concretions of native sulphur. 

Prior to the stoppage of Chamney’s iron works at Shillelagh, Co. 
Wicklow (Wicklow, p. 246), these Iron Masters smelted iron largely 
in bloomeries in the north-west portion of the county, and probably 
also raised ore, as traces of what seem to have been old workings 
have been observed near Galbally and elsewhere. ‘There are also 
in different places, associated with the rocks of the Ballymoney 
Series, not only in this county, but also to the N.E., in the Co. 
Wicklow, and S. W. in the Co. Waterford ‘“ Black Heaps.” 
These are of greater or less size, and consist of roasted shingle and 
black stuff, with, in some of them, what seems to have been a 


hearth. Some of the smaller ones are said to have been the places 


304 Scientific Proceedings, Royal Dublin Society. 


where they “roasted the wild deer”’' in former times; but others 
evidently appear to have been bloomeries, or for some such meta- 
lurgical process. The roasted shingle is principally broken-up 
fragments of the Ferriferous Felstones. 

To the north of Gorey, at Ballynastraw, also elsewhere in the 
purple shales and slate of the lower portion of the Siate Series, 
are lentils, or irregularly-bedded masses of earthy limonite ; while 
in places along the Ballymoney cliffs are beds, of a low percentage, 
of calybite. There are no records of these ores having been 
worked. 

In the Ordovicians, anthracite, and in places plumbago, is 
recorded. At the north-east mearing of the county; in two places 
in the Ballymoney cliffs, where they have fire-clays and carbo- 
naceous shales associated; at Greenfield, near Enniscorthy ; near 
Wilton; in Doonoony; and near Castle Talbot; while it is re- 
ported to have been found in two places in the barony of Forth. 
From trials made the veins seem to be only from one to four 
inches wide, and of no value. Some of the best of the carbo- 
naceous shales, if there were mines in the neighbourhood, might 
possibly be worked advantageously as a bye-product. 

Some good specimens of asbestos are said to have been found 
at Bloomfield, near Enniscorthy. 


WIcKLow. 


To the north-east, adjoining the sea, are Cambrians ; the rest 
of the county rocks are Ordovicians, associated with a wide intrude 
of Granyte, part of the Leinster Granyte range. There are also 
small detached outbursts of Granyte, while the Cambrians and 
Ordovicians are in part metamorphosed. 

The Granytes belong to different Geological Periods. The 
main mass is Post-Ordovician, but with it, to the southward, in 
the parish of Shillelagh, and extending into Kildare and Carlow, 
is a considerable tract of a very coarsely crystalline rock, which 
might be called Pegmatyte (locally called Bastard Granyte). This 
evidently is newer than the normal “Leinster Granyte” of 
Haughton. In the older Granytes, also in detached intrudes, are 


1 Called Fellaght feca in the Co. Waterford. 


Kinanan—On Trish Metal Mining. 305 


the newer Granytes, which are possibly of Silurian or Devonian age. 
These younger Granytes, for reasons hereafter given, may possibly 
have some sort of connexion with the great Mineral Channel of 
the Co. Wicklow. 

Wicklow is the premier county in Ireland for mines, not on 
account of the ores being very rich, but in consequence of the 
great extent of the mineral ground, and that the mining operations 
have been in varying activity at intervals from time immemorial. 

The great Mineral Channel extends from near the sea, south- 
ward of Wicklow, nearly continuously, in a south-west direction, 
to Ovoca, and from that to the flanks of Croghan-Kinshella, a dis- 
tance of about fifteen miles. In the Channel, and adjoining it, 
the rocks are “iron masked,” similar to the rocks adjoining the 
intrude of the younger Granyte; this has led me to suggest that 
this Channel has a possible connexion with the vulcanicity to which 
the younger Granytes are an adjunct. In places along the Channel 
there were very ancient mining operations. 

At Connary and Cronebane, in the Hasr Ovoca Minzs, there 
was ancient mining for lead and silver, as has been proved in 
recent years by the finding of “Old Mens’ workings,” stones— 
hammers, and other primitive implements. Further south-west, 
at; Moneyteigue, there were other early workings, apparently 
for iron. Tradition has it, that iron was raised here by the early 
Trish, and that after the O’Helys were driven out of the country, 
the Norman knights, Raymond and Sillery, built castles in the ~ 
vicinity, and worked an iron trade. Towards the end of Eliza- 
beth’s reign, the Karl of Stafford (Black Tom), took possession 
of the county. He, and afterwards his successor, mined and 
worked iron, through their tenants, or Iron-Masters, the Paynes, 
the Bacons, and the Chamneys. 

The works belonging to the earlier protegés of this dynasty 
cannot be specially mentioned; but between Aughrim and Bally- 
naclash there are the ruins of very ancient iron works and mines, 
that are supposed to have belonged to them; as are also others on 
borders of this county and Kildare. 

Bacon, an Englishman, came over and built works at Shille- 
lagh. Before his time most of the charcoal was sent to Wales to 
be there used in the final working of the iron. He, however, con- 


sidered it would be more economical to import the pig-iron than 
SCIEN. PROC., R.D.S.—VOL. V. PT. IV. 


306 Scientific Proceedings, Royal Dublin Society. 


export the charcoal. This adventure was most successful, and 
at the time of the Commission for examining into the state of 
the Timber in Ireland, he had amassed a sum of over one million 
pounds. Having only one child, a daughter, the bait was too seduc- 
tive to one of the Commissioners, a scion of the twice noble house 
of Cholmondelay, who became Bacon’s son-in-law and successor ; 
relinquishing his heritage, and changing his name to Chamney.* 

The Chamneys greatly increased the trade; having works not 
only at Shillelagh, where Bacon established the industry, but also 
in the Vale of Clara; at Bally na clash, or “ Clash,’ in Glanma- 
lure; at Garrynagowlaun (Woodenbridge) and Aughrim, in the 
Vale of the Darragh Water; and elsewhere; besides innumerable 
bloomeries; his works, popularly, being said to have “filled the 
country.”” In an old document there are records of some fifty- 
two or more distinct works in Wicklow, Wexford, and Carlow. 
The “Clash” and Shillelagh iron was of a very superior quality, 
and at the present day any old chains or other articles made of it 
are highly prized by the smith.’ 

Bacon may have only manufactured imported pig-iron; but 
the Chamneys also smelted the native ores of Ballycapple, north-east 
of Redcross; and Knock na mohill mines, westward of Ovoca. 
Elsewhere in Ireland the Iron trade gradually ceased, as the 
woods were exhausted; but here it seems to have come to a 
sudden and untimely end prior to 1761, on account of a fracas 
between Chamney and the English agent of the lord of the soil.’ 


1 Although he changed his name during his life, and his descendants adopted the 
change, yet on his tomb in Carnew Churchyard, his real name and lineage are given. 

2 A smith who had a forge near Castle McAdam, is popularly reported to have gone 
night after night to abstract the ‘‘Clash iron”? staples and bolts out of the granyte 
gate posts, so common in the county. Whether he did it or not, the staples now, asa 

‘general rule, have all disappeared. I have known a pound of ‘‘Clash iron’”’ being 
exchanged for three pounds of the ordinary iron at present in use. 

3 Written information about the old iron works is very hard to procure, as nearly 
all the Chamney Papers appeared to have been destroyed when the family were dis- 
persed. Old people will tell you that ‘‘the noise of the Chamney hammer” was a 
weather guide, and show you bits of the Clash or Shillalagh iron ore pots; but no one 
seems capable of giving special information in respect to any of the old works; all say, 
<¢T supposed they belonged to Chamney, as they say he had works everywhere.” Also 
they know that the ore and his iron were carried in baskets on horseback from Wicklow 
port and from the different mines; and the old horse tracks from the mines and 
Wicklow to the furnace can stillbe shown. That the trail from Wicklow to Shillelagh 
must have been a very ancient one, is suggested by its passing the sites of Sillerey’s 
and Raymond’s Castles. 


Kananan—On Irish Metal Mining. 307 


The principal ore in the veins of the Mineral Channel is sul- 
phur-ore (Pyrites). This in general has a “back,” or “ gossan,”’ 
of iron ore, or ochre; while in places between the gossan and the 
real lode there is a “ gossan lode”’ principally of lead. There are, 
however, local peculiarities hereafter to be mentioned. Some of 
the sulphur-ore is coppery, having from two to four units of cop- 
per, while in newer lodes there was a mixed ore, in part pyrite, 
and in part chalcopyrite, that gave from six to ten units of copper. 
As these mines, at the beginning of the century, were worked 
solely for the copper in the ores they are generally known as 
“copper mines,” a title to which they are not entitled. 

The earliest workings of which we can detect traces were for 
lead, in Kast Cronebane, and for iron in Moneyteigue, after which 
history is more or less a blank till we come to near the end of the last 
eentury ; for although we know iron was extensively raised, prob- 
ably in the seventeenth and eighteenth centuries, at Knoch na 
mohill, Ballycapple, and other ores elsewhere; yet we cannot tell 
exactly at what time or by whom the mines were worked. 

At the end of the last century the Ovoca mines were in the 
hands of an English syndicate, who worked them for lead and 
copper. But early in the present century, the Channel immediately 
east and west of the Ovoca river seems to have been broken up 
into five mining setts: —Ballymurtagh, Ballygahan, Tigroney, Crone- 
bane, and Connary, which were let as ‘‘ Copper Mines,” and when first 
worked any poor pyrites raised was run into spoil. But about the 
year 1840, on account of the high price of sulphur, the character 
of the mines quite changed, as instead of being working for copper 
they became “Sulphur Mines.” While the great demand for sul- 
phur lasted, vast sums were made by the different adventurers ; 
and, as in late years, there was a demand for iron ore, it also was 
a considerable source of profit. The great demand ceased about 
the year 1865, and afterwards the mines rapidly declined, and 
now little or nothing is being done.’ 


1 From Boate’s history and Petty’s maps it would appear as if Wicklow wasa terra 
imeognita ; the first authority does not mention anything in it (the Co. Wicklow), while 
the second leaves the track a blank in his maps. 

* The decline was gradual; the Spanish ore—with its 48 units of sulphur, 3 of cop- 
per, and 25 dwt. of silver, also an unlimited supply—gradually drove the Irish ore out 
of the English market; although for a long time the Irish ‘‘ Coppery Pyrites’’—40 

RNG 


308 Scientific Proceedings, Royal Dublin Society. 


The future prospects of these mines is an important considera- 
tion, and the present state of the different setts is therefore of 
interest. This will be briefly given from the N. E. to the 8. W.. 
of the channel. 

Southward of Wicklow town, at the north-east end of “The 
Channel,” is the Ballycapple Sett, in the townlands of Ballycapple 
and Ballard. The iron bark of this lode, which seems to have 
been very rich, was worked in the time of the Chamneys, the ore 
being carried on horseback to the works at Ballynaclash in Glen- 
malure. Some of it also seems to have been smelted in bloomeries. 
in the vicinity of the mines, as their sites are‘ still to be seen 
From the fragments in the attals, the “true lode” seems to be 
a coppery pyrite, but it was never worked. Just before the work- 
ing ceased the miners were driving up from the south an adit to 
drain the mine. This was recently opened, and was found to end 
some ten or fifteen fathoms short of the lode. In 1852 trials were 
made in search of “copper ore,” but with what results are not 
recorded. In 1875 a few tons of iron ore were raised, also 
brownish ochre, from the back of the lode in Ballycapple Hill. 
The latter, and the “black stuff’? from some of the ancient 
bloomeries were exported to be used in the purification of gas. 
Up to the present time only the iron back and ochre have in part 
been removed, some stones giving high analysis; they, however, 
do not represent the average iron ore. ‘The true lode itself, does. 
not appear to have been broken, and its nature, value, and extent 
have still to be proved. 

Between Ballycapple and Kilmacoo, a distance, in a S. W. 
line, of about three miles, the country is very little known. In it 
the regular Channel has not been found; but in places there are 
small veins of copper, sulphur-ore, lead, and zinc. It is possible 
that the trials made have been too much southward ; because in 
the townland of Rockfield, about a mile N. N. KE. of Kilmacog, is 
an assembly of “shode stones,” very similar to those that elsewhere 
occur in connexion with the Channel; the Channel may be there- 
fore heaved northward. 


units sulphur and 2.50 copper—held its own. As a general rule, the Irish pyrites is 
much more free from arsenic than the Spanish ore, and therefore more suitable for the 
manufacture of the pure sulphuric acid. 


Kinanan—On Irish Metal Mining. 309 


S. E. of Kalmacrea Pass, in the north part of Coolanearl, is an 
old shaft; but there is no information in connexion with it. 

The break a little east of Kilmacoo, or Connary cross-roads, 
cuts off the Mineral Channel, and heaves it, apparently northward 
as just suggested. On the Channel between it and the Ovoca 
river lie the Hast Ovoca Mines. Of these mines an exhaustive 
description was published, in 1879, by P. H. Argall, formerly 
agent of the Magpie.’ They are in two groups—to the north- 
eastward, [i/macoo, Connary, and the Magpie, or East Cronebane ; 
and to the south-westward, West Cronebane and Tigroney. 

In the north-east division there are two main lodes, ir- 
regularly wedge-shaped, the walls closing in depth on account 
of the hanging or south wall, standing more perpendicularly than 
the foot or north wall. The Mineral Channel and the lodes were 
formerly supposed to have been deposited contemporaneously with 
the associated rocks, but recent research has shown, that although 
the general direction of the lodes may be more or less with the 
strike of the “‘ country rocks,” yet the Channel and lodes always 
eross the latter, though sometimes at a very small angle, while 
in depth both dip at a greater angle than the “country 
rocks.”’ 

The north lode is principally sulphur-ore, often coppery; it is 
more or less friable, and accompanied with soft ground. In 
Oonnary, south of the lode, there is a massive rib of quartzose rock, 
with native copper disseminated through it, which is not found in 
the Magpie. Between the lode and its “ gossan” (iron and 
ochre) there was an auriferous argentiferous lead ‘ Gossan lode,’’ 
remarkable as in it there were minerals not found in the underly- 
ing lode. In Kilmacoo, in old times, there appears to have been 
an adit that was driven in from the north slope; this, however, has 
been closed up for years. Between Connary and the Magpie there 
is a N. and 8. left-hand heave, along which there was a lead lode. 
‘The lead in the Gossan and Cross lodes was worked in very old 
times, while the rest of it was abstracted during the present 
‘century. Some of the sulphur ore still remains, but not much, as 
the “Wedge” has been bottomed in different places; it is, how- 


1 On the Ancient and Recent Mining Operations in the East Ovoca Distriet.—Scien- 
tific Proceedings, Royal Dublin Society, 1879. 


310 Scientific Proceedings, Royal Dublin Society. 


ever, possible that, if sunk on still further in depth, the walls 
might again separate.’ 

The south lode occurs in Kilmacoo and the Magpie, it being 
principally “ blue ground,” in which are the veins and pockets of 
Kilmacooite or bluestone. This peculiar mineral appears to be an 
admixture of the sulphides of zine, lead, iron, copper, antimony, 
arsenic, and silver, with a trace of gold; but it varies greatly 
and rapidly. It was known in Weaver's time; as the Coppery 
ore in Madame Stephens’ lode is mixed with it; while a vein 
was cut in the “Lodge level.”” Weaver seems not to have 
been able to utilize it, while at the present day it cannot be 
economically reduced. At the present time the typical ore has 
only been proved in the places above named ; but a variety was 
found in West Cronebane by Argall, and Haughton mentions a 
variety that occurred in Ballymurtagh, the latter in places being 
very auriferous (page 206). If, however, the economical reduction 
of this ore is hereafter understood, it is probably that elsewhere 
in the courses of “ blue ground” it may be found. 

A careful analysis of this ore is most important, as, on account 
of the various constituents and their peculiar relations to one: 
another, hand specimens are very different, some being very rich, 
others very pvor; and unless the greatest care is taken in selecting 
specimens for analysis, the results may afterwards be most disastrous 
to the well-being of a mine. This caution is necessary, as the 
analyses published show that in most cases the ores examined were 
picked rich specimens, which although of interest to the mineralogist, 
are pernicious to the mine, as they lead to false hopes, which can 
never be realized. The Magpie has been so-called from the black 
and bluish-white ground found in the lode associated with the 
ores. 

To the westward of the Magpie, between it and West Crone- 


1 In the deepest working (Williams’ shaft, Tigroney) the walls appeared to be again 
separating. In some of the Cornish mines when the Copper lode had died out, on 
sinking deeper, tin ore was found. This appears to be a consideration in connexion 
with the future of these mines, more especially as tin must exist somewhere in the- 
county, having been found in the ‘‘streamings’’ for Gold. Furthermore, in the Magpie 
shaft the lode in depth was cut out by a Granyte protrusion ; and, if the lode continues 
in depth, the mineral contents might possibly change. If these mines hereafter gave 
new riches in depth, they might be economically worked, by driving up Weaver's. 
deep or ‘‘ Boat level.”’ 


KrnaHan—On Trish Metal Mining. oli 


bane, is the tract called the Yellow Bottoms, or Dead Ground. The 
latter name was probably given to it in Weaver’s time, because 
the ‘‘standing copper lodes” of West Cronebane do not extend 
intoit. In connexion with it are Madame Bulev’s, and some other 
mineral lodes; while from explorations made in 1879 and 1880, it 
would appear that there is also a large sulphur-ore lode, the back 
of which forms the ochre beds that were worked in 1882, and sub- 
sequent years, for the manufacture of paints. 

The south-eastern division (West Cronebane and Tigroney) is 
cut off by a fault from the Yellow Bottoms, the nature of which 
has not yet been explained. In connexion with this fault all that 
can be positively stated is, that the Mineral Channel to the east- 
ward and westward have characters markedly distinct, the lodes 
having different characters, while some of the minerals found in the 
first are absent from the second. 

The main lode in West Cronebane and Tigroney is wedge- 
shaped ; hard sulphur-ore and some coppery-ore occurring in lamina 
parallel to the foot wall; while south of it there were “standing 
lodes””—thin long cake-like masses of coppery-ore. The standing 
lodes are all worked out ; principally in the early part of the present 
century. The main sulphur lode has been extensively worked of 
late years, and very little ore now remains; unless it is possible 
that in depth the wall again separated (see note, last page). About 
1880 the irony back of a lode was proved in the wood south of 
Castle Howard ; it appearing in the position where the North lode 
of Ballymurtagh ought to be found. 

In the county, north of Cronebane and Connary, are minor 
veins: one, Lion’s Arch lode, north of Castle Howard, having been 
worked profitably between 1870 and 1880 for iron and sulphur- 
ore. Some of the other lodes might be remunerative if worked in 
connexion with one of the larger lodes. 

A deep level was commenced near the old Glebe in Shrough- 
more, which was to have been carried south-east till it cut the 
Connary lode: unfortunately this was not continued, as there are 
reasons for supposing that it might have cut more than one lode 
in its course. 

Copies of the plans, and sections of the majority of the old and 
new workings in the East Ovoca Minzs are lodged in the Mining 
Record Office, London. 


312 Scientific Proceedings, Royal Dublin Society. 


To the west of the Ovoca River are the West Ovoca Minzs, 
including the two Ballygahans and Ballymurtagh. 

Ballymurtagh and Lower Ballygahan are divided from the 
East Mines by a channel of dead ground in the Ovoca River 
Valley, which heaves (left hand) the latter northward. In these are 
the North and South‘sulphur lodes ; while south of the latter are the 
Standing coppery lodes, all the lodes being in character respectively 
similar to those in the Tigroney and West Cronebane setts. There 
is a slight left-hand heave near the boundary of Ballymurtagh 
and Ballygahan. Last of this, in the latter, the north lode 
carried coppery ore only ; while in the Ballymurtagh North lode 
there is a gossan of iron, or ochre, on a rich sulphur lode. Here 
there was no gossan lode; but in places between the gossan and 
the lode was a large ‘“(vug” full of water. Much of the ore in 
these lodes is still unbroken. 

In Ballymurtagh, between the North and South lodes, there 
was a shoot of ore, ‘‘ Pond lode:” this is worked out. In the 
South lode, Ballymurtagh, the ore has been broken more or less 
to 110 fathoms below the Margaret level, and in Ballygahan to 70 
fathoms below the adit, the deepest working in the first being 
24 fathoms below the deepest in the last. At the breast of the 
workings in Ballygahan, at 60 fathoms, the ore gave 37 units of 
sulphur, and 4:4 units of copper, the course being over 11 fathoms 
wide, the south hanging wall not having being reached. Bally- 
murtagh and Ballygahan would be more profitably worked as one 
mine; because at any time, on account of the underlie of the 
South lode, the portion in Ballymurtagh could be undercut by 
a level in Ballygahan. 

In Ballymurtagh South lode there was a lenticular mass of an 
ore allied to Kilmacooite, it in places being very auriferous.' 

- In no place in either Ballygahan or Ballymurtagh has the 
bottom of the lode being reached; while in both there are good 
breasts of unbroken ore. Copies of all the plans and sections of 
these mines are lodged in the Mining Record Office, London. 


1 In Culvert’s analysis, in five out of six, there is a return of gold, while in the 
analysis by Apjohn and others no gold was found. This is another example of the 
care with which specimens should be selected. Culvert’s specimens were from this 
peculiar ore, which did not represent the true lode, and therefore raised a false hope. 


Kinanan—On Irish Metal Mining. 313 


In the Mineral Channel south of the Ballygahan portion of the 
lode there were Standing veins of coppery ore; but as these were 
followed westward they joined into the South lode of Ballymur- 
tagh. ‘These coppery lodes for the most part are worked out. 

In the county immediately north of Ballymurtagh and Bally- 
gahan there are a great many small veins of sulphur-ore, with a 
few of lead. Various trials have been made on the sulphur-ore 
lodes, none of which are of good promise; but some of the lead 
lodes seem to have been worked by the “‘ Old Men.” 

Westward of Ballymurtagh, in Upper Ballygahan, Killeagh, 
and Ballymoneen there are various traces and small veins, on 
which numerous trials have been made without success, looking 
for the continuation of the mineral channel in the strikes of the 
Ballymurtagh lodes, as the Ballymurtagh lodes, seem to become 
poor, as if they approach a left-hand heave; the trials seemingly 
ought to have been made more to the south, in the townland of 
Ballinapark. 

Farther south-west are the Sourm Wesr Ovoca, or Kwock- 
NAMOHILL Minzs, including the portions of the Channel in Bally- 
moneen, Ballinapark, and Knocknamohill. Here there also seems 
to be both North and South lodes. The gossan, or iron back of 
the first was extensively worked in the Chamney times; and in 
late years a large “parcel,” of ore, was raised to the east, in 
Ballymoneen (“ Hodgeson’s shaft”). The ore was rich, giving 
75 units of iron; but when worked the iron was “ old short.” 
Mr. W. E. Adeney, Analytical Chemist, Royal College of Science, 
who has lately analysed the ore, states:—“ The fact of its going 
cold short was due to the phosphoric acid; but by the method of 
Gilchrist now employed, phosphoric acid is no detriment; on the 
contrary, in ores that contain little silica, as this one does, phos- 
phorie acid is an advantage, and, I think, this ore might be tried 
by Gilchrist’s method with great success.” 

In these townlands the lode under its iron back (gossan) does 
not appear to have been broken, and the nature of the minerals is 
unknown. A shallow level, apparently to drain the Iron Mining, 
was driven up northward from the mearing of Ballinapark. The 
Channel and lode to the westward is cut off in Knocknamohill by 
a fault. 

The south lode appears to have been unknown to the “Old 


ol4 Scientific Proceedings, Royal Dublin Society. 


Men.” About the year 1840 it was sunk on by Crockford, and 
some 400 tons of coppery-ore raised ; but the adventurer getting 
into difficulties, the mine was abandoned, and no further work was. 
done. 

South-west of Knocknamohill, in the Valley of the Darragh 
Water, or Aughrim River, there are unknown complications; the 
Mineral Channel not having been found from where it is cut off 
by the Knocknamohill N. & 8. fault till it is met with again 
south of the valley, in Ballycoog. 

To the south of the Darragh Water are the Carysrorr Mrnzs. 
From Ballycoog to Moneyteigue, north of Croaghan-Kinshella 
the Mineral Channel can again be traced, having in it two or three 
lodes of sulphur or coppery-ore. ‘They, however, are not conti-: 
nuous, being shifted three or four times, by left-hand heaves. 

There were old workings at Ballycoog and Moneyteigue, espe-. 
cially the latter, for iron ore; while in late years various trials 
were made by the Carysfort and other Companies, some iron and 
good coppery-ore (8 to 12 units of copper) having been raised at 
Moneyteigue. In the other places the works were far from satis- 
factory, as they evidently were entrusted to incompetent hands ; 
and after vast outlay during a number of years, none of the lodes 
lave been proved, except at the surface ; consequently their nature- 
in depth is quite unknown. 

To the north-west of Croaghan-Kinshella there are mineral 
indications, but no trials appear to have been made. 

To the south of this portion of the Mineral Channel, in the tract 
south of the Darragh Water, and west of the Ovoca River, various. 
small veins of lead, sulphur, and coppery-ore have been found ; but 
none seem to be of much promise. Some lead ore was raised at 
Ballintemple, westward of Woodenbridge, but the vein was 
small. 

Although the Mineral Interests in the county, as is so general 
elsewhere, is now at a low ebb, they must at some time mend. It 
is, therefore, expedient to give a brief forecast of what may be the. 
prospects along the line of the Mineral Channel. 

Ballycupple and Ballard.—The lode under the iron and ochre 
back unbroken. 

Rockfield.—The origin of the ‘“‘ shode stones ” still to be traced. 
out. : 


Kinanan—On Irish Metal Mining. 315» 


Kilmacoo and Connary.—The Kilmacooite may become a pro- 
fitable ore. In depth the walls of the main lode may separate.. 
‘There is also the chance of a lode being found to the northward 
between Connary and Shroughmore. 

Magpie-—The Kilmacooite may become valuable, and in depth: 
the walls of the main lode may separate. 

Yellow Bottoms.—A sulphur-ore lode probably exists under the 
ochre bed. 

West Cronebane and Tigroney.—The walls in depth may sepa- 
rate. The North lode in Castle Howard Wood is totally un-- 
broken. 

Ballygahan Lower and Ballymurtagh.—The deep ore in the 
South lode unbroken. In the North lode only a small portion of 
the ore abstracted. 

Ballinapark, Ballymoneen, and Knocknamohill.—The iron back 
of the North lode is more or less removed, but the lode appears to 
be unbroken. The South lode only broken in one place. 

Ballycoog, Ballinasilloge, and Moneyteigue-—Vhe lode proved 
in Moneyteigue, where iron and coppery-ore has been raised ;. 
but elsewhere the nature of the lodes have not been satisfactorily 
proved. 

From the foregoing notes it will be seen that there are other 
places in which prospects are not discouraging. It cannot, how- 
ever, be said, without further trials, that there is a prospect of these 
making future mines. 

The other mines, also well known, are those on the lead lodes 
in connexion with the great Granyte intrude in the northern 
portion of the county, they being principally situated in the 
tributary glens to that of Glendalough and in Glenmalure.. 
Luganure, or the upper portion of Glendasane, one of the 
branches from the first, being the principal centre of industry. 

In the beginning of the century the mines in these and a 
few of the neighbouring glens were opened up by Weaver, who: 
described the lodes in his Paper read before the Geological Society 
of London, May, 1818. In 1853 they are further described 
by W. W. Smyth, vol. i., part ii., Records of the School of Mines ; 
but subsequent to the latter there were valuable reports on in- 
dividual mines by others, especially those by Griffith. Since 
Smyth wrote, no new lodes seem to have been found, the works. 


“316 Scientific Proceedings, Royal Dublin Society. 


up to late years being on those then known, or on branches from 
them. 

These lodes seem all to have been in the region of the junction 
between the Granyte and Schist, in the first being more or less rich, 
in the latter in general poor or nearly valueless; while in a few 
places at the contact there were good bunches of ore. In Glendas- 
‘san, associated with the galenite, were cerusite, sphalerite, and pyro- 
morphite, the lead ores (galenite and cerusite) giving eight to ten 
ounces of silver to the ton. Of the numerous veins the largest 
was that called the Camaderry lode. In late years, on account of 
‘the low price of lead, the works gradually slackened off till 1880, 
when they came to a stand still. 

The lead veins in Glendalough were remarkable, being asso- 
-ciated with chalybite (carbonate of iron), the latter in one place 
being eight feet wide. The workings on these lodes have been 
-discontinued for years, the lead veins being too small to pay at the 
low prices for lead. 

In Glenmalure there are numerous small lodes, or strings of 
lead, all of which have been more or less explored. The only 
mine that gave returns was that at Ballinafunshogue, to the east 
of the River Avonbeg. This, when in full work, was stopped, the 
lease having expired, and excessive terms, it is said, being asked 
for a renewal. ‘The ores in the lode were galenite, barytes, 
sphalerite, and specks of chalcopyrite. 

To the west of the Avonbeg, at Baravore, there are appear- 
-ances of a good lode; but only partially explored. Here barytes 
was in quantity, and of very good quality. In Clonkeen with 
the lead there was chalybite. 

Westward of Glenmalure, at the North Prison, Lugnaquilla, 
as a lode of lead, very favourably reported on by the late Henry 
Robinson ; but it is very difficult of access. Lead also occurs 
to the southward of Lugnaquilla, at the waterfall, northward of 
the Aghavannagh Barracks. 

Eastward of Glenmalure lead is recorded, at Cullintra Park 
and.at Loughs Dan and Tay, &c. Lewis states the lode at Lough 
Dan is worked out. 

The localities for the gold and tin found in this county are 
given in the Lists, Part I. In connexion with a “ gold digging ” 
there are the quartz reefs, the shallow placers, the deep placers, dry 


KinaHan—On Irish Metal Mining. 317 


guich placers, and shelf or bar placers. | Possibility of gold being 
found in the Co. Wicklow. —Proc., R.D.8., February 19th, 1883. ] 
In the Wicklow diggings the reefs have been unsuccessfully 
looked for; while the gold was principally worked in the “ shallow 
placers,” and in a few cases in the “dry gulch placers;” but 
neither the “deep” or “bar placers” have been explored, at 
least in modern times. Tin was found in some of the “ shallow 
placers.” 

Fluorspar is recorded as occurring both crystalline and massive 
in the Glendalough Mines; but the quantity is not stated. It is 
now valuable as a flux for iron. 


NOTES IN PRESS. 


Donegal, Ordnance sheet 58.—South side of Glenaboghill Lake, one- 
mile N.N.K. of Fintown; a N.E. and 
S.W. lode of Silverlead. 


50.—At the head of the Owenbeg, Glen- 
dowan, a thin lode of lead. 


99 99 


Boag-tron-orE.—Mr. W. E. Adeny states: ‘‘ After it has been used 
for the purification of the gas, the ammonium salts are first extracted 
from the spent ore by means of water; the fine ferriferous powder 
deposited being very valuable in the manufacture of brown paint. The 
residue then dried and burnt for sulphuric acid manufacture. The 
cinder left after burning off the sulphur is often sent back to be re-- 
used for washing gas.” 


F318) 19 


XXVIL—THE “Cd@CAL PROCESSES” OF THE SHELLS 
OF BRACHIOPODS INTERPRETED AS SENSE- 
ORGANS. By PROFESSOR SOLLAS, LL.D., 
D.Sc., &e. 


[Read, November 18, 1885. ] 


In the course of investigating the Tetractinellida, brought 
home by H.M.S. Challenger, I had occasion to cut thin slices 
-of the decalsified valves of a specimen of Waldheimia cranium 
which had been overgrown by an incrusting sponge. On examin- 
ing these slices under the microscope with a view to determining 
the structure of the sponge, I was at once struck with the resem- 
blance of the processes filling the tubules in the shell of this 
Brachiopod to sensory aid organs; and as on referring to Van 
Bemmelen’s! account of the Brachiopod shell I found no mention 
_of this, I thought it might be worth while to draw up the follow- 
ing short account :— 


The tubular processes which vary greatly in length, and though 
occasionally simple, are usually branched, and sometimes repeat- 
edly so, are transparent and colourless for the greater part of their 
course, bearing small but evident nuclei in the walls indicating the 
epithelial cells of which they are constituted. In the centre they 
show traces of an axial fibre, visible both in transverse and longi- 
tudinal sections, and probably of nervous nature, as it can be 
traced into continuity with the nerve cells of the mantle. At the 
outer end of the tubule its appearance rapidly, almost abruptly, 
changes, presenting a single large finely-granular cell with a large 
oval nucleus and spherical nucleolus ; both cell and nucleolus stain 

deeply with hematoxylin. Closer investigation reveals the pre- 
sence of numerous additional nuclei, some of which appear to 
belong to the epithelium of the outer wall, which thus continues, 
if this be so, as an investment to the terminal cell. In other 


, ? Over den Bouw der Schelpen van Brachiopoden en Chitmen, Docter-Dissertation, 
1982, Van Bemmelen. 


Sottas—On “ Cacal Processes”’ of Shells of Brachiopods. 319 


eases there appears to be more than one terminal cell. The inner 
end of the terminal cell appears to be prolonged into a fibril, 
which can sometimes be traced into continuity with the nucleus 
on the oné hand, and with the axial fibre on the other. The 
outer end of the cell abuts against the lower face of the perios- 
tracum, and thus ends smoothly and abruptly, not giving off hairs 
or any other processes; the fine striation which occurs at the end 
of the cell, and which has been figured and described by Van 
Bemmelen, being of another nature. The periostracum imme- 


m = mantle. n = nerve cell. s = shell. é = end of cecal process. 


diately over the end of the tubule appears to easily separate from 
that surrounding it, since I find the end organs adherent by 
means of the {overlying periostracum to the base of the incrusting | 
sponge, while the rest of the periostracum has disappeared from 
around them, 7.e., been torn away in the process of cutting. 
Tracing the ccecal tube inwards, the axial fibre is continued 
into the nervous layer of the mantle, as already mentioned; the 


320 Scientific Proceedings, Royal Dublin Society. 


walls, on the other hand, continue into the pavement epithelium 
investing the exterior of the mantle, of which they are demon- 
strably nothing else than an extension. This is most plainly 
shown in very young processes to be met with near the point 
margin of the mantle, and which consist of but a few cells; the 
terminal cell being of a hemispherical form with the rounded 
surface outwards, and evidently nothing more than an enlarged 
epithelial cell. 

The ccecal tubes of Waldheimia cranium are, therefore, epider- 
mal outgrowths, with a large granular invaginated terminal cell, 
which at one end is continued into a nerve fibril, and at the other 
covered by a transparent chitinous layer, separating it from all 
external influences likely to serve as stimuli, except that of light. 
It would therefore appear that the transformation of this form of 
radiant energy into nervous disturbance is the function of the 
so-called coecal processes. Still further investigation is however 
necessary before this view can be fully adopted, especially as a 
serious objection to it exists in the absence of anything like 
pigment in the terminal cells. Better material than that at my 
disposal may, however, throw further light on this and on other 
points which in my sections remain obscure. 


AXVIT.—ZINC AND ZINC ORES, THEIR MODE OF OCCUR-— 
RENCE, METALLURGY, AND HISTORY, IN INDIA; 
WITH A GLOSSARY OF ORIENTAL AND OTHER 
TITLES USED FOR ZINC, ITS ORES, AND ALLOYS. | 
By V. BALL, M.A., F.R.8., Director of the Science 
and Art Museum, Dublin. 


[Read, December 15, 1886. ] 


Some years ago I presented to this Society several Papers on certain 
of the mineral productions of India, regarding which no general 
accounts founded on the geological examination of the country had 
up to that time appeared. Since then I have written a volume on 
the Lconomie Geoloyy of India, in which is incorporated all that 
could be ascertained regarding the useful minerals of the country 
up to date. In the preparation of that work, the more or less 
casual references to the occurrence of useful minerals which are 
to be found in the writings by travellers in India during the past 
2000 years were as far as possible explained and relegated to their 
proper places. Owing partly to the great extent of the literature 
which exists in the languages, both ancient and modern, of many 
different nations, and also owing to the fact that many of the 
works known to me were not accessible in Caleutta when I wrote 
the Economic Geology, it was unavoidable that the references to the 
original authorities were incomplete. I have, however, during the 
past five years devoted a large amount of time to reading up all 
that I could meet with bearing on the subject, and in that pursuit 
have acquired, or had opportunities of seeing, a number of rare old 
books on India which have proved a valuable mine in which the 
information is no doubt widely scattered, in so far as any one sub- 
ject is concerned, but in which much information regarding many 
different subjects is to be found—the result being that | have been 
enabled to collect a considerable store of facts, which I hope to 
publish from time to time in a series of Papers more or less similar 
to the present. 

The subject of this Paper is, as I think I’shall be able to demon- 


SCIEN. PROC., R.1).8.—VOL. Y. PT. Y. Z 


322 Scientific Proceedings, Royal Dublin Society. 


strate, one of particular interest, in consequence of the fact that zine, 
as an isolated metal, has only been known in Hurope in compara- 
tively recent times,’ though several of its combinations with other 
metals were made known to Western nations by the traders who 
brought them from the far Hast at very remote periods of the world’s 
history. 

In several parts of India traces of zinc ores have been met with 
(chiefly the sulphide or blende) in association with ores of copper and 
other metals; and to this circumstance may perhaps be attributed 
the fact that Abdul Fazl, the author of the Ain-i-Akbari, in an 
enumeration of metals which were obtained in the rivers of the 
Subah of Lahore, includes brass.” It is conceivable that this refers 
to a metal obtained in smelting an undesigned or natural combi- 
nation of ores, which was really brass instead of copper, and hence 
the ridicule with which the statement has been criticised is perhaps 
not exactly deserved. 

That brass was discovered first by such an accident appears to 
be generally admitted. Afterwards it was manufactured by the 
addition of natural calamine to molten copper, and even, when that 
was not obtainable, by the addition of artificial calamine scraped. 
from the chimneys of smelting furnaces.* Upon this subject, and 
its connexion with the alchemist’s search for gold, some information 
will be found in Beckmann’s History of Inventions.‘ 

Beckmann, who regrets the scantiness of the available informa- 
tion about India, says that the zine came from China, Bengal, 
Malacca, and the Malabar Coast, and adds that an Englishman 
went to India inthe 17th century to discover the process used there 
in the manufacture, and returned with an account that it was 
obtained by distillation per descensum. I have not yet been able 
to identify this Englishman. 

By a curious fatality, the principal zine mine in India, of which 
we have certain knowledge, was described by Col. Tod,* incidentally, 


1 The name is first mentioned by Paracelsus in 1616, though the metal appears to 
have been known to Albertus Magnus in the 13th century. 

2 Gladwin’s Ed., vol. ii. p. 109. 

3 Known to Albertus Magnus in the 13th century. 

4 See Bohn’s Ed., ii. p. 32. 

5 Rajasthan, vol. i. p. 504. 


Batu—On Zine and Zine Ores. 3233 


asa tin! mine, and this statement has led Lassen! and others to 
conclude that in early times tin was produced in the peninsula of 
India itself; but we are not at present justified in believing that 
there was at any time a largely-worked source of tin in that 
country, and we are therefore driven to the conclusion that all the 
tin exported from Indian ports was first brought to them from 
Tenasserim or the Malayan Peninsula and its islands. 

This mine is at Jawar or Zawar, in the Udepur State of Raj- 
pootana. Tod states that the annual revenue derived from it 
amounted to a sum exceeding £20,000 (222,000 rupees); so that 
the produce must have been considerable, and independently the 
extent of the excavations points to the same conclusion. 

The mine of Dureeba, or Daribo, which Tod also mentions as a 
tin mine, yielding a revenue of 80,000 rupees, was, it is believed, a 
copper mine. 

The ores at Jawar, so far as is known, consist of the carbonate 
or Smithsonite,? and argentiferous galena, but no traces of tin 
ore have been met with, nor is there any local tradition of tin ever 
having been produced there. The including rocks are believed to 
be quartzites of the Arvali group of the transition series. 

The following account is derived from a Paper published in the 
year 1850 by Captain Brooke, who acquired most of his informa- 
tion from one of the native miners, still living on the spot, who 
had worked in the mines before the famine of 1812-183, when they 
were closed. He described the ore as occurring in veins three or 
four inches thick, and sometimes in bunches, in quartz rock. The 
pure ore, being very friable, was pounded, freed from quartz, and 
placed in crucibles some eight or nine inches high and three 
inches in diameter, with necks six inches long and half an inch in 
diameter. Into these necks the metal sublimed on the applica- 
tion of heat in the following manner: the mouths being fastened 
up, the crucibles were inverted and placed on a charcoal furnace. 
It took three or four hours to complete the fusion of the ore. It is 


1 Lassen, Indisch Alt., vol. i. p. 232, was, however, aware that zinc occurred in © 
India, as he refers to Captain Brooke’s Paper, quoted below. 

2 Much confusion exists, owing to the application of the term calamine to both 
the hydro-silicate and the carbonate. See Dana’s Mineralogy on this subject of 
nomenclature. 


Z 2 


324 Scientific Proceedings, Royal Dublin Society. 


stated that the crucibles used to crack if any fragments of the 
matrix were inserted into them with the ore. 

An account of these mines was published in 1872,! which is: 
merely of value here as testifying to the great extent of the exca- 
vations, and to the former wealth and importance of the place, 
which is afforded by ruins of forts, temples, &c. As for the ores, the: 
information about them is not only scanty, but probably incorrect: 
it is that “veins of almost pure lead ramify through the primitive: 
rock, whilst beautifully-coloured ores of the mineral sparkle over- 
head. Silver is obtained in small quantities, whilst gold has been 
found, it is said, on several occasions.” It is possible that the so- 
called almost pure lead was argentiferous galena; but the gold is 
probably mythical. 

So far as I know, these mines have not yet been described by 
the Geological Survey of India; but a description by Mr. Hacket 
of the geology of the States of Rajpootana, which adjoin Udepur, 
and in which the Arvali rocks are strongly represented, was 
published some years ago.” 

There are reasons for supposing that some of the mines in 
southern India, especially those in the Karnul district at Gazal- 
pully, or Baswapur, may have produced zine,* and it is possible that 
metal from these local sources may have in early times supplied 
the workers at Beder with their material. Other reported occur- 
rences of zinc ores in India are, so far as is known, of triflmg 
importance. 

There can be no doubt that zine, as a constituent of various 
alloys, has been largely used in India since the earliest times re- 
corded by history; thus in the 6th century Sopater mentions brass as 
being obtainable at Calliana, a port in Bombay ; and as it is certain 
that a large amount of these alloys reached India by means of the 
trade with China, I shall presently refer to what is known of that 
part of the subject. 

In Materia Medica, too, especially im the treatment of cutaneous 
diseases, evidence is available of the employment of preparations of 
zine since very early times in India. 


1 Indian Antiquary, vol. i. p. 63. 

2 Vide Records of the Geological Survey of India, 1881, p. 279. 

3 See Mallet, Records, Geol. Surv. India, 1881, p. 808, and Leonomie Geology of 
India, pp. 284 and 312. 


Batt—On Zine and Zine Ores. 38290 


An analysis by the late Dr. Walter Flight! affords some inter- 
esting information of one manufacture in which zine is largely used. 
He says that the well-known “ Bidri” ware of Beder, in Hyderabad, 
consists of a metal into which plates of silver about the thickness 
of writing-paper are pressed into, the undercut grooves forming the 
pattern. The two metals adhere, and are then finely polished. 
The materials forming, I. a box, and II. a bottle, gave the follow- 
ing results :— 


I. Il. 
Zine, by difference, ; : 3 94°552 93°516 
Copper, ‘ ; : ; : 3°920 3°278 
Lead, . 2 F ; ; h 1:400 Daeg 
Golde: F : ; , : —— 0-690 
icomeeue } : ' ; 5 0:128 0°345 


These proportions seem to suggest a doubt as to the material 
being a specially prepared alloy. It might, perhaps, result from 
the reduction of an ore of zinc containing the other metals in 
combination. The presence of these metals would account for the 
surface-colouring, which is brought out probably by vegetable 
acids. Whence the alloy comes is not known; but even if imported 
now, it is not improbable that the art of making the ware was dis- 
covered when a local source was known. 

In Colonel Yule’s Glossary of Anglo-Indian Words this ‘bidri”’ 
alloy is described as being a kind of pewter, containing one-fourth 
of copper; and he adds that a short description of the manufacture 
is given by Dr. George Smith, in the Madras Lit. Soc. Journal, 
N. 8., i., pp. 81-84, and that the ware was first described by 
Heyne in 1813. Possibly one or other of these authors, whom I 
cannot now refer to, may give some information as to the source 
from whence the metal was obtained; but that the true ‘“ Bidri” 
of to-day, of which we have examples here in the Museum, con- 
sists mainly of zine cannot be doubted. 

It has been suggested by General Cunningham’ that the alloy 
of copper and nickel of which the Bactrian coins, found so abun- 
dantly in the Punjaub, were made, was imported from China. He 


1 Journal of the Chemical Society, April, 1882. 
2 Numismatic Chronicle, 1873 (8), 18, N. S., No. li. p. 187. 


326 Scientific Proceedings, Royal Dublin Society. 


thinks it possible, also, that the ‘‘ Indian brass, as white as silver,” 
mentioned by the poet Krinagoras, a contemporary of Strabo, and 
the ‘‘ white iron,” of which 100 talents were presented, by the 
Oxydracesw and Malli, to Alexander, at the junction of the five 
Punjaub rivers, may both have been Chinese alloys of nickel. 
With reference to the latter, I venture to suggest that it may have 
been Indian steel, or so-called woots,! which we know in the earliest 
times was a substance considered worthy of being presented to 
kings. Indian white iron, as contrasted with black iron, was men- 
tioned by Homer. Rather than suggest that this Indian white 
iron, supposing it not to have been steel, was not the produce of 
India itself, I would name two other alternatives—one being that 
it was zinc, or an alloy of that metal, derived from the above- 
described mines; secondly, if it really was an alloy of nickel, I 
think it just barely possible that both it and the material of the 
Bactrian coins may have been derived from certain mines in Raj- 
pootana,? where traces of nickel are known to exist, together with 
cobalt, the latter being worked to a small extent to the present 
day. That an extensive trade existed between China and India in 
very remote periods is, as already mentioned, a well-established 
fact, and my object in referring to the matter is to show the possi- 
bility of the above-named materials having been obtained in 
Indian mines, as that is an aspect of the question somewhat over- 
looked hitherto. 

China.—In the early centuries of our era a western carrying 
trade by the Chinese was continued from some unknown earlier 
period. It extended as far westwards as the Persian Gulf, and to 
this trade, in the first instance, may be attributed the introduction 
of zine and its combinations from China into Europe. Subse- 
quently, though there is a record of Chinese vessels visiting Ormus 
in the 1ldth century, it became contracted, and the Chinese fleets 
ceased to go beyond the ports of Ceylon and those of the coast of 


' Its Sanscrit name was vag-ra, a title also applied to thunderbolts and diamonds, 
in the same way that the term Adamas appears to have been used. It has been 
recently shown by Colonel Yule (Glossary), that wootz is in reality not the name of steel 
in any Indian language. He attributes its origin to a clerical error, or misreading, 
for wook, representing the Canarese ukku, steel. It first appears in a Paper, by 
G. Pearson, M. D., in Phil. Trans. for 1795. 

® Keonomie Geology of India, 324-326. 


Batt—-On Zine and Zine Ores. Oo 


Malabar, where they met the fleets of the various nations—at first 
Phoenicians, Greeks, Romans, Arabs; afterwards Portuguese, 
Dutch, and English, which successively had possession of the com- 
merce. 

Now, although I have shown that an actual source of zinc ex- 
ists in India, and was possibly worked long before the 17th cen- 
tury, it is undoubtedly the fact that much of the zine which 
was shipped by the vessels of these various nationalities at Indian 
ports had been first brought from China to be bartered for Indian, 
or, it may have been, Huropean commodities. Hence it is not 
always safe to assume that the articles, though shipped at Indian 
ports, and bearing their names, perchance, or other names of Indian 
origin, were really products of India itself. 

As examples of the confusion which has arisen from similar 
causes, | may quote the case of two localities where diamonds were 
obtained as merchandise, with the result that the countries in 
which they were situated often appear enumerated, erroneously, 
as producing diamonds themselves. Thus, Ceylon’ is spoken of as 
affording diamonds, and the report, though perhaps partly due 
to the false diamonds which are there made of white sapphires 
and zircons, is probably mainly attributable to the fact that dia- 
monds brought from Masulipatam, and other parts of the Coro- 
mandel coast of India, were on sale there. Similarly, the diamonds 
purchased by traders in Malacca, and other older ports of the Ma- 
layan peninsula, were in all probability received first from Borneo, 
and to some extent, perhaps, from India too, just as it is possible 
that Borneo may also have contributed to the Ceylon supply. It 
should be added, however, that the name Malacca was used in the 
time of Linschotten? for Borneo, and hence much confusion by 
subsequent writers, as I shall explain on some future occasion. 

To follow up all the information now available as to the oc- 
currence of zinc ores in China would involve a very considerable 
amount of space, and its treatment here would not precisely belong 
to the specific object at present in view. 

An early account? of the process followed in the manufacture 


1 By Kazvini, in Ajaib-al-makklakat. See J. A. 8. B., vol. xii. p. 632, and many 
other authorities. 

2 J.e. the end of the 16th century. 

3 Sir G. Staunton’s Lord Macartney’s Embassy to China, 1747, vol. iii. p. 382. 


328 Scientific Proceedings, Royal Dublin Society. 


of zinc in China may, however, be quoted :—“ Tw-te-nag (i.e. the 
name by which it was known in India) is, properly speaking, zine 
extracted from a rich ore or calamine. The ore is powdered and 
mixed with charcoal-dust, and placed in earthen jars over a slow 
fire, by means of which the metal rises in the form of vapour in 
a common distilling apparatus. The calamine from whence this 
zinc is thus extracted contains very little iron, and no lead or 
arsenic, so common in the cadmium of Europe, and which ex- 
traneous substances contribute to tarnish the compositions made 
of it, and prevent their taking so fine a polish as the peh-tung of 
China.”’ 

Colonel Yule, in his Glossary (Art. Tootnague), quotes a number 
of authorities who mention this substance as being an article of 
trade from China to India. He points out that the name tootnague 
is not only applied by the natives of India and in commerce to the 
peh-tung, or white copper of the Chinese, but that, like spelter, it is 
apphed loosely to zine or pewter (peh-ywen, or white-lead of the- 
Chinese). 

He also quotes the following, which, for convenience of refe- 
rence, are inserted here :—“ M. Joubert’ of the Garnier Expedition, 
came to the conclusion that the Chinese peh-tung was produced (in 
Yunnan) by a direct mixture of the ores in the furnace.” And 
“ Wells Williams’ says, ‘ The peh-tung argentine, or white copper 
of the Chinese, is an alloy of copper 40°4, zine 25-4, nickel 31°6, 
and iron 2-6, and occasionally a little silver: these proportions are 
nearly those of German silver.’” Further information is to be 
found in the work by St. Julien and P. Campion, quoted below.* 

The following glossary is not exhaustive, as there are many- 
named combinations mentioned by Savot and other early writers, 
into the nature of which I do not propose to enter at present. 
Savot’s work, especially, contains some interesting information on 
the subject. 


1 Voyage de Exploration, ii. 160. 
2 Middle Kingdom, Kd. 1883, 19. 
3 Industries Anciennes et Modernes de l? Empire Chinois, 1869, p. 75. 


Batt—On Zine and Zine Ores. ' 329 


GLOSSARY OF SOME ORIENTAL AND OTHER TITLES USED FOR ZINC 
AND ITs ALLOYS. 


Bidar, Bidri (Hindustani).—This is described by Forbes (Dict.) 
as the metal of which hukkas are made (at Beder). It has been 
shown by Dr. Flight’s analysis, quoted on p. 325, to consist prin- 
cipally of zinc. Curiously enough, Forbes gives no name directly 
for zinc in his dictionary. askat he names as a variety of 
“bidar.” An article on ‘‘bidri” will be found in Colonel Yule’s 
Glossary, as stated on p. 320. 

Birinj, or Pital (Hindustani).—According to the Ain-1-Akbari, 
this metal (brass) is of three (? two) kinds: one kind is malleable 
without being heated in the fire, and it is made of two seers of 
copper to one seer and a-half of rotutia. The other kind is not 
malleable, and it is used in casting; this is compounded of two 
seers of copper and one seer and a-half of rotutia. ‘The propor- 
tions being identical in each case, the translator has probably made 
a mistake (see Gladwin’s ed., vol. i. p. 41:) 

Cadmia (Latin).—The name “ cadmia”’ seems to have been ap- 
plied by Pliny to several ores containing zine, from which brass was 
made, and also to the furnace products, whether of calcination or 
sublimation, found when ores containing zine were roasted. In 
some measure it therefore bore the same signification as calamine, 
but it covered a wider range, being applied to ores which contained 
no calamine, but which, when roasted, produced the furnace cala- 
mine (see Beckmann, Hist. of Inventions, Art. Zinc.) 

Oalamine.—See for suggested origin of this name the Chinese 
“* Vu shih,” p. 831. By some authors the name is still applied to 
the carbonate (Smithsonite), but Dana advocates its being re- 
served for the hydro-silicate. 

Calen, Calaem, Calay (Hin. Kaia’i, i.e. Tin).—Under one or 
other of the above names authors have sometimes apparently re- 
ferred to zine; but these titles are, strictly speaking, corruptions of 
the proper name for tin. And in some cases it is doubtful whether 
the writers merely applied the wrong name to a substance which 
was either zine or pewter, or gave the right name to the substance— 
tin—which they thought was a different metal, as it was some little 
time after Indian tin reached the markets that its identity with 


330 Scientific Proceedings, Royal Dublin Society. 


the European tin, which had been imported into India by the 
Greeks and Romans, &c., came to be fully realized. 

Hasht Dhat (Hindustani) (lit. “eight metals”)—as described 
in the Ain-i-Akbari, consists of a mixture of gold, silver, copper, 
tin, iron, lead, rotutia, and kanseh, the last being a kind of 
bronze, consisting of copper and tin in the proportions of 4: 1 
(see Gladwin’s ed., vol. i. p. 40). 

Khar sini (Arabic) (= Alkali of China) is the name given by 
Kazvini to zine in the 13th century, according to Newbold (see 
J.A.S. B., vol. xi. p. 656). 

Pital (Hin.).—See Biri. 

Rotutia.—In the Ain-i-Akbari this is enumerated as one of the 
seven known metals, the others being gold, silver, copper, tin, iron, 
and lead. ‘The translator, in a footnote, calls it ‘a kind of native 
pewter.” As elsewhere mentioned, Abdul Fazl includes brass 
(and rowey, an alloy of copper and lead) in the list of metals 
obtained by washing in the rivers of Subah, Lahore (Gladwin’s 
Ed., vol. i. p. 40, and vol. i. p. 109). Zutia, according to Colonel 
Yule (Glossary), is the Persian for oxide of zine, and is the base of 
the word Tootnague, q. v. 

Spelter, Spiauter, Speauter, Spealter, Speltrum.—According to 
Beckmann, this word came to us, with the commodity, from India; 
but the derivation of the word seems doubtful. “Spelter” is at 
present used vaguely for zine and pewter, and as such appears in. 
the ordinary commercial trade returns of India. 

Teou-shih? (Chinese).—This name of a metal occurring at 
Tseh-kia (¢.e. Takka, on the Chenab River, in the Punjab) is men- 
tioned in the Si-yu-ki, a Chinese work, compiled in a.p. 646, and 
of which an edition has recently been edited by Mr. Samuel Beale, 
-who says (p. 165): “The ¢eou-shth, of which such frequent men- 
tion is made by Hieun Tsiang, is said to be a compound of equal 
parts of copper and calamine” (see Julien). Medhurst (Dict.) 
suggests that it is native copper, which might seem not improbable, 
except that it occurs in some of the lists together with copper 
(teow). 

Tomback (Hindustani).—This is a variety of brass formed of 
zinc and copper. At one time it was regarded as being of more 
value than gold. It was imported from Indo-Chinese countries. 
Colonel Yule, in his Glossary, gives several quotations as to its uses 


Batu—On Zine and Zine Ores. ool 


in Java, Borneo, and Siam. The terms pinchbeck and prince’s- 
metal appear to be applicable to the same compounds as tomback. 

Tootnague (Hindustani).—Colonel Yule (Glossary) divides the 
meanings attached to this name under two headings, one being 
equal to the peh-tung of the Chinese, the composition of which is 
given on p. 828 ; while the other is a loose application to either zine 
or pewter, corresponding, therefore, with the common commercial 
and very vague term “spelter.”’ According to Beckmann, it was 
_ applied to a mixture of tin and bismuth. This was probably when 
tin from the Straits was first introduced to European commerce by 
the Portuguese, in the 15th century. Calaem, which was also: 
used, was the more correct title. 

The word is derived from the Persian tutia, an oxide of zine, - 
a title which is commonly used now in European works on 
Materia Medica for the artificial oxide. 

Yu-shih (Chinese), which is mentioned, as well as ¢eou-shih, in 
the Si-yu-ki, a Chinese work compiled in the year a.p. 646, is 
considered by Medhurst to be calamine, used in the formation of 
brass. Mr. S. Beale, who suggests its identity with the cadwia of 
Pliny, says that it was possibly called calamine from the name of 
a port Calamina, at the mouth of the Indus, from which circum- 
stance the Chinese described it as coming from Po-sse (7. e. Persia). 
I have not been able as yet to trace the name Calamina on the 
Indus; but Calliana—a name for a port in Bombay—is mentioned 
by Sopater (a traveller of the middle of the 6th century) as a place 
where brass was to be obtained (vide Sir Emerson Tennant’s Ceylon, 
vol. 1. p. 545). 


[) B32hsq 


XXVIIL.—ON THE EXISTING RECORDS AS TO THE DIS-— 
COVERY OF A DIAMOND IN IRELAND IN THE 
YEAR 1816. By V. BALL, M.A., F.R.S., Director of 
the Science and Art Museum, Dublin. 


[Read, April 16, 1883.] 


[From the above given date it will be seen that nearly four years have elapsed 
‘since this Paper was read. The delay in its publication has been due to the fact 
that I was desirous of obtaining some further information on the subject, and, if 
possible, of availing myself of some opportunity for making a personal examination of 
the locality where the discovery is stated to have been made. Although up to the 
present I have not obtained any additional information, and have been unable to make 
the projected examination, I have been led to delay the publication no longer, as it may 
direct attention to the subject, and so lead to the required information being acquired. 
Moreover, inquiries have been recently addressed to me as to what the facts of the case 
really are. Imperfect, and it must be said inconclusive, as they appear to be, they 
are, therefore, now recorded for future reference. ] 


For some time I have been engaged in the collection of ma- 
terials for a general correlation of the diamond-bearing deposits 
throughout the world, and have already amassed a considerable 
amount of information on the subject. Regarding some localities, 
however, the accounts are geologically defective, and I must defer 
for the present attempting to draw up a general statement of the 
facts. In the meantime, however, I would direct attention to a 
record of the discovery of a diamond in Ireland, as the subject 1s 
likely to prove of special interest here. 

In Karl Ritter’s Erdkunde Asien (vol. vi., published in 18386) 
-I first met with the statement that a diamond had been dis- 
covered in Ireland. Subsequently I found it repeated by several 
different writers, and quite recently I have been enabled to con- 
sult John Murray’s work on diamonds, which was published in 
1831, where the fact appears to have been first recorded. The 
passage is as follows :'—‘“ A diamond has also been found in Ire- 
land, in the bed of a brook flowing through the district of Fer- 
managh. It possesses a red tint, and was brought to a lady 


1 Murray, On the Diamond, p. 30. London, 1831. 


Batt—On the Discovery of a Diamond in Ireland. 333 


resident there by a little girl who said she had picked it up in the 
bed of the brook. The bearer was rewarded with sixpence by the 
lady, who had been in the habit of collecting pebbles, &c., from 
the rivulet. This rough diamond was afterwards submitted by 
the lady to Mr. Mackay, an eminent jeweller of Dublin, who: 
pronounced it to be a diamond; and not long after the opinion 
of the late Mr. Rundell of Ludgate Hill was obtained, who valued 
it as a diamond worth twenty guineas in its then rough attire. 
On ascertaining this the lady issued a notice desiring to see the. 
girl again, but she never afterwards made her appearance, perhaps. 
fearful to lose the sixpence, for it appears that even this remunera- 
tion was only granted conditionally. We received our information 
in person from the Rev. Dr. Robinson, of the Royal Observatory 
at Armagh, a gentleman of high scientific attainments, who had 
the gem in his possession, and was well qualified to judge.” 

Before meeting with this passage I was told by Lord James 
Butler that the diamond was still in the family of Sir Victor 
Brooke, to whom I accordingly wrote, and he kindly favoured me 
with the following reply, which differs from Murray’s account 
only in so far as regards immaterial points, such as the names of 
the jewellers who handled the stone. But in order that the 
evidence should carry conviction as to the original matrix of the 
diamond having been in the rocks of the neighbourhood, further 
proof as to the actual position and circumstances with which it was 
found seems desirable. I am led to make this remark since I have 
twice seen specimens of fossil bones obtained from fishermen’s 
houses in Ireland, which were said to have been dragged up in the 
nets, but which, if they had not first been dropped from vessels 
into the sea, were, probably, brought from far distant localities by 
some travelled friends of the fishermen. 

Sir Victor Brooke’s letter is as follows: —“The diamond was - 
found in the year 1816 in the Colebrooke river (which takes its 
rise in the mountains between Monaghan and Fermanagh,’ and 
flows into upper Lough Erne). It was brought to my, grand- 
mother, Lady Brooke, by a little girl who had been searching for 
pearls. Lady Brooke placed it in her inkstand, where my father, 
who had just returned from Brazil, observed it by chance. He 
was struck with it, and said he suspected it to be a diamond, and 
took it up to West, the jeweller, in Dublin. West pronounced it 


334 Scientific Proceedings, Royal Dublin Society. 


to be certainly a diamond. My father then took it to Storr and 
Mortimer, who confirmed West’s opinion, and it was set in Wick- 
low gold either by West or Storr and Mortimer. It is now an 
heir-loom in my family. It is a nice diamond, not quite so large 
as a swan-shot; its only flaw being that it is slightly tinged with 
yellow. There can be no doubt whatever about the authenticity of 
the story.” 

The rocks traversed by the Colebrooke river, in its upper 
reaches, consist of beds referred to the Old Red Sandstone, and ap- 
parently the Silurian formation is also represented close by. Now, 
excepting South African localities, it would seem that the original 
matrix of the diamond, in most of those countries where it is 
found, is in rocks of these ages or somewhat older. It is true that 
in Borneo both diamonds and gold are found in tertiary deposits ; 
but there can be httle doubt that neither the one nor the other 
originated in them, but were derived from older paleeozoic rocks, 
In India, too, the diamonds are generally found in diluvial de- 
tritus, which is, however, largely made up of materials obviously 
derived from rocks of possibly Devonian or Silurian age. 

In Brazil, according to a lately published account’, the mines 
at Grao Mogol and other localities are in a bed of paleeozoic age, 
and at Parana they occur in Devonian sandstones and conglo- 
merates. Mr. O. A. Derby, the writer of this account, considers 
that the diamonds, like the pebbles with which they are associated, 
are all of detrital origin. But at Sao Joao the diamond is believed 
to occur in its original matrix, namely, a vein of quartz called 
barro, now decomposed, but containing iron and tourmaline. This 
vein traverses unctuous schists and itacolumites, which are believed 
to be of Cambrian age. 

Thus, in so far as the age of the rocks goes, there is sufficient 
resemblance to the conditions of diamond occurrence in other parts 
of the world, for saying that there is no inherent improbability in 
the supposition that the diamond which is the subject of this 
notice may have originated near the spot where it is stated to 
have been found. ' 


1 American Journal of Science, February, 1882. 


s838 


_XXIX.—AN EXPERIMENTAL METHOD OF DETERMINING 
MOMENTS OF INERTIA. By GERALD STONEY, B.A. 


[ Read, December 15, 1886.] 


Or the integrals which are found to be useful to engineers, pro- 
bably that which is most frequently required is the moment of 
inertia of a plane round an axis in the plane— 


[= J y°da, 


where y is the distance of an element of area da from the axis 
round which the moment of inertia is to be taken. On the value 
of this moment of inertia depends, among other things, the caleu- 
lation of the transverse strength and deflection of beams; of the 
strength of long pillars; of the distribution of the pressure on the 
foundations of retaining walls and abutments, &c. In all such 
problems it is necessary to determine the moment of inertia of the 
cross-section ; and where this is of complicated form the calculation 
is often difficult, so that it would be a boon to engineers to have 
some simple experimental method of arriving at the result. Even 
where the moment of inertia is determined by calculation, it is 
often useful to have an experimental method of checking the cor- 
rectness of the work. 

The following method of determining the moment of inertia 
occurred to the author when engaged in employing the graphical 
method of investigating the distribution of pressure along the over- 
hung bearing of a shaft. In this method ordinates being erected 
proportional to the pressures at various points along the bearing, the 
centre of gravity of the figure so formed is a point on the line 
of pressure. In the analytical method the same result would be 
reached by the help of a moment of inertia, and the comparison of 
these two methods suggested the following experimental way of 
determining moments of inertia :— 

Cut from the pillar, of the section of which we want to find 
the moment of inertia, or from a model of it, a parallel slice S, 
between two cross-sections, and a wedge W between a cross-section 


336 Scientific Proceedings, Royal Dublin Society. 


and a sloping section, intersecting along mn, a line parallel to the. - 
axis round which the moment of inertia is to be taken. This. 


latter, in nearly all the cases required by engineers, is a line 
passing through the centre of gravity of the cross-section. 

Balance S and W on knife edges, and so determine y, the 
distance of the centre of gravity of S, and Y, the distance of the 
centre of gravity of W, from mn. Then will the moment of 
inertia of the cross-section round mn be 


= Ava 


where A is the area of the cross-section. From this it at once- 
follows that the moment of inertia round an axis parallel to mn 
through the centre of gravity will be 


I= Ay(¥-7). 


This last is the quantity required in engineering problems, and, to- 
determine it, it is only necessary to measure Y and y as above, and 
to determine A, the area of the cross-section. 

To prove this—Let y be the horizontal |distance "of any point 
from mn. Let g be the breadth of the section at that distance 
from mn. Let A be the area of the cross-section. Let V be the 
volume of the wedge W. Let a be the angle of the wedge W. 
Let y be the distance of the centre of gravity of the cross-section S 
from mn. Let Y be the distance from mn of the centre of gravity 


Sronsy—On a Method of Determining Moments of Inertia. 387 


of the wedge W. Let J’ be the moment of inertia of the cross- 
section round mn. Let I be the moment of inertia round a line 
parallel to mn, through the centre of gravity of the cross-section. 
- Then will 


T = f sy'dy. ey 
Again, VY = tana f2y'*dy, 
which, by (1), = tanal’. (2) 
Also V = tana feydy = tan aAy. (3) 


From (2) and (3) we get 
JE SANG 
And since, by a well-known theorem, 
I’ =I+ Ay, 


it follows that the moment of inertia round a line parallel to mn 
through the centre of gravity of the cross-section will be 


I= Ay(Y-¥y), 


which is the theorem to be proved. 

In order to find the positions of the centre of gravity of the 
sections, I have found it convenient to use a table, levelled, and 
with a row of points standing in a straight line, and projecting 
4+inch. The section is then balanced on these points, and when 
the position is found at which it is exactly balanced a slight pres- 
sure, if the section is not of hard material, drives the points into 
the section, and then with a straight-edge a line over which the 
centre of gravity les can be drawn. A sharp knife-edge is in 
some cases more convenient than a row of points. The edge of 
the wedge is to be made parallel to the knife-edge, or row of 
points, and to facilitate this adjustment it will be found convenient 
to draw upon the table a number of lines parallel and perpendicu- 
lar to the row of points. 

With wooden models, made with ordinary care, I found that 
the moments of inertia by experiment and calculation did not in 
any case differ more than 2 per cent., and were generally correct, 
to 1 per cent. This for almost all engineering purposes is of 


quite sufficient accuracy, and in fact is, wherever the section is of 
SCIEN. PROC., R.D.8.—VOL. V. PT. V- 2A 


308 Scientific Proceedings, Royal Dublin Society. 


irregular shape, of greater accuracy than can be obtained by caleu- 
lation, unless great detail is gone into. Thus, in calculating J for 
an =o plate girder, the ordinary approximate method (in which a 
sixth of the web is added to the flanges) gave for the moment of 
inertia 

I = 806:1. 
A yery carefully detailed calculation made 

I = 852°0, 


showing that the approximate method erred by 5:4 per cent. My 
experimental method gave with a wooden model 


T = 8569, 


which is only 0°57 per cent. out. This is one of several examples 
which show that the experimental method here recommended gives 
in complicated cases much closer results than the methods of caleu- 
lation which are practically used by engineers. 

It should be observed that the wedge need not be one which 
comes to an edge, but may be of a truncated form. In all cases 
the line mn, from which Y and 7¥ are to be measured, is to be the 
intersection of the faces of the wedge, and in this case lies outside 
the pillar, instead of being a tangent to it. However, the nearer 
to the pillar that it can be conveniently placed the greater will be 
the accuracy of the determination. Of course the surfaces of the 
wedge must be flat, and the model of the pillar out of which it is 
made of uniform section and density. mm may have two positions, 
since two lines can be drawn, touching the pillar, and parallel to 
the axis round which the moment of inertia is wanted. It is 
‘advisable to place it at the side of the pillar which is the broadest, 
if there is a difference in this respect. 


Leo. ] 


XXX.—NOTE ON A BRILLIANT METEOR SEEN AT STRAS- 
BURG ON THE 15ta OF AUGUST, 1886. By 
J. EMERSON REYNOLDS, M.D., F.B.5. 


[Read, December 15, 1886.] 


On the evening of the 15th of August last I happened to be at 
Strasburg, Alsace, and observed the fall of a meteorite which 
emitted a brilliant light in its passage through the atmosphere. 
The colour of the light was peculiar and suggestive; hence this 
short note on the phenomena. 

At the time the meteor was observed to fall the sun had set, for 
it was five minutes before eight by local time; the sky was cloudless, 
and the atmosphere beautifully clear. The meteorite seemed to 
enter the atmosphere from the west, at a point which appeared 
equidistant from the zenith and horizon, my post of observation 
being the verandah of the Hotel National, which is on the side of 
the large Platz opposite the new Railway Station. The meteor 
seemed to fall directly over the main portion of the station, which 
was almost exactly due west of my position, and the path of the 
meteor was slightly inclined to the horizon, tending south. 

The light was very bright, and, as often observed in these 
meteoric flashes, was greenish; but the impression it produced on 
eyes practised in observing flame colouration was similar to that 
caused by a boracic acid flame, rather than by one whose colour was 
due to copper. 

I am well aware that copper has been found in some meteorites, 
whereas boron has not been detected in any of those whose analyses 
I have seen. On the other hand, the presence of a small quantity 
of boron might be easily overlooked unless very careful search for 
it were made; moreover, carbon and silicon in various states of 
combination have been found in meteorites, and boron is so nearly 
related to both these elements, that its occurrence in meteorites is 
certainly not improbable. 

I hope, then, that in any future analyses of meteorites the pos- 
sible presence of boron may be kept in view, and search made for | 


the element in these strange wanderers from interstellar space. 
2A2 


[ 340 ] 


XXXI.—OLDHAMIA. By G. H. KINAHAN, M.R.1.A., Ere. 
[Read, December 15, 1886. ] 


THE organic origin of Oldhamia has been disputed before now: 
even at the present time some of the American and Continental 
geologists seem to dispute it. Such authorities, however, as Forbes, 
J. R. Kinahan, Harkness, and Baily, have carefully examined it, 
and I have accepted their opinions; but at the same time no one 
is infallible, and there may be a possibility, although, to my mind, 
an improbability, that they may be wrong. 

As the subject is of interest, I propose to put forward all facts, 
as far as I know them, in connection with the occurrence of Old- 
hamia, some of which appear to me conclusive that it must be of 
organic origin, while others may suggest that it may be a mineral. 
structure. 

At one time it seemed to me to be remarkable, that very often 
the Oldhamia is better developed in shales near an intrude of 
Quarts-rock than elsewhere. ‘This, however, on going over the 
evidence, now appears to be more apparent than real. 

In the west portion of Ireland the Cambrians are so much 

altered that all organic remains are obliterated; it is, therefore, 
only in eastern Ireland that these can be found. The localities for 
Cambrian or supposed Cambrian in this portion of Ireland may 
therefore be given beginning to the north, and in connection with 
each, stating the peculiarities. 
' In the north of the Co. Down, bordering Belfast Lough, are 
green and purple rocks that appear to be unconformable with the 
associated Ordovician rocks: these rocks are so like those of Bray 
Head that DuNoyer classed them as Cambrians. In them Odd- 
hamia has not been found; nor as far as I am aware are there in 
connection with them intrudes of Quartz-rock. 

In the Co. Longford, to the east of Granard, there are also 
more or less similar rocks that seem to be overlaid unconformably 
by the associated Ordovician rocks. The character of these rocks 
led Foot and myself to suspect they must be the representatives of 


KinanHan—On Oldhamia. 341 


the Bray Head Cambrians. In these no Oldhamia has been 
found, although we searched them very carefully; nor is there any 
intrude of Quarts-rock. 

In Howth promontory, Co. Dublin, Wyley classed the rocks as 
‘Cambrians, while subsequently J. R. Kinahan found at Puck 
Rock Oldhamia antiqua.(?) The specimens I found in this 
locality were on a smooth pale-green phylitic shale. I do not 
think there is an intrude of Quartz-rock in connection with this 
special locality ; but elsewhere in Howth there are different m- - 
trudes of Quartz-rock, and in connection with them there are not 
any known localities for Oldhamia. 

At Bray Head, Co. Wicklow, Oldhamia (radiata and antiqua) 
occur in numerous places. Those with which I am the more inti- 
mately acquainted are more or less in connection with the intrudes 
of Quarts-rock ; some places, however, are not so. 

At Greystones, south of Bray Head, Oldhamia has also been 
found; but my knowledge of these rocks is too scant to mention 
more about them. According to the map in this neighbourhood 
there are intrudes of Quarts-rock. 

In Carrick Mountain, south of Glenealy, is the locality where 
Oldhamia was first found by Flanagan. Here it occurs as O. 
vadiata, O. antiqua, and O. discreta, the latter being an intermediate 
form between the others, to which attention was first drawn by 
J.R. Kinahan (Zrans., Royal Irish Academy, vol. xxiii., p. 547). 

At Flanagan’s locality the Oldhamias occur in purplish shales 
like those of Bray Head, and in phylitic pale-greenish shales, the 
best marked specimens being in the latter. This locality is inti- 
mately connected with intruded cakes of Quarts-rock. 

At Roney Rock, south of Courtown Harbour, Co. Wexford, 
alongside an intrude of Quarts-rock, in a thin bed of red shale, 
there is O. antiqua. 

Farther south along the Wexford coast, at Cahore bathing- 
place, O. radiata occurs in a purple bed, like those of Bray Head ; 
while at Cahore Head, O. antiqua occurs sparingly in a light-green 
phylitic shale. Here there are no intrudes of Quarts-rock. 

Going still further southward, to the south-east and south of 
Bannow are other Cambrian rocks. These I have very carefully 
examined. Along the south coast the Oldhamia was only found 
in reddish, or slightly purplish, beds; the three forms, O. radiata, 


342 Scientific Proceedings, Royal Dublin Society. 


O. antiqua, and O. discreta, occurring, but the last are those more 
generally found. In some places O. radiata occurred in lenticular 
pockets of limited extent; outside of which, although the rocks 
were exactly ocularly similar, not a trace of Oldhamia could be 
found. In other places O. antiqua or discreta might be mixed in the 
shales, but in general they were confined to thin beds, often not 
more than the eighth of an inch in thickness; and in this thin 
bed, and in no other, could the Oldhamia be found. Some of such 
thin beds I traced for nearly a furlong. These beds, as also the 
associated Ordovician rocks, have in them intrudes of Quartz-rock. 

On the west coast of Bannow, close to the fault boundary of 
the Ordovician, in one four-inch bed of green shales, Oldhamia 
occurs sparingly. Here there are no intrudes of Quartz-rock. 

In the foregoimg I have specially mentioned the intrudes of 
Quartz-rock, because at one time I suspected there might be some 
connection between them and Oldhamia; but the above records 
seem to disprove such an idea. An Oldhamia bed has a certain 
look ; and, after hammering bed after bed along the Wexford coast, 
I came to learn the exact appearance of those in which I would 
probably find Oldhamia, let the colour be reddish, purplish, or 
greenish. 

Forbes, J. R. Kinahan, and Baily, from their investigations, 
come to the conclusion that Oldhamia has an organic origin; but 
my knowledge of such organization debars me from giving a posi- 
tive opinion in their favour. Others say it is not organic; this 
also, my knowledge leaves me incapable of refuting. I can, how- 
ever, legitimately take an intermediate ground. This is not 
exactly easy to name; but perhaps it may be called lithological 
evidence, it referring not so much to the fossils as to the rocks in 
which they occur; but before doing so I may refer to the forms 
of Oldhamia, and the more or less similar mineral forms. 

Oldhamia is said to have a more or less similitude to some of 
the mineral markings on beds surface, joint planes, and other 
similar surfaces in rock structure. I have, indeed, seen some 
dendritic markings somewhat like O. radiata, but never any that 
I would mistake for it, as the points of the dendrites have an 
angular termination quite dissimilar to those of the Oldhamua. 
As to the impression of O. antiqua and O. discreta, I have never 
seen any surface mineral at all like them. Oldhamia, as it at 


- Kinanan—On Oldhamia. 343 


present is found, may be a mineral, and may even in part have 
lost its original form; but I contend that originally it was an 
organic form, but now mineralized, or having on the original form 
minerals built up. This subject was treated on nearly a quarter 
of a century ago in a Paper by our member Mons. A. Gages, 
who pointed out, in reference to the graptolites in some Ordovician 
black shales, that they were not only mineralized, but that at 
certain attractive places, such as points, bunches of crystals had 
accumulated. It appears scarcely necessary to point out that in 
some rocks, such as the Lias Coal-measure, &c., fossils are per- 
fectly mineralized ; while in others, such as the Cretaceous, they 
are not only mineralized, but have formed a nucleus round which 
foreign matter has accumulated. 

If Oldhamia is a mineral structure, why does it occur under such 
peculiar circumstances? It has only been found in the Irish 
Cambrians, and in them it is confined to very limited strata; often 
searcely the thickness of your nail, so that only those acquainted 
with its Aabitat can find it. If it is a mineral, why does it not 
also occur in the exactly similar rocks adjoining these thin seams 
or layer, the layer or seam being identical in composition with the 
associated rocks ? 

Exactly similar rocks to those at Bray Head, in which the 
Oldhamia are found, occur in the Cambrians of other places in 
Ireland, and in those of England and America; yet in none of 
these places has it been found. Dendrites occur everywhere if the 
rocks are similar: why, therefore, if O/dhamia is a mineral, is it not 
similarly distributed ? 

Also in various places inside and outside Ireland there are 
rocks all made of identical mineral constituents to those of the Irish 
Cambrians in which the Oldhamia is found. 'The seare of Silurian, 
Ordovician, and Cambrian ages, and in none of them, except those 
of proved Cambrian age, has the O/dhamia been found. If it isa 


1 The late Mr. E. Leeson, Fossil Collector on the Government Survey, and myself 
collected boxes of Oldhamia at Bannow ; yet no one since, except Mr. Clarke, seems to 
be able to find it. At Cahore bathing-place Messrs. Baily, Leeson, and myself, carried 
away a bag full of fossils; yet twice since I was there, and I could not find the bed, 
although I know the exact place where it is. Similarly, Flanagan’s original station 
on Carrick mountain was not known till a few years ago, when it was accidentally 
discovered. 


344 Scientific Proceedings, Royal Dublin Society. 


mineral marking, it appears to me that it ought not to be confined 
to rocks of one formation, but should be common to all similar 
rocks, no matter what their age may be; similarly as we find 
dendrites in rocks of nearly every age. 

As will appear from the first portion of this Paper, I am still 
quite open to conviction; but up to the present time the arguments 
put forward in favour of O/dhamia being of organic origin seem to 
me to be convincing. I therefore submit my views for the con- 
sideration of those who are of an opposite opinion. 


— 
co 
pS 
Cr 

a) 


XXXII.—_NOTE ON A SPECIMEN OF ADULTERATED GUANO 
RECENTLY ANALYSED IN TRINITY COLLEGE 
LABORATORY. By EMIL WERNER. 


[Read, December 15, 1886. 


Axout two months ago I purchased at an establishment in this 
city a sample of Peruvian guano, the idea at the time being simply 
to examine the sample for uric acid, and if found comparatively 
rich in that body to obtain a further supply. The guano, how- 
ever, On examination proved such an unusual specimen as regards 
adulteration and general inferiority that, at the request of Dr. 
Reynolds, I analysed the sample, and now beg to lay the results 
before the Society. With respect to the uric acid, which is a 
constant constituent of all good guanos, it was in this case con- 
spicuous by its absence: not even a trace of it could be obtained 
when operating on four ounces of the guano. 

So considerable was the adulteration, that, before commencing a 
complete analysis of the guano, it was necessary to pass it through 
a coarse sieve, a treatment which resulted in the separation of a 
quantity of foreign matter, in the form of pieces of granite, shells, 
&e., to the extent of twenty-five per cent. of the weight of the 
guano. The composition of the sifted guano is shown in the 
following analysis :— 


Composition oF GUANO, PREVIOUSLY FREED FROM 25 °/, ADULTERATION. 


Sand, 24°36 °/ 

CaO, Seeiioongs 

Fixed constituents |P20;. . c eel 42 Oho a 
= 59°30 °/,, SOs : 5) PROD =I 
20, : ° ° 5°13 as 

MgO and nitrates, . 1°82 °/, 

59-30 °/, 


Moisture, 0 > sss 
Organic matter, . 22°10 °/,, containing nitrogen = 0°02 °/, 
3 


= GUO" o 2S Gesaihaell Mig gp COLI | op - 06 °/, 


‘Organic and Volatile ( 
‘ih 
40°55 °/, Total nitrogen, . 4:08 °/, 


As is seen from the analysis, the amount of insoluble matter 
(sand) is still exceptionally high—nearly twenty-five per cent.: the 


346 Scientific Proceedings, Royal Dublin Society. 


other constituents forming the fixed matter call for little or no 
comment with the exception of the phosphoric acid, which for a 
highly adulterated guano is much above the average; the mag- 
nesium oxide and nitrates, both of which were present only in 
very small quantity, were not directly estimated, the amount 
being determined by difference. A remarkable feature in this 
guano is the nitrogen, which, besides being naturally low, is en- 
tirely present in the form of ammoniacal salts: the minute amount 
of organic nitrogen, ‘02 -per cent., shown in the analysis, is no 
doubt due to partial conversion of the nitrogen of nitrates into: 
ammonia during the ignition with soda-lime in presence of the 
organic matter. 

In order to give a better idea of the extensive adulteration of 
the sample, I append below the calculated composition of a ton of 
the original guano. 


Composition oF A Ton oF OriGinaAL Guano. 


Or eanic matter, 
ali otal nitrogen, 


cwt. lbs. 
Sand, stones, &c. (adulteration), c 6 . ¢ & 
aO Q : 6 0 : 5 é : 1 96 
P05, 2 30 
SOs, 0 37 
K.0, 0 89 
MgO and nitrates 0 32 
Water, 28 

3 

0 

19 


The deficiency here is due to the fact that the calculation is not 
carried beyond pounds, and the ammonia in the guano is calcu- 
lated to nitrogen only. ‘The extensive adulteration in the above 
case is probably the work of the exporters of the guano; never- 
theless the Dublin merchants who supplied it are not without 
blame, on account of either ignorance or carelessness in the selec- 
tion and examination of their own purchase. 


eee 


-XXXIIIL—ON A HYDROSTATIC BALANCE. By J. JOLY, B.E., 
Assistant to the Professor of Civil Engineering, Trinity 
College, Dublin. (Plate VII.) 


[Read, June 9, 1886.] 


Tur Hydrostatic Balance described in this Paper will be found il- 
lustrated on Plate VII., reference to which will enable its principle 
to be the more readily understood. It will be seen from figure 1 
that it consists essentially of a vessel provided with one narrow 
tubulure opening, and suspended so that this tubulure is down- 
ward. Within is a second vessel; this vessel is closed, and is made 
of such shght material that it floats buoyantly in water. 

A fine wire is attached to the lower end of this inner vessel, and 
passes through the tubulure. The tubulure of the outer vessel is on 
a nozzle which, when screwed off, and the vessel turned up, enables 
the space surrounding the float to be readily filled with water. 
When filled, and the nozzle replaced, the vessel is hung up, as in 
the figure, with the tubulure downwards. The diameter of the 
tubulure being only some 8 mms., there is perfect security 
against outflow: indeed the apparatus may be shaken or rolled 
about upon a table with impunity. When the balance is hung it 
is obvious that the inner vessel or float, in virtue of its buoyancy, 
will be urged to ascend within the liquid, and if, as in fig. 2, we 
hang a pan on the wire, and load weights on the pan, we find that 
we can add weights up to a certain point, when the pan descends 
with the sinking of the float within the vessel. This weight —just 
adequate to cause the pan to descend—we assume for the present 
to be constant, and equal W, suppose. W é is evidently equal to 
the weight of a mass of water having a volume equal to the dis- 
placement volume of the float, less the weight of the float, of the 
wire, and of the pan attached to the wire. We can evidently 
ascertain, now, the weight of any mass not heavier than W. It 
is as if we were using a balance, one arm of which was loaded 
with an unalterable weight W. Thus, we place the substance to 
be weighed on the pan, and add weights till the pan descends. 


348 Scientific Proceedings, Royal Dublin Society. 


At this point we know that a total weight W is in the pan. 
If the added weights amount to w, suppose, then x = W —- w. 
Practically, however, W is a quantity variable with the tem- 
perature of the float and of the water, their densities altering to 
different extents. When, therefore, accurate results are required, 
we cannot assume any constant for the balance, but must determine 
afresh the force W with each determination of w. Or, what is 
the same, we proceed by simply removing # when equilibrium has 
been obtained with x + w, and substituting a weight w,, so that 
equilibrium is again obtained, when w, is the required value of z. 
It is easy to guard against change of temperature in the brief 
interval necessary to effect the successive equilibrations. The 
process of weighing is, in short, the well-known one of substitu- 
tion, and with the usual correction for unequal air displacements 
of the weights, and the substance is accurate to a degree depending 
on the sensibility of the float to indicate a small change of load, 
when the downward acting forces are very nearly in equilibrium 
with the upward acting forces. ‘This consideration, 7. e. the degree 
of sensitiveness possessed by the arrangement, next claims atten- 
tion. 

The system as described is, in principle, identical with the 
Nicholson hydrometer, used as a weighing machine, the latter 
arrangement being supposed inverted while still retaining the 
liquid. But the inversion of the hydrometer introduces this 
important difference, that the stem supporting the pan of the 
hydrometer, a compression member, becomes in the hydrostatic 
balance a tension member, and hence, stiffness being no longer a 
requisite, may be made of extreme fineness, and the retarding | 
effect of the adhesion of the liquid on the wire at its circle of 
" emergence is much reduced. 

If, indeed, we assume the effect of this rillhaston of the surface- _ 
film to increase in direct proportion with the radius of the circle of 
emergence, it would appear—observing that the tensional strength 
of the wire increases proportionally to the square of this radius— 
that the sensibility to a small fraction of the entire load falls off 
only as the square of the carrying capacity or load which the 
balance will bear. There is, in short, reason to expect that, as we 
increase the size and carrying capacity of this kind of balance, 
no diminution of the fractional sensibility occurs, but rather an 


Joty—On a Hydrostatic Balance. | 349: 


increase; the sensibility increasing approximately as the square. 
root of the power of the balance. Thus, if we double the diameter: 
of the wire, the balance will now indeed indicate nothing smaller 
than double the least weight formerly causing displacement; but, 
on the other hand, we may assume a quadrupled carrying capacity. 
This leaves out of consideration the effect of viscosity of the- 
liquid. 

The effect of viscosity will hardly be to reduce the sensibility, 
but rather to render more tedious the use of floats having large. 
displacements. As, however, the tangential resistance to the 
motion of a solid surface, in the act of communicating a shearing 
strain to a liquid, is proportional to the extent of surface, and as this 
area increases at a slower rate than the volume inclosed by it, it 
appears that the tediousness attending operations is, again, not 
fairly assumed to be an attendant disadvantage which increases. 
proportionally with increase of power of the balance The effect is 
indeed, probably, complicated by the presence of currents or eddies. 
in the liquid. 

As regards the effects of solid friction, contact between the 
movable and immovable parts might, indeed, be altogether 
avoided. ‘Thus we might attach the wire externally to a flat 
cantilever, or flat spiral spring, so that it is retained in the centre of 
the tubulure by the horizontal rigidity of the spring, while the 
spring may possess such small vertical rigidity as not to interfere 
with the sensibility of the balance. It will be seen, however, from 
the figures, that this plan is not resorted to. It appears indeed 
unnecessary to do more than guard against contact down the wall 
of the tubulure ; and this is provided for in the little projecting 
collar placed at the point where the tubulure meets the wider 
nozzle. ‘The diameter of the passage here provided for the wire is 
about 1:5 mm.; the tubulure is about 3 mms. in diameter. The 
edge of the collar is sharpened to a knife edge all round, but just 
burnished smooth. With this arrangement, if the precaution be 
taken of using a smooth piece of wire, there appears but little 
retardation due to friction: this, doubtless, is partly due to the 
position of the collar within the liquid, the liquid acting as a 
lubricant. The effect of substituting a collar of burnished agate 
for the brass collar has been tried as in the balance, fig. 2, but 
with hardly appreciable gain in freedom. This little balance (fig. 2) 


350 Scientific Proceedings, Royal Dublin Society. 


is represented in its actual dimensions. The float is a sphere of 
slight blown glass, weighing about 12 grammes, its diameter being 
about 6:3 cms. The outer vessel is of brass, parting, in a screw- 
joint, into hemispheres. or convenience of weighing by replace- 
ment, a double pan of slight brass is attached to the wire. This 
pan, together with the suspending gear, weighs about 11 grammes. 
The suspending wire traversing the surface of the liquid is of brass ; 
its diameter is 0°09 mm. Its breaking strength is 403 grammes: 
the stress it is called upon to bear in the balance does not ordi- 
narily exceed 120 grammes. A suddenly added or removed load 
might, indeed, act to some extent as a live load, and an increased 
stress result. Experience, however, seems to show that the strength 
is ample. 

The balance is protected from draughts and sudden changes of 
temperature by a glass case, from the roof of which it depends, 
hanging freely... The weights are introduced at a half door in the 
lower part of the case. The case needs no levelling screws. 

At 6° C. the load carried in the pan, when equilibrium obtains, 
is 104-660 grammes. <A change of load of 1 milligramme now 
-eauses displacement, and effects the descent or ascent of the pan. 
This balance then estimates the weight of 100 grammes to an 
-accuracy of 100,000. 

I must here observe, however, that working the balance to this 
degree of accuracy needs some care. Where estimation to an 
accuracy of say three milligrammes only is needed no special pre- 
cautions are likely to be required. But with the construction 
shown in the figure for confining the travel of the pan and float 
there would seem to be an amount of adhesion before the pan is set 
in motion, which the small force of one milligramme will some- 
times be unable to overcome. It is seen in figs. 1 and 2 that the 
double-eyed link to which the suspension wire is attached moves 
through—but without contact while moving—an eye which arrests 
its motion ascending and descending, affording it only about one 
-centimetre run. The float thus never reaches either to the top or to 


1 For very delicate work the further precaution of preserving the whole in a 
-chamber not exposed to sudden fluctuations of temperature is, I find, necessary. 
Trouble from this source might doubtless be guarded against in all cases by sur- 
rounding the outer vessel with a non-conducting covering. 


J oLy— On a Hydrostatic Balance. bol 


the bottom of the containing sphere, and adhesion at these points is 
avoided. The arrangement also obviously secures the advantage 
of guarding the fine wire against the effects of a weight erroneously 
- added in excess of the power of the balance: indeed, if care is 
taken in adding and removing weights, the wire remains uniformly 
in the one state of strain. It is thus kept straight and true. Again, 
should the wire break, the descent of the pan is arrested by the eye 
and link. The arrangement, too, renders a slow motion of dis- 
placement very readily observable. I may observe, that the eye 
encircling the link is gapped at one point, to enable the link to be 
removed if desired. The construction of this link is simple, but ne- 
eessitates the exercise of a little care in the process of equilibration, in 
order that the effect of adhesion at the link may be guarded against. 
The process of equilibrating is as follows:—The larger weights 
being added successively in the usual way, the equilibrium, we 
will suppose, determined to 1 centigramme, and the milligrammes 
reached, the 5 is added: if there is no immediate effect we 
grasp the link with the ivory forceps (used with the weights), and 
bring it down to the centre of its run, then release it, and observe 
its motion. It will most probably ascend; but there may have 
been adhesion between the link and eye, and we may find that it 
descends slowly. Its velocity of motion is in either case instruc- 
tive after a little practice, and, as with the chemical balance, will 
enable us to save trials. If the link in the present case very slowly 
descends, we replace the 5 with 4 mers., and repeat the process of 
drawing down the lk. We take care also to close the glass 
‘door while observing the motion. The result will be perfectly 
definite. It will ascend with the 4, suppose; descend with the 5, 
the starting point in each case being the centre of its run. And I 
may observe that it will, in this way, indicate a less quantity even 
than 1 milligramme. Thus recently using this balance with a new 
set of weights, I detected discrepancies in the 1 centigramme 
weights, as compared with the added milligrammes, which, on sub- 
sequently evaluating on a delicate chemical balance, were severally 
found to be ‘7 and °3 of a milligramme. It would, doubtless, be 
easy to arrange, so that the adhesion necessitating these precau- 
tions when weighing with the milligrammes would be eliminated. 
In fig. 3 two kinds of bearing are suggested: one—(a) where there 
is contact at two points; the other, (4) at one point only, when the 


302 Scientific Proceedings, Royal Dublin Society. 


link is at either limit of its run. The last plan, too, would have 
the advantage of starting motion with the suspension wire in a 
central position. 

If delicate weighing is to be carried out on these balances, it is 
necessary to use water that has been carefully filtered, as sediment. 
will settle down into the tubulure, and clog the wire, adhering to it 
as it emerges from the liquid. 

Experiments extending over several weeks showed that there is _ 
no reason to expect that under varying conditions of atmospheric 
pressure bubbles of air would be given off by the water to adhere 
to the float, provided the water is not supersaturated with air in 
the first instance. In my experiments the action, in this direction, 
of the variations of pressure was represented on an exaggerated 
scale under the air-pump to tensions of 50 mms. of mercury. This 
tension failed to withdraw visible bubbles from water previously 
freely exposed for a long period to the atmosphere. What dis- 
solved air was withdrawn probably slowly emanated at the surface. 
The water was contained in a beaker, the float being represented 
by an immersed spherical glass vessel. 

In the balance depicted in fig. 1 there is no provision for the 
effects of variation of temperature: any notable change of tempera- 
ture will, with that construction, result in drawing air into the 
containing vessel, or expelling some of its contents. For occasional 
use, where the balance is necessarily filled and emptied frequently, 
as in travelling, this is of no importance, and will cause no trouble, 
if the precaution is taken of filling it with water appreciably at air 
temperature. ‘The effects of temperature change will, indeed, be 
inconsiderable. Thus, taking the case of concentric spheres of 
brass, the inner displacing 179 grammes (diam. = 7 ecms.), the 
- outer having a diameter of 9 cms., and the intervening space filled 
with water, the effect of 1° C. change is a displacement of 14 cubic 
millimetres of water, about half a drop. The entry of a “ttle air 
obviously does no harm: it simply rises to the top of the vessel, 
and in no way interferes with the truth or capacity of the machine. 
A little expelled water is easily dried off. 


1 Tf the float be made of a substance having a low coefficient of expansion, such as 
glass, and the containing vessel be of material having a high coefficient of expansion, 
as brass, such dimensions may be given to the apparatus that the water space shall, 
with change of temperature, increase at: the rate of expansion of water. In other 


Joty—On a Hydrostatic Balance. 309 


If it be desired, however, to render the arrangement nearly 
permanent, so that the operation of filling need but very seldom be 
repeated, the effects of temperature in expelling water or drawing 
in air must be met in some way. In the balance of fig. 2 this is 
done by providing the expansion reservoir shown surrounding the 
tubulure, and which communicates with the interior of the sphere 
by the narrow tube nearly reaching to the bottom of the reservoir, 
as shown in the figure. The large surface of water exposed in this 
reservoir bears to stand at a level above or below, by a couple of 
millimetres, the surface level of the water in the tubulure, as in the 
well-known experiment on capillarity in communicating tubes of 
very unequal bore. Hence, with rise of temperature the reservoir 
receives the expelled water; with fall of temperature it parts with 
some of its contents, and no water is lost. The annular reservoir 
communicates with the air by a very small perforation, and the 
loss by evaporation is very small. 

To enable the balance to be readily filled, the ring by which it 
is suspended is arranged to screw out of a little tubulure communi- 
eating with the interior. The balance 1s filled in a few seconds by 
screwing out this ring, and immersing the sphere in a vessel of 
water; when no more bubbles ascend through the tubulure, the 
ring is screwed home, while the tubulure is still beneath the surface 
of the water. On withdrawal a little water runs out at the lower 
tubulure, till the head in the reservoir has been syphoned down to 
a position of equilibrium with the surface tension at the tubulure ; 
the head is now still further reduced by applying a little bibulous 
paper to the tubulure, in order to provide for a subsequent rise in 
temperature. 


words, there would be no expulsion of water or entry of air with atmospheric varia- 
tions of temperature. Thus fora spherical float in a spherical chamber, and assuming 
any desirable radius, 7, for the float, let x be required radius of outer vessel; also let 
g, 6, and whe the co-efticients of cubical expansion of glass, brass, and water, equating 
the increments of volume for a rise of one degree— 


2b = rg + (2 — 7) w; 
taking g = 0000025; 6 =0-000054; w=0-00014; 
Ge = ICSE S¢ GE 
But this affords unfortunately rather closely approximating values for x and r, as, for 
example, if 7 = 2°9 ems. (vol. = 100 ccs.), then x = 3:2 cms. Nor can I find materials 


affording much better results. 
SCIEN. PROC. R.D.S.—VOL. V. PT. Ve 2B 


304 Scientific Proceedings, Royal Dublin Society. 


For the purpose of determining the specific gravities of solids, 
IT use a little claw for supporting the substance under water, 
which can be suspended by a fine wire from a hook beneath 
the pan. The substance is first weighed in the pan, the claw being 
attached and immersed in a vessel of water placed beneath. On 
transferring the substance to the claw an increased weight will be 
required for equilibrium ; the increase is obviously the weight of 
displaced water. 

It is observable in the hydrostatic balance that, when the float 
is about to descend, the system is one of unstable equilibrium. 
The descent of the float is accompanied, in fact, by decreased dis- 
placement in the liquid due to the emergence of the wire, the 
effect being similar to that of an ever-increasing downward pull 
upon the float: once started, it tends to descend to its lowest point. 
If we provide a second wire, similar to the emerging wire, ex- 
tending downwards, and dipping into a vessel of water, as occurs 
in the operation of determining specific gravity, the effect is in all 
cases obviously annulled. The correction is, however, with wire of 
the diameter 0:09 mm., quite unnecessary ; the displacement of one 
centimetre of this wire pov ean ne but a small fraction, 0:06 of a 
milligramme. 

I state these particulars at length, as I do not at present know 
of any other weighing machine in which a similar degree of deli- 
cacy may be so combined with the qualities of inexpensiveness and 
compactness, up to any ordinarily required power, as in this 
balance. 


f 355 J 


XXXIV.—ON A SPECIMEN OF SLATE FROM BRAY-HEAD, 
TRAVERSED BY THE STRUCTURE KNOWN AS 
OLDHAMIA RADIATA. By PROFESSOR W. J. 
SOLLAS, LL.D., D.Sc. 


[Read, November 17, 1886.] 


Tue structure known as Oldhamia radiata commonly presents itself 
in the form of discontinuous thread-like ridges radiating from a 
common centre, and lying in the planes of cleavage (coincident 
with the planes of original bedding) of a slate. A hand specimen 
in the collection of Trinity College, Dublin, cut transversely to the 
cleavage planes, shows, however, that the Oldhamia structure is not 
merely superficial, but extends across the cleavage planes into the 
substance of the rock. 

In the hope of throwing further light upon this problematical 
structure, thin slices for microscopic examination were cut from this 
specimen, both parallel and transverse to its planes of cleavage. 
On placing these under the microscope all trace of the Oldhamia 
structure appeared to have vanished. An examination with the 
unaided eye showed, however, that it was still there, presenting 
itself as narrow, undulating, and branching bands of a lighter 
colour than the surrounding matrix: its appearance, however, 
varied in an extraordinary manner according to the direction in 
which it was viewed. Looked at obliquely in a strong light, the 
thread-like bands are brilliantly illuminated, and appear faintly 
coloured with spectral tints; looked at directly, the bands become 
fainter, and are less clearly distinguishable from the matrix. In 
certain positions the slice taken at right angles to the bedding has 
an appearance somewhat suggestive of shot-silk, and from the 
planes of cleavage, markings which somewhat remotely resemble 
in form the dendritic markings of Sutton stones extend into the 
surrounding matrix. These appearances, taken as a whole, suggest 
the presence of some mineral possessing high reflection or refrac- 
tion arranged in more or less parallel planes. 


My friend, Mr. Teall, to whom I submitted the prepared slides 
2B2 


306 Scientific Proceedings, Royal Dublin Society. 


has very kindly sent me the following notes on the mineral charac- 
ters of the slate. By their insertion in this place my concluding 
observations will be made intelligible. 


Bray-Heap SuateE. 


“The main mass of the slate appears to be composed of quartz, 
sericite, and chlorite. 

“The quartz and sericite are so intimately intermixed, and the 
individual constituents are so minute, that it is often extremely 
difficult to make out the boundaries of the crystalline elements in 
consequence of overlapping. The sericite scales are, however, easily 
recognisable by their more intense action on polarised light. They 
give colours when the quartz only polarises in neutral tints. 
When viewed in ordinary light, the sericite appears colourless. 
The scales show a tendency to an arrangement of their flat faces. 
parallel with the planes of schistosity, as may be seen by rotating 
a section at right angles to the schistosity under crossed nicols. 
The greatest effect is produced when the planes of schistosity cut 
the cross-wires at an angle of 45°. The parallel arrangement of 
the sericite scales is, however, by no means rigidly observed. 

“The quartz, so far as it can be examined, gives no evidence of 
a clastic character. 

“The banding in the slate appears to be mainly determined by 
a variation in the amount of chlorite present. Some bands are 
very rich in chlorite, other bands contain only a very small 
amount of this mineral. 

“The chlorite occurs in somewhat irregular scales and scaly 
aggregates. Sections at right angles to the easy cleavage are 
markedly dichroic (rays parallel to the cleavage cracks very pale 
yellow or brown, sometimes almost colourless; rays at right angles 
to the cracks rich bluish-green). 

“In addition to the quartz, sericite, and chlorite, there are nu- 
merous minute spots which appear nearly opaque by transmitted, 
and white by reflected light. With a magnifying power of 500, 
these may be resolved into aggregates of more or less trans- 
parent grains, which resemble the common alteration product 
(leucoxene) after ilmenite. Sometimes these aggregates are seen 
in association with black grains, and it seems probable, therefore, 


Soittas—On a Specimen of Slate with Oldhamia. 308 


that they represent the alteration of ilmenite or titaniferous mag- 
netite. A few scales of hematite also occur in the slides.” 


To this I may add that—(1) some fragments of quartz are pre- 
‘sent in the slate, which I think do undoubtedly show traces of a 
clastic origin; and (2) that a minute crack traversing the cleavage 
planes is shown in one of the slices; it is lined by chlorite on 
both sides, and filled with quartz containing minute scales of 
sericite, and numerous air-cavities, both spherical and crystal- 
shaped. Hematite is also present on the quartz; this shows that 
the formation of chlorite and sericite, and quartz, continued to 
take place even after the cleavage of the slate. 

Examining the slices in the light of this description, one finds 
that the lighter-coloured bands, which correspond to the Oldhamia- 
structure, owe their distinction from the surrounding matrix to 
the presence of an excess of sericite scales; and that the curious 
shot-silk appearances are produced by the local deflections of these 
scales from parallelism with the cleavage planes, into directions 
tangential to curves, which are probably transverse sections of those 
long ridges which, when seen on the exposed surface of a cleavage 
plane, are recognized as the usual form of Oldhamia ; and it would 
appear possible that these ridges are wrinklings of the cleavage 
planes produced during the shearing which led to their formation. 

In addition to these corrugations, a structure resembling false 
bedding, on a small scale, is visible on some parts of the slices. 


essa 


XXXV.—SUPPLEMENTARY REMARKS ON THE PREVIOUS: 
PAPER ON OLDHAMIA. By PROFESSOR W. J.. 
SOLLAS, LL.D., D.Sc. (With Plate VIII.) 


[Read, December 15, 1886.] 


Tue interesting discussion which the observations on Oldhamia,, 
made at the last meeting of this Society, have elicited has induced 
me to offer the following supplementary remarks :— 

1. The phyllades in which Oldhamia occurs consist of laminze of 
mica (sericite), clastic grains of quartz, and chlorite. 

2. The boundaries of the quartz grains are usually concealed in 
the usual thin slices of the rock by the chlorite: on treatment with 
hydrochloric acid, which removes the chlorite, they are rendered 
plainly visible. 

3. The surface of the lamine of the phyllades in which Oldhamia 
does not occur are smooth and even, and in transverse section the 
constituent minerals are found to be arranged in planes parallel to. 
one another, and to the cleavage lamine. 

4.° Oldhamia presents itself on the surface of the laminse when 
it is. present as rounded discontinuous ridges, which are without 
definite boundaries, and have the appearance of fine wrinkles. 

5.” When the phyllade is fractured obliquely to the cleavage 
laminz, the Oldhamia markings are found to extend through the 
rock, as fine ridges or wrinkles, which mark the surface of oblique. 
fracture in a similar manner to those of the cleavage face. 

6. Transverse sections of such phyllades are wrinkled, conform- 
ably to the Oldhamia ridges, in minute undulating folds; the 
‘sericite scales lie with their faces in the surface of these folds, 7.e. 
they are tangentally arranged. The width of the folds, measured 
from crest to crest, is about 0:4 to 0°8 mm.; the Oldhamia ridges. 
have the same width. 

7. The folds traverse several successive lamine of the phyllade 
for a distance reaching and exceeding 2°0 mm. in length. 

8. A series of such folds traversing several lamine, regarded 
axially, has the appearance of a narrow band of different texture: 
and colour to the rest of the rock: this is due to the reflection 
of light from similarly orientated flakes of mica. 


Sortas—Supplementary Remarks on Oldhamia. 309 


9. In some cases a definite black line marks the surface of the 
undulations of a single lamina. This is produced by some ferru- 
ginous material soluble in hydrochloric acid. It is suggestive of 
the previous existence of an organism, the decay of which might 
have led to a deposition of some compound of iron. Further obser- 
vation of cleaved specimens shows, however, that the ferrugimous 
layer is not restricted to the Oldhamia markings, but occurs evenly 
over the surface of the lamine. 

10. More frequently the cleavage lamin are coated with 
chlorite, which appears in some cases of greater thickness within 
the grooves which represent in imtaglio the ridges of Oldhamia. 

11. In some specimens, straight or undulating, black lines 
run along the axis of a series of folds: these are produced partly 
by a change in direction of black rods, which in other cases run 
parallel to the cleavage lamine, and partly by the in-filling of 
minute cracks formed along the axis of the folds. 

12. In such cases the folds are usually sharper and closer 
together. Seven successive folds were counted in a distance of 
0-8 mm. in one instance. The sericite scales are sharply bent in 
parallelism with the axis. In a hand specimen these sharp, sheared, 
or faulted folds produce an appearance of false bedding on a small 
scale. 

13. They appear to represent a further stage in the folding of 
the rock, which commences with the broader wrinkles of the usual 
kind. 

14. These appearances are remarkably similar to those of 
< TESS GEG ES described by Heim in his “ eae 
dung.” 

15. They also suggest a resemblance to the modified feartbe: 
foliation and cleavage foliation described by Prof. Bonney in his 
last Presidential Address to the Geological Society of London 
(figs. 8 & 4, p. 70), but differ in the fact that the sericite scales 
are conformable with the foldings in the Oldhamia phyllades, but 
not in the quartz gneiss of Muchalls, where they lie at right angles 
to the chord of the folds. 

16. While these observations tend to show that Oldhamia is but 
the incipient stage of “ausweichungsclivage,” they throw no light 
on the remarkable radiate form of the markings. 


(a3 60,4 


XXKVI—ON THE PHYSICAL PROPERTIES OF MANGA~ 
NESE STEEL. By W. F. BARRETT, Professor of 


Experimental Physics in the Royal College of Science 
for Ireland. 


‘ [Read, December 15, 1886.] 


Ar the British Association meeting in Aberdeen, in 1885, Mr. 
J. T. Bottomley read a brief note on ‘A specimen of almost un- 
magnetisable steel.”’ As the magnetisation of iron was a subject 
on which I had worked for some time, Mr. Bottomley was good 
enough to hand over to me this remarkable specimen of steel for 
further investigation, at the same time giving me the name and 
address of Messrs. Hadfield & Co., Steel Founders, of Sheffield, the 
patentees and manufacturers of this steel. 

Upon writing to Messrs. Hadfield, they furnished me with the 
result of a chemical analysis of their patent steel, which is as 
follows :— 

Fe. Mn. C. Si. IP, 8. 
86°68 12°25 0°80 0°15 0-10 0:02 per cent. 


Other varieties of this steel are manufactured, but this is the 
most generally serviceable. Specimens of this steel were first ex- 
hibited at the Institute of Mechanical Engineers in London in the 
early part of 1884, and a Paper describing this material appeared 
in the Engineer for February 8, 1884. From this Paper I make 
the following quotation :— 


““Tt is sufficiently well known that manganese has been employed for 
many years in the manufacture of steel in various proportions, but any- 
thing exceeding 1 per cent., it has been generally believed, would render 
the metal under treatment worthless, and any further addition thereof in 
excess of this proportion has been considered impracticable. In fact, 
Dr. Siemens had stated publicly, on many occasions, that the use of 
manganese was simply a cloak to cover the impurities in steel making, 
that it covered a multitude of sins: and this was the general opinion of 
the steel trade. Méssrs. Hadfield, of Sheffield, however, engaged in a 
long series of experiments and tests, with the object of discovering its 


Barrett—On the Physical Properties of Manganese Steel. 361 


truth, and after a considerable expenditure of time and capital, dis- 
covered that by adding the ordinary ferro-manganese of commerce to iron 
-or steel in such proportions as to produce in the steel or decarbonized iron 
under treatment a percentage of manganese varying from 7 to 20 per 
cent., that the most beneficial results could be obtained. Such per- 
centage is regulated according to the purpose for which the steel is 
required. For instance, to produce a steel suitable for armour-plates 
and other purposes, as we mentioned last week, they add about 10 per 
cent. of rich ferro-manganese, containing, say, 80 per cent. of manga- 
nese, thus obtaining a steel containing about 10 per cent. of manganese. 
For railway purposes they add about 11 per cent.; for steel toys and 
tools, about 12 per cent. They pour this ferro-manganese into the 
molten steel under treatment, thoroughly incorporating it therewith, and 
then run it into ingot or other suitable moulds, and allow it to cool, after 
which it is ready for use, as it requires neither tempering, rolling, 
forging, nor hardening. This treatment of steel in suitable proportions, 
according to requirements, appears to be novel, and renders the steel so 
manufactured harder, stronger, denser, and tougher than most steel now 
manufactured, even when forged and rolled. This steel may, however, 
be forged and rolled in the ordinary manner. Jor casting it has the 
advantage that it possesses greater freedom from honeycombs and similar 
defects ; but the most peculiar property is its great toughness, combined 
with extreme hardness. It is through this that the hitherto indispen- 
sable processes of rolling, forging, hammering, hardening, and tempering 
may be dispensed with, thus effecting for many articles an enormous 
economy in time, labour, and expense. In casting its fluidity enables 
fine steel castings to be made without misrunning, and approaching in 
smoothness iron castings. 

‘¢ Amongst the samples of the steel placed on the table at the meeting 
of the Mechanical Engineers was a sample test bar containing 12 per 
cent. manganese, bent double when cold, though hard enough for turning 
iron; a sample from same ingot shows a tensile strength of 42 tons per 
square inch, with 20°85 per cent. elongation; several hammered pieces ; 
a manganese adze, containing 20 per cent. manganese, just as it left the 
mould; an axe, containing 12 per cent. manganese, just as cast in the 
rough, had chopped through #in. square iron. This, like the others, had 
not been hardened or tempered, only the edge ground.” 


In a Paper read before the American Institute of Mining 
Engineers in May, 1884, some tests of this steel were given, show- 
ing the extraordinary tenacity and hardness of the material. 
‘When hammered or drawn into rods it loses some of its toughness, 


362 Scientific Proceedings, Royal Dublin Society. 


and becomes exceedingly hard. If now the steel be heated {to a 
yellow or nearly welding heat, and then suddenly quenched in 
cold water, instead of becoming harder it loses some of its hard- 
ness, and becomes exceedingly tough, so that the effect produced 
upon manganese steel is Just the opposite to that produced upon 
ordinary steel, which is of course rendered hard and brittle by 
sudden cooling. . 

It was important for the purpose of my investigation to obtain 
a specimen of manganese steel drawn into wire, and Messrs. Had- 
field endeavoured to draw some for me. In this they did not at 
first sueceed; so I begged Messrs. Rylands of Warrington, whose: 
extensive wire-drawing works are well known, to make the attempt. 
They were good enough to oblige me, and, after several ineffectual 
trials, wrote: —“ We gave the steel into the hands of our most expe- 
rienced wire-drawer, a man who is accustomed to draw crucible 
steel wire; but he says that although he gave it every facility, 
putting only half a size on to it, the steel will not draw at all.” 
After much time had been lost in these attempts, Messrs. Hadfield, 
at my request, once more undertook the task themselves; and I am. 
glad to say they have now been completely successful. The 
specimens here exhibited for the first time are long lengths of 
manganese steel wire, No. 138 8. W.G., and also No. 19 S. W. G.,. 
oi two kinds, hard and soft. I requested Messrs. Hadfield to let 
me know the method of wire-drawing they found successful, and 
the following is their account of the process adopted in drawing 
manganese steel into wire :— 


“When first trying to reduce this material from the rolled rods into- 
wire, it was attempted to draw it straight away from the rods; but, 
_ owing to its hardness, very little progress could be made, as the wire kept 
breaking in short lengths. Several methods were tried, such as softening 
it by annealing, as in ordinary wire; but this seemed to make very little 
difference. 

“‘As exceedingly good bending tests had been obtained with bars of 
the same steel when heated to a yellow heat, and plunged into cold 
water, it was thought worth while attempting a similar experiment with 
the rolled rods before trying to draw it down into wire. The rods were 
coiled up, heated to a yellow heat over a smith’s fire, and then plunged 
into cold water. It was then easily drawn into wire, starting with 
No. 7 gauge, when it was drawn to No. 9 with safety. This drawing 


Barrett—On the Physical Properties of Manganese Steel. 363. 


again took out the requisite ductility, and it was therefore necessary to- 
again heat the wire, and plunge it in the same manner as before. By 
doing this each time the wire was reduced two numbers of the gauge; 
- there was no difficulty whatever in drawing it to any desired fineness, 
the only point necessary being that the wire must be heated sufficiently 
hot before plunging into cold water, or the wire would be still too hard. 
The colder the water the better the result.’’ 


The composition of the manganese steel from which the wire: 
was drawn is slightly different from the specimen I obtained from 
Mr. Bottomley. ‘The analysis of the wire is as follows :— 


Tron. Manganese. Carbon. Silicon. Phos. Sulphur. 


84°96 13°75 0°85 0°25 0-10 0°09 per cent. 


I have now to lay before the Society the results of some of my 
experiments with this material :— 

Density.—The density of the manganese steel wire, I find, is 
7°81, that of ordinary steel being 7-717. 

Hardness.—In its ordinary condition manganese steel is very © 
hard. It easily scratches steel that is not hard-tempered. 

Modulus of Elasticity.—The modulus of elasticity (Young’s 
Modulus) was determined by direct stretching. Experiments were 
made with the ordinary hard manganese steel wire and with the 
same wire annealed by sudden cooling. A length of four metres 
was suspended from a well-constructed clamp of a new form, 
devised and made for me by Messrs. Booth, Brothers, of Dublin, 
and the readings were taken by an excellent cathetometer. The 
flexure of the support under the maximum stress was carefully 
tested and found to be inappreciable. An initial weight of 2000: 
grammes was kept on the wire, and additions were made of 10,000 up. 
to 40,000 grammes; with the maximum weight there was no set, the- 
index accurately returning to zero when the weights were removed. 
Three elongations were made in each of five sets of observations, 
the mean of the fifteen trials giving a modulus of 16,800 kilogrammes 
per square millimetre. Another set of observations were made with 
an initial stress of 5000 grammes; adding to this 38 kilogrammes,. 
on and off, the mean of three sets of observations thus made gave 
a rather higher number, namely, 17,130 kilogrammes per square 
millimetre. 

Mr. M‘Cowan, B.Sc., the Demonstrator in Physics at the- 


“364 Scientific Proceedings, Royal Dublin Society. 


College of Science, also took a set of careful observations; the 
number he independently obtained was somewhat lower, namely, 
16,470 kilogrammes per square millimetre. 

The mean of these three series of experiments is the same 
number as the mean of the first fifteen experiments, viz.:— 


16,800 kilogrammes per square millimetre, 


or 1680 x 10° grammes per square centimetre, which may be taken 
as the modulus of hard manganese steel wire. The diameter of the 
wire used was 0:98 millimetres, and the length under observation 
3°455 metres. 

The soft manganese wire was now tried. Six sets of experi- 
ments were made with three or four elongations in each, the mean 
of twenty elongations giving a modulus of 


16,710 kilogrammes per square millimetre, 


slightly below that of the hard wire. 

These numbers are lower than I expected. Iron has a modulus 
of 18,610 kilogrammes per square millimetre. Steel wire varies 
from 18,810 up to pianoforte wire, which is 20,490 kilogrammes 
per square millimetre. 

But this comparatively high rate of extensibility of manganese 
steel is for many purposes a considerable advantage, as it enables 
the material to give under a sudden stress without fracture. 

Breaking stress.—Hxperiments in the breaking stress of the 
wire were now made. The dynamometer I used was tested 
and found correct. A comparative experiment was made with 
pianoforte steel wire, 0:027 inch diameter. This broke at a stress 
of 150 lbs., corresponding to a breaking stress of 117 tons per square 
inch. Ordinary steel wire has a breaking stress of 54 to 63 tons 
per square inch. The tenacity of the best pianoforte steel wire is 
the highest known, and amounts to 150 tons per square inch. 

The soft manganese steel wire, No. 19 S.W.G., or 0°96 milli- 
metres in diameter (that is an area of 0:00125 square inch), broke 
at a stress of 124 lbs., with 18 per cent. elongation : the elongation, 
in fact, was remarkable, being 4 centimetres in 22 centimetres. 
This breaking stress is equivalent to 48-8 tons per square inch. 

The hard wire of the same size had a far higher tenacity and 
far less elongation. The first experiment gave a breaking stress 


Barrett—On the Physical Properties of Manganese Steel. 365 


of 280 lbs., or one-eighth of a ton, which corresponds to the 
enormous breaking stress of 110°2 tons per square inch. A. second 
experiment gave a breaking stress of 278 lbs., which corresponds to 
-109-4 tons per square inch, with an elongation of but little over 
1 per cent.; the ordinary steel wire I tried elongated double this 
amount. Hxperiments on the breaking strain of bars of this steel 
have also been made by Mr. Barnaby, the Admiralty inspector in 
Sheffield, who found that the specimen of manganese steel he tried 
bore a strain of 67 tons per square inch, with the extraordinary 
amount of 44 per cent. elongation before breaking. 

High as is this figure, the number I obtained for the wire was 
far higher, and in fact was so remarkably high that I was anxious 
for an independent determination with another dynamometer. 
Mr. H. A. Ivatt, the Locomotive Engineer of the Great Southern 
and Western Railway Works at Inchicore, kindly undertook this 
for me, as in their works a new and very accurate dynamometer 
has recently been erected. Mr. Ivatt found my figure was per- 
fectly correct, and sends me the following statement :— 


G. S. & W. R.—Locomortve Department, Incuicor—E Works, Dustin. 


z Tensile Stress. 

| Description of prandord) Area, |——___ Appearance of 
aI Date. ) SNiateraiec WES) Sle Tons Fracture 

3, oven: Gauge. | inches. | Total ae ; 
g Ibs sg. in. 


1 | Dec. 13, | Manganese steel wire, No. 19 | -(00125] 291 | 103-8) Hard and brittle. 
from Prof. Barrett, 
29 9 2) be) 3) 310 110-7 ”? 99 


99 op) 2? 3? 9 302 107°9 bb) 9 


Owing to the extremely brittle nature of the metal, the elongation could not be 
detected. 
(Signed), H. A. Ivarr, Locomotive Engineer. 
Tested by W. C. Irwin. 


Mr. Ivatt also tried a specimen of thicker wire, No. 18 gauge; 
but I had previously spoilt this specimen by testing the effect of 
heating it to whiteness and quenching in cold water, which 
rendered the wire soft. This specimen in its soft state, Mr. Ivatt 
found, had a breaking stress of 47-4 tons per square inch, nearly 


366 Scientific Proceedings, Royal Dublin Society. 


the same as I found for the fine wire in the soft state. Mr. 
Ivatt tried to harden it, and writes :—‘‘ Heating the No. 13 wire 
to redness, and allowing it to cool very slowly, is, I find, the only 
way to harden it.’’ This rendered the wire hard and brittle, and 
apparently lessened its tenacity, for the same wire now broke at a 
stress of 38°3 tons per square inch. 

It will be interesting to compare the tenacity of the manganese 
steel wire, in grammes per square centimetre, with that of iron and 
steel. According to Sir W. Thomson (Art. “ Elasticity” Encye. 
Brit., new edit.), the tenacity or breaking stress of — 


Iron wire is, . p . 625 to 651 x 10* grammes per sq. cm. 

Steel wire, : : . 859 to 991 x 104 a 39 

Best pianoforte steel wire, . 2362 x 10# 5 9 

Common pianoforte sie 1851 x 104 J 3 
wire, é : 

Hard manganese steel wire, 1735 x 10 By yh 


The two last are my own determinations. 

Electric Resistance.—I next determined the electric conductivity 
of the wire. For this I employed No. 19 wire, 0°96 mm. dia., in 
a length of 510 cm. This had a resistance of 5°22 ohms, #.e. 
practically an ohm per metre. The resistance of the hard and soft 
wire were exactly alike. The specific resistance was 0:000077 of 
an ohm, or 77,000 C. G. S. units for a cubic centimetre. This is 
very high: the sp. resistance of ordinary iron is 9827 C. G. S., and 
-of German silver wire 21,170 C. G. S. units per centimetre cube. 
Experiments are in progress to determine how far its resistance is _ 
affected by change of temperature; but, in any case, the remark- 
ably high resistance of manganese steel wire points to a useful 
- application of this material for the construction of resistance coils 
for electric lighting and other purposes. 

I now come to the next and most interesting feature of this 
steel—its magnetic inertness. 

Magnetic Co-efficients—Mr. Bottomley, in his note before the 
British Association, to which I have referred, stated that he had 
submitted the bar of manganese steel to an enormous magnetising 
force (far beyond what would be necessary to saturate ordinary 
steel), and after the magnetisation of the manganese steel he had 
determined its intensity of magnetisation, by the deflection of a 


Barrett—On the Physical Properties of Manganese Steel. 367 


mirror magnetometer. The number so obtained showed a magnetic 
moment p = 2°55 C. G. 8. units. Dividing this by the weight of 
the steel we obtain the magnetisation per gramme, which is 0-013 
- ©.G.S. units. Ordinary steel has a number ranging from 40 to 
60, and even up to 100, C.G.S. units per gramme. 

Hence the ratio of the intensity of magnetisation in manganese 
steel to that in ordinary steel is as 1 to 3000, up to 1 to 7700 in the 
best qualities. 

So that the intensity of magnetisation that can be given to 
manganese steel is, say, 5000 times less than that given to steel of 
average quality; or if steel be 100,000, manganese steel is 20. 

This refers to the degree of permanent magnetism that can be 
imparted. It is important to know the co-efficient of induced 
magnetism of this remarkable body. This co-efficient, designated by 
Kf, is the ratio of the intensity of induced magnetisation to the 

0 
H 
termed the magnetic susceptibility of the substance. 

The experimental determination of this constant, for so feeble 
a magnetic body as manganese steel, proved a more difficult task 
than I anticipated, as it is scarcely comparable with iron, and 
therefore like weighing stones and grains on the same balance. 

I first tried the method of torsion adopted by Faraday in the 
determination of the magnetic foree of magnecrystallic bodies, and 
described by him in the last of his “ Experimental Researches in 
Electricity,” Phil. Trans., 1855. 

A platinum wire, hung from a graduated torsion head, sus- 
pended the specimen under examination in a powerful and uniform 
magnetic field obtained from a large electro-magnet. A graduated 
eircle was placed below the object under trial, the zero coinciding 
with the axial position of the object. On exciting the magnet, 
and then turning the torsion head, the object was twisted out of 
its axial position, and at last reached a position of unstable equili- 
brium, when it suddenly swung round to the axial position again, 
but with reversed ends. The degree of torsion required, minus the 
upsetting angle, was used by Faraday to “ measure the force which 
solicits the body to retain its axial position,” that is to say, it is a 
relative measure of the magnetism induced in the body, or its 
susceptibility. 


magnetising force of the field, or K = —: this is now generally . 


368 Scientific Proceedings, Royal Dublin Society. 


A single example out of many experiments will show the 
working of this method. A piece of manganese steel wire 2°15: 
millimetres diameter and 44 centimetres long, was suspended (by a 
platinum wire attached to a torsion head) in a uniform and con- 
stant magnetic field. On turning the torsion head, the upsetting 
angle was found to be 60°, and the torsion required for this was- 
158°. Hence 158° — 60°, or 98°, is the actual force of torsion em- 
ployed. With a piece of fine iron wire of precisely the same: 
length and 0-2 millimetres diameter, the upsetting angle was 70°, 
and the torsion required 320°. Hence 320° — 70°, or 250°, was 
the force required in this case. The ratio of the forces of the two 
bodies are therefore as 1: 2°50. The ratio of the volumes of the 
two substances will be as the squares of their diameters, or as 
1: 115. Assuming the magnetic moment increases as the volume 
of the bodies, the ratio of the forces multiplied by the ratio of the 
volumes will express the ratio of the susceptibilities of the two 
bodies, which gives 

IL 3 Zoe 


There are, however, some objections to this method of experiment, 
as the upsetting angle is not the same, and hence the magnetic 
distribution at two different angles will not be alike in the two 
cases. 

The following method is free from this objection. The force re- 
quired to turn each of the two substances through a given very small 
angle, when they are suspended in a magnetic field of constant 
strength, is found: this value (less the angle of deviation), multiplied 
by the ratio of the volumes of the two bodies, will give the number 
sought. A mirror was attached to the cradle supporting the body, 
.and by means of a lamp and scale, a very accurate measure of the 
angle through which the substance was turned could be obtained. 
A. constant current of 74 amperes was used to magnetize the 
electro-magnet, a uniform field being obtained between two large 
upright pole pieces. ‘The torsion required to turn the manganese 
steel through 18° was in one experiment 42°°5, and in another 42°3, 
ora mean of 42°4°. The torsion required to turn the fine iron wire 
through the same angle was 94°. This, less the angle of deviation, 
gives a ratio of 1: 3. In a more powerful field the numbers were 
66° and 68°, or a mean of 67° for the manganese, and 155°5 and 


Barretr—On the Physical Properties of Manganese Steel. 369 


156°:5, or a mean of 156° for the iron, a ratio of 1:2°8 The 
volumes of the bodies being as 1 : 115, the former experiment 
gives a ratio of the susceptibilities as 1: 345 and the latter as 
1: 322. Hence we may say that the manganese steel has about 330 
times less magnetic susceptibility than soft iron; or, if iron be 
100,000, manganese steel will be about 300—a very different 
number, it will be observed, from that obtained by Mr. Bottomley, 
for the intensity of permanent magnetisation of the two bodies. 

A few experiments were now made to determine whether this 
method showed that the magnetic moment was directly propor- 
tional to the volume of the material. Half-a-dozen pieces of fine 
manganese steel wire were cut, of equal lengths, and the upsetting 
force and corresponding angle determined in each case. The angle 
being 60°, the upsetting forces, less this angle, were as follows :— 


Upsetting Force 

Force. per piece. 
With 1 piece, . ; : : 132 132 
3 2 plecess. : : 236 118 
Kotor cyayen ay ie ‘ : 400 133 
Fai Si ae Aaa : : 6 538 134 
Sey OU veAP Lae : 6 664 133 
6 798 132 


3 


Dividing the upsetting force by the number of pieces in each 
case, we obtain the force per piece, as shown in the last column. 
With the exception of the second experiment—which is evidently 
erroneous—it will be seen that the forces are directly proportional 
to the number of pieces, and hence to the volume of the body. © 

Since I began this investigation, Dr. J. Hopkinson has sent 
me his paper on the “ Magnetisation of Iron,” read before the 
Royal Society of London, in April, 1885. Until I received this 
paper I was unaware that Dr. Hopkinson had been experimenting on 
the magnetic properties of manganese steel. The method adopted 
by Dr. Hopkinson to determine the magnetic susceptibility was 
wholly different from that which I employed, and consisted in 
measuring the induced current generated by the sudden removal 
of a small coil of wire that encircled the iron or steel bar under 
experiment, and which bar had previously been submitted to a 


powerful magnetising current. he maximum magnetisation of 
SCIEN. PROC. R.D.S.—VOL. V. PT. Y. 2C 


370 Scientific Proceedings, Royal Dublin Society. 


wrought iron and of manganese steel (with 12°36 per cent. of 
manganese) deduced from Dr. Hopkinson’s figures are as 1441 to 
5:6, or 258 to 1. 

These numbers are fairly in accordance with those I have 
obtained, viz. 330 to 1, for steel containing 13°75 per cent. of 
manganese. Considering the wide range of the figures in the table 
given by Dr. Hopkinson, I should imagine that his ratio is some- 
what less reliable than the one I have given. 

Other Magnetic Properties.—It was interesting to ascertain 
whether the presence of this percentage of manganese in steel 
deprived it of other well-known magnetic properties. As might 
be expected, it showed no elongation under magnetisation. It did 
not exhibit the magnetic tick or sound heard when iron, steel, 
nickel, or cobalt is magnetized and demagnetized. A more in- 
teresting question was whether it would exhibit the anomalous 
expansion and after-glow which take place in iron or steel wire 
when they cool to a certain critical temperature, after being 
heated to whiteness. JI have shown that these phenomena are 
coincident with that temperature when the magnetic state of 
these metals, destroyed by a high temperature, is resumed on cool- 
ing. Careful experiments with the manganese steel wire, heated 
to a bright whiteness, established the fact that no trace of this 
anomalous deportment on cooling occurred with this substance. 
Here then we have a singular and an important link between 
the magnetic state of a body and its sudden and momentary ex- 
pansion and reheating, when at the critical temperature. Like 
manganese steel, the non-magnetic metals—platinum, copper, 
German silver, silver and gold wire—do not exhibit this phe- 
nomenon.’ 

I have good hope that the experiments here recorded will be- 
come a starting-point for further investigation. When we remember 
that 13 per cent. of a non-magnetic metal, mechanically mixed with 
iron or steel, produces but a slight change in the magnetic state of 
the latter, and then consider the profound magnetic change brought 
about by 13 per cent. of manganese (itself a feebly magnetic metal) 


1 Nickel, I find, does not exhibit it, contrary to my expectation ; but the magnetic 
state of nickel is lost at a temperature of 330° to 340° C., which is considerably below 
red heat. Cobalt wire I have not yet been able to obtain. 


Barrett—On the Physical Properties of Manganese Steel. 371 


when alloyed with steel, we are led into speculation as to the nature 
of magnetism, and why chemical union should destroy the mag- 
netic state. Manganese steel has about the same magnetic suscep- 
tibility as ferric oxide; German silver, in like manner, which is an 
alloy of brass with the magnetic metal nickel, is itself magnetically 
inert. Why is this? Do the molecules of manganese insulate the 
imaginary Amperian currents in the iron, and so prevent the mole- 
cular movement which invariably accompanies the act of magneti- 
sation? But if so, how? ‘The electric resistance of manganese 
steel, as a whole, is scarcely 8 times less than iron, but the magnetic 
power is upwards of 300 times less. 

These experiments have also a practical as well as a theoretic 
interest. From its high tenacity and negative magnetic properties, 
manganese steel is eminently adapted for the construction of those 
parts of machines where the magnetic properties of iron or steel 
are a serious disadvantage—such, for example, as the bed-plates of 
dynamos. 

Moreover, as everyone knows that the deviation of the com- 
pass on iron ships is a grave danger in navigation, more especially 
from the fluctuating character of the sub-permanent magnetism 
due to the hard iron and steel, the use of manganese steel for the 
construction of iron vessels and of ironclads in the navy, and for the 
anchors and chain cables of all vessels, suggests a simple mode of 
returning to the magnetic safety of our wooden vessels without 
sacrificing the advantages of iron.’ 


1 When the foregoing Paper was read, Mr. Fletcher Moore, of Kilbride Manor, 
called attention to the fact that a manganese iron ore mine existed at Kilbride, Co. 
Wicklow, and stated that from this ore iron had been smelted of great tenacity and 
high quality. 


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ee] 


XXXVII.—IRISH MARBLES AND LIMESTONKES. 
KINAHAN, M.R.1.A., Eve. 


[Read, November 17, 1886.] 


CONTENTS. 


Intropuction: Marbles, Limestones, Cretaceous, Lias, Trias, 
Permian, Carboniferous, Silurian, Ordovician, Cambrian, 
Lime, Hydraulic limestone, Plaster of Paris, . 


Marstes: Carboniferous. Red and variegated—-Armagh, Clare, 
Cork, Dublin, Kerry, Kildare, Limerick, Longford, Tip- 
perary. Black—Carlow, Donegal, Fermanagh, Galway, 
Kerry, Kilkenny, Limerick, Mayo, Monaghan, Sligo, Tip- 
perary, Waterford. Grey—Armagh, Carlow, Cork, Galway, 
Kerry, Kilkenny, King’s County, Limerick, Longford, 
Tipperary, Waterford, Westmeath. Various colowred— 
Clare, Donegal, Fermanagh, King’s County, Tipperary, . 


Meramorpuic Rocks: Metamorphic limestones. White and 
red—Donegal, Galway, Louth. Sienna-colowred—Donegal, 
Galway. Black—Donegal, Londonderry, 


Mernytotic Limesrones anp Dotomyres: Green and varie- 
gated—Galway, 


Meruytoric Exoric Rocks: Dark-green and variegated Ophytes— 
Galway, Mayo, Sligo, Tyrone, Waterford,-Wexford and 
Wicklow. Lklogyte—Galway, Mayo, Sligo. Steatyte, or 
Soapstone—Donegal, Galway, Mayo, Wicklow. Pyro- 
phyllyte, or Camstone—Cork, Donegal, 


Limzsrone Quarrizs: Antrim, Armagh, Carlow, Cavan, Clare, 
Cork, Donegal, Down, Dublin, Fermanagh, Galway, 
Kerry, Kildare, Kilkenny, King’s County, Leitrim, 
Limerick, Londonderry, Longford, Louth, Mayo, Meath, 
Monaghan, Queen’s County, Roscommon, Sligo, Tipperary, 
Tyrone, Waterford, Westmeath, Wexford, Wicklow, 


By G. H. 


PAGES- 


373-381 


381-3895: 


395-399" 


400-404 


404-412" 


412-444 


Krnanan—On Irish Marbles and Limestones. 340 


INTRODUCTION. 


Ir appears expedient to give, as an introduction to the subject of 
the following pages, an epitome of the geological and lithological 
relations of these rocks to one another, and subsequently classified 
lists and sub-lists—those classed as marbles being separated from 
those more suited for cut-stone purposes: necessarily, however, 
most of the marbles are also applicable for more general uses. 

The lists of the marbles will be as complete as possible, and in 
them will be included all places where stones have been worked as 
marble, whether successfully or otherwise. ‘To these will be added 
other places in which stones are found that may possibly be here- 
after utilized. 

Marbles proper are limestones or metamorphosed limestones of 
a nature capable of taking and retaining a good polish. The 
metamorphosed limestones belong to two divisions—those that 
have undergone simple metamorphism, that is, have only been 
altered by the action that affected the associated rocks; and those 
that underwent a second or after change, due to chemical action 
from without (methylosis). These secondarily changed limestones, 
including dolomytes (ophiolytes, ophicalcytes, dolomytes, &c.), are 
generally called Serpentine ; but under this general name are also 
included chemically-allied rocks (ophytes, eklogytes, steatytes, pyro- 
phyllytes, &c.), rocks that originally were in general of volcanic 
origin. It therefore is expedient to include these also under the 
title of marble, and class them all together, not only on account of 
their chemical relations, but because all are generally recognised as 
marbles; and, if separated, would lead to confusion. As they 
will be hereafter given in separate sub-lists, and their proper 
relations to one another be pointed out, there will be no incorrect 
scientific classification. | 

The marbles will be classified as much as possible according to 
colour, under the county names, placed alphabetically; while, at 
the same time, their geological and lithological positions will be 
kept separate, and each will be described so as to give a general 
knowledge of the rocks, and the probability of their being of 
economical value. 


374 Scientific Proceedings, Royal Dublin Society. 


The list of the limestone quarries will not be so full, as it 
would be unnecessary and undesirable to mention all quarries ; 
the nature of the proposed list being to point out as many places 
as possible where good stones, suited for cut-stone purposes, can be: 
obtained, or stones that, from some specialty, are eminently suited 
to be used in the construction of piers, harbours, or such-like: 
massive works. These lists will be complete, as far as possible: 
but some isolated quarries, locally, though not generally, known, 
may be omitted. At the end of each county list is given the 
general nature of the lime, and other purposes are mentioned to. 
which the stone has been applied. In the counties where lime- 
stone is scarce, all localities in which it is found are given, whether 
they are suitable for cut-stone purposes or not. 

The geological grouping adopted is the same as that given in 
the Table of Geological Strata in the Paper “On Irish Metal 
Mining”’ (ante p. 204). 

Some of the recent limestones accumulating at the present 
time might be utilised in the manufacture of articles of vertu. 
They scarcely, however, come within the scope of this Paper, 
although it would be incomplete without a reference to them. 
Such are the stalactytes and stalagmytes of the caves, and the: 
massive tufas accumulating in the vicinity of some of the cal- 
careous springs. 

Next before these in geological order is the Cretaceous or White: 
Limestone, of a similar age to the English Chalk, but possessing,, 
on account of its induration, a distinct character of its own. ‘This 
stone is principally quarried to burn into lime, as it is not suited 
for fine tool-work, being full of concealed cracks and irregular 
joints. It can, however, be scabbled into stones of small dimen- 
sion, very suitable for rough masonry. In some places it is ground 
up, and manufactured into whiting. 

The limestones belonging to the Lias are of little note, being” 
only nodules and layers of small dimensions, and apparently of 
little value, as all attempts to convert them profitably into a cement. 
have, up to the present, failed. 

In the Trias there are, in a few localities, massed and lenticular- 
beds of gypsum. 

In the Permian beds, the only known calcareous rocks are 
dolomytes. They are so rare, that they have been little utilized, 


Kinanan—On Trish Marbles and Limestones. 370 


except some near Belfast, which were formerly exported to Scot- 
land for the manufacture of sulphate of magnesia. 

In Ireland, the great development of limestone was in the 
Carboniferous Period. These rocks occupy nearly the whole of 
the central plain, with ramifications from it, and in some places 
they exist in tracts that are more or less isolated and of variable 
extent. In these the characters of the rocks differ greatly, some 
being nearly pure limestone, while others are argillaceous or arena- 
ceous, often to such an extent as to almost lack the calcareous 
constituent. 

For convenience of description, the Irish Carboniferous Lime- 
stones may be subdivided as follows :— 

I. The earthy erystalline, or Lower-Bedded Limestone. 'These 
rocks are more or less common at the margins of the tracts of the 
different types of limestone ; they are bedded, and in general have 
shales or clayey partings between the beds, and are often capable 
of being raised in large masses, but rarely are they eminently 
suited for cut-stone purposes. As large blocks, they are valuable 
in the building of piers, foundations, or other massive works. 

IJ. Amorphous or Fenestella Limestone. The latter name has 
been suggested by Wynne, as the mass of the rock in general is 
made up of this Corralline. The rock originally seems to have 
been coral reefs, any bedded portions in it being for the most 
part above or below, or as isolated subordinate parts in the mass. 
This rock, in general, is not suited for cut-stone purposes, although 
some of the included portions, when manufactured, afford beautiful 
marbles. At the present time, except some few beds, none of the 
rocks of this type seem to be in much favour with the marble- 
workers; yet from them our ancestors were able to produce exqui- 
site specimens of art. The work cut from stones of this class in 
the Geraldine banqueting hall atAskeaton, Co. Limerick, and that, 
in the chaste and beautiful pillars of the cloisters in the adjoining 
abbey, cannot be surpassed. 

III. Calp, or earthy compact limestone. These rocks are, in 
general, not good for cut-stone purposes; but they can usually be 
raised in large blocks, for which reason they are valuable for 
massive works. Some beds, however, are very compact, homo- 
geneous, and capable of taking a fine polish, and, under such 
circumstances, have produced first-class marbles. 


376 Scientific Proceedings, Royal Dublin Society. 


IV. Burren type. 'The limestone of this class was so called by 
Foot on account of its being best developed in the barony of 
Burren, Co. Clare. These rocks, when typical, are in shades of 
grey and blue, being crystalline, but compact and free-working ; 
while many beds are suitable for all kinds of cut-stone work. All 
the chief Irish quarries of the present day are situated in the 
limestone of this type, and in ancient times all fine workman- 
ship, with rare exceptions, such as the work at Askeaton, was 
executed in stone of this class. It might naturally be expected 
that the principal black marbles should be found in the Calp: 
this, however, seems not to be the case, as some of the world- 
famed Irish black marbles are from subordinate beds in the lime- 
stone of the ‘“ Burren type.” This, to us, appears to have led to 
a misconception, as some of the tracts classed on the geological 
maps as “Calp” are so called solely from their having in them 
beds of black marble, while, correctly speaking, they should be 
mapped as “ Burren limestone.” 

It is necessary to explain that the above classification is solely 
a lithological one, the rocks being arranged according to their 
general characters, and not to their geological position. The ordi- 
nary geological classification has been found, even by those who 
still use it, to be unstable, as the rock-characters, at first adopted 
as conclusive of age, being now found to vary according to the 
circumstances under which the rocks accumulated; purer lime- 
stones accumulating in deep water, while littoral and shallow water 
depositions had peculiar and special characteristics. The rocks of 
class I. were evidently littoral accumulations; those of class IL; 
the growth of coral reefs or such like; those of class JII., accumu- 
lations in greater or lesser expanses of shallow, still water, into 
which fine silt or mud was drifting; while the nature of the 
accumulations of the rocks of the Burren type is hard to deter- 
mine, as at the present day there do not appear to be any records 
of exactly similar depositions. 

We have adopted as much as possible the recognised names—a | 
plan which may be, in part, unsuitable to pure geology; but, at 
the same time, as the geologists of the present day, in respect to 
Europe in general, and also more or less elsewhere, are colouring 
their maps, rather in accordance with lithology than geology, it 
seems allowable for us to adopt the names that are best known and 


Kinanan—On Irish Marbles and Limestones. Ole 


that will be most intelligible, especially when the correct definitions 
of the names are also given. 

Other Carboniferous limestones are those that occur as te 
basal beds of the Carboniferous rocks, associated with the con- 
glomerates, in the counties of Clare, Galway, and Tipperary. 
These, however, are of minor importance, and appear to have been 
but little utilized. 

There are also limestones that occur at the margin of the 
‘Ordovician (?) or Cambrian (?) metamorphic rocks to the north- 
ward of Castlebar, Co. Mayo, which Symes suggests are of Car- 
boniferous age (Geol. Surv. Mem.). His arguments cannot be 
lightly passed over; the principal ones being that these limestone 
are unconformable to the associated rocks, that they occur in more 
or less dyke-like masses, and that they are devoid of the characters 
-of metamorphic limestone. An examination of the rocks seems to 
prove that they must be much more recent than the adjacent meta- 
morphic rock, and that they are of Silurian or Carboniferous, or 
even of a later age. Symes, after his examination, suggested that 
they were Carboniferous, and due to the filling in of open fissures, 
during that period, with Carbonifereus matter. It is, however, 
possible, as has been suggested by myself, that these fissures were 
filled in by Silurian limestone. ‘To this we shall refer presently. 
All these limestones are more or less used for lime, some of them 
being hydraulic. 

In the Silurian group (which includes the rocks that have been 
called Upper Silurian and Lower Old Red Sandstone) limestones are 
rare, and occur in beds of small dimension. They have been 
recorded in the following places: —At Croaghmartin, in the Dingle 
promontory, Co. Kerry, are some insignificant arenaceous lme- 
stones. In the Co. Galway, at Salrock, Derreennasliggaun, and 
Leenaun, there are small subordinate masses of limestone, those at 
Derreennasliggaun being in part somewhat coloured red. Farther 
eastward, partly in the counties Galway and Mayo, are peculiar 
limestones, associated with the eruptive rocks that occur at the 
base of the Toormakeady conglomerate. ‘These rocks are very 
interesting, as they may possibly be of the same age as the lime- 
stone northward of Castlebar, which, as suggested in the previous 
paragraph, may be either Carboniferous or Silurian. South-east- 
ward of Louisburgh, in S. W. Mayo, there are thin limestones, in 


378 Scientific Proceedings, Royal Dublin Society. 


part schistose (metamorphic). In N. E. Mayo, between Charles- 
town and Ballaghaderreen, in two places, there are beds of 
impure limestone; and in the Co. Tyrone, between Sixmile-cross 
and Pomeroy, there are three or four beds of limestone. These 
Silurian limestones have been utilized for lime, especially those in 
South Mayo and Tyrone. Hydraulic limestones occur near Tour- 
makeady. . 

Limestones in the Ordovicians (Cambro or Lower Silurians) are- 
not very uncommon, having been recorded in the Cos. Wicklow, 
Wexford, Waterford, Galway, Mayo, Sligo, Donegal, London- 
derry, and Tyrone. All are more or less schistose (metamorphic), 
and usually are not suitable for cut-stone purposes; there are, 
however, some stones in the Co. Donegal, that appear to belong to- 
this group, which have produced excellent work. All these 
limestones are more or less utilized for lime, some of them being 
hydraulic. 

Limestones of Cambrian age are found in Galway, and 
probably in Donegal. There are also limestones in the Cos. 
Londonderry, Tyrone, Sligo, and Mayo, in rocks that may be 
metamorphosed Cambrians; but the age of these rocks has not 
been satisfactorily determined. These are all more or less meta- 
morphosed, some also being chemically changed into Serpentine. 
They are not in general good for cut-stone purposes, but beds both 
in Galway and Donegal have been worked, and found to dress 
well; while some have also been worked as marble. The green 
and variegated Serpentines of West Galway have been worked for 
marble, and are well known in the market. The more general 
purpose for which the Cambrian limestones are quarried is the 
manufacture of lime. 

Lime.—As a general rule Irish limestones are suitable for the 
production of lime, some of them being eminently so. The prin- 
cipal exceptions are found in the Calp, some beds in which are so 
arenaceous, or argillaceous, that they are rather sandstones, or 
shales, than limestones. Some of these will not burn at all; others. 
only with great care. 

The richest limes are produced by the White and Fenestella 
limestones, some, indeed, being too rich for sound building pur- 
poses, unless they are properly mixed with clay and sand. The 
limes are almost invariably of a good white colour. 


KinaHuan—On Irish Marbles and Limestones. 31D 


The major portion of the other limestones, as a rule, give 
more or less dark-coloured limes ; while some from the metamor- 
phic limestones, especially those of Ulster, are so dark as to appear 
more like brick-dust than lime; in general, however, they are- 
good strong limes. Most of those from the rocks of Carboniferous 
age give a good return, but the returns from the Metamorphic 
rocks are usually below the average. 

The strength and durability of lime made from some of these 
limestones are shown in ancient, and even modern structures. In 
various places, in the ruins of the ancient castles and other build- 
ings, it can be seen that as the buildings came to be demolished, the 
mortar proved stronger than the stone. This is well exemplified 
in the old castle in the Flats of the Shannon, near Clonmacnoise, 
which was built on an artificial clay mound. When the Shannon 
cut away the clay foundation the castle fell in masses, the weight 
of the latter breaking through the stones, while the mortar re- 
mained unbroken. The Round Tower, Kilmacduagh, Co. Galway, 
leans over considerably out of the perpendicular, and has not 
given way, although some years ago it was struck by lightning, 
and cracked at the top. A modern example of good work was the 
garden wall at Cowper’s Hill, Queen’s Co., built some hundred 
years ago. This had to be removed, but as both the bricks and 
mortar were of such excellent qualities, that the wall could not be 
pulled down without great expense and labour, it was cut into 
junks, and moved to its new site. 

As stated, in some places the limestones are hydraulic. These: 
were used in various waterworks, constructed some years ago, the 
localities for the different stones being then known; a list was 
drawn up some thirty years ago by Griffith, but it was never 
published, and now it seems to be lost.' 

The localities at present known for hydraulic limestones will 
be given in their respective counties; but these will not embrace 
all that really exist, as the published records are scant. 

The natural cements are not of the same value now as they 


were formerly; for, as Wilkinson and General H. Y. D. Scott, R. E. 


1 The late Mr. John Byron informed us it was, he believed, destroyed by Griffith, 
who considered it useless, as ‘‘ natural cements’’ (made from hydraulic limestone) had 
been superseded by artificial cements. 


“380 Scientific Proceedings, Royal Dublin Society. 


(Proc. Inst. Irish C. E., May, 1880), have pointed out, they give 
uncertain results, one portion of a bed, or accumulation, being so 
different from those adjoining. This has in a great measure led 
to the general use of artificial cements, which can be made of a 
uniform quality and strength. Consequently, the Irish hydraulic 
limestones have been for years almost entirely ignored. 

Scott and others have shown that cement can be manufactured 
from any limestone if the proper constituents be added. ‘This, 
however, requires considerable skill in manipulation, which is only 
to be acquired in time by careful observation on the part of the 
workers while making the cement. The great art in making 
cement consists in getting materials that can be easily and cheaply 
associated, so as at the same time to produce a good article. 
Various attempts have been made in Ireland, and although as 
good as that imported, if not better, has been made, yet the results 
pecuniarily have not been very satisfactory. 

There are, however, some clays in Ireland that might possibly 
give good results. Near Ballynamona, west of Cong, Co. Galway, 
there is a clay that was successfully used in the manufacture of 
-eement for the waterworks at Ashford, Cong (Geol. Surv. Mem.). 
Again, the violet-coloured lithomarge found in the “Iron Mea- 
sures,” Co. Antrim, seems to have qualities identical with those 
of the Pozzuolana of the Bay of Naples. It has not, however, 
yet been experimented on. ‘There are the muds of some of the 
estuaries which ought to contain the ingredients necessary for 
cement, if lime were added to them, or, perhaps, in some cases 
even without the latter. These also, however, have not as yet 
been tried, except some in the estuary of the Slaney, Co. Wexford, 
_which are now being employed in the manufacture of a first-class 
cement at Drinagh, south of Wexford. 

Plaster of Paris.—In connexion with the rocks of Triassic age, 
no limestones, except the supposed Permian dolomytes,' have been 
found, but in some places there are accumulations and beds of 
gypsum. At Derrynasrobe and Knocknacran, near Carrickmacross, 
Co. Monaghan, there is a thick accumulation, which has been proved 
for a depth of 60 feet. Plaster of Paris was manufactured in this 


1 The dolomyte, with Permian fossils, at the Annaghone Colliery, Co. Tyrone, 
occurs in intimate connexion with the Trias. 


Kinanan—On Irish Marbles and Limestones. 3sl 


neighbourhood, but the works were accidentally burnt down a few 
years prior to 1870, and since then the manufacture has not 
been resumed. Gypsum has been found associated with salt near 
Carrickfergus; also in the valley of the Lagan, Co. Antrim. 
Dr. Ruttey, in his Natural History of Dublin, mentions it as 
occurring at Multikartan, near Lisburn, and it has also been 
found at Coagh, Co. Tyrone. 

The variety called alabaster, suitable for architectural and orna- 
mental purposes, is not recorded as having been found. 


MARBLES. 


The Irish marbles are not only very varied, but some of them: 
are handsome, and even beautiful. They occur among the Carbo- 
niferous limestone and the Metamorphic rocks, the latter being of 
Ordovician and Cambrian ages. or the most part they are lime- 
stone; but some are more or less chemically changed, and are 
known under the general name of Serpentine. The latter name, 
however, not only includes the altered limestones and dolomytes, 
but also certain altered volcanic rocks. The metamorphosed lime- 
stones and allied rocks will be more specially mentioned here-- 
after. 


CARBONIFEROUS. 


The limestones of Carboniferous age capable of being worked 
as marble occur in various shades of red, black, grey, and other 
colours. The red varieties of limestones are rarely of one uniform 
colour, being usually more or less clouded or variegated. Some of 
these are beautifully and fantastically marked in lines or clouded 
tints of grey, white, purple, green, and yellow, and deserve to be 
much more generally known than they are at present. Some of 
the black limestones are world-famed, and cannot be surpassed for 
blackness, or for the beauty of the stone; while others are more or 
less mottled or spotted with white, generally owing to the presence 
of fossils. The grey tints graduate from dark to almost white, 
being often more or less clouded with darker shades, and also- 
with purple, changing them into dove-colour. 


082 Scientific Proceedings, Royal Dublin Society. 


RED and VARIEGATED MARBLES. 


[Rep and VARIEGATED stones are recorded, and have been worked more or less in 
the Cos. of Armagh, Clare, Cork, Dublin, Kerry, Kildare, Limerick, Longford, and 
Tipperary, those that have been principally worked occurring ,in the Cos. Armagh, 
Cork, and Limerick. ] 


ARMAGH. 


The marble quarry at Armagh was at one time very extensively 
worked both for building stones and marble. In the principal bed 
the colour was a pinkish-grey, which, when polished, was of a 
warm yellow colour. From this bed large blocks suitable for 
columns were procured ; and associated with it were reddish beds, 
alternating with whitish. These were quarried for the purpose of 
being wrought into chimney-pieces and other ornamental work. 
The rocks formerly raised seem to have been better than those at 
present obtained ; or else tastes may have changed, as now the 
rocks are considered light in colour and unsatisfactory, and their 
place has been taken by the Cork and Belgian “ reds.” 

At the present time (Geol. Sur. Mem.) there are four separate 
series of marble—(1) Uppermost are ten feet in thickness of vari- 
egated bluish-red stone, in beds from one to three feet thick; 
(2) A little below these is the white marble, a pale, crystalline rock, 
forming a bed three feet thick; (3) Two feet under the latter is 
the shell marble, a fossiliferous bed, of about one foot in thickness, 
of a purplish-brown colour, variegated with green and yellow, while 
nine inches lower is—(4) the thrush marble, consisting of ten feet in 
thickness of a mottled-purplish rock, marked somewhat like the 
breast of a thrush. 


CLARE. 


To the south of the Co. Clare, a little east of the Fergus 
between Newmarket and the Shannon, there are beds in the 
Fenestella limestone which have been worked as marble, and were 
used for ornamental purposes in Adare Manor, Co. Limerick, and 
elsewhere. The stones are red, red clouded with grey, and 
grey clouded with red. They do not rise in well-shaped blocks, 
but good-sized stones may be raised which can be scabbled into 
blocks of fair dimensions. 


Kinauan—On Irish Marbles and Limestones. 383 


Cork. 


The best Irish “reds” in the market at the present time are 
procured in this county. They have been worked at Boreen- 
managh, Churchtown, and Little Island, near Cork; Johnstown 
near Fermoy, Midleton, and near Buttevant. These marbles are 
well known, and have been extensively used. They vary in colour, 
from a red, like jasper, to streaked and variegated. All except 
those at Boreenmanagh, Johnstown, and Midleton, are of one 
type, known in the market as “Cork reds.” At Midleton the 
stone varies from a warm dove-colour to a rich variegated marble, 
while those at Boreenmanagh and Johnstown are semi-transparent, 
mottled, or clouded with white and grey. 

These stones have been used in the following instances, among 
others:—The Little Island “red,” in the Liverpool Exchange, 
the Manchester Exchange; Museum, Oxford; St. John’s College 
Cambridge, &e. The Fermoy “red,” in the Gxihetron, Queens- 
town; Roman Catholic Church, Thomas-street, Dublin, &c. 

The Midleton stone has only lately been known, but it has 
rapidly taken a place. It is more properly a clouded grey than a 
true red. It has been used, among other places, in the Manchester 
Exchange; St. Mary’s Church, Bradford, &ce. 

Cork “‘reds”’ have also been used in the Town Hall, Rochdale ; 
Miss Bottomley’s, Bradford; St. Mary’s, Abbots, Kensington ; 
St. Pancras Hotel and Station, &e. 


DvuBLIN. 


In this county, at Johnstown, there is a red stone which was 
tried, but it seems not to have been much approved of, and has 
now ceased to be spoken of. 


KERRY. 


Near Killarney there is a striped red-and-white stone which has 
been worked a little, but unsatisfactorily. In other places in the 
county there are reddish and pinkish stones on which trials have 
been made, but as yet no good profitable stone has been found. 


oot Scientifie Proceedings, Royal Dublin Society. 


KILDARE. 


At Celbridge is a stone recorded by Sir R. Kane, but it does. 
not appear to have been worked to any extent, and its existence is 
generally now ignored. 


LiMERICK. 


Red marbles (“reds’’) have been more worked in this county 
than in any other except the Co. Cork. This may possibly be due 
to the action of the late Earl of Dunraven, who, during the erection 
of Adare Manor, seems to have searched the counties Limerick and 
Clare for “‘reds,”’ specimens of which can be seen in different por- 
tions of the edifice, some having been used in outside work, while 
most of them are represented in the chimney-pieces and in orna- 
mental slabs used for decoration. 

In general the “ Limerick reds” are clear-coloured, varying 
from shady or coloured red to variegated, with grey, green, yellow 
and other tinges; this, however, is not the case in the Pallaskenry 
rock, which is of the type known as the “Cork reds.” This rock 
was extensively used by Lord Clarina when building his new 
mansion, and by Lord Dunraven at Adare Manor. 

At Clorhane, two and a-half miles north of Adare, half a mile 
west of Stone Hall, immediately west and north-west of the old 
church, also half a mile to the west, and half a mile to the south- 
west of the new church, are quarries which were open and worked 
during the erection of Adare Manor. In these places, except at 
Clorhane, the works were of small extent, only a few blocks being 
removed to be worked into slabs for chimney-pieces. At Clorhane, 
however, all the “red” was taken away, but some years after- 
wards the grey stone below began to assume the red colour. 

Other places in this county, in which red rocks are recorded, 
are, a little east of the ruins of the ancient church, to the N. H. of 
Clorhane Bridge, and in the railway cutting south of Askeaton, a 
pinkish-greyish stone, in places yellowish, was used for the beauti- 
ful pillars of the cloisters of Askeaton Abbey, built by the Karls of 
Desmond (Geraldines) in the fourteenth or fifteenth century. ‘The 
exact places where this stone was procured is now unknown, but it 
evidently came from some place in the neighbourhood. 


Kinanan—On Irish Marbles and Limestones. 385 


LonGForD. 


Near Ballymahon, brown red and mottled-grey stones were 
- formerly worked (Kane). 


TIPPERARY. 


Near Dunkerrin are recorded stones of red to purplish colour, 
veined with yellow (Hane); but no extensive works seem to have 
been carried on. Different marbles appear to have been sought 
after in this county during the time the marble works at Killaloe 
were in full work. 


BLACK MARBLES. 


[Black Marbles have been worked, or have been found, in the Cos. Carlow, 
Donegal (?), Fermanagh, Galway, Kerry, Kilkenny, Limerick, Mayo, Monaghan, 
Sligo, Tipperary, and Waterford. ] 


The black marbles of Kilkenny are historic. Although we 
have in very ancient structures, such as those of Askeaton, Oo. 
Limerick, and Clonmacnoise, King’s County, examples of very 
ancient marble, yet the first written record of Irish marbles seems 
to be that of Gerrard Boate, written in 1652. 

The Irish black marbles were at one time in great request, 
quarries in various counties being worked in a great measure for 
exportation to England and elsewhere. The black varieties were 
principally in demand, but also the black speckled or marked with 
white. The pure black marbles were chiefly required for monu- 
mental purposes, but not always, as a considerable quantity of the 
Angliham stone, Co. Galway, was exported to London forthe Duke 
of Hamilton’s staircase, in his mansion in Scotland. Although 
in later years the best “ blacks” were most in requisition, yet the 
black mottled or spotted with white, like the famous Kilkenny 
marble, which got the Irish marbles a name, were much sought 
after ; and also inferior “blacks,” the latter being required for 
local trade in tombstones and such like. Now the trade in “ blacks” 
is very low, none but the best, which have an extensive sale, being 
much looked for. The black-and-white are not now in much 
requisition ; while the fashion in tombstones of late years has so 
changed, that inferior “ blacks”’ have now no place in the general 


market. ‘For these reasons, combined with the gradual depression 
SCIEN. PROC. R.D.S.—VOL. V. PT. V. 2D 


386 Scientific Proceedings, Royal Dublin Soctety. 


in trade, only a few out of the great number of quarries at one 
time in work are now profitable. The best ‘“ blacks”’ only will be 
received in the London market : formerly there was a competition 
for them between it and the American market. 


CARLOW. 


In the town of Carlow two quarries were formerly worked, one 
at Montgomery-street, and the other in the townland of Crossnear, 
the latter being in the suburb called Graigue, west of the river 
Barrow, in the Queen’s County. In the Montgomery-street quarry 
there were four beds, 7 inches, 2 feet, 3 feet, and 18 inches thick, 
the thin beds giving the best marble. In the Graigue quarry there 
was 5 feet in thickness of a stone, that was worked for tombstones, 
and sent to the Dublin and Waterford markets ; and under it were 
nearly 2 feet of superior black stone. In the Carlow quarry, the 
limestone over the 18-inch bed could also be used for work of a 
similar nature. Carlow was once famous for its tombstones, and 
at the present time the trade is still carried on, very creditable 
work being sent out from the stonecutters’ yards; but it has sadly 
fallen off from what it once was; this being, in a great measure, 
due to the fact that sandstone monuments are now most in 
requisition. 

Royal Oaks.—A. little more than a mile west of Bagnalstown 
there is a large quarry, in which marble was procured; and a 
second further north, nearly a mile south-west of Killinane House. 
In both these places stones for black marble were, in time past, 
extensively worked, some being fit for the London trade. 

Ballynabrannagh, northward of Milford.—A. good black marble 
was formerly procured in this quarry. 

Clogrenan.—There is here a quarry in limestone, immediately 
~ under the coal-measures. One bed is a good black, partly spotted 
with white. It has not been very extensively used. The columns 
in the hall at Clogrenan House were cut out of this stone. 


DONEGAL. 


As mentioned by Kane, in his Industrial Resources of Ireland, 
there is in Kintale, to the north of Rathmullen, a black bed of 
imestone that has been worked as a marble. It, however, is of 
such small dimensions as not to be of commercial value. 


Kinanan—On Irish Marbles and Limestones. 387 


FERMANAGH. 


Carrickreagh, five miles from Enniskillen.—Not a very good 
black, but takes a good polish; has been used greatly for tomb- 
stones. At various other places there are blackish stones, that 
have been locally used, but none of those known are of good or 
even fair quality as black marbles. 


GALWAY. 


The premier black limestones are now supplied from this 
county. 

Angliham and Menlough.—The marbles from these quarries, 
which are situated three miles north of Galway, are world-famed, 
and include some of the best, if not the best, examples of black 
marble ever known. ‘hese were at one time extensively exported 
to London and America, the stone from one bed being all kept for 
the London market, from which it has received the name of the 
London bed. Wilkinson, when writing of these quarries in 1845, 
pointed out that, on account of the eastern dip of the strata, the 
head over the marble beds was gradually increasing, while the 
floor of the quarry was becoming of an inconvenient depth below 
Lough Corrib, both of which circumstances were gradually adding 
greatly to expenses incurred in removing the superfiuous stone, 
and in keeping the quarry dry. In 1868 there were 40 feet of 
clearing over the marble beds. At that time, in the Menlough 
quarry, there were two good beds, one 13 and the other 15 inches 
thick, below flaggy beds, used for tombstones. At thesame time, 
in the Angliham quarry there were three beds, the Thin, 9 inches 
thick ; the London, 12 inches; and the Double, 14 inches. The 
Thin bed was the purest marble, while the 12-inch got its name 
from being kept solely for the London market, preference being 
given to it on account of its capability of being cut most economi- 
cally. The principal markets were London, Liverpool, Bristol, 
and Glasgow. At the present time the clearing and pumping 
have greatly increased, which adds much to the cost of getting the 
stone. 

Merlin Park. About two miles 8. E. of Galway.—In this 


quarry two sets of beds were formerly extensively worked by the 
2D2 


388 Scientific Proceedings, Royal Dublin Society. 


Blakes of Merlin Park, till about the year 1850, after which it lay 
idle till within the last few years, when it came into the hands of 
the Messrs. Sibthorpes of Dublin, who have since worked it, the 
stone being very good, equal to the stone from the Angliham quarry. 
Quite recently, on sinking below the floor of the old quarry, other 
black beds have been found, which appear to be of superior quality ; 
but as yet very little can be said about them, as the surface has still 
to be cleared off. In the quarry there is a clearing of about 25 
feet of rock, the upper 17 feet being loose. Under this are three 
beds of marble, 6, 11, and 15 inches, the two lower sometimes 
forming one, about 2 feet 2inches thick. Below the upper marble. 
are abcut 10 feet of black limestone that lie on three marble beds, 
12, 15, and 12 inches thick, while still lower are the new beds. 

In Gortveragh, north of the Glebe-house, and a mile H. 8. H. 
of Oughterard, there is a fair black stone that was formerly worked 
by the Martins of Ballynahinch. It can be raised in very large 
blocks, but at the present time the stone is not favourably received. 
The old scabbled blocks still le there, the quarry not having been 
worked since the Martins’ time. 

Cregys.—Between the last place and Oughterard there is a bed 
of black marble, spotted with white, which has not been used 
except very locally. It is capable of being raised in large sizes, 
and of taking a good polish. A slab 10 feet by over 5 feet was 
used for the landing at Lemonfield hall-door. 


KERRY. 


Good marbles were formerly obtained at Ballinageragh, five 
miles west of Listowel, and also near Tralee. In recent years. 
trials have been made in these places, and elsewhere, but none of 
‘the stones were considered suitable for the ‘present demand. The 
Kerry stone in general is more or less spotted with white, some of 
it being variegated. 


KOLKENNY. 


Near Archer’s Grove, and about half a mile south-east of the 
town, is the historical Black Quarry, with which has been connected 
the name of Colles for the better part of two centuries. Dr. Ger- 
rard Boate, writing in 1652, mentions :—“ Besides the freestones. 


Kinanan—On Irish Marbles and Limestones. 389 


which is in every part of the land, there is marble found in many 
places, but more about Kilkenny, where not only many houses are 
built of the same, but whole streets are paved withit. The quarry 
- out of which they have their marble at Kilkenny is not above a 
quarter of a mile from the town, and belongeth to nobody in parti- 
cular, lying in common for all the townsmen, who at any time may 
fetch as much out of it as seemeth good unto them without paying 
anything for ites. 5 This marble, while it is rude as it cometh 
‘out of the ground, looketh greyish, but being polished, it getteth a 
fine brownish colour, drawing somewhat toward the black.” 

Boate does not appear to be quite correct in saying it was free, 
as it would appear to have been for years the subject of a suit in 
Chancery, between the families of Jacob and Minchin, from both of 
whom Alderman William Colles took leases in 1737, having a few 
years previously (about 1730) invented machinery, worked by 
water-power, for cutting, polishing, and boring the marble; and 
since that time his descendants have had the sole use of it. Alder- 
man Colles’ works are mentioned in a Tour in Ireland, by two | 
English gentlemen, a.p. 1748, and in Tighe’s Statistical Survey of 
Kilkenny, published 1802; while we learn from a recent inquiry 
instituted by Professor Henry, M. Seely, Middleburg, Vt. U.S. A., 
and published by the Middleburg Historical Society, that Colles 
was the first to apply water power for the polishing and boring 
of marble, using it for cutting being in part a re-invention, as 
in the fourth century of the Christian era stones had been sawn 
hy water-power on the river Roen in Germany. 

The Kilkenny marble quarry proper, the “ Black Quarry,” is 
close to the river, near Archer’s Grove, and about half a mile 8. E. 
of the town ; this is supposed to be the quarry mentioned by Boate, 
and has been worked for at least a century and a-half by the 
Colleses, the great-great-grandfather of the present proprietor 
having been the founder of the Kilkenny marble works for the 
manufacture of chimney-pieces, picture frames, tables, and various 
other articles, by water-power. 

In this quarry there are three varieties: shelly black, pure black, 
and dark-grey. The shelly black is par excellence ‘“ Kilkenny 
marble,” the black, with white shells, being world-famed under 
that name; and in connexion with it was the curious general 
belief, that the stones when first procured are perfectly black, the 


390 Scientific Proceedings, Royal Dublin Society. 


white shells appearing subsequently, being gradually developed 
when the marble is subjected to heat. But Mr. Colles states this 
is a fallacy, as he has never known a case in which this occurred, 
and the fossils are always to be seen from the first. 

The pure black is hard and fine-grained, and makes good 
slabs, a very fine one being in O’Connell’s tomb, Glasnevin, 
Dublin. 

At Sion Hill, opposite, on the east of the river Nore, marble 
was formerly raised, but not of as good a quality as in the Black 
(Wuarry, and has not been worked for thirty or forty years, the 
quarry being now closed up. 

At Butler’s Grove, near Monefelim, north-north-west of Gore’s 
Bridge, there is a very pure black marble, which at the present 
time is worked at the Kilkenny works, while formerly it was in 
great request. 

West of Thomastown is a black stone, but not of good quality ; 
it was, however, formerly much used for tombstones, the heavy 
clearing over it being burnt into lime on the spot, and sold for 
farming purposes; but since the demand for lime fell off the 
quarries, like many others, are nearly idle. 


LIMERIcK. 


Good “blacks” were also formerly procured in this county, 
they being wrought in the quarries, and at the Marble Works, 
Killaloe, on the Shannon, while the best were exported to London. 
There appears to have been beds of different qualities, the most- 
valuable being those which were of even texture and free from 
silex, as the presence of the latter not only made them hard and 

_ costly to work, but also less capable of receiving a polish. 

At Thomond’s Gate, Limerick, a quarry was formerly largely 
worked, the famous “ Broken Treaty Stone” being a rough block 
from it. Under the present railway station there was a large quarry, 
the lowest bed being an excellent black stone fit for the London 
market, and which was worked up to about the year 1830. Over 
two miles from Limerick, at Ballysimon, there were stones of 
excellent quality, some of the best of which were sent to London. 
The beds varied from 7 inches to 4 feet, and 6 feet in thickness, 
the premier bed being one 12 inches thick. | 


Kinanan—On Irish Marbles and Limestones. 3891 


Black marble was also procured at Banks’ quarry and Carey’s- 
road; and when the railway was being made from Limerick to 
Foynes, black marbles were cut at about half-way between 
- St. Patrick’s Well and Adare; also near the margin of the 
marsh between Adare and Rathkeale. 


Mayo. 


In Partry there is a superior stone, but in so small a quantity 
that it does not appear worth quarrying. There is also a fair 
stone near Castlebar, which at present has only been partially 
tried. 


MonaGHAN. 


There is a fair black stone, near Glasslough, which appears to 
have been locally used, but which is not generally known. 


SLIGO. 


In this county black stones, capable of receiving a fair, good 
polish, have been procured in different places, but they appear to 
have been principally utilized for tombstones. 


TIPPERARY. 


Near Dunkerrin, near Portumna Bridge, and at Castle Briggs, 
on the Shannon, beds of marble were formerly worked. Stones 
from the second and third localities were sent by water to the 
Killaloe Marble Works, but they are not now worked. 


WATERFORD. 


Black marbles, which were locally used, are said to have been 
procured at places in the limestones between Lismore and Duu- 
garvan. 


392 Scientific Proceedings, Royal Dublin Society. 


GREY MARBLES. 


[Grey marbles are recorded from the following counties :—Armagh, Carlow, Cork, 
Galway, Kerry, Kilkenny, King’s Co., Limerick, Longford, Tipperary, Waterford, 
and Westmeath. They might be procured in different other places if there was a 
demand for them, but only those with peculiarities are much sought after. Many of 
the so-called reds are more properly clouded greys. | 


ARMAGH. 

In the famous quarry for “reds,” the so-called “‘white marble” 

is a very light, whitish grey. 
CaRLow. 

In the Clogrenan quarry there is a crinoidal, fossiliferous 
stone, somewhat like the famed Clonmacnoise stone, in the King’s 
County. 

Cork. 

The stone at Midleton, although in general classed as one of 

the ‘‘ reds,” is more properly a variegated or clouded grey. 


GALWAY. 

At Angliham, three miles north of Galway, one of the beds 
worked in the “ Black Marble Quarry” is a dark-grey. Near 
Angliham, in Terrylaw, to the N. N. W. of Mr. Carter’s house, 
there is a handsome grey spotted and speckled stone. This has 
not been worked as a marble, but a polished specimen is in the 
Museum, Queen’s College, Galway. 

About three miles from Ballinasloe is a superior dark-grey 
stone, capable of being raised in very large blocks and of receiving 
a fine polish. It was extensively used in Lady Burdett Coutts’ 
markets, London, at East Grinstead, Covent, Chester, &e. 

Various grey stones of the Burren type, in other places in this 
county, are suitable for marble, if there was a demand for “ greys.” 


Kerry. 


In this county trials have been made on “greys,”’ which have 
been found very good ; but on account of their distances from the 
market, and from the fact that stones of this colour are not much 
in request, they have not been utilized, except locally. In colour 
they vary from a clouded light tint, or nearly white, to dark and 
blackish. 


Kinanan—On Irish Marbles and Limestones. 393 


KILKENNY. 


One of the beds worked in the “ Black Quarry,” Kilkenny, 1s 
a dark grey. In the Ballykilaboy quarry, about four miles from 
Waterford, there is a superior stone, capable of being raised in 
very large blocks, 17 feet by 5 feet, and 2 feet thick. 


Kine’s County. 

At the Ballyduff quarry, near Tullamore, there is a very 
superior stone, of grey colour, graduating into a wan dove-colour. 
This has been very extensively used in the locality for chimney- 
pieces and ornamental slabs. It is a beautifully clouded stone in 
places, and seems well worthy of more public notice than it has as 
yet received. 

Near the Seven Churches, Clonmacnoise, are the well known 
fossiliferous crinoidal mottled-grey stones, formerly most exten- 
sively worked at the Killaloe Marble Works, to which they were 
brought by water, and still very much used on account of their 
peculiar appearance. 


LIMERICK. 


bp 


In this county, associated with the “reds,” already enume- 
rated, there are “ greys,” except at Pallaskenry. Some of these 
reds are in part clouded, or spotted grey, or graduate into grey or 
dove-colour. The beautiful stone used in the cloisters at Askeaton 
is, in general, a grey, some parts only being clouded with red or 
other colours. 


LonGForRD. 


At Ballymahon a stone has been raised which, when polished, 
is grey, mottled with red and brown (Kane). 


TIPPERARY. 


Near Dunkerrin there were various trials made for marble. 
‘One stone reported, was pale-grey nearly white; and a second a 
purplish-grey, or dove-colour (ane). 


394 Scientific Proceedings, Royal Dublin Society. 


WATERFORD. 


In the crags between Lismore and Dungarvan there is a light- 
grey, nearly-white stone, capable of receiving a good polish; it is. 
said to have been procured and locally used (Kane). 


WESTMEATH. 


At Hall, three miles 8. W. of Moate, there is a very good 
quality of grey stone, splashed with white. In some there are red 
veins, but this variety is not as sound. It was used extensively 
at the New Exchange, Manchester, in Bradford, and other places 
in England. 


VARIOUS-COLOURED. 


[Various-coloured marbles of Carboniferous age, which cannot be classed with the 
“‘reds,”” “blacks,” or ‘“greys,’’ are recorded from Clare, Donegal, Fermanagh, 
King’s Co., and Tipperary. | 


CLARE. 


At Clondes Lough there is a fine bardilla, or bardiglio marble- 
(Kane), a bluish-grey stone, with irregular fine lines and blotches 
of a dark colour, called originally from Bardiglio, in Italy, where. 
it principally comes from, as pointed out by Colles. 


DonEGAL. 


In Glendowan, westward of Lough Veagh, there is a ribanded 
Sienna-coloured stone, but so thin-bedded as to be valueless as a 
marble. It, however, takes a good polish. 


FERMANAGH. 


In a hill between Castle Caldwell and Belleek is a pale-grey 
crinoidal limestone, with red spots and circles, due to scattered 
crinoid stems that are stained with iron. A pillar of it is in the 
Museum of Trinity College, Dublin. 


IE On Irish Marbles and Limestones. 395: 


Kine’s Co. 


Near Clonmacnoise, Wilkinson records “a beautiful marble of 
Sienna character.” It is easily worked, and has been frequently 
used for ornamental works, and ‘deserves to be more generally 
known than it at present is.’ This stone, although of Sienna 
character, is not of Sienna colour, it being more of a purplish- 
clouded grey. 


TIPPERARY. 


Among the marbles mentioned by Kane as occurring near 
Dunkerron are some of yellow colour, and veined. 


METAMORPHIC ROCKS. 


The rocks next to be enumerated are probably metamorphosed 
Ordovicians (Cambro or Lower Silurians) or Cambrians, generally 
the latter. 

These marble-bearing stones must be subdivided, as one class 
was originally limestone or dolomyte, while the other was volcanic 
rock, exotic rock, or those allied to them. The latter have to be 
included, because, as previously pointed out, they, and also certain 
peculiarly altered limestones and dolomytes, are generally classed 
together under the common name of Serpentine, both the lme- 
stone and volcanic rocks having undergone a secondary change, 
due to a chemical action from without, which has been called by 
Dr. King, of Galway, Methylosis. The limestones that have only 
undergone simple metamorphosis (mineralized and micaised) will 
be classed as metamorphic limestones; while the chemically changed 
limestones and exotic rocks will be grouped together. 

The subdivision of the Methylotic rocks is of such recent date 
that, from the available records, it is hard to accurately sub- 
divide them unless all the localities were personally revisited. The 
subdivisions given hereafter are therefore in part only suggestive ; 
but, as far as possible, they will be correct. 


396 Scientific Proceedings, Royal Dublin Society. 


In the list will have to be mentioned rocks that are not at 
all likely ever to be of commercial value as marbles. This, how- 
-ever, appears necessary, as some of them have already been given 
a greater value than they deserve; and, on this account, it is desir- 
able to mention them. 

All of these stones, that are also suitable for cut-stone purposes, 
-are a second time mentioned in the lists of the limestone quarries. 


METAMORPHIC LIMESTONES. 


The rocks that come under this class—with the exception of 
the peculiar Sienna-coloured stone in Glendowan, the black stones 
from near Rathmullen, Co. Donegal, and those of Carricksheedy, 
Co. Londonderry—are white, or shades of white, some handsome 
stones being tinted or clouded with grey, pink, or green. All are 
more or less schistose. Some are thin-bedded, those that are 
massive generally rising in more or less rude, unshapely blocks. 
The stones are for the most part coarsely crystalline, and conse- 
‘quently not able to compete with the Italian stones; while those 
of a creamy character, as far as has yet been discovered, are also 
disqualified, owing to their being either too thin-bedded or jointy, 
which prevents them being raised in blocks of sufficient size. 

On this account many hand-specimens show a beautiful stone 
equal to any elsewhere; while, in the quarry, these stones are 
found to be of such small dimensions as only to be suitable for 
the manufacture of articles of vertu. 

This to me seems a most important fact, to which too much 
attention cannot be directed in Papers on the Economic Geology 
of the country. 

What might be highly productive industries have been already 
destroyed by false statements in reference to them. 


Kinanan—On Trish Marbles and Limestones. 397 


WHITE and RED MARBLES. 


[Sometimes tinted, or clouded, with grey, pink, or green; in general coarsely” 
crystalline ; rarely fine-grained and compact-] 


DoneEGAL. 


In the promontory of Fanad, north of Kindram Lough, and 
immediately west of Lord Leitrim’s lodge, is a white stone, partly 
coarsely crystalline and in part compact. It has not been opened 
into; but a specimen from the surface gave unsatisfactory results. 

Immediately east of the south arm of Sheephaven, in the 
townland of Drumlackagh, is a considerable thickness of limestone 
of white to grey tints, some of it being massive, the rest flaggy. 
Its qualifications for marble have not been tested. 

To the eastward of Dunfanaghy, at Marble Hill (Glaisheen), | 
the stone is white or rose-tinted. It is capable of receiving a good 
polish—crystalline and slightly schistose. 

At Ballymore, four miles from Dunfanaghy, there is a creamy- 
white stone, in places clouded with brown or having brown por-- 
tions. It polishes well, and has been worked as a marble of a 
pleasing character. 

At Kinclevin, nearly a mile from Dunfanaghy, there is a 
greyish-white stone not very promising. 

Lewis mentions a superior “ white marble” in the Rosses, 
“capable of being raised in large blocks.” This ought to be some- 
where to the north of Gweedore; but the locality has not been 
satisfactorily localized. 

Six miles HE. 8. E. of Gweedore Hotel, at Dunlewy, there is a 
large limestone quarry. ‘The stone is white to creamy-white, 
tinted with green and pink. It has been used both as building- 
stone and as marble. ‘The “ whites” are coarse, but durable; the. 
others are beautiful stones, but so thin-bedded and jointed that it is 
impossible to raise them, except in pieces of small dimensions, which 
renders it of little commercial value. As the quarry has been 
worked only along the surface of the bed, rarely twenty feet deep, 
it is possible that better stones might be got at some depth, espe-- 
cially at the western end. 


398 Scientific Proceedings, Royal Dublin Society. 


At the base of the range of hills north of Fintown are white 
limestones favourably reported on. No trials, however, have been 
made on them. 

A little south-east of Glenveigh Castle, a surface trial was made 
‘on a white, highly crystalline limestone. HKnough of it is not seen 
to form an opinion; but the rock appears worthy of making a more 
extensive opening on it. 

In the parish of Gartan, on the west shore of Lough Akibbon, 
and two miles north of Church Hill, is a white, greyish, and 
pink-tinted stone. It polishes well, and has been approved of by 
the marble-workers ; but further and more extended trials are 
necessary to prove whether it can be raised in blocks of profitable 
size. 

In the townland of Magheranan, to the east of Letterkenny, 
is a nice-looking white stone, spotted with green, that has not been 
opened up, and its qualities are unknown. 

In the hills north-east of Kilmacrennan, near the village of 
Ardanawark, are white and pinkish rocks that can be raised, it is 
said, in large-sized blocks. No trial has been made on them; but 
a specimen polished easily and well. They appear to be in the 
same beds as those at Lough Akibbon. 

Three miles south-east of Letterkenny, in Magheraboy, is a 
nice-looking, white, untried stone. 

About a mile east of Convoy, at Kiltale, there is a white stone 
of good appearance, but thin-bedded. 

In various other places in the gneiss district (Cambrian) of 
Donegal are small detached masses, or beds, of white, or clouded- 
white crystalline limestones; but as none of them seem to be of a 
magnitude or quality to form a “quarry,” it appears unnecessary 
to enumerate them. 


GALWAY. 


To the south of Letterfrack, in the hill of Creggs, are, white 
limestones. One portion is a stone of “excellent quality, equal to 
the Italian, but it rises in small blocks” (Sibthorpe). After some 
time spent in sinking on this vein, Dr. Ritchie of Belfast failed in 
getting good-sized marketable blocks. 

On the western shore of Derryclare Lough there is a quarry, 
formerly worked by the Martins of Ballynahinch, who seem to 


Kinanan—On Irish Marbles and Limestones. 399 


have raised some fair-sized blocks; colour white, tinted with grey. 
In the lake in White Island there is a very peculiar stone, white, 
spotted with green Serpentine crystals. This rock is associated. 
_ with green ophialyte ; no opening has as yet been made in it. 

South of Adrehid Lake, and in a second place, to the westward 
of Glengowla Mine, both a little west of Oughterard, there are 
white crystalline rocks, that have not been tried as yet. 

There is also an untried fair-looking white limestone north-west 
of Ross Lake, between Oughterard and Galway. 


Loutu. 


In the Carlingford promontory white crystalline limestones 
have been found in three places, but of such limited extent, that it 
seems improbable that they should ever be of commercial value. 


SIENNA-COLOURED. 
DOoNEGAL. 


In Glendowan, westward of Lough Veagh, I‘Henry records a 
ribanded Sienna-coloured stone, that polishes well, but it is too 
thin-bedded to be of much value. Its layer there is a structure 
like Hozoon canadense. 

GALWAY. 


At Lough Auna there is a maculated Sienna-coloured stone of 
limited extent (see page 402). 


BLACK MARBLE. 


[Black stones in the metamorphic rocks fit for marbles are only recorded in the 
Cos. Donegal and Londonderry. | 


DoneEGAL. 


At Kintale, a mile and a-half north of Rathmullen, Kane 
records a stone capable of being used as a marble. It appears to 
be only very locally known. 


LonDONDERRY. 


At Carricksheedy there is a black stone capable of taking a 
good polish; it appears, however, to be only locally known. 


400 Scientific Proceedings, Royal Dublin Society. 


METHYLOTIC ROCKS, or SERPENTINES. 


The name Serpentine is more applicable to the methylotic lime- 
stones than to the methylotic volcanic rocks. We will, however, 
here use it in the broad popular sense, and include under it all the 
methylotic limestones and volcanic rocks, also the rocks allied thereto- 
Of late years Lithologists have greatly subdivided these rocks, the 
principal subdivisions of the former being called ophiolytes, ophi- 
ealcytes, and ophidolomytes ; and of the latter, ophyte and eklogyte, 
with the allied rocks steatyte (soap-stone) and pyrophyllyte (cam- 
stone). 

Dana divides the massive Serpentine or ophyte into precious 
Serpentine of a rich old green colour, of pale or dark shades, and 
translucent, even when in thick pieces; and common Serpentine of 
dark shades of colour, and subtranslucent. The latter is hard 
and difficult to work on account of impurities. Many statues 
however, in Egypt and India are made of rocks of this class. Hklo- 
gyte is still commonly called Serpentine. Formerly steatite and 
pyrophyllyte were also thus classed; now many separate them. 
Steatyte and pyrophyllyte are still confounded together by most 
‘people, their appearance being very similar; yet they are chemi- 
cally very distinct, the former being a silicate of magnesia, and 
the latter a silicate of alumina. Steatyte seems to be always an 
adjunct of volcanic rocks, while the other occurs in general as a 
bedded rock: steatyte, however, may occur as “fault rock,” if the 
latter had been made up of volcanic rock debris or volcanic tuff. 


METHYLOTIC LIMESTONES ann DOLOMYTHS. 
OPHIOLYTES, OPHICALCYTES, and OPHIDOLOMYTES. 


The rocks of this division now of commercial value are recorded 
only in the west of the Co. Galway, and are known as Connemara 
_ greens. They have indeed been found also in the counties Donegal 
and Waterford, but from neither of these counties do any stones 
come intothe market, while the beds or veins seem to be so limited 
in extent that there does not appear much prospect of their ever 
doing so. 


Kinanan—On Irish Marbles and Limestones. 401 


The “Connemara greens” are most varied in colour. Some are 
dark-green, uniform, or clouded; others are leek green or light 
green ; while the majority are mottled or spotted, or streaked and 
_ variegated. These last are very happily described by Sir C. L. 
Giesecke, who wrote near the beginning of the century. “It is im- 
possible to describe the immense varieties of delineations and shades 
and colours of the beautiful stone which attracts the eyes of the 
beholder; the serpent-like (i. e. wavy formation) delineation of 
some of them must excite particular admiration. Others are coloured 
in spiral forms; others are dotted and spotted with different shades 
of grey and yellow.” 


GREEN, or VARIEGATED, or STREAKED with GREY, 
WHITE, RED, YELLOW, PURPLISH. 


GALWAY. 


The ophialites occur in one group of strata which were once 
continuous, but now, on account of the breaking-up of the rock 
by faults, the exposures are more or less disconnected and iso- 
lated. The most northern exposure occurs as an isolated mass 
at Loughnagur range, two miles south of Barnaderg, or Ballyna- 
kille Harbour. The rocks are uniform, clouded, and variegated 
green. The stone has not been worked in this locality. The nearest 
harbour to itis Barnaderg, with which it might easily be connected 
by a road. 

At the west end of Streamstown Bay, or about two miles north 
of Clifden, are different exposures of ophicalcyte. On a vein a little 
east of the end of the bay is the quarry formerly worked by the 
D’Arcys of Clifden, and of late years by Mr. Colles of Kilkenny. 
The stone in general is variegated with spots or streaks; green, 
grey, and white predominating. The scabbled blocks are carted to 
Clifden for shipment. 

In the eastern continuation of the Streamstown Bay valley, 
occupying a narrow tract over three miles long, which extends from 
Loughauna to Loughnahillion, is anearly continuous band of these 
rocks. Here there is a great variety, both in beauty and colour, as 


1 Trans. Royal Dublin Society, vol |xii., March 2, 1826, Appendix. 
SCIEN. PROC, R.D.S.—VOL. V. PT. v. 2E 


402 Scientific Proceedings, Royal Dublin Soctety. 


exhibited in the ornaments manufactured by the M‘Donnells of Clif- 
den—self-taught artists—who manufacture brooches and various 
other articles of vertw by hand, out of ophialytes from these and 
all the other localities, to dispose of them to visitors. One unique 
and beautiful variety on sale by Alick M‘Donnell was a maculate 
Sienna-colour ophialyte from a vein at Loughauna. To work the 
stone in this valley, that to the westward, near Loughauna, 
could best be approached by a road constructed from Streamstown 
Bay, from where it could be carted to Clifden for shipment; while 
that at Loughnahillion would be brought more easily by a road 
northward to Barnaderg Bay. 

To the south and south-eastward of the valley last mentioned, 
and nearly parallel to it, is that of the Owenglin; where, in 
occasional spots for a distance of over three miles, the ophialytes 
appear. They are, as elsewhere, most varied in colour and beauty, 
while in some of the streaked varieties the structure that has been 
called Hozoon canadense occurs. In this valley, at Barnaoran, are 
the famous “ Ballynahinch Marble Quarries,” from which, in old 
time, most of the Connemara marble was obtained ; and it was of 
the stone seen here that Geisecke wrote. Of late years these 
quarries have got into disrepute, on account of the severe road 
from them, a steep ridge intervening between Owenglin and Bally- 
nahinch, over which the blocks had to be carted. This stone was 
used in the new Museums at Oxford and Trinity College, Dublin. 
A small vein of a peculiar variety (Onkosin) occurs to the east of 
Barnaoran ; it is of a pale olive greenish grey colour, full of den- 
dritic markings, and having an appearance somewhat like moss 
agate. ‘This, under the name of “moss serpentine,” was exten- 
sively worked by Alick M‘Donnell, who discovered it. A very 
fine specimen is in the Museum, Queen’s College, Galway. 

The blocks of stone from this valley have to be drawn across 
the ridge to the Ballynahinch valley, and from thence to Cloonisle 
pier for shipment; they might, however, be manufactured by 
water power at the quarries. 

Extending southward, at nearly a right angle from the east 
end of Owenglin, is Glenisky. Here the serpentine occurs in 
veins that continue southward from those in Owenglin, along the 
western slopes of Bengower, past the summit of Benlettery, termi- 
nating on the south slope of the latter. The stones are very similar 


Kinanan—On Irish Marbles and Limestones. 403 


to those in Owenglin, but with them are also found smaragdite 
schist. The place is difficult of access; because Glenisky, leading 
down to Ballynahinch, is steep and rugged. Blocks might, how- 
ever, be run down an incline, or the marble might be worked in 
the glen by water-power. The south end of the glen is about five 
or six miles from Cloonisle pier. 

In the south-east slope of Benlettery there is the small east 
and west valley called Derrynagloan, where there is a small vein. 
This is of easy access from the Ballynahinch road. 

Extending northward from the east end of Ballynahinch lake 
is Glencoaghan. Here are found, in different places, detached 
exposures of serpentine, the largest occurring at, and southward of, 
Bennaderreen, on the western slope of Derryclare hill. The other 
exposures are between this and the lake. The stones are very 
similar to those in Glenisky. No quarry as yet has been opened ; 
nor is there a cart road into the glen, but one could easily be con- 
structed, which would pass by all the exposures. Canal Bridge, at 
the mouth of the valley, is about seven or eight miles from 
Cloonisle. 

Veins of serpentine occur in places along the north-east portion 
of the south-east ‘shore of; Derryclare lake, and also in the islands. 
Here, especially in White Island, the rocks appear to be more 
varied in colour than elsewhere, one being very peculiar, having 
in a whitish ground long, erystal-like pieces of dark green. Most 
of the veins are at the water level, and, if they were worked, there 
would be a certain amount of expense in pumping. The blocks, 
however, might be carried by water down the lake to Canal 
Bridge, and even down Ballynahinch Lake to the river near 
Toombeola,{ where they would be only a short distance from 
Cloonisle. 

Farther eastward, to the northward of the Recess Hotel, on 
the south-west and north-west slopes of Lissoughter, are various 
detached exposures of serpentine. On the south-west slope, close to 
the village, is a quarry formerly worked to a slight extent by the 
Martins of Ballynahinch, but much more extensively during the 
last fifteen years bythe Messrs. Sibthorpe of Dublin. This stone 
is, in general, uniform, or clouded green, some being dark, but 
at the same time translucent. Very good-sized stones have been 


raised, but in rough, unshapely blocks. The stone, however, is of 
2H 2 


404 Scientific Proceedings, Royal Dublin Society. 


such good quality, that it has been found more profitable to carry 
them unsquared to Cloonisle for shipment than to square them in 
the quarry. 

At the time the Messrs. Sibthorpe began working, about the 
year 1870, there was a considerable demand for ‘“ Connemara 
greens”; but unfortunately for the reputation of the stone, as 
also for many other marbles, architects would insist on using them 
in outside decorations, and, consequently, not through any real 
inferiority in the stones, they soon weathered and became un- 
sightly. Thus was generated a most undeserved prejudice against 
the green marbles, which, when used in their proper sphere as 
inside work, cannot be surpassed in beauty or elegance. 

The largest column yet obtained (9 ft. 9 in.) was wrought 
out of a block raised in Lissoughter. It is now at St. Anne’s, 
Co. Dublin, the mansion of Lord Ardilaun. In England this 
marble was used at the Manchester Exchange, Rochdale Town 
Hall, St. Mary, and other places in Bradford; St. John’s College,. 
Cambridge; St. Mary Abbot’s, Kensington; St. Pancras Hotel 
and Station, &e. Recently it is being exported to America, there 
being a greater demand for the uniform and clouded dark-greens 
than for any of the others. From either the Lissoughter or Bar- 
naoran quarries was procured the serpentine, by the Martins of 
Ballynahinch, that was wrought into the chimney-piece presented 
to George IV., and now in the Carlton Club, London. 


METHYLOTIC EXOTIC ROCKS. 
(Opnyrr, Exiocyte, SrEatyTE, AND PyRroPHYLLYTE.) 
DARK-GREENS, and VARIEGATED. 


The ophytes, as a general rule, may be classed as “ dark- 
greens,” although some are of light colours, or spotted, mottled, 
and streaked. None of them appear to answer fully Dana’s defini-. 
tion of “ Precious Serpentine,”’ as they seem in general to occupy 
a position between that grade and his “Common Serpentine.” 
None of them are in the market, although they are equal to, and 
perhaps even surpass, some of the foreign stones. 


Kananan—On Irish Marbles and Limestones. 405 


They are not, comparatively, of rare occurrence, being recorded 
in seven counties, while probably they will be found in others, as 
until recently it has been customary to group them with the 
associated pyroxenic or other volcanic rocks, of which they are 
methylotic adjuncts. Thus, in the counties Wexford and Wick- 
low, it is only recently that these distinct rocks have been separated 
on the maps. 

As far as the records can be depended on, these rocks are, in 
almost all cases, found associated with the old metamorphic rocks 
(Ordovician and Cambrian). One exception, however, has been men- 
tioned, as ophyte is found as an adjunct of the Carboniferous rocks 
of the Co. Limerick. Here the tract is of such small dimensions 
and the rock so inferior in quality, that it might be ignored were 
it not for the exceptional circumstances under which it has been 
found. It is quite possible, however, now that attention has been 
called to the circumstance, that it may be found elsewhere associ- 
ated with even younger rocks. 

Eklogyte is in aspect very like ophyte, and by most geologists 
they are classed together. It has therefore been only recorded in 
two counties, although probably it also occurs elsewhere. It is 
allied more or less closely to saussuryte, or Swiss jade. Some of the 
ancient implements known under the general name of “celt” 
were manufactured out of rocks of this class. 

The steatytes or soapstones are in colour very pale-grey, or 
bluish, or greenish, or greyish-white, while others are reddish or 
orange. Some of them are very suitable for the manufacture of 
articles of vertu, but as far as we are aware they have not been so 
utilized. 

Pyrophyllyte or camstone may be counted as a new class of 
rock ; for although given its proper place in mineralogical books, 
in geological writings it has almost invariably been called steatyte, 
or a “coarse variety of steatyte”; consequently the records of its 
occurrence are few. For years it has been recognized in the Co. 
Donegal, and has been used in some of the ecclesiastical structures. 
A. rock that appears to be pyrophyllyte is also recorded in the 
Co. Cork; while patches and veins or beds occur in the blackish 
slates of Ordovician age in the Co. Wexford. In other places, if 
it exists, it has been classed with steatyte. It probably occurs in 
the Co. Galway, as hereafter mentioned. 


406 | Scientific Proceedings, Royal Dublin Society. 


OPHYTES. 


[Dark-green to blackish, some striated and spotted. Occur in the Cos. Galway,. 
Mayo, Sligo, Tyrone, Waterford, Wexford, and Wicklow. ] 


GALWAY. 


To the north of the townland of Leamnaheltia, near the south 
shore of Lough Fee, in the mountainous tract north of Kylemore 
Lough, is an isolated mass of ophyte of dark, and in places lighter 
clouded greens. Some pieces of this rock were worked by Alick 
M‘Donnell of Clifden, who stated “the rock was very kind.” 

At Dawros, to the east of Ballynakille Harbour, and a little 
north of Letterfrack, there is an extensive tract of dark-green, 
nearly black, ophyte. 

To the south and south-west of Garroman, or Glendollagh 
lake, are small tracts of dark-green ophyte. 

Near the shore of Galway Bay, about half a mile south-west of 
the ruins of Bunowen Castle, is a small tract of dark-green, nearly 
black, ophyte. 

In the mountainous tract of Errisbeg, to the westward of 
Roundstone, are three rather long tracts of ophyte. Two are 
near Lough Bollard, while the third is a little more than half a. 
mile to the east of it. The stone in general is dark-green, but 
some of it is mottled, dark and light. 


Mayo. 


Two miles north of Castlebar there is a long narrow exposure- 
of dark to light-green ophyte. 

Along the northern slope of the Croagh Patrick range, from 
near Louisburg to some miles east of Westport, is a long wide 
tract of ophyte associated with steatyte. To the westward it thins 
out, while its greatest thickness appears to be at the railway cutting 
a, mile and a-half south-east of Westport. Some surface-specimens. 
were experimentalized on and were found difficult to cut; but it 
might improve if opened in depth; it appears worthy of trial, as it 
varies much in colour, from greenish-black to dark-green, light- 
green, reddish, and purplish ; some of it being handsomely streaked. 
with the colour last mentioned. 


Konauan—On Trish Marbles and Limestones. 407 


In the hills between Leenaun and Wesport, two or three miles. 
north-west of Sheffey, at and south-west of Lugaloughaun, are 
three or four exposures of a peculiar rock that appears to be allied 
to ophyte; they are of different shades of light green. These 
rocks work easily, but it is questionable if they could be procured 
in large blocks. The place at present is very inaccessible. 

In Glencullin, north-east of Mweelrea, is a dyke of mottled- 
green rock allied to ophyte, or eklogyte (?). 


S1iao. 


At Slishwood and the valley running nearly south from Bun- 
owen Bay, Lough Gill, ‘is a band nearly two miles long and about 
five hundred feet wide, of a dark-coloured, compact, somewhat 
hard ophitic rock. It contains magnetite, especially to the west- 
ward, where Hardman states it ‘‘ possesses all the characters of 
natural magnets.” It also contains some nickel. The rock is of 
a splintery nature. Although called a serpentine, it possibly more 
correctly should be classed as an eklogyte. 

At Drumahaire, three miles north-east of the Slishwood ser- 
pentine, there is a band about three hundred feet thick of very 
similar rock, except that it is not ‘“‘ perceptibly magnetic.” 

Close to Shanavan’s Bridge, near Manorhamilton, is a third 
band of similar rock, supposed to be about a mile long. 

In the Geology of Ireland, p. 191, it is suggested that these 
rocks were possibly metamorphic Cambrians or even Laurentians. 
It now, however, appears to be much more probable that they are 
in part Cambrian, and in part Ordovician.* 


TYRONE. 


Westward of Cookstown, to the north and north-west of 
Pomeroy, are the hills in which Slieve Gallion is the principal 


1 If the markings found near Lough Finn, Co. Donegal, and exhibited by Dr. Hull 
at British Association Meeting, 1886, are graptolites of Arenig types, as appears to 
be very probable, the supposed Laurentians of Donegal are unquestionably metamor- 
phosed Ordovicians, Arenigs, and Cambrians. Consequently, it is probable that the 
rocks of Sligo, and also the similar rocks of Cos. Tyrone, Leitrim, and Mayo. are also 
Cambrian, Arenig, and Ordovician. 


408 Scientific Proceedings, Royal Dublin Society. 


summit. These, for the most part, are composed of highly altered 
rocks that have been suggested to be of Laurentian age; but, as 
previously mentioned, are more probably metamorphosed Arenig. 
In them, towards their south margin, are tracts of ophyte, gene- 
rally dark olive-green, approaching to black, but some are of 
lighter colour or variegated or streaked. 

About three miles north-west of Pomeroy, west and south- 
west of the lake that lies half a mile west of the summit of 
Oregganconroe, are four distinct patches of ophyte; while a little 
to the west, on the hill called Scalp, is a fifth. At Athenree, 
about a mile and a-half S.S.W. of Scalp, and a mile south-east 
of Carrickmore or ''ermon rock, there is also a tract, and another 
about half a mile W.N.W., of Carrickmore. In the last, the rock, 
in places, has a decided variegated or streaked colour. Some of 
these stones have a good appearance, and seem to be qualified 
to produce a marble. As yet, none of them have been utilized or 
even tested. 


‘WATERFORD. 


In this county the serpentines recorded are only of very small 
extent. As, however, the rocks of the eastern portion of the 
county are similar to those of the adjoining counties of Wexford 
and Wicklow, and as among the latter ophyte only recently has 
been recorded, it formerly having been included among the 
pyroxenic rocks, it seems not improbable that here, as in Wicklow 
and Wexford, there may be small tracts of ophyte still unrecorded. 
This, however, has still to be examined into. 


WEXFORD AND WICKLOW. 


The presence of ophyte was not recorded in these counties 
until within the last five years, although “ serpentine” is mapped 
on the old geological six-inch maps. This, probably, is due to the 
fact that, until recently, many geologists classed them with the 
pyroxenic rocks, of which they are metholotic varieties. They are 
now known to occur in the following localities :— 

On the north and south slopes of the western spur, extending 
from Croaghan Kinshella, in the townlands of Cummer, Cummer- 


Kinanan—On Irish Marbles and Limestones. 409 


duff, and Hillbrook, some of them being on the borders of the 
counties of Wexford and Wicklow, are detached exposures of 
ophyte. They are of various shades of green, generally dark- 


~ coloured. 


South-west of the spur of high ground last mentioned, and a 
little west of Carnew, in the Co. Wicklow, there is a tract of 
dark-green ophyte, in places spotted with red, like a bloodstone. 
It is capable of taking a good polish. 

Much further northward, about half way between Anamoe and 
‘Togher or Roundwood, is a large boss of dark-green ophyte. 


EKLOGYTE. 


[Speckled and mottled, green and brown, recorded from Galway, Mayo, and Sligo.} 


GALWAY. 
To the W. N. W. of Kylemore Castle, in the townland of 


‘Currywongaun, there is a vein of greenish-brown speckled eklo- 
gyte. A small opening was made by Mitchell Henry, M.P., who 
had some of the rock cut and polished at his saw-mill. 

A little south of Garroman or Glendollagh Lake, in the mass of 
ophyte previously mentioned, is a pipe vein of spotted bright-green 
-eklogyte. 


Mayo. 


A little south-west of Ballyhean, on the north slope of Tona- 
-derrew, there is a mottled light-green eklogyte. The rock in this 
locality is very like the previously-mentioned rocks near Luga- 
loughaun and in Glencullin (see Ophytes, page 406), and it is pos- 
sible that the rocks in these places should be classified with the 
-eklogytes, and not with the ophytes. 


SLIGO. 


The rocks previously described among the ophytes, at Slish- 
wood, Drumahair, and near Manorhamilton, seem to partake very 
much of the nature of eklogyte, and possibly ought to be so 
classed. 


410 Scientific Proceedings, Royal Dublin Society. 


STEATYTE, or SOAPSTONE. 


[Some are pale-grey, of bluish and greenish tints; others reddish or orange. They 
have been stated to be found in the Cos. Donegal (?), Galway, Mayo, Sligo, and! 
Waterford. As the question of the classification of steatyte and pyrophyllyte is 
still obscure, rocks said to be steatyte will be mentioned under this heading, coupled. 
with the objection to their classification. ] 


DoNEGAL. 

In different places associated with the basic volcanic rocks are- 
seams of steatyte, but of very small dimensions. In other places, 
the rocks that are generally called steatyte are more probably 
pyrophyllytes. No large mass of true steatyte appears to be re-- 
corded in the Co. Donegal. 

Near Crohy Head, westward of Dunloe, Mr. Blake states. 
there is a steatyte so pure as to be valuable for the manufacture 
of lubricators. It occurs as a bedded rock unassociated with 
intrusive rocks, and is probably a pyrophyllyte ; but this has still 
to be verified. 

Eastward of Dunfanaghy, at Ards, steatyte is also said to have 
been found. The rock, however, appears to be pyrophyllyte. 


GALWAY. 


Steatyte occurs in subordinate veins and patches, associated. 
with many of the intrudes, especially the ophyte; but they are of 
small dimensions. It has also been recorded as found near Kil- 
meelickin chapel, in the Maum valley. The specimen, however, 
would suggest that the rock was a pyrophyllyte. 


Mayo. 


’ On the south shore of the island of Bofin and the north shore , 
of the island of Shark, in this county (but off the coast of Galway), 
are considerable tracts of fine light to darkening-grey steatyte ;. 
the better portions being of a silver-grey. On Bofin it has been 
worked to some extent, and exported for the manufacture of lubri-- 
cators, but apparently not for articles of vertu. 

In the mountainous tract between the Killary and Clew Bay, 
to the westward of Doolough, there is a considerable mass of an. 
impure yellowish steatyte, an adjunct to a felstern intrude. 


Kinanan—On Irish Marbles and Limestones. 41} 


Associated with the long ophyte mass of the Croagh Patrick 
range, there are steatytes of greater or less extent in different 
places. 


WicKLow. 
To the eastward of Croaghan Kinshella, in the townland 
of Killahurla, there are in places dykes of a reddish or orange: 
friable steatyte. None of these have been opened in depth. 


PYROPHYLLYTE, or CAMSTONE. 


[Pale greyish-green to dark-green. When cut and polished some are of a rich 
olive-green. They are only recorded in the Cos. Cork (?), Donegal, Galway (?), and. 
Wexford. | 


Cork. 

In the carboniferous slate, to the south-west of Castletown 
Berehaven, are beds or dykes of a pale-yellowish stone that are 
probably pyrophyllyte or an allied rock; they, however, require 
further examination. 


DoneEGAL. 


In this county camstone appears to have been recognized for 
years, although in the records it has been called “a coarse or 
impure kind of steatyte”; and has even been mined and sent into 
the market as steatyte. Years ago it was used for architectural 
purposes, as in the ancient churches of Balleekan and Jullydonnell 
south and north, respectively, of the western arm of Lough Swilly,. 
where, when the Old Sandstone mullions of the windows decayed 
away, they were replaced by new ones cut out of camstone. In 
Balleekan there are also tombstones of a somewhat similar class of 
rock. Where this stone was procured is now unknown. Wilkin- 
son, writing in 1845, states that in the mountain range, near Kil- 
macrennan and Barnagh are camstones that “ can be cut or turned 
with facility into any form,” and “are very durable,” but the loca- 
lities are not given, and no quarries in this stone appear to have 
been worked for years, or can now be pointed out in those neigh- 
bourhoods. It is, however, known to occur in the following 
places :— 

About two miles N.N.W. of Castlefin, at Gibbstown, is a quarry 


412 Scientific Proceedings, Royal Dublin Society. 


from which camstone appears to have been procured rather exten- 
sively informer years; at present it is only raised to be used for — 
hearths or the backing of fire-places. 

In places between Raphoe and Letterkenny camstones heme 
been found, but they seem to be only used for local purposes. 

In the townland of Cabrabrook, E.S. EH. of Church Hill, is a 
camstone that appears to have been quarried formerly, but for 
years the quarry has been filled up. 

In Carrowtrasna, west of Lough Akibbon, and over two miles 
northward of Church Hill, is a bed that has been mined by Mr. 
Duckworth for some years, and sent to Liverpool, to be used in the 
manufacture of lubricators; but on his death a few years ago the 
industry was abandoned. 

Beds of camstone associated with limestone can be seenin dif- 
ferent places in the hill country westward of Kilmacrennan, but it 
does not appear to have been worked recently except to get clay for 
hearths. At Cloonkilly there was a large working ; it is probably 
the locality referred to by Wilkinson 

There is a bed or beds to the north and north-east of Ramelton 
and in the neighbourhood of Carn it has been worked along the 
surface to obtain fireclay. 

Westward of Rathmullen, in the townland of Meenreagh, there 
is a bed of camstone. 


LIMESTONE QUARRIES. 


[The quarries will be arranged in the counties placed alphabetically under their 
geological group. Generally only the quarries that give stones fit for cut-stone 
purposes will be mentioned, except in counties where limestone for burning is scarce, 
under which circumstance all the localities are given. In some localities, where 
-quarries are scarce or altogether absent, limestone boulders are found in the drift, and 
are collected along the sea-coast, river, and streams; while in other places sea-shells 
-are carried inland and burned. Tradition says that lime made from sea-shells was used 
as a medicine. | 


ANTRIM. 

In this county there is no Carboniferous limestone except what 
occurs as subordinate beds in the Ballycastle coal-field ; and in 
these no quarry of any note seems to have been worked. 

The Cretaceous, or White Limestone, occurs round the margin of 


KinaHan—On Irish Marbles and Limestones. 413: 


the great field of Cainozoic dolorytes, principally near the coast-line. 

Many quarries have been opened in it, generally to procure stones 
for lime. As the White Limestone is for the most part full of irre- 

gular cracks and joints, it cannot be finely tooled or procured in 

large blocks; it can, however, be scrabbled into fair-sized stones. 
suitable for rough building. A house built of the White Lime- 

stone, with quoins and dressing of the black doloryte, has a clean 

but quaint appearance. 

In pre-historic times the chalk flints were extensively manu- 
factured into weapons and other articles in the county, or were 
exported into the neighbouring counties. Subsequently they were 
manufactured into gun-flints. The latter trade has now died out, 
although still found profitable in parts of England. 

The white limestone in general gives a good and cheap lime. 
It is largely quarried, and exported to the opposite coast of Scotland 
for the purpose of burning. 

At Larne and Glenarm the white limestone is extensively 
manufactured into whiting. 


ARMAGH. 


A limited tract of Carboniferous limestone occurs across the north 
portion of the county. In general it is of an earthy character, in- 
clined to be shaly, and blackish-grey in colour, except at Armagh. 

Armagh.—Light pinkish grey, yellowish, and shades of red. 
This stone, when polished, gives out a warm yellowish colour; but 
when dressed. with the tool it is whitish. It is used as marble, and 
both for rubble and cut-stone purposes. Blocks of large size, 
suitable for columns, have been obtained, while the thinner beds of 
red shades have been made into chimney-pieces and other orna- 
mental work. Formerly these quarries were very extensively 
worked (see Armagh Marbles). 

Navan. A mile from Armagh.—Dark, dull, grey, earthy; 
rather difficult to work. 

Excellent lime isabundant at Armagh, anda good lime, made 
from the white limestone of Co. Down, in the neighbourhood of 
Lurgan and Moira, is also much used. 

At Benburb, adjoining the Co. Tyrone, there is a compact blue 
stone that makes hydraulic lime. It was used in the construction 
of the Ulster Canal. 


414 Scientific Proceedings, Royal Dublin Society. 


CaRLOow. 


In this county the greater portion of the Carboniferous lime- 
stone is a dark iron-grey dolomyte, of a frail nature. Near the 
town there are limestones of the Calp type, some of them being in 
good blocks. The quarries in the latter locality have been worked 
more for the marble than for building-stones. These quarries 
have been already mentioned (see Black Marbles). 

Brownhill. A wile north-east of Carlow.—The stone in general 
is dolomyte, full of drusy cavities (geodes); but one bed, between 
4 and 5 feet thick, consists of grey, compact, and fine-grained 
stone, capable of being dressed. 

In general, the limestone of the county burns into excellent 
‘lime. 

CAVAN. 

Very little good limestone for building purposes can be ob- 
‘tained, except at the extreme south of the county, near Lough 
Sheelin. Formerly some quarries were open here, but now all 
stone is procured from the Ross Castle quarry, close by, in the 
Oo. Meath. Near Cavan some small quarries have been opened, 
but the stone is not generally valued for tool-work. 

Belturbet.—Light to dark-grey, fine, crystalline, but splintery ; 
thick and thin-bedded. Tools fairly. From this vicinity were 
procured the stones to build Crom Castle, on Lough Erne, Co. 
Fermanagh. 

Mount Nugent.—Quarries were formerly worked in this vicinity 
on a stone of good quality. They are now closed up, as all stones 
required can be more easily obtained from Ross Castle, Co. Meath. 

A fair, strong lime is made from the Cavan limestone. In the 
southern portions of the county most of the lime is procured from 
the neighbouring counties. 


CLARE. 

Throughout most of the barony of Burren and in the country 
near Ennis, there are large tracts of bare rock. The stone is of 
the Burren type, and is, in general, of excellent quality ; but some 
beds are much cut up by joints; others, however, are not, and 
from these stones of great dimension can be procured. As the 


Kinanan—On Irish Marbles and Limestones. 415 


limestone can be worked on the surface in so many places, very 
few quarries have been opened: the stones procured at some depth 
are, however, much more easily worked than those obtained at the 
surface. 

Rossievin. One mile from Ennis, where the stone is exten- 
sively used.—Dark-grey, semi-oolitic, crystalline, and close-grained. 
Works freely: but as the stones are of small dimensions they are 
procured at Bushy Park when required for larger size. 

Bushy Park. Over two miles from Hnnis.—Somewhat like the 
Rosslevin stone, but can be raised in much larger blocks. 

Kilfenora. Over six miles from Ennistymon, where the stone 
has been largely used.—Grey to dark-grey. Rather difficult to 
work. The great durability of the stone of this neighbourhood, 
and its capability of being used in fine work, is seen in the 
ancient crosses and the cut-stone work of the ecclesiastical ruins. 
Ancient work in Burren stone can also be seen in the ruins of 
Corcomroe Abbey, near Ballyvaughan. In connexion with the 
latter, the tradition in the country is, that the stones were procured 
in a cleft south-east of the summit of Moneen mountain, called 
“‘ Scalp-na-Shesbia,” but this seems to be a natural ravine, and due 
to weathering. 

In the south and south-east of the county quarries have been 
opened in various places for local purposes. South of Newmarket- 
on-Fergus there is a quarry in a red or reddish-grey stone, that 
was used in the building of Adare Manor, Co. Limerick ; it has 
also been worked for marble. 

The stones of this county make excellent and cheap lime. 
Along the south-west coast sea-shells used formerly to be burnt 
for lime. . 


Cork. 


In comparison with the extent of the county, there is not much 
Carboniferous limestone in it. It principally occurs in the valley 
of the Lee, near Cork, and thence eastwards to Youghal ; also in the 
valley of the Blackwater. Many of these stones are remarkable 
for their beauty. Macaulay has made the beautiful stone of which 
the Courthouse of Cork is built historical. 

Aherla. About nine miles north of Bandon.—Light-grey, 
platy, very easily worked ; can be sawn with advantage, and large 


416 Scientific Proceedings, Royal Dublin Society. 


flat stones can be procured. On account of the great ease with 
which this stone can be raised and worked, it is cheap, and has a 
considerable sale, even in Cork, nineteen miles distant. 

Ballintemple and Carrigmore.—Three miles from Cork. Light- 
grey, close, even-grained, and compact; works well and freely. 
This stone has been used extensively in the public buildings in 
Cork ; among others in the Courthouse, as mentioned by Macaulay. 
The capitals of the columns of the portico are well executed. 

Haulbowline.—Light-grey, not very easy to work; can be 
raised in large blocks. Used in building the new docks. 

Little Island.—Light-grey, close-grained, and compact; works 
freely. Was extensively used for the fortress at Spike Island. 

Carrickacrump and Ballyfin—Near Cloyne, and about twenty 
miles by water from Cork. The stone is carted to Aghada for ship- 
ment. Very similar in character, except as regards colour, to the 
Ballintemple stone, with which it does not contrast well. The Bank 
of Ireland in Cork was built of stone from this place. It can be 
raised in very large blocks, and can be more easily sawn and 
worked than any other limestone in the neighourhood of Cork 
Harbour. Ballyfin is about a mile from Carrickacrump, and the 
stone there has not been as largely worked. 

Fermoy.—Light bluish-grey, compact, but of variable texture. 

Ramaher (Kanturk).—Grey, compact, very fossiliferous; not 
easy to tool, on account of the fossils. 

Midieton.—Greyish-blue, inclined to reddish, compact, semi- 
erystalline, uneven in texture. Has been worked as a marble. 

Shanbally. Near Carrigaline.—Light-grey, of a flaggy nature ; 
an excellent stone for rubble work; not so good for dressed work. 

Fairlane. Near Mallow.—Light-grey, compact to splintery ; 
close-grained ; works fairly. 

Drishane. Two miles north-east of Millstreet.—Grey, compact, 
but in places having drusy cavities; works fairly well; quarried 
very largely for lime. 

Carraundulkeen. Three miles south of Kanturk.—Dark-grey, 
crystalline; semi-compact ; works well; very largely quarried for 
lime. 

In the limestone areas the lime, as a rule, is excellent and 
cheap. At Kinsale there is a bad lime brought into the town. 
In places along the coast sea-shells used formerly to be burnt. 


Kinanan—On Irish Marbles and Limestones. 417 


The dolomytes of this county have been utilized for the manu- 
facture of fluid magnesia. 


DongEGAL. 


The areas of Carboniferous rock are of very limited extent, the 
largest being that in which Donegal and Ballyshannon are 
situated. At Pettigoe there is a little strip outside the mearing of 
Fermanagh. ‘There are, however, in various places among the 
metamorphic rocks (Ordovician and Cambrian), beds and patches 
of the older limestone. Some of these are well suited for cut-stone 
work. The cut stone in the little church of Glenalla, near Rath- 
mullen, is from this class, and has a remarkably good appearance, 
and seems to be durable. The white and shaded whites, of which 
there are many varieties, are capable of being polished, and might 
be worked as marble; but almost invariably they are more or less 
coarsely crystalline ; or when fine-grained and compact, they are 
thin-bedded and full of joints, preventing their being raised, except 
in small pieces. These causes deteriorate their value, and prevent 
their being able to compete with the Italian stone. 

In the Metamorphic Rocks (Cambrian (?), Arenig, and Ordo- 
vician) limestones occur at the following places :— 

Ballymore. Four miles from Dunfanaghy.—Creamy white, in 
places clouded with brown, or having brown portions; highly 
crystalline; polishes well. Has been used as a marble. Difficult 
to work, but an excellent material for all cut-stone purposes. 

Marble Hill or Glaisheen. Two and a-half miles from Dun- 
fanaghy.—Pink and white, of a delicate colour, but with imbedded 
clouds of grey ; crystalline and slightly schistose. 

Rock Hill.—One and a-half miles from Dunfanaghy. Whitish- 
grey, slightly crystalline, in parts pyritous and micaceous, making 
the stone liable to discolour. 

Rinclevin.—Nearly a mile from Dunfanaghy. White, with 
greyish tint; highly crystalline; fracture smooth. 

Dunlewey. Six miles H.S.H. of Gweedore.— White and pink- 
tinted creamy white; blue, and green-tinted. At the western end 
of the seam there was a hard, white crystalline rock, very durable, 
as seen in the church close by, where it has not even lost colour. 
This stone was not followed in depth. The creamy and tinted 


varieties in the eastern portion of the quarry are in very thin beds, 
SCIEN. PROC. R.D.S.—VOL. V. PT. V. 2F 


418 Scientific Proceedings, Royal Dublin Soctety. 


and are so broken up by joints that they cannot be raised except 
in very small pieces. 

Lettevy. Over two miles from Glenties.—Light whitish-grey, 
silicious, and micaceous. In this vicinity are other quarries from 
which similar stones can be procured. 

Fintown. To the north of Lough Finn.—White to greyish 
crystalline. 

Glenveagh. A little south-east of the Castle-—White: highly 
crystalline. Only the surface of this bed has been opened. Here 
it is friable and much cut up by joints. Stone untried in depth. 

Lough Akibbon (Garton). Over two miles north of Church Hill. 
— White and pinkish, solid, fine, crystalline; polishes well; seems 
capable of being raised in large blocks. Appears to be an excellent 
material for all cut-stone purposes; but as yet the quarry has only 
been very partially tried. 

Drumlakagh. Nearly three miles eastward of Creeslough.— 
White and grey-tinted ; crystalline ; thick and thin-bedded. Could 
be raised in fair-sized blocks. Not at present worked, except for 
lime. 

Ardanawark. 'Two miles north-east of Lough Salt, in the hills 
north-east of Kilmacrennan.—White and pinkish, highly and 
coarsely crystalline. Can be raised in large blocks. Appears to 
be well suited for tool-work, but at present only worked for lime. 
Polishes well and easily. 

Magheraboy. Three miles south-east of Letterkenny.— White 
to pinkish; very crystalline. This stone seems to be totally 
unworked, although, from its appearance, it ought to give good 
lime, and be suitable for cut-stone purposes. As it is near 
Letterkenny, in which neighbourhood there is no stone of any 
kind suitable for tool-work, this seems worthy of a trial. 

Cloghroe. Two and a-half miles from Stranorlar.—Bluish-grey 
and white; crystalline; partly schistose. 

Cullanacon. 'Two miles west of Convoy.—Greyish-white and 
pink-shaded ; crystalline ; thin-bedded, with schistose partings. 

Kiltole. Nearly a mile east of Convoy.—White to pinkish ; 
compact; crystalline. A good stone, but thin-bedded. 

Maghera-sollus. A mile E.N.E. of Raphoe.—White and 
greyish-white ; compact; crystalline; thin-bedded, with schistose 
partings. 


KinaHan—On Trish Marbles and Limestones. 419 


Crauford. Four miles northward of Milford, on Mulroy Bay. 
—lLight to dark bluish-grey; compact to shattery; crystalline ; 
in part schistose; makes excellent lime. 

Kindrumlough. A little west of Kindrum Lodge, in Fanad- 
within-the- Waters.— White to creamy white; coarsely crystalline 
to compact; shattery, but seems to be suited for tool-work. As 
yet untried. Surface-pieces polished well, but were shattery and 
facial. 

Tamney. West of Croaghan House.—A dolomyte of a Sienna 
character. Untried, but appears too gritty and irregular to be of 
much value. 

Kintale—A mile and a-half northward of Rathmullen, on 
Lough Swilly. Bluish-grey, in part earthy and in part micaceous. 
Works easily ; can be raised in large blocks. One black bed has 
been locally used as a marble. 

Hill Head. Four miles from Carndonald.—Dark blue to grey ; 
finely crystalline. ‘This stone has its peculiarities ; because when 
first raised, it is soft and crumbly, but afterwards it hardens into a 
good stone. 

Various other detached masses occur also in different places in 
the hills, but it is unnecessary to enumerate them. 

Good or fair stone in ‘the Carboniferous is recorded as fol- 
lows :— 

Baillyshannon.—Brownish-grey to dark greyish-blue ; earthy; 
compact ; semi-crystalline ; works freely. 

Donegal.—Greyish-black ; very earthy, the calcareous matter 
being very small. Not much used. 

The Carboniferous limestones near Donegal and Ballyshannon 
burn into a good lime. The older limestones Ordovician and Cam- 
brian, are very generally used, the lime being nearly invariably dark- 
coloured, but strong. Some of the white varieties, however, give a 
white lime. A peculiarity of some of these limestones is, that when 
they are used as road-metal, the road becomes plastic in continuous 
wet weather, becoming again quite hard when it is warm and dry. 


Down. 


This is one of the Irish counties in which there is scarcely any 
Carboniferous limestone. It occurs only in a small tract at Castle 


Espie, two miles south-east of Comber, and in the extreme south 
2F 2 


420 Scientific Proceedings, Royal Dublin Society. 


end of the county at the entrance to Carlingford Lough. The 
stone at Castle Espie is worked solely for lime. 

At Cultra, on Belfast Lough, a little Carboniferous limestone, 
associated with Permian dolomyte, occurs below high water-mark. 

Cretaceous, or the White Limestone, occurs in the west of the 
county, in the north-west slope of the valley of the Lagan. It is 
worked largely for lime in the neighbourhoods of Moira and Lur- 
gan. It is too brittle and jointed to be finely tooled or procured 
in large blocks, but it can be squared by scabbling into blocks 
suitable for rough masonry. 

Lime in this county is scarce, most of it being imported. It is. 
procured from the Carboniferous limestone at Castle Espie,and from 
the White Limestones of the Lagan Valley. In places on the coast 
sea-shells were formerly burned into lime. 

The Permian dolomyte of Cultra, on Belfast Lough, was formerly 
utilized by being exported to Glasgow for the manufacture of sul- 
phate of magnesia. 


DuBLIN. 


Nearly all the limestone in this county is more or less of the: 
Calp type, and varies greatly in character. In general it is only 
suitable for rubble-work ; but as it can be raised in large sizes it is. 
valuable for foundations. Some beds make good lime, while ad- 
joining beds may not burn at all. 

The best stones occur near Lucan and Leixlip, near the mearing: 
of the Co. Kildare, from whence they were procured for the Cus- 
tom House Docks. Calp limestone was also used in the building of 
the old church in Mountjoy-street and the old Christ Church Cathe- 
dral, while the latter was repaired by Calp brought from Rathgar 
and Kimmage. For many of the old buildings the stones were so 
badly selected, that they are now weathered into rotten shaly or 
earthy masses. 

In the north part of the county there are stones of a coarsely- 
crystalline character, not well suited for tool-work, but capable of 
being raised in very large blocks. 

Milverton.—This and other quarries occur in the neighbourhood ~ 
of Skerries. Grey, coarsely crystalline, compact, and even-bedded.. 
Rather hard to tool, and not well suited for fine work ; but, on ac- 
count of its strength and the possibility of procuring it in large. 


Kinanan—On Irish Marbles and Limestones. 421 


biocks, itis suitable for massive work. From this were obtained the 
large cap-stones for the pillars of the Boyne Viaduct. They were 
also extensively used in the construction of the Lighthouse on 


— Rockabill. 


Donnybrook and Miltown.—Here formerly were extensive quar- 
ries, principally in the river and to the eastward of it, but now 
they are very little worked. Dark-grey to blackish, earthy ; 
suited for foundations and rubble-work, but not for cut-stone. It 
was, in a great measure, the use of the Donnybrook Calp in 
repairing the streets that got for Dublin the soubriquet of “ dear, 
dirty Dublin.” 

Rathgar.—From pale to dark-grey and blackish; from thick- 
bedded to good flags. This quarry was once extensively worked. 
The ordinary stones were good for rubble-work, and the flags of a 
very fair quality. The best beds, being nearly equal to the 
““ Carlow flags,” were extensively used. 

Kimmaae and Crumlin.—The stones in these quarries are more 
or less similar to those at Donnybrook, Miltown, and Rathgar. 
These supply to a great extent the rough and foundation stones 
now required in Dublin. 

Ballymacauly and Collierstown.—On the Royal Canal, between 
Leixlip and Lucan. From these quarries were taken the stones to 
build the Dublin Custom-house docks. Formerly very exten- 
sively quarried. 

Lime from the Calp is, in general, dark-coloured and inferior, 
some beds being, however, very good. A great deal of the lime- 
stone used in Dublin for lime is brought from the neighbourhood of 
Slane, Co. Kildare. 

At the present time the limestone which appears to be most 
approved of by the Dublin builders is the Ballinasloe, Co. Galway, 
stone, which can be seen in the Hibernian and Munster (Head- 
office) Banks; next to it the Tullamore, King’s County, the latter 
being much in request for monumental purposes, and was used in 
the monument at Glasnevin to the late Under-Secretary, Mr. 
Burke. The Ardbraccan stone, Co. Meath, although it has a 
good appearance when finished, is soft, and does not keep its 
colour; and with it is classed the Ross Castle stone, Co. Meath ; 
but the stone from the neighbouring quarry at Crossagh, although 
coarser, is more favourably thought of. The Milverton stone, near 


422 Scientific Proceedings, Royal Dublin Society. 


Skerries, works easily, but is full of verts and defects. The Sheep- 
house stone, near Drogheda, was used in the restoration of Christ 
Church Cathedral, although it has the reputation of being of a 
soft, poorish class. 


FERMANAGH. 


In the centre of the county, forming the valley of the river 
and the two loughs Erne, there is a considerable tract of Carbo- 
niferous limestone; but in some places the stone is of a bad 
quality, not being even fit for lime-burning. Where good stone 
does occur, it is not as much sought after as in other counties, the 
sandstone being of good quality, and very generally used for 
dressed work. In the erection of Crom Castle, the seat of the 
Earls of Erne, limestone from Belturbet, Co. Cavan, was used ;. 
but the quoins and dressings are of sandstone. Most of the public 
buildings in Enniskillen, as also in the other towns, are built of 
limestone. 

Kinarla. About a mile and a-half by water from Enniskillen. 
—Dark-grey; not a sound stone; was used in building the church 
and part of the Roman Catholic church in Enniskillen; also by 
the Ordnance Department. 

Derrygon. Half a mile from Enniskillen, on the lake shore. — 
Dark-grey, compact, good quality ; used in the gaol and the new 
bridge built by the Drainage Board. 

Mullaghree. Two miles from Enniskillen.—Light-grey, sound, 
tough, flat-bedded. 

Carrickreagh. Five miles by water from Enniskillen.—Dark- 
grey to black, of excellent quality; polishes well; has been used 
extensively in Enniskillen; lately in the new cemetery church, 
and as quoins and dressings in the Roman Catholic church; also 
used for tombstones. | 

Kesh. One mile from the town.—Dark-grey, fairly compact, 
even-bedded, with shale partings; used in the railway bridges and 
in the buildings of the neighbourhood. 

Eiderny.—Similar stone to that at Kesh; Market-house built 
of it. 

Belleek.—At the Falls. Dark-grey, crystalline, compact, and 
close-grained; used in building Belleek Works. 

Lisnaskea.—Dark-grey, good, sound, well-bedded stone, but 


Kinanan—On Irish Marbles and Limestones. 493. 


difficult to work with tools, owing to layers of chert in it. The 
Market-house and Railway Station are built of it. 

Newtownbutler.—Bluish-grey, semi-crystalline, compact, earthy ; 
Market-house built of it. 

During the recent works for the drainage of Lough Erne they 
excavated into a dark compact limestone at Belleek Ford, which 
was used in the works thereabouts ; while the new west bridge of 
Enniskillen is built of the stone quarried while cutting away the 
Portora Ford. 

Some of the limestones are too earthy to burn into lime, but 
good strong lime is plentiful and cheap in the county, the best 
stones being procured westward of the lakes. A stone at Castle 
Caldwell gives a hydraulic lime. 


GALWAY. 


This county produces excellent limestones, suited for all cut- 
stone purposes, as they belong both to the older formations and 
to the Carboniferous. In the older formations (Ordovician and 
Cambrian), there are stones suitable both for tool-work and marble, 
in shades both of white and green. Those of green colours are 
unsurpassed elsewhere as marbles; but the whites, on account of 
their coarseness or other peculiarities, have not a forward place in 
the market. All these stones except the greens are more or less 
burnt for lime, some being better than others. 

At Salrock, Derreennasliggaun, and Leenaun, in the north 
part of the county, there are Si/wrian limestones. Some of those 
at Derreennasliggaun are reddish, and have been used as a marble. 

The Carboniferous limestones occupy all the eastern portion of 
the county, being nearly altogether either of the Calp or Burren 
types, principally the latter. Those of the Burren type are most 
conspicuous in the long tract that to the north enters the county 
from Mayo at Lough Mask, and extend southwards to Galway, 
and from that to the barony of Burren, Co. Clare. In these crags, 
in numerous places, superior rocks can be obtained; and the sur- 
face rocks in many places are worked; but necessarily they are not 
as easily tooled as in places where a quarry has been opened. They 
are of different shades of grey and blue, with subordinate black 
leds. From the latter some of the best black marbles in the 
world have been obtained. 


424 Scientific Proceedings, Royal Dublin Society. 


The limestones of this portion of Galway, as also of the 
adjoining parts of Mayo and Clare, are so eminently suited for all 
cut-stone purposes, that now, as in former years, they are used to 
the exclusion of all other stones, although in the neighbourhood 
of the town the granites are unsurpassed in beauty, variety, and 
quality. 

The great durability of the Galway limestone, and the delicate 
workmanship of which they are capable, are displayed in the 
various old ecclesiastical structur es about the country, and also in 
the eleventh-century buildings in f the town of Galway ; which are 
still very perfect, notwithstanding the rough usage to which they 
have been subjected. Some of the pillars and other fine work in 
the Abbey of Knockmoyne, Ballyglunin, are still most beautiful. 

The best stones of Ordovician and Cambrian ages are recorded 
at the following localities :— 

Streamstown. About two miles north of Clifden. —Variegated 
and streaked green; worked for marble. 

Creggs. About four miles east of Streamstown.—White to 
creamy white; and coarsely crystalline to compact and fine- 
grained; eminently suited for delicate cut-stone purposes, but 
cannot be procured in very large blocks; has been worked for 
marbles. 

Clifden. In the vicinity are limestones.—Bluish-grey or dove- 
ecloured ; more or less schistose; and difficult to work. 

Barnaoran.—The “ Ballynahinch marble quarries,” in the valley 
of the Owenmore. Green and variegated; worked for marble. 
The colours of the stone are very delicate and fugitive, which 
makes it unsuitable for any outside work. 

Derryclare. Adjoining the lake.—White, or with a greyish 
tint; crystalline ; compact ; easily worked; but rises in unshapely 
blocks, which causes a waste in dressing. Was quarried some 
years ago by the Martins of Ballynahinch. 

Lisoughter. Near the village, one mile from Recess. aGeraanl 
and variegated ; solely worked for marble. 

Other stones of shades of green and white are already described 
in the lists of Galway marbles. 

Of the innumerable Carboniferous limestone localities, the 
following may be specially mentioned :— : 

Galway.—To the north-east of the town, between it and Men- 


Kinanan—On Irish Marbles and Limestones. 425 


lough, are extensive crags. The portion at the surface has been 
worked in different places, wherever the stone took the fancy of 
the stonecutter. A few quarries have been opened. Whitish to 
grey and blue, with subordinate black beds; crystalline; compact ; 
fine-grained. Suitable for all kinds of cut-stone work ; while the 
black beds are superior marble. It would appear as if a remune- 
rative trade in their stone to England and elsewhere might be deve- 
loped, as the limestone is of such excellent quality, while the freight 
ought to be low on account of so many ships, trading to the west 
coast, having to return in ballast. 

Angliham and Menlough. About three miles north of Galway .— 
Worked for the marble beds. 

Two-mile Ditch. Two miles from Galway.—Bluish-grey ; crys- 
talline; uneven-grained ; easily worked. 

Gortveragh. About one mile H.S. E. of Oughterard.—Dark- — 
grey to black. Formerly worked by the Martins of Ballynahinch 
for marble. In this vicinity, and north-westward to Oughterard, 
there are good stones in various places suited for tool-work. A 
quarry was formerly worked in Creggs, from which good black 
stones were procured, one forming the flag at the hall-door of 
Lemonfield House, the seat of the O’ Flaherties. 

Arran Islands.—Great sheets of limestone of different shades of 
grey and blue; superior stone. On the north island, or Arran- 
more, some of the beds are of considerable thickness, and without 
joints for lengths of 150 feet to 200 feet or more, out of which 
great monoliths might be procured. 

Newtown. Two miles from Gort.—Bluish-grey ; close-grained ; 
fossiliferous ; works freely. 

Ballyleigh, near Gort.—A fine black stone, formerly worked as 
a marble. 

Castleboy. Between Gort and Loughrea.—Bluish-grey to grey ; 
not difficult to work. 

Craughwell. Seven miles from Loughrea.—Bluish-grey ; an 
easily-worked stone. 

Brackernagh, Ballinasloe.—Light to dark-grey ; close- grained, 
crystalline ; hard ; an excellent stone ; polishes well; can be raised 
in large blocks; wrens as a deislee used very extensively in 
Dublin for all kinds of cut-stone purposes; carriage, in waggon 
loads, about 7s. 6d. per ton. 


426 Scientific Proceedings, Royal Dublin Society. 


Workhouse (Ballinasloe).—Shght bluish-grey, crystalline, com- 
pact, hard; a good stone; difficult to work. 

Kilroe.—Nine miles from Tuam. Bluish-grey; close-grained, 
semi-crystalline ; splintering in fracture; works well. From here 
were procured the blocks for the cut stone for the R. C. Cathedral 
of Tuam. 

Workhouse (‘Tuam).—Bluish-grey, crystalline, uneven-grained : 
smooth fracture. 

Cong.—In the vicinity of Cong, in the counties Galway and 
Mayo, there are extensive crags of excellent stone, capable of being 
procured of any size, and the stones of some beds taking a good 
polish. It is suitable for all cut-stone purposes. The cut-stone: 
work in the ancient abbey at Cong attests its durability, and the 
fine class of work it can be applied to. Some of these stones are 
capable of being split into long beam-like masses, suitable for 
bridges, for which purposes they have been used. 

The Carboniferous limestone gives an excellent lime. The Silu- 
rian limestones at Salrock, Derrynasliggaun, and Leenaun, do not 
appear to have been much used, while the metamorphic limestones 
give a strong dark-coloured lime, but a small return. For this 
reason, in the west and north-west of the country Carboniferous. » 
limestone is generally procured either from the Arran Islands or 
from Clew Bay, Co. Mayo. In old times sea-shells were burned for 
lime along the Connemara coast. 


Kerry. 


The Carboniferous limestone occupies a considerable area in the: 
eastern portion of the county, including a small isolated tract near 
Kenmare. It is of various characters, being cleaved or slaty near: 
Kenmare, while to the north it partakes of the characteristic both of 
the Calp and Lower limestone, except at the Lakes of Killarney,. 
where, in general, it is more or less slaty like that of Kenmare. 
This slaty stone was used in the building of the Abbey of Muck- 
ross, and furnished some very well-finished work. Limestone of 
Ordovician age occurs on Caherconree in the Dingle promontory. 

In the Carboniferous the stones best known are as follows :— 

Kenmare.—Grey and blue; slaty ; difficult to work across the beds; 
can be made into good jambs, window-sills, and such-like, espe-- 
cially if sawn across the grain. 


Kinanan—On Irish Marbles and Limestones. 427 


Lisaviggeen and Cahirnagher. About three miles from Killarney. 
—Grey, crystalline, even-grained, hard, but works well. Thesv- 
quarries chiefly supply Killarney with all cut and rubble stone. 

Listowel.—Dark-grey, compact, earthy; works freely. This 
quarry has been largely worked for years, supplying stone to all the 
neighbourhood. The upper beds are a bad-class stone, but the lower 
are fit for any purpose, and with care can be raised of large sizes. 

Ballinageragh.—S8ix miles west of Listowel. Dark-grey to black. 
Good for all cut-stone purposes. One bed black, mottled with white,. 
was formerly worked for marble. 

Rathos (‘Tralee).—A coarse, cherty stone, but useful for rough 
squared work. 

Ballymacelligot.—About six miles from Tralee. Bluish-grey,. 
close-grained ; partly earthy; free-working; has been very exten- 
sively used in Tralee in the public and private buildings. 

Good and cheap lime is made from the Carboniferous limestone. 
The Ordovician limestones of Caherconree, Dingle promontory, are 
also used for lime. 


KOLDARE. 


Although most of this county is situated in the great Carbo- 
niferous tract of the central plain, none of the limestones that have 
been quarried are particularly well suited for cut-stone purposes,. 
the best stones being procured near Celbridge and Leixlip, ad- 
joining the Co. Dublin—stones that have been already described. 
Here, as elsewhere, all the quarries that have been opened are in 
stones of the Calp type, except those near Slade and Sallins, which, 
however, have been almost entirely worked for the purpose of 
being sent to the Dublin market for burning into lime. . 

Lime is very plentiful and good, the Calpy stone being in 
general burnt, or else boulders got in the Drift. At the Chair of 
Kildare there are Ordovician limestones, which are also burnt ; 
but the lime from the Carboniferous limestone is preferred. 


KILKENNY. 


In Kilkenny there is a considerable area of Carboniferous. 
limestone, the rock in many places being of a class fitted for all 
cut-stone purposes. The ordinary stone is usually in shades of 
dark-grey and blue, varying from close-grained to open-grained, 


428 Scientific Proceedings, Royal Dublin Society. 


very tough, but working freely. It is very durable and strong, as 
exemplified in the different ancient buildings, as well as in the 
more modern structures. Almost everywhere it can be procured 
in whatever sizes may be required. Wyley has pointed out that, 
in Jerpoint Abbey and elsewhere, where a slight pillar had to 
support a great weight, limestone was used in place of sandstone. 
Associated with the ordinary limestone are creamy dolomytes. 
These have been, in general, ignored by the modern builders, but 
some of them, at least, are good and durable stones. In the base, 
and notably in the jambs, of the doorway of the Round Tower of 
St. Canice, Kilkenny (9th century), this stone was used, inter- 
mingled with sandstone. They have stood well; and, although 
showing the cavities so common in these stones, have not weathered. 
Most of a large flour-mill at Rockview, Inisnag, is built of this 
creamy dolomyte, from a quarry on the opposite side of the 
King’s River. 

Callan, Urlingford, Gowran, and Thomastown.—Quarries in the 
vicinity or neighbourhood of these different towns. Grey and 
blue limestones, suitable for all sort of cut-stone purposes. 

Bonnetrath, Black Quarry, St. Kyran’s, Templemartin, Archer's 
Grove, Sion House.—These quarries are all in the neighbourhood 
of Kilkenny, and give stones more or less favourable for cut-stone 
purposes. ‘The Black Quarry and that at Sion House (now filled 
in) were quarried principally for the marble beds (see Marbies). 

Ballykilaboy, Ballykeaghan, and Granny.—These quarries are 
situated in the south of the county, near Kilmacow and the River 
Suir; they are principally worked to supply stones to the counties 
Waterford and Wexford. Grey, crystalline, fine to coarse-grained ; 
easily worked ; take a good polish. The best stone can be pro- 
cured at the first and second localities, and of large sizes—I17 feet 
by 4 and 6 wide, and 2 feet thick. They have been extensively 
used in Waterford, as has also been the Granny stone, which, as it 
is situated on the bank of the Suir, and can be cheaply brought to 
Waterford by water, is utilized, notwithstanding its being of a 
flaggy nature and friable. 

The lime made in this county is, in general, very good. 


KinaHan—On Irish Marbles and Limestones. 423> 


Kine’s County. 


Except in Slieve Bloom and in Croghan Hill, the rocks of this- 
county are limestones, some being of excellent quality and well 
known. - 

Banagher.—In this vicinity the rocks are of the Calp type. 
Dark-blue or grey, inclined to black, earthy, in part flagey, and 
difficult to dress; can be raised in large blocks suitable for coarse 
work, and were used extensively in the works for the improvement 
of the Shannon navigation ; also in the buildings in the town and 
neighbourhood. 

Skerough.—A mile from Birr or Parsonstown. Grey; compact,. 
semi-crystalline; uniform in colour; easily worked ; has been used 
very much in the public buildings of Parsonstown. 

Clonmacnoise (Seven Churches).— Grey; thin-bedded ; some- 
beds very fossiliferous ; weathers unevenly. Stones of large size, but 
modern thickness, can be obtained. This stone was very much 
used in the old buildings at Clonmacnoise, and in the works on the- 
Shannon. The fossiliferous beds full of encrinite stems (locally 
called ‘‘screws”’) when polished have a quaint appearance, and have 
been much used for chimney-pieces, &c., having been formerly 
very extensively wrought at the Killaloe marble works. Wilkin- 
son remarks, in connexion with the ruins at Clonmacnoise :—“ In 
the doorway of one of these churches this stone has been used for 
delicate carving, and the surface of the door-jambs is polished, 
doubtless to display what was considered a beautiful material.” 

Upper Eglish.—Eighteen miles from Parsonstown. Grey, com- 
pact, easily worked. A great deal is sent to Parsonstown, being 
cheaper than the stone in that neighbourhood. 

Killane.—Near Edenderry. Grey, compact, easy to work. 

Bailydule (‘Tullamore).—Grey, with purplish tinge, crystalline, . 
massive, thick-bedded, and can be obtained in large blocks. It 
takes a fine polish, and is then of a dove-colour, clouded with a 
darker tint. It is very much admired in chimney-pieces and or- 
namental slabs. This well-known and beautiful stone has been 
used in the tracery, windows, and dressing, in St. Patrick’s Ca- 
thedral, Dublin; for columns and cornices of the Club-house, 
Kauldare-street ; the Roman Catholic Church, Monasterevan ; and. 
in numerous other places. Formerly more used in Dublin than. 


430 Scientific Proceedings, Royal Dublin Society. 


at present, the Ballinasloe stone having, in a great measure, taken 
its place. This seems to be due to the cheaper carriage of the 
latter stone. 

Lime, in general, is very good and cheap in the King’s County. 


Le&ITRIM. 


Although a large portion of this area is limestone, yet this 
being, in general, of a calpy character, the best cut-stones are 
usually brought from the neighbouring counties. The caps on 
the gate-posts of the King’s Demesne, near Drumsna, came from 
Ballinrobe, in the Co. Mayo. In the north portion of the county 
there are in some places very good stones, but no quarry of more 
than local note seems to be worked. 

Mealwood.—Three miles and a-half from Carrick-on-Shannon. 
‘Greyish-blue; crystalline; compact; splintry; difficult to work: 
large blocks can be procured. Formerly this stone was much 
used, but of late better stone is brought from Hughes’ Wood, in 
the Co. Roscommon. 

Castleslavin. Three miles from Carrick-on-Shannon.— Whitish- 
grey, crystalline ; fairly easy to work ; retains its colour. 

Ballinamoe.—The stone here similar to that at Mealwood. 

Kilbride.—One mile from Drumsna. Bluish-grey; not very 
good for tool-work. 

Lime in this county good; of superior quality near Manor- 
hamilton. 


LIMERICK. 


More than half of this county is occupied by limestones of dif- 
ferent qualities, the rocks being more distinctly and regularly 
grouped than elsewhere in Ireland, as previously pointed out 
(page 375). Margining the exposure of sandstone is the dark- 
blue, coarse, grey bedded Lower limestone, having over it the 
unbedded Fenestella limestone, and above that the Calp, ranging 
from a coarse slate and shale to marble; and above all, under the 
Coal-measure shales, the Burren-type rock. 

Oorgrig. A. little S.S.H. of Foynes.—Dark-blue and grey, 
crystalline; in part earthy; works fairly well; flat-bedded; ca- 
pable of being raised in very large blocks. Used extensively in — 
pier-work on the Shannon, both in Clare and Limerick. 


Kinanan—On Irish Marbles and Limestones. 431 


Askeaton.—The Fenestella limestones of this neighbourhood 
were used extensively in the old castle of the Geraldines, and in 
Askeaton Abbey. The beauty of the stone, its qualifications for 
eut-stone purposes, and its durability, are displayed in the orna- 
mentation of the banqueting-hall of the castle and the windows of 
the abbey, but especially in the pillars of the cloisters. The latter 
are beautiful examples of carving, while at the same time they 
exemplify the fact that this stone is capable of taking a good and 
lasting polish. The exact place where these stones were quarried 
is not known; they are speckled greys, with tints of pink and 
dove-colour. 

Kylethane (near Kathkeale).— Dark calpstone, inclined to 
blackish ; in part shaley; hard, but works evenly except across 
the grain. 

Churchtown (Newcastle West).—Dark grey. Works freely, 
but is very wasteful. 

Drumroe.—Seven miles from Newcastle. A somewhat similar 
stone, but better than that at Churchtown, and generally preferred 
to it, butit is very brittle. 

Ballycummin —About three miles from Tene Bluish-grey ; 
works well. 

Rosbrien.—Near Limerick. Very similar tolast; a good stone. 

Limerick.—Thomond Gate.—Greyish-black; fine, and close- 
grained; some of the beds formerly worked for marble of a 
superior quality. Bridge quarry.—Grey ; compact; a good sound 
stone. Carey’s-road.— Dark grey; semi-compact. Gillogue.— 
Blackish ; very close-grained; good hydraulic lime. Railway 
Quarry.—Grey, black, and green. The black stone was worked for 
marble many years ago, and was good, being sent to the London 
market; the green is tuffose and arenaceous; works easily; 
friable; not durable; used extensively in the new railway station. 
The grey stones and those in the other quarries work more or less 
freely and well. They have been extensively used in Limerick 
and the neighbourhood. 

Charleville.—Dark-grey; crystalline; compact; a free-working 
stone. 

Quarry Hill, Knockany.—¥ our miles from iKeilenaliloe es Greyish- 
blue; close-grained; very easy to work. It would appear from 
the nature of the stone that it was from these quarries that 


432 Scientific Proceedings, Royal Dublin Society. 


the stones were procured to build the Abbey, and the Geraldine 
town of Kilmallock. In the latter, a few years ago, there were 
excellent examples of this ancient cut-stone work; but during 
the last twenty-five years nearly all these old structures have been 
removed. 

The lime in this county, in general, is good; but that made 
from the Churchtown stone (Newcastle West) is poor in strength, 
and slacks slowly : the lime made from the Calp, near Rathkeale 
and Adair, is also poor. 

At Robertstown, between Barrigone and Foynes, there is a 
stone that gives a good hydraulic lime, which was used at Askea- 
ton Mills. In Gilloge Loch quarry, two and a-half miles north- 
east of Limerick, there is a good hydraulic limestone, which was 
used extensively during the building of the new dock at Limerick. 


LonDONDERRY. 


This county is another of those in which there is very little 
Carboniferous limestone; it only being found in a tract between 
Maghera and Magherafelt. It is principally quarried for lime- 
burning, some of it being hydraulic. 

Along the margin of the doloryte plateau, White Limestone 
appears in places, and is rather largely quarried, but principally 
for lime-burning, as its brittleness and jointy character make it 
yield unequally to the hammer, and unfit for fine tool-work. It 
can, however, be scabbled into blocks of small dimensions, which 
can be used in rough masonry. 

In the hill-country, especially south and south-west of Dun- 
given, there are many beds of metamorphic limestone (Ordovician ?) 
quarried principally for lime-burning. 

The principal quarry in the Cretaceous rocks is at— 

Spring Hill (Moneymore).—White; very pure; hard; fissured 
and cracked. Cannot be raised in large sound blocks. Can be 
scabbled into blocks of small size. Extensively used in Moneymore 
when building the princfpal houses. 

The quarries in the Carboniferous limestone are as follows :— 

Desert Martin.—Bluish and. brownish; rubbly; some beds 
yellowish-grey ;- solid; finely granular; crystalline, magnesian, 
and hydraulic. Used almost entirely for lime-burning. 


Kinanan—On Irish Marbles and Limestones. 433 


Drumbally.—Very similar to the limestone at Desertmartin, 
and, as there, the yellowish rocks are hydraulic. 

The limestones from the metamorphic rocks in the Tirkeeran 
Hills (south and south-west of Dungiven) give a good, strong, dark- 
coloured lime; while those of Carboniferous and Cretaceous age 
give purer and clearer products, and also yield a larger return. 

At Desert Martin and Drumbally there are good hydraulic 
limestones, which were extensively used during the building of the 
bridges over the Bann, at Coleraine, Portglenone, and Toome. 


LoneForp. 

Except to the northward, where the older rocks are exposed, 
this county is principally Carboniferous rocks. They, however, 
are nearly invariably more or less obscured by surface accumula- 
tions, such as drift and bog. 

Lisryan. Four miles from Granard.—Dark-grey, earthy, com- 
pact ; pyritous in places; principally in layers; partly shaly. 

Crossrea. Near Granard.—Dark-grey; spotted when polished; 
coarse ; in part fossiliferous. 

Crewes. Three miles from Longford.—Light-grey. In the 
upper portion the beds are from 23 inches to 3 feet thick, but the 
lowest bed is over 18 feet thick. From the 23-inch bed flags 
30 feet square or more could be procured. From the bottom, 
blocks 10 feet long and 6 feet wide can be raised. The stone is 
very highly thought of, and was used in the building of Carrick- 
glass House. 

Richmond Harbour. Five miles from Longford.—Greyish- 
blue ; can be raised in very large blocks. Used extensively in the 
Shannon works at ‘Tarmonbarry. . 

Ratheline. Near Lanesborough.—Dark-grey ; compact; works 
freely and polishes well. It was used largely in the works on the 
Shannon in the vicinity of Lanesborough. 

The lime of this county is generally good. 


Lovutu. 

A very small extent of Carboniferous limestone is found. It 
eccurs in the valley of the Boyne, at Ardee, north and north-east 
of Dundalk, and near Carlingford. 

Greenore and Carlingford.—Bluish-grey. eset sive quarried 


SCIEN. PROC. R.D.S.—VOL. VY. PT. V. 2G 


/ 


434 Scientific Proceedings, Royal Dublin Society. 


to supply the south portion of the Co. Down and Dundalk with 
lime and cut stone. In some beds very large blocks can be raised ; 
principally quarried for lime; not very good for tool-work. 

Kileurly. ‘Two miles from Dundalk.—Greyish-blue; compact ; 
crystalline ; works freely. 

Ardee.—Dark-grey ; semi-compact; difficult to work. 

Drogheda.—Dark greyish-blue, inclined to black ; earthy ; com- 
pact; in part shaly. The old buildings in which it has been used 
are very much weathered. 

Sheephill. Three miles from Drogheda.—Light bluish-grey ; 
crystalline; compact; works freely. A very good stone, very 
unlike any other in the county, being more like those at Lough 
Sheelin, in the Co. Meath (Ross Castle). It has been used in 
some of the public buildings in Drogheda, and extensively in the 
adjoining portion of the Co. Meath, and in the restoration by 
Mr. Roe of Christ Church Cathedral, Dublin. 

Lime strong and good, but dark-coloured. 


Mayo. 


As in the adjoining county of Galway, there are here also 
extensive crags or sheets of bare limestone, especially in the neigh- 
bourhood of Lough Mask; and the good quality of the limestone 
has prevented other stone being wrought or even looked for. 

Cong and Ballinrobe.—In various places in the neighbourhood 
of these towns, varieties of grey and blue; crystalline; compact ; 
sound; works easily; splits easily; can be raised in very large 
blocks ; suitable for all kinds of cut-stone purposes. 

Westport.—Two quarries in the vicinity, the larger called 
Farm Quarry. Greyish-blue; very good quality; bedded from 14 to 
2 feet thick. At the Farm Quarry there is a clearing of about 
20 feet of soil and 16 feet of bluish sandstone. A peculiarity of 
the limestone is the occurrence of invisible joints, called ‘ threads”’ 
by the quarrymen. These do not detract from the value of the 
stone, as it does not weather, nor, when in work, do the stones 
crack along them. They are of great use to the workmen, as 
by experience they have learned that, if they throw water on 
the face of a bed, they can see the “threads” when it is drying 
off, and subsequently, by the judicious application of the wedge, 
they can readily split the stones. 


Kirnanan-—On Trish Marbles and Limestones. 435 


Wakefield, or Black Quarry (Castlebar).—Dark-erey or blackish, 
of the Calp type; very coarse; can be scabbled, but not fine- 
worked ; very large blocks can be raised. 

Moneen. One mile from Castlebar.—Bluish-grey; fairly easy 
to work ; was used when building the gaol and infantry barracks. 

Crossmolina.—Dark-grey to blackish ; compact; dense; earthy. 
It is quarried near Rosserk Abbey, which was partly built of it. 
Wilkinson points out that it is not a stone to be recommended, as 
it is brittle, and liable to break off when in work, which, he points ~ 
out, can be seen in the windows and doorways of the Fitzgibbons’ 
Castle, a few miles north of Castlebar, where a similar stone was 
used. 
Ballina.—In this neighbourhood the stone is very similar to 
that of Crossmolina. 

Moyne. Seven miles from Ballina.—Dull-grey; has an irre- 
gular fracture, but can be worked in any direction, and can be 
procured in very large blocks. A superior stone for any cut-stone 
purposes. It occupies a considerable area between Rosserk and 
Killala, the latter town being built on it; it also occurs at Moyne 
Abbey. The durability of the stone and its excellent qualities are 
exhibited in the Round Tower of Killala, the Abbey of Moyne, 
and the cut-stone in Rosserk Abbey. This stone was also used in 
the mansion of the Knox-Gores, near Ballina, and for cut-stone in 
the Roman Catholic cathedral. 

Excellent lime is made from the Carboniferous limestone ; also 
from boulders in the Drift. A Silurian limestone near Toorma- 
keady is said to be hydraulic. Near Cong there is a clay which, 
if mixed with lime, makes it hydraulic; used extensively at Cong 
in the river works, and at Lord Ardilaun’s fountain. 


Meratu. 


Carboniferous limestone occupies the principal part of the 
county, but it is divided into north and south districts by a tract of 
arenaceous and slate rocks. The stones in the southern district 
partake very much of the Calpy nature of the rocks in the Co. 
Dublin, while very superior stones are procured in the northern 
division, the quarries of Ardbreccan and Rosscastle, or Cashel, being 


extensively known ; also the neighbouring quay of Crossagh. 
262 


436 Scientific Proceedings, Royal Dublin Society. 


Ardbreccan. Three miles from Navan.—Brownish-grey ; when 
dressed, grey, very crystalline; works very freely ; can be obtained of 
very large sizes; a very superlor working-stone. Has been exten- 
sively used at Navan, Trim, Kells, Slane, and elsewhere—even at 
great distances. 

Crossdrum.—Two miles west of Oldcastle. Whitish-grey ; very 
pure; works freely. Can be obtained in blocks of large sizes. 

Rosscastle or Cashel.—Seven miles from Oldcastle, close to Lough 
Sheelin and the mearing of the county; a very superior stone and 
in much request. It is like the Crossdrum stone, but of a finer tex- 
ture and lighter colour; is extensively used in this county and in 
Cavan and Longford, the columns in the R. C. Church of the latter 
having been procured there. It was also used in the building of 
Loughcrew House. 

Crossagh, near Rosscastle.—The stone is very similar, but coarse : 
yet it is more preferred by the builders in Dublin. 

Trim.—Dark-blue to blackish ; of the Calpy type; earthy, but 
compact ; even-bedded ; a good workable stone for plain building, 
but will not dress well. Has been used in most of the public build- 
ings in Trim, also in the old Norman castle and ecclesiastical struc- 
tures; but in the latter sandstone has been employed where cut 
stone was required. 

Drogheda.—Near Drogheda the stone is, in general, grey and 
brittle ; but to the eastward it is dark-grey to blackish; of a Calpy 
nature, and can be raised in very large blocks suitable for rough 
work. Large quarries were opened at the east margin of the town, 
from which were procured the stones to build the Boyne Viaduct ; 
the dressing and cut-stone work being brought principally from 
Ardbreccan or Milverton, near Skerries, Co. Dublin. Farther east- 
ward, adjoining the river flats, there are the Corporation quarries, 
from which were procured the stones for the extensive harbour 
improvements. 

Lime very good; made from the Carboniferous limestone and 
from the boulders in the drift. 


Monacuan. 


The limestone is of Carboniferous age, and is generally of a Calpy 
nature, not suitable for tool-work. Some of the best stones in the 


Kinauan—On Irish Marbles and Limestones. 437 


neighbourhood of Clones and Monaghan are situated in such low 
ground that they are liable to be flooded, and are, therefore, too 
expensive to work. The best quarries suitable for cut-stone purposes 
are in the neighbourhood of Carrickmacross. 
Barley Hill. Five miles from Carrickmacross.—Dark bluish- 
grey ; hard; well suited for tool-work, but rather difficult to work. 
Lime good, but often dark-coloured. 


QuEEN’s Counry. 


Carboniferous limestones occupy the central portion of this 
county. In some places the stone is of very good quality, but in 
others it is inferior, being of a Calpy type. 

Stradbally.—Light brownish-grey to grey ; close-grained ; i 
suited for cut-stone purposes. Has been largely used in this and 
the neigbouring county of Kildare. In all the public buildings 
at Maryborough it has been used; also at Monasterevan and else- 
where. 

Dunamase. Two miles from Stradbally.— Grey; compact ; 
slightly splintery ; but otherwise a good stone. 

Spire Hill.—F ive miles from Mountmellick. Grey; oolitic; 
slightly silicious; does not work freely. 

Thornbury (Abbeyleix).— Dark greyish-blue; silicious, and 
difficult to work. 

Ballyullen. One mile from Abbeyleix.—Greyish-blue. This 
is kinder and more easily worked than the Thornbury stone, and 
is more generally used in Abbeyleix. 

Portarlington.—Good stone for rough work; quarried in | dite 
ferent places, but not approved of for tool-work. 

Graigue. On the edge of the county, a suburb of Carlow.— 
The quarries here were principally worked for marble. The asso- 
ciated stones being burnt for lime. 

Lime very good, cheap, and abundant. 


RoscoMMon. 


Nearly the whole of this county is occupied by Carboniferous 
limestone, only some very subordinate tracts of older rocks appear- 
ing up through it. The rocks are very varied in character, from 
bad Calpy stones to those of the Burren type. There are, however, 


438 Scientific Proceedings, Royal Dublin Society. 


dispersed over the county, many quarries capable of producing a 
good class of stone. 

Crisnagh. Near Boyle.—Grey; semi-compact; crystalline ; 
works well and freely. 

French Park. Near Boyle.—Grey; close, and compact; a free- 
stone; works well. The quality of the stone near Boyle, and its 
suitability for tool work, were not formerly recognised. . When 
Rockingham House was built, the stones were brought sixteen 
miles from Ballinafad, Co. Sligo. Some of these stones polish 
well, and are used for tombstones. 

Hughestown. A few miles from Carrick, near the Shannon.— 
Light greyish-blue; some of a better class become of a lighter 
colour when worked. ‘This stone has been used in Carrick-on- 
Shannon in preference to the stone at Mealwood. 

Castlereagh.— Between this town and Boyle there are different 
quarries ; but the stone is more or less of a Calpy nature, and diffi- 
cult to work. Mount Sandford House, near Castlereagh, was built 
of stone brought from Bellanagore, about nine miles distant. 

Bellanagore. Seven miles from EHlphin, the quarries being 
situated a few miles to the west and south-west of the village.— 
Dark to light grey; much freer than the stones near Castlereagh ; 
but inferior to those near Boyle. 

Aughris. About two miles from Roscommon.—Dark to light 
grey ; fine; crystalline ; works freely. 

Scardaun. About four miles from Roscommon.—Dark to light 
grey ; works freely ; in character very like those of the barony of 
Burren, Co. Clare. 

Lecarrow (Knockcroghery).—Grey; finely crystalline; regularly 
bedded; in parts cherty ; works fairly well. 

Taghmaconnell_—In this stony district the rocks are of types 
similar to those in the barony of Burren, Co. Clare. Good stones 
might be procured, but no quarry of note has been worked, as the 
stones needed in the neighbouring towns of Athlone and Ballina- 
sloe are more easily procured at the latter, in the Co. Galway, and 
at Clonmacnoise, in the King’s County. 

The lime in this county is excellent and cheap. 


Kinawan—-On Irish Marbles and Limestones. 439 


S1ieo. 


In this county, as in Mayo and Galway, there are extensive 
erags and cliffs of Carboniferous limestone. The rock, however, 
is not, in general, as good a class of stone; those about Lough 
Arrow, to the south, and some beds near Ballysodare, being con- 
sidered of the best quality. Many of the Sligo stones are more or 
less of a Calpy type, and difficult to dress; yet in the old abbey at 
Sligo the local blackish stone was used for all purposes; and in 
the ruins are different examples of excellent work still in good 
preservation ; but of late years the Killea sandstone, Co. Leitrim, 
seems to have been preferred for cut-stone purposes. 

Ballysadare.—Greyish-blue ; crystalline ; semi-compact; easily 
worked ; takes a good polish; has been used for tombstones. 

Ballinafad. On the south-west shore of Lough Arrow.—In 
different places, grey and blue; crystalline; semi-compact; easily 
worked. Formerly much used before the quarries at Boyle, Co. 
Roscommon, were opened; the stones for Rockingham House, 
near Boyle, having been brought from this neighbourhood. 

Lime of the county good and cheap, but often dark-coloured. 


TIPPERARY. 


Except in portions of the barony of Lower Ormond, where it 
is of the Calp type, the limestone of this county is of a very uni- 
form blue colour, and compact. It has been very generally used 
in some of the best ancient ecclesiastical structures. On this sub- 
ject Wilkinson writes :—‘ At Cashel, with the exception of the 
sandstone used in the construction of Cormac’s Chapel and the 
Round Tower, limestone is the material with which all the build- 
ings have been erected. At Holycross this stone has been used 5 
and the beautiful ruins in both these places show the excellent 
quality of the stone, both as regards the fine work it is capable of 
receiving, and its durability ; for the mouldings of the oldest parts 
are still fresh and sharp on the ses and even preserve the marks 
of the tools used in preparing them.” 

Fir Quarry, Ballinderry. Not far from Carrick-on-Suir. Gye 
close; even-grained ; difficult to work. 

Camus. A short distance from Cashel.—Light-grey ; easy to 
work. 


440 Scientific Proceedings, Royal Dublin Society. 


Lewagh (Holycross). A little north of Thurles.—Dark-grey ; 
semi-compact; a very superior stone for all fine work. This ap- 
pears to have been the stone with which Holycross Abbey was 
built. . 
Castle Meadow. One mile from Thurles.—Grey; free work- 
ing; very good for dressed work. 

Ballinacurra. Four miles from Clonmel.—Dark greyish-blue : 
coarse and earthy beds; rather difficult to work, and more suitable 
for rubble than dressed work. 

Lisbunny. Near Nenagh.——Dark-blue, compact; earthy; in 
general not difficult to work. Some beds are more argillaceous 
than calcareous. 

Loughalton. Two miles from Nenagh.—Dark-blue to blackish ; 
some beds lighter, and greyish ; works easily. 

Loughorne. Three miles from Nenagh.—Variable in colour; 
shades of light-grey, dark-grey, and blue; in general compact ; 
the blue stones very earthy ; works easily. 

Ballinillard. Near Tipperary.—Greyish-blue. A light-coloured 
magnesian limestone lies below the blue ; works well. 

Portland.—Near to Portumna Bridge. Dark-blue to blackish ; 
earthy ; in part shaly; large blocks can be raised. Used exten- 
sively in the works on the Shannon. In this portion of the barony 
of Lower Ormond the rocks are of the Calp type, and are not in 
general suited for cut-stone purposes. 

In general very good lime ; some dark-coloured. Some of the 
Calp beds either will not burn, or will do so with difficulty. 


_ Tyrone. 


In this county are found Cretaceous, Carboniferous, and Meta- 
morphic limestones. The White Limestone (Cretaceous) occurs to 
the north-east, near Coagh and Stewartstown ; the Carboniferous 
occupies more or less scattered and semi-detached tracts; while 
the older limestones are found in bedded masses among the meta- 
morphosed rocks of Ordovician and Cambrian (?) ages in the 
north-west of the county. Dolomyte, containing Permian fossils 
like those at Cultra, Belfast Lough, Co. Down, has been found at 
Tullyconnel, near Ardtrea, a mile to the west of this place; and 
in sinking a coal-pit at Templereagh, adjoiing the Annaghone 
colliery. 


Koanaunan—On Irish Marbles and Limestones. 44] 


These Permian rocks have not been utilized. The Cretaceous 
are used principally for lime-burning, and so are also the Meta- 
morphose limestones, and in a great measure the Carboniferous. 
‘Limestone is not, in general, used for cut-stone purposes, as sand- 
stones of excellent qualities occur in different places, and they 
are usually preferred. 

Cookstown. At Railway Station.—Various shades of grey to 
pink and red; fossiliferous; crystalline; some beds compact, and 
take a good polish. In beds from an inch to 4 feet thick. A little 
east of the town is a limestone of a purplish-grey colour; compact ; 
erystalline ; works fairly. 

Broomhill. A mile north of New Mills.—A bed of hydraulic 
limestone ; 12 feet thick proved by boring. 

Drumreagh. Three and a-half miles north-east of Dun- 
gannon.—A thick bed of close-grained blue hydraulic limestone ; 
under 37 feet of thin-bedded rock. 

Keeran’s Oross. Three miles south-east of Pomeroy.—A thin 
bed of light-brown hydraulic limestone. 

Castlecaulfield—Three miles west of Dungannon. Grey ; com- 
pact; crystalline ; in places flagey, or with shaly partings between 
the beds; works fairly well. 

The Carboniferous limestone, in general, is impure and hard to 
burn, or gives a dark-coloured lime; but at Cookstown an excel- 
lent white lime is produced. 

The White Limestone in general gives a rich lime. 

In the granite to the north-west of Pomeroy, at Limehill, there 
is a peculiar compact white limestone burned for lime, but not of a 
good quality. 

Hydraulic limestones, as above mentioned, are found at Broom- 
hill, Drumreagh, and Keeran’s Cross. 


WATERFORD. 

The Carboniferous limestone occurs nearly altogether in long 
east and west basins—one in the Youghal valley, and another in 
that of Dungannon, with a small tract in the valley of the Suir. 
The limestone used in this county for dressed-stone purposes is 
principally brought from the south portion of the county of Kil- 
kenny, being procured in the quarries in the neighbourhood of 
Jcilmacow. 


442 Scientific Proceedings, Royal Dublin Society. 


Whitechurch. South of Cappoquin.—Light-grey ; hard; diffi- 
cult to dress; has been used in the town of Dungarvan, five miles 
distant ; also in the railway and other bridges. 

Shandon (Dungarvan).—Dark-grey ; not good for dressed- 
work; much inferior to that of Whitechurch, but more easily 
dressed ; used in building the Courthouse; gives superior lime. ’ 

Oughboy.—A. mile. from Lismore. Light-grey; hard, but 
brittle; coarse; easy to work. : 

Between Lismore and Dungarvan there are in places small 
quarries, where fair stone for tool-work has been procured. Some 
beds take a good polish, and have been used as marbles. 

Dunkitt.—Here, and also on the north side of the Suir (Co. Kil- 
kenny), limestone has been extensively quarried, to be sent down the 
Suir and up and down the Barrow, to supply the counties of Wex- 
ford, Kilkenny, and eastern Waterford, with stones for lime-burning. 
It is a thin-bedded, shaly, earthy stone; but as it can be cheaply 
carried by water to Waterford, it has been very extensively, though 
not always advantageously, used there. 

Good lime, but dark-coloured in general. 


WESTMEATH. 


Except in a few isolated places, Carboniferous limestones occupy 
the whole of this area. The rock is, however, comparatively speak- 
ing, seldom seen; and when it comes near the surface it is usually 
of the Calp type; or of a character unsuitable for cut-stone material. 
For this purpose limestone is principally obtained from Clonmac- 
noise, King’s Co., and Ballinasloe, Co. Galway, and formerly from 
Rosscastle, Co. Meath. A good stone, also used as a marble, occurs 
near Moate, while others have been extensively quarried about 
Mullingar, and used in that town: the stones, however, near Mul- 
lingar do not give fine or durable work. 

Hall. Three miles south-west of Moate.-—Grey, with splashes 
of white and red: of good quality, worked as a marble; extensively 
used in the new Exchange, Manchester, and in other places in 
England. 

Bunbrosna and Multyfarnham.—Dark-blue to blackish ; even- 
bedded. Various quarries, at which the stones are principally raised 
for rubble work and flagging. 


Kinanan—On Ivish Marbles and Limestones. 443 


Pakenham Hall. A mile from Coole.—Dark-grey ; crystalline ; 
fossiliferous; earthy ; a fair stone. 

Kerry. Three miles from Mullingar.—Dark-grey to blackish ; 
compact; earthy; in part shaly; works freely; used in the 
Catholic Church, Mullingar. 

Fulmore.—Seven miles from Mullingar. Dark-grey to blackish ; 
Calp type. Large stones can be raised, which were used in the 
Railway Works and Mullingar. | 

Lime good, but dark-coloured. Hydraulic limestone occurs at 
Donore, where other beds give a very good lime. 


WEXFORD. 


In this county there is very little Carboniferous limestone, as 
it only occurs near Wexford, in a strip running south-west from 
the south of the harbour to the sea, near Duncormick, and in the 
promontory of the Hook. It is not much used for building pur- 
poses, although formerly much quarried for lime-burning. It is 
more or less of the Calp type, and not well suited for cut-stone 
purposes. Large blocks can be raised, and the stone from the 
Drinagh quarries, south of Wexford, were used in the construc- 
tion of the new pier at Ballygeery in the South Bay. The quays 
also, and other buildings, have been built from similar stones, 
procured here or in the quarries in the neighbourhood. ‘The lime- 
stone at Drinagh is in part hydraulic. 

In the Ordovician rocks there are beds of limestone and calca- 
reous tuffs. The limestones are used principally for lime-burning, 
especially one bed near Courtown Harbour, which is in part 
hydraulic. The tuffose limestones dress easily, and have been 
used in the railway bridges, but they do not appear to be durable. 

Good strong but dark-coloured lime from the Carboniferous 
limestone; the Ordovician limestones also give strong dark-coloured 
lime, but not good returns. In old times, even at considerable 
distances from the coast, sea-shells were burnt into lime. 

Hydraulic lime can be made from some of the beds in the 
Drinagh quarries, while a poorer hydraulic limestone occurs at 
Courtown. 


444 Scientific Proceedings, Royal Dublin Society. 


WIcKLow. 


This is the only county in Ireland in which Carboniferous rocks 
have not been found; nor is it likely that any outlying patches 
occur under the superficial accumulations. It was also generally 
believed that no limestone of any kind exists; but of late years 
this has been proved to be incorrect. 

In the Glenart demesne, near Arklow, to the westward of the 
Castle, there is a very impure thin bed of limestone. Westward of 
Castlemacadam, near the church, in the brow of the hill, there are 
beds of flaggy limestone, which seem to have been worked to a small 
extent in former times; and to the north-east this limestone again 
appears in the brow of the hill, west of the Ovoca railway station. 
A bed of limestone was cut in the Avonmore valley when driving 
up the level from the old Glebe to Connery mine ; while limestone 
also occurs near Westaston, some few miles eastward of Rathdrum. 
None of these limestones have, at least in late years, been quarried ; 
but they appear to be of a quality very similar to the Courtown 
limestone, Co. Wexford. 


[ 445 ] 


XXXVII._—ON A PECULIARITY IN THE NATURE OF THE 
IMPRESSIONS OF OLDHAMIA ANTIQUA AND 
O. RADIATA. By J. JOLY, B.E., Assistant to the 
Professor of Civil Engineering, Trinity College, Dublin. 


[Read, November 17, 1886.] 


Recentiy, while examining some fragments of slate from Bray 
Head showing marks of Oldhamia, I noticed that on such speci- 
mens as displayed both varieties of marking, O. antiqua and 
O. radiata, the following peculiarity appeared :—A sunken or de- 
pressed delineation of one variety accompanied a raised or relieved 
delineation of the other variety. Thus, if on any specimen 
O. antiqua appeared as a depression, on that same surface the 
O. radiata appeared in relief. I verified this relation over such 
specimens as were in my possession, twelve in number, collected by 
myself at various times from certainly not less than two distinct 
localities on Bray Head: one of which is the well-known locality 
close to the Periwinkle Rocks. ‘These specimens are on the table. 

From this observation it appeared probable, if any meaning 
was to be attached to the relation, that a further relation would be 
found to obtain between the mode of delineation and the position 
in the rock. 'This was easy of investigation, as such further rela- 
tion might be sought for wherever either variety of mark was to 
be found in situ. Examination revealed the expected relation, 
in this order:—On the upper surface, or what was most probably 
the surface of deposition (the cleavage of the Cambrian slate of 
Bray Head coincides generally with the plane of bedding), the 
O. radiata appeared invariably as a depression, the O. antiqua in re- 
lief. In four localities this was verified. In one only, at the south 
entrance to the new tunnel, was there any doubt. Here the folding 
is so extensive and complicated that it was uncertain what surface 
was uppermost, and the marks also were obscure. Close to this 
fifth locality clearer marks on less contorted beds are in accord with 
the relation. It is apparent, indeed, that in the event of the relation 
being more extensively verified, it might in such cases be applied 
to determine whether or not inversion had occurred. 


446 Scientific Proceedings, Royal Dublin Society. 


An explanation of this peculiarity—which at all events evi- 
dently obtains extensively in the Bray Head rock—is not easily 
offered; but I think the polarity of the marks respecting the 
plane of deposition is of importance in this, that it establishes a 
relation between the phenomena giving rise to them and that 
plane. Thus, for example, any hypothesis ascribing their origin 
to something in the nature of crystallization of the materials of 
the rock must account for a direction of cleavage differing in the 
two varieties respecting the plane of bedding. ‘This would appear 
to render a frost-mark theory (these Proceedings, antea, p. 106) in- 
adequate to explain both forms, although the polarity in the case 
of the O. radiata would accord with the theory. On the other hand, 
it need not necessarily, I think, be opposed to an organic origin 
for both forms. 

It is observable that if fragments be peeled off the slate, it is 
often found that the marks have been transmitted, or extend, to 
layers beneath, so that lines on the upper are seen as continued on 


7 
2 


the adjacent lower surface; this, too, for thicknesses exceeding a 
millimetre. 
The accompanying woodcut recalls the appearance of a surface 


Joty—On a Peculiarity in Oldhamia antiqua and O. radiata. 447 


from the Periwinkle locality. It is seen that it is not quite 
a plane surface, but one which has developed somewhat con- 
choidally. It is rough, too, and unlike the usual bedding sur- 
face. Nevertheless the O. antigua branches over the ridges without 
sensible loss of distinctness, and undeviated. This is not an un- 
common case. The specimen in question shows the O. antiqua 
in relief, the O. radiata depressed. The specimen has been placed 
in the Science and Art Museum, Kildare-street. 


SCIEN. PROC. R.1).8.—VOL. V- PT. VI. 21 


(2 J 


XXXIX.—CURIOUS CONSEQUENCES OF A WELL-KNOWN 
DYNAMICAL THEOREM. By G. JOHNSTONE STONEY,, 
M.A., D. Sc., F.R.S., a Vice-President of the Society. 


[Read, January 19, 1887.] 


THERE is a well-known theorem in the science of Dynamics, re- 
lating to a system of bodies in motion, which may act on each 
other, but are not acted on by any external force. The theorem 
in question is, that if at any instant the velocities of the several 
bodies of the system be reversed, without any other change being 
made (?.e. without altering either their masses or the laws accord- 
ing to which they attract or otherwise act on one another), then 
will all the bodies of the system retrace their steps, traversing in 
the reverse direction the same paths which they had previously 
described, and in such manner that any position through which 
any one of these bodies had passed in its onward progress, at a 
certain time before the reversal, will be repassed with the same 
velocity, but in the opposite direction, at the same interval of time 
after the reversal. | 

Now, if we regard the universe as a dynamical system, it is 
exactly such a dynamical system as this theorem presupposes. 
Its several parts act on one another, but are not subjected to any 
other forces. And it is of interest to study what would be the 
result if such a reversal as the theorem supposes were to take place 
throughout the whole universe. We must, of course, suppose that 
the reversal affects all the motions of the universe, not only its 
‘molar motions, but its molecular motions also; and not only the 
motions of its ponderable matter, but also the motions of the ether. 

In order to be in a position to study the effects, let us first 
suppose that we are spectators of this far-reaching change, without 
being ourselves affected by it—that we are, from an intellectual 
standpoint, as it were outside the great system whose future — 
history we want to trace, simply observing everything that takes 
place, and not in any way interfering with it, nor ourselves in any 
way transformed by the change. 


Stonry—On Reversal throughout the Universe. 449 


To such a spectator the past history of the universe would 
repeat itself in reverse order, and many of the conditions under 
which it would do so would appear to him very strange. The 
bird which was shot to-day by the sportsman, and which is now 
lying in his kitchen, will, if the reversal of the universe were to 
take place at this instant, be restored by the keeper to the game- 
bag, will be carried by him, walking backwards, to the place 
where the pointer had fetched it in, where he will take it out, and 
lay it on the ground. Thence the dog will lift it in his mouth, 
and, trotting backwards, will reach the spot where the bird fell, 
where, however, it will now rise to the height at which it was shot, 
from which it will fly away backwards unharmed. Meanwhile, 
the vapours into which the powder had been dissipated will stream 
back into the barrel of the fowling-piece, and condense themselves 
again into gunpowder, while the grains of shot will rush towards 
the muzzle of the gun, and crowd into its breach. 

It is of importance to observe that, under the new conditions 
of the universe, all true dynamical laws will remain the same as at 
present, but many quasi-dynamical laws will be reversed. Thus, 
the first law of thermodynamics—the law of the equivalence of 
energy—will remain unaltered, but the second law will become its 
converse. Instead of a warmer body tending to impart heat to a 
cooler body, as at present, the new condition of things will tend to 
make their temperatures more divergent. Heat will become 
mechanical energy directly, and without requiring the accom- 
panying degradation of energy which now takes place. Friction, 
instead of retarding the progress of bodies, will help them forward. 
The air, instead of impeding a missile passing through it, will 
urge it on. And, when reviewing a system so divergent from 
what we find in the actual universe about us, it is very instructive 
to bear in mind that the wniverse, under the new conditions that we 
suppose, would be as perfect a dynanucal system as the actual universe 
is. This places before the mind in a very strong light the grave 
error which is too often made when such laws as I have referred 
_ to—the second law of thermodynamics, &c.—are supposed to be 
true dynamical laws. 

This naturally leads up to the consideration whether the laws 
of causation would be affected. Those relating to true causes 


would not be affected: those relating to quasi-causes would all be 
2H2 


450 Scientific Proceedings, Royal Dublin Society. 


inverted. ‘True causes never precede their effects; they are always 
strictly simultaneous with them. The science of Dynamics recog- 
nises true causes only. All change of the motion of a body is in 
that science attributed to forces acting while the change is taking 
place; and the persistence of a body in motion while no forces are 
acting on it is due to the inertia of the body, #.e. the body itself is 
the cause of it. It is because the inertia of a body is a sufficient, 
cause for its continuing in motion that time can elapse between 
events in nature. Whether the motion changes or does not 
change, the effect and its true cause are accurately simultaneous. 
The dispute as to whether action takes place at a distance does not 
disturb this statement. Everyone who does not suppose that the 
sun attracts the earth from a distance and without lapse of time, 
supposes that some medium pervading the intervening space com- 
municates the action; and it is not the distant body, but the sur- 
face of this medium where it touches the body acted on, that upon 
this view can alone be recognised in the science of Dynamics as the 
true immediate cause of the changes of motion of the second body. 
Thus, in all cases, dynamical effects arise along with, and not 
after, their causes. But in popular language, and indeed in all 
but very carefully strict language, many events are spoken of as 
caused by events that have preceded them. Thus, in the usual 
loose way of talking, we may speak of a ball’s having been re- 
acted on by the ground as the cause why it is now ascending, 
although a moment’s reflection would show that, in strict lan- 
guage, the reaction of the ground has caused only those changes 
of motion that occurred while the ground was pressing against the 
ball, and that the ball’s afterwards continuing to ascend is due to 
its inertia. Sometimes the two classes of causes are distinguished 
as immediate and remote. Now the change which we have sup- 
posed the universe to undergo would in no way affect immediate, 
that is, true causes; but all that we now recognise as an antecedent 
or quasi-cause would, to the spectator looking on at the universe 
from without, be changed into the effect, and that which is now 
the effect would to his apprehension occur first and become the 


cause. | 
These seem the first lessons which the study we have entered 


upon impresses upon us. But it is capable of giving further in- 
struction. Hitherto we have supposed the altered universe looked 


Stoney—On Reversal throughout the Universe. 451 


at by a spectator who was himself unaffected by the change. But 
we are all ourselves parts of this universe, and the series of 
thoughts that occur in our minds are quite as much events that 
happen in the universe as the motions we see around us. Such a 
reversal of all the velocities of the universe as I have supposed, if 
it really took place, would affect us and the motions in our brains 
as well as everything else in the universe; and we have now to 
consider what the effect of this would be, and how it would modify 
our observation of what is going on around us. From the instant 
of the supposed reversal, the thoughts which had occupied our 
minds previous to it will recur, repeating themselves backwards, 
just like every other event in the universe. The memory of 
having eaten our breakfast will present itself first; the sensation 
that we are eating it will come on afterwards: at least this is the 
order in which we must as yet describe these thoughts in our mind 
as occurring; it is the order in which they would appear to that 
outsider whom we before supposed to be surveying the universe. 
But the relation of the one thought to the other in our own mind 
—of the memory to the sensations remembered—will be after the re- 
versal exactly the same’ asit was when these same thoughts occurred 
before in their right order. Now, TIME IS ONLY AN ABSTRACT TERM 
REFERRING TO ALL SUCH RELATIONS, just as mankind is an abstract 
term referring to the individuals that are men. And just as it is 
individual men who have a real existence, and not mankind in the 
abstract, so is it the individual time-relations occurring between 
real thoughts or real events that have a real existence, and not 
time itself, which is a mere word. But as we have found that the 
time-relations between our thoughts after the supposed reversal 
are absolutely the same as the time-relations between these same 
thoughts when they occurred before the reversal, then to us, if we 
share in the reversal, our thoughts and the events in the world 
about us will seem to occur in the same order of time as they did 
before the reversal, and the moment of reversal will in both cases 
appear to us to occur last in point of time. In other words, our sup- 
position of the reversal of all the motions of the universe, when it 


1 Tn fact, the time-relation between the two states of mind amounts to this, that a 
part of the one state of mind is a memory of the whole, or of a part, of the other state 
of mind ; and this is equally the case after as before the reversal. 


452 Scientific Proceedings, Royal Dublin Society. 


embraces the whole universe, ourselves included, does not really 
involve a repetition of the events in reverse order, but only a 
second way of reviewing the past history of the world. 

These considerations do not seem altogether unfruitful. They 
emphasise the distinction between true and quasi-dynamical laws» 
they clear our thoughts with reference to the relation of cause and 
effect, and, above all, they help to dispel from our minds the 
prevalent error that time has an existence in itself independently 
of the particular time-relations that prevail between the thou ghts 
that really occupy our mind, or between events! that actually occur 
in the universe about us, or between those events and our thoughts. 
In reality, the aggregate of these individual time-relations is the 
whole of what exists in nature as a background for our conceptions 
about time. 


' Thoughts in other people’s minds are some of the events that occur in the 
universe about us ; that is, in the rest of the universe, excluding ourselves. 


4581) 4 


XL.—THE PHENOMENA OF SKATING AND PROFESSOR J. 
THOMSON’S THERMODYNAMIC RELATION. By J. 
JOLY, B.E. 


[Read, December 15, 1886.] 


Proressor J. THomson’s Thermodynamic Relation 


dt  T(v-m) 
dp L 


entails that in the case of a substance such as ice, in which the 
consequence of the transference to the substance of a quantity of 


heat, Z, is to produce a negative change of volume, the value a 


is negative, and a lowering of the melting-point, results from the 
application of pressure. 

I would suggest that to the many phenomena which have 
found an explanation in;this physical fact might be added those 
attending skating, 7.e. the freedom of motion, and, to a great 
extent, the “biting” of the skate. 

The pressure under the edge of a skate is very great. The 
blade touches for a short length of the hog-back curve, and, in the 
ease of smooth ice, along a line of indefinite thinness, so that until 
the skate has penetrated some distance into the ice the pressure 
obtaining is very great; in the first instance, theoretically 
infinite. But this pressure involves the liquefaction, to some 
extent, of the ice beneath the skate, and penetration or bite 
follows as a matter of course, the amount of penetration 
being roughly a measure of the extent to which liquefaction ob- 
tains. As the blade sinks an area is reached at which the pressure 
is inoperative, 7.e. inadequate to reduce the melting-point below 
the temperature of the surroundings. Thus, estimating the pres- 
sure for that position of the edge when the bearing area has 
become = of a square inch, and assuming the weight of the 
skater as 140 Ibs., and also that no other forces act to urge the 
blade, we find a pressure of 7000 lbs. to the square inch, sufficient 
to insure the melting of the ice at - 3°5° C. With very cold ice 


454 Scientific Proceedings, Royal Dublin Society. 


the pressure will rapidly attain the inoperative intensity, so that it 
will be found difficult to obtain bite—a state of things skaters are: 
familiar with. But it would appear that some penetration must 
ensue. On very cold ice, ‘ hollow-ground ” skates will have the: 
advantage. 

This explanation of the phenomena attending skating assumes. 
that the skater, in fact, glides about on a narrow film of water, the 
solid turning to water wherever the pressure is most intense, and 
this water, continually forming under the skate, probably resum- 
ing the solid form when relieved of pressure. From the thermo- 
dynamic point of view, the skater is the external agent, putting the 
ice through a reversed Canot’s cycle. Fluid shearing takes the: 
place of solid friction, and as the resistance thus arising is propor- 
tional to the area over which shearing obtains, that temperature at 
which the skater just obtains the requisite bite to impel himself 
will be the most conducive to freedom. Other phenomena, such as 
tearing and crushing, doubtless attend the skater’s motion, but 
such must necessarily be detrimental to freedom ; indeed, the fact 
that such phenomena do often attend the easy motion of the 
skater might be regarded as evidence against the popular notion 
that the possibility of skating is to be ascribed solely to the smooth- 
ness of the ice. It is quite certain, I think, that skating on so 
smooth a substance as plate-glass, for example, more expecially if 
accompanied with incidental tearing of the surface, would be quite 
impossible. Again, it is observable that skating on very rough 
ice is possible. Only, indeed, when the phenomena of solid fric- 
tion give place to those attending the motion of lubricated surfaces 
is there at all a comparable degree of freedom. Walking on a 
pavement greasy with fine mud occasionally recalls the aecidental 
treading on a “slide.” 

In the expression “as slippery as ice” there is revealed a con- 
sensus of opinion as to the abnormal nature of ice respecting 
friction. 


F455) 


XLI.—ON THE ANTIPODAL RELATIONS OF THE NEW 
ZHALAND EARTHQUAKE DISTRICT OF 101TH JUNE, 
1886, WITH THAT OF ANDALUCIA OF 25rnH DE- 
CEMBER, 1884. By J. P. O'REILLY, C.H., M.R.1.A., 
Professor of Mining and Mineralogy, Royal College of 
Science, Dublin. (Plate IX.) 


[Read, January 19, .1887.] 


In an address delivered before the Royal Geological Society of 
Treland on the gaseous products of the Krakatoa Eruption, I took 
occasion to call attention to the antipodal relations of Java with 
the north-west coast of South America, and argued from the fact 
of there being, in this case, two districts of marked seismic activity 
directly antipodal, that in cases where such relations exist, marked 
seismic action may be expected to manifest itself. J had, in ano- 
ther Paper read before the Royal Irish Academy 14th Novem- 
ber, 1881, argued that in centres affected by earthquake action 
the points of greatest activity generally lie on coast lines, or on 
the boundary lines of geological formations: this was subsequently 
illustrated by an earthquake map of Great Britain and Ireland, 
annexed to the catalogue of earthquakes having occurred in these 
countries, submitted to the Royal Irish Academy, 28th April, 
1884. 

The antipodal relations above referred to, as also the connexion 
of earthquakes therewith, and with coast lines and coast line di- 
rections, have recently received a remarkable illustration in the 
great earthquake of Andalucia of Christmas, 1884, and January, 
1885, taken in connexion with the earthquakes and volcanic erup- 
tions which occurred in June last in the Northern Island of New 
Zealand. 

In order to show these relations between the two countries in 
question, I have prepared a map (Plate IX.) presenting the projec- 
tion, of the antipods of the northern island and of part of the middle 
island of New {/ealand, on the map of Spain. ‘This projection is 
shaded, and the zone of maximum voleanic intensity in the northern 
island is represen'cd by cross-hatching, being limited in one direc- 


456 Scientific Proceedings, Royal Dublin Society. 


tion by the Tangaroro volcano, and on the other by White Island in 
the Bay of Plenty, also volcanic in its nature, and at present (Sep- 
tember, 1886) in active eruption. The seat of the Andalucian earth- 
quake, as also the points more markedly affected thereby, are within 
circles, the zone of greatest intensity being more deeply marked. 

It will not be out of place to state summarily the main facts 
relative to the two earthquakes thus brought into relation. 

That of Andalucia was described in Nature, vol. xxxi., p. 199 
(January Ist, 1885); also in an article, “‘The Earthquake in 
Spain,” p. 237, and in a note, p. 277, giving a reswmé of Mr. 
Jos. Macpherson’s remarks on the event, made before the Spanish 
Natural History Society, January 7th, 1885. From these it may 
be learned that a series of very violent earthquakes occurred in 
Andalucia during a period of some weeks, commencing at Christ- 
mas, 1884; that while the motion was felt so far north as Madrid, 
the district most severely visited lay in the provinces of Granada 
and Malaga, forming a parallelogram measuring about 70 miles 
from east to west, and about 35 miles from north to south. The 
eastern part of this district passed into the great range of the 
Sierra Nevada, of which the highest peaks rise to between 11,000 
and 12,000 feet above the level of the sea. The area of maximum 
destruction lay in the western sierras, and covered the ground to 
the north and south of them. The greatest amount of damage 
was done at Alhama, which was almost entirely ruined. In Arenas 
del Rey 40 persons were killed; in Albuqueros 150 ; in Olivar 10; 
in Cijar 12; and numbers of like magnitude were reported from 
many towns and villages of the three provinces affected. The 
number of persons killed was estimated officially at more than 
1000 persons. In the sketch-map published in Nature, vol. xxx1., 
p- 199, the following cities, towns, and villages, are indicated as 
having suffered shocks :—Madrid, Cuidad-real, Cordova, Jaen, 
Seville, Archidona, Granada, Antiquera, Cadiz, Malaga, Torrox, 
Almufiecar, Alham, Alfarnetejo, Periana, Jayena, Olivar, and 
Albufiuelas. 

From the remarks made by Mr. Macpherson (vol. xxxi., p. . 
278), the following additional particulars are gathered :— 

The earthquake presented marked coincidences with the geo- 
logical structure of the country affected, and was divided by him 
into three successive phases—one of relatively slight importance, 


O’Reitty—The Earthquakes in New Zealand and Andalucia. 457 


which occurred in the early morning of December 22nd, and 
which was confined to the western portion of the country, its effects 
being felt only in Galicia and Portugal; another, of the highest 
importance, which occurred three days later, namely, at 9 p.m. on 
the 25th; while the third phase included the oscillations having 
taken place during a certain period subsequently in the districts 
most severely affected by the earthquake of the 25th. ‘The earth- 
quake extended over a very considerable surface, the district 
affected to an appreciable degree, including approximately, it 
would seem, the whole country lying between Cadiz and Cabo 
de Gata, and between Malaga and the Guadarrama range. 

The shock was quite perceptible in Madrid, the direction of 
oscillation having been from north to south. The movement 
gained in intensity as it proceeded southwards, more especially 
after leaving the southern border of the central table-land, limited 
by the fault of the valley of the Guadalquiver. He called atten- 
tion to the relation of the phenomena with the geological structure 
of the peninsula, and to the broad zone of great masses of granite, 
porphyry, diabase, and other kinds of rocks which cross the pen- 
insula from Galicia to the valley of the Guadalquiver, and which, 
geologically speaking, divides the peninsula into two distinct parts. 

“his huge belt (he says), which may be regarded as one of 
the most striking features of the peninsula of our day, cuts and 
divides the archaic formations, interrupting them in the Guadar- 
rama central chain between the Sierra de Gata and the Hstrella 
range in Portugal.” This zone he considers as corresponding to a 
great line of fracture which crosses the peninsula from north-west 
to south-east, in the prolongation of which lies the region of earth- 
quake shocks described by him. He concludes :— 

“The two principal coincidences observable between the phe- 
nomena of the earthquake and the geological structure of the 
peninsula are— 

“(1) That the disturbance of December 22nd was confined to 
the regions lying to the west of the zone described ; and 

_ “(2) That the most violent shocks of December 25th were ex- 
perienced in the region intervening between the Sierra Nevada 
and the Sierra de Ronda, and precisely on the very belt which 
encloses the arciiais mountain mass of the Sierras Tejea and 


458 Scientific Proceedings, Royal Dublin Society. 


Almijara, broken and torn by the secular ‘disturbances of our 
globe.’ 

“There stood Alhama, now prostrate in the river bed; there 
Periana, a heap of ruins 3m. high; there Albufiuelas, which exists 
no longer; there Zafarraya, Nerja, Torrox, and many other towns 
and villages, all testifying to the fragility of these faults, which, 
though dating back to the Silurian period, are still apparently not 
completely welded.”’ 

The examination of the map shows that the zone particularly 
referred to by Mr. Macpherson corresponds precisely to the axis of 
the antipodal projection of the North and Middle Islands of New 
Zealand on the map of Spain: that is to the antipodal projection 
of the zone of maximum volcanic intensity of the North Island. 
Moreover, the projection of the Coromandel promontory (New 
Zealand) not only coimcides in its limits with the coast line of 
Malaga, but corresponds to the district represented as having been 
most affected. Alhama, the point of greatest destruction, lies 
exactly on the projection of the coast line of the promontory, as 
also Velez Malaga, while Malaga lies on the projection of the 
narrow headland which projects in a north-west direction from 
that promontory. 

It may thus be asserted that the zone of maximum intensity 
of the Andalucian earthquake has for antipod the promontory 
forming the Thames and Coromandel districts of the North Island 
of New Zealand, the continuation of which, to the south and east, 
is the Tauranga, or volcanic district, the seat of the disturbance of 
June the 10th, 1886. 

As regards this, not only has it been fully described by the 
local press of the country, but it has also formed the subject of 
two Government Reports—the one by Dr. Hector, Inspector of 
Mines, the other by Mr. Percy Smith, Assistant Surveyor-General, 
Auckland—Reports which have the signal merit of being both well 
done and quickly published. 

The following extract from Mr. Percy Smith’s Report (page 1) 
gives a description of the district affected :— 

“Tf a line be drawn nearly south-west (true) from the top of 
Ruawahia, it will be found to indicate very closely a line of ther- 
mal action, extending from the base of that mountain to Orakako- 


O’Reitty— The Earthquakes in New Zealand and Andalucia. 459 


rako, along which, from time immemorial, have existed hot springs, 
geysers, and fumaroles, in immense numbers. 

“Such a line will also pass along the wall-like western face of 
the Paeroa Mountain, at the base of which, in several places, hot 
springs and fumaroles have always existed. 

“A little to the north of Paeroa is the Maounga-onga-onga Hill, 
on which no signs of recent action is apparent; but immediately 
to the east of it a country with innumerable hot springs, boiling 
mudholes, and lakelets, having on the east side the Kakaramea 
Mountain, where thermal action is very active, the greater part of 
the mountain having been steamed, and boiled, and coloured by 
subterranean vapours from top to bottom. In many places it is 
only necessary to make a hole in the surface to see the steam come 
forth. Further to the north-east the same line strikes through 
Rotomahana. It is thus obvious, that this line indicates an old 
line of activity and consequent weakness of the crust of the earth, 
and it is easy to show by varying its direction very slightly, or by 
treating it as a band of moderate width, that its production north- 
_ wards would strike White Island, whilst in the opposite direction 
Tongariro and Ruapechu form the terminal points of activity 
southwards. ‘A reference to the four-mile map attached to the 
Report shows that the recent eruptions have followed very closely 
this line. Taking Wahanga as the most northerly point of 
activity, and Okaro Lake as the most southerly, it will be found to 
have extended a distance of nine and a-half miles. Along this 
line there may be said to be eight craters or points and groups of 
eruption (usimg the term crater in a somewhat extended sense, to 
include eruptions of a dissimilar character). 

“ Karthquake Cracks.—The heavy earthquake at 2 a.m. on the 
morning of the 10th June, and the constant and frequent shakes 
and tremors since, have caused cracks in several places. In the 
Waikorua Basin on the Rotorua-Galatea Road (a place where 
several cracks, one of about half a mile long and twenty yards wide, 
have been known from the earliest times), several new cracks have 
appeared, but of no great extent. We counted five across the 
path, but only one was as much as a foot in width. They 
invariably take the line of the older cracks running north-east and 
south-west. Mr. Morgan describes the cracks on the south side of 
Kakaramea to be very numerous, and in one place a spur from 


460 © Scientific Proceedings, Royal Dublin Society. 


that mountain is cracked and broken up to an extent to make 
crossing it very difficult. The north of Maounga-onga-onga is 
also much cracked.” 

In Dr. Hector’s Report, page 2, is given a description of the 
“ Great Fissure.” 

“This is the most remarkable and characteristic feature of 
the late eruption and the chief origin of the disastrous results 
which attended it. The fissure seems to commence in a narrow 
rift at the northern end from the great rent which has been 
formed in the south end of Tarrawera Mountain. This rent 
is a most wonderful feature. It is not a slip from the mountain 
side, but appears as if a portion of the mountain, measuring 
2000 feet x 500 x 300 deep, had been blown out, leaving a ragged, 
rocky chasm, from which steam was being discharged in rapidly- 
succeeding puffs. Its general direction, as far as could be ascer- 
tained, is N. 50° E., which is the general line of direction that 
would connect all the more active geysers between Tangariro and 
White Island.” 

It may be concluded from these details that the most signifi- 
cant feature of the eruption and concomitant earthquakes was the 
oreat fissure extending from Tarawera Mountain to Okara Lake, a 
distance of about nine and a-half miles. The antipod of this fissure 
projects itself on the map of Spain in the immediate vicinity of 
the celebrated defile of Despefiaperros in the Sierra Morena, which 
connects the plateau of La Mancha with the great valley of Anda- 
lucia, and from the gorge of which a magnificent view of the valley 
is obtained. If the direction of the middle course of the Guadal- 
quiver be produced, it cuts the antipod of the northern extremity 
of the fissure, that is, the point representing the antipod of Tara- 
wera Mountain. 

There is thus brought into relation three very interesting lines. 
of earth fissuring—that traversing Spain from N.W. to 8.E., that 
constituting the axis of the volcanic zone of the North Island, New 
Zealand, and the line of faulting which corresponds to the valley 
of the Guadalquiver. 

The very remarkable mine of Almaden (which forms part of a 
great band of mineralized ground, extending in a line nearly east 
and west between the village of Chillon and a point to the east of 
Almadenejos), lies within the space covered by the projection of the 


O’Re1tty—The Earthquakes in New Zealand and Andalucia. 461 


antipod of the North Island, and about 70 kilometres to the west 
of the projection of the antipod of the axis of maximum volcanic 
activity in the Northern Island. 

It is further to be remarked that the earthquake mentioned 
by Mr. Macpherson as having occurred December 22nd in Galicia 
and part of Portugal affected a space representing the antipod of 
the northern part of the middle island of the New Zealand group, 
the outline of which corresponds in places with the coast line of 
Galicia. Moreover, as Mr. Macpherson states that the shock took 
place to the west of the N.W. and S.E. zone which crosses Spain 
as described by him, it is evident that its seat was close to the west 
coast of Galicia, which corresponds so remarkably with the antipod 
of the N.H. coast of the Middle Island. 

An equally interesting feature of the comparison established 
by the map is, that the antipod of the western and more open 
portion of Cook’s Straits corresponds to the mountain ranges of 
Sierra de Gata and Sierra de Gredos; the former, very wild, and but 
imperfectly explored as yet, attains a height of 1753m. at the 
peak known as Pefia de Francia; the latter, equally wild and grand 
in its scenery, attains a height of 2661 m. in the summit known 
as La plaza del Moro Almonzor. That is to say, a strait in New 
Zealand, said to be deep, corresponds as antipod to very lofty and 
wild mountain ranges in Spain, and necessarily the seats of vast 
geological disturbances. As if to point out more strongly these 
seeming antipodal relations, there have occurred within the last 
three months two further earthquakes in Spain, as regards the 
relations of which with the antipodal points of New Zealand pro- 
jected on the map, the following details are of interest :— 

In Nature, vol. xxxv., p. 59, occurs the note: ‘‘A shock of 
earthquake was felt in the district of Beira Alta (Portugal) on the 
11th inst. (November, 1886). This district is described in Vivien 
de St. Martin’s, “Dictionnaire de Geographie Universelle,” as being 
watered by the affluents of the Deuro, the Vouga, and Mondego 
rivers; the principal towns are Vizeu and Guarda. This district 
lies, therefore, in that part of Portugal whereon falls the projection 
of the antipod of the Collingwood District, north-western extremity 
of the Middle New Zealand Island. Vizeu lies at about 32 kilo- 
metres, = 193 miles, from the projection of the coast line, while 
Guarda corresponds very exactly as antipod to Cape Farewell. 


462 Scientific Proceedings, Royal Dublin Society. 


The other earthquake recorded is that of 31st December, 1886, 
which occurred at Almeria, the antipod of which falls in the Bay 
of Plenty, at about 42°7 English miles north by east of White 
Tsland, the extremity of the line of the earthquake movements 
which shook that part of New Zealand the 10th of June last, and 
which island since is in a state of eruption. 


t ee 7 


XLI.— SUGGESTION. RESPECTING THE EPIBLASTIG 
ORIGIN OF THE SEGMENTAL DUCT. By A. 
C. HADDON, M.A., M.R.1.A., Professor of Zoology in 
the Royal College of Science, Dublin. (Plate X.) 


[Read, February 16, 1887.] 


To Dr. V. Hensen is due the credit of first discovering the epi- 
blastic origin of the segmental duct in the rabbit (Lepus cuniculus). 
He first recorded the fact in 1875 (5); but the observation appears 
to have been universally discredited, and even Balfour makes no 
mention of it in his “Treatise on Comparative Embryology.” 
In 1884 Dr. G. F. Spee (11) found that the same occurred in the 
guinea-pig (Cavia cobaya), and in 1886 Professor W. Flemming (2) 
confirmed Hensen’s account for the rabbit. 

Towards the end of 1886, Dr. J. W. van Wijhe (18) announced 
that the segmental duct arose from the epiblast in the thornback 
ray (Raja clavata), and lastly, Dr. J. von Perényi (8) has very 
recently (January, 1887) extended this mode of origin to the frog 
(Rana esculenta) and to the lizard (Lacerta viridis). 

The origin of the segmental duct from the epiblast being now 
known to occurin Elasmobranchs, Anura, Lacertilia, and Rodents, 
we are justified in assuming that this is a general and probably 
primitive mode of formation. With the above-mentioned excep- 
tions, all embryologists who have recorded observations on the 
development of the duct agree in stating that it is at first placed 
immediately below the epiblast, and that it gradually sinks within 
the mesoblast, until it comes to lie close to the peritoneal epithe- 
lium; they also all agree in deriving the duct from the somatic 
mesoblast. . 

The duct arises in the Rodents as a linear proliferation of the 
epiblast in the region opposite to the intermediate cell-mass 
(“ Grenzstrang”’ of Hensen). Flemming points out that the area 
is of variable length, not even being symmetrical. The separation 
of this solid cord of cells from the epiblast takes place trom before 
backwards, and first oceurs at a time when the mesoblastic somites 

SCIEN. PROC. R.D.S.—VOL. V. PT. VI. QI 


464 Scientific Proceedings, Royal Dublin Society. 


are still entirely continuous with the ventral (somatic and splanch- 
nic) mesoblast. Hensen, Spee, and Flemming conjectured that the 
primitive kidney is itself developed from the epiblast in these 
Mammals, but of this they produce no direct evidence. It is 
more probable that the nephridia are of mesoblastic origin, as in 
other Vertebrates. 


Fig. 1.—Transverse Section or Empryo Ragsir (4 mm. in length, stage of 16 
somites). [After Flemming. | 


The section is taken just in front of the posterior termination of the intestine. The 
right side of the figure is the left of the body. There is a small rupture in the left 
(right of figure) mesoblastic somite. a/., mesenteron (intestine); ce., coclom 
(body-cavity) ; ep., epiblast; hy., hypoblast; %.c.m., intermediate cell-mass; 
n.¢c., neural canal; s.d., segmental duct ; som., somatic mesoblast; sp., splanchnic 
mesoblast. 


Van Wijhe finds that in the ray the pronephros (Vornier) 
arises, at the commencement of Balfour’s stage I., as a continuous 
evagination from the somatopleur on each side of the body 
throughout five somites. When the hinder end of this evagina- 
tion reaches the skin, it fuses therewith, and the place of fusion is 
the rudiment of the duct of the pronephros (segmental duct). 
This grows posteriorly, gradually separating from the skin, so 
that its latest formed end is always fused with it. The meso- 
nephros (Urnier) is developed shortly after the appearance of the 

pronephros. 
; In the frog Perényi finds that the duct develops as a canal- 
like separation from the inner (nervous) cell-layer of the epiblast, 
which later associates itself with the mesoderm cells of the inter- 
mediate cell-mass (Grenzstrang). 

According to the usually-received account, formation of the 
segmental duct may take place in two ways—(1) either by the 
closing in of a continuous groove of the somatic peritoneal epi- 
thelium (Cyclostomi, anterior end only; Lepidosteus; Teleostei ; 
Amphibia) ; or as a solid knob, or rod of cells derived from the 


Havpon—On the Epiblastic Origin of the Segmental Duct. 465 


somatic mesoblast, which grows backwards between the epiblast 
and the mesoblast (Cyclostomi, posterior portion ; Elasmobranchii ; 
Amniota). 

Balfour (1), appreciating the difficulties concerning the mor- 
phology of the duct, wrote thus :—“It is quite certain that the 
second of these processes is not a true record of the evolution of 
the duct; and though it is more possible that the process observable 
in Amphibia and the Teleostei may afford some indications of the 
manner in which the duct was established, this cannot be re- 
garded as by any means certain.” 

One question always presents itself: this is—How did the seg- 
mental duct acquire its posterior connection with the cloaca? In 
the development of the duct this communication is effected later 
than its first appearance, but this, evidently, could not represent 
the ancestral condition. There are also several difficulties con- 
cerning the general homology of the nephridia themselves. 

Balfour (1) discusses the problem in the following words :— 
“Tt is a peculiarity in the development of the segmental tubes, 
that they at first end blindly, though they subsequently grow till 
they meet the segmental duct, with which they unite directly, 
without the latter sending out any offshoot to meet them (Sedg- 
wick maintains that the interior segmental tubes of the Chick form 
an exception to this general statement). It is difficult to believe 
that peritoneal infundibula ending blindly, and unprovided with 
some external orifice, can have had an excretory function, and we 
are therefore rather driven to suppose that the peritoneal infun- 
dibula, which became the segmental tubes, were either from the 
first provided each with an orifice opening to the exterior, or were 
united with the segmental duct. If they were from the first pro- 
vided with external openings, we may suppose that they became 
secondarily attached to the duct of the pronephros (segmental 
duct), and then lost their external openings, no trace of these 
structures being left, even in the ontogeny of the system. It 
would appear to me more [probable that the pronephros, with its 
duct opening into the cloaca, was the only excretory organ of the 
unsegmented ancestors of the Chordata, and that, on the elonga- 
tion of the trunk and its subsequent segmentation, a series of 
metameric segmental tubes became evolved, opening into the seg- 
mental duct, each*tube being in a sort of way serially homologous 

212 


466 Scientifie Proceedings, Royal Dublin Society. 


with the primitive pronephros. With the. segmentation of the 
trunk the latter structure itself may have acquired the more or less 
definite metameric arrangement of its parts.” 

“ Another possible view is, that the segmental tubes may be 
modified derivatives of posterior lateral branches of the prone- 
phros, which may at first have extended for the whole length of 
the body cavity. If there is any truth in this hypothesis, it is 
necessary to suppose that, when the unsegmented ancestor of the 
Chordata became segmented, the posterior branches of the primi- 
tive excretory organ became segmentally arranged, and that, in 
accordance with the change thus gradually introduced in them, 
the time of their development became deferred, so as to accord to: 
a certain extent with the time of formation of the segments to 
which they belonged. The change in the mode of development 
which would be thereby introduced is certainly not greater than 
that which has taken place in the case of segmental tubes, which, 
originally developed on the Elasmobranch type, have come to de- 
velop as they do in the posterior part of the mesonephros of 
Salamandra, Birds, &c.”’ 

In his “ Comparison of the Excretory Organs of the Chordata 
and Invertebrata” (/. c. p. 607), Balfour states :—“ The excretory 
organs of the Platyelminths are in many respects similar to the 
provisional excretory organ of the trochosphere of Polygordius. 
and the Gephyrea on the one hand, and to the Vertebrate pro- 
nephros on the other; and the Platyelminth excretory organ, with 
an anterior opening, might be regarded as having given origin to 
the trochosphere organ, while that with a posterior opening may 
have done so for the Vertebrate pronephros (this suggestion has, I 
believe, been made by Furbinger). 

‘‘ Hatschek has compared the provisional trochosphere excre- 
tory organ of Polygordius to the Vertebrate pronephros, and the 
posterior Cheetopod segmental tubes to the mesonephric tubes, the 
latter homology having been already suggested, independently, by 
both Semper and myself [ Balfour]. With reference to the com- 
parison of the pronephros with the provisional excretory organ of 
Polygordius, there are two serious difficulties :— 

“‘(1) The pronephric (segmental) duct opens directly into the 
cloaca, while the duct of the provisional trochosphere excretory 
organ opens anteriorly, and directly to the exterior. 


Happon—On the Epiblastic Origin of the Segmental Duct. 467 


(2) The pronephros is situated within the segmented region 
of the trunk, and has a more or less distinct metameric arrange- 
ment of its parts; while the provisional trochosphere organ is 
placed in front of the segmented region of the trunk, and is in no 
way segmented. 

“The comparison of the mesonephric aoe with the seg- 
mented excretory organs of the Chetopoda, though not impossible, 
cannot be satisfactorily admitted till some light has been thrown 
upon the loss of the supposed external openings of the tubes, and 
the origin of their secondary connexion with the segmental duct.” 

The difficulties concerning the phylogeny of the segmental 
duct led Sedgwick (9) to the hypothesis that the duct may be com- 
pared with “the circular canal of Meduse, which might easily be 
conceived transformed into the Vertebrate segmental duct, the 
excretory organs themselves being developed from the outer part 
of the radial canals.”” Ata more primitive stage in the evolution 
of Chordata he suggests that “the primitive alimentary canal 
acquired a well-arranged system of ducts, by which the peripheral 
excretory matters were carried to the part of the alimentary canal 
near the hind end of the primitive mouth (future anus); that, in 
consequence, the excretory pores [such as occur in the circular 
canal of Meduse] were not wanted, and were either never deve- 
loped, or, if developed, lost.” 

Sedgwick summarises his conclusions thus :—‘‘ With regard to 
the endodermal organs, the pouches [archenteric diverticula] have 
become differentiated into two kinds— 

“¢(1) Anteriorly a certain number retain their communication 
with the exterior and with the gut. 

“©(2) The majority, however, lose their connexion with the 
gut and with the exterior, but remain connected by the peripheral 
canal, which behind retains (by means of a pouch ?) its communi- 
cation with the gut. 

‘“©(3) A. posterior pouch loses its connexion with the gut 
and with the longitudinal canal, and gives rise to an abdominal 
pore. 

“The first group of pouches become the gill-slits, the second 
become the cwlom, while part of each of them become differentiated 
into nephridia, which opens into the longitudinal canal (pronephric 
or segmental duct). The last pair of pouches gives rise to a part 


468 Scientific Proceedings, Royal Dublin Society. 


of the colom, and retains its connexion with the exterior as an 
abdominal pore.” 

Lang (7) appears to have been the first to compare the pores 
which put the gastro-vascular system of Coelenterates into direct 
communication with the exterior with structures found outside that 
group. He says:—‘In certain Polyclades [Turbellaria] ramifi- 
cations of the intestine open to the exterior by excretory pores, 
either on the dorsal surface (Planaria aurantiaca d. Ch:), or on 
the lateral edge (as in a very interesting new genus of the family 
of Proceride), thus forming a complete analogy with the ex- 
cretory pores which are found at the edge of the bell in certain 
Medusee. 

‘“‘'The aquiferous system characteristic of other Platyelminths 
does not occur in the Polyclades. The secretory organs of these 
animals are formed after the type of those of the Coelenterata. 
excretion in the two groups is performed by means of diverticula 
from the intestine which open to the exterior.” 

Van Wijhe (13) believes that “the primitive Craniotes pos- 
sessed no pronephric duct, the pronephros opening to the exterior 
by a pore laterally from the gland. This orifice migrated later 
posteriorly, and its outer border developed into the duct, and 
coming into contact with the cloaca, opened into it.” He further 
goes on to say, that the epiblastic origin of the segmental duct 
will not be welcome to those who hold that the Chordata were 
descended from Annelids; but, for his part, he cannot admit the 
relationship between these types. 

Without at all committing myself to a belief in the ancestry of 
the Chordata from Cheetopod Worms, I would offer the following 
considerations as tending to show that the Vertebrate excretory 
- system is readily comparable with that of Annelids, now that the 
epiblastic origin of the segmental duct has been established. 

It is perfectly well known that the nephridia of all Inverte- 
brates open directly to the exterior, and in the segmented Worms. 
there are typically a pair of nephridia for each somite. The 
diagrams (Plate X., figs. 1 and 2) schematically represent this 
arrangement. 

It is generally admitted that the early (mot necessarily the 
primitive) Chordata were segmented, and it is not unreasonable to 
suppose that the nephridia were segmentally disposed, as there is 


Happon—On the Epiblastic Origin of the Segmental Duct. 469 


usually a marked segmental arrangement of the nephric tubules in 
ontology. ‘The peripheral orifices of the nephridia must either 
have opened directly to the exterior, or from the first debouched 
into a longitudinal canal. Various theories have been framed to 
explain the latter arrangement; but the former condition is un- 
doubtedly more easily conceived, one difficulty in this supposition 
being— What has become of the primitive external openings ? 

Accepting the proposition that the primitive Chordata ne- 
phridia opened directly to the exterior, we have only to assume 
that the lateral area along which they opened was grooved, and 
that this groove extended posteriorly as far as the anus (Plate X., 
figs. 8-5). 

From the analogy of the neural groove, there is no great diffi- 
culty in further supposing that the nephric groove was converted 
into a canal, which, becoming separated from the overlying epi- 
blast, might sink into the deeper-lying parts of the body. 

If a suggestion may be hazarded concerning the advantage of 
converting the nephric groove into the nephric duct, it may be 
pointed out that the lateral openings of the nephridia would not 
be far removed from the branchial clefts, and the need of pure 
water for respiratory purposes is emphasised by the now acknow- 
ledged fact, that each cleft was provided with its own sense-organ 
(now metamorphosed into the “thymus gland”). The develop- 
ment of the duct from before backwards supports this view. 

From recent researches on the Lamprey [Shipley, 10], Newt 
| Alice Johnson, 6], Alytes [ Gasser, 4], and Frog [Spencer, 12], it 
has been proved that in these forms the blastopore never closes 
up, but persists as the anus (¢.e. the opening of the mesenteron 
into the cloaca). 

We are justified in assuming the persistence of the blastopore 
as the anus in early Chordata: thus, if the nephric groove were 
continued round to the anus, it would practically open into the 
extreme hinder end of the mesenteron, in other words, into the 
urodeum [Gadow, 3]. 

Probably about the same time that the nephric groove was 
being converted into the nephric canal (segmental duct) the proc- 
todeeum was being invaginated. The latter would push before it 
the posterior orifice of the nephric canal, as is represented in 


Plate X., fig. 6. 


470 Scientific Proceedings, Royal Dublin Society. 


The nephridia themselves appear to be of mesoblastic origin. 
It is possible that the archinephros extended throughout the 
greater length of the body, as in Chetopod Worms, but that in 
time an anterior section (pronephros) came to be developed earlier 
than the posterior portion (mesonephros). 

The precociousness in the development of the segmental duct 
in ontogeny is not necessarily a difficulty, as it can be paralleled 
by many other organs. 

On the hypothesis just sketched out, the nephridia always open 
by their original epiblastic pores—primitively, directly to the ex- 
terior ; secondarily, into a canal separated from the epiblast : also 
the archinephros could be equally effectively functional throughout 
the whole period of its modification. 


List oF PAPERS REFERRED TO IN THE FOREGOING PAPER. 


1. Batrour, F. M., . Treatise on Comparative Embryology, vol. u1., 
1881. 


2. Fiemmine, W., . ‘Die ektoblastische Anlage des Urogenital- 
systems beim Kaninchen.” Arch. f. Anat. 
u. Phys.-Anat. Abtheil, 1886. 


3. Gapow. Hee. . ‘Remarks on the Cloaca and on the Copu- 
latory Organs of the Amniota,” Proc. Roy. 
Soc., 1886. 

4, Gasser, E., . . “Zur Entwicklung von Alytes obstetricans.” 


Stizungsber. d. Marburger Naturgesell, 1882. 


5. Hensen, V., . . ‘*Beobachtungen tiber die Befruchtung und 
Entwickelung des Meerschweinchens und. 
Kaninchens,”’ Arch. f. Anat. u. Phys., 1875. 


§. Jounson, A.,. . “On the Fate of the Blastopore and the 
Presence of a Primitive Streak in the 
Newt (Triton cristatus),’’ Quart. Journ. of 
Micr. Sct., xxiv., 1884. 


s 


10. 


ite 


12. 


13. 


Happon—On the Epiblastic Origin of the Segmental Duct. 471 


. Lane, A., 


. PERENYI, J. VON, 


Sepewick, A., 


Suretey, A, E., 


Sresz, G, F., . 


Spencer, W. B., 


Wise, J. W. van, 


«Sur les Relations des Platyelmes avec les 
Celentérées d’un cété et les Hirudinées de 
Vautre,’’ Arch. de Biologie, u., 1881. 


“Die ectoblastische Anlage des Urogenital- 
systems bei Rana esculenta und Lacerta 
viridis,’ Zool. Anz., X., 1887. 


‘On the Origin of Metameric Segmentation 
and some other Morphological Questions,” 
Quart. Journ. of Micr. Sci., xxiv., 1884. 


‘©Qn the Formation of the Mesoblast, and 
the Persistence of the Blastopore in the 
Lamprey,” Proc. Roy. Soc., 1885. 


‘“‘ Ueber directe Betheiligung des Ektoderms 
an der Bildung der Urnierenanlage des 
Meerschweinchens,” Arch. f. Anat. wu. 
Phys. Anat. Abtheil., 1884. 


‘Some Notes on the Early Development of 
Rana temporaria,’ Quart. Journ. of Micr. 
Sct., Suppl., xxv., 1885. 


“Die Betheiligung des Ektoderms an der 
Entwicklung des Vornierenganges,’’ Zool. 
Anz., 1X., 1886. 


[Expianation oF Puate X. 


472 Scientific Proceedings, Royal Dublin Society. 


EXPLANATION OF PLATE X. 


Diagrams Inuustratinc THE PRopasBLE EivoLutTIoN oF THE SEGMENTAL. 
(ArcuinepHRic) Duct. 


a., primitive anus, or urodzum (blastopore) ; al., alimentary canal ;. 
ao., dorsal aorta; cw., celom; ¢.o., external orifice of nephridium ; 
gl., glomerulus of archinephros; gr., nephric groove; 7%.0., internal 
(ccelomic) ciliated orifice of nephridium; pr., proctodeum (epi- 
blastic cloaca); s.d., segmental (archinephric) duct. 


Fig. 1.—Horizontal view of the arrangement of the nephridia in Seg- 
mented Worms. 


», 2.—Transverse section through the body of an Karthworm (Lum- 
bricus). 


», 9.—Transverse section through the trunk of a hypothetical 
primitive representative of the Chordata. 


» 4.—End view of the same, to show the anus lying within the 
nephric groove. : 


», 9.—Horizontal view of probable disposition of the nephridia of the 
same. 


-,, 6.—Horizontal view of ideal archinephros of the lower Verte- 
brates. 


Lee 


XLIII.—NOTE ON THE ARRANGEMENT OF THE MESEN- 
TERIES IN THE PARASITIC LARVA OF HAL-— 
CAMPA CHRYSANTHELLUM (Peach). By A. C. 
HADDON, M.A., M.R.I.A., Professor of Zoology in the 
Royal College of Science, Dublin. (Plate XI.) 


[ Read, February 16, 1887. ] 


In 1859 L. Agassiz recorded from the east coast of North America: 
an Actinia parasitic on Meduse, which he named Bicidium para- 
sitica. This has since been found by Verrill in 1862, and by 
A. Agassiz in 1865. Still more recently (1884), Mark ' has given 
a preliminary account of a larval Edwardsia, which is parasitic 
within the gastro-vascular canals of the Ctenophore Mnemiopsis. 
leidyi. 

On this side of the Atlantic, T. Strethill Wright, in 1859, gave 
an account of a small Actinia, also parasitic, on Hydromeduse,. 
from the Firth of Forth, which he named Halcampa Fultoni; and, 
in the following year, F. Miiller described a similar form, which 
he named Philomedusa vogtii, from the Santa Catherina, on the 
Italian Riviera. EH. Graeffe described, in 18838, a parasitic Hal- 
campa from the Adriatic, which, “as the development of Halcampa 
chrysanthellum is not known, this form must, provisionally, be 
separated from H. chrysanthellum as H. medusophila.” 

The author exhibited, and made remarks upon, two specimens 
of a parasitic Haleampa at a meeting of the Royal Irish Academy,, 
on June 22, 1885, and a record was published in the following 
year. In this communication it is stated that Prof. A. Macalister 
of Cambridge (late of Dublin) had informed the author, by letter, 
that he had met with this Halcampa, and perhaps another form, 
but neither of them in Dublin Bay. Specimens were also obtained 
in Dublin Bay in June, 1886, and on June 6, in the same year, off 


1 «¢ Selections from Embryological Monographs,’ compiled by A. Agassiz, W. 
Faxon, and E. L. Mark, Bull. Mus. Comp. Zool., Harvard Coll. (Camb., U.S. A.),. 
p- 43, pl. xii. 


474 Scientifie Proceedings, Royal Dublin Society. 


Ballycotton, Co. Cork. On the same day Halcampa chrysanthellum 
was dredged from fifty-two fathoms. 


Breuiograpyy oF Larva Actintm Parasitic on MeEpusa. 
North European Seas. 
Peachia fultoni, t . TT. Strethill Wright, 1859, Proc. Roy. Soc. 


Edinb., 11., p.91, 1860 ; New Edinb. 
Phil. Journ., xi., p. 156. 


Halcampa, ,, ‘ . Reprinted in Ann. Mag. Nat. Hist. (8), viii., 
1861, p. 132. 
9 5 ; . G. Leslie and W. A. Herdman, 1881, Jn- 


vert. Fauna of Firth of Forth, p. 68 
(merely repeats Wright’s record). 
Philomedusa ,, ; . A. Andres, 1888, Le Attinie, Atti. Ace. 
Rom, (8 4). xiv. (Fauna, u. Fl. d. 
Golfes v. Neapel (1884), p. 114.] 


Halcampa chrysanthellum, A. C. Haddon, 1886, Proc. Roy. Dublin 
Soc. (N.;8.), Vv: p. 115 Proc. Roy: 
Irish Acad. (2), iv., Sci., p. 527. 
(Noted in Zoologist, 1886, p. 7). 


There can be little doubt concerning the justice of considering 
the above to be the larval form of Halcampa chrysanthellum ; the 
form, colour, structure, and histology support this conclusion. 

In the only three localities where the parasitic larva has been 
hitherto found the adult Halcampa chrysanthellum has also been 
obtained, viz. Firth of Forth (Leslie and Herdman, Joc. cit., p. 62, 
on the authority of F. E. Schulze, “ Zoologische Ergebnisse der 
Nordseefahrt,” 111. Coelenterata, p. 140: Berlin, 1874), Dublin 
Bay, and Cork (A. C. H.). 

In a former paper [Proc. Roy. Dubl. Soc. (x.s.), v., 1886, p. 1] 
I have endeavoured to show that the forms known as Edwardsia 
duodecimeirrata, Sars (from Norway and E. Denmark), Zanthiopus 
bilateralis, Kef., and X. vittatus, Kef. (from N. France), are one 
and the same with this species. If this be so, the parasitic larva 
must have an equally North European range. 


Happon— On Parasitic Larva of Haleampa. A475: 


Mediterranean. 


Philomedusa vogtvi, . . Fritz Muller, 1860, Wiegmann’s Archiv f.. 
Naturg., xxvi., p. 57 [reprinted in 
Ann. Mag. Nat. Hist. (3), vi., 1860, 
p. 482.] 


A Aan . A. Andres, 1888, Le Attinie, Atte Acc. Rom. 
(84), xiv. [Fauna u. Fl. d. Golfes 
v. Neapel (1884), p. 112]. 


Halcampa medusophila, . H. Graeffe. 1883, Boll. d. Soc. Adriatica di 
Sct. Nat. Trieste, vii. 


As Halcampella endromitata (Andres), is the only Mediterranean 
example of the Halcampide, the above-mentioned forms are pro- 
bably the parasitic larva of that species. 


Coast of New England—North-East America. 


Bicidium parasiticum, . A. Agassiz, 1859, Proc. Boston Soc. Nat.. 
Hist., vil. (1861), p. 24. 

Ms . A. E. Verrill, 1862, Mem. Boston Soc. Nat. 
Hist. 1. (1866); p. dil; pli, nese 
14, 15. 


H.C.and A. Agassiz, 1865, Seaside Studies 
in Natural History, Boston, p. 15, 
fio. 14. 

Peachia parasitica, . . A.K. Verrill, 1866, Proc. Boston Soc. Nat. 
Hist., x., p, 388. 

A. BE. Verrill, 1873, Report U. S. Fish 
Com., 1., 1871-2, p. 739. 

Philomedusa ,, és . A. Andres, 18838, Le Attinie, Atti. R. Ace. 

Lincet, Rome (84), xiv. (Fauna uw. 

Fl. d. Golfes v. Neapel, 1884, p. 112, 

fig. 9. 


99 29 


From Verrill’s accounts (1862 and 1866) there can be no doubt 
that the above parasitic Anemone is really a Peachia; it must, 
therefore, be known, for the present, as P. parasitica ; but in the 
latter paper Verrill states that it is very much like Stphonactinia 
(Peachia) Beckii (Dan. & Kor. 1856) in form and colour. The 


476 Scientific Proceedings, Royal Dublin Society. 


colour is purplish-brown, or red, and the length 32 mm. - to 46mm. 
With the exception of two specimens of very large size found 
buried in the gravel, at low water-mark, at Eastport, Maine 
(Verrill, 1873), this form is only known as parasitic in the lip-folds 
of Cyanea arctica, from Cape Cod to the Bay of Fundy. 


Southern Ocean. 


Actinia clavus, : . Quoy et Gaimard, 1833, Voyage de lV’ As- 
trolabe, p. 150, pl. x., figs. 6, 11. 

Iluanthos  ,, : . Milne Edwards, 1857, Hist. Nat. des Coral- 
liatres, 1., p. 284. 

Philomedusa clavus, . . Andres, 1883, Le Aittinie, Atti. Acc. Rom. 


(3 a) xiv. [Fauna u. Fl. d. Golfes v. 
Neapel (1884), p. 114.] 


Halcampa a : . RK. Hertwig, 1882, Actiniaria, ‘‘ Challenger ”’ 
Reports, p. 92. 


Quoy and Gaimard found several specimens of this Halcampa 
entangled (engagés) in the tentacles of a medusa. It was 7-8 
lines long in its greatest extension, and only three when con- 
tracted; translucid white in colour; 12 short tentacles. They 
obtained it in Bass’ Straits, Australia, lat. 38° S. 

R. Hertwig identifies an Halcampa dredged by the Challenger 
at Kerguelen (25-120 fathoms) as this species. 

It is interesting to observe that certain (at least) of the 
members of the three families, Hdwardside, Halcampide, and 
Siphonactinide, pass through a stage during which they are para- 
sitic on Medusee or Ctenophores. ‘There is now a good deal of 
evidence in favour of the view, that the Hdwardside and Halcam- 
pidse are more closely related than was formerly thought to be the 
case; and, so far as my investigations on Peachia have gone, I am 
led to believe that the Siphonactinide are closely related to the 
latter. Be this as it may, the genus Philomedusa must now be 
discarded. 


As before mentioned, in 1885 I found one or two specimens of 
the larval Halcampa in Dublin Bay, and again in 1886, in July of 
that year, I also found a specimen off the coast of Cork. ‘They 


Happon—On Parasitic Larva of Haleampa. 477 


were usually attached to the stomach on the sub-umbrella (Pl. X1., 
figs. 1, 2) of different species of Leptomeduse. Occasionally they 
adhered to the margin of the disc. With a little care they can be 
kept alive some time, and will feed on small pieces of meat when 
medusze are not to be had. 

When first obtained some specimens measured a little under 
3 mm. in length, and one grew to about 5 mm. in length. 

The body was sub-conical in form, the column not being dis- 
tinctly divided into the three regions (capitulum, scapus, and 
physa) so characteristic of the adult. The middle portion was 
especially corrugated, and indented at the insertion of the mesen- 
teries. ‘The body could be slowly lengthened or contracted ; it 
was uniformly clothed with small cilia. There were only eight 
short tentacles. At first they were very short, but afterwards they 
grew relatively longer. 

The Medusa appears to be but little incommoded by the 
parasite ; but it probably succumbs in time to its guests. In its 
ordinary condition the Anemone sinks in the water when taken 
from the Medusa; but it can extrude its mesenteries through its 
mouth for a considerable distance (Pl. XI, fig. 5). These enable 
it to float at the surface of. the water, and, at the same time, to 
attach itself to passing Medusx. This is probably the manner by 
which it secures a continual supply of food. 

They had a uniform yellowish flesh-colour, with eight rudi- 
mentary tentacles. The tentacles grew longer, and were tinged 
with brown and yellowish white. The disc also became variegated 
with brown, and the body translucent, revealing the yellow ceso- 
phagus. At the last observed stage the body was almost colour- 
less—the cesophagus yellow, the capitulum possessed a pair of 
cream-coloured spots below each tentacle, and the insertion of the 
mesenteries were of the same colour—the eight tentacles had on their 
oral surface two transverse bars of white at the base, and a single 
bar half-way along their length. Above this was a large brown 
spot, and a pair below it; and above the basal lines, between the 
two brown spots, is a small white one. The disc was prominent, 
with white radial lines, the areas being brown, finally speckled with 
white, each having prominent white spots at the mouth. 

Although there were eight tentacles there were twelve mesen- 
teries. The tentacles were arranged in two groups of three, and a 


478 Scientific Proceedings, Royal Dublin Society. 


single tentacle between each group. A deep siphonoglyphe, was 
present, thus causing the mouth to be T shaped. The siphono- 
glyphe, being in the axial line, indicates the disposition of the 
tentacles. On reference to Pl. XI., fig. 4, it will be seen that 
the intermesenterial chamber on each side of the axial or directive 
chamber is produced into a tentacle. Of the three remaining 
lateral chambers, only the centre possesses a tentacle. 

All the previous accounts of the parasitic larva of Halcampa 
agree in the fact of twelve tentacles being present. This can only 
be accounted for by supposing that the larvae were more developed 
than mine. This was certainly the case in Strethill Wright’s 
specimens, and in my oldest examples I found indications of the 
sprouting of some of the missing tentacles. It is, of course, 
possible that the Mediterranean form acquires its twelve tentacles 
very early. 

Meyer and Mobius (Arch. f. Naturg., 1863, p. 70) mention that 
in their adult examples of “ Kdwardsia duodecimcirrata,” Sars. 
[ Halcampa chrysanthellum |, the number of tentacles varied from 
eight to twelve, but never more than the latter number. 

By making a series of transverse sections I was enabled to trace 
out the arrangement of the mesenteries ina more satisfactory man- 
ner than could be effected by an examination of the living animal. 

In the esophageal region, the twelve mesenteries appear to 
have equal importance. The siphonoglyphe causes what may be 
termed the ventral directive mesenteries to be much bent. At the 
lower extremity of the cesophagus four of the mesenteries fall short 
of joining the cesophagus. The siphonoglyphe extends for a short 
distance beyond the cesophagus proper (Pl. XI., fig. 8). 

In the gastric region of the body there are eight large mesen- 
teries, which alone bear the swollen digestive borders. It will be 
noticed that it is those intra-mesenterial chambers, bounded by a 
strong and a weak mesentery, which are not prolonged into ten- 
_tacles. The dorsal directive mesenteries also appeared somewhat 
smaller than the remaining six. The same general arrangement 
occurred at the posterior end of the body, except, of course, that 
the mesenteries have no thickened edges. 

It is probable that at a slightly earlier stage only the eight 
strong mesenteries are present, as an increase in the number of 
tentacles with the growth of the animal is characteristic of most 


Havpon—On Parasitic Larva of Halcampa. 479 


sea-anemones, and in our species the adult has twelve rudimentary 
mesenteries in addition to the twelve primaries [ cf. Proc. Roy. Dub. 
Soc. (N.S.) v., 1886, p. 12, fig. 4]. The same occurs in H. arenacea, 
Haddon’; but according to R. Hertwig, there are only the twelve 
primaries in H. clavus, Quoy et Gaimard. 

The brothers Hertwig' first insisted upon the systematic im- 
portance of the disposition of the muscular bands on the mesenteries. 
A comparison of the diagrams on Pl. XI. will demonstrate the fact 
that the eight strong mesenteries of the larval Halcampa perfectly 
corresponds with the eight mesenteries of Hdwardsia. The Hert- 
wigs have further shown that the normal Hexactina pass through 
a stage in which there are eight strong and four weak mesenteries 
(Pl. XI, figs. 10, 11); but it will be seen that these mesenteries do 
not correspond with those of the larval Halcampa and adult 
Edwardsia on the one hand, or with those of the Octactiniz on the 
other. 

The inequality in the development of the septa of the adult 
Halcampa was first pointed out by R. Hertwig? (Actiniaria, “ Chai- 
lenger”” Reports, Zoology, vi., 1882, p. 95). He found that four 
were somewhat smaller than the eight others. I have quoted (doc. cit. 
pp. 7, 8, footnote) an observation of Dixon’s confirming this, and 
Strethill Wright found the same in his larval form. He says :— 
“Hight septa were continued downwards to the lower extremity of 
the body, and had their free edges bordered by a convoluted cili- 
ated band, furnished with cnidee, or thread cells; the intersepta 
(¢.e. the four smaller mesenteries) bore no convoluted bands.” 

On a future occasion I propose to give a detailed account of the 
anatomy of Halcampa chrysanthellum; for the present I would 
merely state that I find that, in the adult, the generative organs 
only occur on six mesenteries. These correspond with the eight 
strong mesenteries mentioned above, less the dorsal pair. The 
axial, or directive mesenteries, which support the siphonoglyphe, 
are here considered as the ventral, and the opposite pair as the 
dorsal. 

The Hertwigs also pointed out that the Actinide (larval forms) 


1 First Report ‘‘On the Marine Fauna of the South-west of Ireland—Actinozoa,’” 
Proc. R. Irish Acad. (2) iv. (Sci.), 1886, p. 616. 
2 Die Actinien (Studien zur Blattertheorie), O. and R. Hertwig, Jena, 1879. 


SCIEN. PROC. R.D.S.—VOL. V., PT. VI. 2K 


480 Scientific Proceedings, Royal Dublin Society. 


Edwardsie, and Alcyonaria exhibit three different ways in which 
the eight mesenteries may be disposed. ‘They regarded the mesen- 
teries as symmetrical—/.e. four dorsal and four ventral in the 
Actinide, as six dorsal and two ventral in the Edwardsiz, while 
in the Alcyonaria all the eight mesenteries are dorsal. 

Although my observations are incomplete, I have thought it 
desirable to place them on record, as it may be some time before I 
am able to discuss the question at greater length. For the present, 
we may assert that, although the adult Halcampa closely re- 
sembles the ordinary Actinize in the ratio of its tentacles, and the 
disposition of its mesenteries, the larval form is undoubtedly more 
nearly related to the Edwardsie. 


EXPLANATION OF PLATE XI. 
(Figs. 6-14 are purely diagrammatic.) 
Fig. 1—Thauwmantias globosa, Forbes (Phialidium variable, Heckel), 
with parasitic Halcampa; nat. size. 


2.—The same; magnified 4 diameters. 


3.—Parasitic larva of Halcampa chrysanthellum, older than that 
of fig. 1; magnified 5 diameters. 


4.—Oral disc of a still older larva, with eight tentacles, but 
twelve mesenteries, and showing the siphonoglyphe. 


5.—Oral aspect of larva with extended mesenteries; about 5 
diameters. 


6.—Transverse section of larval Halcampa through the middle of 
the cesophagus (stomodzum). 


», %.—Transverse section of larval Haleampa through the lower 
portion of the cesophagus (stomodeum). _ 


»  %—Transverse section of larval Halcampa immediately below 
cesophagus (stomodeum). 


Havpon—On Parasitic Larva of Halcampa. 481 


Fig. 9.—Transverse section of larval Halcampa in the gastric region. 


», 10.—Transverse section of young larva of Aptasia diaphana (after 
R. and O. Hertwig). 


», 11.—Transverse section of slightly older larva of Aptasia diaphana 
(after R. and O. Hertwig). 


», 12.—Transverse section of adult Hdwardsia tuberculata through the 
cesophagus (after R. and O. Hertwig). 


+, 13.—Transverse section of adult Alcyonium digitatum through the 
cesophagus. 


+, 14,—Transverse section of adult Funiculina quadrangularis through 
the cesophagus (after A. Milnes Marshall). 


2K2 


be J 


XLIV.—NOTE ON A GRAPHICAL METHOD OF SOLVING 
CERTAIN OPTICAL PROBLEMS. By HOWARD: 
GRUBB, F.R.S. 


[Read February 16, 1887.] 


In the calculation of curves of optical lenses it is frequently re- 
quired to add and subtract reciprocals; and formule of the form 
1 ip teal 
at ave 

are of constant recurrence. 

In the study, where a logarithm book is available, the arith- 
metic of this is generally very simple; but in the workshop or 
laboratory a graphical method of solving the problem is often 
more convenient, particularly in the hands of workmen who have 
not had a mathematical training. 

In the working out of some optical diagrams on logarithmic 
paper I accidently arrived at the following graphical solution, 
which I have found very useful, and on the principle of which I 
am constructing a calculating machine suitable for solving these 
particular problems :— 


Draw a horizontal line = the a of above formula, and erect at one 
extremity a vertical = 3. Join the extremities of these two lines. 
Bisect the right angle, and produce the bisecting line till it reaches 
the line joining the extremities of the lines a and 8. From the 


Grupp—Graphical Method of Solving Optical Problems. 483 


point of intersection drop a perpendicular on the line a, and the 
length of this perpendicular on the same scale will be equal to in 


above formula, or = mec 3 
at B 
According to this principle, a machine can be constructed in 
which the various quantities can be read off by scales, without any 
calculation whatever. 
I hope shortly to be able to exhibit such a machine to the Royal 
Dublin Society. 


r 484 J 


XLV.—AN EXPERIMENT ON THE SURFACE TENSION OF 
LIQUIDS. By A. R. WALSH. (Communicated by F. T. 
Trovuton, B. HE.) 


[Read, February 16, 1887.] ' 


THE fact that an oily needle will float on the surface of water has. 
been known for a long time, and is often referred to as an experi- 
ment illustrating the tension of the surface between water and 
air. 

If a medium-sized needle (No. 6) is placed floating on water, 
and olive oilis gently poured on the surface of the water, until 
the needle is covered by the oil, the needle sinks to the bottom of 
the water. 

But if the same experiment be made, using this time petroleum 
instead of olive oil, the needle will remain floating on the surface 
of the water. 

The depression formed by the needle and oil resembles a boat, 
the sides of which are formed by the depressed surface of the 
water, while the contents consist of the oil and the needle. 

If the needle used in the two experiments be the same, the 
amount of oil in the boat depends upon the specific gravity of the 
oil; while the amount of oil the boat will bear without the sides 
giving way depends upon the strength of the sides, that is to say, 
on the superficial tension. 

Let 

V and be the volume and density of the water displaced ; 
V’ and &’ be the volume and density of the oil in the boat ; 


V’ and 8” be the volume and density of the needle ; 
then 


Wa WSs eX (1) 

[es ok. IM, (2) 
7 ae = 

Ye (3) 


Since o’ is always nearly equal to 6, and small compared with 8”, 


Watsu—On the Surface Tension of Liquids. 485: 


the value of the fraction in (3) depends upon the value of o. 
The volume of water displaced, therefore, varies as V” and as 0. 

The following Table, taken from the memoir of M. Quincke, 
gives in grammes weight per lineal metre, the tension of the 
surface at 20° C., separating water from air, olive oil, and petro- 
leum :— 


Superficial Tension in Grammes Weight per Lineal Metre. 


Between water and air, : ‘ . 8:253 
Between water and olive oil, . . 2:096 
Between water and petroleum, . 6 PPI: 


Specific Gravities. 


Olive oil, . : ; 3 : Sco) le 
Petroleum, . ; : : 5 SeOA0. 


When olive oil is poured on the surface of water upon which 
a needle is floating, the high specific gravity of the oil, and 
the weakness of the surface separating it from water, combine 
together to sink the needle. 

In order that a needle should be able to float between olive 
oil and water, it would be necessary for the weight of water dis- 
placed to be twice as great as the weight of water displaced when 
the same needle floats between petroleum and water. 

With a certain needle, the volume of the water displaced was 
found to be thirty-five times the volume of the needle. 

In order that the same needle might float between olive oil 
and water, the volume of water displaced would require to be 
seventy times the volume of the needle. 

It is possible for a very small needle to float on water which is 
covered by olive oil; for by halving the volume of the needle, the 
volume of the water displaced is at the same time halved. 


[ 486 ] 


XLVI.—THE BLACK MARBLE OF KILKENNY. By W.N. 
HARTLEY, F.R.8., Professor of Chemistry, Royal College 
of Science, Dublin. 


[Read, February 15, 1887.]} 


Tus well-known marble is highly esteemed on account of its jet- 
black appearance and the high polish which it is capable of receiv- 
ing. Last April I visited the quarries from which it is procured, 
and observed certain properties belonging to it of which I can find 
no description. It is mentioned in Sir Robert Kane’s work on 
“The Industrial Resources of Ireland”? that the exposed and 
weathered surfaces of the rock possess a yellow ochreous colour. 
This might be due to the colour of the freshly-hewn stone being 
caused by the presence either of ferrous sulphide or of ferrous 
carbonate, which, in presence of carbonic acid and air, became dis- 
solved and oxidised. ‘The disappearance of the black colour from 
the surface was remarkable. On striking a block of the marble 
with a hammer or large stone it emitted a ringing metallic sound. 
When portions were broken off, the fractured surface smelt of sul- 
phuretted hydrogen. Under similar circumstances the German 
“Stinkstein”’ is said to smell of bituminous matter. The con- 
stituents of the mineral were determined by Mr. J. HK. Purvis, a 
student in the Royal College of Science; the results of his exami- 
nation are here given :— 


CuEmicaAL ANALYSIS. 


When the mineral was finely powdered and thoroughly mixed 
its colour was a little lighter, but still what may be described as 
black. Carbon dioxide was determined by Fresenius and Will’s 
method: the escaping gas smelt of sulphuretted hydrogen. 

Estimation of Sulphuretted Hydrogen.—It was found by Mr. 
Fred Ibbotson, who made a qualitative examination of the 
mineral, that sulphuretted hydrogen was liberated by acetic 
acid, also that precipitated ferrous sulphide is decomposed by 
acetic acid; therefore nothing could be learnt by dissolving the 


HarriEy—On the Black Marble of Kilkenny. 487 


mineral in acetic acid. The gases evolved by hydrochloric 
acid acting upon ten grams of the substance were passed 
through two U tubes containing acidulated solution of copper 
sulphate: a brown precipitate formed only in the first limb 
of the first tube; this was collected on a filter, washed, dried, and 
weighed. It was considered that as the quantity collected was very 
small, and water was contained in the mineral, that the sulphu- 
retted hydrogen was in solution in fluid enclosures too small to be 
visible, and that possibly it was present as calcium sulphydrate. 
A large quantity of the substance was crushed under distilled 
water, and on testing the liquid with lead paper a black stain of 
Jead sulphide was obtained. The aqueous solution was filtered ; 
the filtrate was evaporated to dryness, and a light-brown residue 
was left. Hxamined with the spectroscope, the residue was found 
to contain a compound of calcium only. Another portion, crushed 
under water, filtered, and treated with ammonium chloride, am- 
monia, and ammonium oxalate, yielded a white precipitate, small 
in amount, and consisting of calcium oxalate. A portion of the 
residue left after evaporation of the aqueous solution was oxidised 
with nitric acid, and tested with barium chloride, by which treat- 
ment a precipitate of barium sulphate was obtained. 

Copper.—After solution of the mineral in hydrochloric acid 
and evaporation to dryness, to separate silica in the usual way, a 
current of sulphuretted hydrogen, passed for some time through the 
hot solution, separated a small quantity of copper sulphide. This 
was filtered, washed, dried, transferred to a crucible, heated with a 
few drops of stroug nitric acid, and the iron precipitated by ammo- 
nium chloride and ammonia, dried, and weighed. 

Calcium and Magnesium.—These were precipitated in the usual 
manner. 

Organic Matter.—The black residue, insoluble in hydrochloric 
acid, was collected on a weighed filter, washed well with hot water, 
and dried at a temperature of 100°C. A weighed portion of this 
was placed in a platinum boat, and burnt in a current of oxygen ; 
a very slight residue, apparently ferric oxide, remained. The carbon 
dioxide and water were collected in the usual manner and weighed. 
The organic matter was almost entirely carbon: no hydrogen could 
be calculated from the amount of water collected, hence the car- 
bonaceous matter was apparently of the nature of anthracite. 


488 Scientific Proceedings, Royal Dublin Society. 


To ascertain whether bituminous substances were present, the 
crushed mineral was treated with pure alcohol, which was first 
proved to leave no residue on evaporation. The liquid was filtered, 
the filtrate evaporated to dryness, and a light-brown residue 
obtained. A portion of this was moistened with a drop of hydro- 
chloric acid, and an addition of ammonium chloride, ammonia, 
and ammonium oxalate yielded a precipitate of calcium oxalate. 
Another portion, treated with nitric acid and subsequently with 
barium chloride gave a precipitate of barium sulphate. A similar 
result was obtained by treatment with pure ether. In neither 
Instance was any organic matter dissolved. These extracts by 
alcohol and ether prove the existence of calcium sulphydrate in the 
mineral; hence the odour when the mineral is broken. The ana- 
lytical numbers are the following :— 


(al) (2.) 
Per Cent. Per Cent. 
CO, .  . 140-409 . . 40-409 
CaO, . . 90°360 . - 94:920 
FeO, .. : 0-342. : 0°290 
CuOn |e inO: 0545 ee 0067 
MeO; 4.) 0248 5. =» 0.249 
SiON fare) ee lea gGr eee eT aOs 
Water, . 5 OriOG 5 5 
Carbon, . a ASB ~7 27091 
Sulphur, 5 MOS 
99°935 99°331 


1 Mean of three determinations. 


F 489.4 


XLVII—MARBLES AND LIMESTONES. By G. H. KINAHAN,. 
M.R.I. A. 


[Read, February 16, 1887. ] 


[This Supplement to the Paper on Marbles and Limestones (vide ante, p. 372) is 
a list of some limestone quarries used of late years in public and private works, pro-- 
eured through R. U. Roberts, Esq., Commissioner of the Board of Public Works. Each 
detailed description, where possible, has the name of the Officer (in brackets) after it. 
This list being supplementary to the previous Paper, for the most part only refers to 
quarries not therein mentioned, except in those cases where, in connexion with recent 
buildings, the stones have been procured from some of the well-established quarries. | 


ANTRIM. 
CRETACEOUS. 


Drumnasol—Drumnasol Lodge. The rock locally called White 
Limestone (indurated chalk). This rock occurs all round the coast 
of Antrim: it is used mainly for lime; but sometimes it is used 
for dressing. It is too full of joints to look well, or to stand frost 
(W. Gray). 


ARMAGH. 
CARBONIFEROUS. 


Glasslough.—Used in the spire of Corporation-street and Carlisle 
Churches, Belfast; also in Robinson Villa, Cultra, Co. Down. 
““Of a good high colour; works freely; durable” (W. Gray). 


t 


CAVAN. 
CARBONIFEROUS. 


Rocks.—One mile from Cavan.—Surface rock; no regular 
quarry. Used in the Masonic Hall, Cavan (built 1885), for wall- 
ing. The stone seems to be durable, and works freely. The 
dressings are of sandstone from Lisnaskea, Co. Fermanagh. 


490 Scientific Proceedings, Royal Dublin Society. 


Ardhill.—Six miles south-east of Cavan.—School; built 1886. 
The local stone only used for walling and rubble; those for the 
dressings being procured from Crossdrum, Co. Meath. 

Mount Nugent.—Drumrora School; built 1886. The stone is 
only suitable for walling, and is said to be durable. The dress- 
ings from Ross, Co. Meath. 


CLARE. 
CARBONIFEROUS. - 


Bushy Park.—Ennis Courthouse, in entire building ; ; in Prison, 
for dressed work. Light colour; worked easily. 

Rosslevin.—Ennis Prison, used with the Bushy Park stone. 
Dark colour. 

Klfenora.—Knnistymon Church. Dark colour; worked hard 
(W. D. Williams). 


CORK. 
CARBONIFEROUS. 


Carriglass and Conna.—Carriglass School and Conna Glebe- 
house. Used for the rubble-work and quoins; but it is of 
too small dimensions for the sills of windows and doors (A. 7. 
Williams). 

Ballydaniel or Pothouse.—Ballydaniel Schoolhouse and Resi- 
dence solely built of these stones. The stone has also been largely 
used for heavy railway works, but is not suitable for sills, or in 
general for ordinary building purposes (A. 7. Williams). 

Cloyne.—School. The local stone runs in small sizes; and for 
' large scantlings the Carrickacrump stone is used. 

Carrickacrump.—Yor the description of this well-known stone, 
see page 416. Mr. Williams points out that it has been exten- 
sively used in the Cork harbour and Haulbowline works. 

Ballintemple. —School. This stone is another that is well- 
known, having been made historical by Macaulay (page 416). 

Ballintubber (Kanturk).—Used in the dressings for the Church, 
Killarney, Co. Kerry. Light-coloured; a very superior stone. 

Mitchelstown.— Between the town and the workhouse. A 
marble; grey; a good working stone (J. Newstead). 


Kinanan—On Marbles and Limestones. 491 


Boreenmanagh and Haulbowline Island, near Cork.—Reddish ; 
slaty character ; formerly used to some extent for chimney-pieces. 
About one mile south-west of Cork there is a vein about three or 
four inches thick in the ordinary limestone. 

Ballyclough, near Mallow.—Reddish; hard; slaty character; 
suitable for flagging ; formerly used a little for chimney-pieces. 


DONEGAL. 


MetamorpnHic CAMBRIAN ? on ARENIG? 


Dunlevey.—A marble, used in Dunlevey Church for dressing, 
walling, and rubble. In Glenalla Church, near Rathmullen, for 
dressed work in the windows, doors, and buttresses. Capable of 
good and fine work ; a superior stone, but cannot be raised in large 
sizes. 

Ballymon.—Sheephaven Coastguard Station. An inferior 
marble, used in the quoins, piers, and sills; very hard to work; 
very durable (J. Cockburn.) 

Gienree (“‘Cooskeagh Quarry ’’). South-west of Carrigart.— 
Whitish, grey-clouded, and greyish. A marble. Free and 
kind; durable; a good stone for inside and outside work. Used 
for the dressing of the Millford Union Workhouse ; dressing but- 
tresses and pulpit Glenalla Church; chimney-pieces Glenalla 
House; inside work Carrigart Roman Catholic Church. The 
fonts at Ramelton and Glenalla Churches were cut out of one 
block (J. I‘ Fadden). 

Barnes Lower (O’Donell’s Quarry). North-west of Kilma- 
crenan.—Greyish-blue; durable; a good stone for hammered, 
dressed, and rubble work. Quarry opened in 1846, when building 
Kilmacrenan New Church; since has only been worked for lime- 
burning (J. IM‘ Fadden). 

Carn Lower. North-east of Rathmelton.—Limestone; hy- 
draulic. 

[In this county, more than any other in Ireland, are the metamorphous limestones 
capable of being used for cut-stone purposes. See p. 417] 


CARBONIFEROUS. 


Ballyshannon (various places in vicinity).—Convent of Mercy, 
Ballyshannon. Hand-punched for facing and quoins; it works. 


492 Scientific Proceedings, Royal Dublin Society. 


freely and well. Also for internal work, with sandstone, in the 
Belfast Banking Co. Buildings (J. Cockburn). 


DUBLIN. 
CARBONIFEROUS. 


Milverton (Skerries).—Balbriggan Coastguard Station. Used 
on the base of the octagon tower, sills, and dressings; also in 
Rockabill Lighthouse. A hard limestone, rather stiff to work (see 
description, p. 420). 

Howth.—Grey ; magnesian; makes good hydraulic lime. 


GALWAY. 
CARBONIFEROUS. 


Angliham.—Queen’s College; Model School; Parapet of the 
Tower of St. Nicholas’ Church, all in town of Galway. Used for 
the sills, quoins, and dressings ; works freely, and found durable. 

[In this neighbourhood (Angliham), as previously mentioned (p. 425), there are 
acres of most superior stone. As these lie in nearly horizontal beds, they ought to be 
invaluable, if worked on the American principle of cutting them by machinery in situ 
in the quarries. An enterprising Company might ‘‘run a big thing in stones’’ from 
the Port of Galway for the English market, more especially as the freights from all 
the west coast of Ireland are low, most vessels having to leave it in ballast. 


KERRY. 
CARBONIFEROUS. 


Livnaw.—Dominican Church, Tralee. A marble, close-grained, 
uniform texture, and capable of a high polish. Used for the 
moulded bases and the columns of nave. 

Bailylaggan (near Tralee).—St. John’s Church, Tralee. Used 

for the dressing in the new addition. Light-coloured, superior 
stone; free, durable; works out in large blocks. 

Castleisland.—Roman Catholic Church. A marble capable of 
a high polish. Colour, light red. Used in the piers of the 
chancel. 


KILKENNY. 


CARBONIFEROUS. 


Kilkenny (vicinity of).—Used in the Kilkenny Model School, 
Lunatic Asylum, Agricultural Museum, and other public buildings, 


Kinanan—On Marbles and Limestones. 493 


for punched, chiselled, or moulded work. The stone is of a good 
grey colour; hard and durable; it flies well before the punch and 
chisels to a good surface, but not so fine as that of the Ardbreccan 
stone, or of that of Sheephouse, Co. Meath (If. Mellen). 

Ballykilboy and Strangs Mills— Waterford City, in the Govern- 
ment offices and public buildings. Granite and limestone dressings 
in both buildings worked freely (W. D. Williams). 


LEITRIM. 


CARBONIFEROUS. 


Carrick Klevy Station.—Carrick-on-Shannon Roman Catholic 
Church. Durable; squares well under the hammer. For chiselled 
work the stones were brought from Lanesborough and Creeve, Co. 
Longford. 


LONGFORD. 
CARBONIFEROUS. 


Creeve. Near Longford.—Used for dressings in the Roman 
Catholic Church, Carrick-on-Shannon ; in the Bishop’s Palace, 
and in the Asylum, Mullingar ; in the Crummy School, half-way 
between Carrick and Ballinamore, Co. Leitrim; and in Cloon- 
morris School, between Dromod and Newtown Forbes. 

Lanesborough.-—For dressings used in the Ballymahon School ; 
in the Roman Catholic Church, Carrick-on-Shannon ; and in the 
new Convent, Sligo. 

Ballymahon.—Very brittle; hard ; difficult to work; durable. 
Used for rubble in the National School. 


MAYO. 
CARBONIFEROUS. 


Moyne (Ballina).—Used for dressing and walling in the Roman 
Catholic Cathedral, Ballina, and in various buildings, both modern 
and ancient, as given in the descriptions of the Mayo quarries. 
“Works freely ; found durable; but weathers of a bad colour” 
(R. Cockrane). 


494 Scientific Proceedings, Royal Dublin Society. 


MEATH. 
CARBONIFEROUS. 


Ballymadrin. Three miles from Ratoath.—Is fairly good and 
durable. Used in the walling of Ratoath Dispensary ; built in 
1886. The stones for the dressing procured from Crossdrum. 

Stirrupstown. Near Crosskeys.—Hard, and only fit for scab- 
bled work. Used for walling in the neighbouring Constabulary 
Barrack. The stones for the dressings were procured from Cross- 
drum. 

Ross.—This well-known stone is very generally used for cut- 
stone purposes in various parts of Ireland (see description, p. 436). 

Crossdrum.—Another well-known stone (see description, p. 436). 


QUEEN’S CO. 
CARBONIFEROUS, 


Stradbally and Bailullen.— Maryborough Churches, Prison, and 
Asylum; Mountmellick Churches and Convent. In Abbeyleix 
Churches, with Slieve Bloom sandstone; both being used in the 
dressings (W. D. Williams). 


ROSCOMMON. 
CARBONIFEROUS. 


Carrowroe. Two miles from Roscommon.— Works pretty 
freely ; is durable. Used for walling and rubble in the new Con- 
vent, Roscommon. The stones for the cut-work were procured 
from Lanesborough, Co. Longford. 


SLIGO. 
CARBONIFEROUS. 


Ballysodare.—A. uniform stone; works well into mullions 
and tracery, and is durable. Used in St. John’s Church, Sligo, 
in the new east window, vestry-room, and organ-chamber (R. 
Cochrane), and in the Roman Catholic Church and Presbytery for 
both dressed work and rubble. 


KinaHnan—On Marbles and Limestones. 495 


Scarden. Three miles from Sligo.— Hard and flinty ; durable. 
Used for rubble and the pitched faces of the walls in the Town 
Hall, Sligo. The dressings are of sandstone, from Mount Charles, 
Co. Donegal. 

Carrowroe. Two miles from Sligo.—Works pretty freely ; is 
durable. Used for walling and rubble in the new Convent, 
Sligo; the stones for the dressing being procured from Lanes- 


borough, Co. Longford. 


[In the hills to the north-east of this county there ought to be excellent limestone 
for all dressed purposes; as, however, there are no quarries opened, they send to great 
distances for stones for dressing and other cut works. | 


TIPPERARY. 
CARBONIFEROUS. 


Ballinillard.—Tipperary Town Churches. Appears to have 
worked freely. 


TYRONE. 
-CARBONIFEROUS. 


Omagh. YVicinity.—Used for rubble in the Military Barracks. 
The sandstone used for quoins and dressing is of an inferior qua- 
lity, being the stone known as the “‘ Red Beds” from the Gortna- 
glush quarry, near Duncannon, which is easily worked, but is not 
durable (J. Cockburn). 


WATERFORD. 
CARBONIFEROUS. 


Whitechwrch.—As dressings in the Churches, Dungarvan, and 
Lismore Castle. 

Shorough.—Lismore Roman Catholic Church, with sandstone 
dressings (W. D. Williams). 


SCIEN. PROC. R.D,S.—VOL. Y., PT. VI. oL 


496 Scientific Proceedings, Royal Dublin Society. 


WESTMEATH. 
CARBONIFEROUS. 


Cullion. Two miles from Mullingar.—Rather hard and 
splintery for chiselled work ; very durable. Used in the Bishop’s 
Palace, and in the Asylum, Mullingar, for walling, rubble, and 
part of the dressed work ; but in both buildings most of the stones 
for cut purposes were procured either from Creeve (Co. Longford), 
or Ross (Co. Meath). 


soa] 


XLVITI.—ON THE LIASSIC FOSSILS OF M‘CLINTOCK’S 
EXPEDITION. By REV. DR. HAUGHTON, F.R.58. 


[Read, January 19, 1887.] 


Tue following correspondence throws further light on the fossils 
found by Sir Leopold M‘Clintock at Wilkie Point, Prince Patrick’s 
Land [lat. 76° 20°N.; long. 117° 20’ W.], and described by mein 
this Journal (vol. 1., pl. ix.) 

The letters sufficiently explain themselves, bearing in mind 
that I had originally stated my opinion that the fossils were of 
Jurassic age (probably Liassic.)—S. H. 


N.B.—These fossils were presented by Sir Leopold M‘Clintock 
to the Museum of the Royal Dublin Society, and can now be seen 
in the Science and Art Museum, Dublin. 


“‘GronogicaL AND Naturat History Survey, 


‘¢ Musbum AND OFFICE, SUSSEX-STREET, OTTAWA, 
“5th November, 1886. 


‘‘ Dear Srr—In endeavouring to work up a small general Geologi- 
cal Map of the Northern part of the American Continent, which may be 
published in connection with our reports, I have had frequent occasion to 
refer to your Appendix to M‘Clintock’s Voyage, which gives, I think, 
practically all the facts available for the northern portion of the Arctic 
Archipelago. 

‘“T have not access to the earlier Papers in the Journal of the Royal 
Dublin Society, but presume the Appendix (edition of 1860) may contain 
a sufficient reswmé of the whole. 

‘The point on which I take the liberty of addressing you, particularly 
at the present moment, is the character of the fossils described as Liassic, 
and figured in the Journal of the Royal Dublin Society, vol. i., pl. ix. 

‘Ts it possible, in your opinion, that these fossils may indicate a 
horizon the same with that of the so-called ‘ Alpine Trias’ of the western 
part of North America? From the occurrence of a Monotis, western 
analogies would rather tend to this view of the case, which, however, the 
fossils themselves may be sufficient to disprove. If not troubling you 


498 Scientific Proceedings, Royal Dublin Society. 


too much, I should be glad to have the benefit of your views on this sub- 
ject. The Fauna of the ‘Alpine Trias’—which occurs high up on the 
west coast—is well illustrated in Exploration of 40th Parallel, vol. iv., 
plates 10 & 11, and in Palzontology of California, vol. i., plates 3-6. 


“Yours truly, 
‘“‘GEORGE M. DAWSON. 
“¢ Rev. Pror. 8. Haucuton, F.R.S. 


‘¢ PRAGUE, 
“31st December, 1886. 


‘My pear Barr—You must excuse me that I did not answer your 
kind letter earlier, but it had somehow miscarried, so that I received it 
about a fortnight later than the book. 

‘The fossils about which you wish to have my opinion have aroused 
curiosity already on several sides, and about a year ago Professor 
Neumayer, of Vienna, sent me a number of plaster casts of the species, 
taken from the originals at Dublin, to ask my opinion about them. 

‘As far as I can judge the matter, it seems to me that there cannot 
be much doubt that Ammonites M‘Clintocki is a Jurassic species, but 
rather of middle Jurassic than of Liassic affinities. This opinion has also 
been expressed by Neumayer in the Denksch. d. Kais. Acad. der 
Wissensch., Vienna, vol. i., Die Geographische Verbreitung der Jura 
Formation, p. (141), 1885, where the species is redescribed and figured. 

‘The Avicula that has also been found at the same localities might be 
Triassic, but just as well it might be Jurassic, and there can be drawn no 
conclusion from that species. So, on the whole, the probability remains 
that in these high latitudes Jurassic beds are exposed. 

‘The Triassic species described by White from Idaho, in his Contri- 
. butions to Paleontology, and later on in the 40th Parallel Report, are 
quite different things, and only the Avicula show at all any similarity. 
Such a similarity is, however, of no value whatever. 


“‘Very sincerely yours, 
“W. WAAGEN. 
“V. Batt, M.A., F.R.S.” 


[ 499 ] 


XLIX.—NOTE ON SUBMERGED PEAT MOSSES AND TREES 
IN CERTAIN LAKES IN CONNAUGHT. By A. B. 
WYNNE, F.G.S. 


[ Read, March 28, 1887.] 


THE object of this communication is to place before the Society a 
few observations upon what might be regarded as evidences of 
relative changes in the level or superficial distribution of land and 
water in the regions referred to. 

There are, doubtless, several cases besides those to which I 
shall refer, wherein peat bogs, with trees of a former period, are to 
be found permanently submerged in various parts of the country, 
and in present conditions totally different from those under which 
these trees and growths flourished. It will be sufficient, however, 
to take the instances of the basin of Lough Arrow, a few miles 
from Boyle, and of the River Garwogue, connected with and 

running from Lough Gill, through the town of Sligo. 
_ As far as regards present circumstances, the basins of both of 

these lakes are extensively encumbered with “ drift,” and the water 
is retained, in both cases, practically in rock basins: that is to say, 
river action has denuded the drift in the direction of outflow, and 
the surplus water escapes over beds of the solid carboniferous lime- 
stone of that country, lying in a nearly horizontal position, or 
undulating at low angles. In both cases the margin of the water 
is formed here or there by rock, drift, or the ordinary bogs of the 
country, the latter indicating, perhaps, a formerly wider extension 
of wet, swampy ground around these lakes or of their own proper 
areas. 

The River Garwogue leaves Lough Gill as a broad, sluggish 
stream, until its rock-bar is reached at Ardachowen. Thereafter 
the stream becomes more rapid, falling some twenty feet in the 
short distance between Ardachowen and the tideway, which enters 
the town of Sligo as far as the Victoria Bridge. ‘I'he last reach of 
the comparatively still water, just above Ardachowen—one of the 
most beautiful parts of that picturesque locality—is underlaid from 
side to side by peat, with numerous trunks of trees. It is plain 


SCIEN. PROC. R.D.S.—VOL. V., PT. VII. 2M 


500 Scientific Proceedings, Royal Dublin Society. 


that the water here could never have escaped at a lower level than 
that of its present retaining rock-bar, so as to permit of the sunken 
forest trees having flourished in the air, without the supposition of 
earth movements having taken place since the peat and trees occu- 
pied the subaerial surface, movements which had considerably 
altered the position of the ground to be drained with regard to 
previously existing levels. 

Further seaward, along Sligo Bay, there are indications, in 
raised beaches, that an upward movement of the land took place ; 
and I found, many years ago, shells of the common sea mussel in 
a sand-pit, not far from the old coach-road between Sligo and 
Ballysodare, upon part of the high drift-covered ground lying 
between Lough Gill and Ballysodare Bay. In these cases the 
indication is of an elevation in recent times, which might here or 
there pond back the terrestrial water, but which must have had 
regions of singularly local intensity, if it can be at all supposed to 
have caused limited land spaces to become permanently submerged, 
as in the case near Ardachowen, on the Sligo river. 

Turning now to Lough Arrow, near Boyle, we find this to be 
a large lake, with irregular outline, four and a-half miles in length, 
by a mile to two and a-half miles in breadth, bordered by hog- 
backed hills of drift near its margin, similar hills forming islands 
within it, while it is surrounded by nearer, or more remote, moun- 
tainous elevations, suchas the Geevah Hills, formed of coal-measures, 
on one side, or the carboniferous limestone elevations of Knockna- 
horna and Kesh, on the other, or the termination of the pre-carbon- 
iferous Curlew Mountains towards the upper, or Boyle end of the lake. 
The lake itself is peculiar in having no rivers to supply it beyond 
the little brook from the Curlews, which empties itself into it at 
Ballinafad. The lake water is clear, and is probably largely sup- 
plied by springs, seeing that a considerable stream issues from the 
lake, passing over a rock barrier near where it starts, at Annagh 
or Ballyrush, and eventually reaching the sea at Ballysodare. 
Another peculiarity is that this large lake is at one point sepa- 
rated by a distance of only a few hundred yards from Lough Key, 
one of the lakes of the basin of the Shannon, with which that of 
Lough Arrow has no connexion. 

The shores of Lough Arrow, where not formed of drift, are im 
various places composed of peat, locally known as “ ‘The Black 


WrynneE—On Submerged Peat Mosses and Trees. 501 


Banks,” particularly around the deeply-indented bay called Lough 
Brick, and at the lower end of the lake about Ballyrush, Annagh, 
and Castlebaldwin. Where this is the case the bottom of the lake 
is often also formed of peat with trees, while in other places huge 
masses of the local rocks washed out of the drift, like that called 
the “Rock of Muck,” on the Annaghcloy shore, may be seen, 
scattered over the bottom, through the clear water, when this is 
calm. Under similar circumstances, off the point of Aughanah, 
on the property of; Colonel Ffolliott, where the almost horizontal 
limestone comes to the surface of the lake, at the shoal called the 
“ Quarries,” or the “ Flag of Aughanah,” one can see, down be- 
neath the lowest level to which the water ever falls, the stools 
and stumps of large trees, so thickly accumulated in places, that 
when in the little strait between ‘‘ The Slab” and the point, boat- 
men exert more than usual caution to avoid “snags.’’ Most of the 
trees appear to be in their position of growth, with, in some cases, 
but little, if anything, intervening between them and the limestone 
slab on which they¢rest. 

Here again the case recurs that the lake could scarcely have 
stood at a lower level while its escape lay in the present direction, 
on account of its retaining rock barrier; and the conditions which 
would have placed these trees in their natural subaerial position, 
would require either the occurrence of earth movements of subse- 
quent date, or such a balance between the supply of lake water 
and its exhaustion by means of evaporation, that the water should 
be maintained at a lower level than at present, when of course the 
lake could have had no river outlet at all. : 

I have been acquainted with both of these lakes since child- 
hood, and I have repeatedly visited Lough Arrow at the season of 
the Ephemeral June Carnival of Salmo ferox. Lough Brick, of 
which I have spoken, was, within my memory, almost a small 
separate lake, partly surrounded, and nearly divided from Lough 
Arrow, by bog banks. Through a gap in these banks a boat could 
just pass; but the banks have since been almost entirely washed 
away—one islet?remaining near where the gap was, on both sides 
of which boats can pass freely now. 

On Captain Gethin’s property at Ballindoon, towards the other 
end of the lake, there is a small recess in the boggy bank of the 
lake, called “‘Poolnaperches.” Here a projecting promentory of 


2M 2 


902 Scientific Proceedings, Royal Dublin Society. 


peat bore some trees of considerable size. The promontory became 
an islet, and this has been washed away by the waves of the lake, 
on which I have seen a heavy sea often rise as rapidly as has been 
noticed in many other lakes all over the world (from Lough Gill 
to the Lake of Kashmir, or in the opposite direction). 

Now, taking this wasting by wave action of the boggy margin 
of the lake into consideration, in discussing the problem of the 
sunken trees with Captain Gethin’s steward (Sergeant Ross), whilst 
fishing off ‘Poolnaperches,” one day last summer, he seemed to 
me to hit upon an explanation which would account most satisfac- 
torily for the submerged forest trees of Aughenagh Point, and 
may be capable of a wider application in many similar cases of 
such submergence. We both observed that the stools of the old, 
as well as those of the modern, trees in these bogs, spreading their 
roots horizontally, retained their position thus until the boggy 
ground they grew in had been almost entirely removed. Deprived 
of the leverage which their stems—previously broken off—would 
have given, they had less to disarrange their natural pose; and 
thus, when some storm of greater force than usual acted, the 
retaining roots snapped or drew, and each water-logged mass sub- | 
sided to the bottom, settling upon its broadest surface, still in its 
natural position of growth; so that afterwards, looking down 
through the water, the trees would appear to have grown where 
seen, though entirely beneath the water of the lake, and associated 
in cases with a recomposed peaty deposit. 

As to the extent to which this action may have affected the 
shores of Lough Arrow, Sergeant Ross further stated that, under 
a particular effect of light, upon a stormy day, he had seen from 
Ballindoon House, which stands high upon one of the drift hills, 
a long, dark channel, reaching sinuously from the river at Bally- 
rush through the middle of the lake, between Ballindoon and 
Bell’s Island opposite. The lake, at its lower end, from one side 
to the other across this channel, appears to have both boggy banks 
and a boggy bottom. Hence it is not improbable the channel he 
saw may have marked a former bed of the river, before the bog on 
each side had been eroded away; and the definition of this channel 
may have been aided by the storm having disturbed the marly 
substratum that not unfrequently underlies our Irish bogs. 

I am not quite prepared to say how far these observations may 


Wrynne—On Submerged Peat Mosses and Trees. 3038 


account for the supposed submergence of peat mosses, with forest 
trees, in all cases in inland lakes of the West of Ireland; but the 
explanation seems to be capable of affording a satisfactory solution 
of the question regarding Lough Arrow and the Sligo river, 
without making any unnecessary overdrafts upon possibilities as 
to local or considerable earth movements at very recent periods, 
and even though it may deprive the subject of a certain halo of 
mystery—if I may be allowed to adapt to this subject the well- 
known lines of our national Bard—it would supply some answer 
to an inquiry frequently made: 


‘¢ When on these waters the fisherman strays, 
Or becalmed in his boat reclining, 
He sees the old forests of other days 
In the wave beneath him shining.”’ 


eT 


L.—LISBELLAW CONGLOMERATE, CO. FERMANAGH, AND 
CHESIL BANK, DORSETSHIRE. By G. H. KINAHAN, 
M.R.I.A., Erc. (Plate XII.) 


[Read, March 23, 1887.] 


Ir would appear that the process of formation, and the agents at 
work during the accumulation of the ‘ Lisbellaw Conglomerate,” 
have been a puzzle to those who have examined it, or rather to 
those who have published the results of their examination. 

It ought not, however, to be so hard to understand, as similar 
accumulations are due, not only to the artificial groynes erected on 
beach-lines, but also to natural groynes, as they occur on the south- 
east coast of Ireland. As the accumulations due to groynes, arti- 
ficial or natural, seem not to have been studied by those observers, 
it may possibly be allowable to give an epitome of the effects due 
to them, and their general characters. 

In general, artificial groynes are placed as near together as to 
form a continuous permanent shingle beach; and if they are ju- 
diciously erected, that is, raised plank by plank as they fill, much 
in connexion with the present inquiry cannot be learned from 
them. 

But in many places on coast-lines more or less isolated groynes 
have been put down to project individual portions of a coast-line, 
as is the case in places along the coast of Waterford. From such 
individual groynes we learn, if we follow the “ flow-tide” stream 
towards the groyne, that the accumulations gradually become wider, 
and, in general, the materials coarser, till at the groyne there is a 
“massive shingle accumulation. This seems to be invariably the 
case on the coast of Waterford, and also in various places on the 
English coast; but in other places, as presently mentioned, where 
the tidal-drift is solely a fine sand, the accumulation, although it 
will increase in bulk, yet the sizes of the materials will not do so. 
On the down-stream side of a groyne, like those on the beaches of 
Waterford, the accumulations will be small in dimension, and the 
material composing them much finer than those on the up-stream 
side. 


Kinanan—Lisbellaw Conglomerate, Co. Fermanagh, &c. 505 


On the coast of south-east Ireland (Co. Wexford), as the normal 
drift of the county for a large part is fine sand, the drift due to 
the “ flow-tide ” current is in general of a similar character; and 
the big accumulations on the up-stream side of the groyne are in 
general sand. This, however, is not the case in the beach to the 
north of the Blackwater. Here, to the north-east, Cahore Point 
acts as a groyne, and south-west of it, at the head of the current 
from the Blackwater, there is a shingle beach. This is some- 
what like the “ Lisbellaw Conglomerate,” gradually down-stream 
becoming coarser and larger, but dying out before the extremity 
or point of groyne is reached. The reason for the ending of a 
shingle beach before it quite reaches the natural groynes is due 
to the “on-shore, or half counter-tide currents.” As this has 
been previously explained in different Papers already published, 
it is unnecessary to again repeat it. 

There is, however, a much more parallel accumulation in that 
of the Chesil Bank, Dorsetshire; although what is now taking 
place at the latter is on a much larger scale than the work done 
in Silurian times at Lisbellaw. 

The Chesil Bank travels eastward along the shore of Lyme 
Bay, with the “flow-tide” current accelerated by the prevailing 
winds from the westward, to be stopped by the natural groyne— 
Portland Bill. If this beach is followed from the west eastward, 
the accumulation gradually increases in size, and also in the di- 
mensions of the materials, till eventually it forms a mass of more 
or less coarse material to the westward of the Bill. But, on the 
other hand, in Weymouth Bay, eastward of The Bill, the accumu- 
lation is at a minimum, and of fine materials. 

As may be seen in the accompanying diagrammatic plan (Plate 
XIT.), the relation between the adjuncts of the Chesil Bank and, on 
a smaller scale, those in connexion with the “ Lisbellaw Conglo- 
merate,” is very similar, except that while the “ flow-tide” cur- 
rent in the first set from the west eastward, that in the Silurian 
sea must have ran south-westward. 

To the north-eastward of Lisbellaw, in Silurian times, there 
was a shore-line trending north-eastward, and immediately west 
of the village a spit of Ordovician land, somewhat like the Port- 
land Bill, while westward of this spit was a bay that may be 
compared with Weymouth Bay. 


506 Scientific Proceedings, Royal Dublin Society. 


The Silurian beach that accumulated along the north-east and 
south-west shore-line has similar characters to that on the north 
shore of Lyme Bay; that immediately west of the north end of 
Lough Eyes, being of small dimensions and finer materials, while, 
as it is followed south-west, to Lisbellaw, it increases in bulk and 
the size of the materials. This beach, as it is now much over- 
lapped by the newer carboniferous rock, cannot be entirely seen ; 
but it seems to end suddenly before the point of the Ordovician 
land is reached, while westward of that spit of land the Silurian 
rocks are of quite a different character, being sandstones and shales. 
Thus there is more or less a very complete similitude between the 
two. As in each case there is a breach gradually getting larger 
and coarser, till it nearly reaches the point of the groyne, where 
it ends; while at the other side of the groyne the accumulations 
are at a minimum, and of a much finer character. 


507 


LI.—IRISH ARENACEOUS ROCKS—SANDS, SANDSTONES, 


GRITS, CONGLOMERATES, QUARTZ-ROCKS, AND 
QUARTZYTES. By G. H. KINAHAN, M.R.I.A., Ere. 


InTRoDvcTION, 


[Read, March 23, 1887. ] 


CONTENTS. 


GroLoGicaL ErirroME :— 


Cambrian and Arenig—Ordovician—Llandovery or Mayhill Sandstone— 
Silurian and Devonian—Carboniferous—Permian—Triassic—J urassic 
—Cretaceous—Tertiary—Drift—Sand and Grayvel—Glass, 


Antrim, 


Armagh, . 


Carlow, 
Cavan, 
Clare, 
Cork, 
Donegal, . 


Down, 
Dublin, 
Fermanagh, 
Galway, . 
Kerry, 


Kildare, 


County Historizs :— 


Arenig or Ordovician, Silurian, Carboniferous, Triassic, 
Cretaceous, &c.; Flints, Agates, Sand and Gravel, 
Glass, . : . 5 : é ° 


Ordovician, Carboniferous, Permian, Triassic, Sand and 
Gravel, . . 3 3 3 : 6 : 6 


Carboniferous, Sand and Gravel, 

Ordovician, Carboniferous, Sand and Gravel, 
Ordovician, Carboniferous, Sand and Gravel, 

Silurian and Devonian, Carboniferous, Sand and Gravel, 


Cambrian and Arenig, Ordovician and Llandovery, 
Carboniferous, Sand and Gravel, . 6 C 


Ordovician, Carboniferous, Triassic, Sand and Gravel, . 
Carboniferous, Buildings, Sand and Gravel, Glass, 9 


Ordovician, Silurian, Carboniferous, Fermanagh Series, 
Coal Measures, Enniskillen Quarries, Sand and 
Gravel, 

Cambrian, Arenig, and Ordovician; Silurian, Carbon- 
iferous, Sand and Gravel, 


Ordovician, Llandovery, Devonian and Carboniferous, 
Coal Measures, Sand and Gravel, Glass, 


Carboniferous, Sand and Gravel, . 


508 


Kithenny, « 
King’s Co., 


Leitrim, . 


Limerich, . 


Londonderry, 


Longford, . 
Louth, 


Mayo, : 


Meath, . 
Monaghan, 


Queen’s Co., 


Roscommon, 


Sligo, 


Tipperary, 


Tyrone, . 


Waterford, 


Westmeath, 
Wexford, « 
Wicklow, . 


Donegal Co., 
Dublin Co., 


Scientific Proceedings, Royal Dublin Society. 


County Historres—continued. 


Ordovician, Carboniferous, Flags, Sand and Gravel, « 
Carboniferous, Sand and Gravel, . 6 0 


Arenig or Cambrian, Ordovician, Silurian, Carbonifer- 
ous, Sand and Gravel, . . 3 3 ¢ : 


Ordcvician, Carboniferous, Sand and Gravel, 5 : 


Ordovician, Silurian, Carboniferous, Triassic, Jurassic, 
Cretaceous, Flints and Agates, Sand and Gravel, . 


Ordovician, Carboniferous, Sand and Gravel, : : 
Ordovician, Carboniferous, Sand and Gravel, 9 4 


Cambrian or Arenig, Ordovician, Silurian, Carbonifer- 
ous, Sand and Gravel, . : : 


Ordovician, Carboniferous, Triassic, Sand and Gravel, . 


Ordovician, Carboniferous, Fermanagh Series, Sand and 
Gravel, . 5 . : 4 5 : : 5 


Lower Carboniferous Sandstone, Coal Measures, Sand 
and Gravel, . 9 . 0 3 : ° 


Ordovician, Silurian, Lower Carboniferous Sandstone, 
Coal Measures, Sand and Gravel, . Z : 5 


Cambrian, Arenig, and Ordovician, Silurian, Carbonifer- 
ous, Lower Carboniferous Sandstone, Coal Measures, 
Sand and Gravel, . , 6 6 < 


Ordovician, Devonian, Carboniferous, Lower Carbon- 
iferous Sandstone, Coal Measures, Sand and Gravel, 


Ordovician, Silurian, Calp, Ulster type Calp, North of 
Coalisland; Fermanagh Series, Coal Measures, Sand 
and Gravel, . 


Ordovician, Devonian, and Carboniferous, Sand and 
Gravel, Glass, : 4 0 : 0 


Sandstones, Sand and Gravel, Fi é 5 2 
Cambrian, Ordovician, Carboniferous, Sand and Gravel, 


Cambrian, Ordovician, Sand and Gravel, Glass, 


Nores ADDED IN THE PRESS :— 


PAGE 
572 


576 


578 
580 


681 
584 
585 


586 
591 


592 


594 


596 


599 


600 


604 


610 
614 
615 
617 


619 
619 


Kinanan—On Irish Arenaceous Rocks. 509: 


INTRODUCTION. 


A stupy of the history of the Irish sandstone rocks is interesting, 
they seemingly having been the favourites with the early builders. 
The primitive inhabitants of the country appear nearly invariably 
to have utilized the hardest stone nearest at hand, so that in many 
places they used the granite erratics; but in such places where 
there were both granite and sandstone erratics, they seem to have 
chosen the latter; while, if the rock had to be quarried, it was 
nearly always the sandstone that was selected. 

After stone with mortar was introduced, at first sandstone 
still seems to have had the preference in the districts in which it 
occurred, except in a few places where there were good slate-rocks ; 
as these, in certain localities, were extensively used, and are still 
used, for architectural purposes. This, however, will be more par- 
ticularly mentioned in a subsequent paper on Slates and Clays. It 
may, however, be here mentioned that some of these slate-rocks, 
although producing good and durable work, were not at the same 
time capable of giving the fine and embellished cut-work to be 
found in the granite, limestone, and sandstone structures. 

Later on, as has been pointed out by Kane, Wilkinson, and 
others, the sandstone was superseded by limestone, the latter rock 
having been often carried for great distances into the sandstone 
areas. This probably was due ina great measure to the workmen, 
who had a preference for the stone to which they were accustomed. 
Various examples in modern time in support of such a supposition 
are on record. When the Scotch workmen were building Muckross 
Abbey, Killarney, about forty years ago, they ignored the ex- 
cellent limestone of the neighbourhood, and imported sandstone 
from Chester, that being the nearest place where they could get 
sandstone similar to that with which they were accustomed; and 
in different places, the engineers of the Ballast Board, when 
building lighthouses, have brought Dublin granite to the dif- 
fferent localities. This may be seen, besides, in various other 
places, at the West Sound into Bearhaven, Co. Cork—a locality 
famous for its good sandstone. Kylemore Castle, Co. Galway, 
was contracted to be faced with granite, and although the locality 


010 Scientific Proceedings, Royal Dublin Society. 


is on the edge of the great granite tract of Galway, yet the con- 
tractor elected to bring the stone from Bullock, Co. Dublin—a stone 
he was accustomed to. We find also the same thing in earlier 
times. ‘The Normans, for dressing and other cut-stone purposes in 
their castles and cathedrals, brought from their native country, Caen- 
stone into England, while their descendants, the Anglo-Normans, 
did the same in regard to Ireland. ° 


[It seems to be the general opinion that there is no home stone at present in the 
market equal to the Caenstone for fine inside work; but during the late restoration of 
Christ Church Cathedral, Dublin, some of the old cut-stones (a.p., 1008) were found, 
which the architect seems to have insisted were ‘‘Caenstone.’’? But the builder (Mr. 
Sharpe) was not of this opinion, and, after considerable research, he was able to prove 
that the stone was procured ina once famous quarry at Eyebridge (?), about twelve miles 
from Glastonbury, Somersetshire. He visited the place, and the stones seem to have 
been brought from the quarries by a canal, the remains of which can be traced. From 
Mr. Sharpe’s practical knowledge he is convinced that this stone was used in Mellifont 
Abbey, Co. Louth; St. Mary’s Abbey, Dublin; and St. Kevin of Glendalough, Co. 
Wicklow—stones which in general are supposed to be Caen-stone. Mr. Woodward, 
the author of the Geology of England, in reply to inquiries, states :—‘‘ The stone 
you inquire about must be the Doultery stone, east of Shepton-Mallet ; used largely 
in the construction of Wells’ Cathedral and Glastonbury Abbey. ] 


But’ the pre-Anglo-Norman builders in Ireland, as already 
mentioned, as also many of the early Anglo-Normans, used the 
native sandstone. It is conspicuous in different places, as here- 
after mentioned, that although the local sandstone used in building 
of the earlier structures was good, yet all the later structures are 
built of limestone brought from a greater or less distance. 

Other reasons for the introduction of limestone may have been 
that the builders early understood the crushing stones were capable 
of bearing,' and were aware that if a column in a building was to 
be massive, they might use sandstone; while if the column had 
to be slender, and at the same time support an equal weight, 
limestone was preferable. This is illustrated, as pointed out by 
Wyley, in the small limestone columns of Jerpoint Abbey, Co. 
Kalkenny. 

They also must early have learned that limestone could be 
more finely, more easily, and more cheaply worked than the 


1 Yet Wilkinson specially points out that some builders had no such knowledge, 
and illustrates instances in which buildings had failed through the want of knowledge 
as to the crushing the stone would bear. 


KinanwAan—On Irish Avenaceous Rocks. 511 


ordinary sandstone of the country, many of the latter requiring 
the tools to be frequently sharpened. 

Although the strength of the limestone, and the facility by 
which it could be worked, may have led to a preference for it, it 
should also be remembered, that as the country became occupied by 
foreigners, the chief centre of the population—that is the towns— 
were principally in the plains, or the valleys, on the limestone areas, 
and the artificers, becoming cunning in the working of limestone, 
preferred to use it, even when they had to transport it a considerable 
distance. In many places, however, they had water-carriage ; that 
made the transport comparatively easy and cheap. 

Or the use of limestone may have been due to fashion. At the 
present day many rich men will only use a stone his poorer 
neighbour cannot procure. ‘This seems to have been a mania in 
remote ages as well as recently, and not without a certain value, as 
in many places the old buildings are pointed out as “ not having 
in them a stone to be got in the whole country,” while in modern 
times Rothschild’s French Chateau has brought him historical fame 
on account of the English stone and workmen used in its building. 
Elsewhere on the Continent, in America, besides in the home 
countries, buildings are pointed out, not for any architectural 
beauty, but solely to record that the stones in them were brought 
from a great distance, and at great expense. 

The mania for foreign stones appears to have been very pre- 
valent in Ireland at the beginning of the present century, as in the 
majority of the buildings erected between 1800 and 1840 the stones 
for the dressed work were imported. This is very conspicuous 
in Dublin, as hereafter exemplified in the list of places from 
which the sandstone used in its principal buildings was pro- 
cured. 

As previously pointed out, the early builders, in most cases, 
seem to have selected stones on account of their durability ; but at 
the present time there seems to be, in many cases, a running after 
stones—not on account of their durable qualities, but that they can 
be easily worked, and are therefore cheaper. 


[The Ballycastle stone, Co. Antrim, if it had been well selected, everywhere gave 
good and durable work; yet, at the present time, in the neighbouring towns it is in dis- 
repute, while inferior sandstones are used solely because the first-cost is less. This 
apparently is false economy; for although the first-cost may be less, yet the after 


012 Scientific Proceedings, Royal Dublin Society. 


redressing, or painting, or otherwise doctoring of the stones induce expenses which in a 
short time eat up any little saving there may have been at the first in using inferior 
material. This can also be seen in different places in Dublin, which need not now be 
mentioned, as this subject will be alluded to further on. 


In general, sandstone now in use, except the Caenstone, does 
not appear to be capable of receiving as minute work as limestone. 
However, if we examine the old structures, we find in some of 
them beautiful and elaborate work, but in such cases the stones 
are much harder than those now in request. The exquisite door- 
way of Maghera Church, Co. Derry, cut in the local stone, is so 
durable, that the brushing of the tools can still be seen; but 
this stone would not now be looked at, being considered “too 
hard.” 

According to the records, as left by our ancient buildings, it 
would appear that the soft and more easily worked limestone, 
sandstone, and granite, are best for inside work; but if the work 
is to be exposed to weathering, the durability depended on the 
quartzose nature of the stones, they ranging in the following 
order—quartzose sandstone, quartzose limestone, and quartzose 
granite. The sandstones, apparently, taking in our climate the 
first place. 

There are, indeed, in a few places very quartzose granites and 
limestones of a high order, but they are exceptions to the general 
rule, as the majority of our best preserved old work nearly inva- 
riably is in sandstone. Outside these groups there are, however, 
some stones, but not very commonly met with, that show durable 
work, such as the Camstone, and some of the basalts. 

Quartzose stones, when dry, nearly invariably are difficult to 
work. ‘This is the case with the “ Park stone,’ Wexford, which, 
when worked in its “quarry water,” as exemplified in Roche’s 
Churches, turns out good work. Our ancestors may have under- 
stood this peculiarity in the stones, or it is possible they may have 
overlooked first-costs, and speculated solely on the subsequent 
durability of their work—they working in hard stones that now 
would be condemned. 


[Some sandstones which occur not uncommonly in the Carboniferous formation 
have a latent silicious or carbonaceous cement, and when newly raised, and in their 
quarry water, are soft and easily worked, but subsequently, when dry, they become as 


Kinanan—On Irish Arenaceous Rocks. 513 


hard as a silicious grit. Some stones contract considerably during the drying, and 
stones of this class, before being used, ought to be given time to dry and contract, as 
otherwise they will dry unevenly, and show not only unsightly open joints in the work, 
but are also liable to cause uneven settlements. ] 


The cements of the sandstones are silicious, calcareo-silicious, 
and argillo-silicious. Usually in a contrary order they cut the 
more easily, while their durability is the reverse, except in some 
eases, that is, where they are micaceous, as many such stones, 
otherwise good, are not durable. 

Other examples of well-preserved sandstone carving, besides the 
previously mentioned doorway at Maghera, Co. Derry, are exem- 
plified in the doorway at Killeshin, Co. Carlow, cut in the local 
eoal-measure sandstone; in the massive and beautifully carved 
crosses at Monasterboice, Co. Louth, the stone being a clean- 
grained silicious sandstone. St. John’s Gate, Drogheda, in the 
same county, was built of mixed limestone and sandstone, and it 
exemplified the unequal weathering and durability, the latter 
being perfect, while the others have decayed considerably : it must, 
however, be allowed that the limestone was of a very bad class. 
The dressed work at Mellifont shows the durability of the sand- 
stone. In the latter the bad effects of mica is also exemplified, 
the micaceous sandstones that were used having sadly weathered. 


[The old ruins at Mellifont, during the late repairs under the Board of Works, had 
the rubbish removed, and, as pointed out by Mr. Lynam, County Surveyor, the sand- 
stones thereby re-exposed have rapidly weathered. This I have observed elsewhere, 
not solely in regard to sandstone—as the stones in different ruins, when exposed to the 
drying effect of the atmosphere, have rapidly decayed. This may be seen, as well as 
elsewhere, at Devenish, Lough Erne, where the re-exposed sandstones have suffered, 
and in St. Kevin of Glendalough, Co. Wicklow, where many of the old disentombed 
sculptured schist slabs have, in a few years, been greatly defaced. A cupped stone, 
now in ‘‘ Saint Kevin’s Kitchen,” when first raised, had all the tool markings; but 
these were obliterated by its being allowed to weather for a year. It may appear re- 
markable that stones, when in their natural saturation, that is, having their ‘‘ quarry 
water,’’ harden when exposed, while stones subsequently saturated, when dried, de- 
cay. To explain this, it may be suggested that the first water, that is, the ‘‘ quarry 
water,’’? was in combination with either silica or carbon, the mineral matter consolidat- 
ing as the water evaporated, while in the subsequent saturation, the moisture was 
solely water that had saturated the pores and other vacancies in the stone, thereby ab- 
sorbing the cement, and when this water with the absorbed cement was withdrawn, it 
left the stone more or less a friable mass—at least as far in depth as the absorption had 
effected it.] 


514 Scientific Proceedings, Royal Dublin Society. 


In Boyle Abbey, Co. Roscommon, the stone shows excellent 
work; it is also durable, as in places it still retains the tool 


markings. 


[In America, and also in England, many stones, even when in the quarry, are 
sawn, or otherwise worked and sculptured by machinery ; very little work, however, 
of this kind goes on in Ireland. In some workshops there is sawing and planing ; but 
there does not seem to be a quarry in which the stones are cut in situ: while if a 
building is in progress you generally hear the hammer and chisel, and not the saw or 
plane, at work. However, saws, at least, were known to the early Irish builder as 
in many of the ancient structures the stones, especially sandstones, were sawn, not 
chiselled. The only instance that I can learn of saws being used to cut stone in situ, 
was in the Angliham marble quarry, Co. Galway, where, somewhere about the year 
1860, Mr. Abbott erected a sawing-frame and engine; but when the block was about 
half cut through, the saws broke off, leaving, as Mr. Sibthorpe points out, a puzzleite 
for future geologists to explain how parallel narrow seams of oxide of iron occur in 


the blocks. | 


On reviewing the records of the different Counties, it is con- 
spicuous in how many places the sandstones or conglomerates were 
wrought into millstones. In some places there was a large trade 
not only for home but also for Hnglish uses. This trade, how- 
ever, seems to be altogether a thing of the past, as nowhere, 
as far as we can learn, is it now followed. The manufacture of 
stones for flax-crushing necessarily died out when the new modes 
of crushing, or manipulating, were introduced; but the decline in 
the demand for corn millstones seems to have been solely due to 
the repeal of the Corn Laws, which starved out the industry, and 
caused it to be abandoned. Since then the few stones required are 
imported, principally from France. At the once famous quarries 
of Drumdowney, Co. Kilkenny, there has not been wrought a 
pair of stones since 1875, and then only one pair. 

To some of the good class sandstones not now in request, as those 
near Thurles and Dundrum, Co. Tipperary ; Doon, Co. Limerick ; 
and others mentioned hereafter; public attention may be specially 
directed. 


[When the modern sandstone buildings are tabulated, it at first appears remarkable 
that so many, even in towns at great distances from one another, are all built of stones 
from one quarry. On inquiry, this appears to be due to their having been built by one 
contractor, or under the orders of one architect, the ‘contractor or architect having an 
interest in, or liking for, a certain stone. In Dublin, many of the recent Insurance 
(Offices have in them the same stones, they all having been built by the one contractor. 
But this is more conspicuous in the country towns, especially in the Banks—as the 


Kinanwan—On Irish Arenaceous Rocks. 515 


offices of one company through a large range of country will all be built of one stone, 
while in all those belonging to another company a different stone is used; the stones 
often being brought from a distance, although better stones could be procured in the 
vicinity. | 


GEOLOGICAL EPITOME. 


The Arenaceous rocks range all through the different geo- 
logical groups. It is therefore expedient, before entering into 
detail, to give an epitome of the present state of Irish Geology. 
In this the classification of the groups is that adopted in the 
Taste or Srrata in the first Paper of this series on Irish Economic 
Geology (ante, “ Metal Mining,” p. 204). 


CAMBRIAN AND ARENIG. 
[These groups are so mixed up as to necessitate their being described together. ] 


From the latest fossil evidence brought before the public, which 
is, that supposed Arenig type fossils have been found in the gneiss 
and schist series at Fintown, it would appear that it is now incon- 
testably proved that the oldest rock in Donegal cannot be more 
ancient than Cambrian. Consequently, all the other similar rocks 
in Ireland, which some have called Laurentian, are probably of the 
same age or younger: that is, these metamorphosed rocks must be 
the equivalents of either the Ordovician, Arenig, or Cambrian. 

In 1862 Jukes, and in 1863 Sterry Hunt (after Laurentian 
rocks were proved to exist in Scotland), suggested the possible 
Laurentian age of the Donegal gneiss. In 1865 Murchison an- 
nounced the existence of Laurentian rocks in the Twelve Pins 
(Bennabeola), Connemara, Co. Galway; but immediately after- 
wards he withdrew this statement. In the Geology of Ireland 
(1878), and subsequently in various Papers read before the Royal 
Irish Academy, the Royal Dublin Society, and the Royal Geo- 
logical Society of Ireland, I pointed out that some of the meta- 
morphic rocks of Donegal, Antrim, Tyrone, Leitrim, Sligo, and 
Mayo were probably Cambrians, but possibly Laurentians ; while 
Dr. Hicks immediately afterwards suggested that the rocks called 


SCIEN. PROC. R.D.S.—VOL. V. PT. VI. 2N 


016 Scientific Proceedings, Royal Dublin Society. 


by me Cambrians in the Co. Tyrone were possibly Laurentians; 
and this was followed by Dr. Callaway, who, in 1881, stated that 
patches in my Cambrians, Co. Wexford, were Laurentians. Sub- 
sequently came Dr. Hull, who seems to consider that all the tracts 
of highly metamorphic rocks, except those in Wexford previously 
claimed by Dr. Callaway, are of Archsan age (“ Laurentian 
Rocks in Donegal and Elsewhere in Ireland,” Trans. Roy. Dub. 
Soc., vol. i., ser. ii., p. 245). It seems remarkable that, while the 
rocks of the Mullet, in North-west Mayo, are included in this 
Paper, those of South-east Wexford should be left out, more espe- 
cially as the rocks in both localities are lithologically, microscopi- 
cally, and apparently stratigraphically similar, if not identical. 

The Wexford rocks claimed by Dr. Callaway to be Laurentians 
are, as he has described them, “ a mosaic of irregular fragments” (!) 
protruding into a tract of undoubted Cambrian rocks, as proved 
by their fossils. Nowhere else in the world have the Laurentian 
rocks appeared after this fashion, and I do not believe in their 
existence in the Co. Wexford, as the so-called Laurentians are 
only metamorphic intrudes of Igneous rocks and their associated 
tuffs, similar to the intrudes found elsewhere in every group of 
Trish strata, from the Carboniferous down to the Cambrian. 


[From Dr. Callaway’s Paper, “ Metamorphic and Associated Rocks South of Wex- 
ford’’ (Geol. Mag., Nov., 1881), it is evident that the writer had my memoir, but, at 
the same time, that the maps he was consulting were those published some quarter of 
a century prior to my being in the county or my examination of the rocks. How 
anyone could possibly imagine that my description was that of the obsolete maps is 
hard to conceive; more especially as on these maps are printed the dates of their 
publication and the names of the Surveyors. | 


The Galway metamorphosed rocks that are said to be Lauren- 
tians are undoubtedly the equivalents of the English Ordovicians, 
- as proved by the fossils in the unaltered portions. This will be 
more fully discussed when treating of the rocks of that county, 
while the supposed Laurentian gneiss of the Co. Donegal ought 
now to be disposed of, if the markings exhibited by Dr. Hull at 
the British Association Meeting, 1886 (Birmingham), are Arenig 
types of graptolites, which there now seems to be every reason for 
supposing; for if this be so, it unquestionably proves that the 
gneiss of Donegal, which is part of the same series, cannot possibly 
be more ancient than Cambrian: that is, these rocks must be the 


Kinanan—On Irish Arenaceous Rocks. 517 


equivalents of the rocks of the groups suggested by me in 1878, 
in my Geology of Ireland. 

In the Co. Galway there are no rocks that can possibly be of 
Laurentian age, and the same thing may now be said of the Co. 
Donegal. It is, therefore, only sensational geology to say that in 
the intervening area (Mayo, Sligo, Leitrim, and Tyrone) there are 
Laurentians, more especially as the metamorphic rocks therein 
found are lithologically, and apparently stratigraphically, iden- 
tical with the rocks in Galway and Donegal. In the descriptions 
of those counties in which Laurentians are stated to exist more 
special details will hereafter be given. 


[As it has been assumed in some of the official memoirs that the existence of 
Archean rocks in Ireland has been proved, this subject has to be more promi- 
nently mentioned than would otherwise be necessary. This recent finding of 
Archean has been very sensational from the first. Up to the end of 1880 Professor 
Hull insisted that my classification was probably wrong, as the oldest rocks in 
‘Connaught and Ulster were proved by the work of the Survey to be of Lower 
Silurian (Ordovician) age. But in January, 1881, when Drs. Hicks and Callaway 
suggested that some of my Cambrians were Arehean, quite suddenly Professor Hull 
‘discovered Laurentians in Donegal and elsewhere in Ireland. After seven years of 
steady work in the Counties Galway and Mayo, I classified the older rocks, and 
subsequently traced them from Mayo into Sligo, Leitrim, Donegal, and Tyrone. The 
rocks of the Twelve Pins (Bennabeola), Co. Galway, are lithologically more similar to 
the Huronians of Ontario, Canada, than the rocks in any other place in Ireland. 
These are the rocks which, after Hozoon Canadense had been found in them, Murchison 
atone time suggested might be Laurentians; but the rocks in the same county, said 
by Professor Hull to be of Laurentian age, are evidently the youngest in this part of 
Galway, and in the westward portion of his area, where some of the rocks are very 
little altered, fossils possibly may at some time be found, for as yet they have not been 
properly searched. The rocks of the Slieve Gallion district (Co. Tyrone) and those of 
the Pettigoe district (Counties Fermanagh and Donegal) are partly like those of 
Ontario, but in them are not found the calcareous rocks so well represented in Benna- 
beola, Co. Galway. ‘There are also other rocks in Donegal that are partly like the 
Ontario rocks, such as those in the long tract embracing the Gartan Lakes (Loughs 
Beagh and Akibbon), and extending from them north-easterly by Lough Keel to the 
south end of Mulroy Bay—bits in which area are very similar to Ontario and Assina- 
boia, as seen north of Lake Superior. The rocks of Crann Mountain, Co. Wexford, 
are also somewhat like. As to the gneissose rocks, those of Galway, on the north 
of Galway Bay (which evidently are metamorphosed Ordoyicians), are lithologi- 
cally more like the Laurentians of the Dominion and the States than any other rocks 
in Treland, if we except some small patches of very limited extent in Mayo, and 
perhaps little bits in Sligo and Leitrim; but the gneiss and schist of Donegal lithologi- 
ally are very unlike, while apparently they are identical with the metamorphosed 
Ordovicians of the Schuyllkill River}valley, Pennsylvania (Mount Alban series, Hitch- 
cock, or Hudson series, Dana). In 1884 and 1885 the late Gerrard A. Kinahan, as 
previously mentioned (ate, p. 276), worked out an unconformability in central Donegal 

2N2 


ols Scientific Proceedings, Royal Dublin Society. 


between the later less altered rocks and the rocks of the older series—gneiss with their- 
associated schists (Gartan series). This unconformability in connexion with those 
previously found by Griffith to the north-east, in the Glen valley, and to the south- 
east, between the rocks of the Slieve Gallion district and those to the northward, com- 
bined with M‘Henry’s discovery of ARENIG FossILs in the ‘ Gartan series,’’ ought to- 
make the geology of at least Ulster quite plain ;—the gneiss and associated ‘‘ Gartan 
series” being the equivalents of the Arenig and Cambrian, while the later metamorphic 
rocks represent the upper part of the Ordovician and more or less of the Llandovery (May 
Hill sandstone or Passage beds), the lower portion of the Ordovician (Llandeilo) being 
absent in this province. ] 


The Cambrians or Arenig of Antrim (?), Donegal, Leitrim (?),. 
Sligo (?), Mayo, and Galway are all more or less altered into 
schist, gneiss, or even granite; and in these, at the present time, 
no fossils are recorded, except the recent finds in the rocks of the 
Co. Donegal. In Co. Galway they are found in the Ordovicians, 
but not in the underlying Arenigs or Cambrians (?). In places, 
especially in the Co. Donegal, some of the gneiss and quartzyte are 
very little changed, but in general all the arenaceous rocks are 
more allied to quartzyte or quartz rock (greisen) than to sandstone 
or grits. 

In Dublin, Wicklow, and Wexford, some of the Cambrians are 
metamorphosed, especially in the latter county, where, to the 
south-east, they are changed into gneiss and granite; but in 
places in them are quartzyte and quartz rock (greisen), and in the 
unaltered portion grits and sandstones. 


ORDOVICIAN and LLANDOVERY. 


[In the Table of Geological Strata, ‘‘ Mrrant Minine”’ (ante p. 204), the Passage: 
beds between the Ordovicians and Silurians are called “ May Hill Sandstones,’’ or 
“‘Llandovery.’’ In this Paper the latter name will be used. In Clare, Tipperary,. 
and south-east Galway, the Llandoveries are more nearly allied to the Ordovicians ; 
but in the Dingle promontory, Co. Kerry, they are joined on below the Silurians. | 


Many of these rocks are metamorphosed, as more fully men- 
tioned in the descriptions of the counties. Some of the grits and 
sandstones are capable of dressing well; but only a few of them 
are now in request for cut-work purposes, as the younger and: 
softer stones are preferred. They were, however, used in many 
of the early structures, and proved good and durable stones. They 
were also used in many of the Pre-historic megalithic structures, as 
they were capable of being raised in massive slabs. 


Kinanan—On Irish Arenaceous Rocks. 519 


SILURIAN and DEVONIAN. 


[Except in south-west Ireland (Cork and Kerry), these rocks seem to be rather 
mixed up. The Devonian proper are the equivalents of the ‘‘ Lower Old Red Sand- 
stone,’’ or Passage beds between the Silurian and Carboniferous; but in many places, 
either stratigraphically or lithologically, it is hard to determine whether the rocks 
should be called Devonian or Silurian, as the lower beds of the Silurian (Smerwick beds), 
‘the upper beds of the Silurian (Dingle beds), and the Devonian, are all, lithologically, 
‘more or less identical. Their exact age, therefore, cannot be positively stated, except 
in such places as Cork and Kerry, where good continuous sections across the strata are 
exposed (see Kerry, p. 567). The lower rocks in the Silurian are usually reddish, or 
purplish, and over these are light-coloured fossiliferous rocks (shades of grey, green, 
and blue) ; but still higher up on these, in all the Irish tracts, there are rocks more or 
less similar to those below. Hereafter, in these descriptions, the reddish rocks will be 
called of the ‘‘ Old Red Sandstone type,’’ and the lighter-coloured rocks ‘‘ Typical 
‘Silurians.”’ | 

In some of the new maps there has been a curious dividing up 
of the Silurians: this is especially conspicuous at Lisbellaw, Co 
Fermanagh. This is an interesting locality, as the condition under 
which the “ Lisbellaw Conglomerate”? accumulated, must have 
been very identical with what is now going on at the Chesil Bank. 
In Lyme Bay the “flow-tide” current runs from the westward ; 
and this current, accelerated by the wind-waves, carries the Chesil 
Beach along with it, to be accumulated in the bight behind, or west- 
ward of, Portland Bill, which acts as a groyne. Chesil Bank, or 
beach, becomes coarser and larger as it is followed east, till it forms 
a massive heap of shingle to the west of the Bill; but eastward of 
the Bill, in Weymouth Bay, there are finer accumulations. In 
Silurian times similar forces were at work in the neighbourhood of 
Lisbellaw. Running north-eastward from Lisbellaw was a coast- 
line, while west of the village there was a spit, or “ Bull,” of Or- 
dovician, and west of the latter a bay. Along the north-east and 
south-west shore the “ flow-tide” current ran south-west to Lis- 
bellaw, the shore accumulations increasing in magnitude and 
coarseness from the north-east towards the south-west. Thus we 
find at the north of Lough Eyes their conglomerates lying un- 
conformably on the Ordovician ; to the south-west is the massive 
“ Lisbellaw Conglomerate” accumulated against the Ordovician 
spit, that acted as a groyne; while in the bay, west of the latter, 
sandstones and shales accumulate. ‘Thus, there is a parallel in 
both places, as along the shore-lines the beach gets coarser and 


020 Scientific Proceedings, Royal Dublin Society. 


larger down the current, till it comes to the groyne, when it accu- 
mulates, while westward of the groyne the accumulations are fine 
and small. On the map, for no perceptible reason, the “ Lisbellaw 
Conglomerate ”’ is made to belong to one? geological group, and 
the conglomerates of Lough Hyes to another. (Antea, p. 504.) 

In these groups there are in places sandstone: these, from the 
ancient structures in which they were used, are proved to be du- 
rable, and capable of producing good work; now, however, they 
are not much sought after, except for [local purposes, partly on 
account of their hardness, but more generally on account of lime- 
stone being found in their vicinity—the latter rock, in such lo- 
calities, being now more generally preferredjfor cut-stone purposes. 
Quite recently, however, in a few localities, they seem, in some 
measure, to be rising in public estimation. 


CARBONIFEROUS. 


The Carboniferous sea in the Irish area must have been of 
different depths, besides having in it islands varying greatly in 
dimensions. ‘he rocks deposited in the greater depths seem, for 
the most part, to have been arenaceous and argillaceous (Lower 
Carboniferous Sandstone and Shale, or Yellow Sandstone—Grifiith) ; 
but similar rocks were also afterwards ‘deposited as littoral accu- 
mulations on different geological horizons, even up into the Coal- 
measures ; therefore rocks of this class’are formed not only under 
all the hmestones, but also at different higher levels; they solely 
indicating different localities near ancient land in the Carboni- - 
ferous sea. After atime, in some parts the bottom of this sea 
seems to have grown up, or to have been moved up, causing the 
_ water to become shallow, and the conditions more or less like those 
at the first, so that sandstones and shale (Ca/p), somewhat like 
those at the original bottom (Lower Carboniferous Sandstone), were 
again deposited. : 

In Munster, the adjoining portion of Leinster (ing’s and 
Queen’s Counties), and in north-western Connaught (Mayo), nearly 
everywhere the Lower Carboniferous Sandstone occurs, margining” 
the older rocks, and separating them from the limestone. This, 
however, in general, is not the case in the rest of Ireland. In the 
Co. Wexford, to the north-west of the limestone, are such shore 


KinauHan—On Irish Arenaceous Rocks. 52k 


accumulations, while south-east of the trough there are none, ex- 
cept a few thin subordinate sandstones. West of the Leinster 
range, coming up from the south, these shore-rocks gradually thin 
out, and disappear south of Bagnelstown, not to be met further 
north except in small patches, such as at Newcastle, south-east of 
Celbridge (i/dare), where, we may suppose, there was a cape, 
alongside which a beach accumulated. In connexion with the 
Chair of Kildare, and the other small exposures of Ordovicians, 
that seem to have been islands in the Carboniferous sea, these 
shore-beds only occur at one side of the older rocks. Margining 
the large protrusions of Ordovicians in the central plain of Ire- 
land, the Lower Carbonifereus Sandstones are very continuous, 
while in the west of the Co. Galway, margining the older rocks, 
they are only found at Oughterard and Cong, in places that must 
have been bays. In western Mayo they are very continuous ; 
but in the rest of that county, in Sligo and Roscommon, they, 
in general, only occur to the south or south-east of what was 
the old land: the exceptions being the tracts north-west of the 
western end of the Curlew Mountains (north-east Mayo), and those 
north-west of the Ox Mountains (Co. Sligo). In the large south- 
west and north-east bay, between the Ordovician land, south and 
south-west of Lough Neagh, and the Silurian land, between 
Loughs Neagh and Erne, the Lower Carboniferous Sandstone, ex- 
cept in the north-east portion, was very continuous; but to the 
north of Lough Erne the Carboniferous Limestones, like as at 
Oughterard, were accumulated against an old cliff, sandstones only 
being deposited to the north-east, in the Termon River valley. In 
the tracts of Carboniferous to the northward (Donegal, Londonderry, 
and Tyrone), the shore-beds nearly invariably only occur to the 
north, as in the tracts at Donegal Bay, and westward of Omagh. 
At Feeny, however, westward of Dungiven, there is a small tract 
that seems to have accumulated in a small bight, or bay, where the 
shore-beds were to the southward; while in Fanad, west of Lough 
Swilly, is the small tract to which attention has lately been di- 
rected by Messrs. Hull and Cruise, in which the conglomeritic 
accumulations, as pointed out in a paper by Mr. Mahony, occur 
along the southern shore, and silts occur along the northern. 


[In the Lower Carboniferous Sandstones, and also in the subsequent ‘‘shore accu- 
mulations,’’ there are two distinct types, the lowest beds and those on higher horizons 


O22 Scientific Proceedings, Royal Dublin Society. 


adjoining the shore-line, respectively, being generally of reddish or purplish colours, 
and more or less coarse, often conglomerates. But not always so, as sometimes they 
are fine red shales. Above these, or farther out from the shore, the arenaceous rocks 
become yellow and grey sandstone, with more or less subordinate grey and bluish 
shales. This graduation generally takes place upwards, but not always; as in Galway 
and Mayo, near Oughterard and Castlebar, you can trace, along the strike of the 
bedding, conglomerates graduating into sandstones, and the latter into pebbly lime- 
stones. This also can be seen in various other places, as between Ballyshannon and 
Pettigoe, Counties Donegal and Fermanagh. Griffith was aware that sandstones 
of both these colours and textures were the basal beds, or ‘‘shore beds,’’ of the 
Carboniferous limestone; but, to meet the nomenclature of the day, he called the 
dark-coloured rocks ‘‘ Old Red Sandstone,’’ and for the light-coloured he introduced the 
term ‘‘ Yellow Sandstone.’’ Jukes, however, adopted a different course, as he included 
both together in his Upper Old Red Sandstone. 

Of late years this merely lithological distinction has again, in places, been intro- 
duced and given an unnatural value; so that we find on the new maps little spots 
called ‘ basins of Old Red Sandstone,’”’ solely because the rocks are of dark colour and 
coarser texture, while in other places exactly similar rocks are given their natural _ 
place: that is, they are grouped as the basal or shore beds of the Lower Limestone. 
In Western Mayo the rocks are placed in their true position; but this has not 
been done in Eastern Mayo, although, as pointed out by Symes, the classification 
into two distinct formations is “chiefly lithological’? (Geological Survey Memoirs, 
sheets 41, 58, and 64, page 14, and footnote by Dr. Hull). From the description 
of the rocks of Western Mayo it will be seen that, similarly as Griffith mapped 
them, these ought also to be ‘‘Old Red Sandstone’’ in the eastern area: that is, if 
there is ‘‘ Old Red’’ in the east of the county, it must also occur in the west, if the 
lithological character had been given the same value in both districts (Geol. Mem., sheets 
39, 40, 51, 52, and 62, page 16). Griffith, and subsequently Jukes, were gradually 
bringing Irish geology out from the mists of the past, and it seems regrettable that it 
should now be plunged back again into the dark ages. | 


The fauna of the lower group (Lower Carboniferous Sandstone or 
Yellow Sandstone), although it was unsuited for the clearer and 
deeper waters in which the associated limestones accumulated, did 
not die out, but emigrated to the congenial littoral shallow waters, 
afterwards to again spread out in later times (Calp), when the 
accumulations and conditions were favourable. Thus, we find in 
the Lower Carboniferous} sandstones and shales, in the Littoral 
sandstones and shales, and in the Calp accumulations, that the 
rocks and their fauna are more or less similar. ‘There is, how- 
ever, in places in the Calp, a marked change in the accumulations, 
they being more or less calcareous, and even in places good lime- 
stone. Yet it is remarkable that in them, as in the shaly lime- 
stone of the Rathkeale district, Co. Limerick, the assemblage of the 
fossils is very similar to that of the Lower Carboniferous sandstone, 
in both being found many forms which are not to be met with in 


Kinanan—On Irish Arenaceous Rocks. 523 


the intervening Lower or Fenestella Limestone. It might be said 
that, as the fauna creeps upwards in the littoral beds from the 
Lower Carboniferous Sandstone and Shale to the Calp, it should 
have crept up by similar means from the latter to the Coal-measures. 
This, indeed, may possibly have happened, if John Kelly’s classifi- 
cation of the Slieve Beagh series of rocks (Counties Fermanagh, 
Tyrone, and Monaghan), now favoured by Professor Hull, is correct, 
as these rocks, according to Baily, from paleeontological evidence, 
ought to be classed with the Lower Carboniferous Sandstones and 
Shale. At the same time, however, a very great change seems to 
have taken place when the major portions of the Coal-measures 
were accumulating, as they are not essentially littoral deposits, but 
must, at least in part, represent land and fresh-water accumula- 
tions. Griffith’s term, “ Yellow Sandstone,” seems better, as a 
general one, than “‘ Lower Carboniferous Sandstone,” as it does not 
express on what horizon the rock accumulated, while it suggests 
that the accumulations were marginal between the Carboniferous 
and older rocks; but the latter name seems now to be more gene- 
rally preferred. 

In south-west Munster the Carboniferous rocks are different, 
they being of the “Cork rypE” (Carboniferous Slate and Yellow 
Sandstone). These consist, in a great measure, of slates and 
shales, and they graduate downwards into the Devonian. The 
arenaceous rocks in them are below the Yellow Sandstone, and 
higher up, on different horizons, are the sandstones called by Jukes 
Coomhoola grits. In a few isolated places the Carboniferous slate 
graduates upwards into Ooal-measures ; but in the latter the grits 
and sandstones are of small or no account. Going eastward towards 
Cork Harbour, the Carboniferous Slate becomes split up and inter- 
stratified with limestone ; while further eastward it loses its indi- 
viduality, being replaced by rocks more or less of the “ CenTRAL 
IRELAND TYPES.” 

In the rest of Munster there are below, and also as littoral 
accumulations, the Lower Oarboniferous or Yellow Sandstone (Upper 
or Carboniferous Old Red), and still higher up the grits and 
sandstones of the Coal-measures. The Calp here (more or less 
argillaceous) is a middle division in the limestone, but having 
in places arenaceous calcareous rocks, or, as at Castle Lambert, 
Co. Galway, an impure coal seam. These, however, as sandstones, 


524 Scientific Proceedings, Royal Dublin Society. 


are not of much account, except that in some places they produce 
good flags. Here it may again be mentioned that, in the lime- 
stones of the Calp of the Co. Limerick, there are many Lower 
Carboniferous Sandstone and Shale fossils. 

In Leinster and South Connaught the Carboniferous rocks are 
very similarly cireumstanced to those of North Munster, but in 
North-east Connaught and Ulster there are marked changes. In 
the south portion of Ulster and adjoming part of Connaught 
there comes in as a middle group in the limestone, or as indepen- 
dent groups or beds on different horizons, very pure arenaceous. 
rock; they, the Calp Sandstones, being quite distinct from the 
Yellow Sandstones below and the Coal-measures above. In these 
Calp sandstones, the ‘‘ Fermanagh sandstones,” and the Calp of the 
Ulster type, are procured the stones now of most note in the 
market. Asarule, the sandstones in the Coal-measures are con- 
sidered too hard, although in Leinster some of them are really 
good stones; while the Lower Carboniferous stones are often 
ignored. This, however, may be due to prejudice or some other 
cause, as near Thurles and Dundrum, Co. Tipperary, there are: 
stones said by the builders who have worked both to be better than 
any of the “ Dungannon stones” (Ca/p). 

At the present time the geology of South Tyrone, the asian 
north part of Monaghan, and the adjoining portions of Fer- 
managh seems to be mixed up. In this area, in Slievebeagh, Carn- 
more, and in the country to the eastward, there are sandstones and 
shales that Griffith mapped as Calp, because apparently they were 
identical with the Calp near Dungannon, in Co. Tyrone. John 
Kelly, however, stated that they belonged to the Coal-measures,. 
and called the highest group “ Millstone Grits;” and in the recently 
published maps of the Geological Survey, J oan Kelly’s classifica- 
tion has been followed, and they have been mapped as Lower: 
Coal-measures, the lower portion being called by Phillips’ local 
English name, Yoredale beds ; it being here divided into Yoredale 
sandstone and shales, while the upper sandstones are called Mili- 
stone Grits. 


[It seems very questionable if it is advisable to introduce English local terms into- 
Trish geology, more especially when they are inapplicable. Anyone who has compared. 
the Irish Coal-measures with those of England should be aware that the first ean only 
be compared with the ‘‘ Culm-measures’’ of Devonshire, while there is no similitude- 


Kinanan—On Irish Arenaceous Rocks. 525: 


between them and those of Yorkshire, where Phillips’ name was introduced. What 
English geologist would attempt to divide up the Devonshire ‘‘ Culm-measures”’ into 
Yoredale beds, Millstone Grits, and Coal-measures? The section of the Carboniferous 
rocks in Fermanagh and Monaghan (?) is different to any elsewhere in Ireland. Be- 
ginning below, there is—(1) Lower Carboniferous Sandstone; (2) Shales; (3) Dark- blue,. 
thin-bedded Limestone, with Shale partings ; (4) Amorphous Limestone (Fenestella Lime- 
stone) ; (5) Shales and Limestone ; (6) Sandstone ; (7) Shales ; (8) Amorphous Lime- 
stone under cherty Limestone ; (9) Sandstones ; (10) Shales ; (11) Sandstones, §c. The 
groups 9, 10, and 11 belong to the Lower Coaut-mzEasurzs, and 9 and 10, or Lower 
Coal-measures, may be called the Fermanagh series, after the county in: which they are- 
best developed, and not after ‘“‘ Yoredale,’’? where the rocks are different. Group !1 is- 
a portion of the Middle Coal-measures. Groups 1 to 4 are somewhat like the rocks of 
Munster; but groups 5 to 16 are of different characters and arrangement | 


This tract is interesting. If we begin to the eastward, we 
find sandstones and shales, with small coals, to the north of 
the Tyrone Coat-FieLp (Dungannon), where undoubtedly they 
belong to the middle or Calp division of the Limestone. In them, 
as pointed out by Hardman (G. S. I/.), there are fossils of Coal- 
measure types. South-west and westward of Dungannon are 
small tracts of similar rocks; also farther south-west—unorth-east, 
south-east, and south of Aughnacloy, all of which appear on 
the new maps as Calp sandstone ; but immediately after we cross. 
the Blackwater—that is, leave the Aughnacloy area, and go south- 
west—the apparently similar rocks in the district of Shevebeagh 
are mapped as Yoredale beds and Millstone Grits. Baily contends 
that these rocks ought to be mapped as Lower Carboniferous Sand- 
stones and Shales, as the fossils are of these types; while Kulroe 
states it is difficult to see any difference between the rocks of the 
Slievebeagh district and those of the Calp (G. S. I/.). In these 
rocks of this Fermanagh series (as it will hereafter be called) and in 
the acknowledged Calp the sandstones are very similar, the ‘‘ Dun- 
gannon stone” in the Calp and the “ Lisnaskea stone” in the 
Fermanagh series being of one class and equally in repute. In 
the Calp sandstones north of the Tyrone Coal-field and in the Lis- 
naskea quarries have been found similar large fossil trees, while 
the assemblage of fossils in the Fermanagh series, according to Baily, 
is that of the Lower Limestone Sandstone and the Calp, and. 
is not like that of the Coal-measures. But as the section in 
South-east Fermanagh, between Lisnaskea and Slievebeagh, is 
identical with that of the known Coal-measures in Belmore and 
Cuilcagh (West Fermanagh), it is evident that these rocks of the- 


526 Scientific Proceedings, Royal Dublin Society. 


Shevebeagh district must, at least in part, represent the Lower 
Coal-measures, although they are so different lithologically from 
those of the Tyronr Coat-Friexp to the eastward. 

But it must be remembered, as pointed out in my Geology 
of Ireland (1878), that in the Coal-measures of North Con- 
naught there is a marked change, the lithological characters 
of the Lower Measures being very different to those elsewhere 
in Ireland ;. as below, immediately above the Upper Limestone, 
a more or less thick group of sandstones appear, with subordinate 
argillaceous and calcareous strata; while in the Middle Measures 
there are three coals, one of value. In Tyrone also, but not else- 
where, are found workable coals in the Middle Measures. 

In North Ulster there are other peculiarities, as the rocks 
appear to have accumulated in bays or seas of limited extent ; and 
the different groups of rocks, elsewhere capable of being separated, 
become mixed up; the red and yellow sandstones, the different 
types of limestone, and even shales, identical, except in fossils, 
with those of the Coal-measures, being more or less mixed up. 
‘These rocks, which may be called the Unsrer Catp rypPE, occur 
nearly altogether north of a line drawn from Lower Lough Erne 
along the Silurians of the Fintona district to Lough Neagh, 
excepting the rocks near Cookstown, Co. Tyrone, which are south 
of this line, and have some characteristics allied to those of the 
““ Ulster Calp type.” 

The upper group, or the Coat-mEasurgs, has, as Lower 
Measures in East Ulster, some five hundred to seven hundred 
feet thickness of shale, over which, in the Iiddle Measures, are- 
naceous rocks predominate, while in the Upper Measures there is 
a mixture of arenaceous and argillaceous rocks, with coal. But in 
North Connaught, and the adjoining part of Ulster, there are im- 
mediately above the upper limestone more or less arenaceous strata, 
and above these shales, and these combined represent the Lower 
Measures. Above these are the Middle Measures, which are for the 
most part arenaceous, but having in them workable coals. In 
Eastern Ulster (Tyrone), although the strata of the Coal-measures 
occur in a very similar arrangement to those of Leinster and 
Munster fields; yet in the Middle Measures there are valuabl 
coals. 

At the present time the Coal-measures Sandstone of Ireland, 


Kowanan—On Irish Arenaceous Rocks. K276 


except those of the Fermanagh series, are not in repute, although, 
as displayed by some of the ancient structures, they are capable 
of good and durable work. This will be hereafter mentioned in 
connexion with the respective counties. 

In the West Munster Coal-fields the stones are nearly inva- 
niably hard and chippy, and although they can be dressed on the 
face of the beds, they cannot be worked across, as they chip and 
fly at the edges. In places they produce excellent flags, but to 
give good joints, the edges of them generally require to be sawn, 
as they chip on the face if dressed. These flags, if the edges are 
sawn and the surface planed, make a beautiful even flooring. In 
the Hast Munster (Tipperary) and Leinster Cval-fields there are 
some good stones for dressed work, as hereafter mentioned. In the 
Tyrone or Ulster Coatl-field some quarries have been worked, but 
the stones are not in request, as better can be procured in the ad- 
joining calp; while in Monaghan and Fermanagh are the well- 
known Lisnaskea stones; and in the ConnauGcut CoAL-FIELD 
there are stones said to be good; but as they are very inaccessible, 
and far from any market, very little seems to be known about 
them. Good flags, however, have been sent from this field into 
the market; at one time extensively. 


[The flag trade has peculiar features. About fifty years ago, according to the 
records left by Lewis, the footpaths of very few towns were flagged; but just at that 
time it seemed to have become the fashion, and the different towns were looking out 
for places in which to procure flags. This general demand caused many flag quarries 
to be opened up, and in some places instituted a large industry. But after the towns 
were flagged the demand decreased, some of the quarries having been scarcely 
worked since, while in those places where a trade had been for a time established, 
it has since died out, on account of asphalt being now more generally used than flags. 
However, there seems to be a slight reaction in the favour of flagging, as the asphalt 
in many places seems to be getting into disrepute. In various places in Ireland 
there are large flag quarries, where hundreds of hands were employed, that now 
are quite idle. Belgium sends into the market a large quantity of chimney-pieces, 
made of flag very like that of our Coal-measures; and fifty years ago a large trade 
in somewhat similar work was carried on at Killaloe, Co. Clare, and other places, the 
Killaloe chimney-pieces ‘‘ being in very general request.’’ Now a “‘ Killaloe chimney- 
piece’’ is not heard of, the trade having totally died out; while in the Moneypoint 
flag quarry, on the Lower Shannon, from which the flags came, instead of hundreds of 
workmen, you will rarely find half a dozen. Very superior work of this class used 
also to be turned out from quarries near Mountmellick, Queen’s County, and other 
places hereafter mentioned. The Belgians do their work ‘‘by the piece.’? A man is. 
paid so much for the job ; and he, his wife, and his children, down to a child that can 
scarcely walk, are put todo something, at which they work early and late. In Ireland, 


628 Scientific Proceedings, Royal Dublin Society. 


however, such things are nearly invariably done by days’ work, in limited hours, con- 
sequently in one case the work can be done much cheaper than in the other, and the 
goods sent into the market much cheaper. The Belgian chimney-pieces now in the 
market are enamelled, which was not the case with the Irish chimney-pieces formerly 
in the market. It is for a similar reason—‘‘ cheap labour’’—that the Belgian red 
marbles have cut out, in the English markets, the ‘‘ Irish reds,’’ although the latter 
are superior. | 


PERMIAN. 


In a few places there are conglomerates and sandstones said to 
‘be of this age; but in some places those supposed to be Permian 
are probably Carboniferous, and in others probably Triassic; they 
being the upper beds of the first, and the lowest bed of the other. 


TRIASSIC. 


The sandstones, or Redfree, as they are generally called, are 
free-working stones, and capable of producing fine work. They, 
however, except in a few places, are not durable, also most of them 
are liable to discolour; and although the stones may be selected 
with great care, yet nearly always some will become unsightly, 
spoiling the general effect; still bwldings with dressing and quoins 
-of these sandstones, and walling of limestone, or even basalt, have 
an effective appearance. Exceptions to these general characters 
are the stones of North Down, Scrabo, and Dundonald, as from 
these, especially the latter, stones of good repute are procured. 
The hard texture of these may possibly be due to the associated 
igneous rocks. 


JURASSIC, CRETACEOUS, EOCENE, AND DRIFT. 


In the groups of strata later than the Triassic the few sand- 
stones that occur are of little account for building purposes, they 
nearly invariably being too frail to be thus used. Some of the 
drift sandstones are only in course of formation at the present 
time, sand and gravel being cemented together by water percolating 


through them, charged with carbonaceous, silicious, or ferriferous 
matter. 


Kinauan.—On Irish Arenaceous Rocks. 529 


SAND AND GRAVEL. 


In a few of the older rock groups there are sands that occur 
as rotten or disintegrated portions of beds of sandstones or other 
rocks. These, however, are comparatively rare, as the principal 
places in which the sand and the gravels are found are as portions 
-or beds of the Drift, Alluvium, and Dilucium. Under the latter cir- 
eumstance they often occur in considerable quantities; in some 
places younger drifts being made up nearly altogether of them. 
They have been used in the manufacture of glass, for building 
purposes, for manure, and many of the gravels for road metal. 

The coast sands, that is, those found in the tracts and dunes of 
AMolian sand, which occupy such long and sometimes wide tracts 
in places round the coast-line, seem capable of being made much 
‘more remunerative than they are at present. Jf no other use can 
be found for them they ought to be planted, as has been done in 
‘Gascony, and other places on the wild coast of the Bay of Biscay. 
Their frail nature, and tendency to travel, has given them a bad 
name; but experience in France proves that they will grow fir 
timber profitable for {turpentine and pitch; while after the woods 
are established, the shedding of the leaves and the roots of the 
trees fix the sand so, that portions, if judiciously cleared, can be 
converted into excellent and remunerative tillage-land. It should, 
however, be mentioned, that in Ireland, in a few places, by judicious 
management, they have been made more or less remunerative. 

Many of these Atolian sands, especially when Calcareous, ought 
to be extensively used as manure. Some of them were utilized for 
this purpose formerly ; but of late years nearly all are ignored, as 
the artificial manures can be more easily procured, although even- 
tually at a much greater cost. 

There are other sands, also gravels, valuable as manure ; these 
will be mentioned in their respective counties. 

For the ancient bronze castings the mould in general seems 
to have been cut in sandstone, as many such moulds are found in 
the old settlements. In modern times they are generally made of 
sand. As to where the sand used for these moulds in the different 
foundries was procured we can give very little information. 

Adjoining the Arklow Chemical Works a barricade of upright 
timbers was erected to prevent the mass of At¥olian sand, during 


530 Scientific Proceedings, Royal Dublin Society. 


east and north-east gales, from drifting and blocking up the quay 
and entrance to the works. ‘Through the fine joints of the 
timbers in this barricade a minute silicious sand drifted, and this 
has been found to be highly valuable for use with the saws of the: 
marble and other stone-cutters, it being sent to Dublin for these: 
purposes. Ireland seems to be remarkably deficient in “sharp- 
sand ’’ suitable for stone-cutting, most of it being imported. Here, 
therefore, there appears to be a suggestion as to the introduction 
of a new industry; for in different places along these Arklow 
ffiolian sands, or on the other accumulations of silicious sand along 
the south-east coast, similar barricades to that at Arklow might be: 
erected, and the fine sand drifted through them sent into the 
market to meet the present deficiency. 

Guass.—As to the former Glass trade, we have the records of when 
it was established ; but in most cases it is impossible now to find 
out where the sand came from. In some cases, however, we know 
that Irish sands were used. As glass beads are common as Irish 
antiquities, they seem to suggest that in old times our sands, in 
different places, were used in the manufacture of glass. 

In different cases, as will be hereafter seen, the qualifications. 
of a stone is a vexed question; as what one authority approves, 
another disapproves. Where the opinions are conflicting, the 
names of the authorities are given. In many cases this disagree- 
ment may be more apparent than real, as in most quarries there 
are different classes of stone—one sent to one market, another to 
another—so that the opinions expressed, although apparently in 
reference to one and the same stone, may not be so. Also, in 
some of the quarries all the good stone, once in good repute, may 
be now exhausted. Fifty years ago all the builders knew the 
‘Slush stone,” Co. Fermanagh; while if you ask the men of the 

“present day their opinion of it, probably they never heard of it, 

its day having long since passed away, as the good stone in it 
has now become too expensive to work on account of the “off 
baring.” 

Necessarily, in a Paper of this kind, some of the statements 
may require modification, or other correction; while there may be 
quarries left out of the lists that ought to have been mentioned. 
Such omission, however, will, as far as possible, be corrected 
hereafter in an Appendix. 


Kananwan—On Lrish Arenaceous Rocks. 53l 


The descriptions are given in the counties, arranged in alpha- 
betical order, under the different Geological groups, as adopted in 
the Table of Strata in the Introduction to the Paper on Merar 
Minine (ante, p. 204). The records of the Sands and Gravels are 
not as full as they ought to be; but on these subjects it is hard to 
get satisfactory information, as most previous writers have, in a 
great measure, ignored them, except in general description, from 
which very few details can be learned. 

In the compiling of this Paper, as in the previous one on 
“‘Marbles and Limestones,’ I have necessarily been greatly in- 
debted to Wilkinson’s standard work; and of all stones mentioned 
by him his descriptions are given, except that his arrangement is 
modified to suit mine. I have also consulted Lewis, and the 
Memoirs of the Geological Survey, the quotations from the latter 
being initialed G. S. 17. But the information from Lewis cannot 
be specially acknowledged, it being too general, and having after- 
wards to be verified. I have also received valuable information 
from the Officers of the Board of Works, through Mr. Commis- 
sioner 8. U. Roberts; some of the County Surveyors, and various 
private individuals; whose aid, when possible, has been acknow- 
ledged ; but in many cases this was impossible, as the same in- 
formation was received from different sources, or the different 
information about one place had to be incorporated. 


COUNTY HISTORIES. 


ANTRIM. 


AReENIG (?) or Orpovictan (?).—'To the north-east of the 
county, principally in the barony of Cary, now better known as 
the Ballycastle district, is a considerable tract of metamorphic 
rocks, probably the equivalents of either the Ordovician or Arenig. 
Among these are some rocks that still in part partake of the nature 
of grits or quartzyte, but none of them are eminently suitable for 
cut-stone purposes. 


SCIEN. PROC. R.D.S.—VOL. V., PT. VII. 20 


O32 Scientific Proceedings, Royal Dublin Society. 


Srrur1aAn.—On the east coast, in the neighbourhood of Cushen- 
dun, there are massive conglomerates associated in places with 
sandstones. ‘These rocks seem evidently to be a portion of the 
littoral or shore beds of the Ulster and Connaught Silurian Basin, 
heaved northward by the faults of the Lough Neagh valley. 

In places some of the conglomerates can be raised in blocks 
very suitable for piers and other rough work, while some of the 
finer beds can be used for cut-stone purposes. “‘ The fine beds at 
Cave House were at one time largely quarried, and shipped to 
Belfast for building purposes” (G. S. JL). 

CarsonireRous.—Near Benmore, or Fairhead, is a small tract 
of Ulster-type Calp, where there were some workable beds of coals, 
for which reason it is commonly known as the BaLiycAstLE CoaL- 
FIELD (see Antrim, “ Metal Mining,” ante, page 264). Here are 
some stones of great durability ; but as some beds are better than 
others, they should be selected with care and judgment. The best 
stones are whitish or creamy, finely granular, nearly entirely sili- 
cious, but slightly micaceous, and having a few iron spots. Some 
beds, although otherwise good, are liable to discolour. 

Ballyory Quarry.—Three miles from Ballycastle, where there is 
a railway station. Wilkinson thus describes the stones: “ Best 
stone very fine-grained and friable, almost entirely silicious- 
grained, slightly micaceous, and with a few iron spots; works 
easily and well. In selecting the stone, blocks showing iron spots 
should be rejected.”’ But Mr. Gray says: “ Irregular in texture, 
gritty, and in many beds soft. Carefully-selected stones stand 
exposure ; but as a rule it is not a good stone.” 

In colour it is pink-white or creamy. Of the latter there 
are two kinds, one coarse-grained and very strong, admirably 
- suited for bridges, piers, and other strong work. It has been used 
for many of the bridges in the Co. Antrim, including the via- 
duct, in places 90 or 100 feet high, over Glendun, in the latter 
having been used in all the most particular and trying parts. 
This viaduct has now been a great many years built, and there are 
not the slightest symptoms of decay in any of the Ballycastle 
stones used therein. The Ballycastle bridge, after it was carried 
away, was rebuilt in 1852 with this stone, and the chisel brushings 
are now nearly quite fresh. Here the durability of the stone has 
been considerably tested, as during spring-tides they are wet, and 


KinaHaAn—On Irish Arenaceous Rocks. 533 


at other times, especially during the heat of summer or in frost, 
quite dry. ‘These tests the stone has stood well. 

The second is a fine stone, taking a beautiful edge, and suitable 
for the finest work. It can be worked on any surface, where it is 
equally durable, as it does not require to be laid on its own bed. 
The spire of Ballycastle Church, built in 1756, is of this stone, 
and has remained perfect ever since. It was also used for dressing, 
facing, and other purposes at Doon Hill, Co. Londonderry, built 
by Lord Bristol, then bishop, in 1783 to 1785, and the cornices 
and fine work are still quite fresh. In Belfast it contrasts favour- 
ably with other sandstones. The spire of the Charitable Institute, 
built 1774, is of this stone, and also the portico of St. George’s 
Church. The latter was originally in Lord Bristol’s palace of 
Ballyscullion, and was removed to Belfast after the palace was 
burnt down. These have shown no signs of decay, while English, 
Scotch, and other stones in the Belfast structures have had to be 
painted or re-dressed. This stone was also used for the dressings 
in the Grain Market; and in Coleraine for the inside dressings 
ain the church. It was formerly used largely for Tombstones, 
but at present only a little. 

In Ballymena, the nearest large town, it is not now used, as 
the Scotch stones are cheaper. The Dungannon stones, Co. Tyrone, 
are, however, still cheaper, costing 4s. a ton, while the Scotch is 
10s. ‘The spire and dressings of the west church are of the Dun- 
gannon stone, while it is also generally used for window-sills and 
such like. The quarries about Dungannon yield different stones. 
From Bloomhill come the stones most used and preferred in Bally- 
mena; but in Belfast they prefer the Ranfurly and Carlan stones. 

Fair Head.—Red. Works freely ; durable; used throughout 
in the Ballycastle Coastguard Station. (J. Cockburn.) 

Triassic.—This occurs more or less as a fringe, margining 
the later rocks to the eastward. It is commonly known as “ Red 
Free.”’? This sandstone works easily and finely, but almost inva- 
riably it is very friable and weathers quickly. Some of the hardest, 
stones are quarried in the vicinity of Red Bay and at Bank Head, 
near Larne. There are also various quarries in the valley of the 
Lagan. 

For Belfast the ‘‘ Red Free” is usually brought from Scrabo 
and Dundonald, Co. Down, where the stone is much harder and 

202 


oo4 Seientifie Proceedings, Royal Dublin Society. 


better than in the Co. Antrim. The principal sandstones used in 
Belfast are given under Co. Down. 

Creraczous.—In places, under the White Limestone (Indurated 
Chalk), are sandstones, supposed to represent the Hnglish Green- 
sand. These are locally known as mulatto stones. They oc- 
casionally are firm enough to be used as building stones; but 
in general, as pointed out by Wilkinson, they are “too friable 
and loose-grained to be suitable for good work.’’ Du Noyer has 
stated that, in the Cretaceous rocks of Colin Glen, there are some 
fine-grained, thin-bedded sandstones, which were used for litho- 
graphic purposes. 

Fruints.—The flints in the White Limestone, as mentioned in 
the Paper on “ MarsiEs anp Limestonss” (ante, page 413), were, 
in prehistoric times, largely used for the manufacture of arrow- 
heads and other implements, being exported into the neighbouring 
counties. In later times they were wrought into gun flints. So. 
late as 1840 there was a large export of flints from the Whiterock 
quarries, near Dunluce, to supply this trade and the Staffordshire 
potteries. Since then flints have been exported from Glenarm 
and other places for the English potteries and that at Belleek, Co. 
Fermanagh ; while the Eglinton Chemical Co. grind up the flints, 
and from the powder manufacture silicious bricks, that can stand 
any heat, and are in great request for the lining of steel furnaces. 

AGatEes.—Some of the flints on Rathlin Island are ribanded, and 
appear capable of producing beautiful “ onyx” and “ sardonyx,” if 
we may judge from the specimens in the Science and Art Museum, 
Leinster House, Dublin. As is well known, the old Greeks and 
Romans, who ranked agates high among their precious stones, in- 
vented a method of staining them. This for years remained a 
secret with the Italians, till an Italian and German, at one and the 
same time, both agate cutters, got into trouble in Paris, and while 
in prison together the Italian cummunicated the secret to the 
German. Since then the great trades in agates at Oberstein in 
Germany has sprung up, the major portion, if not all, the rough 
agates being imported from the La Plata River, America, the 
German quarries falling into disuse after the American cheaper 
supply came into the market. 

As far as we can learn, there seem to be no records of these 
Rathlin agates im Leinster House as to whether they are the 


KinaHan—On Irish Arenaceous Rocks. » O39 
stones as found iz situ in the island, or if rough agates that 
afterwards were stained. In the Ballinascreen Hills, northward 
of Draperstown, Co. Londonderry, the “chalk conglomerate,” 
the basal bed of the Hocene, is in a great measure made up 
of broken flints, that were baked by the subsequent over- 
flow of basalt. In all the naturally stained agates I have 
seen the colours developed are shades of red, they being of the 
“carnelian” type, as may be seen in the flint fragments i s¢éw, 
and in the flint implements found in the valley of the Lower 
Bann, Co. Londonderry. Symes states that the agates of this class 
are common everywhere in the North of Ireland, where the basalt 
lies direct on the Hocene basal conglomerate, that is the rock due 
to the breaking up and re-arrangement of the surface of the lime- 
stone. He suggests that the staining is due to an iron solution, 
combined with the baking due to the overflow of hot basalt. ‘The 
process must be more or less allied to the artificial production of 
“‘carnelians;”’ but as the natural ones are more opaque than the 
artificial, an iron solution, as suggested by Symes, may be present. 
At present we are unable to say if the Rathlin “ onyx ”’ and “ sar- 
donyx,” as seen in the Science and Art Museum, Leinster House, 
Dublin, have been procured in situ, or if they were afterwards 
artifically stained. The stones, however, whether naturally or arti- 
ficially stained, give such good results, that they ought to be 
worth looking after; not, however, for a trade in the island in 
cutting and polishing, for labour is so cheap in Germany that it 
would be impossible to compete therewith ; but the raw material 
might be exported to Germany, as it is at the present time 
from the River La Plata. 


[In the ‘‘Gronoey or Inp1a,”’ Pt. iii., pp. 506, &c., Ball gives an interesting 
and exhaustive account of agates, and how the colours are produced. Many of the 
raw Indian agates are identical with those from Antrim, while their origins seem to be 
very similar, both being baked by overflow of basalt. Besides being used for orna- 
mental purposes, they are largely manufactured into burnishers. | 


Sanp anp Graver.—As a subordinate adjunct of the flows 
of Eocene basalt, Lewis records a rough tripoli found at Agnew 
Hill. 

In various places in connexion with the Drift, the alluvium and 
the diluvium, are sands and gravel. In the drift near Ballycastle 


O36 Scientific Proceedings, Royal Dublin Society. 

there are valuable sands, due to the weathering of the sandstones of 
the “ Ballycastle Coal-field ”’ (Ca/p), mentioned under Glass here- 
after. Red sand suitable for foundry purposes is procured in the 
valley of the Lagan, and exported from Belfast. 

In the valley of the Bann is a deposit of Diatomyte, or 
“Diatomaceous clay.” This, although properly a sand, is so fine 
that it has come to be regarded as a “clay,” and the notice of it 
in this and other counties will hereafter be given in a subsequent 
paper on “Slates and Clays.” 

For mortar, excellent »iver-sand is procured from Lough Neagh,, 
near Antrim. Near Lisburn and Ballymoney there is pit-sand ; 
but as the latter is mixed with clay bands, it has to be carefully 
raised. At Hollywood there is good sand; at Ballycastle, as 
already mentioned, there is also good sand; and at Larne there is 
sea-sand on the beach. 

In some places on the coast-line there are Molian sands, that are 
carted inland, to be used as manure, especially on peaty soil. At 
Red Bay the Atolian sands bring large rents, they being rented 
and cultivated by the inland farmers for potatoes, to change the 
character of the seed, a worn-out stock being renovated after it has 
been grown in these sands. 

Guass.—In the neighbourhood of Ballycastle there is an excel- 
lent sand, due to the weathering and washing of the Carboniferous. 
sandstone. ‘This seems to have induced the manufacture of glass. 
at a very early period, possibly in prehistoric times (see ante, 
page 265). Of late the glass trade was for the most part an export 
of bottles to Scotland. It declined as the native coal increased in 
price, and finally died out when the glass-house was destroyed by 
lightning in 1850, or thereabouts. 


ARMAGH. 


A considerable portion of the county is occupied by Orpovi- 
ctANs ; but none of these sandstones, or grits, seem to be favourably 
received as a building stone. 

To the north of the county, in the Blackwater Valley, are 
CARBONIFEROUS sandstones. Some of these, of reddish colours, 
were said to be of Permtan age; but the fossils in them suggest 


Kinanan.—On Irish Arenaceous Rocks. B/ 


that this cannot be correct. Some of these sandstones will dress 
fairly well, but they are not in general request. 

Grange. North-north-east of Armagh.—A_ free-working, fine 
sandstone, considered to be inferior to the ‘“ Dungannon stones,” 
Co. Tyrone, and those of Lisnaskea, Co. Fermanagh. It was used 
during the restoration of the Armagh Cathedral in 1835; but for 
the dressed work foreign stones were used, as presently mentioned. 

At Armagh there are conglomerates that are said to be Per- 
mians. Possibly they may be of that age, that is, the ‘‘ Passage 
rocks,” from the Carboniferous to the Trias; but it seems more 
probable that they are the basal beds of the latter. They lie 
nearly horizontal, as do also the Carboniferous rocks below, and 
the Trias rocks above, so that their exact age is hard to determine. 
These formerly were rather extensively used for ordinary building 
purposes, and some beds for flagging in Armagh. 

Trrassic.—Sandstones, or “ Red Free,” occurs to the North of 
the county, in the valley of the Blackwater, and at Armagh, and 
seem formerly to have been utilised; but of late they are not of 
repute. Between 1840 and 1846, when repairing the Cathedral at 
Armagh, “ English reds” were used for the carved head, while 
about the same time Scotch stones were imported for Lord Lurgan’s — 
new house. 

In the vicinity of Armagh, near Redbarn, at the bottom of the 
red beds, either in the Trias or the so-called Permian, is a Calcare- 
ous, hard, red breccia that has been used for flagging in Armagh. 

Sanp AND Gravet occur in the drift alluvium and diluvium. 
Good sharp sands for building purposes are found on the shores of 
Lough Neagh, near Lurgan, while good river-sand occurs about 
two miles from Armagh. 


CARLOW. 


The only sandstones and grits belong to the CaRBoNIFEROUS. 
They occur in the Lower Coal-measures that extend from Kail- 
kenny and Queen’s County into the western portion of the county. 
Although not now in request, being only used for local building 
purposes, they are capable of fine and durable work, as may be 
seen in the exquisitely carved and beautiful doorway of the an- 
cient church in Killeshin Glen. The principal quarry in them is 


538 Scientific Proceedings, Royal Dublin Society. 


at Killeshin, about two and a-half miles from Carlow, on the road 
to Castlecomer. The stone occurs in nearly horizontal beds, from 
10 to 24 inches in thickness, of a brownish-grey colour, silicious, 
naturally jointed, and easily raised. From the same strata are 
procured the so-called ‘‘ Carlow flags.” The principal quarries 
for these flags are, however, in the Co. Kilkenny, as is afterwards 
mentioned. 


SanD AND GraveL.—Sand is found in the alluvium and dilu- 
vium, while the upper drift (Esker drift) above the boulder clay or 
glacial drift is nearly altogether gravels and sands. ‘These, in 
places, are cemented into a conglomerate bed, having associated 
with them beds of brick clay, to be subsequently mentioned in a 
Paper on Slates and Clays. Good pit-sand can be procured in all the 
pits, which are numerous in the valley of the Barrow, but perhaps 
more in the Queen’s County (west of the river) than in Carlow. 

There is a large extent of good pit-sand and gravel at Carlow 
town, about the railway station, and along the roads running out 
at that side, where they form the lower stratum of the alluvial 
soil for a considerable distance. 


CAVAN. 


The sandstones belong to the Ordovician and the Carboni- 
ferous. 

Orpovictan.—These rocks, although of considerable extent, 
contain few rocks eminently suitable for cut-stone purposes. Some, 
indeed, work fairly well; but as good limestone or sandstone of a 
later age are conveniently situated, they are not looked after. 

Scrably. North of Lough Gowna; eight miles from Granard.— 
Brownish, ferriferous, slightly calcareous; works fairly, but is 
hable to lose its colour. 

Carponirerous (Lower Carboniferous, or Yellow Sandstone).— 
In this group, in the neighbourhood of Cavan, there are some 
easily-worked stones of a yellowish-grey colour, that have been 
extensively used in the town. 

Latt and Ballyconnell (Cavan).—Yellowish-grey, silicious, dur- 
able ; works freely. Used in the Cullen College, built 1871. 


Kinauan—On Irish Arenaceous Rocks. 539 


To the north-west of the county, in the Coal-measure of the 
Cuilcagh and Benbrack Hills, there are said to be some beds of 
good stones. These, however, have been rarely worked, and, for 
the most part, are unknown on account of their backward situa- 
tion, and the difficulty and expense of bringing them into the 
market, railway charges being so high. They were, however, once 
largely wrought into millstones, and next to those from Drum- 
downey, in Kilkenny, were highly esteemed. 

Sanp and Graver.—Usually these are scarce in the county, 
especially near the capital town, as for building purposes sand has 
to be procured from a considerable distance. At Bailieborough 
there is a red pit-sand, but not very good. 


CLARE. 


OrpDovVICIANS occur in the mountain groups of Slieve Aughta 
and Slieve Bernagh. In these are grits and sandstones, but not of 
much account, except for rough work. There is also a green rock, 
full of little round bits of quartz, from the size of shot to that of 
peas, locally called “ Porphyry.” It isa hard massive stone, good 
for heavy work, but rises in unsightly blocks. 

CarBoniFERoUs.—Margining the Ordovicians, and in a small 
outlying exposure between Newmarket and Bunratty, are Lower 
Carboniferous Sandstones (Upper Old Red). The stones vary much 
in colour, from nearly white to yellow, reddish-yellow, and red or 
purplish. Good stone can be got in many places; but there are 
so many good and large surface-blocks, that only a few quarries 
have been opened. The stones in the hills, about ten miles from 
Scariff, have very silicious grains in a felspathic cement ; they 
work rather easily, but wear the tools rapidly. 

Ballyheique. Near Scariff.— Yellowish, gritty, with little 
cement; ferruginous spots; not difficult to work. In 1842, and 
following years, this stone was extensively used in the works for 
the improvement of the Shannon at Killaloe, and subsequently 
was used for the Workhouse, Scariff; but in Scariff it is not 
much used, as they prefer the stones procured in the hills, about 
ten or twelve miles distance. 

A vein of excellent stone, equal to the Tyrone stone, is said to 


540 Scientific Proceedings, Royal Dublin Society. 


exist near Mount Shannon, at the bounds of the Co. Galway and 
this county. 

As pointed out by Wilkinson, the stonework of the ancient 
Crypt and Cathedral at Killaloe attest the durability and quality 
of the sandstones of that neighbourhood. 

To the west of the county, in the Coal-measur es, the sandstones 
and grits are usually thin-bedded, brownish, and bluish-greys, 
close-grained, and compact. They are very good for general 
building purposes, being very durable, and having flat beds, make 
very strong, good work; otherwise, they are not much used, 
being expensive to quarry, on account of the great head (over- | 
baring) of drift. They are also difficult to dress, and for cut- 
stone purposes limestone is generally used in the district. 

Ennistimon.—In beds or layers, from 2 to 8, or 10 inches thick. 
Dark-grey ; close and compact; very silicious. Makes good wall- 
ing. Very difficult to work. 

Crag. One mile from Kilrush.—Flags like those at Money 
Point. 

Money Point (on the Shannon).—Flags somewhat like the Car- 
low flags, but much darker; rough on the surface from tracks of 
marine worms and other animals. They have been extensively 
quarried, and exported to different places along the coast of the 
south-west counties. Formerly they were extensively manufac- 
tured into chimney-pieces, at the Marble Works, Killaloe, where 
there was machinery for cutting them and planing their surfaces. 
At one time the Killaloe chimney-pieces were well known in the 
market, and the Works employed a large staff of men, women, 
and children. Some thirty years ago, however, this trade seems 
to have died out, and now the “ Killaloe Marble Works” exist 
only in name. 


[The history of the Killaloe Marble Works I have not been able to unravel. Kil- 
laloe is most favourably situated, having the command of the greatest water-power in 
Treland, and ought to be one of the great centres of industry; but for some reasons all 
this great water-power is allowed to remain idle. Prior to 1850, the Killaloe Works 
were a great source of employment, not only in the town, but in the flag quarries on 
the Lower Shannon, and in various marble quarries, principally in Counties Tipperary 
and Limerick. All of these quarries seem to have failed when the Killaloe Works 
ceased. | 


Sanp anp GraveLt.—Very superior crystalline sand is found on 


Kcinanan—On Irish Arenaceous Rocks. 541i 


the shores of Loughs Graney and Coutra. The former were exten- 
sively used for the manufacture of scythe boards, the sands being 
carried for that purpose into the neighbouring counties, as boards 
made from them were considered far superior to those made from 
English sands. This sand is the detritus from the Lower Carboni- 
ferous sandstone, in which there are beds that were formerly wrought 
by hand into scythe stones. These were carried by hawkers, and sold 
to the traders in Ennis, Limerick, Nenagh, &c., or at the different 
markets and fairs in the neighbouring portions of Connaught, 
Munster, and Leinster. Before the ‘“‘bad times” in 1848 and 
subsequent years, very few mowers along the Shannon and its 
tributaries used any but “Clare stones” and “Clare boards;” but 
during that time the making of them ceased, and Hnglish and 
Scotch stones had to be used. A few of the makers who survived 
the famine attempted to revive the trade, and in 1860 there were 
a few families in Glenomera and Glendree, near Feakle, working 
at them. The foreign stones, however, held their own, as they 
could be sold much cheaper ; also they suited the scythes then in 
the market, as those imported are much softer than those previously 
made in the country, the former wearing out much quicker than 
the latter. Fifty years ago a mower on the Callow, along the 
Shannon, would have a scythe to last him two or three seasons ; 
now the imported scythes never last more than one. ‘The cheap 
seythes retard the work considerably, as the mowers have to stop 
so often to whet their seythes. 


[As pointed out in the Paper on ‘‘ Metal Mining ’”’ (ante, page 306), the Irish iron 
was much superior to that now in use. There are not now, as far as I can learn, any 
authentic records as to the quality of the steel, except the traditions of certain smiths 
who could make a scythe that would ‘‘cut wool floating on water,” or a scythe that 
had not to be whetted for an entire day. Such legends are still to be heard in the 
neighbourhood of the Shannon and elsewhere. ] 


In the barony of Burren sand and gravel are scarce, being 
nowhere in abundance. In the neighbourhood of Ennis there is 
good pit-sand; three miles from Scariff there is good river-sand ; 
while at Lahinch and Kilrush there is good sea-sand. 

In places along the coast-line there are duns or accumulations 
of Molian sand, and in the estuary of the Shannon manure or shell 
sand, formerly extensively utilized. 


542 Scientific Proceedings, Royal Dublin Society. 


CORK. 


In this county sandstones and grits are the principal rocks, 
they being of Silurian, Devonian, and Carboniferous ages. (See note 
on Old Red Sandstone, under Kerry, page 568.) 

SmturR1AN AND Devontan.—The rocks of the hill country to the 
north and west of the area nearly all belong to one of these divi- 
sions, Carboniferous rocks only being found in portions of the valley. 
The Silurians (Glengariff grits) and Devonians (Lower Old Red 
Sandstones) are locally cailed “brown stone” and ‘red stone,” 
while the Carboniferous sandstones (Vedlovw sandstones and. Coomhoola 
grits) are known as “ grey stone.” 

In numerous places in the Silurian and Devonian excellent 
and durable stones for tool-work could be procured, as is exhibited 
in the various ancient buildings, Limestone, however, is now 
generally used for dressings and other cut-stone purposes. This, 
in a great measure, seems to be due to the architects and workmen, 
who have learned and live in the cities where limestone is used, 
objecting now to use the sandstone; the workmen especially, as 
sandstones are much harder on their tools than limestones. Lime- 
stone, however, in early times, in places superseded the sandstone, 
as at Cloyne, where the sandstone in the Round Tower was pro- 
cured between its site and the shore; while the other ancient 
structures, but more recently built, are of limestone brought from 
a distance. 

The Round Tower of Cloyne, just mentioned, displays the 
excellent qualities and durability of the stone of the neighbour- 
hood. It is of a light, brownish-coloured sandstone, the work 
being good, especially round the doorway. Of the work Wilkinson 
‘states that the stones are notched one into the other in a peculiar 
manner ; also that their state of preservation shows the durability 
and sound quality of the material. 

From the list given (page 545) and descriptions, for which I 
am indebted to Mr. Williams of the Board of Works, it would 
appear that some of the South-west Cork sandstones are well 
worthy of more attention than they now receive. 

Sherkin Island, off Baltimore Harbour.—The stone, when first 
raised, 1s greyish; then it becomes tinged with green, probably 


Kanauan—On Trish Avrenaceous Rocks. O4e: 


due to minute particles of grey copper. It afterwards loses the 
greenish tinge, but never returns to its primitive colour. It has 
been extensively used in Skibbereen, where it displays good work, 
especially in the Roman Catholic church; while its durability is 
tested in the older buildings. This vein of stone is of considerable. 
extent, being found to the westward in Clear Island, and eastward 
on the main to the south and south-east of Baltimore Harbour. 

Horse Island.—A. loose, friable, brown freestone, which has 
been extensively quarried. 

Drumcona, six miles from Skibbereen.—Greenish ; hard; semi- 
vitreous, with calcareous patches; cuts and dresses well. This is a 
superior stone to those on Sherkin; but the quarry is very inacces- 
sible. 

Glandore.—A. good greenish grit, formerly much used. In the 
ruins of Ballymoney Castle its durability is tested. It was also. 
used in Kilcoleman House, four miles from Bandon. 

The quoins and chimney shafts at Aughadown House, in the 
east division of the barony of West Carbery, are good examples 
of the stones of the neighbourhood. 

Knockarowra and Cloghlucas, near Mallow.—Brownish-grey ; 
slightly argillaceous; suitable for plain work. 

Rahan Mountain, four miles from Mallow.—Reddish; ferru- 
ginous ; fine-grained. A superior stone to those nearer Mallow. 

Quarry Mountain, near Mallow.— Reddish; silicious, but 
slightly calcareous; semi-crystalline. 

Mountain between Mallow and Kanturk. — Dark-brown ; 
quartzose ; semi-vitreous; hard. 

Knightfield, three miles south-east of Banteer Railway Station 
(commonly known as the “ Kanturk Quarry’’).—Used for the 
quoins and sills of the Lismore school, six miles from Kanturk. 


[The following two localities in the Knockmealdown range may be in the “ Yellow 
Sandstone.” | 


Killemera, near Glanworth.—A nice sandstone for walling 
purposes. 

Araglin, north-east of Fermoy.—Grit stone ; gives well-shaped, 
superior paving setts. 

Two miles south of Fermoy is a very good variegated stone, 
that cuts and dresses well. It was much used formerly, but after- 


544 Scientific Proceedings, Royal Dublin Society. 


wards was in a great measure superseded by limestone. Bishop’s 
Wood, near Fermoy, supplies flags. 

Glanmire Road, Cork.—A. deep-red, fine-grained stone. 

Templegall, or Whitechurch, seven miles north-west of Cork.— 
Good building stones and flags. 

YVoughal.—A red stone, lighter in colour than the Cork stone. 

In places there is a conglomerate (trappean), which can he 
worked into good square blocks, best suited for heavy work, such as 
bridges, foundation walls, and the like. 

CarBoNnIFEROUS.—In this formation there are sandstones and 
grits at the base (Yellow Sandstone); and higher up in the Carbonije- 
vous Slate, at different horizons, are the Coomhoola grits. In places 
many good stones could be procured, but they are not much sought 
after, being hard and silicious, and quickly wearing the workman’s 
tools. 

A good freestone has been worked on Horse Island ; also near 
‘Castletownsend; while, in the Devonshire property, near Bandon, 
and in the Herrick estate, Innishannon, there are extensive 
quarries. 

Tn the parish of Brinny, north-east of Bandon, are flags of ex- 
cellent quality, and in Kilbrogan there is freestone that has been 
extensively used in Bandon. 

A little north of Cork, on the north of the River Lee, the stones 
in the quarries vary. They are thus described by Wilkinson :-— 
Yellowish-white, close, compact quartzy grains, with felspathic 
cement, and semi-vitreous; also, green, silicious, close, dense, very 
compact, but with numerous fissures and bedded portions, the 
latter causing the stone to fail. 

Belleview Quarry. Near Cork.—A good and free-working 
stone; but the workmen prefer the limestone, to which they are 
accustomed. | 

Coolconing. Two and a-half miles north of Kinsale. — Yellowish, 
brown, and discoloured, silicious, open, small imbedded particles of 
slate ; cuts fairly well. 

Shippool. Kinsale.—Yellow-shaded green ; semi-granular and 
quartzose; slightly calcareous. 

Baillymartel. Kinsale.—Stones varying; best, yellow, fine- 
grained, compact, but slightly micaceous. 

Coat-mrasuRES (Ba/linaquila. South-west of Dromina).—A 
quarry of good flags, and quarries of sandstone. 


Or 


Kinanan—On Irish Arenaccous Rocks. Ral 


LISTS AND NOTES BY A. §. WILLIAMS, BOARD OF WORKS. 


(The localities are in the Devonian and Carboniferous.) 


Baltimore. Hull back of Coast-guard Station.— 

Light-grey. National school and residence. Fit for 
any description of work, and improves on exposure. Has 
been used in some of the ancient structures near this place. 
(Vide page 542. Stones of Sherkin Island and the main- 
land to the eastward.) 


Ballyalley. Seven miles from Skibbereen.— 
Grey grit. Coast-guard Station. This stone, if ob- 
tained at a reasonable depth from the surface, is fit almost 
for any sort of work. 


Rosscarbery. ‘The Beamish quarries, west of the town.— 
Brownish and yellowish. National Schools, Rosscar- 
bery. Good stone for ordinary work, and, if selected, fit 
for dressings. Can be raised in very large scantling. 


Onion Hall.— 
Blue argillaceous and slaty grit; very hard. Union 
Hall and Glebe. Only suitable for rubble and walling. 


Ballydonegan. Twelve miles west of Bearhaven.— 
Brownish. Coast-guard Station. Stone hardens on 
exposure. Is fit for any description of work. 


Lehanemore. Sixteen miles westward of Bearhaven.— 


Grey grit. National Schools. Only used in rubble 
and walling. Very durable, but not fit for chiselling. 


Derrincorrin. Seventeen miles north-westward of Bantry.— 
Brown. National Schools. Can be raised in fair- 
sized blocks. Very durable, but not suitable for dressed or 
chiselled work. 


046 Scientific Proceedings, Royal Dublin Society. 


Dromore. Hight miles westward of Drimoleague.— 
Grey grit. National Schools. Suitable for building, 
or can be raised in large dimensions, suitable for flagging. 
Can be dressed for quoins, and improves on exposure. 


Dunnycove Bay. South of Clonakilty.— 

Liver coloured. Ardfield National School, six miles. 
from Clonakilty. Used in walling and rubble, window 
and door-sills of limestone, which is usual in this neigh- 
bourhood. 


Timoleague.— 
Blueish, flaggy grit. National School, Timoleague. 
Never used except in dressing for opes and sills. It is 
easily raised in blocks of large scantling; well suited for 
piers or other harbour works. 


Borleigh. Hight miles from Bandon.— 
Grey to brownish sandstone. School and residence, 
Borleigh. This quarry is historical, the stone having been 
used in the Timoleague Abbey and other ancient struc- 
tures. 


Rahavoon. Six miles from Bandon.— 
Brown. National Schools. Very hard ferriferous vein ; 
only fit for walling. 


Milistreet.— 
Reddish-yellow. Millstreet Dispensary. A superior 
building stone, suitable for any description of cut-stone 
purposes ; largely used in church work. 


Dromagh.—— 
Grey grit (Coal-measures?). Dromagh Glebe. An ex- 
cellent stone, suitable for all dressed work of small scantling, 
as it cannot be obtained in large dimensions. 


Lismore. Six miles from Kanturk.— 

Brown. National School and residence. Hard stone ; 
similar stone very common in the county, and used for 
walling and rubble, the quoins and sills being procured 
from the Kanturk and Keelin quarries. 


Kinanan—On Irish Arenaceous Rocks. 547 


Boherbwe. Hight miles from Kanturk.— 


Brown. Dispensary. Stone similar to that at Lis- 
more. Dressings from Kanturk and Keelin quarries. 


Inchageela. Quarries in adjoining hills.— 


Grey and greenish; flagey. Inchageela National 
School and Kilmichael (Tareton) Glebe. Stone hard; with 
difficulty can be chiselled, but is not fit for dressing. 


Sanp anD GRAvEL.—Good sand for building purposes is pro- 
curable in various places in the different valleys. Pit sand occurs 
in the neighbourhood of Cork and Macroom ; while good river sand 
is obtained five miles from Bantry, in the River Snave; in the 
Lee, three miles from Cork; in various places along the Bandon 
river and the Blackwater; in the Islin river, near Skibbereen ; 
and in various streams. In numerous places along the coast there 
is good sea sand. 

In Bantry and the neighbouring bays there are accumulations 
of rich shell sand, or rather coralline sand. Before 1848 there was a 
large trade in these sands for agricultural purposes, it supporting 
a large fleet of boats, which dredged the sand, and brought it into 
Bantry and the other quays, from whence it was carted inland, 
even over the hills into the Co. Limerick. At the same time there 
was also a fleet of 35-ton lighters at Youghal, engaged in similar 
shell sand dredging. 

Good pit sand occurs about a mile from the Blarney Railway 
Station. It is very generally used in the Co. Cork. 

Near Mitchelstown, on the Kingston estate, is excellent pit 
sand ; also river sand in the River Funcheon. 

Near Glanworth, at Dunmahon, very superior pit sand occurs 
on Mr. Dilworth’s farm. 

At Ballydonegan Bay there is a peculiar sand, due to the 
crushing of the copper ore. Previous to the Allihies mines being 
worked, there was no holding-ground for anchors in the bay, and 
at the mouth of the river there was a gravelly beach. Now there 
is good holding-ground in the bay and a sandy beach. 

For moulding purposes in the foundries the sand is principally 
procured from Belfast (valley of the Lagan) ; but some of an infe- 
rior quality is got in the neighbourhood of Bishopstown. 


SCIEN. PROC. R.D.S., VOL. V., PT. VII. py 12) 


048 Scientific Proceedings, Royal Dublin Society. 


Gxiass.—In Cork there were two large glass-houses for the 
manufacture of flint-glass, with extensive premises for cutting, 
engraving, &c., attached to each. One ceased to exist about 1835, 
and the other before 1840. The sand used seems to have been 
imported. 


DONEGAL.* 

For the most part this county is occupied by granitic, eneissose, 
and schistose rocks. ‘These, from recent researches, are known to 
belong to two distinct geological groups, the older probably repre- 
senting rocks equivalent to the Cambrian and the Arenig, while 
the later represent the Ordovician and perhaps, in part, the Llan- 
dovery or May Hill Sandstone. On these older rocks, in places, 
such as at Ballymastocker Bay, Fanad; Muff, Lough Foyle; along 
the mearing of the Co. Fermanagh, to the northward of Pettigoe ; 
and in the neighbourhoods of Killybeg, Donegal, and Bally- 
shannon, there are Carboniferous rocks of greater or less extent, 
that in Fanad being a mere patch. 

CamMBRIAN AND ARENIG.—The sandstones, grits, and quartz- 
rocks which occur in the strata supposed to represent these geological 
groups are now all more or less altered into quartzytes, gneiss, 
and foliated granite. But some of the quartzytes, especially some 
of those in the gneiss and foliated granite, are even-bedded, and, 
when also regularly jointed, they are excellent material for walls 
and such like; but they will not bear dressing. Many of the 
altered quartz-rocks are splintery. In places, however, they are 
massive, and capable of being raised in large blocks; and, under 
such circumstances, they are more or less suitable for foundations, 
sea walls, and other heavy work. 

OrpDovicIAN AND LLANDOVERY (?).—The sandstones and quartz- 

‘rocks which are supposed to belong to the rocks equivalent to some 
of these groups are, in a great measure, altered into quartzyte. 
Some, however, are unaltered or very little altered, as sandstones 
occur in the Rathmullen district, between the ridge called the 
Devil’s Backbone and Lough Swilly; also in the barony of 
Raphoe, south of Lough and Glen Swilly. In the Rathmullen 
district some of these stones dress fairly well, but are liable to 
discolour. ‘Those in Creeve Mountain, about three miles north- 

* See ‘‘ Notes added in the Press.” 


Kinanan—On Irish Arenaceous Rocks. 549 


west of Rathmullen, have been used for facing in Ramelton. 
In the valley about a mile south of Creeve Mountain, in the 
townland of Oughterlinn, there are flags; these are good, hard, 
and silicious, and can be raised of large dimensions—12 feet long 
by a width of 4 to 6 feet. ‘They have been usedin Ramelton; but 
the place is very inaccessible, the road being very bad. ‘To the 
north of Rathmullen, in places near Lough Swilly, there are also 
flags that have been worked for local purposes, especially in the 
neighbourhood of Long Lough. 

In the quartzyte range of Knockalla some of the quartzytes 
are thin-bedded. They are silicious and hard, and appear as if 
they could be raised in marketable sizes. ‘These, as yet, have not 
been opened on; but, if they could be obtained of sufficient sizes, 
they should be valuable. Up to the present the place has been 
very inaccessible; but as a pier has been erected in Ballymastockan 
Bay, at Croaghros, they are now near a port. At the opposite 
side of Lough Swilly, in Dysertegney, Inishowen, these beds are 
worked, and produce good flags, that ought to be more utilized 
than at present. 

There are also veins of more or less similar flags in the north 
of the county, near Crossroad and Dunfanaghy, which are locally 
used. 


[The age of the rocks in the north of Donegal is still undetermined. For some 
reasons they might be supposed to belong to the later groups, while there are also 
reasons for supposing they are portions of the older. The geology, however, here- 
abouts is so complicated, the younger and older strata being folded in sharp inverted 
curyes, that it is quite possible that their exact age will never be satisfactorily known. | 


In the barony of Raphoe none of the sandstones have been 
considered specially suitable for cut-stone purposes, although they 
are very useful for walls. Those which can be raised in large blocks 
are good for coarse and heavy work, suck as foundations and the 
like. In a few quarries, however, the stones have been used for 
dressed work, and they cut fairly well. ‘They, however, are liable 
to discolour. 

Muckish. ‘Three miles from Dunfanaghy.—Quartzyte; open 
and porous; pure white; semi-crystalline ; slightly foliated ; very 
slightly calcareous. 

Kinclevin. Nearly a mile from Dunfanaghy.— White quartzyte. 


with minute divisions of mica. 
G2) 92 


550 Scientific Proceedings, Royal Dublin Society. 


Errarooey. Near Crossroads.— Yellowish ; improves in colour on 
exposure; silicious; durable; free-working ; can be plugged, and 
hammers well; can be raised in long scantling, and is capable of 
long bearings; was used in the foundations and coping-stones of 
Myra Bridge and in the Roman Catholic Church and School-house,. 
Crossroads. ‘The vein extends eastward and westward. 

Minnagran. Seven miles from Glenties.—Here the rocks are: 
very much altered, and appear to be more of a gneiss than a 
quartzyte. The stone is used for dressed work, and in the vicinity 
it is called “millstone.” 

At Carrick, eight miles northward of Milford, and in places to: 
the westward, there is a reddish, porous quartzyte, that squares 
fairly well, but will not cut. It is a good building stone, and 
was largely used in the building of Manorvaughan, or Mulroy 
House. It keeps its colour, and has a good effect. Locally it 
is called “red granite.” 

Killyclug. North of the Letterkenny Waterworks.—Quartzose 
sandstone; rises in long massive flags; capable of long bearings ; 
good for rough building, such as lintel and posts in farm buildings. 

CarponirERous.—In the already mentioned Carboniferous: 
outlier at Ballymastoker Bay, Fanad, there are red conglomerates 
and sandstones. The first were formerly used, to a small extent, 
to be wrought into flax-crushers, while the sandstones were used 
for local purposes. 

Tn the parish of Muff, on the west of Lough Foyle, and to the 
north of Derry, the rocks consist principally of reddish sandstones. 
and conglomerates, which are used for local purposes. 

To the south-east of the county, margining the Co. Fermanagh, 
that is, northward of Pettigoe, there are in places stones of yellow- 
_ ish-grey shades. At Lettercrann, about three miles from Pettigoe, 
were procured the stones for the stations on the Enniskillen and 
Bundoran Railway. , 

In this tract some of the stones are specially suited for flax- 
crushers and millstones, and forty or fifty years ago many were. 
made. 

In the Carboniferous rocks, near Donegal and Ballyshannon, 
some of the sandstones are of good characters. They are from 
pale cream-colour and nearly white to reddish and purplish ; from 
very fine to coarse conglomerates. Formerly from this county 


Kinanan— On Irish Arenaceous Rocks. 561 


there was a large trade in flax-crushers, they being sent on carts 
into the other portions of Donegal and the neighbouring coun- 
ties, or shipped from Donegal town to different places along the 
coast-line. 

This trade seems to have been very short-lived. Formerly 
flax was kiln-dried, the old disused kilns being scattered over the 
county. In general, the inhabitants cannot tell you what they 
were for; a few, however, state that in their grandfather’s time, 
some sixty or seventy years ago, before the stone-crushers were 
invented, all the flax was “beetled,” that is, crushed by hand 
with wooden beetles, and, before doing so, it had to be kiln-dried. 
The kiln-drying ceased when the crushers came into fashion; and 
the trade in the latter appears to have died out some ten or fifteen 
years ago, partly on account of the failure in the flax crops, 
partly because mills were erected in which the flax was crushed, 
and partly because, by some of the new modes of obtaining the 
fibre, the flax does not require to be crushed, but is sold in the 
unbroken state. The unsold flax-crushers are to be seen every- 
where about the town of Donegal; lying in heaps, as if some 
giants had been playing a game of quoits. They are now put to 
innumerable uses. 

The stones near Mount Charles have lately been greatly brought 
into notice by the Drumkeelan stone being selected for the new 
Museum and Library, Leinster House, Dublin. Wilkinson, in 
1845, stated that the best stone is yellowish-grey, or pale cream- 
colour, free, felspathic, slightly micaceous, with a silicious ferri- 
ferous cement. Of it Mr. Cockburn states:—“It is good and 
durable, but hard to work ; and has been used in the dressing, 
Town Hall, Sligo; also for quoins and dressing, with other sand- 
stones, in the Killybegs Coast-Guard Station. ‘The Provincial 
Bank, Ballyshannon, was contracted to have been built with this 
stone; but, when half up, the supply of good materials seems to 
have failed, the upper portion being stones from Dungiven, Co. 
Londonderry ”’ (see Dungiven, p. 583). 

Altito. Three miles from Donegal.—Dirty yellow. Varying 
from granular to conglomeritic ; very quartzose; semi-crystalline ; 
hard; cement felsphatic. Formerly largely wrought into mill- 
stones and flax-crushers; also heavy kerbing-stones. Used for 
ashlars in Lough Hske Castle. 


002 Scientifie Proceedings, Royal Dublin Society. 


Drumkeelan. Three miles from Mount Charles Pier.—Creamy, 
to nearly white; felspathie; slightly micaceous, with slightly cal- 
careous cement. Dresses and cuts well; hardens on exposure. 
Good strong flags can be obtained here; used in the town of 
Donegal. Three thousand tons of this stone have lately been 
shipped by the Messrs. Beckett, to build the Museum and Library 
for the Science and Art Department, Leinster House, Dublin. 

Beauwin.—Used in Killybegs Coast-Guard Station for boat- 
house and slip. ‘Coarse and uneven in grain, with large quartz 
pebbles. There are some beds of a fine texture and a beautiful 
tint in this place, but there is no regular quarry, the stones being 
raised off the surface, and where they can be had with least trou- 
ble” (J. Cockburn). 

Kildoney. Four miles from Ballyshannon.— White, micaceous, 
silicious grains, with argillaceous silicious cement. This stone 
dresses and cuts fairly well, and is very durable; used for wall- 
facing. It is near the sea, and therefore easy of transport, but is 
not thought as much of as the stones from the Dog’s Mountain. 

[In this neighbourhood, in the cliff overhanging the sea, is an anthracite, about 


7 inches thick. In boring in search of this coal, a sort of emery was struck, 12 feet 
from the surface. | 


Dog’s Mountain. Fifteen miles from Ballyshannon.—Light 
yellow, ferruginous, fine-grained, slightly micaceous; works freely 
and well. Excellent flagging (was used at the Parish Church, 
Ballyshannon) can be obtained here. 

To the south of Bundoran, in the ridge of Calp sandstone, 
partly in this, and partly in the adjoining counties, is excellent 
freestone, which was largely used in the buildings in the town. 

SAND AND GraveL.—Near the top of the north face of Muckish. 
‘occurs a very superior silicious sand for glass-making. A little of 
this at the beginning of the century was shipped to Belfast and 
Scotland. The place, however, is very inaccessible, and the cost 
of getting was so great, that it was undersold in the markets by 
foreign sand. 

[£2 a-ton is what it was then sold at. It is coarser-grained than the Belgian sand,. 


but of a better quality. The best Belgian sand at the present time can be delivered in. 
Dublin for 15s. a-ton.] 


The Muckish sand occurs as a disintegrated bed in quartzyte. 


Kinanan—On Irish Arenaceous Rocks. 553 


Only the washed and weathered-out crop can be seen and ex- 
amined. How far it extends into the hill, and its quality when 
followed in, cannot be known unless a level was driven in on the 
bed. 

[Lewis states there is a similar sand near Lough Salt. This, however, after 
minute inquiry, I cannot find ; it seems to be unknown. ] 

Kane points out that, “In several of the bays of Donegal the 
sand thrown up by the Atlantic storms is of great purity, and 
fully equal to that in ordinary use amongst glass manufacturers.”’ 

Donegal sand was used at the Glass Bottle Works, Ringsend, 
Dublin, “and found very good;” but owing to the price having 
risen, the use of it was discontinued. 

In some of the streams westward and south-east of Letter- 
kenny, there are sands also due to the disintegration of quartzyte 
or sandstone in situ. Those known are, however, more or less im- 
pregnated with iron. 

A rather quartzose sand occurs along the railway from Letter- 
kenny to Derry, at Ballyboe and Monclink. The sand from the 
latter was largely used as ballast on the line. 

Pit sand for mortar in general is not very plentiful; it how- 
ever occurs in Inishowen and near Milford; while there is inferior 
pit sand in the neighbourhood of Dunfanaghy and Falcarrah. A 
very good greenish pit sand occurs a little north-east of Kilma- 
crennan. A fine sharp sand occurs in small hills in Tullybeg, east 
of Lough Fern; while about two miles westward of Rathmelton, 
in the valley of the Leanane, in small esker-like ridges, there is a 
clayey sand, used in Ramelton. River sand from the streams 
and rivers is, however, in general good; excellent sand for use in 
Donegal being found in the Dunmurry and Legacorry streams. 
Other good river sands occur near Glenties; above Letterkenny, in 
the Swilly ; in inexhaustible quantity in the Foyle, south of St. 
Johnstown, used in Derry; in the Finn river, at Lifford ; and in 
various other places. Good sea sand is got in places along the 
coast-line. There are on the west and north coasts very extensive 
dunes and tracts of Molian sand. 

“ Close to the village of Muff, fine sharp white free sand occurs ; 
used extensively in the neighbourhood and Derry (six miles distant) 
for scouring steps and such like. In this neighbourhood some of 
the sandstones are very soft and friable.” (A. IC. Stewart.) 


554 Scientific Proceedings, Royal Dublin Society. 


DOWN. 


Rocks of Ordovician age occupy the major portion of this 
county; but in these to the southward, among the Mourne Moun- 
tains, in the vicinity of Carlingford Lough, are intrudes of 
granite and other Exotic rocks. Two very small tracts of Car- 
boniferous rocks occur, one on the margin of Carlingford Lough, 
and the other in the vicinity of Castle-espie, at the north end of 
Strangford Lough; while to the north-west and north, in the 
valley of the Lagan, northward of Comber, and in the neighbour- 
hood of Newtownards, are Triassic. In the valley of the Lagan, 
over the Trias, are other Mesozoic rocks, and the Locene (?) 
dolerytes, with their accompanying basal beds. 

Orpovictan.—The various grits that occur in places in the 
rocks of this group seem to be only used for local purposes, as in 
the area there is no quarry of note. In the district the slate rocks 
are usually used for rubble work; and granite, or Trias sandstone, 
for groins, dressings, and other cut-stone purposes. At Ballygowan 
there is a stone used in the National School, which Mr. Grey 
reports as “very hard, durable, and dark-coloured—nearly black.” 

Near the “ Stone Circle,” Millan Bay, and to the south-west of 
Slievenagriddle, flags of large size can be obtained. 

Triassic.—In the quarries along the valley of the Lagan the 
stone, nearly invariably, is of a deep-red, or brick-colour, and more 
or less soft and argillaceous. It has been largely used for local 
purposes, especially for the bridges of the Ulster (now the Great 
Northern) Railway. There is a considerable quarry at Kalvarlin, 
near Moira. 

To the north of the county, at Scrabo Hill, near Newtownards, 
there is a better class of stone. Here there are different quarries, 
in which the stone varies greatly in colour and quality, there being 
shades of grey, yellow, and red; some are argillaceous, others 
silicious, while they may he friable, or have concealed joints or 
vests ; therefore they have to be selected with great care if good 
and uniform work is required. 


[Blasting is too prevalent in this quarry. Good stones, with a little extra trouble, 
might be raised by the crowbar and wedge, while, if raised with powder, they are 


KinauaAn—On Trish Arenaceous Rocks. 550 


shaken, and more or less valueless. This remark is not only applicable here, but also 
in various other sandstone quarries, where the character of the stone is spoilt by the 
mode of raising the blocks. | 


All the stones are free-working, and, if raised with care, and 
well-selected, are durable. Formerly they were very extensively 
used in Belfast, but of late years they have been cut out by a very 
general introduction of Scotch stone. 

These quarries also supply good strong flags, from 2°5 to 3 in. 
thick. 

Newtownards is built nearly solely from these quarries; the 
large Town Hall, as pointed out by Wilkinson, displaying some 
good work. 

The Scrabo stones have been used in Belfast, in the Albert 
Memorial, St. Enoch, Fortwilliam, Sinclair’s, Elmwood, and 
Donegal-street churches; the Academy, in the offices of Robinson 
and Hewits, and the warehouse of Robinson and Cleaver, the last 
two being from the Glebe Quarry. They were also used in Stor- 
mount Castle and the Model School and Strain Church, New- 
townards. Mr. William Gray, M.R.I.A., says of the stone, that 
it is “very variable in colour and texture, stands fairly well 
when selected and set on bed, but tilted on edge it will not stand. 
It works freely, and, as a rule, is of a light-brown colour.” And 
of the “Glebe Quarry” :—‘“It yields a light-coloured stone, of 
very even texture, and good colour. It is soft, but stands fairly 
well, and makes a good building stone. 

Dundonald. Four miles from Comber :—Red ; fine-grained ; 
like the Dumfries stone (Scotch), and has been used for it. The 
quarry does not yield a very large quantity. Has been used in 
Belfast in the Spencer basin ; cottages and villas at Knock ; Preston, 
Smith & Co.’s Warehouse, &e. (Wilkam Gray.) 

The principal Irish sandstones used in Belfast are from 
the Scrabo and Dundonald quarries, Co. Down; Dungiven, Co. 
Londonderry; Ballycastle, Co. Antrim; Cookstown, and different 
quarries near Dungannon, Co. Tyrone; those from Ranturly, 
Mullaganagh, Bloomhill, and Carlan being most preferred. 

Sanp AND GraveL.—Good pit sand occurs in the valley of the 
Bann, also at Saul, between three and four miles from Down- 
patrick, in the neighbourhood of Newtownards, and in other places. 
There is good river sand in various places along the streams and 


556 Scientific Proceedings, Royal Dublin Society. 


rivers ; while near Kilkeel and Newry the sea sand is also good. 
Red sand suitable for foundry purposes, and exported from Belfast 
to Dublin, Cork, &c., is procured in the valley of the Lagan. 

Frint-Guass was formerly largely manufactured in Newry. 
Although this was in existence in 1840, yet now it seems hard to 
get information about it. 

There was a second manufactory at Ballymacarret, a suburb of 
Belfast. To this, at the beginning of the century, a few cargoes 
of Muckish sand—Ards, Co. Donegal—was brought, and found to 
be very superior; but the expense of getting the sand, and the 
consequent high price when delivered, drove it out of the market. 


DUBLIN.* 


There are arenaceous rocks among the Ordovicians to the north 
and south-west of the county, the latter in part being metamor- 
phosed. In the Rathmichael Round Tower, quartz-rock and clay- 
slate were used ; but the masonry is very rude. As beds of limited 
thickness in the calp division of the Carboniferous there are argil- 
laceous sandstones, and there are also sandstones in the Lower Coal- 
measures. 

CaRrBonrIFERouS.—In some of the calp quarries there are ar- 
gillaceous calcareous sandstones, or arenaceous limestones, capable 
of being raised in large blocks, and suitable for heavy work, such as. 
foundations, for which they have been extensively used. In some 
quarries they are thin-bedded, and give good flags. ‘This was 
specially the case in one set of beds in the old “ Windmill 
Quarry,’ Rathgar, and some years ago there was an extensive 
trade in them. As, however, the “ overbaring,” and conse- 
. quently the expenses of the quarry, increased, the trade dropped. 

In the north division of the county there are patches of Lower 
Coal-measure rocks. In these there are some grits and sandstones ; 
but although some of them are fair stones, none of them appear to 
have been used, except for local purposes. 

In the city of Dublin sandstone is largely displayed in the 
public buildings; but none of the cut stone seems to have been 
obtained in the county, while most of it, especially in the buildings 
during the last century, and in the beginning of the present, is 


* See *‘ Notes added in the Press.” 


Kinanan—On Irish Arenaceous Rocks. aoe 


English stone. Portland stone, according to Wilkinson, was used 
in the following structures :—Old Parliament House, now called 
the Bank of Ireland; Trinity College, except the Provost’s House, 
for which the stone was procured in the neighbourhood of Liver- 
pool; Royal Exchange; Post Office; Rotundo; King’s Inns; 
Law Courts; Custom House; the dressings at the Castle; the 
statue, Nelson’s Pillar; St. George’s Church; St. Thomas’s. 
Church ; Roman Catholic Cathedral, Marlborough-street. It has 
stood well, but is much discoloured. For some years past it has 
fallen off in demand. Its present price in Dublin is two shillings 
per cubic foot, and one shilling per square foot for working. 

From information procured by Mr. R. Clarke we learn the 
following as to buildings erected since Wilkinson wrote :— 

“‘ Subsequently oolite limestone, or Bathstone, was in demand, 
which may be here mentioned, although somewhat out of place. At 
present there are four qualities in the market, which are delivered at 
two shillings and two pence per cubic foot, and dressed at one shilling 
per square foot. It has been used in the following offices during 
the last twenty-five years :—Provincial Bank, College-street ; 
Guinness’s mansion, Stephen’s-green ; Standard Life Assurance,, 
Sackville-street ; Trinity Chambers, Dame-street; Royal Insur- 
ance (?), Dame-street; Crown Life Insurance (?), Dame-street ; 
Commercial Union Assurance, College-green; Law Life Insur- 
ance, Sackyille-street ; and Lancashire Insurance, Sackville-street. 

“‘Caen-stone is used for finer kinds of work than either. the 
Portland or Bath, such as all kinds of inside work. 

“Drumfries stone has been used in many of the insurance office 
buildings. 

“Runcorn red was also used in many of the insurance companies’ 
offices as well as in other structures, principally for bands to set off 
lighter sandstones, or granite. It, however, isnot durable, as may be 
seen in the Augustinian Friary Church, John- and Thomas-streets, 
where the Runcorn stone has decayed so rapidly, that although 
only built twelve years, it is now being taken down and replaced 
by granite. 

“‘ Furness Abbey red stone has also been imported. 

“Of late red sandstone has been brought from Dundonald, near: 
Comber, Co. Down, and has been largely used in building the new 
portion of the Great Northern Railway Terminus, Amiens-street. 


508 Scientific Proceedings, Royal Dublin Society. 


This stone has a good reputation in Belfast, where it has been 
largely used.” | 

“Dungannon stone,” from Mullaganagh, or the Ranfurly 
quarry, Co. Tyrone, was used in the new additions to the Royal 
University, and has held its colour well. 

The creamy sandstone from Mount Charles, Co. Donegal, has 
been used extensively in the new building for the Science and Art 
Department, Leinster House. This seems to be the first place of 
note in Dublin where it has been tried. 

SanD AND GraveL.—In this area, in the ground that is below 
the two hundred and fifty feet contour line, but more especially 
below the one hundred feet contour line, there are large accumula- 
tions of sand and gravel. In some localities, however, especially 
those below the lower line, the gravel and sand has extensively 
been worked out for road and building purposes, large areas being 
cleared of the accumulations that once existed, so that anyone now 
mapping the edges of the gravel terraces would draw lines quite 
different to those of the margins of the original sea-beaches. This 
is specially the case in the tract between Booterstown and Dublin. 
As, however, these sands and gravels are so prevalent in the county, 
good pit sand can be procured in numerous places. 

The Drift Cliffs of Killiney Bay are for a large part composed 
of these gravels, and the sands, the washing from the cliffs, have 
within the last thirty or forty years come into great repute, so 
much so, that now, almost as fast as the beaches form, they 
are carted away, to the great detriment of the owners of the ad- 
jacent land, as their land, being deprived of its natural protection, 
is rapidly carried away by the sea. This removal of the sand, and 
consequent waste of land, has led to various lawsuits. 


[Within the last forty years, since the great trade in Killiney gravel has been in- 
stituted, the cliffs, from a want of their natural protection, are receding backwards at 
a rate of at least one foot every year; while, in certain places, the destruction is even 
much more extensive, exceeding two or even three feet per annum. From careful 
calculation made on the coast of Wexford, where the natural waste of the drift-cliffs 
at the present day is greater than deere in Ireland, the average waste is one foot 
per annum, the excessive waste in two or three other places being three feet per annum, 
and in one or two as much as four feet and five feet. 

These wastes on the coast-line are very interesting, some being evidently due to 
artificial structures. Thus, the intaking of the north and south slopes in the Slaney lagoon 
(Wexford Harbour) changed not only the character of the Dodder Bank, at the mouth of 
the lagoon, but also that of the Lucifer Shoal, six miles off its entrance. And these 


Kinauan—On Irish Arenaceous Rocks. 509 


changes in the banks have affected the infringement of the currents on the north-= 
ward coast, so that since these intakes have been made the coast-line of the North 
Bay, that is between Wexford and Cahore, has been much more rapidly denuded. On 
the other hand, on the South Bay, or as it is now called on the recent charts, Bally - 
geary Bay, the erection of the new pier at Ballygeary has quite changed the features 
of the shores of the bay, by accumulating fulls at the base of the cliffs that previously 
were rapidly being denudedaway. ‘This is especially the case between Ballygeary Pier 
and Greenore, where there are now ‘‘ fulls’’ and apparently permanent beaches in places. 
that ten years ago showed a clean-washed rock surface up to the base of the drift-cliff ; 
these beach accumulations covering up most interesting geological sections, that pro- 
bably will never be seen again until Ballygeary Pier has disappeared. On the south 
coast of Wexford the Ballyteigue flats were intaken; here also the change has had 
great effect, as since the intake the landimmediately west of the entrance to the lagoon 
has been rapidly denuded away ; but further westward, in the vicinity of Cullenstown, 
a foreshore has grown out. If it were necessary, various other cases could be enumerated 
where there are also changes due to human agencies. In other places changes are 
taking place from unknown and hard-to-be-explained natural causes, fulls forming or 
being cut out for no apparent reason. The most remarkable case that has come under 
my observation is the tidal effect on the middle island of Arran, at the entrance of 
Galway Bay, where the effects of the tidal currents of late years are perfectly different 
to those a quarter of a century ago, while there seems no apparent reason for a 
change. | 


Good pit sand for building purposes can be obtained at Knock- 
more, Valley of Diamonds, and Ballywaltrim, Dargle-road, Bray ; 
also at the Moat, Old Connaught. ‘The last isa very superior 
sand, very clean and sharp (silicious). It is in Lord Plunket’s 
demesne, and is not for sale, but is used”by special permission for 
any very particular stucco plastering rough-cut work. There is no 
sand equal to it, certainly none to surpass it, in the Co. Dublin. 
(ZT. B. Grierson.) The foundry sand (red) used in Dublin is im- 
ported from Liverpool and Belfast, costing, delivered, about 15s. 
per ton. At one time good sand came from Co. Cork, but it does 
not seem to be used now. 

Guass formerly was largely manufactured’; but in 1886 there 
were only two flint glass and seven glass bottle manufacturers. 
Through Mr. White of Dublin we learn that at the Ringsend Bottle 
Co.’s works the common bottle glass is “made by the fusion of 
the following materials: sand, from the adjoining Sandymount 
strand; blue clay, from Sutton strand ; waste lime, from Bewley 
and Draper’s chemical works ; kelp waste ; broken red tiles, to give 
body; rock salt, from Drogheda; refuse manganese ; a small quan- 
tity of coarse fluor-spar, and oyster shells. 

“The materials now used for the finer glass are Antwerp sand, 


560 Scientific Proceedings, Royal Dublin Society. 


French chalk, carbonate of soda, oxide of manganese, fluor-spar, 
and arsenic. 

“Ground granite was used formerly for the finer varieties of 
glass, but was discontinued in consequence of the high temperature 
required for its fusion. Donegal sand was also used, and was 
found very good; but, owing to the price having risen, the use of 
it was discontinued.” 


FERMANAGH. 


To the north-west of the county there is a small tract of meta- 
morphic rocks coming in from those of the Co. Donegal. They 
are probably the equivalent of the Arenig, or perhaps Cambrian. 
East of Lower (North) Lough Erne are Silurian of the “ Lower 
‘Old Red Sandstone” type. The rest of the area is occupied by 
Carboniferous rocks. 

The age of the Carboniferous rocks occupying the tract at the 
south-east of the county, of which the highest summits are Slieve- 
beagh (1255 feet) and Carnmore (1034 feet), is disputed. Griffith - 
considered them “‘ Ca/p,” or the middle group in the Limestone ; 
John Kelly, whose opinion is adopted by Dr. Hull, calls them 
Coal-measures ; while Baily states the fossils prove them to be 
Lower Carboniferous. A8 previously stated, we believe that they 
are Coal-measures, and will refer to the lower sandstones as “ Fer- 
managh sandstone.” (See Introduction, page 524.) 

West of Lower Lough Erne, extending 8. 8. H. from Lough 
Erne, past Derrygonnell to the Arney river, is another tract of 
Calp ; while north-east of Lower Lough Erne, in the Kish district, 
the rocks are of the “ Ulster Calp type,” capped to the south-west 
of Kish by a small tract of “ Fermanagh sandstone” (Lower Coal- 
" measures). | 

In the western part of the county are Coal-measures, part of 
the ConnaucHt CoaL-FIELD, which, as previously mentioned, 
extends into the province of Ulster. 

Orpovician.—The grits of this group can be used for walling 
and rough purposes; but, as there are usually better stones in the 
vicinity, they are only very locally used. 

SirurtAn.—The sandstones, which are in the majority in the 
mass, are generally shades of red, brown, and purple, although 


Kinanan—On Irish Arenaceous Rocks. 561 


some are yellowish or variegated. In many of them there are 
argillaceous or shale spots and specks. At Lisbellaw, in connexion 
with the exposure of Ordovicians, a massive conglomerate abruptly 
comes in, as if it had been a shingle mass against a head, that 
acted as a groyne at the end of an ancient strand. The pebbles in 
it are remarkably hard, and are much used for road metal. The 
evident circumstances under which the “ Lisbellaw conglomerate” 
accumulated have been given in a Paper on this subject (page 504, 
ante). 

These Silurian sandstones are in general too coarse for dressed 
work, though well adapted for ordinary or coarse work. ‘The finer 
kind was extensively used in Necarn Castle, near Irvine—or 
Lowtherstown—the dressing being the Calp sandstone from Lis- 
naskea. At Castle Archdall, however, in the same neighbourhood, 
it was used for the quois and dressing, while the walling is an 
impure limestone. 

In Ardlogher Quarry, near Irvinestown, the stone varies, being 
shades of reddish-grey. It is granular, semi-crystalline, hard, 
‘compact, and slightly calcareous. Lower beds mahogany-red to 
red; argillaceous; laminated and micaceous ; works fairly well. 

Mullaghfarm. Four miles from Irvinestown.—Brittle and hard 
to work; used for quoins and common dressing. 

Kerlish. TWileven miles from Irvinestown.—Various; generally 
coarse, conglomeritic, quartz-grain, felspathic cement, and slightly 
ferriferous ; others finer in texture. 

CarBoniFeRous.—In the disputed area of Slievebeagh dis- 
trict, here described as Fermanagh sandstone, there are some 
noted quarries. In the neighbourhood of Lisnaskea most of the 
stones are creamy, yellowish, or slightly greyish, good, free- 
working, and have been extensively used in Lisnaskea, besides 
other places in this and the neighbouring counties, such as Irvines- 
town, Enniskillen, Clones, Monaghan, and Newtownbutler. They 
do not, however, seem to have gone into the Dublin or other 
distant markets, although some of them are well worthy of notice. 
Stones from these quarries were used as quoins and dressing at 
Crom Castle, and at Necarn, near Irvinestown, for ornamental 
work. 

Tannyby. Near Lisnaskea.— Yellowish-white to reddish-grey ; 
finely silicious-grained ; felspathic cement; ferriferous spots; free- 


562 Scientific Proceedings, Royal Dublin Society. 


working ; many houses in Clones and Lisnaskea are built of this: 
stone; but the quarry seems to be now closed. 

Slush Hill. Two miles from Lisnaskea.—Greyish-white and 
yellowish ; silicious-grained; scarcely any cement; ferriferous: 
stains ; some beds very friable; easily worked. Some fifty years. 
ago this was the principal sandstone used in Enniskillen, Clones, 
and Lowtherstown (now Irvinestown). Dartry mansion, Co. 
Monaghan, and Farnham, Co. Cavan, were built of stone pro- 
cured here. Now, however, the quarry is not worked, on account 
of the “ overbaring.”’ 

Kilturk, or Mount. Between two and three miles from Lis- 
naskea.—A somewhat similar stone; splits into long scantlings. 
Nearly all the gate-posts and the cut stones for the buildings of the- 
Great Northern Railway westward of Dundalk were procured from 
this quarry. 

Knocknalossett. Seven miles from Lisnaskea.—The stones for 
Monaghan College and smaller buildings were procured here. 

Crocknagowan. 'Two miles from Lisnaskea.—Stones used in Pres= 
byterian churches, Belturbet and Aughnamullan, Co. Monaghan, 
Clones Gas Works, and Tempo House; also wrought into tomb- 
stones. 

Eshbralby. Three miles from Lisnaskea.—Stones used in Inish- 
more Hall, and for pillars and dressing in Crom Castle, and in the. 
new work, Hnniskillen Church. It is also wrought into tombstones, 
and some of the beds into scythe stones. 

Altnabrock, or Aughnabrock. Near Lisnaskea.—Clean, fine- 
grained, and massive; Ulster Banks, Enniskillen, Lisnaskea, and 
Clones; seems to be much sought after at the present time. . 

Corraghy, or Elderwood. Three miles from Brookborough.—Not 
in repute for cut-stone purposes. 

Carnmore.— Pebbly, silicious sandstone; good; hardens on 
exposure; easily worked when first raised. ‘This stone formerly 
was extensively wrought into mill-stones and flax-crushers before 
these industries declined. 

To the north-east of Lough Erne, in the Calp of the “ Ulster 
type”’ of the Kesh district, there are good stones to be procured in 
Inishbo (Cow Island) in the north portion of the lake, and in 
different places north-east of Kesh. According to Mr. Plunkett, 


Kinanan—On Irish Arenaceous Rocks. 563 


M.R.I.A., the beautifully sculptured cross on Devenish is cut in 
stone from the latter locality. 


[The quarries north and north-east of Kish are in the Calp sandstone; while those 
south-west of Kish are in a small outlier of Fermanagh sandstone. | 


Good hard silicious stones may be procured in the Derrygonnell 
Calp area, to the west of Lower Lough Erne—as in the neigh- 
bourhood of Church Hill. About Monea they are in general 

massive, with subordinate flaggy beds. Kerbstones were procured 
here for the village of Lisbellaw ; and in 1800 the town of Ennis- 
killen was paved with setts procured from this neighbourhood 
(G. 8. I). 

Some excellent stones have been noted in the CoaL-mEAsuRES 
to the west of the county. ‘They, however, are far away from any 
market or town, and are more or less difficult to get at: on which 
account, and also as good sandstone can be had more conveniently, 
they are not sought after. 

For the following list of quarries, with their distance from 
Enniskillen, we are indebted to Mr. John Wray, the Borough 
Engineer :— 


Carnmore, 23 miles; parish of Clones; Clones Church and 
Market-house. 

Mount, 15 miles; parish of Galloon; Railway Bridges from 
Clones to Enniskillen. 

Eskbradley, 15 miles; parish of Galloon ; Newtownbutler 
Market-house, Irvinmore Hall. 

Aughnabrock, 13 miles; parish of Aughavad; Ulster Bank, 
Enniskillen. 

Stonepark, 14 miles; parish of Kinawley ; Derryglin churches. 

Leighan, 7 miles; parish of Devenish; Bridges, Lillias river ; 
Kerbs, &c., Enniskillen. 

Rossanuremore, 15 miles; parish of Devenish; Bridge and 
Church, Garrison, Ballyshannon. 

Gilenashaver, 15 miles; parish of Innismacsaint ; Bridge be- 
tween Derrygonnelly and Garrison. 

Killroskagh, 14 miles; parish of Cleenish ; Belcoo and Holy- 
well Bridges. 

Aghnaglack, 12 miles; parish of Boho; Derrygore House, 
Enniskillen. 


SCIEN. PROC. R.D.S.—VOL. Y. PT. VII. 2Q 


064 Scientific Proceedings, Royal Dublin Society. | 


The round tower on Devenish, in Lower Lough Erne, is built 
of local sandstone, and displays good work, with ornamental 
mouldings at the base of the cone. There is also the very hand- 
some cross that was exhumed when the tower was repaired about 
1878. It displays elaborate and careful work. Since it has been 
placed in its original site it has considerably suffered from the 
weather. The stone, as already mentioned, seems to have been 
procured from the Kesh sandstone to the north-east of the lake. 

Sanp AND GraveL.—There is good pit sand near Irvinestown. 
Good river sand can be procured in many of the rivers and 
streams. That used at Lisnaskea is brought about two. or three 
miles, and what is used in Enniskillen is principally brought by 
boat from the River Arney, and from near Pettigoe. There is 
also good river sand near Irvinestown. 


GALWAY. 


The rocks north of Galway Bay are more or less granitic, and 
Professor Hull has stated that he considers that they are of Lau- 
rentian age, this opinion being grounded solely on their lithological 
characters. Unfortunately for this theory, although the rocks in 
the vicinity of Galway are more altered than elsewhere in the 
county, they graduate northward and westward into rocks only 
slightly altered, the fossils in which prove their true ages. The 
slightly altered rocks to the northward are not included in Pro- 
fessor Hull’s Laurentians, as in them are found fossils of Ordo- 
vician type; those, however, are to the westward. In the latter as 
yet no fossils have been found, but they have not been properly 
searched. The fossil evidence in the rocks to the northward proves 
that these so-called Laurentian rocks are some of the youngest of 
the metamorphic rocks of the Co. Galway. 


[It is evident that the time of the metamorphism which gives their present 
gneissose characters to the rocks was post-Ordovician; also that the granitic and 
schistose characters of the rocks are solely due to this metamorphic action, and not to 
the age of the rocks. | 


In West Galway the Ordovicians appear to have graduated 
downwards through the Areniy into the Cambrian, so that all 
are now more or less represented. In the more altered portions 


Kinauan—On Irish Arenaceous Rocks. 565 


(Ordovician) there are quartzytes and quartz rock (gneissen), while 
in the less altered portions to the north and to the westward (the 
latter classed as Laurentians) there are grits. 

To the east of the county, in the mountain groups (Slieve 
Aughta), there are also Ordovician rocks; they are not, however, 
metamorphosed. To the north of the county, from the Atlantic 
eastward to Loughs Mask and Corrib, is a long tract of Silurian, 
while margining the Slieve Aughta Ordovicians, and in two places 
on the shores of Lough Corrib—at Oughterard and Cong—are 
Carboniferous sandstones. In the Calp, north-east of Athenry, are 
calcareo-argillaceous sandstones. 

CampriANn (?), ARENIG, AND Orpovician.—In general the 
quartzyte and quartz rock are splintery, or break irregularly; in 
no case are they fit for dressed work. As much better stone can 
easily be procured, they are rarely used, except for local rough 
work. Some of the grits in the less altered Ordovicians are fair 
stones. 

Situr1aAn.—Good stones from fine to coarse conglomerates. 
Yellowish-greens, browns, and reds; some easily worked, but not 
in use, as the localities are backward, and there is no demand. 
Have only been used in local works. When building Maam 
bridge, although there was excellent and suitable sandstone in the 
vicinity, Nimmo brought limestone by water from Cong, Co. 
Mayo, as he considered it cheaper. 

CaRBonIFEROUS.—Some of the stones are well suited for cut- 
stone purposes. Those at the mearing of the county, to the west 
of Mount Shannon, have been already mentioned (Co. Clare, p. 
539). To the east of the county are other good stones, locally 
used in Woodford and Portumna. 

A little south of Cappagh, and north of Featherstone Lodge, 
westward of Woodford, there are stones capable of being ground 
to a smooth surface, and of making flagging similar to the “ Kin- 
nity flags,” King’s County (p. 576). 

Benmore. ‘Two miles from Woodford.—A fine freestone ; can 
be raised in large blocks ; suitable for all cut-stone purposes. 

Sleve Dart. North of Dunmore, to the north of the county, 
and partly in the Co. Mayo.—The massive pebbly grits were 
formerly extensively wrought into millstones. In this hill, not 
very long ago, was raised very extensively a very thin laminated 

2Q2 


566 Scientific Proceedings, Royal Dublin Society. 


smooth flag, locally known as Dunmore slate. This, in old times, 
was used for roofing instead of slate, as will be seen on the old 
houses in Dunmore, Tuam, and the neighbouring towns in the 
Co. Mayo. It made a good substantial roof, the weight of the 
“‘slates”’ being suitable to the heavy gales and storms of the 
county. They were not very unsightly; far less so than the 
“Stourbridge slate,’ used in Oxford, England. They, however, 
required heavy timbering to support them. 

In the vicinity of Cong and Oughterard, the tracts of Lower 
Carboniferous Sandstone are of limited extent, and the sandstone 
is but little used on account of the excellent limestone in such ex- 
tensive tracts in those localities. 

As loose stone in the islands, and along the shores of Lough 
Corrib, are some peculiar sandstones. They have not been ob- 
served in situ, and possibly may be of Silurian age; but in 
appearance they are more like the Carboniferous rocks. In 
weathering, excrescences like small gooseberries grow out 
from some, while others become pockmarked, small concave hol- 
lows weathering into them. The latter stones, when weathered, 
are extremely durable, as can be seen in the chancel arch of the 
ancient church on Inchnagoill, in Lough Corrib. This arch was 
restored some years ago by the late Sir B. L. Guinness, Bart., the 
missing stones being supplied by ashlers cut from similar stones 
picked up along the shore of the island. The old and new stones 
were so similar, that now, after a lapse of thirty years, it is hard 
to say which are the new ones. 

It is hard to explain the cause of the growing on the sur- 
face of the stone of the “ gooseberries.” We learn, however, 
from breaking a block that the “pockmarks” are due to small 
globular secretions of ferrifero-chloritic matter, that rapidly de- 
cay even when exposed to the air. After they are gone, the rest 
of the stone is very durable. 

Sanp AND GraveL. -These in this county are interesting as 
well as useful. In the low country, east of Galway Bay, and ex- 
tending northward into the adjoining counties, are the Eskers that 
are found more or less continuously across the central plain of Ire- 
land ; and where they occur there is a plentiful supply of good 
sand for building purposes, and also gravel for road metal. Out- 
side the limits of the plain, good pit sand ‘can be obtained at 


Kinanan—On Irish Arenaceous Rocks. 567 


Knocknacarra, near Barna, three miles west of Galway, and in 
various places in the hills of Connemara, but more especially in 
the ridges between Kylemore Lake and the sea. In the West 
Galway hills there are also in places large accumulations of fine 
sand, locally called “ Rabbit Sand,” considerable dunes of it oc- 
curring in the valley northward of Lough Inagh. 

Tn connexion with many of the lakes there are considerable 
accumulations of good sand, that at the east end of Kylemore 
Lough being remarkable for its size, as apparently it is quite 
recent. At Lough Cooter, in the south of the county, is silicious 
sand which, as in the neighbouring county of Clare, already men- 
tioned, is famous for its use in the manufacture of scythe-boards. 

In the rivers and streams there are excellent sands, those of 
the Gort river and neighbouring hills (Slieve Aughta) being su- 
perior. In the north of the county there is also sand worthy of 
note in the Hrriff river that flows into the Killary, it being of 
good quality and silicious, being made up of the detritus of the 
Silurian sandstones from the adjoining highlands. Some of these 
sands appear to be suitable for glass purposes, although none of 
them ever seem to have been so utilized. 

The sea sands are of importance. Some are very suitable for 
building purposes; while in many places along the seaboard are 
tracts or dunes of blown sand (Holian drift) of greater or less 
extent. All of these are valuable as manure for the boggy land, 
some eminently so, being very calcareous, containing from fifty to 
seventy-five per cent. of limy matter. In the north Sound, Gal- 
way Bay, there are banks of sea sand made up of broken pieces of 
nullipores. Formerly these were extensively utilized; but they 
have not been as much sought after since the introduction of arti- 
ficial manure. 

[If the bog-land is impregnated with iron, the bog must he first drained before 
sand is applied, as otherwise the sand does more harm than good. It changes the iron 


into a soluble carbonate, in which state it is sucked up into the pores of the plants, 
where it becomes oxidyzed, and kills or deteriorates them. | 


KERRY. 
The geological groups in which sandstones and grits occur are 
the Ordovician, Liandovery, Silurian, Devonian, and Drift. 
In the Dingle promontory is a narrow tract of Ordovicians, 


068 Scientific Proceedings, Royal Dublin Society. 


called by Jukes and Du Noyer the Anascaul beds. Adjoining these 
are Silurian, the upper group of which has been called the Dingle beds, 
and the lower group the Smerwick beds, the typical Silurians occur- 
ring between, as other groups. The Smerwick beds are probably in 
part the equivalents of the Llandovery or May Hill sandstone. 
These passage beds between the Ordovicians and Silurians are very 
similar in aspect and composition to the Devonians, or passage 
beds (Dingle beds and Glengariff grits) between the Silurian and 
Carboniferous, they both belonging to the red types, formerly. all 
included in the “‘ Lower Old Red Sandstone.” 

[The term Old Red Sandstone once included all red or reddish sandy rocks below the 
Carboniferous limestone; but by degrees, group after group, as geological knowledge 
increased, were given special names, and separated from it, till eventually the rocks 
that remained were those that lay between the Carboniferous limestone and the typical 
Silurian. Now, however, it is learned that of this remainder the upper portion 
belongs to the Carboniferous and the lower to the Silurian, while the intermediate 
passage beds are all that remain to be called either Lower Old Red Sandstone or Devo- 
nians. ‘These beds above the Silurians, also those below them (Mayhill sandstone or 
Llandovery), are very similar in aspect and composition ; so that in places one has been 
mistaken for the other. This wiil be referred to hereafter when describing the rocks 

the counties Mayo, Roscommon, and Sligo. | 


To the south-west of the county are the reddish to greenish 
type of Silurians that have been called Gilengariff grits. They in 
part represent the upper portion of the Dingle beds, and in part 
higher strata. ‘These Glengariff grits graduate upwards into the 
Devonians, and the latter into the Carboniferous. The Carbo- 
niferous rocks in this part of Kerry, that is in the neighbourhood of 
the bay called Kenmare river, are for the most part of the “‘ West 
Cork type,” they, except near Kenmare, being Carboniferous 
slate and Coomhoola grits ; but at Kenmare there is a small tract of 
_ limestone, and lower limestone shale intervening peculiarly. 

In the Dingle promontory margining the Silurians, and lying 
unconformably on them, are Devonians. These evidently are the 
equivalents of the Devonians to the north and south of Kenmare 
river, and in the adjoining portion of Cork; but in the south part 
of Kerry and in Cork the upper portion of the Glengariff grits is 
present, while in the Dingle promontory it is absent, thus necessi- 
tating the Devonian of the Dingle promontory to lie uncomform- 
ably on the Silurian (Dingle beds). In the neighbourhood of 
Kerry Head there is an isolated tract of Devonians. The Devo- 


Kinanan—On Trish Arenaceous Rocks. 569 


nians of the Kerry Head district and Slieve Mish graduate 
upwards, through the Lower Carboniferous Sandstone (Yellow 
Sandstone) and Lower Limestone Shale into limestone, while to 
the east of the county, on the latter, are the Coal-measures. 


[The types here are quite different to those in the Kenmare River Valley, except 
as mentioned, in the vicinity of Kenmare, where the rocks are allied to those of the 
north-east. ] 


The sandstones, especially those in the Devonians and Coal- 
measures, were much more used in old times than at present, as 
now limestone is generally preferred for cut-stone purposes. The 
sandstones of the county were, however, principally used in the 
early Norman architecture; and, from these ancient structures, 
as exhibited at Ardfert, and in different other ancient ecclesias- 
tical buildings, they seem capable of making good and durable 
work. 

Oxpovictan.—The grits and sandstones of this age are not of 
much account at the present time, except for local purposes, as 
the localities in which they occur are more or less inaccessible. 
Some of the early structures in the area would suggest that they 
were capable of being used in good and durable work. 

Luanpovery or Passage Bens (Smerwich series) and SILURIAN. 
—In the Smerwick series there are many excellent stones of 
reddish, purplish, and brownish colour, none of which are in 
demand on account of their isolated and inaccessible position. In 
the groups next above (Ferriter Cove and Croaghmarhin series) there 
are some good beds; but in general they do not appear to be 
eminently suited for cut-stone purposes ; but in the highest group, 
Dingle beds, there are some first-class stones, suitable not only for 
cut-stone purposes, but for all sorts of heavy work, being capable of 
being raised in blocks of large dimensions. ‘There is, however, 
only a small market for them, and they seem to be used nearly 
solely for local purposes. In the county south of Dingle Bay, in 
Glen, or the valley adjoining St. Finan’s Bay, there is the old 
structure called after that saint. It is a cloghaun, or bee-hive 
house, built of a fine-grained sandstone of the locality (Glengaryff 
grits), without mortar. The stones in the interior of the cell were 
so neatly joined and put together, that when visited some twenty- 
five years ago they presented a perfectly smooth and even sur- 


570 Scientific Proceedings, Royal Dublin Society. 


face, while the joints were so perfect that it was nearly impossible 
to insert the blade of a knife between them. 

Minnard. Seven miles from Dingle.—Red ; very fine; a good 
colour; very durable; can be raised in large blocks; was used for 
ashlars and face-work in the Roman Catholic church, Dingle. 

Mr. Deane also mentions “a green stone in the Dingle dis- 
trict, used for building purposes.” 

Ventry. — Yellowish-brown ; compact; not heavy; easily 
worked. 

Killarney.—Dark-grey ; very silicious; slightly granular. 

Ballycarberry (Iveragh).—Purplish-grey; very silicious; slightly 
micaceous. 

DEVONIAN AND CarBonirERous.—These vary from coarse conglo- 
merates to a fine-grained sandstone or grit. They are often flaggy, 
and for the most part are reddish, purplish, or yellowish in colour. 
In general they are durable, and many of them can be raised in 
blocks of greater or less dimensions, being eminently suitable for 
rough work, such as piers, bridges, and foundations. They are 
also capable of producing good, sound, fine work, as exemplified in 
the ancient structures. Rattoo Round Tower, in the Kerry Head 
district, appears to have been built from a hard quartzose sand- 
stone, procured in the vicinity; and it displays a cut-stone band 
round the doorway in good preservation. 

In Derryquin Castle, which is principally built of the slate 
rock of the locality, some of the quoins are, to quote Wilkinson, 
“of a grey-coloured sandstone resembling pumice-stone, which is 
soft, and works in any direction, but hardens and becomes very 
durable on exposure. Itis found in a long, narrow vein, adjoining 
the red sandstone, and occurs near the coast, continuing inland 
towards the Staigue fort.” 

Poulawaddra Wood. Three miles from Tralee.—Red; soft ; 
fair-working; Lord Kenmare’s castle, Killarney; new Railway 
Station, and various houses in Tralee. 

Tonenane. Three miles from Tralee.—Similar stone to that at 
Poulawaddra; used in both of the Roman Catholic Churches, 
Tralee, and other smaller structures. 

There are other smaller quarries in Slieve Mish besides those 
mentioned. Mr. W. H. Deane, County Surveyor, considers the 


Kinauan—On Irish Arenaceous Rocks. 571 


sandstones to be easier worked than the limestones, but not as 
durable. 

From near Glenbehy were procured the stones for the ashlar 
work in Aghadoe, Lord Headly’s mansion, near Killarney, built 
some fifty years ago. 

- CoaL-MEASURES.—As already mentioned, there are excellent 
stones in places in this area, but now in general superseded by the 
limestone. At Barleymount is a quarry, from which the stone was 
taken for walling-in Aghadoe mansion. 

Armagh. North of Milltown.—A quarry in a good brown 
stone. 

In different places in the “ Flagstone series,”’ near the base of 
the Coal-measures, flags have been raised. They are not, how- 
ever, as well developed as in the Oo. Clare, to the north of the 
Shannon ; while there is nearly invariably a considerable “‘head”’ of 
drift, that makes them expensive to quarry ; consequently, they 
are rarely looked after, it being cheaper to use the “Clare flags.” 
At Ballylongford there are fair flags, with black shale partings, at 
one time quarried for the general markets; while elsewhere are 
small quarries, that were opened for local purposes. 

SAND AND GraveL.—Pit sand and gravel occur near Kenmare, 
near Tralee, and in the neighbourhood of Killarney; while good 
river sand is procurable in most of the rivers and streams, especially 
those having their source in Slieve Mish, which carry down a red, 
sharp, clear sand, used extensively in Tralee. 

In several places on the coast of Tralee Bay is a sea sand, 
which is used in Tralee with the stone saws for cutting blocks. 

Holian sand dunes occur in places along the coast. Tormerly 
the calcareous varieties of these sands, as also the shell sands 
dredged up in the bays and the estuary of the Shannon, were 
highly valued as manure, especially for boggy land. ‘These used 
to be carried for great distances inland on horseback, even across 
the hills into the Co. Limerick. 

Guass.—There seems to be no records of glass being manufac- 
tured in this county, although some of the fine sands from the 
Devonian hills seem well suited for the purpose. 


O72 Scientific Proceedings, Royal Dublin Society. 


KILDARE. 


In this county there are not any sandstones that are now used 
for cut-stone purposes, while the places in which sandstones occur 
are of very limited extent. 

Stones required for dressed or cut purposes are obtained from 
the limestone quarries at some distances, or from the granite 
range in Wicklow or Carlow. 

In the Orpovicians to the east margin of the county, and in 
the small protrudes at the Chair of Kildare and Red Hill, there 
are some subordinate grits and sandstones; while there are Car- 
BONIFEROUS conglomerates and sandstones margining them in 
places, and coming in from the Co. Dublin, at the Hill of Lyons, 
to the southward of Celbridge. At Newtown, some miles west 
of Maynooth, in an outlying patch of CoaL-mEasurss, there are 
also some subordinate beds of grit. 

CarBoniFrerous.—Red Hill, a quarry at the northern end.—Red 
conglomerate ; formerly quarried for millstones. 

Hill of Alien.—Grits ; formerly extensively quarried for mill- 
stones. 

Baillindolan. North of Edenderry.—Blackish flags ; argillaceous. 
and slightly calcareous; used in Kdenderry, King’s County. 

SAND AND GraveL.—These are common everywhere in the low 
country ; but some of the sands require to be washed before being 
used for building. In places there is a sand with a latent calca- 
reous cement: this, when opened in the pits, stands with a perpen- 
dicular wall, which does not weather or slip. This sand is valuable 
as a manure, and formerly was extensively used. 


KILKENNY. 


To the south-west, coming in from the Co. Tipperary, and to 
the south-east, coming in from the Counties Wexford and Water- 
ford, are limited tracts of Ordovicians (?), in the latter partly altered 
and associated with granite intrusions; while margining these 
areas are Carboniferous Sandstones. To the north of the county are 
Coal-measures, part of Slieve-Margy, but now more generally 
known as the Castlecomer Coal-field. 


KinaHan—On Irish Arenaceous Rocks. oe 


In this county, as so common elsewhere in Ireland, sandstone 
formerly was extensively used, but afterwards was superseded by 
limestone. As pointed out by Wilkinson, the ancient structures 
testify to the beautiful finished and durable work the stones were 
capable of producing, as specially exhibited in the exquisite door- 
way of the church in Killeshin Glen, a little south of the road 
from Carlow to Castlecomer. According to Wilkinson, the local 
sandstone was used, and this doorway, as also the doorway of the 
Round Tower, Timahoe, Queen’s County, were “evidently con- 
structed by the same workmen.” 

The same authority states that the columns, mouldings, and 
other dressings in Jerpoint Abbey also show what the Carboniferous. 
Sandstones are capable of being put to. Its dressings are of the 
Lower Carboniferous Sandstone from the neighbourhood, and still 
show the chisel marks after seven hundred years. It is generally 
believed that the stone was got within a mile of the Abbey, where 
there are any amount of blocks on the surface. 

On the authority of Wyley, it is stated that the sandstone 
in Jerpoint Abbey was procured in the southern portion of the 
townland of Ballyhowra. ‘‘The stone is very soft, composed of 
grains of quartz and earthy felspar, with mica to a small amount.” 
‘The tradition is that, when the particular beds of stone were. 
reached, they were wrought underground in the form of a tunnel.” 
He considers the stone unfit for outside work. Wyley, in referr- 
ing to the ruins of an old church half-way between Knocktopher 
and Newmarket, states that the stone is similar to that used in 
Jerpoint, but that it may have been procured either in the Knock- 
topher or Newmarket quarries. (G. S. IZ.) 

As mentioned by Mr. Langrish, “ Brownstone House,”’ on éhe 
left bank of the Nore, between Thomastown and Inistioge, is built 
of a highly silicious stone of the district, greenish to purplish in 
colour, hard to cut, but looks very well. Some of the dressings of 
Inistioge Abbey, founded 1262, are of this stone and of the hard 
purple conglomerate which shows in Coolnahan Mountain, between 
Inistioge and Waterford. It is remarkable how shallow the 
mouldings were in comparison with those cut in the limestone. 
At Coalcullen, in the Coal-measures, about four miles from Castle- 
comer, is a stone of a light-brown tint, and easily worked; it 
was largely used in the restoration of St. Canice’s Cathedral, 


O74 Scientific Proceedings, Royal Dublin Society. 


Kilkenny. A similar stone occurs near Rosenallis, at the foot of 
Slieve-Bloom. Both are excellent for inside work. The fine-cut 
stone house of Castletown, near Carrick-on-Suir, built by Arch- 
bishop Cox more than one hundred years ago, has the south front 
of a darkish sandstone, apparently got in the neighbourhood. 
The Coolnahan conglomerate, above mentioned, rises in large 
squared blocks, eminently suitable for the coping of quay walls 
and such like works, as do also the rocks in the glen at Catsrock, 
near Tory Hill. 

Aghavaller Round Tower is built of a brown, slaty-textured 
grit stone, in irregular courses. 

Orpovician.—The grits and sandstones in this group are 
almost invariably hard and splintery, not being adapted for cut- 
stone purposes. ‘hey are, however, used for rough local work. 

CaRBONIFEROUS.— Very excellent stones occur in various places 
both in the Lower Carboniferous Sandstone and in the Coal-measures, 
as just now mentioned. The hill of Drumdowney was formerly 
famous for its millstones, which were said to be equal to the 
French. ‘They were sent by water to England, Dublin, Cork, 
Waterford, and elsewhere. Some of the largest were 5 feet in 
diameter, and 16 inches in the eye. ‘They were shipped with ease 
on the Barrow, at the base of the hill. ‘The last stones, wrought 
about 1876, are in Saul’s Mills, near the locality. On the same 
hill there was also a vein of white stone, fit for all cut-stone pur- 
poses of small dimensions. . 

Lower Carponirerous Sanpstone.—Baunbree. Near Scagh 
eross-roads, four miles from Carrick-on-Suir.—Brown, reddish, and 
yellowish ; kind; apparently durable ; used in the Roman Catholic 
church at Tallaghast. 

Annefield, or Tullynacranny, and Oldcourt. Five miles from 
Carrick-on-Suir.— Yellowish. The stones, except the quoins, which 
are limestone, for Pilltown New Church were got from Bregaun 
Hill, near the Annafield plantation. 

Drumdoney. Four miles from Waterford.—Red sandstone. 

Mr. P. Burtchael, County Surveyor, points out that, although 
there are now no quarries open, good stone ought to be procurable 
from the Lower Carboniferous Sandstones in the neighbourhood of 
Thomastown, Jerpoint, Kiltorcan, and Callan, as attested by the 
ancient ecclesiastical and other structures. At Coolhill, near Kil- 


Kinauan—On Irish Arenaceous Rocks. OVO: 


lamery, there are conglomerates suitable for rough work ; while at 
Kalmaganny there is a nice, durable yellow stone, used for cut- 
stone purposes in the entrance gate, Rossenarra, and in houses in 
the village. 

In the Lower Coat-mzasures at Shankill, Kellymount, and 
Conahy, are procured the flags known as CarLtow F acs, on 
account of their being carted to that town, and sent from thence 
by water to the different markets. The Shankill flags were 
considered the best, and ranged in thickness from 4 inches to 
half an inch. They could be raised as large as 12 or 14 feet 
square, but in general from 8 to 10 feet long, and 3 to 4 feet wide. 
At Kellymount the flags were very similar, but of a lighter colour. 
At Conahy they were considered inferior. Some of them were so 
thin, that formerly they were used for roofing. Formerly there 
was a very extensive trade in these flags; but as the “ clearing” 
or “baring” increased on the flag strata, so did the expense of 
getting them, and they were undersold by other flags. Since then 
the introduction of asphalt and other artificial footways has greatly 
lessened the demand for all flags here and elsewhere. 

In Conahy, as pointed out by Mr. Burtchael, some of the 
stones have natural dressed surfaces (‘“‘ edgers’’), which show well 
as quoins or facings, having the appearance of “‘ nice square cut- 
stone blocks.” 

Kiltown. Half a mile from Castlecomer.—Yellow and grey ; 
durable; easily worked ; used in the Roman Catholic Church and 
the wing of the Wandesforde mansion, Castlecomer. 

Coolcullen. Five miles from Castlecomer, and nine from 
Carlow.— Yellowish, kind, and works easily. Used in interior 
work during the restoration of St. Canice’s Cathedral, Kilkenny, 
and recent work at Freshford Church. Mr. Burtchael points out 
that the carvings of the ancient doorway of Freshford Church 
are greatly worn and disintegrated, the stone apparently being 
like the Coolcullen stone. 

Red Sandstone from the vicinity was used in Thomastown 
Abbey for the capitals of the pillars between the nave and side 
aisle. On them the carved foliage is much weathered, having 
been for centuries exposed to the elements, although originally 
under cover. (J. G. Robertson.) Mr. Robertson points out that, 
in St. Canice’s Cathedral, Graigue-na-Managh Abbey, Jerpoint 


576 Scientific Proceedings, Royal Dublin Society. 


Abbey (?), and Grenan Castle, in this county, the stone is the 
same as that so largely used in Christ Church, Dublin, and 
in the Co. Wexford, in St. Mary’s New Ross, and in Bannow 
Church. 

Sanp AND GRAvEL.—Good pit and river sand is very general 
throughout the county. 

According to Mr. Langrish, the best sand in Kilkenny is in 
the valley of the Nore, at the town. There are good banks else- 
where along the river, but near Thomastown it is mixed with clay. 
The fine sand for the Kilkenny Marble Works is procured out of 
the Nore at Three Castles, four Irish miles from the town. 

Mr. Burtchael points out that excellent pit sand was got at the 
site of the new glebe-house, Piltown, while the adjoining town- 
land is called “ Sandpits.”” Good sand is also to be obtained near 
Goresbridge, Inisnag, Thomastown, Castlecomer demesne, and 
Massford; Kiltormer, near Callan; also Ballincreas, about five 
miles from Waterford, Ballylusky, one mile, Ballida, two miles, 
and Knockhouse, three miles from Mullinavat or Kilmacow Railway 
Station; Ballyhahy, between four and five miles from New Ross ; 
and, in fact, very generally over the county. 

In a cave at Serville Lodge, one mile from Kilkenny, on the 
Callan road, is a very fine sand, but quantity very small. 

A sand with a calcareous cement was formerly most extensively 
used as manure; some of the pits are so extensive, that it 
has been calculated that they have been worked for at least one 
thousand years. A sand, considered specially good on hilly ground, 
was known as Kilmacow sand, probably from having first been found 
or used in that neighbourhood. 

Along the tidal portions of the Nore and Suir there is a large 
tract of what is called manure sand, which used to be loaded into 
barges at low water out of the banks. It contains a large per- 
centage of very fine sand, and was good for heavy soils. 


KING’S COUNTY. 


The principal localities for arenaceous rocks are the Ordovicians 
and overlying Carboniferous Sandstones (Upper Old Red) in the 
portion of Sleve-Bloom that comes into the south-east of this 
county. ‘To the south of the county, in the vicinity of Moneygall, 


Kinanan—On Irish Arenaceous Rocks. OV”d 


coming in from the Oo. Tipperary, are small tracts of similar 
rocks; while at the western margin there are sandstones on the 
eastern flank of Knocksheegowna, that may extend into this 
county. 

At the present time none of these stones are in demand for 
cut-stone purposes, although some of them are eminently suitable, 
and were used in the ancient structures. In the ecclesiastical 
settlement at Clonmacnoise, although in the limestone district, and 
close to an excellent stone of that class, sandstones of a thin, flat- 
bedded character were used in some of the churches, while the old 
crosses were wrought out of a fine-grained quartzose sandstone. 
This is interesting, because, although in places such as Cloyne 
(Co. Cork), Cashel (Co. Tipperary), and elsewhere, the first structures 
were built of the local sandstone, in the subsequent ones limestone 
brought from a distance was used. 

CaRBONIFEROUS.—Kinnity.—In various places more or less 
near this town, along the north-west flanks of Slieve-Bloom, are 
small quarries. In some quarries the stones are from 1 to 4 feet 
thick, and are capable of being easily worked. In other quarries 
there are flags of a warm yellowish colour, that are excellent for 
inside work, as they are capable of being finished so finely as to 
give an even surface, in which the joints are scarcely perceptible. 
At Gurteen, about nine miles from Roscrea, flags are raised for 
use in that town; they vary from 1°5 to 3 inches in thickness. 

The monument to the Duke of Cumberland in the public 
square of Birr, or Parsonstown, is of sandstone from the Slieve 
Bloom district, but whether from bad construction or bad selection 
of the stone, it does not now give a good appearance. 

Sanp AND GRAVEL.—The Eskers are numerous in this comahy, 
and they supply an unlimited quantity of good sand; also excellent 
gravel for road metal. ‘The limestone gravel is much used for 
manure, the best being found in hillocks or at the foot of the hills. 
This gravel, when burnt in heaps with the paring of the bogs, 
gives a very rich manure for tillage. 

Guass was formerlyJextensively manufactured in Birr, or Par- 
sonstown; but when Lewis wrote, in 1837, only the ruins of the 
glass-house remained. 

In 1652 Boate wrote: ‘“ Several glass-houses set up in Ireland ; 
none in Dublin or other cities, but all of them in the country ; 


578 Scientific Proceedings, Royal Dublin Society. 


amongst which the principal was that of Birre, a market town, 
otherwise called Parsons-town, after one Sir Laurence Parsons. 
.. » From this place Dublin was furnished with all sorts of 
window and drinking glasses, and such others as commonly are in 
use. One part of the materials, viz. the sand, they had out of 
England ; the other, to wit, the ashes, they made in the place, of 
Ashtree, and used no other. The chiefest difficulty was to get the 
clay for the pots to melt the materials in ; this they had out of the 
North.” 


LEITRIM, 


At the south-east of the county, margining Longford and 
Cavan, also in a small exposure near Drumod, are Ordovicians, on 
which reposes the Lower Carboniferous Sandstone. A. small exposure: 
of Silurians, associated with Lower Carboniferous Sandstone, occurs. 
near Drumshambo, to the south of Lough Allen: adjoining that 
lake there is a considerable tract of Coal-measures, a portion of 
the ConnauGut CoaL-FIELD; while farther northward there is 
a small outlying patch of similar rocks to the south-west of Lough 
Melvin. ‘T'o the west, coming in from the Co. Sligo, is a ridge of 
metamorphic rocks running north-east to and past Manorhamilton. 
These rocks have been said to be Laurentian, but this is highly 
improbable (page 517) ; and for the reasons given when describing” 
the Donegal rocks (page 548), it is probable that they are the 
equivalents of the Arenig or Cambrian. 

ARENIG (?) oR CaMBRIAN (?).—These rocks consist of green 
quartzyte and other schists. None of the quartzyte is suited for 
cut-stone purposes, but it may be used for flags, in rough work, or 
for road metal. 

OrpoviciAn.—Some of the grits and sandstones belonging to 
' this group seem not to be suited for cut-stone purposes, but locally 
they are used for rough work. 

Siturran.—There is only a very small area occupied by these 
rocks. Good stone can be procured in quantity in some places, 
but they are not sought after; they are, however, used for local 
purposes. 

CaRrBONIFEROUS.—In places, but especially in the south of the 
county, the strata adjoining the older rocks are reddish or purplish 
in colour, and range from conglomerates to fine sandstone. Some 


Kinanan—On Irish Arenaceous Rocks. 579 
beds, however, here and elsewhere are lighter in colour, being grey 
and yellow. 

Greenan. Four miles from Mohill, loose masses of sand- 
stone. Between four and five miles from Mohill there are several 
quarries in whitish and brownish-yellow stone, from which large 
blocks can be obtained. 

Between Dromod and Drumsna, eastward of the road, are 
different quarries. Whitish, clean, even-grained, quartzose, thick- 
bedded; irregularly jointed but very large squared stones can 
be obtained; it dresses well, but is hard to work. This is not 
much used; but the ashlars, groins, and sills for the Aughamore 
Roman Catholic church were obtained here, and have produced 
sharp and durable work. 

Cloonmorris. Between Dromod and Newtownforbes.—School- 
house, rubble and walling ; free-working and durable. 

Crummy. North-east of Carrick-on-Shannon.—School-house, 
rubble and walling; very free-working and durable; dressing 
from Creeve (limestone), Co. Meath. 

Curnagan, Parish of Fenagh.—A quarry once well known for 
its millstones. 

Willea. Seven miles from Manorhamilton.—Stones vary in 
colour and composition. The best is whitish. Fine-grained, sili- 
cious, works freely ; large blocks can be obtained. Other beds 
are greyish, slightly argillaceous or micaceous. The quarry was 
largely worked, but expensive, on account of a heavy bearing, and 
the upper stones being deteriorated by stains. 

Glenfarn. Nine miles from Manorhamilton.—Greyish-white, 
coarse-grained, silicious, argillo-silicious cement, works well. 

In various localities in the Coal-measure hills there are said to 
be good stones; but they are difficult of access. In places are 
seams of thin-bedded sandstone suitable for flagging, the natural 
surface being quite even, and, as they are hard. they are very 
durable. The flags from the Arigna Hills have been used in 
Carrick and Mohill, and those from Glenfarn in Manorhamilton. 

Sanp AND GravyeL.—In the country to the eastward of the 
Shannon the pit sand in general is good; but westward of that 
river, for the most part, it is inferior. 

Good river sand occurs in different places all over the area, but 


often in limited quantities. 
SCIEN. PROC. R.D.S.—VOL. V., PT. VII. 2R 


580 Scientific Proceedings, Royal Dublin Society. 


LIMERICK. 


To the east of the county, coming in from Tipperary, are 
Ordovicians, overlaid by Lower Carboniferous Sandstone. Also to 
the south of the county, in Slieve-na-Muck and the Galtees, there 
are Ordovician exposures, with Lower Carboniferous Sandstone mar- 
gining. In the plain of Limerick are a few outlying exposures 
of the latter rocks; while in places in the limestone, as adjuncts 
of the subordinate inlying traps, are tuffose sandstones. 

To the west of the county are Coal-measures, a part of the 
Munsrer Coau-FIELD, while small outliers of similar rocks are 
found at Ballybrood and Slieve-na-Muck. 

Orpovictan.—The grits in this group, as elsewhere, are of 
little value for cut-stone purposes, although useful locally. 

Carponirrrous.— These range from a conglomerate to fine 
sandstone and grit. Although not now much in demand, in places 
there are superior stones in the Lower Carboniferous Sandstone. 

Doon.—In this neighbourhood there is specially fine freestone, 
which at one time was largely shipped to Hngland and other 
places. The stone is tough, equal to heavy bearings, and can be 
raised in long scantlings—on which account very suitable for stair- 
cases. It was used for the staircases in Clarina and Adare manors. 

Glenstal Castle was built of a good whitish stone procured in 
the neighbourhood of Morroe. 

St. Oswald’s, near Ballingarry, was built with stone procured 
from [nockfierna. Some of the stones in the quarry were easily 
worked, while other beds were as hard as flint. The house has 
been built over thirty years, and Captain Wilkinson states the 
-stones seem to have hardened. Stone from near this quarry was 
used in the Ballingarry Court-house and Church, but not for cut- 
stone purposes. Mr. Horan, County Surveyor, is of opinion that 
good stone might be got in this hill if a quarry was opened sut- 
ficiently. At present the stone is principally used for rubble work. 
Near Ailmeady there are quarries in silicious grits. In the Slieve- 
na-Muck range, near Galbally, fair stones might be procured. 

At places in the limestone associated with the intruded and 
bedded igneous rocks are tuffs, that range from massive agglo- 
merates through conglomerates into fine sandstones, often calca- 


Kananan—On Irish Arenaceous Rocks. 581 


reous. They are purplish, reddish, and greenish in colour. Where 
fine-grained they cut easily and well, but are not durable. A 
green variety, raised out of an adjoining quarry, was extensively 
used in the building for the new railway station at Limerick. 

An agglomerate, that rises in massive, squarish long blocks, 
was used in the ancient megalithic structures in the neighbourhood 
of Lough Gur. 

In general the CoaL-MEASURE grits are very quartzose, and hard 
to cut or dress, and are not favourably thought of. They have, 
however, been used in many of the bridges. In places there are 
excellent flags, similar to those imported from Money Point, Co. 
Clare. ‘These have, to some extent, been worked in the neigh- 
bourhood of Athea, and also at Barna; and the latter were used 
in Newcastle and Rathkeale. When first raised, they are soft 
and easily tooled, but afterwards they become very hard. They 
also occur in the hills near Glin. 

Sanp AND GRAVEL.—Pit sand occurs in the neighbourhood of 
Limerick, near Kilmallock, near Rathkeale, and in other places. 
Good river sand can be procured from the Shannon above Lime- 
rick, in the Deel river, near Newcastle, and in greater or less 
quantities in the mountain streams. Shell sand for manure was 
formerly procured from the estuary of the Shannon. ‘There are 
also in places, at about the 240 feet contour line, accumulations of 
gravel suitable for road purposes. 


LONDONDERRY. 


The sandstones occur in the Ordovician, Llandovery (?), Silurian, 
Carboniferous, Triassic, and Jurassic groups. ‘To the south of the 
county, coming in from the Co. Tyrone, are older rocks, probably 
the equivalents of the Arenig or Cambrian, that are metamorphosed 
into gneiss and schists. 

Orpovicrans AND LiaNnpDoveRy (?).—These are more or less 
metamorphosed. Some of the less altered sandstones cut fairly 
well, but are not in request, as better stone can be procured in the 
Carboniferous. A peculiar, finely-laminated sandstone (book or leaf 
sandstone) ; is very good for walling purposes, and has been exten- 
sively used in the neighbourhood of Derry. 


Prehen (Derry).—Bluish ; of a slaty nature. Does not stand 
2R2 


582 Scientific Proceedings, Royal Dublin Society. 


well, except on the beds, as it is liable to peel and to break at the 
joints. Used in the Public Offices, Diocesan Seminary, Foyle 
College, Gwynn’s Institution, Roman Catholic Cathedral, &e. 

Sirurtan.—The rocks belonging to this formation are of the 
“ Lower Old Red”’ type, being reddish and purplish conglome- 
rates and sandstones. ‘They occur to the west and south-west of 
Draperstown. They are not a desirable stone. 

-CarsoniFerous.—There are some first-class stones in these 
rocks, as hereafter mentioned. They have not, however, been as 
much in demand as they ought to be, on account of the expense of 
land carriage, which has allowed them to be cut out of the market 
by stone imported from Scotiand. 

These stones range from coarse quartzose conglomerates into. 
fine silicious grits and sandstones of yellowish shades. The latter 
are easily worked when first quarried, and harden on exposure. 
They are good for both inside and outside work, and in the old 
buildings, in which they were very generally used, they exhibit 
their soundness and durability. 

Gort-a-hurk, near Maghera.—Oreamy-white, with subordinate 
greenish beds; very silicious, granular, but little cement; does. 
not work freely. The beautifully and elaborately sculptured door- 
way of Maghera ancient church, wrought out of this stone, proves 
its eminent durability. It has been used in Magherafelt. 

Fullagloon and Ranaghan. ‘Three to four miles north-west of 
Maghera.—F lags, tombstones, door-steps, sills, and scythe-stones. 
procured in different places; principally worked near the road to 
the south of Ranaghan. 

Carnamoney (Moyala river). Four miles south-westward of 
Maghera.—Grey and yellowish, silicious; easily worked; used for 
tombstones, sills, quoins, &e. 

Drunard. Near Draperstown.— Bluish. This stone, some 
years ago, was opened on by the Grahams of York-street, Belfast, 
and was considered by Mr. A. P. Sharpe, of Dublin, to be a first- 
class stone. At that time, however, on account of backward situa- 
tion, and the great expense of getting the stone from the quarry 
to the market, the enterprise had to be abandoned. 

At one time the stones from this part of the county were in 
considerable demand, and were carted to Ballyronan, on Lough 
Neagh, where they were shipped to Belfast and other places. 


Kinanan—On Irish Arenaceous Rocks. 583 


Drumquin.—Y ellowish, fine-grained, works freely; when raised, 
very wet, but dries on exposure; not very durable. ‘This stone 
was formerly much used in Coleraine and Limavady. 

Altmover. West of Dungiven.— Various quarries, varying 
from white and creamy to reddish greenish-grey; semi-crystal- 
line; argillo-silicious cement; some beds with sand holes. Thin- 
bedded stones used as flagging in Limavady. 

From these and other quarries are procured the stones known 
as the Dungiven stone; and in these different quarries special 
beds must be better than others, as there is a diversity of opi- 
nion as to its quality. From a quarry then known as “ Bally- 
hagan” were procured most of the stones for the Bishop of Derry’s 
(Lord Bristol’s) palace at Ballyscullion ; but the portico was built 
of Ballycastle (Co. Antrim) stone (page 532). To the north of 
Dungiven a quarry has been opened of late years, from which a 
very superior stone is procured. 

Of the stone sent to the Belfast district Mr. Grey states: 
“This is very excellent stone, of light colour, free from iron, 
very durable, hammers and tools well; works freely for dressings, 
sills, and quoins, as well as for rubble work. Has been used in 
Coleraine Church; in Parish Church, Northern Bank, and Pres- 
byterian Church, Kilrea; Protestant Hall, Belfast; and in the 
Coastguard Stations at Moville and Rathmullen, for-quoins, sills, 
and dressings.” 

They have also been used in the Diocesan Seminary, London- 
derry; in the Lunatic Asylum (see Gortnagluck List, Co. Tyrone, 
page 608) ; in St. Columb’s Cathedral and the Roman Catholic 
Parochial Hall. The Provincial Bank, Ballyshannon, Co. Donegal, 
was to have been faced and dressed with Mount Charles stone ; 
but, when it was half up, the supply seems to have failed, and 
the cut-stone in the upper portion is from Dungiven. Of the 
latter Mr. J. Cockburn writes: ‘“‘The stones seem to have been 
carefully selected, as they are better than most specimens of it to 
be seen elsewhere in evenness of texture, firmness, uniformity of 
colour, and freedom from sand holes.”” They have been used for steps 
and dressings in different private residences in north-east Donegal. 

Glenconway. Hight miles from Limavady.—Yellowish ; easily 
worked; has been used in Limavady, Londonderry, and else- 
where. 


084 Scientific Proceedings, Royal Dublin Society. 


Walk Mills. Three miles east and south-east of Limavady.— 
Brownish and reddish flags, from 8 to 5 inches thick. 

Triasstc.—Reddish and orange ; locally called “‘ Red Free ;”” 
very easily worked, but friable, and in general not durable; used 
locally. 

J uRassic.—Thin-bedded sandstones occur as subordinate layers 
in the band of Lias that margins in places the Cainozoic plateau 
of Antrim dolomyte. They have been used as flagging, but are 
soft, and liable to get damp. Formerly they were in great request 
as scythe stones, a considerable trade in them having been carried 
on at Magilligan. 

Creracrous AND Hocene.—The arenaceous adjuncts of these 
rocks are the Frinrs and Acatzs, the latter occurring principally 
in the lower Eocene Conglomerate. Anciently they were wrought 
into war implements. They have been previously mentioned in 
the description of the Co. Antrim (page 534). 

Sanp and GraveLt.—Good pit sand, if well selected, can be 
procured near Coleraine, and Magherafelt, in Bishop’s Demesne, 
Derry, and in the vicinity. Good river sand is found near Derry 
and near Newtownlimavady, being very good along the River Roe. 

A fair quality of sea sand is procured from the sand-banks at. 
Magilligan. 

In Londonderry, in 1820, a glass manufactory was established 
in the old sugar refinery, Sugar-house-lane, but was closed after a 
few years. It is not now known where they got their sand. 


LONGFORD. 


To the north of the county, coming in from Leitrim and Cavan, 
are Ordovicians, which are margined by Lower Carboniferous Sand- 
stones. At Granard, however, there are peculiarities, the sandstones 
being interstratified with the limestones. In the neighbourhood 
of Longford also, south-west of Ardagh, there are outlying expo- 
sures of Ordovicians associated with more or less marginal belts of 
Carboniferous Sandstone ; while in the Cap there are also arenaceous 
rocks, some of which will be mentioned. 

Orpovictan.—Here, as elsewhere, the grits and sandstones do 
not seem to be known, except locally, as none of them appear to 
be eminently suited for cut-stone purposes. 


Kinaunan—On Irish Arenaceous Rocks. 589 


Carsonirerous.—These rocks, although of small extent, are 
locally in fair request, notwithstanding that excellent limestone 
can. be easily obtained in the neighbouring counties; and, as men- 
tioned in the previous Paper, the latter class of stone for some 
years has been principally sought after for cut-stone purposes. 

In the Granard district, in general, the stones are whitish-grey 
or bluish, splintery, and hard to work, and are seldom used, 
except for walls. There is, however, in some beds, a better class 
of stone, of a yellowish colour, that works freely. 

Ballinacrow. Two miles from Granard.—Yellowish; quartz 
grains, little cement, micaceous ; spotted with iron and calcareous 
matter. 

Dalystown. Four miles from Granard.—Steel-grey; hard, 
silicious; spotted with calcareous matter. 

Ballinamuck. Twelve miles from Granard. — Yellowish ; 
coarsely granular, white grains in an argillo-silicious cement. 
Here are also to be obtained hard flags of good sizes, that have 
been used in Longford. 

Ardagh.—Greyish-white ; open and porous, white grains in a 
silicio-caleareous cement; ferruginous spots; used in Granard. 

Glack. Near Longford.—Over a large tract of country there 1s 
a coarse conglomerate. On this conglomerate, in the quarries near 
Longford, there are sandstones. The latter are yellowish, but 
becoming white on exposure; coarse, white quartz grains, with 
yellowish argillo-silicious cement; can be raised in blocks, 6 feet 
square, and 4 feet thick; used for the buildings in the town, and 
also wrought into millstones for oat bruising. 

Edgeworthstown.—In the Calpy limestone are good flags, very 
similar in appearance to the Carlow flags. 

Sanps anp Gravets.—Pit sands procured near Granard, Bally- 
mahon, and Newcastle; elsewhere scarce. 


LOUTH. 


The major portion of the county is occupied by Ordovicians. 
To the north, at Carlingford, and on the south-east flanks of Sheve- 
Foye, are small thicknesses of Oarboniferous Sandstone, and also to 
the westward, near Ardee. 

In the Oxpovicrans there does not appear to be any quarry of 


086 Scientific Proceedings, Royal Dublin Society. 


much note, although in various places there are quarries. "When 
of fair sizes, they are worked for local purposes. Although the 
stones are hard, some of them dress fairly well. 

CarBoniFERouS.—According to Traill, the sandstones near 
Carlingford are not of much value. (G. S. IL) 

Kilpatrick. Near Ardee.—Grey, weathering pale-brown, cal- 
careous cement; used for building purposes. Similar rocks are 
exposed in the bog, two miles N. N. W. of Ardee. (G. S. IL) 

In the celebrated ecclesiastical ruins of Mellifont and Monaster- 
boice the sandstone dressing used, according to Wilkinson, seems 
to be Carboniferous Sandstone from the Co. Meath. They and 
the two large crosses at the latter place are in good preservation, 
except some badly-selected micaceous stones. In St. John’s Gate, 
Drogheda, the unequal weathering of sandstone and limestone is 
illustrated. Where the sandstone came from is not known. 


[ Mr. Sharpe, the well-known Dublin builder, who has carefully traced up the sand- 
stones in some of the ancient buildings, is of the opinion, as already mentioned (Intro- 
duction, page 510), that the stones at Mellifont are from Doulting, near Glastonbury. | 


SAND AND GRAvVEL.—Good pit sand occurs near Ardee, and a 
loamy sand near Dundalk. 

River sand is obtained in the Boyne, at Oldbridge, for use in 
Drogheda. 

On the coast are dunes and tracts of A#lolian sands, at one time 
in request as an agent for making the stiff clays of the county 
friable. They seem now to be very little used; they ought, 
however, to be valuable fertilizers. 


MAYO. 


To the south of Clew Bay are metamorphic rocks, with subor- 
dinate intrudes of granite. These, to the south and eastward, are 
overlaid by Silurian or Carboniferous rocks. North of Clew Bay, 
occupying the north-west portion of the country, and extending 
in a narrow tract eastward by Westport and Castlebar across the 
county into the Co. Sligo, there are also metamorphic rocks and 
granites, which are overlaid either by Silurian or Carboniferous. 

Of the metamorphic rocks in the east and north-west portions 
of the county it has been stated that they are of Laurentian age ; 


Kinanan—On Irish Arenaceous Rocks. 587 


‘but, as already pointed out, this is highly improbable, if not 
impossible. Some of them, undoubtedly, are the equivalents of 
the Ordovicians, and the rest are probably the equivalents of the 
Arenig, or possibly part of the Cambrian. North of Balla, to the 
eastward of Castlebar, is a small outlying mass of Coal-measures. 

CampriAn, or Arentc.—These, as just now mentioned, are, 
for the most part, metamorphosed into schist, gneiss, or granite. 
There are, however, some quartzytes and quartz-rock, capable of 
being raised in large blocks suitable for rough work ; but they are 
seldom used, as other stones, as easily procured, are preferred. 
They can also be utilized as road metal. 

Orpovictan.—These, like the older rocks, are in general meta- 
morphosed; but in places, more especially to the eastward, north 
of the eastern continuation of the Erriff valley, they are not. In 
the unaltered portions there are some very massive grits and sand- 
stones that would be valuable for piers, foundations, and such 
rough massive work, but that they are backward and very inacces- 
sible. There is also a pebbly quartzyte, very suitable for piers ; 
but it does not appear to have been much utilized. 

Between Foxford and Swinford are flags of great dimensions. 
Symes considered that they are due to water freezing in the joints 
that split off huge plates, some as large as the side of an ordinary 
—eabin. They might be more utilized than they are. 

In the north-west of the county (Erris), ‘‘ between Benmore 
and Belderg Harbour, also along the coast of Broad Haven, between 
Dawish Cellar and Blind Harbour, flaggy quartzytes, in unlimited 
quantities, light-browns and greys, may be had of any sizes and thick- 
nesses; these are well suited for street flagging, and some beds are 
easily and cheaply wrought into paving setts. ‘The flags between 
Dawish Cellar and Blind Harbour could be shipped from either 
- Gubatnockan or Belmullet, and those of Benmore from Belderg. 
lt is proposed to join the latter quarries by a tramway to the 
harbour and erect a pier there.”—(A. If Henry.) 

Sinurtan.—These rocks are both of the ordinary and “ Old 
Red Sandstone” types, the latter predominating, and consisting, 
for the most part, of purplish or reddish conglomerates and sand- 
stones, while the others are principally shades of grey, blue, and 
green argillaceous rock, in which are grits and sandstones. In one 
tract, east and south-east of Louisburgh, they are in part meta- 


588 Scientific Proceedings, Royal Dublin Society. 


morphosed. Some of the purplish sandstones and conglomeritic 
rocks can be raised in large blocks, and would be suitable for cut- 
stone purposes; but, on account of the facilities for procuring 
excellent limestone, they, in modern times, have been rarely 
thought of, except near Newport, where some of them have come 
into favour. In 1845, Wilkinson thus writes of the sandstone 
then in favour in that town :—‘‘ It varies from a conglomerate or 
coarse-grained sandstone to a very hard red and brown and 
whitish-coloured grit. This stone is now generally used for all 
purposes, and is quarried within a mile of the town on the east. 
The bridge of Newport has the spandril erected with a fine red- 
coloured grit obtained from the neighbouring mountains.” 


[In this neighbourhood the Silurians of the ‘‘ Old Red type”’ and the Lower Car- 
boniferous Sandstones are rather mixed, being often very similar in colour and texture, 
so that, except from personal examination in the quarry, one cannot be distinguished 
from the other. Most, if not all, of the sandstones mentioned by Wilkinson as used in 
Newport seem to have come from the tract of Silurians a little eastward of the town ; 
but some of them may possibly have been obtained from the Lower Carboniferous. 
Sandstones of the vicinity. ] 


To the east of the county, between Charlestown and Ballagha- 
derreen, there is a tract of Silurians. In this the rocks above 
and below are of the ‘‘ Old Red Sandstone” type, while between, 
are green sandstones, with subordinate calcareous and shaly beds 
that contain Silurian or Llandovery fossils. 


[The green sandstones are peculiar, because, except in colour, they are identical in 
composition with the rocks above and below them. The fossils occur in three horizons. 
Those below are of Llandovery types; the middle beds contain fossils of Wenlock 
types, while in the upper beds they are again of Llandovery types. This, therefore, 
is an example of the places in which fossils typical of English groups cannot be taken 
- as a positive indication of age ;—these rocks, as suggested by Griffith, Jukes, and 
Foot, are probably in part the equivalents of the ‘‘ Dingle beds’”’ and the ‘‘ Glengarriff 
grits’’ of the counties of Cork and Kerry: that is, the upper beds of the Silurian 
closely allied to the Devonians or the Passage Beds between the Silurian and the Carbo- 
niferous. | 


In both the rocks of the reddish and greenish types are some 
good workable stones, that have been extensively used for building 
purposes, both in Ballaghaderreen and Charlestown. Some of 
them seem to be capable of producing good dressed work; but, as 
they have been principally used in rough walling, their capacities 


Kinanwan—On Irish Arenaceous Rocks. 589: 


have not been fairly tested; more especially as only the surface. 
stones have been used in these buildings. 

CarponiFrERous.—For the most part these occur as bands mar- 
gining the older rocks, but in places in the limestone they are 
interstratified ; some of them are fit for all cut-stone purposes, 
although none of them have come very prominently forward on 
account of the good-class limestone of the county, which is pre- 
ferred by the workmen. 

Meelick. Near Killala.—Brownish grey ; quartz-grained, with 
little cement; easily worked, large blocks can be procured; ex- 
tensively used in the piers and quay-wall at Ballina, and in the 
neighbourhood. 

Crossmolina. A good freestone to the westward of the Deel 
river. 

Between Foxford and Swinford are flags, some so thin that 
formerly they were used for roofing instead of slates. 

Farm quarry. At Westport there is a peculiar stone. It 
occurs in the upper beds of the limestone quarry. It is thin- 
bedded and square, on account of the systems of joints that cut 
across it, these joint-lines being glazed with a film of quartz. One 
system of the joints is perpendicular, the other slightly oblique ; 
but if the stones are properly selected and laid, the natural faces. 
produce a perfectly even perpendicular wall, having a surface that 
looks like finely-cut limestone, laid in narrow courses; they were 
used in Lord Sligo’s house at Westport, the dressings and other 
cut-stone being of hmestone. 

In the new church at Westport, Carboniferous Sandstones were 
used; but, unfortunately, dry stones and newly-quarried stones 
were mixed promiscuously, and consequently the drying and 
shrinkage of the latter have caused ugly open joints and uneven 
settlements. 

The old church and round tower at Awghagower were built of 
the local red stone. It seems to have worked freely and well, but 
is not very durable. 

Pouilsharavogen. Six miles from Swinford.—This stone, although 
at the east of the county, is in general similar to that described as 
occurring at Meelick, near Ballina. In places, however, the stone 
is conglomeritic or pebbly ; and, under such circumstances, Wilkin- 
son considered it better adapted for cut-stone purposes. This. 


090 Scientific Proceedings, Royal Dublin Society. 


‘stone has been very generally used in Swinford, Claremorris, and 
the neighbourhood, and of it was built the round tower of Meelick, 
south of Swinford (not the Meelick previously mentioned, near 
Kcillala), of which the stones are now in good preservation. 

Stones that have been used for flagging are recorded as fol- 
lows :—Thin-bedded sandstones at Carrickryne, Ballycastle, Meelick, 
and Carns; used in Ballina. Glenisland, soft when quarried, but 
afterwards hardening; used in Castlebar; Gormancladdy, Killedan, 
Balla, and Carrowcastle; used in Swinford; and Curveigh, for use 
in Westport. There is a very thin, smooth flag, called “‘ Dunmore 
slate,” raised principally in the Lower Carboniferous Sandstone of 
Sheve-Dart, near Dunmore, partly in counties of Mayo and Galway. 
These, in old times, were extensively used in place of slate, as will 
be seen on the old houses in Castlebar, Crossmolina, Ballinrobe, 
and other places. This “slate” has been previously mentioned in 
the county Galway. Besides Slieve-Dart, it also occurs in some of 
the other localities for Lower Carboniferous Sandstone, as between 
Foxford and Swinford, but was not as extensively worked as in 
Slieve-Dart. 

Sanp AnD Gravet.—Good pit sand for building purposes can 
generally be easily obtained in the low country ; the Eskers in the 
“Plains of Mayo” affording not only that, but good sand for 
manure, and gravel for road metal. The river sands are also good ; 
they occur in various places along the rivers and streams. There is 
also sea sand in different places; near Ballina there is a consider- 
-able supply. 

On the west coast of the barony of Murrisk there are olian 
-sands, some parts of which are in cultivation and yield good crops, 
‘especially potatoes. ‘There are also extensive tracts near Blacksod 
Bay, and smaller ones near Broadhaven; these seem to have been 
extensively cultivated formerly for potatoes and barley, but not 
so much of late years. 2 

A. good glass sand occurs near Belmullet, which has been used. 
a little for glass manufacture. 


KonanaAn—On TInish Avenaceous Rocks. 59k 


MEATH. 


To the east of the county, near Balbriggan, coming in from 
the county Dublin, to the north-east coming in from Louth, and 
to the north-west coming in from Cavan are Ordovicians—the last 
two being connected by the strip of similar rocks in which Kells is. 
situated. In general sandstones are not exposed at the base of the 
Carboniferous, and in places there appears to be no room for them; 
they, however, appear near Oldcastle, to the westward of Kells, 
and between Navan and Drogheda; while Mr. Cruise states there. 
is a small patch of conglomerate on the Ordovicians at Stramullen, 
at the mearing of the Co. Dublin to the west of Balbriggan. 
Elsewhere beds of sandstone have been observed interstratified 
with the limestone. 

On the Carboniferous Limestone to the north, near Nobber, 
between Drogheda, Navan, and Maynooth, and near Trim, are 
outlying patches of Coal-measures in which are fair stones. At the 
extreme north of the county, near Kingscourt, there is a small 
tract of Trias. 

Orvovician.—None of the sandstones or grits of this age seem 
to have been, or are at present, in favour for cut-stone purposes, 
nor have they been much used for general work, as the associated 
slate rocks, except in the tract near Balbriggan, are eminently 
suited for such work, and in old times and subsequently were, and 
are, much used. 

CarsonireRous.—In the small patches of Lower Carboniferous 
Sandstone, near Oldcastle and westward of Kells, there are sand- 
stones of reddish, brownish, and yellowish shades of colour. These 
were used as quoins in the old church of Kells, while the round 
tower was nearly entirely built of them. ‘They are not very dur- 
able, but are of an even texture, and have weathered evenly. 
Between Navan and Drogheda, along the margin of the Carboni- 
ferous rocks very similar stones have been quarried in places. 
They vary a little in colour; some are streaky or variegated, while 
they may be argillaceous or quartzose, some being very hard. They 
are not a good class of stone, yet they are very generally used, 
and the Round Tower of Donaghmore was built of them. Here, 
as also in the localities to the westward, some beds are capable of 


O92 Scientific Proceedings, Royal Dublin Society. 


being wrought into flags, and these have been used in Kells and 
elsewhere. 

Hayestown. Fourteen miles from Kells.—Brownish to yel- 
lowish; quartz grains; calcario-silicious cement; not very durable ; 
works easily. 

To the north-west of Navan there are some sandstone quarries 
locally used. 

In the tracts of Coal-measures there are some good stones 
reported; but if local use is ignored, none of them have been 
worked except in the Nobber district, and there only sparingly, 
as the bad roads and accommodation make the quarries difficult of 
access. Some of the thin-bedded sandstones, as near Garristown, 
make good and strong flags; English flags, however, being easily 
and cheaply obtained, seem to have prevented their being much 
worked. 

Cortubber. Near Kingscourt; greyish-white; quartz grains; 
very little felspathic cement; finely granular; works freely and 
well. 

Carricklick. Seven miles south of Carrickmacross. Greyish- 
white, but unevenly coloured; silicious grains; very little cement ; 
fine-grained ; works freely and well; large blocks can be procured. 
Lough Fea House was built of this stone; used extensively in 
Carrickmacross. A limited quantity of flags can be raised here, 
which can be manufactured into hearth-stones. 

Trras.—The “Red Free” of this area seems to have been 
very little used, and only locally. 

Sanp AND GraveL.—Pit sand, excellent for building purposes; 
is very general; although sometimes it is loamy. In the cutting 
for the Meath Railway an inexhaustible supply of sand and 
. gravel suited for road purposes is exposed; some of it is good 
manure sand, but is not much used, so much of the county being 
under grass. 


MONAGHAN. 


Occupying all the central portion of the county are similar 
Ordovicians to those that have been described in Armagh and 
Cavan, which lie respectively to the north-east and south-west. 
Here, as in those counties, the grits are very little used, the 


Kinanan—On Trish Arenaceous Rocks. 593 


associated slate being much preferred for general purposes ; 
although not capable of being used in dressed work. Fair flags 
have been raised in a few places, as in Dartree, which lies north 
and north-west of Clones. 

To the south of the county, in the neighbourhood of Carrick- 
macross, is a small tract of Carboniferous rocks, principally lime- 
stone: this is overlaid by Coal-measures, and the latter, uncon- 
formably, by Triassic rock ; the principal portions, however, of the 
outlier of the later rocks are situated in the neighbouring counties 
of Cavan and Meath. 

To the north of the county there is a second area of Oarbo- 
niferous limestone. And margining this to the southward, and 
lying on the Ordovician, is a narrow tract of Lower Carboniferous 
Sandstone, on which Clones and Monaghan are situated; while 
further northward are the rocks of the “ FERMANAGH SERIEs,” or 
Lower Coal-measures of the Fermanagh type (ermanagh, p. 560). 

In the Fermanagh portion of the Slieve-Beagh district there 
are different quarries of former and present note; but eastward in 
this county there are none, although the “‘ Fermanagh Sandstones”’ 
extend into it; also in places on the flanks of Carnmore superior 
stone have been procured. In Castleblayney, Monaghan, and 
Clones, most of the stones used for cut-stone purposes were brought 
from the quarries in the Fermanagh portion of Carnmore or quar- 
ries in the Lisnaskea district, or from the Clogher district (Lower 
Carboniferous Sandstone), Co. Tyrone. In the south of the county, 
at Carrickmacross and its neighbourhood, the sandstones have been 
brought from Carrickleek, Co. Meath. 

Carnmore.—Yellowish-reddish. Chiefly quartz grains; fer- 
riferous spots; somewhat friable; works freely. On the summit 
of the mountain there was an extensive quarry for millstones ; 
which, after being wrought in the quarry, were let roll down 
the mountain, and conveyed to Scotstown, where there was a 
depdt. On the northern side of the hill there is a soft whitish 
freestone, and on the southern a hard reddish grit. 

Knocknatally.—A. good freestone, formerly extensively quar- 
ried for use in the neighbourhood. 

Emyvale. Southward of.—Fermanagh Sandstone (?), used in 
Monaghan. 

In the parish of Donagh, to the north of Monaghan, excellent 


594 Scientific Proceedings, Royal Dublin Society. 


freestone was formerly quarried in different places, and the great 
entrance to Caledon House was constructed of this stone. 

Sanp AND GraveL.—Pié sand of a good quality is very 
general in the county, while river sand can be obtained in the: 
rivers and streams. Gravel can be procured from the Hskers: those 
in the Tehallan district being noted for their wearing qualities, 
they for the most part being made up of hard jasperry pebbles. 


[In the high level portions of the counties Monaghan, Tyrone, Fermanagh, &c., 
there are gravel ridges that have been called ‘‘ Eskers’’; they are not, however, true 
Eskers similar to those of the great central plain of Ireland. The true Eskers are of 
marine origin, the ridges being due to the colliding of tidal currents, and all occur 
below fixed levels, which are the maximum heights of the Esker Sea; their height 
varying a little, as in the seas of the present day, the tides rising higher in the bays 
than in the open. The gravel ridges of the high levels, and in some places even on 
the lower levels, of the above-named counties, are for the most part of a different 
origin, being similar in aspects to the sands, gravels, and other drifts found in the: 
valleys and plains and slopes associated with the Alpine regions, such as those found in 
connexion with the ‘‘ Foot Hill’’ of the Canadian Rockies. In some of the low counties, 
Monaghan and Fermanagh, &c., the marine and glacial gravels seem in part to be- 
mixed or to graduate into one another. | 


QUEEN’S COUNTY. 


The greater portion of this area is occupied by Carboniferous- 
Limestone ; but to the north-west, surrounding small exposures of 
Ordovicians, are tracts of Lower Carboniferous Sandstone ; while to. 
the south-east, in Cullinagh and the northern portion of Slieve- 
margy (Letnster CoaL-FIELD) are Coal-measures. The Ordovician 
grits are rarely used, even for local purposes, the associated slates. 
being preferred. 

Lower CarsoniFrerous SanpstonE.—In colour these are from. 
whitish-yellowish to brownish, and streaked. Some are argilla-. 
ceous, they not being as durable as those having a silicious cement. 
These sandstones have been very generally used in the neighbour- 
hood. ‘They have been largely used in Mountmellick, a soft, sili- 
cious stone in that neighbourhood being at one time extensively 
manufactured into chimney-pieces and hearthstones. In the 
churches of Abbeyleix, Slieve-Bloom sandstone and Ballyullen 
limestone were used in the dressings. Ballyfin House and the 
chief entrance lodge in the Slieve-Bloom district were built of locak 


KinaHan—On Irish Arenaceous Rocks. 598d 


stone; in the latter are some hastily selected, which have stood 
badly. At Clonaslee and Rosenallis there is a thin-bedded stone, 
very extensively used in the county for flagging; they cannot be 
obtained of large sizes, but are very dry; when first raised they 
are soft, but rapidly harden. Stones for cut work can also be 
procured; but, on account of the ungainly shapes of the blocks, 
are expensive to dress. 

Clara Hill, Clonasiee.—Yellowish ; very silicious ; fine-grained ; 
micaceous ; ferriferous spots. 

Tinahinch. Three miles from Clonaslee. — Greenish-white ; 
silicious-grained ; argillaceous cement; partially carbonaceous 
matter. 

Glenbarrow. Three miles from Clonaslee.— Grey ; silicious- 
grained ; ferriferous spots. 

Rosenallis Mountain. — Westward of Mountmellick. Very 
similar to the Clara Hill stone. 

Baillysally. Ten miles from Roscrea, where it has been much 
used.—Yellowish to lightish-brown. Is soft when raised, but 
hardens on exposure. Works easily. 

CoaL-MEASURES.—In general, these stones are not now looked 
after, yet that they are capable of good work can be seen in the 
previously-mentioned doorway of Kalleshin Church, Co. Carlow 
(page 537). In some of the ancient buildings a thin-bedded grit 
has been used, also in latter years at Clogerennan. As those 
used at Cloggrennan were not suited for cut-stone purposes, other 
material was used for the dressings. 

Cloggrennan.—Dark-greenish grey; fine-grained; close; dense ; 
flagey ; not good for cut work. 

Corgee and Hollypark. In the Collieries.—Good strong flags 
were formerly rather largely worked. ‘These flags, on an average, 
could be raised 12 feet square, the largest raised being 22 feet 
long and 12 feet wide (G’. S. IL) 

' Derryfore. Hast of Abbeyleix.—Olive, thick sandstones and 
flags. 

SanpD AND GrAvEL.—Both of excellent quality occur plenti- 
fully in the Eskers. In some of the streams coming down from 
both the Lower Carboniferous Sandstone and Coal-measure hills 
there are sharp silicious sands. 


SCIEN. PROC. R.D.S.—VOL. V., PT. VII- 258 


596 Scientific Proceedings, Royal Dublin Society. 


ROSCOMMON. 


To the north and south-west of Lough Allen are Coal-measures— 
a small portion of the Connaveut Coat-Fietp. To the southward 
of these, extending from the north-west margin of the county 
eastward, past. Lough Key nearly to the Shannon, are Stlwrians 
of the “ Old Red Sandstone” type, which are margined southward 
and eastward by Lower Carboniferous Sandstones. To the west of 
the county, both north-east and west of Castlerea, and farther 
south-west in Slieve-Dart, are patches of similar rocks, as also 
south-west of Roscommon; while to the north-east of the same 
town, in a south-west and north-east direction, is Slieve-Baun, 
near which small exposures of Ordovicians are margined by Lower 
Carboniferous Sandstone. 

The Orpovictan grits, which are of small dimensions,-are more 
or less inaccessible, and are very little used, even locally. 

Srnurtan.—These occur in the Curlew Mountains. Of these 
there is a great thickness, and some of them are fair working 
stones; but in general they are hard, gritty, and of bad working 
quality and colour. ‘They are not in request, as limestone is pre- 
ferred; and if sandstone is required, those belonging to the Lower 
Carboniferous Sandstone are used. 

Associated with these sandstones are felspathic tuffs. Although 
these are more of the nature of argillaceous than arenaceous rocks, 
they ought here to be mentioned, as in places the one graduates 
into the other. Some seem as if they would cut well; but as 
they are in general in somewhat inaccessible or inconvenient places, 
they have only been used for farm purposes. 

Lower CaRBonirerous Sanpsrone.—In the different exposures 
of these rocks there are stones of more or less note. At Tarmon, 
near Boyle, there is a bluish-grey stone, hard and compact; but, 
on account of the numerous joints, it is incapable of being raised 
in large lengths. The strata varies from 10 to 24 inches in thick- 
ness; it has been used in many of the buildings in Boyle, but is 
more suitable for rubble than cut-stone purposes. 

St. John’s Hole. . An historical quarry.—This lies north of the 
river near Boyle. Greyish; good, but hard; hasfbeen used ex- 
tensively in Boyle and the neighbourhood, as in the bridge and 


Konanan—On Irish Arenaceous Rocks. 097 


other public and private buildings. According to Wilkinson, it 
was also used in the old house of Rockingham that was burnt 
down some years ago; the new house, built in 1863 and 1864, is 
of limestone from Ballinafad, Co. Sligo. 

In the bed of the river adjoining “St. John’s Hole”’ is said to 
have been situated the quarry from which the stones were pro- 
eured to build Boyle Abbey. Of this ancient structure, Wilkinson 
writes :—“ Excellent work of every kind, from common dressed 
stones to carved mouldings and ornaments, and its lofty arches 
display a skill in construction far superior to the present day. 
The stone has resisted exposure to the weather well, some of the 
marks of the tools being still visible.” Further, he states in refe- 
rence to the site of the old quarry :—“ It is likely that by well- 
directed efforts the bed of the river was temporarily diverted in 
order to get at stone which, from being constantly saturated, had — 
not become so hard as that which was comparatively in a dry 
position.” 

[This raising of stones out of the bed of a river or stream seems to have been not 
uncommon with the early builders, as in different places holes are pointed out so 
situated, which tradition states were quarries where the stones were procured for 
adjoining structures. Besides other places, such is the case in the river at Drombogue, 
‘In the parish of Kilmacrenan, Co. Donegal, as from an excavation in the bed of the 
stream it is said the stones to build the adjacent Abbey of Douglas have been procured. 


A few years ago, during a dry summer, this hole was pumped out, and a rude set of 
steps were found from the surface to the bottom. | 


In this county, as is so common elsewhere at the present time, 
the masons prefer the limestone for cut-stone purposes, so that the 
sandstone is in general only used for walling and rubble work, as 
it is easily roughly squared ; in some cases it is used for quoins, 
window-sills, steps, and such like, while from St. John’s Hole can 
also be procured excellent flags, with a natural smooth surface, of 
large sizes, and from 5 to 6 inches thick. They, however, are ex- 
pensive and difficult to get at, on account of the necessary pumping 
to keep the quarry dry. 

Felton. Near Boyle.—Yellowish; micaceous; ferriferous. 

French Park. Within a mile of the town.—A silicious sand- 
stone, used for building purposes. 

In the tracts north-east and westward of Castlerea, good stones 


have been raised in different places, but no quarry more than of 
252 


098 Scientific Proceedings, Royal Dublin Society. 


local note has been worked. About three miles from the town 
there is a thin-bedded stone in the bed of the River Suck. It 
is in much request for walling, but is not good for cut-stone pur- 
poses. The stone can only be procured in the summer, when the 
river is low. 

On the tract to the north-east, between the town and French 
Park, there are many large field-stones, or “‘ tumblers,”’ which have 
been extensively used for local works, especially bridges, as they 
split easily. They have been of considerable profit to the occupiers, 
who sold them to those who required them. In the same area, 
near Bellanagane, are finely-laminated stones like the “‘ Dunmore 
slates,’ which in the vicinity have been used for roofing pur- 
poses; they are also found in the north-east portion of Slieve- 
Dart that enters into this county at the extreme south-west. In 
Slieve-Dart are also found the stones formerly so much wrought 
into millstones, but perhaps more in the Galway portion than in 
this county. Eastward of Bellanagane, between it and Mantua. 
is a calcareous stone containing si/iciows nodules more or less similar 
to rough agates and cornelians. 

Sandstone can also be obtained.in the tract to the west of the 
Suck and south-west of Roscommon. 

In the parish of Fuertry there is a quarry of excellent gritstone 
of peculiar solidity and hardness. 

In Slieve-Baun there are some good brownish and yellowish 
stones; but they are now principally used for local purposes, the 
limestone being preferred for dressed work. ‘To the south-east of 
Strokestown, in the south-west portion of Slieve-Baun, there are 
stones particularly adapted for millstones, and fifty years ago they 
were made in considerable quantities for sueR as the adjoining 

counties to the eastward of the Shannon. 

CoaL-MEASURES.—Lhese only occur at the north-west of the 
county. Some of the sandstones are reported to be of excellent 
quality, “ equalling the Tyrone stone”; but they are so out of the 
way and inaccessible that very little is positively known about 
them. rom the Coal-measures, however, are procurable excellent 
flags, somewhat like the Carlow flags, that formerly had a good 
sale; they were principally raised at Keadew and Arigna. 

SanD AND GRAvEL.—In the low country there are Eskers which 
give an inexhaustible supply of excellent pit sand and gravel ; some 


KinaHan—On Irish Arenaceous Rocks. 599 


of these, when of limestone-gravel, are excellent as manure, others 
of a different character are not. River sand also occurs very 
generally. 


SLIGO, 


In the little promontory (Rosses) between Drumeliff and 
Sligo Bays is a small outlier composed of metamorphic rocks ; 
while coming in from Mayo, near the centre of the west mearing, 
and extending north-east across the county, is a portion of the Ox 
Mountain range. These hills, as has already been mentioned, have 
a nucleus of metamorphic rocks, which are probably the equi- 
valents of the Arenig, or possibly of the Cambrian (“ Introduc- 
tion,” page 515; Mayo, page 587), and margining them in places 
are Lower Carboniferous Sandstones. To the extreme south, in a 
small portion of the Curlew Mountains, there are Silurians of the 
“Old Red Sandstone” type, coming in from the neighbouring 
counties, Mayo and Roscommon, which are margined to the south- 
ward by Lower Carboniferous Sandstones. 'To the east of the county 
are Ooal-measures, a small portion of the Connaucur CoAL-FIELD ; 
while to the westward of the main mass are small outliers, lying 
east and west of Lough Arrow. In recent times sandstone has 
not been much used in this county for cut-stone purposes, as in 
general limestone is preferred. 

Camprians (?), ARENIG, AND Orpovicran.—The rocks that 
probably are the equivalents of those of these groups are all more 
or less metamorphosed. There are, however, in them some quartz- 
rock and quartzyte, suited for heavy rough work and for road 
metal. 

SrturtAn.—In the small area included in this county the rocks 
are similar to those adjoining, in the Co. Roscommon. They are 
of inferior quality for cut-stone purposes, being generally coarse 
and hard or argillaceous. They are, however, in places locally 
used. 

CarsonirErous. Lower Carboniferous Sandstone.—Some of the 
beds near Lough Gara, on the south slopes of the Curlew Moun- 
tains, are very similar to the rocks utilized at Boyle, in the Co. 
Roscommon ; but here they do not seem to have been worked. 

Westward of Ballysodare Bay and the neighbourhood of 


600 Scientific Proceedings, Royal Dublin Society. 


Dromore West (parish of Kilmacshalgan) there are quarries of 
freestone. 

To the west of the county, near Kilmacteige, and in other 
places farther eastward, margining the Ox Mountain range on 
the southward, there are in places fair-looking stones, but, as 
previously mentioned, not in request. 

To the north-west of the Ox Mountains, in the neighbourhood 
of Dunowla, and to the south-west thereof, in the tract and strip 
of Lower Carboniferous and Calp (?) Sandstones, some of the 
stones appear as if they might be suited for dressing; but in no 
place are they sufficiently opened up to test their qualifications. 
South-east of Dromore, in Doonbeakin and Ballyglass, flags about 
4 inches thick and up to 6 feet square have been quarried. 

CoaL-MEASURES.—Reports state that some of the beds of stone in 
this area are of good quality. They, however, are so inaccessible 
that they are not properly known. From these hills, however, are 
procured flags of the same class as the “ Arigna flags,” which have 
been largely used throughout the county. 

Sanp AND GraveL.—Pit sand is not very plentiful, and varies 
in sharpness. It can, however, be got good about four miles from 
Sligo. In some of the rivers and streams there is good river sand 
and gravel. Sea sand, which can be collected in great quantities 
along the shore, is an excellent manure for potatoes, but should be 
spread for some months before the crop is put in, as otherwise its 
proper effects are not experienced. In places near the shore-line is 
a stratum of shell sand or gravel, for the most part made up of 
oyster-shells. This, in some places, is at least 60 feet above the 
present high-water mark. This deposit is not only itself a valuable 
manure, but it imparts its fertilizing qualities to the sand above 
_and below it. 


TIPPERARY. 


The sandstones of this county, although now not much heard 
of, have a history; as both in ancient and the present times 
they have been very much used in preference to other kinds, 
even in places outside the margin of the sandstone areas. At — 
Cashel, the older structures (Cormac’s Chapel and the Round 
Tower), are of sandstone, except that in the Tower some of 


Kinanan—On Irish Arenaceous Rocks. 601 


the lower courses are of limestone, but in the adjoining churches, 
which were subsequently built, limestone was used. Some of the 
sandstore hereafter mentioned, if known, would be more sought 
after than it is at present. 

The major portion of the area is occupied by limestone. We 
find, however, to the north-east, a little S. S. W. of Birr (Parsons- 
town), the small but conspicuous hill of Knocksheegowna, mostly 
Ordovician, but margined to the north-east and south by Lower 
Carboniferous Sandstone. Somewhat similarly, in the Arva Moun- 
tains, that lie to the east of the south arm of Lough Derg; in the 
group comprising the Silvermine Mountains and Sleve-Phelim ; 
in Slieve-na-Muck, to the south of Tipperary; and in the portion 
of the Galtees that is included in this county there are Ordovicians, 
margined by Lower Carboniferous Sandstones. The Hill of Cullen, 
to the north-west of Tipperary, is Lower Carboniferous Sandstone ; 
but the rocks of Knockmeeldown, to the south-east of the county, 
are probably in part Devonians, coming in from the neighbouring 
Counties Cork and Waterford. 

To the south-east, in the neighbourhood of Killenaule and 
north-east of it, are Coal-measures, the Hast Munster CoAu-FIELD ; 
while south-westward of the principal area are small, detached 
patches as outliers, which lie north of Cashel; north-east and south- 
west of Fethard; north-west of Clonmel; in Slieve-na-Muck, brought 
down by a great fault against the Ordovicians ; and at Ballyporeen, 
in the valley between the Galtees and Knockmeeldown. 

Orpovician.—These are, in general, in more or less inaccessible 
positions. When otherwise, nearly invariably the grits are in bad 
repute, as the associated slate rocks are preferred for local building 
purposes. : 

Devontans.—The rocks of Knockmeeldown seem to be in part 
the representatives of the Devonians of the County of Cork, that is, 
the Passage-beds between the Silurians and the Carboniferous ; 
while it is not impossible that the lower rocks of the Galtees to the 
northward, and of Slievenaman to the north-eastward, may be in 
part of this age, as the great thickness of the arenaceous rocks 
under the Carboniferous Limestone, as found in all these places, sug- 
gests that the Passage-rocks may be in part represented. 

Knockmeeldown. In different places brownish, reddish, and 
yellowish. Free-working; durable. Has been extensively used in 


602 Scientific Proceedings, Royal Dublin Society. 


Cloghreen, although the latter is in the limestone. A brown sand- 
stone from these hills was used in the ancient castle at Cahir. 

Mount Anglesey. A few miles from Cloghreen.—Brownish- 
yellow; silicious-grained ; argillaceous cement; fine, but granular; 
friable; works freely and well; used for quoins, jambs, and other 
dressings; can be raised in long scantlings, and is capable of long 
bearings. 

In the slopes of the Galtees, included in this area, good stones 
occur in numerous places: they vary from whitish to reddish and 
brownish in colour, some being more silicious than others. In 
general they work freely, and have been used in Cahir in pre- 
ference to the limestone. These were used in the repairs of the 
old castle some forty or fifty years ago. 

CarBoniFrERous.—Lower Carboniferous Sandstone. These stones 
range from coarse reddish or brownish conglomerate to fine sand- 
stone, in shades of light yellow, reddish, and brown or purplish. 
In Clonmel, where sandstone has been most used, it has been pro- 
cured from the other side of the Suir, in the Co. Waterford. A 
similar remark is applicable to Carrick-on-Suir. 

Tinnakilly. Six miles north-east of Carrick-on-Suir.—Yellow 
to brownish ; silicious-grained; with little cement; ferriferous; 
very slightly micaceous. From here, and from Millvale, Co. 
Waterford, have been procured most of the sandstone used in 
Carrick. 

Dundrum. About a mile from.—Yellowish-grey; very good 
texture; suitable for all kinds of dressed work. Mr. Sharp, the 
well-known Dublin builder, states that he believes this stone would 
be very generally used if it were known. 

Drumbane. About seven miles southward of Thurles.— Whitish 
or light-grey ; quartz-grains; argillaco-silicious cement; slightly 
ferriferous ; works freely ; can be raised in large scantlings. Was 
used in the Court-house, Nenagh, twenty miles distant, and in the 
Model School, Clonmel. This, like the Dundrum stone, ought to 
be more generally known; it is an admirable material, more — 
durable than limestone, and very suitable for staircases, as it can 
be obtained in nearly any scantlings, and is capable of long 
bearings. 

Carrick. Near Roscrea.—Light-brown; silicious; very little 
cement; fine-grained; dense. 


Kowauan—On Irish Arenaceous Rocks. 603 


In Roscrea, both in ancient and modern times, the local sand- 
stone has been extensively used. A better quality has been brought 
from Ballinsally, Queen’s County; but the old structures, as men- 
tioned by Wilkinson, seem to be built of the local stone. In Cro- 
nan’s Church and the Round Tower, the original working, as far 
as now preserved, seems to have been good; but the stones were 
not well selected, some now being very much disintegrated. The 
stones in the old castle are fine and thin-bedded, and although not 
so much weathered, they seem to have been weak, as some are 
cracked at their edges. 

In other localities where the Lower Carboniferous Sandstone 
occurs margining the Ordovicians, good stone can in places be 
procured, and has been used locally. The conglomerates and 
coarse sandstones have been in request for bridges and walls, for 
which they are. admirably suited, while in places they were for- 
merly wrought into millstones. 'Thin-bedded stones, used as flag- 
ging in Cashel, are raised near Dundrum, and similar stones for 
flagging in Tipperary have been procured at Shrough, seven miles 
distant; they have also been used extensively in the military bar- 
racks there, and at Fermoy, Oo. Cork.—(James Newstead.) 


[As very superior stones are known to exist near Dundrum, and at Drumbane, 
southward of Thurles, similar veins ought also to occur elsewhere in the county margin- - 
ing the tracts of Ordovicians. But they have not been looked for, the stones of this 
county, as already mentioned, not being in the market, and, except locally, are not of 
note; but if inquired after they would probably be more in request than some now 
sought after. | 


CoaL-MEASURES.—In different places there are good stones for 
walling and rubble; but as they in general hammer badly, the 
quoins, sills, and other stones for dressed work are procured from 
the Devonian or Yellow Sandstone quarries. 

In places in the Killenaule district, below the lowest coal, good 
flags can be raised. 

Sanp anp Gravet.—Near Roscrea, Thurles, and Tipperary, 
are Hskers, from which can be procured an unlimited supply of 
pit sand and gravel. Good sand can also be got near Clonmel and 
Nenagh, and an inferior kind near Cashel. River sand occurs in 
places in the Suir and the other rivers and streams. 

The Esker sands, and also a marly gravel was formerly exten- 
sively used as manure. The latter was called Corn gravel, as it 


604 Scientific Proceedings, Royal Dublin Society. 


gave excellent crops of wheat; but since the change in the climate 
which prevents the wheat from properly yielding and ripening, 
and the consequent falling off in that crop, it is not much used. 


TYRONE. 


This, at the present time, is the premier sandstone country : 
not, however, as regards quantity, but as to the quality to suit the 
present market; and also as to variety, they being of different 
colours, textures, and hardness, and belonging to various Geological 
groups and sub-groups. 

To the northward, extending from near Omagh, north-eastward 
into Londonderry, is the tract of metamorphic rocks, suggested by 
Dr. Hinck as possibly of Lawrentian age; but, as shown in the 
* Introduction” (page 515), more probably the equivalents of the 
Ayeng, or even possibly of the Cambrian. In the vicinity of Pome- 
roy, against these rocks is a small tract of rocks that possibly may 
in part represent the Llandovery, which, as given in the Table of 
Strata (Part 1., page 204), are the Passage-beds between the Silu- 
rian and the Ordovician ; these rocks, however, are evidently nearer 
allied to the last than the first. 

On the southward of these strata is a considerable and wide 
tract of Silurian, of the “ Lower Old Red Sandstone” type—the 
eastern portion of the area already mentioned when describing 
Fermanagh (page 560); and still further to the southward, in 
places margining these rocks, is a narrow band of Lower Car- 
boniferous Sandstone. 

North of the Tyrone Coat-Fiexp there is a tract of Calp Sand- 
stone brought up by a fault, while there is a second south-west of 
Dungannon (Dungannon Park). Farther south-westward, north- 
east and south-east of Aughnacloy, are tracts of somewhat similar 
rocks that have been classed among the Calp Sandstone; but it 
should be pointed out that they are also more or less like the | 
rocks of the Mermanagh Series (Lower Coal-Measures) of the Slieve- 
Beagh district, counties Fermanagh and Monaghan (page 561) ; 
while in the neighbourhood of Aughnacloy they appear to join 
into one another. It seems possible that in the latter neighbour- 
hood the geology has not been properly worked out, and hereafter 
(north of the Tyrone Coal-field), it will be found that the Coal- 


Kinaunan—On Irish Arenaceous Rocks. 605. 


measures and Calp Sandstone are brought together by a fault, a 
downthrow to the south-eastward. 


[All these lithologically similar rocks to the north-east of the Blackwater (Aughna- 
cloy) are called on the new maps Calp, while west and south-west of that river they 
are called by the unappropriate English sub-group names, Yoredale beds and Millstone 
grits. | 


The well-known sandstones of the Co. Tyrone are all of Car- 
boniferous age; but they may belong to the Lower Carboniferous 
Sandstone, the Calp, or the Coal-measures. The rocks in the 
neighbourhood of Aughnacloy, as already mentioned, may belong 
to either of the latter groups; here, provisionally, they will be 
described with those of the Calp. The Calp is of the two types, 
the ordinary, and the “ Ulster type;” the rocks in these will be 
given separately. 


[The subdivisions of ‘“ Upper and Lower Calciferous Series’’ adopted in the Geolo- 
gical Survey Memoirs are only lithological ; the reddish pebbly rocks forming the latter. 
These dark-coloured rocks may, however, occur on any geological horizon, their colour 
and composition being solely due to islands, or other shore lines in the Carboniferous. 
sea, they always being found adjoining a protrude of the older rocks. | 


These rocks have been used in the county—very generally in 
Dungannon, Coalisland, Clogher, Omagh, Cookstown, Castlederg, 
and Caledon; while in Strabane, and other places in the schist 
regions, they are used for quoins and other dressed-stone purposes. 
At Baronscourt they were used, except the Portland stone for the 
staircases, and in a few other places. Out of the county they have 
been extensively used for cut-stone purposes. 

Near Benburb, at the south margin of the county, are sand- 
stones that have been said to be of Permian age; but on account 
of the assemblage of fossils in these and the associated rocks, and 
also of their position, Baily and the writer have suggested that they 
must belong to the Carboniferous. 

In the northern portion of the county, at Cookstown and Kil- 
dress, at Omagh and south-east of Strabane, are tracts of Calp, of 
the “ Ulster type” (vide “ Introduction”); while north of Dun- 
gannon, and further northward at Annaghone are Coal-measures 
(Tyrone Coau-FreLps). Near Cookstown and Coagh, and extend- 
ing southward past Dungannon into the Co. Armagh, Zias (“ Red. 
Free”’) is found. 


606 Scientific Proceedings, Royal Dublin Society. 


The Orpovictan grits are very little used even for local pur- 
poses, the associated slates being preferred for ordinary work. At 
Strabane, Castlederg, and other places in the north of the county 
the metamorphosed Ordovicians (Micalyte, Argillyte, &c.) are used 
for walling, the cut-stone work nearly invariably being Carboni- 
ferous Sandstone. Near Strabane flags are procured. 

Sirur1an.—These range from conglomerate to fine sandstones ; 
in general being silicious, but often argillaceous, or even carbona- 
ceous. Similarly, as in the Co. Fermanagh, they have been used a 
little for cut-stone purposes, and are very suitable for coarse work, 
such as bridges and walls. Formerly, in some places, the very 
silicious varieties were wrought into millstones. 

Lacagh. About two miles south-east of Fintona.—Purple and 
reddish ; conglomeritic; yields sills and quoins; used in the build- 
ing of Fintona new bridge. 

Dungoran. Near Fintona.—Yellowish; grains white quartz ; 
a little argillo-silicious cement. 

Raweagh. Near Fintona.—Brown; makes good rubble; used 
in Raveagh House. . 

Dundiven. ‘Three miles south-west of Fintona.—Cream colour, 
greyish-white, and greenish-grey. Rather argillaceous and fel- 
spathic; partly calcareous; granular ; fine-grained; free-working. 

Lackagh. Three miles from Fintona.—Dark-purplish ; semi- 
erystalline. 

Pomeroy. A mile from.—Dark-purplish grey ; semi-crystal- 
line; granular; micaceous; works fairly well. 

Lower Carponrrerous SANDSTONE.—Generally greyish or yel- 
lowish in colour; some, however, reddish; more or less silicious ; 
unequal grained; works freely, but soon wears the tools. In 
places some of the more silicious varieties were wrought into mill- 
stones. 

Derrynascope. One mile from Augher.—Greyish and yellow; 
silicious-grained, with, in some beds, a reddish felspathic cement. 

Dernasill. Four miles from Augher.—Greyish-white to yel- 
lowish; silicious; argillo-silicious cement; granular; micaceous; 
in some beds ferriferous. 

Altaven. Five miles from Augher.—Greenish-white, with 
yellow seams; very quartzose; unequally grained. 

Ballymagowan. One mile from Clogher.—Yellowish ; white 


Towauan—On Irish Arenaceous Rocks. 607 


silicious grains; a little felspathic cement; when ferriferous they 
have a reddish tinge. 

Elderwood. Three miles from Fivemiletown.—Reddish ; sili- 
cious grained ; felspathic cement. 

Cavey. One mile from Ballygawly.—Yellowish; silicious; a 
little cement; fine-grained; ferriferous. The conglomerates near 
Ballygawly were formerly wrought into millstones and flax- 
crushers. 

Carp (Ulster type)—Many of them are beautiful stones— 
creamy or yellowish in colour, or with a bluish tint. In general 
they are free-working, open-grained, and capable of producing 
good work; some, however, are not suitable for heavy bearing. 
From the ancient buildings in which they were used they seem 
to be very durable. 

These sandstones occur in limited thicknesses of strata, the 
“‘over-bearing’”’ or cover-rocks being limestones or shale. This, as 
the quarry is worked in on the dip (which is low) of the stone, 
very often becomes excessive, so that the expense of removing it 
may become greater than the value of the stone. In other quar- 
ries the good stone occurs in more or less lenticular or other masses, 
adjoining which the stones are inferior. For these causes, quarries 
once famous are now worked out or abandoned. 

Cookstown. In different quarries in the vicinity of.—Yellowish, 
creamy, or with a bluish tint; silicious-grained; a little argillo- 
silicious cement; open-grained; slightly micaceous; soft, and not 
suitable for heavy bearings. Mr. Dickinson states:—‘‘Some of 
the beds are hard and excellent for all kinds of masonry.”” From 
Tamlaght quarries were procured the stones used in the Lower 
Bann navigation works, while those used in the building of Killy- 
more Castle came from the quarry nearly a mile north-west of the 
workhouse. Stones from the Cookstown quarries were also ‘used 
in the Provincial Bank, Belfast: a light, tough sandstone, hard to 
dress, and does not stand.’—(W. Grey.) 

Kildress. Stones very similar to those of Cookstown. 

Loughrea. South of Cookstown.—Similar stone. 

Trinmadan. Nearly two miles from Gortin.— Yellowish ; quartz 
grains; argillo-silicious cement; granular. 

Carrickmore, four miles from Gortin; Douglas Bridge, eight miles 
_ from Strabane; Mullinavarra, three miles from Castlederg ; Derry- 


608 Scientific Proceedings, Royal Dublin Society. 


guinna and Longfield, where most of the stones used in the building 
of Baronscourt were procured; and Drwmquin, west of Omagh. 
In these quarries the stones'are more or less similar to those of 
Cookstown. From the Drumquin quarries were procured the stones 
for the pillars in the Omagh Courthouse. 

At Cookstown, Drumquin, and Carrickmore, especially the latter, 
flagging has been procured for the neighbouring towns. 

Catp.—These rocks occur to the north of the CoaLisLtanp- 
CoALFIELD, and in tracts of less or greater dimensions in the 
county, west and south-west of Dungannon. As pointed out pre- 
viously, they are in some respects similar to the rocks of the 
Slieve-Beagh district. 

Bloom Hill. About four miles north of Dungannon, and three 
from the Donaghmore Station, Great Northern Railway.—Two 
quarries, of different qualities and colour. Creamy, greyish-white, 
and reddish-yellow; the latter, or Red-beds, being inferior. Prin- — 
cipally silicious-grained, very little cement, fine-grained. Some 
beds, especially the reds, are in part argillaceous and micaceous or 
ferriferous. Mr. Hardman states:—“The stone much resembles — 
that at Gortnagluck and Carlan (presently mentioned), is equally 
good for building purposes, and has been much used.”—(G*. S. IL) 
It has been much used in Dublin and other places. In the 
Belfast banks, Donegal and Baliyshannon, it has been found 
very durable. 

Gortnagluck and Carlan. About half a mile apart, and appa- 
rently on one set of strata, about two miles from the Donaghmore 
Station, Great Northern Railway.—Of slightly varied colour and 
quality; creamy, yellowish, greyish, white and reddish—the Red- 
beds being inferior. Silicious-grained ; very little cement; slightly 
micaceous and ferriferous; cuts freely and well; can be raised of 
good scantlings; gets hard from exposure, and is durable when 
worked on its bed. It is a favourite for cut-stone purposes in 
Ballymena, Co. Antrim, where it is considered the best of the 
‘Dungannon stone;”’ the Belfast people, however, seem to prefer 
the Ranfurly (Mullaghana) stone. It was used for all cut-stone 
purposes in Raveagh House, near Fintona; Convent of Mercy, 
Ballyshannon, Co. Donegal ; Roman Catholic Church, Maghera- 
felt, Co. Derry; Harbour Offices, Londonderry; and in various 
other places. 


Kawnanan.—On Irish Arenaceous Rocks. 609 


Spademill. An old quarry, now not of note.-—Some of the 
beds excellent for scythe stones. 

Ranfurly or Mullaghana. Joined by a siding to the Dun- 
gannon Railway Station.—Creamy and yellowish; silicious; very 
little cement; fine-grained; lasting colour; difficult to work. 
The quarry, after being for some time closed, was recently worked, 
but is now (1887) again closed. ‘Was used in the Post Office and 
Northern Bank, Belfast, and Northern Bank, Fintona; also in the 
addition to the Royal University, Dublin, where it has been found 
durable and to retain its colour. 

The “ Dungannon stone,” from some one or other of these diffe- 
rent quarries, has been extensively used in Dungannon. Accord- 
ing to a list, to which I am indebted to Mr. Dickinson, some of the 
principal buildings are: the Provincial Bank, Parish and Roman 
Catholic Churches, Shiel’s Institution, Police Barracks, and Paro- 
chial Hall. Elsewhere it has been used at Roxborough Castle, Moy ; 
bridge over the Ballinderry river, near Coagh (cost £5000); the 
clock tower, and St. Patrick’s Church, Belfast. “These Dungannon 
stones, with those from Dungiven (Co. Londonderry), and Cooks- 
town, were used promiscuously in the public offices (Post-office, Cus- 
toms, and Inland Revenue), and the Apprentice Boys’ Memorial Hall, 
Londonderry ; also with the Dungiven stone only in the Lunatic 
Asylum, where the stones from each quarry were used in a separate 
building. Bloomhill, for the gate-lodge and offices; Gortnagluck, 
for two separate wings; Carlan, in the doctor’s residence; and the 
Dungiven, in two octagonal wings and the front of the old portion 
of the asylum. In the military barracks, Omagh, Dungannon 
stone, of the inferior quality known as the Red-beds, was used ; 
it works easily, but is not durable.’—(J. Cockburn.) 

Aughnacloy.—Greyish to yellowish; silicious-grained. Also 
quarried three miles south-east of Aughnacloy. 

Glencall. One mile from Aughnacloy.—Greyish-white ; slightly 
stained with iron; very silicious; silicious cement; a little mica. 

Brantry. Six miles south of Dungannon.—Purplish-grey ; 
slightly variegated; semi-crystalline; granular; micaceous. 

CoaL-MEASURES.—Some of the arenaceous rocks of this sub- 
group, unlike those that in general occur in the measures of 
Munster and Leinster, are free-working stones. Rarely, however, 
can they be raised profitably, on account of the “clearing” or 


610 Scientific Proceedings, Royal Dublin Society. 


“over-bearing”’ of drift, or useless rocks, that overlie them ; they 
are, however, inferior to the Calp Sandstone, and no quarry in 
them seems now to be worked. 

Edendork. Two miles northward from Dungannon.—Reddish ; 
fine-grained ; slightly micaceous; soft; not now worked. 

Sanp AND GraveL.—Hskers extend from Killymoon, near 
Cookstown, to Dungannon, and thence by Ballygawly, Clogher, 
and Fivemiletown into the county of Fermanagh ; in them there is 
an unlimited supply of good pit sand and gravel. Some of these 
so-called Eskers, as in the Pomeroy valley, are evidently Glacial 
yiwer gravel. (See Monaghan, p. 592.) Good pit sand can also 
be procured near Gortin. River sand occurs in the Foyle, at 
Lifford Bridge, near Strabane ; in the Moyne, near Omagh, and 
elsewhere ; near Castlederg, and in many of the rivers and streams 
from the hills. 


WATERFORD. 


Occupying a considerable area in the east of the county is a 
large tract of Ordovicians. Overlying this, to the west, in the 
Monavullagh and Comeragh Mountains, are massive conglomerates, 
sandstones, and slates, which to me seem to be littoral aceumula- 
tions of the West Cork and Kerry Devonians.* If this suggestion 
is correct, portion of the younger rocks, in the Galtees, to the 
northwest, and Slievenaman to the north, ought to be also Devo- 
nians. ‘These Devonians, as in Cork and Kerry, seem to graduate 
upward without any quick or decided change, into the Yellow 
Sandstone or Lower Carboniferous Sandstone ; as in general the 
dips in both groups of rocks are similiar. ‘This, however, is 

‘not always so, as in the neighbourhood of Glenpatrick, to the 
southward of Clonmel and Kilshelan, there is a sudden change in 
the direction of the dips, the later rocks dipping northward at low 
angles, and the older southward at high ones. This change may 
possibly only be due to a line of fault; but it may be caused by 
an unconformability: it should, however, be more carefully ex- 
amined into. However, to the southward in these hills, and also 


1 John Kelly, I think, was of a similar opinion, but I do not know exactly where 
he stated it. 


Kinanan—QOn Irish Avrenaceous Rocks. 611 


farther west in Knockmeeldown, one group appears to graduate 
into the other; the Yellow Sandstone margining the Devonian. 
The Yellow Sandstones also occur in places eastward (estuary of 
the Suir), and in a band to the northward of the Ordovicians. 

In the south division of the county, that is south of the valley 
from Dungarvan to the Blackwater at Lismore, there are, east and 
west, ridges of sandstones, separated by troughs of Carboniferous 
limestones or shales; and in these ridges, as in Cork, farther west, 
if there is a sufficient thickness of strata exposed, the Yellow Sand- 
stone (Lower Carboniferous Sandstone) is found to graduate down- 
ward into the Devonian. 

In the Bonmahon mining district, in two or three places, very 
small patches of red or purplish conglomerate and sandstone have 
been found lying on, or partly in, the Ordovician. These must be 
either of Silurian or Devonian age, probably the latter: that is, 
small outliers of the Comeragh conglomerates. 

Orpovicran.—The major portion of the grits and sandstones 
are not fitted for general cut-stone purposes, although some dress 
on the bedded surfaces; nor are they in much repute for common 
walling purposes, the associated slate being preferred, except in a 
few cases. There are, however, some green tuffose sandstones that 
are associated with the Exotic bedded rocks; these do not seem to 
have been much utilized in this county, although very similar 
rocks have been used during ancient and modern times, in the 
Co. Wexford, where they have produced good and durable 
work. 

Grange Hill. Waterford.—Here there is a slaty grit that has 
been much used. It is very strong and hard, but very difficult to 
raise, on account of the absence of back joints; it dresses well on 
the face, but not on the edges. It was used in the ancient round 
castle, called Reginald’s Tower, which shows the durability of the 
stone. ‘The dressed work round the opening in this structure is 
of Carboniferous Sandstone, which has weathered much more, but 
evenly, than the Grange Hill stone. 

DeEvonian AND CarBonirERoUS.—In the Co. Cork, the Sidu- 
rians and Devonians are intimately connected, and hard to separate. 
They were, therefore, grouped together. In this county, however, 
it is not the beds below the Devonians but those above them that 
are intimately connected. It therefore is expedient here to group 


SCIEN. PROC. R.D.S.—VOL. V., PT. VII. Ziel 


612 Scientific Proceedings, Royal Dublin Society. 


the Devonians with the Lower Carboniferous Sandstone (Yellow Sand- 
stone), and to describe the stones that occur in both together. 

These stones are very generally used throughout the county, 
either for cut-stone or rubble purposes. The stones usually are 
shades of brown, green, and yellow. In the west of the county 
different varieties of stone are very much mixed up; as quite 
distinct stones very often occur together in one quarry. At 
Skorough, eastward of Lismore, in one quarry, there are four 
varieties, interstratified, ranging from finely-laminated slate to a 
gritty sandstone. A soft, earthy, felspathic, and micaceous stone, 
from Ballysaggart, was used in the dressings of the Roman Catho- 
lic Church, Lismore; while, about three miles eastward of the 
town, in one quarry there are roofing-slates, good flags, and free- 
stone, all of which were formerly worked. ‘These slates, however, 
were eventually cut out by the Welsh slate. In the same town- 
land, but nearer Lismore, there is a stone fit for cut-work ; but it 
varies in quality, the best being in beds from two and a-half to 
three feet thick. ‘There are also other quarries, nearer to the 
town, but difficult of access. For the buildings in Lismore sand- 
stone has principally been used ; but in the church erected about 
fifty years ago limestone was used, and also in the mullions and 
windows of Lismore Castle. 

Glenniveene. About five miles from Lismore.—Flags ; difficult 
to dress, as they are liable to chip at the edges. 

Slieve-Grian. In different places.—Light-coloured, silicious, 
felspathic cement; slightly micaceous; even-grained; porous; 
good quality; works freely. Very generally used for dressed 
work in Dungarvan, from which the quarries are distant some 
seven to nine miles. 

In Cappoquin, the stone most used is a local thin-bedded, 
gritty, silicious, speckled sandstone. 

Oappagh.—An excellent dry stone, but difficult to work, as it has 
no regular bedding or soles. Used in the new house at Cappagh. 
Green flags have also been procured in the neighbouring hills. 

Ballyhavahan and Killongford. Near Dungarvan.—Brownish 
and yellowish, but more usually variegated. Generally soft, fine, 
argillaceous, and micaceous on the bedded surfaces; porous, and 
easily worked. In the quarries there are some subordinate, 
felspathic, and more coarsely-grained. beds, from twelve to fifteen 


Kinanan—On Irish Arenaceous Rocks. 613 


inches thick. Generally used, but often with limestone, for 
rubble and walling in Dungarvan, the dressing being Slieve- 
Grian stone or Whitechurch limestone. 

Ardmore.—The ancient round tower, as pointed out by Wil- 
kinson, “‘is a fine example of cut-stone masonry, and demon- 
strates the durability of the sandstone of the neighbourhood.” 
“Walling in squared coursed work of reddish-grey sandstone, is 
in good preservation.” 

“ Clonmel Quarry.” Half a mile from Clonmel.—Whitish to 
greenish ; silicious; in some beds an argillaceous, silicious cement ; 
works well. The sandstone generally used in Clonmel. 

Millvale. Two miles from Carrick-on-Suir.—Reddish ; silicious ; 
with a little silicious cement; ferriferous. Has been largely used 
in Carrick. 

Waterford.—The conglomerate that lies unconformably on the 
Ordovicians seems to be rarely used, except for road metal. About 
a mile from the town there is a quarry in reddish-brown, good 
sandstone; but as it is difficult of access, it is not now much used. 

Brown Head Promontory. Wast of Tramore Bay.—Dark-red 
sandstone. It is very effective, with granite mouldings, in New- 
town House, near Waterford. 

To the east of the county, adjoining the estuary of the Suir 
and Barrow, there are limited tracts of conglomerate and sand- 
stone well adapted for heavy work, such as piers and sea-walls, 
as they are capable of being raised in large squarish blocks. At 
Dunmore Hast there are good workable beds in the red sandstone 
cliffs, which have been locally used in sea-works; in the town 
and the coastguard-station : they are not durable. New Ross pier, 
Co. Wexford, is built of this class of stone; which was brought. 
either from one of these tracts, or from that at Ballyhack and 
Arthurstown, Co. Wexford. Mr. Langrish states :—‘ The stone, 
from its hardness and roughness of surface, ought to make splen- 
did coping for a quay wall, preferable to granite or limestone, 
which wear quite smooth.” 

SAND AND GRAVEL.—Pit sand and gravel are dispersed over the 
county, but generally not in quantity. In many cases the sand is 
very fine. At the round hill near Lismore there are good building 
and moulding sands, the latter used in the Cappoquin Foundry; also 
close to Ballyduff railway station. River sand is found in some of 

2T2 


614 Scientific Proceedings, Royal Dublin Society. 


the rivers and streams. For Waterford, they procure it about 
sixteen miles up the Suir, near Portlaw. “At Bonmahon there is 
a sea sand (AXolian) fit for almost any building or concrete. It is 
artificial, being due to the washings from the stamps when the 
copper mines were at work.”—(W. S. Duffén). 

Guass.—LHarly in the century glass bottles were made opposite 
to Ballycarvel; and subsequently, about fifty years ago, there was 
a large glass manufactory. The “ Gatchell or Waterford glass” 
was famous, this “ Irish glass”” having a name even in India, to 
which it was largely exported. It ceased about 1845, after the 
death of George Gatchell, as on his death the lease of the premises 
expired, and the landlord wanted to double the rent. This, com- 
bined with his widow wishing to retire to Hngland—her native 
country—broke up the industry. <A sand for cutting purposes 
is said to have been brought from the Co. Kilkenny, and the rest 
from the Isle of Wight, England. 


[Flint sand is the principal ingredient in flint glass. There is also red-lead, pearl- 
ash, manganese, arsenic, &c., the ingredients and the quantity of each used depending 
on the METAL-MIxER. The metal-mixer locks himself into his room, and there mingles 
the several compounds. If his talent in this department leads to a good result, as was 
always the case in the Waterford glass when Walter Purcill was the metal-mixer, 
such a man can almost carry everything his own way.—(George Miller).] 


WESTMEATH. 


This area is occupied nearly solely by Carboniferous limestone. 
At Sion Hill, however, north of Killucan, there is a very small 
exposure of Ordovician, margined by Lower Carboniferous Sand- 
stone, the latter rock also appearing in a few scattered exposures 
near Moate, and near Ballynacarrig, to the north-west of the 
county. ‘These sandstones are of very limited extent, and are 
only used in their intermediate vicinities. 

South-west of Mullingar, in the parish of Lynn, are some 
quarries of calcareo-argillaco-arenaceous flags. 

Sanp anp Graven.—Pit sand and gravel are common through- 
out the county, and of a fair quality. 


Kanan an—On Irish Arenaceous Rocks. HES) = 


WEXFORD. 


Under the major portion are Cambrian, Ordovician, and Granite ; 
Carboniferous rocks only occurring in very limited tracts, as near 
Wexford Harbour, in a band across the baronies of Forth and 
Bargy, at Baginbun, in Hook Promontory, and on the edge of 
the estuary of the Suir, westward of Fethard, and at Bally- 
hack. 

CamBrian.—These rocks are in part metamorphosed. Some of 
the more hornblendic patches have been said to be of Laurentian 
age; as, however, such patches would be Mosaics in the Cambrians 
(to quote Dr. Callaway), it is far more probable that all are equiva- 
lents of the Cambrian (page 516). In these there are quartz-rock, 
quartzyte, and grits, mostly unshapely, and more suited for road 
metal than any other purpose. Some of them, however, can be 
raised in large blocks, suitable for sea-walls, for which they have in 
places been used, as in the embankments of the north and south 
intakes. 

Orpovicran.— Usually the grits are only suitable for rough 
local walling ; in places, however, there are more or less calcareous 
tuffose sandstones associated with the interbedded Exotic rocks. 
These, as exhibited in the ancient structures, such as the old build- 
ings in Ferns and Wexford, if well selected, are durable stones ; 
and are also capable of fine sculpturing, as seen in the beautiful 
Egyptian doorway of the little church of Clone, about a mile 
southward of Ferns. Of late years they have been used in Clone 
new church, and in some of the bridges of the Dublin and Wex- 
ford Railway. It is a stone that ought to be more generally used, 
being very free-working, easily raised, and durable if well selected. 
When first worked, the colour is greenish-grey; it then becomes 
discoloured, but this discolouring seems subsequently to wash out, 
if we may judge of the stones as they now appear in the old build- 
ings. If, as in the States of America, sawing was introduced into 
our quarries, this would be an admirable stone to be thus worked, 
as it is light and porous, and might be cut into sizes from the 
scantling of brick to those of quoins, sills, &c. It seems capable 
of heavy and long bearings. 

Ballymore, near Gorey.—A sandstone quarry ; but it is jointy, 


616 Scientific Proceedings, Royal Dublin Society. 


and does not work well; Bagnalstown granite was preferred to 
it for the dressing of Kilternel Church, Courtown. 

CarBonirERous.— Lower Carboniferous Sandstones are yellowish 
and reddish shaly sandstones, and more or less coarse conglome- 
rates. In the neighbourhood of Wexford Harbour they have 
been quarried, principally near Castlebridge, at Artramon, at 
Saunder’s Court, and at Park. From the latter were procured 
the stones for the ‘‘ Father Roche’s Churches” in Wexford. It is 
a pebbly sandstone or fine conglomerate, and gives a picturesque 
and unique aspect to the buildings. As pointed out by Wilkinson, 
it is a peculiar stone, and must be urderstood by the masons, as 
under ordinary circumstances it would be rejected, and an inferior 
stone preferred. If, however, it is dressed immediately on being 
raised it works well, and makes sound, durable, and dry work. 
It was in part used in the old abbey at Wexford. As it can be 
raised in squarish blocks, it is also very suitable for quay walls, 
and such like large work. 

A more or less similar stone, and a yellowish sandstone has 
been quarried in places in the baronies of Forth and Burgy, 
especially near Duncormick. 

At Baginbun, in the Hook Promontory, south of Duncannon, 
and at Baillyhack, there are massive conglomerates and sandstones 
that can be raised in large blocks suitable for piers and such like, 
having been used, among other places, in the pier at Kilmore. 
Near Arthurstown are quarries of good grits, formerly much used 
for millstones. (See Waterford.) 


[In most of the old ecclesiastical buildings in this county, a stone very similar to 
the caenstone has been largely used. Some caen may have been used; but, as pointed 
out by Mr. Robertson of Kilkenny, the stone is probably Teas stone, from near 
Glastonbury, England. (See Kilkenny.) ] 


Sanp anp Gravet.—In this county, below the 250-feet con- 
ture level in places, there are vast accumulations of manure gravel, 
a shelly sand, formerly much used for bedding cattle, and after- 
wards as manure. This, to the northward near Gorey, and be- 
tween Enniscorthy and Newtownbarry, graduates into ordinary 
sands and gravels, those in the Slaney valley being for the 
greater part limestone. There are also, for miles along the coast- 
line, large tracts of Afolian sand; this, also, in places was formerly 


Kinanan—On Irish Arenaceous Rocks. 617 


used as manure on the “ marl land,” being considered most bene- 
ficial if brought from below high-water mark “with the sea in 
it:” that is, when wet and salty, it was considered better than 
if the salt was worked out of it. 

Tn the Gorey district, and the upper portion of the Slaney valley, 
there is good pit sand and gravel, also at the Deeps, to the north- 
ward of Wexford, and in some other places. Good river sand can 
be procured in limited portions of the Slaney, and the other rivers 
and streams. 


WICKLOW. 


In this county sandstones or allied rocks that are now in favour 
for cut-stone purposes are few. The area is solely occupied by 
Granite, Cambrian, and Ordovician, the latter in a great measure 
metamorphosed. 

In the Camprian at Bray Head, and also in the hills north- 
east of Togher or Roundwood, there are extremely hard green grits, 
and, in other places, the quartz rocks are well suited for road- 
metal; but some of the more regularly-bedded and granular 
varieties of the quartzytes might possibly be worked. 

Glencormick. North of the Great Sugarloaf.—Warm cream 
colour; fine-grained; silicious, thin-bedded; cuts easily and well. 
Extensively used in Bray and other places in that neighbour- 
hood.—(7. B. Grierson.) 

In the less altered OrpoviciaNns, near the west margin of the 
county, are interbedded green tuffose sandstones, allied to those 
described in the Co. Wexford. Some of them were used in the 
old structures, and gave good, durable work. At the Seven 
Churches, Glendalough, in the building now called “St. Kevin’s 
Kitchen,” a metamorphosed stone, apparently of this class, was 
cut to the slope of the stone roof, besides being worked in other 
ways, as in a carving over the doorway of the structure now called 
“The Library.” 

Sanp anp GraveL.—FPit sand and gravel occurs in places in 
nearly all the valleys; and from the washing of them by the 
streams, good river sands are produced. 

For long distances along the seaboard are greater or less 
accumulations of Holian Sand. At Arklow, the fine sand drifted 


618 Scientific Proceedings, Royal Dublin Society. 


through the rampart at the Chemical Works is sent to Dublin to 
be used in the sawing of blocks of stone and for polishing. ‘This, 
as mentioned in the “ Introduction” (page 529), suggests a new 
industry. 

Guass.—At Melitia, westward of Shillelagh, and about two 
miles from the ancient church of Aughowle, there is the site of an 
ancient glass-house, to which attention has recently been directed 
by the Rev. J. F. M. Ffrench (Jour. Roy. Hist. Arch. Ass., Ire., 
vol. vii., 4th ser., p. 420). In the neighbourhood there is a sand 
which the glass-workers of Dublin state, “if ground down, it 
ought to be a suitable sand.’’ Glass seems also to have been 
manufactured at the Chamney Iron Furnace, Shillelagh, as some 
years ago, when removing part of the old ruins, a quantity of glass 
slag was found. 

In the townland of Ballymanus, westward of Aughrim railway 
station, there is a dyke of fine white sand, evidently a decomposed 
felsitic rock. This has been submitted to the glassmakers at 
Ringsend, Co. Dublin, who state it is too clayey for clear glass, 
but ought to be excellent for black glass. To meet the Dublin. 
market it would have to be delivered at about 3s. per ton. 


Kinauan—On Irish Arenaceous Rocks. 619 


NOTES ADDED IN THE PRESS. 


CO. DONEGAL. 


Dunmore Head ; and Croagh—Innishowen—one and a-half miles 
south-west of Dunmore Quay, and two and a-half miles south- 
west of Culduff. Bluish-grey quartzose flags can be raised in 
squares from 6 to 10 feet, and of all thicknesses, some thin 
enough to be used as roofing-slates.—(A. I/‘Henry). 

Kindrum — Fanad-within-the-Waters — west of Kindrum 
Lough.—Veins of thin, micaceous silicious flags can be raised 
in large sizes, capable of long bearings; mottled whitish-yellow, 
or pinkish colour. This stone appears capable of being sawn, 
and ought to be effective if used in fancy tiling. 

Shanaghan—Axrdara—near Shanaghan Lough, and other places 
in Loughros Promontory.—Vein of micaceous-silicious flags, from 
two inches or more to the thickness of roofing-slates, for which 
purpose they have been used; can be raised of considerable sizes, 
capable of long bearings. 

Slieveleague—Carrick. Silicious flags. 


CO. DUBLIN. 


Ringsend glass.—For black, Irishtown sand ; for clear, Antwerp 
sand; about 9s. per ton; or “Granuloid”’ (Portsmouth). The 
latter is a finely-granular quartz rock; it is supplied in blocks, 
costing about £1 per ton. 

The following are the ingredients used in the manufacture of 
black and clear glass, respectively :— 


Black Glass. Clear Glass. 

Trishtown sand. Antwerp sand. 
Waste lime (after manufacture of Whiting (Glenarm). 

mineral waters). Soda ash. 
Blue clay. Red lead. 
Broken tiles. Manganese. 
Kelp waste (substitute for soda 

ash). 
Rocksalt. 


Fluorspar. 


620 Scientific Proceedings, Royal Dublin Society. 


To make twenty gross of mineral water, or fifteen gross of 
brandy bottles, which is the quantity usually run from a fur- 
nace :— 

18 cwt. Antwerp sand. 
4 ,, chalk (or whiting). 
De usodaragh: 
2  ,, sulphate of soda. 
4 lbs. red lead. 
24 | py RES ATUG. 
2 ,, manganese. 
About 1 ton of waste glass, such as broken window-glass. 


The “ Granuloid,’’? when used, is thrown in, in the block, which 
rapidly melts down. 

A rock very similar in aspect to the “Granuloid” occurs in 
the Howth Promontory, also in places in the counties Wicklow, 
Wexford, and elsewhere in Iveland.—(R. Clarke.) 


[ 621 j 


LI.—ON A SEPARATING APPARATUS FOR USE WITH 
HEAVY FLUIDS. By PROFESSOR SOLLAS, LL.D. 
(Plate XIII., Fig. 1.) 


[ Read, January 19, 1887.] 


Awoncsr the difficulties presented by the method of separating the 
mineral constituents of rocks with the aid of heavy fluids are two 
which the apparatus to be described fully overcomes. These are: 
first, that of removing the separated mineral from the apparatus ; 
and next, that of effecting a rapid mixture of the fluid already in 
the tubes, and that which is added to reduce its density. The first 
is readily met, by using two tubes, which are united by a joint, with 
ground surfaces (fig. 1,a); the second, by closing the tubes with a 
stopcock at each end (s, s’), so that after each addition of dilute fluid 
the apparatus may be inverted. In using this apparatus, the heavy 
fluid having been introduced, the powdered mineral is added and 
allowed to separate. When the separation is complete, the stop- 
cocks are all closed, and the two tubes separated from each other. 
If any mineral remains above the stopcock (s”) it may be washed 
into the upper tube ; the lower tube is then supported over a funnel 
containing a filter paper, and the contents allowed to run out by 
opening both stopcocks (s’, s”). If any particles of the mineral 
remain behind adherent to the sides of the tube, they may be 
washed out by water. The tubes are then fitted together again, 
the stopcocks opened, and diluted fluid or water added; the ter- 
minal stopcocks at each end are then closed, and the tubes turned 
one and the other way up till perfect admixture is obtained; the 
whole is then left to settle till another separation is accomplished. 
To furnish the experimenter with approximate information as to 
the specific gravity of the liquid in the tubes, and to enable him to 
obtain approximately a desired specific gravity, the tubes are gra- 
duated so that the specific gravity of the fluid used at starting being 
known, and its volume also a measured volume of the diluent of 
known specific gravity can be added. 

It may be useful if I here add a short account of the course of 
mechanical separation and associated operations, as carried out in 


622 Scientific Proceedings, Royal Dublin Society. 


the Petrological Laboratory in Trinity College. ‘The rock under 
examination is powdered till it all passes through the finest sieve 
usually to be found in a chemical laboratory; sufficient is taken 
from this for all purposes of chemical analysis; the remainder is 
placed in a tall beaker and washed with water. In this manner 
the fine dust or flour is removed, and one obtains a larger quantity 
of material, in relation to the quantity of rock pulverized, than if 
one employed only the powder, which will not pass through the 
finest sieve, with the additional advantage that it is of finer grain, 
and thus affords purer separations. No loss of time is involved in 
the use of finer powder; indeed, from the more perfect separation 
which it insures, there follows a slight gain in this direction. The 
fine powder is then dried in the water-oven and introduced into the 
separating-tube; the powder, first separated, is well washed with 
distilled water and dried, and its specific gravity taken by the aid 
of the modified Sprengel’s tube, described in the succeeding Paper 
The powder, after removal from the Sprengel, is washed first with 
ether, and then with absolute alcohol, dried, and, if necessary, 
analysed; a known volume of water is then added to the mixture 
which remains in the separating-tube till another mineral com- — 
mences to fall, and the course of procedure just described is re- 
peated. From the quantity of water added a good idea, useful 
as a guide, is obtained as to the specific gravity of the fallen 
powder, and, in some cases, this will be sufficiently near the 
truth to render a more exact determination needless. 

From experience I can recommend this course of procedure both 
for speed and accuracy. 


TL ee 


LITI.—ON A MODIFICATION OF SPRENGEL’S APPARATUS 
FOR DETERMINING THE SPECIFIC GRAVITY OF 
SOLIDS. By PROF. SOLLAS, LL.D. (Plate XIII., 
Figs. 2-7.) 


[Read, February 16, 1887. ] 


Tue simple and elegant specific gravity tube of Sprengel is not so 
well known among mineralogists as to render its description as 
a preliminary to indicating a slight modification of it unnecessary. 
Tt consists (fig. 2) of a small U-tube, drawn out at each end into a 
capillary. The capillary tubes are bent outwards, at right-angles 
to the limbs of the U-tube, and one of them grows wider (fig. 2, e), 
and the other narrower (fig. 2, a), as it recedes from the limb of 
the tube, with which it is continuous. A mark (m) for reference 
is etched at any point chosen on that capillary which expands 
outwards. This apparatus affords us a means of obtaining a 
definite volume of any fluid with an ease and accuracy which is 
not approached by any other direct method. The method of 
working is as follows:—The distally converging capillary (a) is 
immersed in the fluid with which it is desired to fill the apparatus, 
and by sucking at the end of the other capillary, the fluid naturally 
flows in. When it is filled beyond the mark on the expanding 
capillary, excess of fluid is drawn off by applying a piece of blotting- 
paper to the end of the converging capillary, the meniscus in the 
expanding capillary then slowly travels inwards, and when it 
reaches the fixed mark the volume of the fiuid is defined. 

So far this apparatus has only been used in the case of fluid 
bodies; and even were it not possible to extend its application to 
solids, it might fairly be regarded as almost indispensable to the 
mineralogist for determining the densities of the heavy fluids used 
in the separation of the mineral constituents of rocks; but by a 
very simple modification it can be adapted to determine the 
densities of these minerals themselves when in a state of powder, 
as they necessarily always are when obtained separate by the use 
of heavy fluids. ‘This modification consists in directing the distally 
expanding capillary vertically upwards, and enlarging it at its 


624 Scientific Proceedings, Royal Dublin Society. 


termination into a funnel of a little larger diameter, at the brim, 
than that of the limbs of the U-tube (fig. 3). 

The apparatus is first filled with water up to the fixed mark, 
and weighed; this weighing, after deduction of that of the tube 
itself, gives the weight of the volume of water required to fill the 
tube as defined by the mark. If it were possible to introduce now 
a weighed quantity of the powdered mineral, the density of which 
it is desired to ascertain, we should then simply have to draw off 
the excess of water till the fixed mark were reached, and the next 
weighing would give the weight of the water displaced by the 
mineral, and from this the specific gravity could be obtained at 
once. 

This, indeed, is the principle employed; but the details 
are slightly modified. The surface-tension of water is so great 
that the powdered mineral, although well cleaned by the action 
upon it of the mercury and potassium iodide used in its 
separation, will not all sink through, but a small portion 
always floats as scum on the surface; it is therefore necessary to 
substitute some other fluid for water, and that which I have found 
succeed as well as any is the common paraffin used for burning in 
lamps. The specific gravity of this having been ascertained by 
means of the tube, the latter is filled with paraffin up to the brim of 
the funnel, and the powdered mineral introduced from a small 
weighing bottle. It rapidly falls through the paraffin, not a grain 
remaining on the surface. ‘There is no difficulty in completely 
filling the limb of the tube from which the funnel proceeds, and 
thus results of accuracy can be obtained ata minimum expenditure 
of time and trouble. It may be useful to add a few suggestions 
on the filling and emptying of the apparatus. In filling, the tube 
should first be inverted (fig. 4), and care should be taken that the 
end of the immersed capillary does not accidentally emerge from 
the fluid. By sucking at the funnel end the liquid readily enters. 
When one limb has been completely filled up to the narrow con- 
striction by which it is joined to the other the apparatus should be 
restored to the upright position (fig. 5), care being still exercised 
that the immersed capillary does not leave the fluid. The empty 
limb now fills by outflow from the full one, which is supplied 
by the siphoning action that takes place, now that it is in an 
upright position. By this method of filling air bubbles are 


Sortas—On a Modification of Sprengel’s Apparatus. 625 


avoided, and the chance of the liquid (which may be corrosive or 
otherwise objectionable) entering the mouth is precluded. In 
emptying, when powdered mineral is present, the apparatus should 
be inverted in a small beaker of paraffin, and slightly inclined, so 
that none of the powder may find its way into the second limb. 
When all the powder is removed (and it falls out very rapidly), the 
paraftin is drained out, and the tube washed, first with ether, and 
finally with absolute alcohol. 

The apparatus has the advantage of being very easily con- 
structed. <A piece of soft glass tube of convenient length, and any 
diameter, not too small nor too large (the operator can use his own 
judgment, within somewhat wide limits), is softened at one end, 
and enlarged into a funnel-shape (fig. 6), with a piece of hard, 
conically-pointed charcoal. A glass thread is then fused on to the 
edge of this, to enable the operator to draw out the narrow neck. 
This done, the other end is then drawn out into a capillary (fig. 7). 
The middle of the tube is next softened in a somewhat small blow- 
pipe flame, drawn out, and at once bent, till the two halves of the 
tube are brought into parallelism. The terminal capillary is then 
bent into a position at right angles to the tube from which it pro- 
ceeds, by holding a lighted lucifer-match under it, and allowing it 
to bend under its own weight. The two limbs of the tube should 
be sufficiently far apart to allow of their being cleaned on all 
sides. 


[ 626 ] 


LIV:—ANALYSIS OF THE BERYLS OF GLENCULLEN, CO. 
WICKLOW. By W. N. HARTLEY, F.R.S., Royal College: 
of Science, Dublin. 


[Read, March 23, 1887]. 


Tue beryls of Glencullen, Co. Dublin, described by Professor 
J. P. O’Reilly,! and by Mr. J. Joly, B.H.,? were analysed about 
twelve months since by Mr. J. B. Wise, a student in the Royal 
College of Science. 

Analysis.—One grain of the mineral was fused with six parts 
of mixed potassium and sodium carbonates. After treatment with 
_acids, it was found that a small portion of the substance remained 
unattacked. This was again fused, and it then showed a very 
decided green colour characteristic of manganese, possibly derived 
from the iolite contained in the mineral. The following are the 
data :— 


Anatysis I. Awnatysis IT. 
Ordinary Crystals. ‘‘ Weathered’’ Crystals. 
Per Cent. Per Cent. 
LOR are sane Mie MR GAae 54:27 
ISOS Sd ge teh OO FLO, 27°23 
Bein: eigenen Gessye  (LAS29 10°50 
CaO se eae eg 2260) 1°40 
ME ON eae OS 2°88 
McQ) eerie perianal Ose 0°47 
IN ak OG anes eweseuire LarOs4G. 0°47 
HG OW ae eucimuck nce) oe oOo, 0°41 
MnO trace. 
TO ae Mahe cc tee OES Not estimated. 
98°95 97°63 
Bases = 51:01 Bases = 48°36 
Silica = 47°47 Silica = 54:27 


The specific gravity of the speocus represented by Analysis I. 
is 2°706 at 15:2°C. 


1 Proceedings, R.D.S., vol. iv., p. 505. 
2 Proceedings, R.D.S., antea, p. 48. 


HartLty—On the Beryls of Glencullen, Co. Wicklow. 627 


It will be observed that the weathered beryl contains what one 
might expect—a diminished proportion of bases and a correspond- 
ingly increased proportion of silica. According to the very careful 
research of C. A. Joy “On Glucinum and its Compounds,” fusion 
of beryls with two parts of potassium carbonate can be successfully 
carried out.’ 

Fresenius states, “‘ Native silicates of beryllia are completely 
decomposed by fusing with four parts of carbonate of soda and 
potassa.”?? 

The proportion of alkaline carbonates necessary for the fusion 
of Glencullen beryls was found to be not less than six parts. 

On referring to the composition of the beryls of Acworth, New 
Hampshire, which were the subject of Joy’s research, it is to be 
noted that they contain more silica by one-third, and only one- 
half the quantity of alumina contained in the Glencullen beryls, 
thus :— 

Composition of New Hampshire Beryls. 


S10, 68°84, Al,O; 16°47, BeO 13-40 Fe,O; 1:7. 


Those who are acquainted with the difference in behaviour of 
silicious minerals, when treated with alkaline carbonates, will 
acquiesce in the opinion that it is this high percentage of alumina 
which renders the beryls of Glencullen so difficult of fusion. 

Taking into account the small proportion of bases present 
which are capable of replacing BeO, such as 2°6 per cent. CaO, 
313 per cent. FeO, and calculating the molecular proportions 
of the other constituents, I have assigned to the mineral the 
following formula :— 


2 (A1,0;°3Si0,)-2 (Be,Si0,)-BeO-Al,0; ; 


or, differently expressed :— 
2 (Al,8i;09)-2 (Be,S810,) -BeA1,O,. 


From the point of view of their chemical composition these crys- 
tals are not beryls, but apparently a new mineral with a constitu- 
tion lying between beryl and chrysoberyl, that is to say between 
a silicate of alumina and beryllia and an aluminate of beryllia. 


1 American Journal of Science, vol. xxxvi., p. 83. 
2 Qualitative Analysis. Ninth English Edition, 1876, p. 103. 
SCIEN. PROC. R.D.S.—VOL. YV., PT. VII. } 2U 


628 Scientific Proceedings, Royal Dublin Society. 


Its mode of crystallization is unusual, being almost invariably 
radiated, though the erystals are hexagonal prisms. 

In Mr. Joly’s Paper it is shown that through some of the beryl 
crystals there were veins of felspar, and that near the base of a 
hexagonal prism there was an admixture of orthoclase and beryl. 
We may arrive at an approximation of the quantity of orthoclase 
admixed with the beryls which were the subject of the foregoing 
analyses, by taking into account the alkalies present, and assuming 
that they were not a part of the beryl, but constituents of the 
orthoclase; and, further, by taking into account the alumina pre- 
sent in beryls and in orthoclase. 

Out of seventy-eight analyses of different specimens of ortho- 
clase, the following numbers were taken as representing its average 
composition :— 


S10, 65 per cent. Al,0; 19 per cent. Alkalies, 14 per cent. 


The alkalies in beryl are 1:08 per cent., corresponding to a 
maximum of orthoclase of 7-7 per cent. While the alumina in the 
Glencullen beryls is 82:5 per cent., that in twenty other specimens 
is 18 per cent., or the same proportion as that in orthoclase. ‘The 
difference in the proportion of silica in orthoclase and beryls is not 
great; in the latter mineral it amounts to 67 per cent., or 2 per — 
cent. more than in orthoclase. 

After the elimination of such quantities of bases and silica as 
may constitute an admixture of other minerals, we have to account 
for the presence of only 47°47 per cent. of silica, and the large pro- 
portion of 32°49 per cent. of alumina, that is to say, a deficiency of 
21 per cent. of the former, and an excess of 16 per cent. of the 
latter; and the only way in which this can be done is by assign- 
ing to the beryls of Glencullen a formula which represents their 
constitution in the manner already described. 


TS 


i 629° | 


LY.—DEAL TIMBER IN THE LAKE BASINS AND PEAT BOGS 
OF NORTH-EAST DONEGAL. By G. H. KINAHAN, 
M.R.LA. 


[Read, April 20, 1887.] 


ArTENTION to the ‘“corkers,’’ or roots of trees, apparently in their 
natural positions in some of the lake basins, Co. Sligo, was directed 
by Mr. A. B. Wynne, at the last meeting of the Society, and he 
suggested that it was possible that once they may have been on a 
higher level on a substratum of peat, the latter being gradually 
removed by the wash or suction of the lake water, so that even- 
tually they sank to their present position (antea, p. 499). 

In the north-east of the barony of Kilmacrennan, Co. Donegal, 
“‘corkers” in the basins of the loughs and loughauns are very 
general; and for the last two years I have made them a special 
study, as it appears difficult to conceive how trees such as oaks and 
firs, especially the latter, which most abound, could have grown in 
places from which there is now no natural drainage. 

In this portion of Donegal these loughs and loughauns are in 
more or less regular bowl, or saucer-like, depressions; while in 
some places there are shallow, oval, dish-shaped depressions, occu- 
pied by bog, in all of which deal or oak corkers are found in situ, 
that is, where they originally grew, below the present level of the 
natural drainage. Since the paper mentioned was read I have had 
opportunities of carefully noting the facts in connexion with some 
of the bogs and lakes which are now recorded. 

No. I. Bog in the Depression about Lough Aweel, between 
Ramelton and Milford.—This lies in a large, irregular, oval, 
dish-shaped depression. To drain the bog, and make it available 
for turf-cutting, canals have been opened to the southward and 
westward, through the rim of drift margining the hollow; and at 
the greatest depth the bog has at present been cut, in the sub- 
stratum, corkers of oak occur; while a little above these, in the 
peat, and extending horizontally to and on to the marginal drift 
rim, are corkers of deal. None of them seem to have been dis- 
placed, after they originally grew, until the bogs were cut. 

No. II. Glencarn Bog, or Mili-pond.—This is situated a little 


SCIEN. PROC. R.D.S.—VOL. V., PT. VIII. 2X 


630 Scientific Proceedings, Royal Dublin Society. 


north-east of Ramelton, by the new road to Glenalla. At one 
time it was a boggy lake, and a bank seems to have been built 
across its embouchure, to utilize it as a mill-pond. Subsequently the 

peat in it was cut, and its level lowered by a canal. Now, the cut 
from the site of the old lake has been made so deep, that the tract, 
at will, can be entirely drained, so that it is a mill-pond in winter 
and a peat bog in summer, according as the sluice is down or up. 

When the waters are out it can be seen that some of the deal 
corkers in the area are in the position in which they originally 
grew, while others were evidently originally at a higher level in 
the peat, and were dropped down by the peat being cut away from 
under them. ‘There are others also in a sedimentary peat; and 
although they look as if in their original natural positions, which 
some of the turf-cutters say they are, yet it seems to me quite 

possible that they may be “dropped corkers,” around which 

recent sedimentary peat, the washing from the turf-banks and 
holes, may have accumulated. 

Nos. III. and IV. Carn and Thorn Lakes.—These lie north 
of Glencarn Bog, in the vicinity of the road. In both, especially 
the latter, there are numerous deal corkers, most, if not all, of 
which are in their original positions. In connexion with these 
lake basins, it is possible that the drainage from them was stopped 
by the accumulation of peaty matter. 

No. V. Pollet Lough, between Doagh Bog and Fanad Light- 
house, in the north-east portion of Fanad.—This loughaun is 
situated in a shallow, bowl-shaped depression. Numerous deal 
corkers, the majority evidently in situ. No apparent old site of a 
drainage vent. 

No. VI. Kindrum Lake. In Fanad-within-the-Waters.—In 

‘the south-west arm of the lake is a cut-away bog, with deal 
corkers in situ. The stream from the lake is now a mill-race, the 
water of the lake being lowered in summer to allow the peat to be 
cut. The mill-race is cut in a stony drift, that never could have 
been brought into its present position by the lake waters. 

No. VIL. Tawney Lough, near the village—Numerous corkers 
in a saucer-shaped depression. ‘They are evidently in their 
natural positions; while there are. others that show the marks of 
the turf-cutters. The present drainage of the lake is a deep cut 
through the drift rim. 


Kinanan—Deal Timber in the Lake Basins of Donegal. 681 


The selected lakes and bogs enumerated are sufficient to illus- 
trate the general position of the corkers, and the situation in 
which they occur. From these examples it is evident that the 
majority are still in their natural positions. The general history 
of these different basins seems to be: as the turf was required, the 
canal from each lake basin was deeper; but when all the turf 
was cut the canals were neglected, and the sides caved in. This 
stopped the drainage, forming lakes on the sites of the old cut- 
away bogs. ‘This in a measure may suggest how the drainage in 
old times was stopped; but at the same time it is not satisfactory, 
as it may be asked : by whom, or how, were cuts made through the 
margins of the hollows ? 

In connection with this subject the bogs margining the river 
Shannon may be referred to. Those above the rock barrier at 
Castleconnell (Falls of Donass) are in places lower than the sill of 
the Falls; but as I have in previous writings suggested, the drain- 
age from the present basin of these bogs may have been south-west 
into the plain of Limerick, and thus independent of the Donass 
Falls. But in connection with the basin of Lough Derg, there are 
oak and deal corkers in situ in the bogs adjoining, far below the 
present level of the lake. This level I have also accounted for in 
a Paper “On the Basin of Lough Derg,” as the drainage might 
have been southward into the Pollagh and Kilmastulla valley. 

But when we go above Portumna there are hard questions, 
as the bogs along that section of the river and the Little Brosna 
are of great depth; and wherever they have been bottomed, oak 
corkers in sitw have been found. How the land on which these 
grew could have had a surface drainage, eastward of the sill of lime- 
stone near Portland, it is hard to conjecture. 

From the examples given it is quite evident that the majority 
of the corkers are now in their original position, and that the 
question of most importance is: How were these depressions 
drained to allow trees of deal and oak to grow there in former 
times ? 

Years ago I suggested that in places the flooding of hollows 
might be due to “beaver dams,” but at the same time I pointed 
out that in the Irish glossaries there was no name for a beaver, the 
word in O’Reilly’s Dictionary being taken from the Gallic. Since 


then, from a personal knowledge of beaver workings, I cannot say 
2K 2 


632 Scientific Proceedings, Royal Dublin Society. 


that I see anything specially like them in Donegal, although some 
of the flats elsewhere may possibly have once been “beaver 
meadows.” Under any circumstances, none of the cases in the 
county Donegal above enumerated could be due to such a cause. 

From the places in which timber grew, and other circumstances, 
it is evident that before the advent of the bogs, Donegal must at 
one time have had a climate very similar to that now existing in 
the neighbourhood of the Gulf of St. Lawrence, Canada; and in 
connection with such a climate there must have been snow and ice, 
and during the thaws great slides of drift, which may have dammed 
up the lakes, as is the case in the present day in the province of 
Quebec and elsewhere in the Dominions. Some such solution 
might be suggested for the roots (corkers) of deal and oak being 
now found in sitw in places from which, since the bogs began to 
grow till the present time, there has been no natural outlet for 
the drainage. 

In connection with this subject the peculiarities of the timber 
found in Cloncarn bog, north of Treantagh, may be recorded. In 
Donegal, as seems to be usual elsewhere in the province of Ulster, 
the bogs are not at once cut to their full depth, but are “ gone- 
over” in breasts of banks about three or four feet deep; so that in 
accordance with the depth of the peat accumulation the bog may 
be “ gone-over”’ two, three, or more times before the final cutting 
that bottoms the bog. The upper cuttings or “ gone-overs”’ of the 
Cloncarn bog are things of the past; but now they are bottoming 
out the bog, and the last cutting has given an appearance to it, 
similar to a bush-clearing in Canada—each tree stem standing 
three or four feet high. In Canada and the States, when clearing 
the bush, they cut off the tree between three and four feet fromthe — 
‘ground, as a man can cut more trees in a day if he stands upright 
than if he stoops; while subsequently, after the land is tilled, it is 
easier to remove the roots, if they have a stem to act as a lever, 
than if they are cut close to the root. It can scarcely be supposed 
that the trees in the Cloncarn bog were similarly treated to those 
in a Canadian bush-clearing, as it seems evident that their present 
height is due to the floor of the last cutting-over of the bog, all 
sticks over that floor having been cut off. But even allowing this, 
they are peculiar as in general timber, that is, “bog stick,” are 
found broken off and lying horizontal—the breaking off usually 


Kryanan—Deal Timber in the Lake Basins of Donegal. 633 


being close to the corker, and rarely a few feet above it. This is 
the case, as far as my experience goes, not only elsewhere in 
Ireland, but also elsewhere in the county of Donegal, the trees 
having fallen before the bog grew, while here the bog must have 
grown around the standing trees. Furthermore, these trees must 
have been higher than as now represented, as it is possible they may 
have protruded, not only into the “going-over”’ before the last, 
but into higher strata; their original perpendicular height, how- 
ever, cannot now be recorded, as all the cuttings of the bog but the 
last “ going-over” was in the time of the ancestors of the present 
generation. — 

Besides this uncommon phenomenon, that is, peat banking up 
standing timber, there is another peculiarity to which I may refer— 
the spiral growth of many of the trees. This, however, is not 
confined to the timber in this bog, as I have remarked it in the county 
Donegal and elsewhere in Ireland. This I first remarked in the 
Cypress in Ontario, and it seems to be due to the hot suns in the 
Spring causing the bark on the south side of the stems to grow 
much quicker than on the cold north side; the trees that germi- 
nate early being thus affected, while the later ones are not. In 
these ancient Irish forests the same thing seems to have taken place, 
as in places many of the trees grew spiral, while adjoining ones 
grew straight. I do not know enough to be able to state if the 
timber which grows spiral is of a different species to that which 
has grown straight, but I would point out that in the bog of Kil- 
pheak, north-west of Fox Hall, a large stick 20 yards long, 3 feet 
in diameter at the butt, and over a foot in diameter at top, and 
having its bark in ridges, just like a cog-wheel, was raised a few 
years ago, it having a quite different appearance to the sticks gene- 
rally found. The timber had an appearance somewhat similar to 
the “yellow pine” now imported. 

In the country north-west of Lake Superior, between Port 
Arthur and the Lake of the Woods, during the making of the 
Canadian North Pacific Railway, sections in peat now overgrown 
with timber were laid open. In them, as in the Irish bogs, timber 
had grown prior to the accumulation of the peat; but time did not 
allow of making special examinations. The fact, therefore, is only 
mentioned to show that there, as well as in Ireland, climatic 
or some other natural change will account for the records of the 


634 Scientific Proceedings, Royal Dublin Society. 


different forest periods that occur, separated by a growth of peat. 
The time between the destruction of a forest and its re-growth may, 
in a measure, be learned in the province of Quebec. During the 
French and early English occupations all the low country between 
Quebec and Montreal was by the lumberers cleared of timber; now 
again it is a wood; not good marketable timber in the Canadian 
opinion, but as gross as the majority of firs to be found im the 
“ Home country.” These secondary woods are interesting, not only 
as to the re-growth of timber but also as to preserves for animal 
life; because as the country was cleared of its timber the wild 
animals retreated before the lumberers. Now, however, they have 
tried back, and in some of this re-grown bush, which is still con- 
sidered the ‘“‘ old country,” there is a better head of game than can 
be found even far up in the as yet undisturbed forests. Perhaps, 
however, the expression “tried back” is incorrect, as the animals 
more probably emigrated from their haunts in the as yet undis- 
turbed north-east portion of the province. 

In connection with our subject, the following information about 
the Fermanagh peat and timber, received since the paper was read 
from Mr. Thomas Plunkett, M.R.I.A., is of interest :— 

To the west of Upper or South Lough Erne, on the hills, there 
is boulder drift, it at the bottom of the slopes being replaced or 
overlaid by brickclay. From these slopes the flats extend eastward 
in the river valleys to and beyond the lake; and from the canals 
opened in these flats it has been learned that in them there are five 
to six feet of alluvium (silt), above one to two feet of peat with 
timber, they resting on the glacial drift. The peat is flaky, and 
full of flagger-like plants (lonagay turf of Munster), and the 
timber is principally oak, some of the “sticks” being over forty feet 
long and five feet in diameter. This timber must have grown on 
a surface below the drainage outlets of the river flats west of Upper 
Lough Erne. In the low country east of the two lakes there are 
different saucer or dish-shaped lake basins, in which roots of trees in 
situ occur below their summer level: such as at Drumgay and the 
Mill lakes north of Enniskillen, and in two lakes in Castlecoole 
demesne. 

To the eastward of Upper Lough Hrne, on the sloping terrace 
round the top of Topped Mountain, there is a pagan cemetery, 
now covered by five or six feet of peat. On the flanks of the hill 


Kinanan—Deal Timber in the Lake Basins of Donegal. 635 


there is sloping bog, and in the cooms, deep flat bog, and under 
the peat in the latter (from 10 to 25 feet deep) large roots in situ 
and sticks of deal and oak; one that was stepped being over 60 feet 
long and at the broken-off top over six inches in diameter. The 
floors of these flat bogs are saucer or dish-shaped basins, below the 
present drainage outlets. In the hills westward of Lough Erne 
there are also similar lakes to those in the low country, their basins 
being saucer-shaped, and having timber roots in sitw below summer 
water-level. 

Mr. Plunkett points out that the pagan cemetery now covered 
with peat, the trees on the hills of greater size than those which 
now grow on the low country, and the peat under the Upper 
Lough Erne flats, prove that the climate was, during the timber age, 
much drier and warmer than at present. This was succeeded by a 
wetter period, during which the woods on the flats became reedy 
marshes, while in the cooms in the hills and on their slopes mosses 
and such like grew; these peaty accumulations not only stopping 
the growth of the timber, but also destroying the woods and 
changing them into bogs. This was succeeded by still more rainy 
times, during which the flats of the tributary rivers of Upper 
Lough Erne were flooded by sheets of turbid water, the sill from 
which floods buried the “monagay turf,’ with its timbers, under 
the present overstratum of silt. 

To account for the trees growing in the flats and hollows with- 
out drainage outlets, he suggests that during the period when there 
was little rain and great heat, all the rain that fell in the hollows 
was required by the trees, but if perchance there was a surplus, it 
was evaporated—this is known to take place in America at the 
present day, as in the “cedar swamps” and other “‘swamps”’ diffe- 
rent kinds of trees grow luxuriantly in places without drainage 
outlets—also, when the rain became greater and the heat less, the 
moisture became excessive, generating the marshes in the flat and 
the peat in the hill, thus destroying the forests and burying the 
pagan cemetery. 


pete | 


LVI.—GRAVEL TERRACES; VALLEYS OF THE MOURNE, 
STRULE, AND FOYLE, COUNTIES TYRONE AND 
DONEGAL. By G. H. KINAHAN, M.RB.1.A. 


[Read, June 1, 1887.] 


[The rivers of Tyrone have a multiplicity of names, as the main rivers and their 
tributaries, as often as they fork, are each given a new name: thus at Strabane the 
branches of the Foyle are called the Finn and the Mourne, while the latter, at every 
divide, has different names: the valley to which we would draw special attention is 
that now utilized by the railway from Omagh, by Strabane, to Derry, occupied prin- 
cipally by the Mourne. ] 


A TRAVELLER along the valley from Omagh to Strabane, and 
thence along the Foyle to Londonderry, may observe the series of 
terraces in the margining hill slopes, they disappearing in the 
vicinity of Derry; while if he goes north-westward into the valley 
of the Swilly he will not find any. This remarkable difference in 
the adjuncts of the Foyle and Swilly valleys has led to research 
and reflection. 

In connection with Lough Swilly we find it among the loughs 
mentioned in the Annals as having “broken forth” during his- 
torical times. As so many loughs, both sea loughs and inland 
loughs, are mentioned as having “ broken forth” at different times, 
there must be some reason for the records; the following sugges- 
tions, therefore, may not be out of place. As pointed out in the 
previous Paper (ante, p. 632), the climate of Ulster, before the later 
bogs began to grow, must have been somewhat similar to that of 
the country adjoining the St. Lawrence! at the present time. In 
this part of Canada there is great heat in summer and great cold 
in winter, with a small rainfall. Such climatic conditions in 
Ireland may have caused some of the present sea loughs to have 
become filled with ice; while some of the present lake basins (as sug- 
gested by Mr. Plunkett of Enniskillen, ante, p. 634), may have 
been hollows occupied by forests. A gradual amelioration of the 
climate ought, however, to affect the necessary changes; because 


1 The stone walls of huts similar to those now inhabited by the Lapps and other 
inhabitants of North Europe, as figured by Du Chaillu and by Nordenskjéld, in the 
voyage of the Vega, are not uncommon in places in the Co, Donegal. 


KinaHan—On Gravel Terraces. 637 


as the winters become less cold, the summer less warm, and the 
rain-fall greater, the ice in the bays would gradually disappear, 
while as the evaporation was less, the hollows would become lakes, 
thus accounting for the “breaking forth” of the different inland 
and sea loughs.!. This digression, although it may have a certain 
interest, does not seem to account for the great difference in the 
features of the marginal slopes of the valleys of Loughs Swilly and 
Foyle; but during a recent traverse of western Tyrone and Fer- 
managh it occurred to me that the phenomena in connection with 
the latter may possibly be explained by what is found at the 
present time in the river valleys of the “Foot Hills” of the 
Canadian Rockies. 

Let us suppose that when the climatic conditions of Ulster were 
more or less similar to those of Canada at the present day, the 
Silurian hills (Lower Old Red Sandstone type) east of the plain of 
the Loughs Erne, and extending eastward nearly to Cookstown 
(which for convenience sake may be called the “ Fintona moun- 
tains,’ after the town nearly in their centre), was a snow-field 
feeding small glaciers in the upper portion of each valley, while in 
each valley there was a river thick with silt and sand, each also 
being margined by gravel terraces. This may be seen at the 
present day in the upper portions of Bow and Belly rivers, Alberta, 
and in other river valleys east and west of the Canadian Rockies. 

Many circumstances in connection with the surroundings of the 
“Fintona mountains” seem to support such suggestions. To the 
westward in the low country of the Loughs Hrne the gravels seem 
to partake more of the character of glacial than marine accumu- 
lations; at the ‘divide,’ Pomeroy, in the central east and west 
valley, there is an excessive accumulation of sand and gravel, as at 
the “divides” of the river valleys in the Rockies between two 
glacial rivers or valleys; while the gravel terraces along the slopes 
and the flats of the Strule, Mourne, and Foyle valleys, if we allow 
for the subsequent modification due to meteoric denudations, are 
very similar to those of the Bow river, Alberta. 

The genesis of these terraces in the valleys of the rivers of the 


1 Some lakes may have ‘‘ broken forth,’’ on account of a change in the level of 
the land, as I have elsewhere suggested, giving reasons in connexion with Galway Bay 
and Lough Corrib, 


638 Scientific Proceedings, Royal Dublin Society. 


“Foot hills” has not as yet been satisfactorily explained ; it is, 
however, evident that they are adjuncts of rivers from an alpine 
region. ‘They die out as the lower open valley is reached, while 
elsewhere they are connected with greater or less flats. As their 
different characteristics are common both to the present Canadian 
and these ancient Irish river valleys, it seems not improbable that 
the terraces in both had a common origin. 

It may be pointed out that the term “ Esker gravel” seems 
to be getting very mixed. “Esker gravel”—proper—is the 
gravel due to the action of the ‘“ Esker sea”’ that once occupied 
the central plain of Ireland. Now, however, both in Ireland 
and America the term is being applied to all gravels if heaped up 
in ridges. ‘This in one sense is correct, as all are “eskers,” i.e. 
ridges; but the term ought to be restricted to marine gravels. 
This is not the case in the Co. Fermanagh, or in different places 
in the United States of America, where drift called eskers or 
kams is evidently either of fluvial or glacial origin. Such, it 
would appear, was the origin of most of the gravels of Fermanagh 
and western Tyrone. But in south-east Tyrone it would appear 
as if the “‘ Esker sea”’ came into some, at least, of the valleys, thus 
causing a blending of the Esker sea and the glacial gravels. <A 
similar phenomenon may possibly also have taken place in the 
lower levels in the Co. Fermanagh, as the surface of Lower 
Lough Erne is about 150 feet over ordinary low water in Donegal 
Bay. 


[ 639 ] 


LVII.—ON THE INVERSION OF CENTROBARIC BODIES. 
By THOMAS PRESTON, B.A. 


[Communicated by Professor G. F. Firz Grraxp. | 


[ Read, June 1, 1887.] 


Ir M be any figure, and O a fixed origin, and if to each point P 


of M a corresponding point P’ be taken on the radius vector OP, 
such that 


OP. OP’ = a constant = a’, (1) 


a figure IY is obtained, which is termed the inverse of I. 


Now if IZ be any continuous mass or any distribution of 
matter, and if at P’ an element of mass dm’ be placed, such that 


dm = - di, (2) 


where dm is the element of mass at P, and r = OP, we obtain a 
distribution of matter I/’, the density p’ of which at any point P’ 
is connected with the density p of M at the corresponding point P, 


by the equation 
aN? Pe ‘ 
Pol) pels 3 


where 7’ = OP’. This equation follows at once from the relation 
dv : dv’ =r° : a°; the elements of volume at P and P’ being dv 
and dv’. 


640 Scientific Proceedings, Royal Dublin Society. 


Hence, if the density of If be uniform, the density at any point 
of WW’ will vary inversely as the fifth power of its distance from O. 
So also, if If be a uniform superficial distribution, IZ’ will be a 
superficial distribution of density varying inversely as the cube of 
the distance from 0. 

It may be remarked that if, in equation (3), p varies inversely 
as the fifth power of 7, then p’ is uniform ; that is, if If’ be inverted 
from O the inverse mass will be of uniform density. However, if 
any other origin O’ be taken, and if I’ be inverted with respect to 
O' and a radius a’, then the density p” of this second derived dis- 
tribution will be given by the equation 


b (OE , (OR (a 
OTN Rate ae ter ap) ° 
c /a 0’ 0” F 
ma \a 0 P’ 0” P» 


where O” is the inverse of O with respect to 0’. Hence the density 
of J”, the inverse of I’ with respect to O’, varies inversely as the 
fifth power of the point from O”, the inverse of 0’. 

Or a body, the density of which varies inversely as the fifth power 
of the distance from a fixed point inverts into a body of density, vary- 
ing inversely as the fifth power of the distance from the inverse point. 

Again, for the total mass of I’ we have 


mw =| an =(* dm =a [= aM, (4) 
where JV, is the potential of the mass I at the origin O. 

It is also easily seen that V, the potential of Mat any point A, 
“is connected with V’, the potential of I’ at the inverse point A’, 
by the equation. (Thomson and Tait, Natural Philosophy, Part 11. 
Art. 516). 


V'= a V. (5) 


CasE oF A CENTROBARIC Bopy. 


If the mass J/ be centrobaric, that is, such that it attracts any 
other portion of matter as if all its mass were collected at C, its 


Preston—On Centrobaric Bodies. 641 


centre of inertia, we have for the potential of If at A 


M 
excaer 


Therefore, by equation (5) the potential V’ of MW’ at A’ is given by 


v.04 M_O¢ M__«.M 

7 ae AG) Or + EO. OG, 
where C’ is the inverse of C.. But I/OC is the potential of I at 
O; therefore by (4) we have 
ey, 
re A’ CO’ b) 
that is, the potential of I/’ at any point A’ is the same as if all its 
mass were concentrated at C’, the inverse of C. Hence we have 
the following 


Va 


THEOREM. 


Tf any mass M be centrobaric, the inverse mass M’ is also centro- 
baric, and the centre of mass of the latter is the inverse of the centre of 
mass of the former. 


THomson’s THEOREMS. 


Since a uniform sphere is a centrobaric body, attracting any 
external matter as if its mass were all concentrated at its centre, 
we have at once the following theorems of Sir W. Thomson :— 

(1). A sphere, the density of which varies inversely as the 
distance from a fixed point O, attracts any other portion of matter 
as if its mass were all collected at a certain point, viz. the inverse 
of O with respect to the sphere. 

[For the inverse of a uniform sphere is a sphere, the density of 
which varies inversely as the fifth power of, the distance from the 
origin, and the inverse of its centre is the inverse of the origin with 
respect to the inverse sphere. | 

(2). An infinitely thin shell, the density of which varies in- 
versely as the cube of the distance from a fixed point 0, attracts 
any other portion of matter as if the mass of the shell were all 


concentrated at a point, viz. the inverse of O with respect to the 
shell. 


[ 642 ] 


LVIUI.—ON A MECHANICAL METHOD OF CONVERTING 
HOUR-ANGLE AND DECLINATION INTO ALTI- 
TUDE AND AZIMUTH, AND OF SOLVING OTHER 
PROBLEMS IN SPHERICAL TRIGONOMETRY. By 
A. A. RAMBAUT. 


[Read, April 20, 1887.] 


Tux principle of this instrument is by no means new. It was in- 
vented by De St. Rigaud, a Jesuit father, about the beginning of 
the seventeenth century, in the form ofa sundial, which is described 
in the ninth edition of the Encyclopedia Britannica. 

The application of the principle, however, to the problem of 
converting the place of a star from one set of co-ordinates to 
another has never, so far as I am aware, been pointed out. 

In the spherical triangle, whose vertices are the pole, the zenith, 
and the star, and whose sides are, therefore, the complements of 
the latitude, the declination, and the altitude respectively, while 
its angles are the hour-angle, parallatic angle, and north azimuth, 
we have the following relations :— 


sin f = sin 6 sin + cos 0 cos ¢ cost, (1) 
and sin 6 = sinh sin } + cosh cos } cos A, (2) 
in which h = altitude, A = azimuth, 
© = declination, ¢ = hour-angle, 
@ = latitude. 


The construction due to De St. Rigaud, and on which the 
principle of this instrument is based, is as follows :— 

With C as centre, and AC as radius (see fig. 1), describe a 
semicircle. Draw CF at right angles to AC. Make the angle 
FAC equal to the latitude. Draw FZ at right angles to AF. 

Now to find a star’s altitude, being given its hour-angle and 
declination, make FAG equal to the declination, and ACD equal 
to the hour-angle. Draw DE at right angles to AC. With Gas 
centre, and GA as radius, describe a circle cutting DE in J. Then 
the angle between GZ and FC is the altitude. 


RamBaut—Converting Hour-angle and Declination, &c. 648 
To prove this, draw GX parallel to FC and GH, and IK at 


right angles to it. ‘Then 


: IK HG+EHC 
oe ee 
_HG FG EC AO AF 
FG AG CD’ AF’ AG 
= sind sing + cos 6 cos¢ cost. 


Therefore [GK = h. : 

Equation (2) may be obtained from (1) by writing A and h for 
¢ and 6 respectively, and vice versa. We thus see that if FAG =h, 
and IGE = 6, then ACD = A. 

The instrument which I have to describe consists of a circle If, 
graduated in hours and minutes on the inner side of the circum- 
ference, and in degrees on the outer side, to facilitate the readings 
of hour-angles and azimuths respectively. There is a straight 
edge corresponding to the line #'Z in figure 1 graduated, so as to 
read, at any point G (fig. 1), the angle between the lines 4F' and 
AG, and along this slides a piece VO which carries a pointer, and 
can be set at any required graduation. 


644 Scientific Proceedings, Royal Dublin Society. 


Round a pivot X fixed in NO rotates a slotted piece R, which 
can be clamped at U to the disc V, the edge of which disc is 
graduated in degrees. A pointer Q is attached to the piece VO. 


Y 


HU 


Fig. 2. 


P is a cylindrical pin passing through #& at right angles. Finally 
ST is a straight edge, which is always at right angles to YZ (or to 
AC, fig. 1), along which it slides. 

Now in fig. 1 the angle between JG and GZ is¢+h. Accord- 
ingly, by causing the direction of the zero of the graduation on V 
(fig. 2) to make an angle @ with that of #, the pointer Q reads the 
altitude directly. 

Wo find the Altitude of a star, therefore, it is necessary to set 
NO to the declination. Unclamp U, and bring P up to the point A 
(fig. 1). Clamp U. Slide STalong YZ till it cuts the circle If at 
the hour-angle. Rotate & till P touches ST. Then the pointer Q 
reads off the altitude. 


RamBaut—Oonverting Hour-angle and Declination, &c. 645 


To find the Azimuth, set VO to the altitude which we have 
just found. Unclamp JU, and bring P up to the point A (fig. 1). 
Clamp JU, and rotate R till Q reads the declination. Slide S7 till 
it comes into contact with P, and its intersection with the circle I 
will then give the azimuth. 

Since the section of the pin P is not a point, but a circle of con- 
siderable radius, in consequence of which ST is always too far to 
the right by the length of the radius of P, it is necessary to shift 
the circle Mf to the right by the same amount without altering its 
radius. 

There are some other problems of minor interest which this 
instrument solves very easily. 

For instance, the time of rising or setting of a heavenly body 
corrected, if necessary, for refraction, can be very easily obtained. 
For, since the horizontal refraction may be taken at 36’, it is only 
necessary to set VO to the declination of the body, and the pointer 
@ to — 36’, and the point where SZ cuts the circle WV, when in 
contact with P, then gives the hour-angle of rising or setting. 

To find the length of twilight on any given day, find the time 
of sunset as above. Then, by rotating the piece F till Q reads 
— 18°, we get the hour-angle of the sun when 18° below the 
horizon, which gives the end of twilight. 

For stars near the pole, or when a star is approaching the 
zenith, the rapid increase in the tangents of the declination and 
altitude will render the determination of the altitude or azimuth 
difficult, if not impossible. 


SCIEN. PROC. R.D.S.—VOL. V., PT. VIII. 2Y 


[ 646 ] 


LIX.—ON TWISTED COPPER WIRE. By S. M. DIXON. 


[Communicated by Prorzssor G. F. Firz Gzratp]. 


[Read, June 1, 1887.] 


Tr a piece of copper wire be given a great number of turns of 
permanent longitudinal twist, some of its physical properties are 
found to be greatly changed. It is no longer ductile, and it breaks 
instead of receiving a large permanent set, when it is distorted 
beyond its limit of elasticity. 

_ The question naturally arises, How have the moduluses of 
elasticity been changed by this permanent twist? To answer this 
the following experiments were made :— 

Some ordinary commercial copper wire, such as is used by 
bell-hangers, was taken. Its specific gravity was found to be 
8:915, and from this its diameter was calculated to be 03898 
inch. This wire was then hung perpendicularly, the upper end 
being firmly fixed to a rigid support, and on the lower end was 
screwed a small vice, with a hook carrying a scale-pan, which 
weighed 1lb. <A weight of 4 lbs. was placed in this, the wire 
being thus almost completely freed from kinks. Young’s modulus 
for this wire was then found to be 8,000,000 lbs. per square inch, 
and it could be loaded with 14 lbs. without any appreciable 
permanent set being produced, the wire being broken by 343 lbs. 
Several experiments were made with more of this wire, and the 
mean results are given in the Table at the end of this Paper. 

Twenty-seven feet of the wire were then given 4900 turns of 
permanent longitudinal twist. The mode of twisting was as 
follows :—One end of the wire was clamped to the armature of a 
Gramme’s magneto-electric machine, which was driven by two 
Grove’s cells. The other end of the wire was fastened to a 
movable support. This support had to be moved slowly from the 
Gramme, as the wire increased in length as it was twisted. ‘The 
number of turns given to the wire was counted by means of a 
velocimeter held on the Gramme. ‘The first experiment showed 
that the specific gravity had diminished; but this result was found 


Dixon—On Twisted Copper Wire. 647 


to have been falsified by the air which adhered to the roughened 
surface of the wire, for on boiling the wire in water, the specific 
gravity then found was identical with that of the untwisted 
wire. ‘The diameter of the wire was reduced to :0382 inch. 

On making experiments on this wire similar to those made on 
the ordinary wire, Young’s modulus was found to have increased 
to 14,500,000, its breaking weight to 42 lbs., and 284 lbs. were 
necessary to produce a permanent set. 

By drawing the first wire slowly by a weight, gradually in- 
creased to its breaking weight, Young’s modulus became 15,000,000, 
which was practically the same value as the modulus of a piece of 
wire twisted till it broke. 

To find the effect of twisting a wire which already had a 
permanent set, 14 feet of the drawn wire were given 3200 turns 
of permanent twist. Now, although it increased in length, as did 
the first wire, still its breaking weight was unaltered: Young’s 
modulus was reduced to 11,500,000 Ibs. per square inch, and 21 lbs. 
produced a permanent set. 

The next experiment shows how much the limit of elasticity 
for bending was altered, Young’s modulus being hardly changed. 
A piece of copper wire 12 inches long and =); inch diameter was 
given 180 turns of permanent twist in the lathe. This wire was 
then held horizontally by one end being clamped in a vice, while 
from the other was suspended a light pan for carrying weights. It 
was now found necessary to load the pan with 1 lb. to produce a 
permanent set. For a piece of ordinary wire of the same dimen- 
sions 1 of this weight produced a permanent set. Yet in the case 
of these two wires there was. very little difference in Young’s 
modulus, the values of it being 12,500,000 and 12,000,000 lbs. 

‘ per square inch respectively. 

When a wire had once been given a permanent set by twisting, 
it was found that turning the wire in either direction had exactly 
the same effect. For example, three pieces of wire, each 4 feet 
long, broke when given 1430, 1380, and 1420 turns respectively; 
and when a piece of wire of the same length was first given 700 
turns in one direction, it broke when twisted 696 times back in 
the contrary direction. 

Wire ‘0398 inch diameter, when given an average of 30 turns 
to an inch, was so brittle that it could not be wound on a 


648 Scientific Proceedings, Royal Dublin Society. 


cylinder ‘9 inch without breaking. 


found to have increased 8:3 per cent. 


The electrical resistance was 


TABLE giving the Mean Results of Experiments made on the Elasticity 
of Twisted Copper :— 


Ordinary Wire, 


Ordinary Wire twisted, . 


Ordinary Wire drawn 
by breaking weight, 


Drawn Wire twisted, 


Young’s Modulus | Weight producing 
in millions permanent set, 
of Ibs. per sq. inch.| in lbs. per sq. inch. 


7-6 16,200 
15-0 32,900 
15:0 me 


11:5 24,600 


Breaking weight 
in lbs. per square 
inch. 


37,900 
49,300 
37,900 


37,900 


[ 649 J 


LX.—ON THE EFFECT OF CONTINENTAL LAND IN ALTER- 
ING THE LEVEL OF THE OCEAN. By EDWARD 
HULL, LL.D., F.R.S., &c., Director of the Geological 
Survey of Ireland. 


[Read, March 23, 1887.] 


WHEN looking into the work of Professor Edward Suess, ‘“ Das 
Antlitz der Erde,” ’ I was much surprised on lighting on a passage 
in which the author appears to adopt the view, that in some cases 
the level of the surface of the ocean along the margin of a conti- 
nent may be as much as 1100 metres (or 3380 Parisian feet) above 
that of the surface along the shores of a mid-oceanic island ; that is 
to say, so much further from the centre of the earth in the same 
parallel. This statement is founded on a formula adopted by 
Fischer? for the determination of the relative levels by means of 
oscillations of the daily second’s pendulum at different stations 
along a continental coast, and a mid-oceanic island, to the effect 
that the amount in metres will be nearly 122 times the difference 
in the number of such oscillations. No special stations are men- 
tioned ; but he takes an example where the difference in the num- 
ber of oscillations amounts to nine, giving the result of 1100 metres 
(in round numbers), above stated. In any case this is sufficiently 
startling, and, if correct, would be a great advance on the views 
generally held on this subject. If correct, even approximately, it 
is clear that large portions of continental lands are submerged 
which would otherwise be uncovered; while many islands owe their 
existence as such to the abnormal lowering of the ocean surface at 
a distance far removed from continents. 

To some extent this is true; but the question arises, to what 
extent even in extreme cases. 

As the length of the second’s pendulum is proportionate to the 


1 « Das Antlitz der Erde,’’ Ist Abteil., p. 3 (1883). 
2 Fischer, ‘‘ Untersuchungen tiber die Gestalt der Erde ’’ (1868). 


650 Scientific Proceedings, Royal Dublin Society. 


attraction of gravitation, and, therefore, with some corrections for 
local irregularities, to the distance from the centre of the earth, we 
have a means of ascertaining approximately the ocean-level at 
different points ; and numerous observations of the length of the 
pendulum have been made both on continents and in islands. 
These have been collected by Airy in his elaborate article on ‘“ The 
Figure of the Earth,” published in the Encyclopedia Metropolitana, 
from which I extract a few special examples. It will be observed 
that the length is mainly determined by the latitude. The obser- 
vations were originally made by Sabine, Biot, and others, and are 
considered by Airy as ‘first-rate observations” in contradistinc- 
tion to others, which he classes as “‘ second-rate.” ! 


Observed length of Difference 
Station. Latitude. Second Pendulum in i 


English inches. Vibrations’ 
Spitzbergen, : - 197 BOON. ye 89-2469) ee emtce 
Hammerfest, s . TO 40 es 19475 . . —O4 
Stockholm, : 5 tg) Ll eke 16541 . . +0°5 
London, . : ably Bt Bale “3929 nee 
Paris, ; : . 48 50 agit 28515 2) 2 wld, 
Bordeaux, . ‘ 44 50 ais 11296. . -37 
Toulon, : 4 Su Oras apie 10952. . —O-1 
California (? Mexico), . 21 380 suis 708829 . . -6:0 
Sandwich Islands, 5 | D0) BR shee 14690) 2) 2 
Jamaica, . 5 5 I &G ae 035038 . . -—08 
Marian (or Marianne) 13 28 ro 033879... | aneas 

Islands, ; 

Sierra Leone, . 2 81 30 ai -O199%.) 2) eles 
Sieh oma ee 5 © US Bei 02074 . . +44 
Ascension Island, OT: SD Oui Oem earns 02368 . . +3°4 


The name “ California” in the above Table is clearly a mistake, 
if we go by the latitude, which is the more reliable of the two. 
California, as at present represented on our maps, does not reach 
so far south as 21° 30’ N. latitude. The cause of the decrease in 
the length of the second’s pendulum, as we proceed from the poles 
towards the equator, is twofold—first, on account of the in- 


1 Airy, ‘‘ Figure of the Earth,’’ Encyclopedia Metropolitana, vol. v., p. 229. 
2 Island in Gulf of Guinea. 


Hutit— On the Effect of Continental Land on Level of Ocean. 651 


creasing distance of bodies on the earth’s surface from the centre of 
the earth, due to the oblate-spheroidal form of the earth itself; and, 
secondly, on account of the decrease of gravity due to the increas- 
ing centrifugal force depending on the velocity of the earth’s rota- 
tion. Both these causes act in the same direction in lessening the 
gravity of bodies towards the equator; and, as a consequence, 
causing a decrease in the length of the second’s pendulum. The 
total variation in the length between those at the equator and 
the poles amounts to 0°222 of an inch.! 

‘From the data thus obtained we can determine the number of 
oscillations of a pendulum of the same length (or the same pendu- 
lum) on a continental and oceanic station; and, applying the for- 
mula stated by Suess, viz. 122 times the difference in the number 
of oscillations at two stations on (nearly) the same latitude, we 
obtain the result in métres. 

The results of the German physicists will probably surprise 
many who have been under the impression that the difference 
of level of the surface of the ocean, relatively to a geodetic 
surface, does not very much vary. Comparing the maximum 
and minimum results, it will be observed that the difference 
of level between California (or Mexico) and the Sandwich Islands 
amounts to no less than 4520 feet. The great rise in the ocean 
surface along the coast of California is accounted for by the extent 
and elevation of the mountain ranges along the American coast ; 
and this notwithstanding the existence of the Gulf between the 
peninsula and the main land. The attractive influence of a moun- 
tain range near the coast is here clearly illustrated; and even more 
remarkable results might be expected, were a comparison instituted 
between stations on the coast of Peru and the Marquesas, or Society 
Islands, in the centre of the Pacific.’ 

Having called the attention of the President of the Royal 
Society, Professor G. G. Stokes, to the statement in Suess’s work, 
in which his name appears, and requesting his views thereon, I 
have been favoured with the following reply, which is inserted by 
permission :— 


1 Haughton, ‘‘ Natural Philosophy.”’ 
2 It is greatly to be desired that pendulum observations should be undertaken on 
the Peruvian coast. The Sandwich Islands would then answer for comparison. 


652. Scientific Proceedings, Royal Dublin Society. 


‘‘ LENSFIELD CotTacE, CAMBRIDGE, 
“26th February, 1887. 


‘¢My pear Sir,— 


‘“‘T am afraid you will think I have forgotten the question you 
asked me in your letter. It is not so. But I thought that before 
answering it I would look into Professor Suess’s book, if I could find 
it. It is not, however, either in the University Library or in that of 
the Royal Society. But if I had found it I do not know that I should 
have been much the wiser; for, as you say, he gives no numerical 
data as to the dimensions of the supposed continent, nor does he 
specify what the continent actually is, if he is dealing with areal, not an 
ideal, continent. 

‘‘Tn a Paper ‘On the Variation of Gravity at the Surface of the 
Farth,’ which I wrote long ago, and which is published in the 
Transactions of the Cambridge Philosophical Society,’ and in my collected 
Papers, of which as yet only two volumes have appeared, I showed 
that the effect of a continent would be to make a slight apparent 
diminution of gravity in continental stations as compared with de- 
tached oceanic islands. It operates in this way :—that the attraction 
of the land causes the surface of the sea level, the level surface, that is, 
which would be determined by a system of geodetic levelling carried 
from the coast inwards, to stand higher from the centre of the earth 
than it would have done had the place of the continent been occupied 
by ocean. The raising of the sea-level is greatest inland; but it is 
quite sensible, and even important, at the coast itself of the continent. 

‘‘How much the rising amounts to depends, of course, on the 
dimensions you attribute to the continent, and the height you give it 
above the undisturbed level of the sea. To take a numerical example, 
I suppose the case of a circular island or continent, whichever you 
please to call it, one thousand miles in diameter, and elevated a quarter 
of a mile above the sea-level. I suppose the depth of the ocean, in 
which this island is supposed to be placed, to be two miles. 
I make the usual suppositions as to the average density of the 
rocks, &c., in the neighbourhood of the earth’s surface, and as to 
the mean density of the earth, which is fairly well ascertained. I 
find the elevation of the sea-level in the interior of the island, 
or continent (Australia), a good way from the coast, to be about 


1 Vol. viii. (1849), pp. 672-695. 


Hutt—On the Effect of Continental Land on Level of Ocean. 658 


four hundred feet. Of course in a great continent it might be con- 
siderably greater. This would cause an apparent diminution of gravity 
in continental stations—I mean, of course, in gravity as reduced by 
the usual methods to the level of the sea. In the first place, in re- 
ducing to the level of the sea we leave out of consideration the attrac- 
tion of the stratum of earth between the actual sea-level and what the 
sea-level would have been if the continent had been away. As far as 
this goes, corrected gravity ought to appear too great. But in the 
second place, in reducing to the level of the sea, we reduce to a point 
further from the centre of the earth than we should have done if the 
sea-level had been unchanged ; and therefore in correcting we don’tadd 
enough to bring it up to what it would have been if ocean had been 
beneath us instead of land. On this account, therefore, gravity should 
appear too small—I mean reduced gravity. The two effects on ap- 
parent gravity are antagonistic, but the second is the stronger, so that 
on the whole gravity ought, ceteris paribus, to appear a little less on 
continents than on detached islands. Sabine and Airy have pointed 
out that such appears to be the result of observation ; but so far as I 
know, I was the first to point out that such a result ought to follow 
from the attraction of a continent by disturbing the sea-level. 

‘“‘Far inland the thing could only be tested in those cases where 
the sea-level has been accurately determined by geodetic operations. 
We could not accordingly throw much light on the question by means 
of pendulum observations in Thibet. 


“‘T am, dear sir, 


‘“« Yours very truly, 


‘“¢G. G. Sroxes. 
“H. Hurt, Esq., F. B.S. 


‘«P.§.—You will find Airy’s discussion in his article, ‘ Figure of 
the Earth,’ in the Encyclopedia Metropolitana. 

‘* An elevation of four hundred feet, even if there had been no in- 
tervening attraction to reduce the resulting diminution of gravity 
would only alter the number of vibrations per diem of a seconds pen- 
dulum by about oneand a-half. Of course, apart from disturbance, the 
difference in the number per diem at two stations on the same parallel 
of latitude would be nil, and therefore the small difference of 1:5 would 
be infinity times that. Ido not know what the term of comparison 
used by Fischer may be.” 


SCIEN. PROC. R.D.S.—VOL. V. PT. VIII. 2Z 


654 Scientific Proceedings, Royal Dublin Society. 


In the case, therefore, of a continental island a thousand miles 
across, and rising about 1320 feet above the sea-level, the effect 
of the attraction on the oceanic waters will be to raise the imagi- 
nary surface in the interior about 400 feet above a geodetically 
determined level; while the rise along the coast will be less. But 
Professor Stokes very truly adds, the effect in the case of a great 
continent might be considerably greater. Where, for instance, we 
have a continent such as that of South America, from 2000 to 
3000 miles across, risimg from an ocean of an average depth of 
15,000 feet, and bounded by the giant mountain range of the 
Andes, with an average level of 12,000 to 16,000 feet, who can say 
what the effect of the mutual attraction of this mass of land on the 
surface of the Pacific Ocean may amount to? Certainly consider- 
ably more than in the hypothetical case of Professor Stokes. In 
certain cases the effect of this rise, in altering the superficial 
areas of land and sea would be very considerable; but, owing 
to the comparatively steep gradients of the coast and mountain 
slopes, as well as of the submerged portions along the Pacific 
borders, the effect in diminishing the area of submerged marginal 
lands is less apparent than if the gradients were more gentle. 

The same observations apply, in a less degree, to North 
America. 

The effect of such an arrangement of the configuration of ocean 
and continent as is presented along the western sea-boards of the 
American continents, where extensive mountain ranges and ele- 
vated plateaus stretch for thousands of miles along the borders of 
a deep ocean, must be much greater than is generally supposed. 
The orographical characters of these continents, ‘and their relations 
to the oceanic waters, may be regarded as affording the required 
conditions for bringing about a maximum result in the elevation 
of the ocean-surface. The most powerful attractive force is that 
exercised by the lands immediately adjoining the sea-board ; and 
as we recede from this line inland the attractive force necessarily 
diminishes as the square of the distance. Hence the conditions 
required for the maximum effect are found when there is an 
accumulation of solid matter in the form of mountain ranges close 
to the coast-line; and this is exactly what happens in the case of 
the American continents. Judging from the elevations and 
breadth of the range of the Andes of Peru, and Bolivia, in South 


Hvutit—On the Effect of Continental Land on Level of Ocean. 655 


America, and of the Rocky Mountains of Mexico, in the northern 
continent, it may be assumed that the ocean surface reaches a 
higher level along these portions of the coast than elsewhere. 

The general result of our inquiries seems to be, that the form of 
a geodetic section of the earth, taken parallel to the equator, and 
at successive intervals both to the north and south of that line, 
would give curves of ever-varying irregularity according to the 
position of land and water. That there must be a very important 
variation from the mean ellipsoidal form along the western margin 
of the two Americas it is impossible to doubt. Bulgings to a 
smaller extent may be inferred along the coast-lines. It is prob- 
able that these equalize one another over the whole surface of the 
globe; and, as compared with the diameter of the globe, they are 
unimportant. Nevertheless, the effect of the elevation and depres- 
sion of the ocean surface must have been felt throughout all geolo- 
gical time. The effect of the uprising of mountain chains, or the 
submersion of lands, in altering the ocean level, becomes an impor- 
tant element in the discussion of questions connected with the 
distribution of land and sea both in the present and in past geologic 
periods. 

I propose to continue the discussion of this subject on a future 
occasion, the present Paper being only of a preliminary character. 


END OF VOLUME V. 


Proc. R.D.S., N.S., Vol. 5. Plate I, 


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