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a 
) 


mo.4 


THE 


SCIENTIFIC PROCEEDINGS 


OF THE 


ROYAL DUBLIN SOCIETY. 


dle Series. 


VO UM ny ve 


DUBLIN: 
PUBLISHED BY THE ROYAL DUBLIN SOCIETY. 
PRINTED AT THE UNIVERSITY PRESS, BY PONSONBY & WELDRICK. 
1885. 


THE 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. 


LIST OF TE CONTRIBUTORS 


TO VOLUME FOUR, 


WITH REFERENCES TO THE SEVERAL ARTICLES CONTRIBUTED 


BY EACH. 


Auten, Wituiam N.. 


Artificially-produced Gold Crystals, 


Baty, Wituiam H., F.G.S. 


On Trilobites and other Fossils, from Lower or Cambro- 
Silurian Strata, in the County of Clare, 


Batu, VaLentine, M.A., F.R.S., F.G.8. 


On some Effects produced by Landslips and their Resem- 
blance to Phenomena which are generally attributed 
to other agencies (Plate I.), 


On recent Additions to our Knowledge of the Gold-bear- 
ing Rocks of Southern India, 


A Geologist’s Contribution to the History of Ancient 
India, i ; 


- On the Newly-discovered Sapphire Mines in the Himalayas, 
Buake, Henry A. 


Note on the Parturition of a West-Indian Bat, 


Brooks, H. St, Joun, B.A., M.B., B.Ch. 


The Osteology and Arthrology of the Haddock (Gadus 
Aiglefinus) (Plates V.-IX.), 


PAGE 


509 


373 


69 
393 


449 


166 


lv List of the Contributors. S ‘ 


Curtis, Antour Hix, LL.D., D.Sc. 


On the Pressure of Earth against a Retaining Wall, 


Dixon, Grorce Y., M.A. 


On Peachia hastata, 


Dreyer, J. L. E., Pu. D. 


Observation of the Transit of Venus, 1882, December 6th, 
made at the Armagh Observatory, 


Einexann, Professor. 


Notes of the Transit of Venus, 1882, as seen at the 
Crawford Observatory, Cork, December 6th, 1882, 


Ercx, Wentworth, LL.D. 
On an Abnormal Solar Spot, 


FitzGERAED, Grorce Francis, M.A., F.T.C.D., F.R.S. 


On Dr. Eddy’s Hypothesis that Radiant Heat is an 
Exception to the Second Law of Thermodynamics, 


Note on Dust Repulsion, : ; : 
On Currents of Gas in the Vortex Atom Tae of Gases, 


On a Method of Studying Transient Currents by means 
of an Electro-dynamometer, ; ; ‘ 


On a Non-sparking Dynamo, : : : 
On a Model Illustrating some Properties of the Ether, 


On an Analogy between Electric and Thermal Phe- 
nomena, é ; 


Note on the Specific Heat of the Ether, 


On some Methods of Measuring the Densities of Gases, . 


Grusr, Howarp, M.E., F.R.S. 


Note on the Effect of Flexure on the Performance of 
Telescopic Objectives, 


Notes on the Construction of Turret Clocks, 


399, 


49 


47 


491 


57 
338 
339 


341 
343 
406 


439 
477 
481 


149 
446 


List of the Contributors. 


Happon, Aurrep C., M.A. 


Description of an Apparatus for Demonstrating Systems 
of Classifications, &c., 


On the Generative and Urinary Ducts in Chitons (Plates 
X. and XI.), 


On a New Species of Haleampa (H. Andresii) from 
Malahide (Plate XVI.), 


On the Structure and Habits of Peachia hastata Gx 
(Plates XVII. and XVIII.), 


Note on the Blastodermic Vesicle of Mammals, 


Hart, H. C., B.A. 
The Flora of the Wexford and Waterford Coasts, 
On the Botany of the River Suir, . 


Harttey, W. N., F.R.S.E. 


A Simple Method of observing Faint Lines with Diffrac- 
tion Spectroscopes, 


On the Colouring Matters employed in the Illuminations 
of the ‘‘ Book of Kells,” 


Hastam, A. R. 
On Volatilization of Zinc from German-silver Alloys, 


Haveuton, Rev. §., M.D., F.T.C.D., F.R.S. 


Remarks on the Unusual Sunrises and Sunsets which 
characterised the close of the year 1883, 


Hunt, A. R., M.A., F.G.S. 


On the Action of Waves on Sea-beaches and Sea-bottoms, 


Jouy, J., B.E. 


On an Apparatus for obtaining Telegraphically the Read- 
ines of Meteorological Instruments placed at a distance 
from the Observer (Plates III. and IV.), 

Notes on the Microscopical Character of the Volcanic 
Ash from Krakatoa (Plates XII. and XIII.), 

On Photometers made of Solid Paraffin, or other Trans- 
lucent Substance, 


208 


241 


158 


291 


345 


v1 List of the Contributors. 


Kinauan, Grorce Henry, M.R.LA. 


On the Possibility of Gold being found in quantity in the 
County Wicklow, f ; : : ; 


Notes on the Classification of the Boulder-clays and their 
associated Gravels, 


Notes on some of the Irish Crystalline Iron Ores, . 


Notes on the Earthquake that took place in Essex on 
the Morning of April 22, 1884, . 


Notes on the Apatite of Buckingham, Ottawa County, 


Canadian Archean, or Pre-Cambrian Rocks, compared 
with some Irish Metamorphic Rocks, 


Notes on the Coal Seams of the Leinster and Tipperary 
Coal-fields (Plate XIV.), 


~ Kinanan, Grrrarp A. 


Coal Deposits of the North-west Territories of Canada, . 


Mc Nas, W. B., M.D., F.L.S. 
Note on the Botanical Topographical Divisions of Ireland, 


Remarks on the en oe or ee He of Vege- 
table Metagenesis, : ; i 


On the Structure of the Flower of Bonatea speciosa, Willd., 
On Apospory in the Thallophyta, 


Moncx, W. H. 8S. 
The Distribution of the Stars in Space, . 


Further Remarks on Star Distribution, . 


Muuuen, Bensamin H., B.A. 


On a Set of Musical Stones in the Science and Art 
Museum, Dublin, 


Ocitpy, J. D. 


Notes on Some Irish Fishes, 


PAGE 
39 


207 
306 


318 
347 


B49 


364 


211 


197 


451 


463 
166 


470 
493 


434 


510 


List of the Contributors. 


O’Retty, J. P., C.H. 


On the Calcite Crystals from the Iron Measures of the 
County Antrim (Plate IT.), 


The Amygdaloidal Limestone of Downhill, County Derry, 
Notes on the Phosphorite Nodules of Podolia, 


On De Rossi’s Seismical and Endodynamical Map of 
Italy, : : : : 5 : : 


On Beryl with Schorl in Glencullen Valley, . 


Note on the Occurrence of Granite Porphyry in the Three- 
rock Mountain, County Dublin, 


Pim, Greenwoop, M.A., F.L.S. 


A Contribution to the Natural History of the Hairs of 
the Andreecium (Plates XIX. and XX.), ° 


Note on an Abnormal Development of Picea Pinsappo, . 


Reynotps, J. Ewerson, M.D. F.R.S. 


Note on Seleno-Carbamide, . 


Riesy, Joun, M.A. 
Velocity and Energy of Small Shot, 


Sottas, W. J., M.A., D.Sce., F.G.S. 
On the Origin of Freshwater Faunas (Abstract), 


Physical Characters of Caleareous and Siliceous Sponge- 
spicules (Plate XV.), 


On an Hexactinellid Sponge from the Gault, and a 
Lithistid from the Lias of England (Plate XXI.), 


Stonry, GEoRGE GERALD. 


On Gearing for Bicycles and Tricycles, . 


vil 


PAGE 


419 
508 


437 


238 


O74 


443 


20 


vill List of the Contributors. 


Stoney, GrorcE Jounstone, D.Sc., F.R.S. 


On Gearing for Bicycles and Tricycles, . 


On Modes of Dealing with Echoes in Rooms, 


On Equal Temperament, and the Cause of the Effect upon 
Piano Music produced by the Key in which it is set, . 


On the Possibility of Prolonging the Tones of a Piano- 
forte so as to produce an Instrument with the Quality 
of Tone of the Piano, and the Continuity of Tone of 


the Organ, 


TicHBorne, C. R. C., LL.D., F.C.S. 


On an Argentiferous Galenetic-Blende at Ovoca, 


Txomson, Jocetyn H., Lieut. R.A. 


Curious Numerical Relations of the Musical Seale, 


Witson, W. E., F.R.S.A. 


Notes on the Transit of Venus, as observed at Streete, 


County Westmeath, . 


- PAGE 


20° 
58 


59 


147 


300 


152 


51 


DATES OF THE PUBLICATION OF THE SEVERAL PARTS 


OF THIS VOLUME. 


Part 1.—Containing pages 1 to 58. 


» 2. ” » 59 to 116. 
» Oe » ee Lletomlon: 
pio ” ,, 155 to 196. 
1 De » ,, 197 to 240. 
»» 6. » 241 to 344. 
oye » ,, 8465 to 486. 
» 8. » » 487 to 462. 

9. » » 463 to 546. 


(April, 1883.) 
(July, 1883.) 
(Oct., 1883.) 
(Jan., 1884.) 
(July, 1884.) 
(Jan., 1885.) 
(April, 1885.) 
(July, 1885.) 


(Oct., 1885.) _ 


THE 


SCIENTIFIC PROCEEDINGS 


OF THE 


ROYAL DUBLIN SOCIETY. 


I. —ON SOME EFFECTS PRODUCED BY LANDSLIPS AND 
MOVEMENTS OF THE SOIL-CAP, AND THEIR RE- 
SEMBLANCE TO PHENOMENA WHICH ARE GENE- 
RALLY ATTRIBUTED TO OTHER AGENCIES. By 
PROFESSOR V. BALL, M.A., F.R.S., F.G.8., Hon. Sec., 
Royal Geological Society of Ireland. (Puarte I.) 


[Read, November 20, 1882. ] 


N the year 1878 I published’ a preliminary, and, of necessity, 

imperfect sketch of what, from the evidence then available, 

I believed to be the mode of origin of the series of lakes which 

occur at Naini Tal and its neighbourhood, in the North-west 
Himalayas. 

The probable glacial origin of these unique Himalayan lakes 
had previously been suggested by Mr. H. F. Blanford;? but the 
tentative hypothesis put forward in my Paper was, that they were 
not true rock-basins, but were simply portions of river-eroded 
valleys, which had been more or less dammed up by the fall of 
débris from the slopes of the surrounding hills. So the matter 
was left, but not for very long, as, in 1880 my late colleague, 
Mr. Wm. Theobald,* having visited the lakes, pronounced them 
to be glacial. 


! Records of the Geological Survey of India, vol. xi., p. 174. 
* Proceedings, Asiatic Society of Bengal, January, 1877, p. 3. 
3 Records of the Geological Survey of India, vol. xiii., p. 161. 


SCIEN. PROC., R,D.S.—VOL. IV, PT. I. B 


2 Scientific Proceedings, Royal Dublin Society. 


By a singular coincidence, Mr. Theobald’s Paper, and the first 
news of the,great Naini Tal landslip, reached me at the same time 
when journeying to India in September, 1880. My first formed _ 
intention was, provided permission were obtained, to start for 
Naini Tal immediately on reaching Bombay, as I concluded that 
the phenomena exhibited by this landslip could not fail to throw 
light upon the disputed ‘question as to the origin of the lake. 
T found, however, that a committee had been appointed by the 
Government to report upon the disaster, but that the services of a 
geologist were not considered necessary to take part in the deli- 
berations.! In due time this committee published a report which, 
while dealing with the lamentable destruction of life and pro- 
perty resulting from the landslip, did not throw much light on its 
cause. Fortunately, however, the appearances presented have been 
described by a geologist, Mr. R. D. Oldham,’ who happened to 
be in the neighbourhood at the time. Besides giving a good 
description of the mode of operation of the agencies which cul- 
minate in such landslips, he adds some remarks of considerable 
interest which bear upon my view of the causes to which the lakes 
at Naini Tal and its neighbourhood owe their origin.: 

‘In spite of repeated friendly invitations by Mr. Theobald, that 
I should reply to his Paper, I deferred doing so while still any 
hope remained of my being able to make a further and more 
complete examination of the locality. And now, when all such 
hope is gone, I feel I am not in a position to add much to what 
has been already published; at the same time I have, since I 
visited Naini Tal, examined numerous undoubtedly glaciated. 
lakes in England, Ireland, Scotland, and Switzerland, and I there- 
fore feel increased confidence in suggesting what I believe to be 
the legitimate deductions to be drawn from the whole array of 
observed and recorded phenomena. 


1 By a strange coincidence, the author of an article on landslips, in Nature, dated 
September 30, and which was inspired by the telegraphic tidings of the landslip, 
wrote as follows in reference to the choice of safe ground for building :—“ This is 
mainly a geological question, but it is evidently one of the utmost social importance. 
Among the staff of the Geological Survey of India there is no doubt an officer whose 
services could be made available to examine and report upon the structure of the 
ground with reference to this question.’’ 

* Records of the Geological Survey of India, vol. xiii., p. 277. 


Batt—On some Effects Produced by Landslips. 3 


The illustrations and plans which I now exhibit will serve to 
convey an idea of the principal of these Himalayan lakes (Naini 
Tal) and its surroundings. Tor descriptive details of it and the 
others of the series I must refer to my original Paper. Here it 
will be sufficient, perhaps, to concentrate our attention on Naini 
Tal as typical, though some of the other lakes exhibit individual 
peculiarities indicating local modifications in form, which may 
possibly be connected with the irregular profiles impressed on the 
surface of the rocks at the time of their upheaval, and which are 
therefore less directly due to the effects of subzerial denudation. 
Though often tacitly assumed, it is not, I submit, justifiable to 
conclude that upheavals of mountains left simply plane surfaces for 
the subzerial forces to operate on; ridges and hollows must as- 
suredly have been produced by such disturbances among non- 
homogeneous rocks. 

Naini Tal occupies: the bottom of a valley which runs with the 
strike of a variety of altered rocks, among which much contorted 
and splintered shales are the most prominent: there are also some 
limestones, generally occurring in lenticular bands, and indications 
of the presence of a deep-seated dyke, or dykes, of trap have also 
been observed. 

Where the slopes are gentle the upturned edges of the shales 
are more or less covered by humus, which in many places supports 
good-sized oak and other trees. The ledges which are cut into this 
humus, in order to afford sites for building, serve as collecting- 
grounds for the drainage, and have been the principal cause of the 
disturbance of the equilibrium, which has resulted in the landslip 
about to be described, as well as of many previous ones known to 
have taken place in the same locality. 

The facts connected with the Naini Tal landslip are the follow- 
ing :—On Saturday, the 18th of September, 1880, after about 
forty hours of continuous rainfall, during which time twenty-five 
inches of rain fell, at 10 o’clock in the morning a slip occurred on 
the north-east slope of the valley, which buried a portion of the 
buildings behind the Victoria Hotel, in which there were at the 
time some natives and a Kuropean child. 

_ By the aid of a party of volunteers and some men from the 
military depot, all who had been buried in the ruins, and were 
still alive were rescued: It was then observed that a stream of 

B2 


4 Scientific Proceedings, Royal Dublin Society. 


water threatened the destruction of the hotel, and the labours of 
all who were engaged were directed to the diversion of its course. 
While so engaged, the great slip came down and overwhelmed 
them, raising the total loss of life to about two hundred persons, 
of whom forty-three were Europeans. 

This last fall is believed to have not occupied more than one- 
fourth of a minute in its descent, although several large buildings 
appear to have been carried along on the surface of the debris for 
some distance before they fell. The material of the fall consisted 
of broken, splintery shales, humus, and vegetation, which rested 
upon the upturned edges of a zone of much contorted and shat- 
tered shales. After settling down, the surface of the debris pre- 
sented the following appearance :—It was about 600 yards long, 
of which the lower half dipped at an angle of about 15°, and the 
upper at from 25° up to the vertical. Owing to the immense 
quantity of water which had been absorbed into the mass before it 
began to slide, the whole was in a semi-fluid condition, which was 
testified, not only by the low angle of repose, but also by the fact 
that those who ventured upon it sunk up to the knees. 

One of the principal objections urged by Mr. Theobald to my 
view of the origin of the barrier closing Naini Tal was, that those 
slips “possessed of most mobility, from the greater fluidity of their 
composition, are in the precise ratio of such fluidity, least capable 
of . . . bearing upon their surface craggy masses of rock, such as 
I should term erratics.” 

This almost ex cathedra statement assumes, what is by no means 
necessary, that the blocks should be carried on the surface : and 
it breaks down altogether when compared with the actual fact, 
that this Naini Tal slip; by no means an extensive one, as com- 
pared with many others known to have occurred in the Himalayas, 
did carry down blocks 9 or 10 feet in diameter em the mass of 
detritus not on the surface. Heavy rainfall and streams acting 
on such an accumulation would, undoubtedly, produce an appear- 
ance, by the removal of the finer portions, very closely resembling 
that presented by ordinary moraines, and such an accumulation as . 
that which forms the retaining barrier of Naini Tal. 

It would not be difficult to further illustrate these views by 
reference to several famous landslips which have taken place in 
Switzerland, in which cases large masses of rock, together with 


Batt—On Some Effects Produced by Landships. 5 


finer materials, have been carried down the slopes of mountains, 
and spread far and wide in the valleys at their bases. These 
examples have, however, been fully described elsewhere, so that 
we may, without more explicit reference to them, pass to the 
consideration of another variety of soil-cap movements. 


SuBMERGED ForEsTs. 


To by far the majority of people the appearance of submerged 
forests or bogs in the vicinity of the coast of any land, whether 
continental or insular, would be accepted, without hesitation, as 
being indicative of subsidence. Some observers would probably 
be tempted, moreover, to calculate the amount of the lowering 
from the data so afforded. My present object is to discuss the 
reasons which have led me to adopt the view that such a conclu- 
sion may be wholly erroneous. Nay more, in certain cases, the 
existence of such submerged forests may even afford prima facie 
evidence of upheaval of the land. 

I was first led to the consideration of this subject by the 
existence of apparently very contradictory evidence as to the 
alteration of levels of sea and land in the case of the Andaman 
Islands in the Bay of Bengal. 

When visiting the Andaman Islands in the year 1868, the 
evidence appeared to me to favour the view that the islands were 
slowly rising. Although there were no raised coral reefs then 
known in the islands of this group, there were several creeks 
between the islands which had become more or less unsuitable for 
navigation. Thus the channel between the middle and southern 
islands is said to have been formerly navigable by large boats, 
though now, I believe, small boats can only go through it. Again, 
at the head of Port Blair there is a swampy pass containing man- 
groves through the hilly grounds to the opposite coast, which 
presents the appearance of having, at no very distant period, been 
‘a strait, dividing the South Andaman into two portions. In the 
more southern, but next adjoining group of islands, the Nicobars, 
raised coral reefs are of common occurrence, and their absence 
in the Andamans is certainly remarkable, and not easily to be 
accounted for if the view that the islands have risen be correct. 

The late Mr. S. Kurz contended—from the existence of sub- 
merged portions of forests, and even of buildings which were 


6 Scientific Proceedings, Royal Dublin Society. 


erected during the period of the first settlement of the islands in — 
1796—that they are now in a sinking condition. 

Some of the trunks of trees which he observed had their roots 
attached to the soil, and were still in sitw ; many of them belonged 
to species which do not occur in the outer belt of mangroves, but 
in the next succeeding zone inside it, or in a zone at the foot of 
cliffs, in which positions there is no outer belt of mangrove ewelnps 
owing to the steepness of the shore. 

On the one hand, the fact that the above-mentioned straits have 
become unnavigable may be due to either ordinary or extraordinary 
silting up. By extraordinary, I mean wholesale landslips, such as 
those in Patagonia, and therefore their condition might be coin- 
cident with a general subsidence. On the other hand, mere en- 
croachments of the sea may produce appearances which would be 
mistaken for actual subsidence. ‘This last may be the explanation 
in the case of the above-mentioned buildings, for instance. 

Now, without attempting to discuss the conflicting evidence in 
this particular case, as further examination of the islands, espe- 
cially with reference to the views put forward below, should, I 
think, first be made, I pass to the consideration of the general 
question as to the manner in which such apparently conthieting: 
evidence may be reconciled. 

The subject has already been dealt with ina Paper by Dr. Cop- 
pinger, which was read before the Geological Society of London 
last year.' The phenomena which he describes were observed in 
Western Patagonia, where the soil-cap slides downwards over 
sloping surfaces of rock, carrying with it not only the trees, ferns, 
and mosses on its surface, but also a moraine profonde of rocks, 
stones, and trunks of trees, with which the valleys and lakes 

- become filled up. 

Anticipating that subsidence might be suggested to account 
for some of the phenomena, he points out that the existence of 
raised beaches, and the traces in the rocks of stone-boring mollusca 
above present sea level, prove, on the contrary, that elevation has 
taken place. Removal by water of the lighter portions of the 
material thus brought down leaves a remnant of blocks, which are 
often perched on one another in a similar manner to those which 


* Quarterly Journal of the Geological Society, vol. Xxxvii., 1881, p. 246. 


Batt—On Some Effects Produced by Landslips. if 


have been auneperted by sages: ; and in the particular region in 
question there are such glacial moraines conveniently situated for 
comparison. 

These appearances were contrasted with those of the celebrated 
stone rivers of the Falkland Isles, which Sir Wyville Thompson! 
has attributed to the movements of the soil-cap, which has in part 
derived its motion from the expansion and contraction of the 
spongy mass, due to varying conditions of moisture and compara- 
' tive dryness. 

Several speakers, when discussing Dr. Coppinger’s Paper, 
afforded testimony as to the probability of such a cause being 
capable of explaining many accumulations of blocks and breccias 
in both recent and early times, while Sir John Hawkshaw showed 
that movements of the soil-cap, and with it of rocks, were only 
too familiar to engineers, and that, in some cases, they continued 
for many years after once the surface had been disturbed. 

In this instance of Patagonia, then, we have a beautiful example — 
of the contemporaneity of two apparently contradictory pheno- 
mena—(1) a rising of the general mass of the land; and (2) a sub- 
sidence of the soil-cap. Generalizing from this, it would perhaps 
be not too much to say that, given certain relationships between 
tracts of land and their soil-caps, an upheaval, owing to the dis- 
turbance of equilibrium, would invariably be followed by a subsi- 
dence of the soil-cap. Detrital matter which had settled down at 
its angle of repose must, on the elevation of its sustaining surface, 
find a new position at a lower level, and thus I believe may, in 
some cases, be explained the presence of submerged forests and 
bogs on the one hand, and accumulations of glacial-like debris on 
the other. . 

In regions where there is a heavy rainfall, and also in those 
where the protecting effects of vegetation have been removed by 
the cutting down of forest, subsidences of the soil-cap, as is well 
known, are of common occurrence without any necessary exhibi- 
tion of regular landslips. There are tracts in the Himalayas 
where, at the cost of the primeval forests, tea-gardens have been 
established on the slopes, and where, after a few years, the tea- 


1 Voyage of the Challenger— The Atlantic, vol. ii., p. 245. 


8 Scientific Proceedings, Royal Dublin Society. 


bushes have been left starving on the almost bare rocks owing 
to the subsidence of the soil into the valleys. 

It is far from my intention to make any sweeping, or general 
application of these agencies, to account for accumulations of rocks 
in different geological periods for which a glacial origin is gene- 
‘rally claimed. My object is to draw the attention of geologists to 
them, as their potency is, perhaps, not so fully recognized as it 
should be. 

I do not profess to be an anti-glacialist ; but where so much 
depends upon the fact of glacial epochs having existed during 
different geological periods, it seems to be due to the physicists 
_that geologists should use the very utmost caution in the matter. 

Here I would refer to a case where there appears to me to be 
fairly presumptive evidence of the existence of a glacial epoch at 
so early a geological period as the Cambrian. Recently, at Gair- 
loch, in Rosshire, I exarnined the varied traces of the operations of 
the glacial period in that neighbourhood, and while doing so I 
was impressed with the belief that certain Cambrian breccias lying 
in valleys, scooped out of the surface of the Laurentian rocks, 
afforded evidence from their position, much more than from their 
lithological constitution, of the existence of a glacial period in 
those early times. Modern glacial action appears to have re- 
scooped the valleys which must have already been in existence 
when the breccias were deposited, and therefore it may be argued 
that they were originally carved out by the same tools. This is 
of course not quite conclusive, as it would be if, in support of it, 
glaciated surfaces were found underlying the Cambrians; but 
as yet I am not aware that any such have been discovered at 
Gairloch. 


DESCRIPTION OF PLATE I. 


Naini Tal landslip of the 18th September, 1880, from a photograph. 


eae] 


Il.—ON THE PRESSURE OF EARTH AGAINST A RETAINING 
WALL. By ARTHUR HILL CURTIS, LL.D., D. Sc. 


[Read, June 19, 1882. ] 


WHEN amass of earth is supported by a wall, it is an important 
matter to determine what the stability of the wall should be in 
order that equilibrium should be maintained. 'T’o solve this prob- 
lem, it is necessary to determine the magnitude of the pressure 
and the point of its application. 

. The investigation which determines the magnitude of the pres- 
sure is based on a principle due to Coulomb, in accordance with 
which we suppose that the mass of the earth which presses against 
_ any portion of the wall, measured from the top downwards, seeks 

to lower its centre of gravity by sliding along some plane inclined 
to the horizon, at an angle not less than the angle of friction (or 
repose) of earth on earth, and compute the horizontal force which 
will be sufficient to prevent this tendency taking effect along the 
plane which requires the greatest possible resistance to counteract it. 
The force thus obtained is equal and opposite to the greatest pres- 
sure which can result, and is thus, in one sense, a maximum, but 
yet it is the minimum force which will ensure equilibrium, on the 
supposition that the wall is perfectly rigid. — 

The problem in the case in which the surface of the earth is in 
the form of a cylinder round a horizontal line parallel to the top of 
the wall, which is supposed to present a vertical surface to the 
earth, is solved by a theorem due, I believe, to Dr. Hart, Vice- 
Provost of Trinity College, Dublin: this theorem is as follows :— 

Let a vertical plane OADB (fig. 1) be drawn perpendicular to 
the wall at a point 4, situated on the horizontal line coinciding 
with the top of the wall, and bisecting a unit of its length—one 
foot, suppose: let this plane cut the surface of the earth in the line 
AZDB, and at any point C on OA; let CB be drawn inclined to 
the horizon at the angle ¢, the angle of friction of earth on earth; 
then, if CD be drawn in such a way that, drawing DE perpendi- 
cular to CB, the area CAZD shall be equal to the area CDE, the 


10 Scientific Proceedings, Royal Dublin Society. 


prism whose mean section is CAZD, and whose height is one foot, 
will contain the mass of earth which, by tending to slide (along 
CD), would produce the maxi- 

mum pressure on the portion 

of the wall measured by CA, 

while the horizontal force ne- a 
cessary to prevent this ten- 
dency taking effect is in dbs. 
weight equal to 62:5 p DE’, 
where p denotes the specific 
gravity of earth. It is not pos- 
sible, of course, to apply this 
theorem until the form of the 
line AZDB has been assigned. 

It must here be mentioned, o 
that one of the ablest mathe- Fig. 1. ; 
maticians of our time, himself an engineer, Professor Rankine, has 
taken exception to the assumption that the pressure of earth is 
perpendicular to the supporting wall, and maintains that it is 
inclined to it at a constant acute angle. It may be remarked, how- 
ever, that the force can be supposed to be inclined to the wall at 
an acute angle, only on the supposition that the friction of the 
earth against the wall is taken into account; but, as the mathema- 
tical solution only gives us the least horizontal force consistent 
with equilibrium, and as, in the construction of the wall, it would 
be unsafe to limit-its power of resistence to this minimum value, it 
would not, in practice, be safe to allow, in addition, a margin on 
account of taking into consideration the friction between the earth 
and the wall. 

If, however, Professor Rankine’s hypothesis be assumed, the 
consideration of the problem, when thus modified, leads, in accord- 
ance with Coulomb’s principle, to a theorem differing but little 
from that given by Doctor Hart. 

Let (fig. 2) a vertical plane, perpendicular to the surface of the 
wall—supposed, for greater generality, to be inclined to the ver- 
tical at an angle a—cut the surface of the wall in the straight line 
ACO, and the surface of the earth in the line AZDB; through C, 
any point on the line ACO, draw CF horizontal, CB inclined to CF 
at the angle ¢, the angle of friction of earth on earth, and CDa 


C 


Curtis—Pressure of Earth against a Retaining Wall. Il 


line inclined to the horizon at an angle , greater than ¢; if, then, 
supposing the earth about to slide along DC, we regard the weight 


Fig. 2. 


of the wedge, whose mean vertical section is the area AZDC, and 
whose thickness is one foot, to be supported by the resistance, 
including friction, of the plane whose trace is CD, and of the wall, 
the angle of friction between which and earth is denoted by @; we 
must have equilibrium between the weight of the prism (a vertical 
force, W), the resistence of the plane CD (a force, R, inclined to 
the perpendicular to CD at the angle ¢, or to the vertical at the 
angle 8 — ), and the total resistance of the portion of the wall 
under consideration (a force P, inclined to the horizon at an angle 
a+@); therefore, by the triangle of forces we obtain the equation 


Wee sin ((3 — ¢) : 


P cos (a+@+ 9’ = 6)’ 


or, puttinga+o+¢ =y, 
P sin (6 - ¢) 


or, 


log P = log W + log sin (8 - ¢) — log cos (y - 3). 


12, Scientific Proceedings, Royal Dublin Society. 
Now we must determine 9 so as to make P maximum or dP = 0, 
which gives | 
7 + (cot (B ~ $) ~ tam (y ~ B) dB = 05 
but, denoting CD by’r, we have, ee see 
dW = — IP 5 = dB 
substituting this value for dW, we cieain gp sin (8 —) cos (y - 8B) 


= 7 (00s (B—#) 008 (y-) -sin (8-4) sin (y-) = Weos(y-$), (1) 
gp 5, sin (B ~ $) 00s {(a+ ¢’) - (B-4)} = eos (a+ ¢’), 


or 
gp ;-sin(B - 4) {cos (8 - @) + sin (B - 4) tam(u + 9')} = 


If, then, we suppose CD to be the line which solves the problem, 
W will denote the weight of the cylinder of earth, of length 
one foot, ‘whose mean section is the area AZDC, so that W = — 
go area AZDC; and, if we draw DI perpendicular to CB, and 
DE inclined to DI at the angle a + 9’, the area 


CDE=1 DM.CE=1 DM (CM + HE) 


- © sin (B- 9) r-eos(B- 4) +r sin (B -$) tam (a+ $'); 


therefore area AZDC = area CDE, and therefore the as CD, 
which solves the problem, is such that, drawing D# inclined to 
CB at the complement of the angle a + ¢’, area AZDC = area 
ADE, while 

W sin (B=). 


“aos =O) 
or, by equation (1), 


ger’ sin*({38—) _ gor sin® (B - 9) 


2 cos(y-¢) 2 cos (a+ ¢) 


(r sin (8 - @))? 


ee ’ 
Feo posiaeie)) cos (a + @) 


= 7 cos(a+@) DE 


Curtis—Pressure of Earth against a Retaining Wail. 13 


The case in which the surface of the earth is curved is not 
practically of much importance, but it may be well to consider 
the case in which the surface of the earth, except in the vicinity of 
the wall, is a plane inclined to the horizon at an angle less than 
@, and intersecting the plane of the face of the wall in a horizontal 
line. If the wall be supposed to carry a surcharge of earth, the 
portion adjacent to the wall will weather away, and form a plane, 
AZ (fig. 3), inclined to the horizon at the angle ¢, and therefore 


0) 
Fig. 3. 


parallel to CB. The solution of the problem will be obtained by 
determining, in the trapezium AZBC, the line CD such that, 
drawing DE, inclined to CB at the complement of the angle 
a+, the area CDE shall-be equal to the area CAZD. 

To solve the problem: Suppose it done, and bisect EB in NV; 
then the rectangle CV. Df =2ACDN = trapezium AZBC, and 
therefore known; but as the triangles DBM, DBE, and DBN are 
all known in species, it follows that the ratio of DI: NB is known, 
and from these two conditions it follows that CV. VB is known, 
and the problem is solved by’ cutting CB in the point NV, such 
that CN. NB shall have this known value, taking ENV = VB, and 
7 


making angle CHD = 5 


(a + ¢’): the line CD solves the problem, 


14 Scientific Proceedings, Royal Dublin Society. 


In the case above considered, although as AC varies P con- 
tinues proportional to the square on DE, it is not proportional to 
the square on AC, so that the pressure on the portion of the wall 
measured by AC does not follow the law of fluid pressure, amd 
the determination of the point where P should be applied presents 
considerable difficulty. One subordinate case will be considered 
further on. 

When the surcharge of earth vanishes, the trapezium AZBC 
becomes the triangle ABC (fig. 4). In this case the pressure 


B 


Fig. 4. 
on the portion of the wall measured by AC’ will be obtained by 
drawing a system of lines parallel to those corresponding to the 
line AC; for drawing such, we have 
ACDE CD? ACAD 


ACDE CD? ACAD’ 
or 


AC DE’ ACDE 


ACAD ACAD ~’ 
or 
AC’D'E’ = AC’AD': 
again, 


PVE?) CD Owe 


PP DEF) CD Wiens: 


Curtis—Pressure of Earth against a Retaining Wall. 15 


the magnitude of the pressure for any finite rectangular portion of 
the wall lying between the top and any horizontal line, that through 
C, suppose, varies as the square of AC. The force introduced, 
therefore, by any small given increase in the depth of this hori- 
zontal line varies as AC, its distance from the surface; the force, 
therefore, follows the law of fluid pressure, and the centre of force 
is found by the same law, and therefore is the point S, which 
divides AO, so that AS = 280. 

One case is worthy of consideration, on account of che) sim- 
plicity of the solution—that in which the friction of the earth 
against the wall is neglected, the wall is vertical, and carries a 
‘surcharge of earth, the surface of which, except in the vicinity of 
the wall, is horizontal. 

In this case (fig. 5), if we take CH = CZ, and: erect HD 


Fig. 5. 


perpendicular to CB, the line CD cuts off the area CED = area 
CAZD, and thus solves the problem. To prove this, bisect HB 
in JV, and the problem is then reduced to showing that ACD = + 
trapezium ©.AZB, which can be proved thus :— 

Draw ZQ perpendicular to CB, and produce CA and BZ to 


meet in L; then 
CE? + EB? +2CE. EB = CB = CZ? + ZB°+2LZ.ZB; 
as OH =0Z, EB’ +2CE.EB=ZB°+2LZ. ZB; 


16 Scientific Proceedings, Royal Dublin Society. 


up(22 scx) - z2(25——); 


9 >) 
EB.ON= ZB age 

Gap as 
ON. EB tan¢ = ZB TG 5 sou 
oie De 7 EL 


ao ae trapezium CAZB ; 


ACDN =+4 trapezium CAZB. Q.E.D. 


The magnitude of P in this case can be easily expressed. Let 
CL, AL, and CZ be denoted by H, h, and /, respectively : 


Rs e DE?, but DE = EB tan 9 = (CB - CE) tan 


H H 
-(=,-)) ge a a ee o 


= Hsec ¢-tan $ \/ H? +i? cot? = Hsec o —/ H’ tan’ + 2° 
i pe | H seco -,/ H? tan’ ¢ BP) 


See Moseley’s Engineering, p. 458. 


This expression leads to a construction for the force P, which 
L om a B 


A 


aS 


A 


Fig. Sy 


is useful in determining its point of application as well as its 
magnitude. 


Curtis—Pressure of Harth against a Retaining Wail. 17 


Through C (fig. 6) draw the line CT inclined to the vertical 
line C'A at the angle ¢ ; then 
OT =H sec¢, and AT = (LT? + AL*}* 
| = {BH tan? + )83 
= - (OT - AT)’. 
If, then, we cut off . 
(Wie ES IPO 


so that, if we construct the locus of V, the force on the portion of 
the wall, measured by any line AC, will be obtained by drawing 
through Ca line inclined to the vertical at the angle ¢ to cut the 
locus of V, and the force P will be proportional to the square on 
CV, which may be denoted by z. 
This locus is easily obtained, as follows:—let ZB be axis of Y, 
and LC axis of X; let x and y be the co-ordinates of point V; then - 
QT =< tang = ua, ‘ 
and 
Vey + pe) = AT? = TV? = 2 seco = (lia 
@ —y* — 2yuey =’, 
an equilateral hyperbola whose asymptotes are defined by 
we — yy? — Quay = 0, 
or 


y + tan (Fs % an 
and 
y — tan G-§) z=0 


We are concerned, however, only with the portion of the Hyg 
bola which lies within the trapezium. 

To determine the point of application of the force P, extended 
to the entire height of the wall measured by 40; let O be taken 
for origin, and the axes of X and Y vertical and horizontal ; then, 

if a denote the abscissa of the point of application of P, while x 
represents the abscissa of any point U, and dP the elementary 
pressure on a portion of the wall measured by dz, then affecting 
with a suffix each quantity relating to the point O, P: x, = fadP 


SCIEN. PROC,, R.D.S.—VOL IV. PT. 1. ; ve 


18 Scientific Proceedings, Royal, Dublin Society. 


—-@P—|Pdz- but, at O, «= 0; and, at A, P="0, theretore,) 2 
vanishes at each limit, and .*., as P = gps’, 3:°a, = — f2’dx; but dA, 
the area of UW, any element of the parabola contained between 
the curve, the element dv, and the lines through its extremities 
parallel to s, is equal to — s sin gdz, while ", the ordinate of the 


centre of gravity of this element, = 5 : therefore 


x2, SM @ = — sin df ede = f2adA =2 [adA = 2Az,, 
or 
. 2Az 


2) sin @. 


As a verification of this result, let / vanish ; the hyperbola then 
reduces to its asymptotes; the branch AV becomes the straight 


line through 4, making, with the vertical, the angle : - . (this 


also appears geometrically ; for, if (fig. 7) 


VI - AT, ais DA jn (5-0) 


but 


Curtis—Pressure of Harth against a Retaining Wall. 19 


therefore, 
H,2) sin _ H, 
3s,” sin 3° 


ay as it ought. 

I may remark that Moseley, in his Engineering, has inves- 
tigated, by a different method, the problem where the friction 
between the wall and the earth is neglected, and has deduced, in 
certain cases, analytical expressions for the pressure. ‘These ex- 
pressions may also be deduced from the geometrical solutions 
given in this Paper, but, as they are not logarithmic, they are 
practically, of little value, and, I think, in practice, are of little 
importance compared with graphic methods and geometrical 
constructions. 

It has been objected to such discussions as the above, that, 
after the solution has been obtained on mathematical principles, 
it is necessary to introduce a factor of safety, to ensure stability, 
making the wall from eight to ten times as strong as is in accord- 
ance with the theoretical result ; but this objection is equally valid 
against the application of mathematics to all cases where the 
strength of materials is concerned, in which, as stated by Rankine, 
Twisden, and others, it is usual to take the working stress as one- 
eighth, or one-tenth of the proof stress, which is itself considerably. 
short of the ultimate strength. If a wall could be made perfectly 
rigid, and would not in time become weakened if taxed to its ulti- 
mate strength, then the mathematical deductions would in practice 
be exact. 


C2 


20a 


III.—ON GEARING FOR BICYCLES AND TRICYCLES. By 
GEORGE JOHNSTONE STONEY, D.&c., F.R.S., ann 
GEORGE GERALD STONEY. , 


[Read, December 18, 1882. ] 


Tux making of Bicycles and Tricycles has become an enormous 
industry, and the pecuniary value of patents affecting paltry 
details, if they can be brought largely into use, is consequently 
great. The bicycle industry is so overloaded with patents of this © 
kind that no purchaser can obtain a machine with every improve- 
ment which: he may reasonably desire, and the best makers are 
very much hampered. The inconvenience to the public in this 
case, which accompanies benefit to a few, has suggested to us that 
it may be of advantage to communicate the three following con- 
trivances to the Royal Dublin Society, with a view to rendering 
them incapable of being made the subjects of patents. 

We have been impressed very much with the advantage of a 
small wheelin mountain rides, which are those which we chiefly 
practise. But on the other hand, when one comes down into the 
plain, the small wheel becomes unsatisfactory, as it prevents the 
rider attaining the speed which would otherwise be his natural 
‘pace under those easier circumstances. We have hitherto ridden 
machines of a size selected with a view to strike a compromise 
between these opposed requirements, but a much better result 
would be obtained if we could get a wheel which would become 
small and powerful on the hills, and large and swift in the level 
country. A wheel which could be geared to two or more speeds 
presents the same advantages. And there are two ways in which | 
we should propose to accomplish this. In both we should prefer a 
very small wheel, say of 86, or at most 40 inches diameter, to be - 
driven level, as the technical phrase is, that is, ungeared when 
climbing up hills, and to be geared up so as to furnish a higher 
speed on easy ground. 

I. The first of these contrivances is bate to a machine with 
some such levers as the ‘Xtraordinary’ and the ‘Facile.’ The 

hub of the bicycle wheel is to be made tubular, for the purpose of 


Sronny—On Gearing for: Bicycles and Tricycles. 21 


allowing an inner axle, to which the cranks are keyed, to run - 
freely within it. T'o one side of the hub a sun-wheel is fixed, into 
which a planet-wheel, mounted on a pin near the end of one of 
the cranks, is to work. If this planet-wheel be fastened to the 
crank so as to form one solid piece with it, the machine will 
be geared level in the way that is suited to hill-work. In this case: 
the wheel of the machine, with its sun-wheel attached, the crank 
and the planet-wheel will all form one solid mass, which will turn 
together without any relative movement. On the other hand, if 
the planet-wheel is fastened to the lever or connecting-rod of the 
bicycle, it will continue to be carried round by the crank, but will 
be kept from turning round with it, and accordingly it will drive 
the sun-wheel at a speed which is determined by the numbers of 
teeth in the sun and planet-wheels, and which can be made what- 
ever the maker pleases. A proper appliance should be provided, 
which will enable the rider at will to connect the planet-wheel 
either to the crank or the lever, and he can thus drive his machine 
level when he connects the planet-wheel with the crank, or geared: 
up when he connects it with the lever. . 
_ II. The next contrivance is one for attaining the same end, 
and is suited to machines with levers something like those of the 
‘Facile... Cogged wheels are to be keyed on both ends of the axle 
of the bicycle wheel; each of these is to work into a cogged wheel 
placed immediatély above it, and running on a pin screwed firmly 
into the fork of the bicycle. Hach of these cogged wheels is to be 
provided with a pin projecting from its face, over either of which 
the connecting-rod from the lever may be hooked. Ii the connect- 
ing-rod is hooked to the lower wheel it will drive the machine ‘ level,’ 
and the upper cogged wheel will run as an idle wheel, doing no 
service, but doing no harm. If, on the other hand, the rider hooks 
the connecting-rod to the upper cogged wheel, his foot will drive 
that cogged wheel, which in turn will drive the lower one, and 
with it the bicycle wheel to which it is attached. The number of 
teeth in the wheels will of course then determine the speed. 

It would be a great convenience if the rider could alter the 
gearing without dismounting; and this might be effected if con- 
necting-rods hung permanently from both the wheels, with a cross- 
rod joining their lower ends. This cross-rod should pass through 
an eye attached to the lever on which the foot works, and should 


22 Scientific Proceedings, Royal Dublin Society. 


be capable of slipping from end to end through that eye, and of 
being held to that eye in either of these two positions. When the 
-cross-rod is slipped to one end of its range the foot would work the 
lower of the cogged wheels, and would drive the machine level, 
and when the rod is slipped to the other end the foot would work 
the other cogged wheel, and would drive the machine ‘geared up.’ - 
The slipping of the cross-rod could be effected by continuing the 
longer of the connecting-rods upwards so as to bring it within 
reach of the rider, and by providing spring-clutches to hold the 
cross-rod in its place when it has been slipped to either end. , 
The third: contrivance is one which we described at a former 
meeting of this Society, and which we would ask leave to describe 
again with a view to its being placed on record. It isa contrivance | 
for applying balance gear to a cranked axle. Balance gear—that 
is, gearing which allows the driving wheels of a tricycle, traction- - 
engine, &c., to travel at unequal velocities while both continue to 
be driven—has hitherto been applied to a straight axle lying be- 
tween those wheels. We wish to point out that it may be applied 
to a cranked axle, so that it is possible to apply it to a tricycle, : . 
the main axle of which is to be acted on directly by the feet—an 
arrangement which we believe would in many cases be preferable 
to the method hitherto employed of adding a countershait for the 
feet to work on. This we propose to do as follows:—The cogged 


SN 


Tn Tm 


_ 


Mu 


wheel a is keyed to the axle of one of the driving wheels of the 
tricycle. a acts on } and 0’, cogged wheels keyed to an axle pass- 
ing through a tube on which the right foot acts. 0’ acts on ¢, ¢ on 
d, done and e’, keyed to an axle passing through a tube on which 


Stonsy—On Gearing for Bicycles and Tricycles. 23 


the left foot acts, and finally e’ on /, which is keyed to the axle of 
the second driving wheel of the machine. The intermediate 
wheels ¢ and d are introduced only to make the arrangement more 
compact. If abundant space can be allowed, these intermediate 
wheels may be dispensed with by making 0’ and e large enough to 
act directly on one another. 

The balance gear here described might, perhaps, sometimes 
with advantage, be applied to the countershaft of the machines 
which are provided with a countershaft. 

Tn all cases where balance gear is employed, we wish to point 


IP ie, Ye 


out that the machine may be guided by adequate breaks which 
may be applied to one or other of the driving wheels at will. We 
have found wood a good material for powerful breaks which are to 
act upon the rubber of a wheel. 


24 . Scientific Proceedings, Royal Dublin Society. 


A machine provided with the balance gear and guiding arrange- 
ments we propose might have the rider’s weight brought almost 
entirely over the driving wheels, in which case his position might 
be made secure by two safety-wheels mounted like castors, one in 
front of one driving wheel, the other behind the second driving 
wheel. Or perhaps better still, the lever which applies the break 
might; be made to act on connecting bars which would at the 
same time give the proper. inclinations to the two safety-wheels. 
One arrangement for accomplishishing this is represented 1 in the 
adjoining figure. It would, as in Blood’s patent, give a greater 
inclination to the wheel travelling on the inside of the curve along 
which it is desired to travel so as to secure continuous rolling. In 
the figure, O is a fixed centre round which the system of connecting- 
rods is made to turn, and there are pivots at a, b,c, d: ma and nd 
are projections rigidly connected with the wheels to be guided, as 
in the guiding apparatus of the ‘ Coventry’ tricycle. 

A tetracycle built in this way would make only two tracks on 
the road, which is a great convenience. We may observe that we 
have not found a high position for the rider to be a source of 
danger; while it gives an advantage in touring, and looks better. 


Lele 


IV.—VELOCITY AND ENERGY OF SMALL SHOT. Br JOHN 
RIGBY; M.A. 


[ Read, February 19, 1883. | 


THE Velocity of projectiles, and the laws which govern the re- 
sistance of the air, have been investigated by various methods. — 
Robins, in 1742; and Hutton, in 1790, with the aid of the ballistic 
pendulum, made considerable progress in determining them in the 
case of spherical balls of moderate size. Between 1839 and 1848 
experiments with larger spherical shot were made at Metz, by 
Piobert, Morin, and Didion. The introduction of electrical appa- 
ratus for measuring short periods of time gave a fresh impulse to 
these researches, and since 1860 a vast amount of work has been 
done by British artillerists in this direction. The development 
of rifled ordnance and elongated shot enlarged the scope of the 
inquiry. In 1865 the Rev. Francis Bashforth, then Professor of 
Mathematics to the Advanced Class of Artillery Officers, constructed 
a chronograph, which bears his name, and gave satisfactory records 
of the successive periods occupied by rifled projectiles in passing 
the intervals between ten screens, placed at distances from each other 
of 150 feet.1 With rare industry Mr. Bashforth has reduced and 
tabulated the results of experiments extending over sixteen years, 
and his Tables of Coefficients render it possible to calculate the 
trajectories, remaining velocities, and times of flight of projectiles 
of most of the various forms and dimensions likely to occur in 
-practice. The Tables for computing the remaining velocities, &c., 
of Ogival-headed shot embrace all initial velocities from 100 to 
2900 feet per second.’ Those for spherical shot range from 500 
to 1900 feet per second. eens ) 

. It is unfortunate that no law can be found to express the resist- 
ance of the air to a projectile in terms of the velocity. For Ogival- 
headed elongated shot it is stated by Bashforth to vary roughly 


1-Vide A Mathematical Treatise on the Motion of Projectiles. By Francis Bash- 
forth, B.p., &e. Asher & Lee, 1873. 

? Vide Final Report of Experiments with the Bashforth Chronograph. W. Clowes 
& Son, 1880, 


2m Scientific Proceedings, Royal Dublin Society. ) 


as the sixth! power of the velocity when this lies between 900 and — 
1100 f.s.; to vary as the third power from 1100 to 13850 f.s. ; 
and for celouities above 1350, to vary as the second power, which 
is the Newtonian law, based on the supposition that the shot is at 
every moment penetrating an undisturbed medium, a supposition 
which only holds for velocities greater than the velocity of sound. 
This remarkable change in the law of resistance, when the ve- 
locity passes a certain limit, was early discovered by Robins and 
Hutton. Under these circumstances Mr. Bashforth has chosen to 
express the resistance of the air by the help of a variable coefficient 
and the third power of the velocity; and as it has been found that 
the effect of the resistance at a uniform velocity varies as the 
square of the diameter divided by the weight, it is easy to apply 
the Tables to shot of various dimensions by substituting the parti- 


b) 
~ 


a 
cular value of in each ease. 


As the experiments with the Bashforth Chronograph were 
carried out with guns varying from 3 inches to 9 inches diameter, 
and with shot varying from 6 lbs. to 250 lbs. weight, their appli- 

cation to small. arms must be taken as an approximation only, 
since there are in the latter case modifying conditions, the effects 
of which cannot be predicted. 

In the case of spherical shot, however, as omnOnmnents made 
with musket bullets have been found to give results which apply 
to large guns, it is fair to conclude that the Tables calculated from 
the latter may, with sufficient truth, be applied to spherical projec- 
tiles of diameters much smaller than musket balls, such as the 
small shot used in fowling-pieces; and it is more particularly to 
the movement of such small open es) that L wish to direct 
attention. 

In 1878, Mr. J. H. Walsh, the ingenious editor of the Meld 
newspaper, dissatisfied with the tests then in use, devised a kind of 
recoiling target, which he named a “ force gauge,” for the purpose 
of measuring the force with which the pellets in a charge of shot 
struck the mark at a certain distance. Up to that time very vague 
ideas were held as to the actual velocity of the charge propelled 
from shot guns. One writer in the Meld placed it as low as 


1 This statement is modified subsequently. See Final Report, p. 4. 


Riespy—On the Velocity and Energy of Small Shot. — 27 


550 feet per second, while an expert, who had published several 
books on guns, affirmed that the mean velocity of the charge in 
the first 40 yards was 1200 feet per second. ; 

In this state of the question I determined to measure, by means 
of the “ Boulengé” chronograph, the actual time of flight for 120 
feet from muzzle. To enable me to do so, one of those instruments 
was placed at my disposal by Messrs. Pigou, Wilks, and Lawrence, 
the eminent gunpowder manufacturers at Dartford, and I found 
their apparatus quite suited to the purpose. The interval was 
measured between the rupture of a fine wire stretched across the 
muzzle, and the movement of an iron target hung on an axis, in 
- such a manner that the impact. of a considerable portion of the 
charge was necessary to effect the interruption of contact. In this 
way the velocity of the average pellet in the charge was more 
nearly approached than if the second interruption had been made 
by a single pellet, which might have a velocity considerably above 
the average of the whole charge. 

_ Since this Paper was commenced a communication has appeared 
in the Meld. from the pen of Major M‘Clintock, giving results 
of numerous experiments made at the Enfield factory on the velo- 
city of small shot. 

Major M‘Clintock has also used the Boulengé chronograph, 
but has rendered his results less satisfactory by employing as his 
second screen the frame with wires stretched over it, which is 
commonly used when the velocities of rifle bullets are investigated. 
He confesses that his results are affected by this obvious error, and 
that it is a matter of chance altogether whether the current at the 
second screen is interrupted by the quickest or by the slowest pellet 
in the charge. 

The series of shots fired by me at Dartford gave the velocities 
in the following Table as those of the respective charges of shot at 
sixty feet from the muzzle. I am entitled to state this, because, 
although the chronograph only gives the time taken by the shot to 
traverse the observed interval, it has been shown that if the resist- 
ence of the air varies as V°, the velocity at: the middle point of a 
short range is denoted by dividing the range in feet by the time 
in seconds. 

As therefore it has been proved experimentally that the resist- 
ance does vary approximately as the cube of the velocity, I am 


28 Scientific Proceedings, Royal Dublin Society. 


justified in accepting the mean velocity in the range of 120 feet to 
be the actual velocity at 60 feet from muzzle. 


Ve ELOCITIES at 60 feet from Muzzle of various Charges of Shot, 
observed May 6th and 12th, 1879. 


[The figures are the averages of four shots in each case. ] 


eaee of Powder. | Shot. May 6. May 12. Remarks. 
Drams, |Sizeofgrain.| Oz. No. | Ft. per second.| Ft. per second. ecaeatier 
12 OU INO; 14 palatal gel NG 847 861 30 in. 
6 ot a 14 45 — 839 ’ 99 
99 34 as 1 sh — 850 i 
99 3t os 1 Hs — 838 99 
a6 3 BS 17 Ban | 834 — 9 
99 3 } NOs SB. |} le op 827 — 39 
59 3+ Rene 12 4 | — 864 5 
90 3+ ss 14 8 — 761 99 
6 24 43 1 6 _ 812 — a 
99 24 a 13 6 750 — 3 
20 24 at qt 6 — 828 9 
35 2 5 5 39 = 7384 99 
59 24 6 1 6 768 — 28 in 
bo 2 is 1 a 711 — 5 


From these velocities can be calculated by Bashforth’s Tables © 
what are the muzzle velocities and the final velocities at 120 feet, 
180 feet, &e. For this purpose, however, it is necessary to deter- 
mine the diameter and weight of the individual pellet whose move- 
ment one wishes to examine, and also to assume that on leaving the 
muzzle it is cireumstanced, as to the resistance of the air, as if it 
were the only one in the charge, and also spherical. In practice 
the resistance to each pellet near the muzzle is modified by the 
contiguity of others, whereby the sum of all the resistances is re- 
duced; but as want of true sphericity would increase, the effect of — 


| Riepy—On the Bey and Energy of Sea Shot. 29 


air resistance, these sources of error may balance one another to a 
considerable degree. 

‘The measurement of the diameter and weight of small shot of 
various sizes, which are designated by the trade numbers of 1, 2, 
3, 4, &e., is rendered troublesome by the fact that the Bee 
makers seem to have selected their size at random, and no two 
makers agree as to the exact weight of pellet to which they give 
any particular number. In America, the firm of Tatham and 
Brothers has adopted a more satisfactory plan, and instituted an 
“American Standard.” ‘They take the diameter of their largest 
dropshot as °23 of an inch, which gives twenty-four pellets to the 
ounce, and manufacture twenty-one sizes, each successive number 
being 01 less in diameter than the preceding, until their fine dust- 
shot is reached, at a diameter of ‘03; in addition to which, they . 
make an extra-fine size, with dsaaneter of -015, and weight of 
84020 to the ounce. For convenience of computation, I have taken 
three of their sizes, V1Z. :— 


No. 1, diameter 16, weight a 


OZ. 
ISOs % ss LO 301° 
1 oz. 
No. 9, 5 08, > Fag: 


These Li the first, heavy shot used for wild-fowl ; the — 
second, the shot in most general use, and called No. 6 by Thy eh 
_. makers; and the third, snipe-shot (Nos. 8 or 9, English). 


respectively, 


al? 
No. 1, 29°08. No. 7, 46°56. No. 9, 58°16. | 

If I now select from the observed: velocities of the medium- 
sized shot at 60 feet, 840 f. s., as a representative one for the 
ordinary charge of a good gun, and calculate by the Tables the 
remaining velocities at intervals of 60 feet, we get the following :— 


American No. 7 shot, 291 to the oz. . . W=-000215. 
Velocity at muzzle, § 1270 fs. Energy. 
50 yards 8 40pe 2-36 Ibs. 
0 4) Got, USE og 


i BOM ie O09 ae O66, 3, 


30° . Scientific Proceedings, Royal Dublin Society. 


Now, assuming that equal weights of shot of different sizes 
acquire the same muzzle velocities, we get’ for— 


Divo ehor Ul toeiees, © 0. Was 000eam 
Velocity at muzzle, 1270 f. s. Energy. 
% 20 vente 956, 12.49 lbs. 

5 ate A0 Te. GG, Bass 8:24, 

: 60 654 ,, O84 ,, 

” 80, 065 ,, 4°39, 

3 1 3 90 9 529 9 3°82 ” 

Rane ail OO} saute 497, Bre op 

Again, for— | 

No. 9 shot, 568 to the oz, . . W=-000011. 
Velocity at muzzle, 1270 f.s. Hnergy. 
i 20 yards, PRK Ritch 1:03 lbs. 

Ue Ae ae 565, ‘545. ,, 

: 45 ,, o29)),, Ae. Lou 

” 50 ” 497 ” "422 ” 


The computed velocity here obtained for No. 9 at 20 yards is - 
-16 f£. s. in excess of the velocity at that distance of the smallest size 
English shot used in my experiments. This is probably due to the 
smaller shot encountering more friction in its passage through the. 
barrel, and so losing muzzle velocity. We may conclude, there- 
fore, that the results obtained above for various-sized shots rather 
under-estimate the differences of velocity between equal weights of 
large and small shot propelled by same charge of powder. 

The velocity of 634 f.s., at 40 yards for No. 7, was found to. 
agree closely with the results of a calculation made from the 
observed. motion of the Field Force Gauge when struck by the shot 
at that distance. 

From an examination of the remaining velocities and energies 
in these Tables, the great advantage of using heavy shot for long 
range is very apparent. Starting at 1270 f.s., the No. 7 shot has 
at 40 yards lost half its speed, and at 60 is reduced to 2ths. The 
No. 1 retains half to nearly 60 yards, and 2ths to nearly 100 yards. 
The No. 9, on the other hand, is reduced to half at 32 yards, and 
to 2ths at about 48 yards. The contrast between the energies 


Riepy—On the Velocity and Energy of Small Shot. bl 


remaining at 40 yards is still stronger, No. 1 having at that dis- 
_ tance seven times the energy of No. 7, and fifteen times the energy — 
of No.9. And, again, the energy of a pellet of No. 1 at 100 yards © 
is equal to that of one of No. 7 at 10 yards from the muzzle. 

This consideration of the action of single pellets must not, how- 
ever, be taken as proof that the killing power of equal charges of 
these different sizes of shot varies in the same proportion as these 
energies. ‘hat might obtain if the game were struck by an equal 
number of pellets in each case; but, in fact, the number striking at 
a given distance is proportional to the number in the whole charge, 
and is in inverse proportion to the weight of each pellet. 
To illustrate this, take the extreme sizes, No. 1 and No. 9, in 
which the diameters are as 2 to 1, and the weight as 8 to 1. At 
20 yards the energies of the individual pellets are as 12°49 lbs. to 
1-03—say as 12 to 1—but the number of pellets in the charge of 
No. 9 being eight times greater than that in the charge of No. 1, 
for each pellet of the latter eight of the former will strike a given 
area, and the total energy expended on it is as 12°49 to 8-24, or as 
3 to 2 only. At 40 yards, however, the pellet energies are as 8:24 
to -645—say 15 to 1—and the total striking energies on a given 
surface as 8:24 to 4:36—say as 2to 1. We see, then, how pro- 
nounced is the advantage of large shot at the longer ranges. 

To estimate the efficiency of different sizes of shot in practice is 
a more complicated question than this, because the shock of a 
number of blows delivered at the same time is found to disable 
birds more suddenly than their complete perforation by one or two 
pellets, which may leave the wing-power still active for a consi- 
derable period. The necessary penetration is also a very important — 
condition, as it must be sufficient to carry the pellet through the 
external defences of life, the feathers, flesh, &c. Penetration does 
not march with energy, because resistance to it increases as the 
square of the diameter of the pellets; and, consequently, in com- 
paring the penetration of pellets of different sizes striking with the 
same velocity, their penetration may be roughly estimated to vary 
‘simply as their diameters. It will thus be seen that the penetration 
of No. 1 is only double that of No.9 at those distances where they 
have equal velocity, although their energies are as 8 tol. It is 
probable also that the resistarice of flesh, &c., to the penetration of 
projectiles varies as a high power of the velocity. There are no 


o2 Scientific Proceedings, Royal Dublin Society. 


experiments to determine what this is, those hitherto made with 


ordnance being directed to the law of penetration in such substances _ 


as wood, brick, sand, clay, &c. The remarkable effects produced 
_by firing rifle bullets into soft, inelastic substances, prove that the 
resistance increases as a high power of the velocity, the penetration 
diminishing when a certain limit of speed is exceeded. — 

The relative velocities of small shot, and of the birds and 
animals against which it is used, is beyond the scope of this Paper ; 
but it will be seen that the time of flight of medium shot being 1th 
of a second for. 40 yards, a very large allowance must be made in 
many instances to ensure striking: In the case of a driven bird 
crossing at that distance-at a rate of 60 miles an hour (a high, but 
possible speed), the allowance for the motion of bird should be about . 
15 feet, as it will move 124 feet in +th of a second, and the time 
oceupied in the act of firing the gun, and the passage of the shot 
from breech to muzzle, must be also allowed for. It will be seen, 
therefore, how difficult it is to attain anything like certainty in 
stopping birds flying at high speeds across or overhead. 

Before concluding, I would direct attention to the magnitude 
of the. resistances developed in the air by high velocities. The 
resistance to a spherical shot 15 inches in diameter, moving at a rate 
of 2100 f.s., is G42 lbs. A flat surface of equal diameter would 
experience a higher resistance. Again, the same shot started at a — 
speed of only 1700 f. s. loses, from the resistance of the air alone, 
in the first 100 feet of its flight, and in less than the ;5,th part of 

a second, 75 foot tons of energy. 
; It appears to follow from these facts, that whenever it is sought 
to obtain motion by using the resistance of the air, the efforts of 
inventors should be directed to giving a maximum speed to their 
machines, rather than an extended surface. It is probable that if 
the problem of driving zerial machines be ever practically solved, it 
will be by attaining high speed in the propellers, and thus utilizing 
the enormous resistance which the air offers to bodies moving 
through it at high velocities. 


pesee] 


V.—ON RECENT ADDITIONS TO OUR KNOWLEDGE OF THE 
GOLD-BEARING ROCKS OF SOUTHERN INDIA. By V. 
BALL, M.A., F.R.S., F.G.S., Professor of Geology and Minera- 
logy in the University of Dublin. 


[Read, February 19, 1883. ] 


THREE years ago, when I read before this Society an account of the 
“¢ Mode of Occurrence and Distribution of Gold in India,” I pointed 
out that the available information as to the geology of some of the 
regions which were then attracting the notice of gold mining com- 
panies was very imperfect. . 

Recently this deficiency has to a considerable extent been: 
removed by the publication of a Paper by Mr. R. B. Foote, of the 
Geological Survey of India,! in which he has suggested the exist- 
ence of a correlation between the gold-bearing rocks now known 
to exist at the several localities where mining operations have com- 
menced, and at some others where Hae occurrence of auriferous 
sands has been ascertained. 

The subject, as I propose to treat it, deals especially with the 
geological aspect ; but since so large an amount of capital—upwards 
of £3,000,000—has been invested in companies, it is natural that 
a great number of people should regard with particular interest 
the economic side of the question; for this reason, therefore, I 
think it desirable that I should make some preliminary remarks 
on the productiveness of Indian mines. 

In the absence of detailed and thoroughly trustworthy accounts 
of operations at particular mines, it is necessary to be somewhat 
general in our statements, and yet this is a subject by no means 
well suited for such a method of treatment. ie 

About a year ago I was challenged publicly at a baecine in 
London to state at what depth the quartz reefs would be most 


1 Notes on a Traverse across some Gold-fields of Mysore, Records of the Geolo- 


gical Survey of India, vol. xv., 1882, p. 191. 


SCIEN. PROC., R.D.S.—VOL. LY. PT. I. D 


34 Scientific Proceedings, Royal Dublin Society. 


auriferous, and privately I have been interrogated to the same 
effect. The supposition that at a given depth gold would be 
found in comparatively great abundance is one that has received 
some currency from the fact that certain reefs in Australia have 
been worked with most profit at great depths. It is a supposition 
which has proved very convenient for those companies which are as 
yet unable to show any returns to shareholders for the large sums 
of money which have been expended. 

Now, if we attempt to apply such an hypothesis to the Re 
in question, we find ourselves at once landed in a maze of absur- 
dities. The only meaning that“ depth” can have in this connexion 
is the vertical distance downwards from the surface, which latter is, 
in this particular case, a most variable datum, varying in level not 
only by hundreds, but even by thousands of feet, since some of 
the reefs are believed to be traceable from high elevations on the 
Wynand plateau, 3000 feet above the sea, downwards to the low- 
lying tracts at its foot. These differences in contour being mainly 
due to subeerial denudation, it stands to reason that a depth of, say 
200 fathoms, on a reef referred to the sea-level standard, is a very 
different thing when applied to.a mine on the top of a lofty plateau — 
to what it is when a mine at its foot is in question. 

Each mine, therefore, can only be discussed on its own merits, 
and the outcome of all that has been done in the exploitation of 
gold-bearing reefs may be expressed by a truism which carries 
with it no hypothesis. It is simply this—that the richest part of a 
reef is that which, when experimentally tried, contains most gold. 
Similarly situated and neighbouring reefs may be found to exhibit 
similar phenomena ; but to expect reefs situated at great distances 
from one another, and at varied altitudes above sea level, to exhibit 
any close resemblance in their characters, when mined to the deep, 
is a manifest absurdity. 

Of the wide-spread distribution of auriferous rocks in certain 
parts of India there can be no doubt; and it is strange that we should 
not yet, after three years, be in possession of more positive evidence 


_ of their productiveness. Highteen months ago I heard of cases of 


managers of mines being pressed by their London directors to 
push their works onwards to the deep, the natural conclusion being 


* King, Records of the Geological Survey of India, vol. yiii., 1875, p. 36. 


Batt—On the Gold-bearing Rocks of Southern India. 35 


that the reefs near the surface had not proved rich enough to work ; 

so that hopes for the future depended on a hypothesis as to their 
improvement to the deep, which had no real justification in fact. 
Indeed, I might add to this that in some instances these operations 
were, I believe, carried on where there was no true reef exposed at 
the surface. 

I have carefully watched for consistent evidence of any of 
the mines proving productive to a profitable extent. There is 
no d@ priori reason against the capability of some of them be- 
coming so; but rather the contrary. Still shareholders of the 
companies, with scarce.an exception, are now complaining that 
there are no results to justify the confidence which they have 
shown in the hopes held out to them of returns at dates now 
long past. 

I take this opportunity of referring to a large volume 
which has recently been published. The author, when noticing 
my writings on this subject, though commending my caution, 
describes me as being a pessimist, and thereupon complacently 
incorporates into his book, without the use of inverted commas, 
nearly forty large pages of facts which I had most laboriously 
collected for my chapter on Gold in the Economic Geology of 
India. 

The term pessimist when thus used must be intended to indi- 
cate a person who bases his opinion on well ascertained facts—and 
on them alone—and who rejects, as unsuited to his purpose, the 
high-flown and always sanguine views of writers whose language 
sometimes keeps pace with their interests. Such, at least, was my 
professed method; and it may even prove that the opinion I 
expressed, guarded as it was, was only too favourable. I certainly 
believed that long ere this there would have been, in the cases of 
‘some of the companies, more tangible results than I have yet been 
able to hear of. : 

_ Mr. Foote has ascertained that, traversing the granitic gneissose 
rocks, which form the uplands of Mysore, there are several parallel 
zones of schistose rocks in which all the principal known gold-bear- 
ing localities are situated. Two of these zones are traceable for 
several hundreds of miles, and their width is in one locality, at 
least, eighteen miles. Although the nature of the relations 


D2 


36 Scientific Proceedings, Royal Dublin Society. 


eixsting between these zones and the neighbouring rocks do not 
appear to have been as yet very fully elucidated; still, in general 
terms, they may be described as being formed of schists which 
rest in synclinal troughs upon the older granitic gneissose rocks. 
The schists are of various kinds—hornblendic, chloritic, he- 
matitic and micaceous, the latter passing into quartzites, and in 
one of the zones there is a very remarkable and interesting bed 
consisting of an enormously thick conglomerate of pebbles and 
boulders of compact gneiss in a greenish-grey foliated chloritic 
matrix. Traversing these schists, &c., occur quartz reefs, in 
which traces of gold are found, and with the presence of which 
the existence of the auriferous deposits generally appear to be 
connected. 

At one locality, near Honnali in Mysore, there are a great 
number of reefs traversing chloritic rocks. ‘To them is traceable 
the source of the gold which is found distributed through the red 
soil, covering the neighbouring low country. Mr. Foote describes 
having witnessed the prospecting of some of these reefs by an 
experienced Californian miner, the results having been satisfac- 
tory. The quartz was found to contain gold, which was visible in 
grains and scales, scattered pretty freely through the mass. The — 
“Turnbull” reef, which was the most promising of the group, 
could be traced, with some breaks, for a distance of nearly six 
miles. “The results of many washings, both of crushed quartz 
and of the red soil taken from many localities and various levels,” 
were in the majority of instances “satisfactory.” Significantly 
it is remarked, that the prospects in this case are certainly greater 
than those of other companies whose shares are, or were till lately, 
favourably quoted. 

Regarding the Kolar field, Mr. Foote considers that the reefs 
found there, though small and inconspicuous at the surface, are 
true fissure veins or lodes. The quartz composing them is, he writes, 
“a bluish or greyish-black diaphanous or semi-diaphanous rock 
which is remarkably free from sulphides (pyrites, galena, &c.) of 
any kind. The gold found is very pure and of good colour. Several 
washings of crushed vein stuff were made in my presence at the 
Urigam and Kolar mines with really satisfactory results, the quan- 
tity of gold being very appreciable.”’ The samples, it is said, were 


Batt—On the Gold-bearing Rocks of Southern India. 3” 


not picked ones, by which it is to be presumed that we are to 
understand that they were not exclusively. from the casing walls of 
the reef or from the feeders. | : 

One report which I received from this locality was, however, 
that the thin casing walls of the reefs and the feeders or leaders 
from them, alone contained gold in paying quantities, the bulk of 
the reefs not containing gold sufficient to pay the cost of extraction. 
Similar observations have been made by Mr. King with reference 
to some of the Wynand reefs. Where such is the case the matter ' 
narrows itself into a purely mining question, whether in following 
to the deep and extracting these casing walls the expense of deal- 
ing with a comparatively large proportion of practically barren 
rock will not exceed the produce from the paying portion. The 
feeders, in the majority of cases, are probably of too limited 
and capricious a distribution to admit of being mined to any 
extent. 

It is, to the best of my belief, fully two years since some of 
the engines and stamps were set up at Kolar, so that shareholders 
cannot be accused of undue impatience if they now ask for re- 
sults. 

Regarding the geological age of these gold-bearing rocks, it 
seems probable that they belong to the lower transition or sub- 
metamorphic series of India, the representatives of which, as I 

showed in my previous Paper, are also auriferous in Bengal. 

In lithological characters, especially in the prevalence of chlo- 
ritic schists, there is a very close resemblance. Invariably I found 
in Bengal that chloritic schists, traversed by quartz reefs, were to 
be found in the vicinity of those tracts where the auriferous sands 
were richest. The coincidence was far too constant to have been 
accidental. | 

I cannot but believe that there are localities in India where 
gold, in paying quantities, exists. A. failure upon the part of 
a number of the companies to produce profitable results would 
not necessarily invalidate this opinion. Some have acquired pro- 
perties which are, probably, worthless, while others have a heavy 
burden of capital which may prove most detrimental to their pros- 
perity; but the most competent men who have examined the pro- 
perties are unanimous in asserting that some of the mines are of | 
promise. . ; 


38 Scientific Proceedings, Royal Dublin Society. 


A large measure of success would be of enormous importance 
to India, as the production of gold there would tend to reduce the 
rate of exchange which at present causes so much loss to the public 
and to private purses. At the same time, to be appreciably felt the 
outturn should amount to several millions sterling, otherwise it 
would not influence the enormous transactions between India and 
Europe: these at present are the cause of a process of depletion 
which is most detrimental to the best interests of the former coun- 
try, while it does no good whatever to the latter. 


ree?” 


VI—ON THE POSSIBILITY OF GOLD BEING FOUND IN 
QUANTITY IN THE CO. WICKLOW. By GEORGE HENRY 
KINAHAN, M.R.I.A., &c. 


[Read, February 19, 1883. ] 


In a Paper read some little time since before the Society, “‘ On the 
Mode of Occurrence and Winning of Gold in Iveland,”!-the writer 
gives a very exhaustive account of the Wicklow Placer mines, 
while since then our Honorary Secretary, in his admirable report 
on the Economic Geology of India,’ seems to suggest “that very 
little more gold is to be found in the Gold-mine Valley”; and the 
object of this Paper is to lay before the Society the general facts 
of the case. 

From the explorations in different portions of the world, it 
has been learned that in connexion with a Placer mine, gold may 
be found—first, in the mother-rock (reefs or veins) ; second, in the 
higher shallow alluvium of the valley (shallow placers) ; third, in 
the lower deep alluvium of the valley (deep placers); fourth, in the 
alluvium of the beds of the high, now dry, supplementary streams 
of the ancient or primary valley (dry gulch placers) ; and fifth, in 
the shelves,. or high level flats, on the sides of valleys (shelf, reef 
or bar placers),* the latter being the relics or records left of the floor 
of the ancient primary valley—they proving that prior to the pre- 
sent time the gold was in the first instance deposited in. a compa- 
ratively wide shallow valley; while the alluvium of the present 
stream is the rewashed drift of the ancient valley mixed with newer 
detritus. Now in modern times, in none of the valleys of the Co. 
Wicklow has gold been found, or even looked for, except in the 
first, second, and fourth cases. 


1 Gerrard A. Kinahan, Scientific Proceedings, Royal Dublin Society, vol. ili. 

2 Geology of India, Part iii., ‘‘ Hconomic Geology,’’ by V. Ball, m.a., F.G.8. 
_ 3% The term reef is, in part, confusing, as ‘‘reef mining,’’ as used in some countries, 
refers to the crushing up of the quartz veins or reefs—while in other places the same 
term ‘‘reef’’ is applied to the high level flats. 


40 Scientific Proceedings, Royal Dublin Society. 


The gold of this portion of Wicklow has been found sparingly, 
without tin ore, in “ black sand,’ and more abundantly in con- 
nexion with tin ore and wolfram. On the accompanying map I 
have marked in red (they being copied from the maps of Gerrard 
A. Kinahan) the places in the immediate vicinity of the Gold-mine 
Valley where gold has been found, and with blue lines most of the 
principal open casts made in search of the “quartz-reef” or “mother- 
rock” of the gold. To the westward, in the Coolbawn valley, 
gold and tin were found in quantity north of where the letter A 
is marked on the map; in the S.W. branch of the Gold-mine river 
gold and a quantity of tin were found north-east of the place where 
B is marked; while in the 8. branch they were found north and 
north-east of the letter C; it may, therefore, be naturally suggested 
that if a “mother-rock” exists, it ought to be found somewhere 
near one of these points; while, as far as can be learned from the 
records, no researches have been made in connexion with such an 
idea. Mills indeed suggested that the high ground of Ballinasil- 
loge, to the north of B, should be tried, but his suggestion was 
overruled by Weaver and Kirwan: there is also the high land of 
Knockmiller, between B and C, that has not been tried; while 
immediately eastward there is more untried high land, although 
in the valley of the townland of Mongan there are indications that 
strongly suggest the presence somewhere thereabouts of a mineral 
vein. It therefore appears to.me that until after the high land 
in these localities has been investigated it would be rash to assert 
no gold reef exists. | : 

To the westward, in the upper portion of the. Tomaskela river 
valley, gold has been proved to exist, but never worked for. In the 
Coolbawn stream and its eastern tributaries all the diggings were 
shallow, the search being abandoned when the head of drift be- 
came twelve or fifteen feet deep. However, three miles to the 
N.W., near the Darragh water, where the alluvium was again 
shallow, the gold was worked. There is, therefore, in the Cool- 
bawn valley three miles in length of untried deep alluvium.’ 

In the valleys of the S. W. and S. branches of the Gold-mine 


* Weaver began trials in this deep ground; but when he found the drift was deep 
enough to prevent the country people from working there, he abandoned them, deep 
works being contrary to his instruction, 


Kinanan—On the Possibility of Goold in Co. Wicklow. 41 


river there are no workings more than thirty feet deep, while 
nearly all of them are less than twelve or fifteen feet; there is 
therefore, in this valley at the least, over a mile of untried deep 
ground. 

In connexion with the Darragh water or Aughrim river, the 
gold-bearing tributaries are:—-the Tomnaskela river, the Cool- 
bawn stream, the Ow river, the Kilmacreddin stream, the Clone 
stream, the Ballintemple stream, and the Gold-mine river ; yet the 
alluvium of the valley has not yet been tried, except at Ballycoog 
steps, where gold was proved. The distance from the inver or 
mouth of the Tomnaskela river to the Lower Meeting at Wood 
bridge is over eight miles. 

Gold has eon found in the sand of the Ow and in the alluvium 
of its tributary, the Mucklagh brook ; the untried valley from the 
Mucklagh brook to the Dee water valley being over six miles 
in length. 

Only the shallow alluvium of the upper tributaries of the Mac- 
reddin stream have been worked, there being a length of over three 
miles of deep alluvium between them and the Darragh water. 

In connexion with the Ovoca, there is gold in the gossan of the 
Ballymurtagh, Upper Cronebane, and Connary mines, in the river 
gravel at Castle Macadam, and in the alluvium of the Darragh 
water and its tributaries. ‘There is, therefore, from the Ovoca 
mines to the sea at Arklow a length of over six miles of untried 
deep alluvium. So much for the untried deep and shallow placers 
in the neighbourhood of the Gold-mine Valley. 

In connexion with the S. branch of the Gold-mine Valley, one or 
two “dry gulches” were worked by Weaver, who got in them “large 
gold.” Nowhere else does there appear to have been exploration 
made in search for “ dry gulches.” 

The relics of the more’ ancient valleys, that is, “shelf,” or “bar 
placers,” have never been looked after; yet in many places there 
is a possibility, if not a probability, that such golden relics might 
be found. Experience in America and Australia has proved that 
such deposits usually, although not always, occur in the shelves at 
the convex side of valleys, below the level of the source of the 
gold; and such shelves, possibly gold-producing, are very conspi- 
cuous in places along the valleys of the Ovoca, the Darragh water, 
and the Gold-mine river, at heights below the known points at which 


42 Scientific Proceedings, Royal Dublin Society. 


the gold was found in quantity associated with tin ore and wol- 
fram. None of them have ever as yet been explored. 

There are other places in this neighbourhood, such as Ballin- 
glen and the Tinnahela streams, in which gold has not yet been 
recorded or tried for, although the indications would suggest its 
existence ; but these it is unnecessary further to refer to. 

In conclusion, however, I would submit to the Society, that 
to me it appears rash to give an opinion on the non-existence 
of gold, while the miles of alluvial ground now enumerated still — 
remain unexplored, or while no attempt has been made to explore 
the shelves of the valleys. 


[ 8 J 


VII.—ON THE CALCITE CRYSTALS FROM THE IRON MEA- 
SURES OF THE COUNTY ANTRIM. By PROFESSOR 
J. P. O'REILLY, C.K. (Prare II.) 


[Read, February 19, 1883.] 


In the very interesting Paper read before the Natural Science sec- 
tion of the Royal Dublin Society, April 11th, 1881, by Mr. Philip 
Argall, on the “Tertiary Iron Ore Measures of Glenariff Valley, 
Co. Antrim,’’! he makes frequent mention of the “ aragonite crys- 
tals” which accompany the ores and are found in geodes or vugs 
. of the roof of the ore bed, or in cells of the amygdaloidal dolerite 
along with zeolites, as also at other points of the deposit in fine 
acicular crystals. He remarks, p. 158: “‘ Hence a display of crys- 
tals (aragonite) on the roof is regarded by some as a sign of poverty; 
similarly as a display of spar crystals in a standing vein indicates 
poverty of mineral matter in the percolating fluids when the run 
was being filled.” At page 161 he says, ““when approaching a 
dyke, cracks in the Rawement are frequently filled with acicular 
crystals of aragonite.” 

Mr. Argall very kindly eee for me the linings of a couple 
of fine geodes, and in the accompaning letter explained by a sketch 
the position of the vugs or cavities relative to the ore bed in which 
. the crystals are found. Subsequently, in October last, Professor _ 
Hull handed me for the Museum collection of the Royal College 
of Science some specimens of acicular crystals from the same 
contact found at Cushendal, Co. Antrim. I had previously been 
engaged in examining the crystals of the vugs forwarded me by 
Mr. Argall, and from the densities obtained had reason to consider 
these crystals as being really calespars. A. further examination of 
the acicular crystals presented by Professor Hull lead me to the 
same conclusion in their regard, and I now beg leave to submit the 
results of this examination from the points of view of density, 
crystalline forms, cleavage, and hardness. . 


' Proceedings, vol. iii. (new series) part iv., p. 151, 


44 Scientific Proceedings, Royal Dublin Society. 


The density of the acicular crystals presented by Professor Hull 
was found 2°71. 


_ That of part of a honey-coloured crystal nese by the same 
271. 

The density of calespar crystals is given at 2°6 to 2°8. 

And for the purest crystals 2°72. 

Whereas that of similarly pure aragonite crystals varies from 
2°9 to 3:00. 

It may, therefore, be concluded that from this character alone 
the crystals in question are calcspars. The further examination of 
the crystalline forms, cleavage, and hardness, still further confirms 
this conclusion. The crystals are scratched by aragonite, and the 
cleavage is very distinctly rhombohedral, and in no way that of 
aragonite. The crystalline forms are sufficiently distinct in the 
small acicular crystals to allow of measurement, and are clearly 
referable to the rhombohedral forms of calespar. Thus the acicu- 

-lar-crystals show on the sides the zigzag striations characteristic of 
certain scalenohedral forms and the angles measured on the long, 
short, and middle edges, give sufficiently approximatively the values 
corresponding to the scalenohedral form. R12. 


Long edge, calculated angle, 125° 47’, found 125° 30’. 


Short edge, 8 5 L408. Ae oul 

Middilexed ser sium Sa llO7 scone. — 
These crystals are terminated by the forms 

4k, terminal edge, — : 5 : : 65° 50’, 


Slush, calculated angle, 78° 51’, found 78° 00’, 


and R. 
The honey-coloured partial crystal. from Cushendall presented 
by Professor Hull shows the forms 


R12 - 2K, and cleavage terminal forces of R. 


_ The crystals occurring in the geodes of the iron ore bed present 
scalenohedral forms oscillating in a remarkable manner, and in the ~ 
central zone of each face a band, or red stripe strongly marked, 
and representing the rhombohedral form — 2R. The examination 
of several of the crystals shows that on either side of this band, 
itself somewhat rough, there is an oscillation of scalenohedral 


O’ Reitty—On the Calcite Crystals of County Antrim. — 45 


forms, marked by ridges and furrows running nearly parallel to 
the basal section, and giving rise to a rounded face. These oscil- 
lating forms represent the scalenohedrons - 2R? and — 5.RZ. 


Long edge, calculated, 158° 16’, found, 158° 57’ 
— 2k? § Short edge, Bs Go Oars. 93° 10’ 
Middle edge, an, ey Loom ene elo ay 
Long edge, BY - 164° 59’, found, 165° 24’ 
=5/R2 | Short edge, i TO DAA oy} Oe D8. 
Middle edge, a Iss OW gee BO 


The roughness of the faces, and the rounded faces of the middle 
edges rendered closer approximation difficult. The oscillation of 
these forms gives to the surface of the crystal a feathered appear- 
- ance, the feathering proceeding out symmetrically on either side 
from the red stripe representing the face — 2R. 

In other vugs occurs a combination of forms somewhat different. 
Thus, there is found a central pyramid of which the faces pre- 
sent the roughness of a ground glass plate with cleavage planes 
traversing them at regular intervals. This form represents the 
pyramid $fh2: 


Calculated polar edge, 135° 511’, found, 185° 57’. 


On the alternate polar edges appear in process of formation, and 
in different stages of that process, the faces of the scalenohedron 
= REE | 

Long edge, calculated, 161° 53’, found, 161°. 

Short edge, | s ION Dy sign LOI 


This last form is rarely complete, and its faces rarely cover the 
whole of the underlying pyramid, and in the same manner as in 
the case of the previously described crystals, leave a space or band 
along the middles of the alternate pyramidical faces, but without 
any red stripe. | 

The conditions having led to the deposition of the red mineral 
matter (peroxyde of iron apparently), present interest in so far as 
they might lead to an estimate of the temperature of the solution 
from which the erystals were formed. ‘The only record existing as 
to actual experiment in this respect is that of Sénarmont (An. de 
Ph. and Ch., t. xxx. p. 129), who transformed the hydrated 
peroxyde of iron into anhydrous peroxyde by heating it in a 


46 Scientific Proceedings, Royal Dublin Society. 


closed vessel at 180° C. in presence of water, or in a saturated 
solution of chloride of magnesium or chloride of calcium. The- 
product obtained was red, amorphous, and resembling the common 
variety of natural sesquioxyde of iron. Why the central band of 
the crystal should alone present this oxyde is not so easily ex- 
plained, unless by the hypothesis that crystals of either carbonate 
of iron or iron pyrites were deposited on this surface, and then 
subsequently transformed into peroxyde. That certain faces of 
crystals induce, or facilitate such deposits is well known ; and that 
the state of the surface of the face is an essential factor in the 
phenomenon is also well known: the primary cause is, however, 
less clearly explainable. 

That no precise conclusions could be drawn from the presence 
either of aragonite or calespar as regards the temperature of the 
solution from which the erystals were deposited would appear 
from the synthetical experiments of G. Rose, which tend to prove 
that both calcite and aragonite may be formed in warm solutions. 
The conclusions of a review of all the synthetical experiments 
made up to the present relative to these two minerals are thus stated 
by Messieurs Fouqué and Levy in their remarkable work, “ Syn- 
thése des mineraux et des roches”’ (1882), p. 203 :—“ In the 
ereater number of cases, natural calcite and aragonite appear to 
result from the decomposition of solutions of bicarbonate of lime 
more or less concentrated, and more or less warm. The crystals 
formed affect the rhombohedral, or rhombic forms cresonn to the 
temperature at which the crystallization takes place.” ; 

In this case the presence of the red band of sesquioxyde of iron 
would tend to prove that the solution, at one particular stage, was 
warm, and as this was a final stage, the probability is that the 
calcite crystals were formed from warm solutions of bicarbonate of 
lime. 


etal 


VIIIL—NOTES OF TRANSIT OF VENUS, AS SEEN AT THE 
CRAWFORD OBSERVATORY, QUEEN’S COLLEGE, 
CORK, 6rm DEC., 1882. By ;PROFESSOR ENGLAND. 
Communicated by Howard Grubb, F.r.s.a. 


[Read, December 18, 1882.] 


Tu time was taken by chronometer set to Greenwich time, and 
checked by the signal gun at 1 o’clock of the day of the transit, the 
proper allowance being made for the time occupied in the trans- 
mission of the report. The observations were made with the 
8-inch refractor, furnished with polarizing eye-piece. The field 
of view was by this contracted to about 5’ diameter. 

The telescope was directed to the sun at about 1* 30™, and 
adjusted so that the E. limb of the sun bisected the field of view, 
and the planet should appear near the middle. ‘A few minutes 
before the calculated time of contact my attention was altogether 
directed to the dark part of the field, hoping to see Venus before 
contact. In this respect I think the limited field was an advantage; 

-but no appearance whatever was observed until after 25 2™, when 
a slight notch was observed on the sun’s limb very near the centre 
of the field. It took a few seconds before I could be absolutely 
certain of this, on account of the apparent undulatory motion on 
. the sun’s edge. ‘The observation may therefore be considered of 
no value as regards time of contact. The planet gradually ad- 
vanced on the sun—the disc beautifully defined—until it had 
somewhat more than half entered on the sun’s disc, when the part 
without the sun became visible, the eastern edge being distinctly 
luminous, very similar to what is seen in the moon a few days after 
new moon, except, of course, the planet was much darker than the 
moon, no difference being apparent between the part on the sun’s 
disc and that without it, except near the eastern edge. The cusps 
now gradually approached, and at 2" 21™ 51° I signalled to my 
assistant to register the time. It was not, however, until twenty 
seconds after, viz. 2" 22™ 118, that I felt satisfied of contact, and 
the limb of the sun was only clearly visible outside the planet at 


48 Scientific Proceedings, Royal Dublin Society. 


2h 22m 165. AsT have stated, much uncertainty necessarily results 
from the flickering motion of the cusps. 

During the whole time the planet was visible it appeared per- 
fectly circular; no deformity whatever, as ‘black drop,’ ‘pear 
shape, &c. When once fairly on the disc of the sun I did not pay 
much attention to any subsequent phenomena. Our Observatory 
being situated within the College grounds, and being chiefly in- 
tended for educational purposes, I was anxious to have our stu- 
dents, as far as possible, see the transit. For this purpose the 
image of the sun was thrown on a sheet of white paper by the 
siderostatic telescope, the image being about 6 inches in diameter : 
the image of the planet was very distinct, and over one hundred 
individuals were thus enabled satisfactorily to see the transit. 

I should have stated that observations here made by the 
siderostatic telescope, one before the junction of the cusps at 
2h 21™ 275, the other after the light of the sun was well seen 
at. the eastern side, 24 22" 205, 


29 


IX.—OBSERVATION OF THE TRANSIT OF VENUS, 1882, DE- 
CEMBER 6, MADE AT THE ARMAGH OBSERVATORY. 
By J. L. HE. DREYER, Pu. D. 


[Read, December 18, 1882. ] 


_ Ow the morning of the 6th of December the sky was quite over- 
cast, and snow fell for about an hour between nine and ten o’clock. 
About noon it began to clear, and with the exception of a few light 
clouds passing now and then, the sky continued perfectly clear 
until about three o’clock, when the sun was again hidden by 
clouds. 008 

For observing the transit I employed the 15-inch reflector, 
which is equatoreally mounted in the east tower of the Armagh 
Observatory. The instrument can be used either in the Casse- 
grain or in the Newtonian form: I preferred the latter, and had 
a plane unsilvered mirror substituted for the usual metallic flat 
mirror. ‘The negative eye-piece (power 140) was furnished by 
Mr. Grubb, with a wedge of neutral-tinted glass, which permitted 
_ the observer to diminish the intensity of the solar heat so as to 
make it pleasant to the eye without rendering the mottled appear- 
ance of the.photosphere indistinct. The eye-piece was carefully 
~ focussed on the solar limb, and on several facule, and with the ~ 
diminished aperture of seven inches both the limb and the mottled 
surface of the sun were extremely well seen. : | 

I tried to observe the external contact of Venus with an aper- 
ture of eleven inches, but the definition was far from good, the 
limb ‘boiling’ violently. At 1" 36" 14*, local mean time, I was 
certain that the outer contact had taken place. Having exchanged 
the diaphragm used with one of seven inches aperture, the defini- 
_ tion was much improved, and before the second, or internal contact 
occurred, it became almost all that could be desired. At 15 49™ 31s 
the whole circumference of Venus was visible, that part of the 
* planet which had not yet entered on the sun being projected on 
the bright sky adjoining the solar limb. At 1° 54™ 49°6 Venus 
was completely on the sun; but a faint, narrow shade-like band ° 


SCIEN. PROG., R.D.S.—VOL. IV. PL. I. ' E 


50 | Scientific Proceedings, Royal Dublin Society. 


appeared at this moment, filling the interval between the cusps. — 
This shade was steadily visible until 12 55™ 24*-5, when it broke, 
and gave place to a very thin bright line which separated the two 
limbs. Be 12 55™ 51 I noted “interval between limbs very con- 
spicuous.”’ 

On referring the same evening to the volume of British Obser- 
* vations of the Transit of 1874, the observation of ingress by 
Commander Wharton, at Rodriguez, was found to correspond in 
most particulars with mine, and his Fig. 3, on Plate x1v., repre- 
sents the “shade,” as seen by me just hoe breaking. 

The transit was also observed by the Rev. Charles Faris, Assist- 
ant Astronomer, with the 71-feet achromatic finder (object-glass 
3°8 inches) attached to the roleeioe As the pier hid us from one. 
another, and we took care to record what we saw without speak- 
ing, our observations may be regarded as perfectly independent. 
Mr. Faris did not’ see any disturbance of the limb at internal con- — 
tact, but saw the cusps meeting at 1> 55™ 10" 6. He had observed 
anrenuel contact at Lb 35™ 35°, — 


ear | 


X.—NOTES ON THE TRANSIT OF VENUS, AS OBSERVED AT 
STREETE, CO. WESTMEATH. By W. E. WILSON, F.R.S.A. 


[Read, December 18, 1882. ] 


Tue 6th was cloudless throughout. The error of the Observatory 
mean time clock was got by a transit of the sun at noon. The ~ 
24-inch reflector was stopped down to 12 inches, and a polarizing 
_eye-piece used: The 4-inch finder was also used with a power of 75. 
The first contact was observed at 1" 31™ 54° Streete mean time. 
I was not quite sure of the exact position-angle that contact would 
take place at, so that I am sure the above time is a few seconds late. . 
The time I calculated for first contact was 12 317 14°S.M.T. At 
1» 38™ the entire dise of Venus could be seen against the corona. 
The planet seemed much darker than the corona, and was sur- 
rounded by a thin ring of silvery light. This ring was much 
brighter at the place marked in the following diagram by $. I 
suppose it was caused by a bank of clouds in the planet’s atmos- 
phere. 


Parte 


Internal contact occurred at 1° 52" 14° 8. M. T., and is, I be- 
lieve, very close to the calculated time. . There was no appearance . 
of “black drop.” The two cusps of light were almost quite sharp, 
and gradually closed up until they touched. As soon as Venus 
was well on the disc I mounted the spectroscope, and made a care- 
ful search for any absorption lines in the planet’s atmosphere. | 


02 * Screntific Proceedings, Royal Dublin Society. 


Nothing of any certainty was observed. I thought some of the 
lines near D were thickened a little at their base, but I would not 
place much reliance on the observation. The sun by this time.was | 
getting very low, and the image of the planet was unsteady. If the . 
atmosphere of Venus is about the same depth as the earth, it will’ 
easily be seen that it would be an exceedingly thin ring round the 
planet, and by placing the planet over half the slit it would be 
most difficult to see the short absorption lines. My telescope being 
a Cassagranian, and giving a large image of the planet, would 
have a better chance than the Newtonian or Refractor. During 
the forenoon the sun was observed on the chance of seeing a transit 
. of a satellite of Venus with a negative result. 


Bl 


XI—ON MODES OF DEALING WITH ECHOES IN ROOMS. By 
GEORGE JOHNSTONE STONEY, D. Sc., F.R.S., a Vice- 
President of the Society. 


[Read, December 18, 1882.] 


In almost all large apartments echoes are troublesome. If the 
room is used for music, echoes destroy the purity of the sound ; if 
for oratory, they render the utterance of the speaker indistinct. 
Any mode of mitigating these bad effects is useful, and if it goes 
the length of practically annulling them, it will be of signal ser- 
vice. This induces me to lay before this section of the Society the 
result of some experiments on the subject which I fe occasion to 
make several months ago. 

Echoes in rooms arise from sound ae the ear, not only 
directly but also after reflection, and sometimes after more than 
one reflection, from the ceiling, the four walls, and the floor. Ifa 
large audience be present, the floor ceases to act as a reflecting sur- 
face, and there will remain the walls and ceiling. In all cases, the 
effect which results largely depends on the circumstance that the 
sound-waves, especially those of low pitch, aré of considerable size 
compared with the extent of the wall, so that reflection is not of 
that simple and definite kind which occurs when light is reflected 
from a mirror, but, partakes largely of the diffuse character which 
we see when light falls on surfaces which are not polished. The 
reflection of sound-waves is intermediate between the two ways in» 
which light is reflected, and tends more towards true reflection in 
the case of the short waves which belong to sounds of high pitch, 
_while the reflection becomes more and more an irregular scattering _ 
of sound from the reflecting surface, in the case of long waves of 
low pitch. This difference of effect in the cases of long and short — 
waves is well known to the mathematicians who have studied the 
interference of waves, and it is unnecessary to give the proof here 
as it may be found in all text-books on-the subject. But it is well 
. to point out that it contributes largely to that marked indistinct- 
-ness which echo in a room gives to the utterance of an orator. The 


54 _ Scientific Proceedings, Royal Dublin Society. 


fundamental sounds of a man’s voice which constitute the chief body 
of the sound consist of long waves, eight or twelve feet in length, 
and are returned to us in varying directions from almost all the 
reflecting surfaces from which the sound can be scattered back. 
They thus constitute a loud echo of these low tones of the voice. 
On the other hand, the much more acute sounds upon which 
articulation depends, which make the difference between one 
vowel-sound and another, or between one consonant and another, 
consist of waves so short that they are reflected from a wall almost 
quite in accordance with the law of reflection, and only reach such 
ears as are in the definite line in which they are reflected. But few 
of the audience can be so placed; these hear, indeed, the proper 
sounds, but disordered as regards time, so that it is often diffi- 
cult for them to follow the speaker: and the rest of the audience 
are worse off; they hear an abundant sound, but cannot easily 
catch any ones This latter effect is apt to be felt in a large room 
with bad echoes, even where the orator speaks so slowly that his 
syllables reach his audience almost separately. In such cases, the 
lighter and shriller elements of drticulation are drowned in the 
fundamental tone of the speaker, reinforced by reverberation from 
the ceiling and walls; and the mischief only increases if the speaker 
endeavours to meet it by speaking very loud. All that he can 
successfully do is to hiss out his consonant sounds with unnatural 
‘strength, while taking care not to allow the fundamental sound of 
his voice to pass beyond a moderate strength. 

In contrast to the case of an audience occupying the whole 
floor stands that of a single listener placed in a position selected 
because it is the focus of reflections from suitably curved surfaces. 
In this case the higher tones are reflected with such precision to the 
focus in which the listener stands that they reach him with almost | 
no abatement, while the bulk of the sound, the fundamental tone ~ 
of the voice, is enfeebled because much of it has been scattered by 
the reflecting surfaces in other directions than towards the focus. 
Hence, in such situations, the articulation of the speaker seems . 
- preternaturally distinct, as all persons who have visited such a 
whispering gallery as that in St. Paul’s must have observed. - 

These remarks will serve to direct attention to the conditions of 
the problem. The way to deal with it falls naturally under two . 
heads, according as we have to make the best we can of an existing 


SORE Modes of Dealing with Echoes in Rooms. 55 


room without altering it, or are at liberty to prepare the room 
specially. 

In the first case, it is obvious that by eee the speaker in one» 
corner of the room, we eliminate the direct echo of the two walls 
which meet at that corner. This is already a great gain, especially 
if one of the other walls of the room is broken into |spaces by win- 
dows. In that event there will remain little direct echo except 
from the ceiling, and the farther end wall: meaning by direct echo 
the sound which has only once been reflected. By this simple 
contrivance it has been found that if the speaker takes proper care 
with his enunciation, all the audience can be made to hear suffi- 
ciently distinctly, except those occupying a few definite situations, 
which can be easily ascertained by experiment, ein, might with 
advantage be left without seats. 

Still further mitigation may be effected by placing the speaker 
in that corner of the room where the two worst, that is, the most 
uninterrupted, walls meet, and by bringing a canopy of sufficient. 
size as close.over his head as convenient. In the experiments which 
have been made this canopy was made of cotton cloth stretched on 
a horizontal. frame six feet square, and was brought within a few 
inches of the head of the speaker. It should be oh larger size if 
placed farther from him, and will be sufficient for’ our purpose if « 
it prevents his seeing either the ceiling or the upper parts of the 
walls opposite to him. The anticipated effect is as follows :—Distin- 
~ guishing the sound of the speaker’s voice into the fundamental 
note on which he speaks and the overtones which give articulate- 
ness to the sound, it. was expected that the overtones, consisting of 
waves so short that they cannot readily bend round obstacles, would 
reach the audience with nearly the’ full force given to them by the 
speaker, and that but little of this constituent of the sound would 
bend enough to reach the ceiling and the walls. On the other 
hand,. the fundamental note would more readily spread upwards, 
and would, therefore, produce some, although a reduced, echo. ‘This 
slight echo along with the part of the fundamental note received 
“ directly from the speaker’s mouth, ought apparently to be heard 
as a fundamental note of the proper strength to be rendered arti- 
culate by the overtones received directly from the speaker, and 
therefore received by the ear at the proper times to make the 
utterance distinct. In the experiments which have been made it 


56 Scientific Proceedings, Royal Dublin Society. 


was not found practicable to distinguish all the elements which 
theory seems to indicate, but of the marked improvement effected 
by introducing the canopy there can be no doubt. 

This concluded the first part of the inquiry. The second was 
directed towards ascertaining whether it is possible to construct a 
room without echo, or to alter an existing room in such a way as 
will free it from echo. The experiment I proposed to make was to 
hang paper draperies on the walls and from the ceiling ; but before I 
incurred the considerable trouble and expense of doing this I acci- 
dentally found that one of the large apartments of the Exhibition 
Palace, in Harlsfort-terrace, had its walls papered over a lining of 
canvas, the canvas being a short distance (from one-eighth to a 
quarter of an inch) in front of the framework over which it was 
stretched. These are precisely the conditions that I had desired ; 
and, very fortunately, the ceiling of this room’is so nearly covered 
by skylights that there is but little echo from it. On trying the 
experiment in this room, with the floor occupied by an audience, 
I found no appreciable echo that could be referred to the walls. 
There was indeed a very short echo, very unlike the prolonged 
echo of an ordinary room of the same shape and size, sounding like 
the letter R very roughly pronounced, with a faint burst, which 
lasted not, I think, more than the eighth or tenth of a second. 
This I, believe to have been due fo the partitions which Sea 
the numerous skylights of which I have spoken. 

‘From this experiment I believe it may be safely inferred, that 
a concert hall or room for public oratory may be effectually freed 
from echo by the extremely simple expedient of lining its walls 
and ceiling with canvas, kept at a slight distance away from the 
walls. The ceiling must be included in this treatment, if it'is to 
be effectual, as a large part of the echo usually comes from it. The 
canvas may be papered, or distempered, or painted, so that there 
- need not even be any change in the room visible to the eye. 


Neo ccs 


XII.—ON DR. EDDY’S HYPOTHESIS THAT RADIANT HEAT 
IS AN EXCEPTION TO THE SECOND LAW OF THER- 
MODYNAMICS. ‘By GEORGE F. FITZGERALD, M.A., 
ee CDy 

“[Read, December 18, 1882.] 


In the Scientific Proceedings of the Ohio Mechanics’ Institute for 
July, 1882, and at the meeting of the American Association for 
the Advancement of Science in Montreal, Dr. Eddy proposed an 
exceedingly ingenious experiment, by which he expected that it 
would be possible to get radiant heat to pass from a cooler to a 
hotter body. I had the pleasure of hearizig his Paper at Montreal, 
and though I then ‘saw no flaw in his reasoning, I pointed out to 
_ him that he had only taken two of the bodies concerned into con- 
sideration, yet I dared not express a decided opinion on the matter 
without further consideration. The further consideration has re- 
sulted in my thinking that the cone is not valid, as I hope to 
be able to point out. 

‘I shall take what seems to me an experiment seus ek simpler 
in theor y, though one that would be harder to carry out in ae ha 
than Dr. Eddy’s. 

Suppose that two regions A and B, separated by three parallel 
screens /, m, and n, having apertures in them 2, y, z, capable of 


being opened and closed from the centre, so as to make everything 
perfectly symmetrical ‘round the line AB perpendicular to the 
screens. - Now, if v be opened for a very short time, a certain quan- 


tity of radiant energy will escape out of A into the region between 


Zand m; and if y be opened when this heat reaches m it can cer- 
tainly be let on into the region mn; and if z be similarly opened 
SCIEN. PROC., R.D.S.—VOL. Vien Dep lee 


58 Scientific Proceedings, Royal Dublin Society. 


when it reaches it, this radiant heat will get into B. While s was 
open, however, some heat left B; but as Dr. Eddy observes, y may 
be closed so as not to let this even get through the screen m, and it 
can be all returned into B by reflection through s or some other 
aperture. So far I entirely agree with Dr. Hddy, and so far it 
seems as if the result had been to transfer heat from A to B with- 
out B’s losing any heat by having it transferred to A. As I 
warned Dr. Eddy when I heard his Paper, there are, however, 
other bodies and regions to be considered besides A and B. ‘There 
are more than two bodies considered: there is the region of the 
screens. Consider what happens when the heat that escaped out of 
B into the mn region tries to get back into B. Some door must be 
opened to let it pass, and, while it is passing in, an, at least, equal 
amount.of heat will be passing out of B into the mn region, so that 
you can never really get the heat that has once left B back into B 
again. This is true whether you adopt doors over fixed apertures | 
such as I have supposed, or moving apertures such as Dr. Hddy 
proposed. What really takes place is this: a certain quantity of 
heat escapes out of A and reaches B, and a not less quantity of heat 
leaves B and is kept entangled in the region of the screens, and it 
is only possible to let the heat pass from A to B by means of this 
third region. Hence this only really comes to the same thing as 
letting A radiate some of its heat into the screen region while B is 
kept closely shut up. Now be it observed that Dr. Hddy practi- 
cally postulates that this screen region is at least colder than A—in 
fact he assumes’it to be perfectly cold, 7. e. to contain no radiant 
heat excépt what is admitted from A and B, so that it is by no 
. means contrary to the theory of exchanges that A might cool by 
radiating into this region. 

This seems to me to be a perfectly satisfactory explanation of 
what would take place, though it, for the present, dispels the 
vision of an immortal universe. This experiment of Dr. Eddy’s, 
however, seems to call attention to the fact that a region of motion- 
less ether must be considered as practically a cold body capable of 
absorbing radiations. 


[ 59 ] 


XIIT.—ON EQUAL TEMPERAMENT, AND ON THE CAUSE OF 

THE EFFECT UPON PIANO MUSIC PRODUCED BY 

. THE KEY IN WHICH IT IS SET. By G. JOHNSTONE 
STONEY, D.Sc., F.R.S., a Vice-President of the Society. 


[ Read, March 19, 1883. ] 


PERHAPS of all the canons of Art, that one is the most important 
which declares that correctness in Art is not identical with accuracy 
in Mathematics. It would be no just criticism of the outline of a 
drawing to say that inaccuracies could be detected with a micro- 
scope. Correctness in a work of Art has been fully attained when 
the deviations have been kept below what can be noticed by 
the human beings who are to be impressed by that work of Art. ” 
Hence in Art a latitude within certain narrow bounds is not only 
allowable, but commendable. Hven when no other advantage is 
gained by it, the tolerance of it, at all ous preserves the artist 
from misapplying his powers. 

But there are cases where new artistic fete of importance can 
be obtained by deviations, and then they deserve to be commended 
on other ground, and in a higher degree. Thus, in the pictorial 
Art, that part of the appearance of standing out in relief which 
is given to natural objects by what astronomers call parallax is 
absent. All the objects in the painting are necessarily in one 
plane, and we cannot judge of their distances by our binocular 
vision, or by slightly moving our heads, as we habitually do judge 
of the distances of natural objects. Hence the artist is only able 
to suggest these distances by the sizes of the objects in his picture, 
and by the colours, lights, and shades he throws over them—the 
parallactic element is necessarily absent. 

If the artist augments the effect produced by colours, lights, 
and. shades beyond what exists in natural objects, he can in part 
‘supply the place of the absent element; and, if he avails himself 
of this resource with skill and moderation, the augmentation falls 
within such narrow limits, that it is not felt by the beholder as a 


SCIEN. PROC., R.D.S: VOL. IV. PT. II. G 


60 _  BScientifie Proceedings, Royal Dublin Society. 


deviation from nature, and is to be appreciated as artistic excel- 
lence: if it transcend those limits it is perceived to be exaggeration, 
and offends. 

The principles which underlie these remarks apply with singular. 
force to music. Judging from the literature on the subject, it may 
be said that people of an arithmetical turn of mind are sometimes 
apt to forget that artistic correctness has been fully attained when 
the outstanding errors have been reduced below what the cultivated 
ear can perceive, and both the arithmeticians and those who are 
devoted to the simpler forms of melody and harmony are apt to 
overlook what one would think is very obvious—that some sacrifice 
of one artistic effect may be welcomed when it procures for us new 
artistic effects of sufficient value, and especially where the new field 
of effects is of such vast range as it is in instrumental music, and 
the effects themselves of a kind to be keenly relished by those who 
have the good fortune to be gifted with a comprehensive apprecia- 
tion of harmony. 

Of this kind are the advantages acquired by tuning pianos on 
the system of equal temperament. In this method of tuning, each 
octave is divided into twelve equal semitones. This method of 
tempering plainly puts it within the power of the composer to in- 
dulge in absolutely unlimited transition from key to key, for. it 
provides the same intervals in all the keys. 

It was for a piano tuned in this way that Sebastian Bach com- 
posed the unrivalled preludes and fugues of his “‘ Wohltemperirte 
Clavier,’ and many of these, as well as a great deal of the best 
modern music, would be impossible without the unrestricted power 
of modulation which is thus provided. This immense advantage 
ought to be candidly admitted by those who recommend other 
methods of tempering. 

On the other hand, there are effects and exquisite effects, which 
cannot be attained with instruments tuned in this way, which will 
only come forth when suitable music is executed in the natural 
scale, 7.e. the scale indicated by the mathematical theory, or in a 
scale very closely approximating to it. This natural scale does not 
in its fifths differ sensibly from the scale of equal temperament, , 
but its thirds and sixths are perceptibly smoother; and it has two 
supertonics to be used respectively according as this note is asso- 
ciated with dominant or subdominant harmony. I would wish 


Stron—EyY—On Equal Temperament upon Piano Music. 61 


. to urge that it is a great pity that, when glees are sung without 
accompaniment, more care is not taken to bring out the exquisite 
effects which enchant the hearer when the music which is adapted 
to it is rendered in this scale. . 

One obstacle to this is, that people become partisans. The 
Tonic-solfaists, who have widely advocated the natural scale, are 
sometimes not content without also disparaging tempered instru- 
- ments, forgetting that many of the. best instrumental effects have - 
no existence with the natural scale. And on the other hand, some 
lovers of the richest harmonised effects speak very unappreciatively 
of the praiseworthy efforts of the Tonic-solfaists to extend vlae use 
of the natural scale. 

_ The truth is, that each in its own place is the best, and we 
deprive ourselves of much of the legitimate delight of the most 
delightful of all arts by limiting our choice to one only—to either 
the natural scale, or the scale of equal temperament. 

I need not pursue these general considerations farther, for my 
immediate object is of limited scope. What I desire particularly 
to invite attention to is to one collateral advantage among those 
which render the system of equal tempering of importance to us, 
viz., that it provides us on the piano with twelve keys which differ 
essentially in the artistic effects which they can produce. 

Nothing about Art is more astonishing than the extreme sub- 
tilty and delicacy of the causes which weave webs of the strongest 
influence about our minds. They are very difficult to make out, 
and in many instances have defied every effort that has been made 
to bring them to light. It is my aim on the present occasion to 
endeavour to obtain some insight into one of these—to try to trace 
out what minute shades of difference produce that remarkable 
difference of artistic effect which we perceive in the various keys 
on the piano—to endeavour to find out why the key of A is so 
well adapted to joyous, bright, and sparkling effects, while its close 
neighbour, the key of Ab, is gentle, soft, and liquid—why D and E 

are brighter than Hip, and so on. 

This great difference does not depend in any considerable de- 
_gree on pitch nor on the tempering. In fact, as Helmholtz points 
out, if two pianos are tuned one a semitone lower than the other, 
these keys will preserve their distinctive characteristics on both. 
Even though the key of A on the one piano is made to consist of 
G 2 


: O25 | Scientific Proceedings, Royal Dublin Society. 


identically the same tones as the key of Ab on the other, their 
artistic effects will be wholly different. Nor does this variety of 
effect depend on tempering, for it is present on pianos carefully 
tuned on: the system of equal temperament, where all the semi- 
tones are alike, and it continues to be equally perceived by the ear 
on pianos tuned with all the little deviations from this system of 
temperament which are common in practice. We are thus driven 
to attribute it to some inherent difference of effect of the black 
notes and the white notes on the piano. Helmholtz suggested this 
as the direction in which the explanation must be sought, and by 
making that suggestion he furnished the key to the solution, which, 
however, he does not himself pursue farther. - 

Each note of the piano is a complex tone. In addition to the 
fundamental tone, it contains its octave, its twelith, and its double 
octave, but these harmonics are present in proportions which differ 
somewhat according to the strength with which the note is struck. 
Hence the quality of the note is subject to a slight variation ac- 
cording as it is struck firmly or gently. In the first case the tone 
is of a richer quality ; in the second case it is softer, ¢.¢. it contains 
a less proportion of the higher harmonics. Now upon the pianos 
upon which I have experimented there was a very slight, but still 
perceptible, difference in intensity with its accompanying difference 
in quality, when the regulated impact of a mechanical apparatus 
was alternately delivered upon a white and on an adjoming black | 
note. ‘This difference appears to me to be somewhat greater when 
the two notes are struck successively by the same finger with what 
is judged to be the same force, and as nearly as possible in the 
same way. And the difference becomes conspicuous when the 
black note is struck from the more horizontal and extended posi- 
tion which the fingers that reach the black notes necessarily assume 
in the ordinary course of playing. The black notes will then give 
out a tone which is sensibly gentler, less rich, and softer, when the 
performer seems to himself to be exerting the same force on them and 
on the white notes. So far the effect is to be attributed chiefly to 
the positions of the fingers, and in small degree to the different 
sizes and proportions of the levers in the piano which terminate in 
the black and white notes respectively. Helmholtz suggests that 
the narrowness of the black notes may have some influence, but I 
have not been able to refer any part of the observed effect to this 


Stoney—On Equal Temperament upon Piano Music. - 68 


source. Their being separate from one another, with open spaces 
between, does however facilitate that horizontal position of the 
fingers which seems to produce a softening effect, unconsciously to 
the performer. 

On pianos which have been some time in use, the difference in 
quality between the black and white notes is very much augmented 
by the white notes having been more used than the black, and the 
hammers having, from this cause, become harder. On such pianos 
the greater part of the observed effect is probably due to this 
hardening of the hammers and consequent reinforcement of the 
upper harmonics; but it cannot be any part of the cause on new 
pianos; and, accordingly, on new pianos the variety of artistic 
effects in the different keys is less distinct. Assuming that the 
_ keys of A, Ab, Bb, C, D, E, Eb, F, and G, or their relative 

minors, are equally played upon a piano—and the great pre- 
-ponderance of music is in one of these keys—the white keys 
will, on the average, be used twice as much as the black; and 
when the softness of a new piano is beginning to be lost, the 
deterioration will affect the white keys more than.the black. It 
is easy to assure oneself that from this cause the black notes of 
pianos which have been much played on are, over a great part 
of the keyboard, sensibly softer than the white. | 

We have next to inquire how a softer quality of tone in the 
black notes, whether it arise from the fingering or from their 
having been less used, can produce the difference of artistic effect 
in the different keys which is observed. And here what occurs on 
the violin comes to our aid. The notes G, D, A will, whenever 
played, be reinforced by sympathetic vibrations in the open strings. 
And it,is found that on the violin the brightest keys are those 
in which the tonic, dominant or even subdominant, chance to 
fall on these notes. Hence the effect of joyous brightness is 
due to a slight difference of this kind between these notes of 
the scale and the rest. | 

_ Before proceeding farther, it is well to state the principal facts 
to be accounted for as they are presented to us in piano music. 
The bright effect of sharp keys appears to my ear to culminate in 
A major with three sharps, and to be present in a very: marked 
degree in D with two sharps, and in Ei with five. The soft effect 
of flat keys seems to me to be at its best in Ab major with four 


64. Scientific Proceedings, Royal Dublin Society. 


flats, and to be but little less distinct in Ep with three. Let us 
then compare the keys of A and Ab as the best representatives of 
the two classes in major keys. 

Now the first thing to observe is, that the tones of the scale 
which in the key of A are on the black notes are the tones 
which in the Eye of Ap are on the white notes, and vice versd. 
In fact— 


In A, fa, do, so, re (the fourth, first, fifth, and 
second of the scale), are 
on white notes ; 


and. (Gian tT aor ue dG) (the seventh, third, and 


sixth), are on black ; 
while 


In Ab, fa, do, so, re, are on black notes; 


and.) 2 iti, 9) mise Wola are on white. 


This, without going farther, at once indicates that there should be - 
some difference of musical effect between these keys. And this 
conclusion will be more fully borne out when we consider the . 
place of these notes in the principal chords. 

In the key of A, the major chords (the tonic dominant and 
subdominant chords) have their end notes (i.e. the first and fifth 
in each chord) on white notes, while the middle note in each (the 
third) is on a black note. Hence, in playing in this key the end 
notes of the major chords will be relatively strong, and the middle 
note relatively soft. This of course gives a peculiar quality to 
the chord. 

On the other hand, in A} the end notes of the major chords 
fall on black notes and are softened, while the middle note falls on 
a white note and retains its strength. This gives a special quality, 
differing from the former, to the major chords of Ap. 

The different provision made for the major chords in the two 
keys is vejenesaueat to the eye in the ee diagram :— 


Stoney—On Equal Temperament upon Piano Music. 65 


Postrions oF THE Masor Corps In THE Krys or A.AND Ab. 


In the key of A the notes = 8 = 8 = iS 

of the major chords fall. | 2 2) ag | ae 
° | ° ° 

Nowe Car), 6 3 »o o ci Co mi 0) 

Dominant chord, . . . .| s0 ti re 

Sub-dominant chord, . . .| fa la do 
: 4 os 

In the key of Ab, they ER: A g| 34 

fall, 25 6 | 2S 

a =| I =| 8 | 


In the minor chords there is also a contrast, though less uni- 
form in these two keys.* 

All these circumstances betoken that the musical effect of the 
two keys should be different, and it only remains to inquire why 
the difference of effect which we have established tends towards 
brightness in the one key and towards softness in the other. 

This is undoubtedly in part, because the third or middle note 
of a major chordt is the source of sweetness in the chord, while 
the end notes are the sources of its strength. In each of the 
major chords of the key of Ab, this source of sweetness is slightly 
reinforced as compared with the other notes of the chord; while 
in the key of A, the middle note falls below the others in intensity 
and richness. 

We may also connect it with the mysterious, but undoubtedly 
real, effects which the several notes of a scale produce on the 
mind when once the scale has become firmly established in the 
ear. These, when occurring in slow music, may be stated to 
be (following nearly the description of them given by the Sol- 
faists) :— | 


* The contrast of the minor chords attains uniformity in the keys of EK and Ep. 

+ In minor chords, the middle note appears to be the source of the greater 

piquancy which we perceive in minor chords; and in the key of A, and still more 
in the key of E, this element is relatively stronger than in the keys of Ab and Eb. 


66 Scientifie Proceedings, Royal Dublin Society. 


: | Bue 2 Prevailing artistic character , 
In Major Keys. SOR) in In Minor Keys. ° 
Aa slow Music. : 
la ough etic, tea chen ected eRe RCOnIC’ 
ti BY ede cil) Sie Rielan vee alee nelsupertonics 
(bhe tonic, sss) eed The firm note, . . . .| The mediant. 
The supertonic,. .| re The hopeful note, . . .j| The sub-dominant. 
The mediant, . .| mi The gentle note, . . . | The dominant. 
The sub-dominant, fa The solemn note, . . .{| The sub-mediant. 
The dominant, . .| so The strong note, 
si The submissive note, . .| The leading note. 
The sub-mediant, . | la The sorrowful note, 
The leading note, .| ti The sensitive note, . 


No single word will convey the variety of impressions made 
upon the mind by each note, but the impressions made by each 
form a natural group, and an attempt is made in the above 
Table to indicate one of the central members of each group. It 
however requires considerable modification when the music moves 
rapidly. 

Now observe that in the key of Ab it is the firm note, the 
hopeful note, the solemn note, and the strong note, which are 
softened by falling on black keys; while on the other hand the 
gentle note, the sorrowful note, and the sensitive note, are re- 
latively emphasized ; and this, taken in conjunction with what has 
been stated above, will abundantly account for the gentle liquid 
effect which can be produced in so striking a manner by this key. 

The key of A stands in contrast to this. Here the: gentle, 
sorrowful, and sensitive elements of the music are placed in the 
background, while prominence is given to the firm, hopeful, solemn, 
and strong elements. Hence A major, and its allies D and H, 
are eminently the keys for powerful, rousing, and joyous effects 
on the piano. 

It would be tedious to go through the details of applying this 
method to all the major keys, and it is less necessary as it is easy 
for the reader to satisfy himself that this method of treatment - 
will give a tolerably good account of the peculiar effect of each 
upon our emotions. 

In treating minor keys it will have to be remembered that la, 


Stonsy—On Equal Temperament upon Piano Music. 67 


the sorrowful note, is now the tonic (see Table on p. 65) ; alter 
which come in order ti, do, re, mi, and fa, exciting nearly the 
same sentiments in our minds as the notes of the same names in 
the major mode. So is absent, and in its place we have si, the | 
leading note of the new tonic, the impression on the mind pro- 
duced by which may be described as prevailingly submissive. It 
will be anticipated from these data that each minor key should 
produce a mental effect closely allied to that of its relative major, 
and this quite accords with experience. 
: On the other hand, the general effect of a onic minor is usually 
broadly contrasted with that of its major, in consequence of its 
being three removes off, and the effect which attaches intrinsically 
to the new key, on account of the additional flats in it, in some 
cases contributes sensibly to the peculiar effect which modulation 
into the tonic minor produces, although the main part of the 
effect of a tonic minor is, of course, relative and not intrinsic. 
The augmentation of the effect produced in this way is most 
felt where the intrinsic effect of the new key is in consonance 
with the natural effects produced by the minor mode. To see 
this, compare a modulation from A major to A minor, in which 
case there is little or none of the augmenting effect here spoken 
of, with a modulation from F major to F minor, in which it is 
conspicuously present. 

It will be sufficient to give one application of these srsimattglicg 
to minor keys, and as in dealing with major keys I endeavoured to 
take the most conspicuous example, I will here take one that is less 
prominent. In Beethoven’s universally known sonata with the 
Funeral March (Op. 26), a marvellous effect, unusually stately and 
self-contained as well as solemn, is produced by the opening 
phrases of the March. To this effect the key which Beethoven 
selected has contributed. It is not only the tonic minor of the 
preceding movement, but it is Ab minor, the key in which do, fa, 
and si are on white notes, and therefore emphasized in comparison - 
with the other notes, unconsciously to the performer. These are 
the firm, solemn, and submissive notes, and their being so em- 
phasized appears to contribute to the peculiar effect of the opening 
passages of the piece. The attitude of firmness thus established 
is made to grow within the mind of the hearer by that form otf 
insistent composition of which Beethoven was such a master, 


68 Scientific Proceedings, Royal Dublin Society. 


and is supported by the keys through which:the music is next 
successively led. The effect is increased by first passing from 
Ab minor to its relative major, viz. Cb, which differs from the 
minor by omitting the submissive note. After this it passes into 
the tonic minor of Cb, viz. B minor, a powerful key, and thence _ 
into its relative major, the key of D, thus reaching by steps of 
ever-increasing strength that which is perhaps the most powerful 
of all the keys on the piano. When this effect has been thus 
made to culminate, the prolonged repetition of one of the chords of 
minor thirds, and the sudden drop upon the original key through 
its fa—the most desolate of all notes—produces on the mind of. 
the hearer a mixed feeling of pain, settled gloom, and deter- 
mination, befitting the subject of the piece. Then follow other 
effects which we need not follow. These modulations would be 
impossible except on an instrument tuned on the system of equal 
temperament, or one closely approximating to it. . 

Finally, and to this I would particularly request attention, a 
~ complete corroboration of the foregoing method of treatment can 
be had by transposing very simple slow movements into the key 
of C major or A minor, as the case may be, taking care to finger - 
so as to soften the notes which in the original key fell upon black 
notes. In this way an artificial imitation of that key may fairly 
well be produced. The experiment succeeds best when the key 
imitated is one with flats, probably because the effect of such keys 
is easily brought out in very slow movements. For instance, 
F minor can be thus imitated. This observation appears to supply 
a satisfactory confirmation of the views which I have ventured to 
submit to the Society. 

The effects of different keys en have heen the subject of 
investigation in this Paper are, of course, peculiar to the piano. 
They are either not met with or are quite different on the organ, 
and in an orchestra. Any effects of the kind observable on the 
organ are probably to be attributed to the tempering, and have | 
no such connexion with black and white notes as on the piano; 
and in an orchestra any special effect of a particular key which the 
ear observes must be the complicated resultant of the peculiarities 
of many instruments, unless when (as it probably sometimes is) it 
is simply due to an association established in the memory of the 
hearer by the familiar experieng: of the effect of that key on 
the piano. 


Enyeoen | 


XIV.—A GEOLOGIST’S CONTRIBUTION TO THE HISTORY 
OF ANCIENT INDIA, BEING THE PRESIDENTIAL 
ADDRESS TO THE ROYAL GEOLOGICAL SOCIETY 
OF IRELAND. By PROFESSOR V. BALL, M.A., F.R.S., 


[Read, March 19, 1883.] 


Ir has devolved upon me,. somewhat out of the ordinary course, 
to deliver to you an address at the commencement of my term of 
office. The ill health of the late Professor Leith Adams precluded | 
his addressing you last year, and the duty was undertaken by the 
Rey. Dr. Haughton, whose long connexion with this Society ren- 
dered it particularly fitting that he, who for many years has been 
its principal stay and supporter, should be our President on the 
occasion of the celebration of our fiftieth anniversary. 

Having completed one year of office he has resigned, and pro- 
posed my election as his successor. This proposition having been 
adopted by the Council, and ratified by the Society at large, I find 
myself placed in this honourable position at a period when my 
service to the Society has been but of short duration, and my con- 
nexion with the progress of geological research in 1 Ireland of still 
less mature age. 

I have to thank you very sincerely for the high honour you 
have conferred upon me. It is a source of extreme gratification to 
me to find myself enrolled on the now long list of Presidents of 
. the Royal Geological Society of Ireland. Since that first meeting 
of the Society, held in the Provost’s house in November, 1831, 
there have been periods of great prosperity, as necessarily there 
must have been, since so many men of distinction who have held 
office were active in the furthering of the objects expressly laid 
down at the time of incorporation.’ 


1 At a meeting held at the Provost’s house November 29, 1831, it was resolved :— 
“That the gentlemen present do form a society for the purpose of investigating the 
mineral structure of the earth, and more particularly of Ireland, to be called the Geolo- 
gical Society of Dublin, and that to promote this investigation the Society shall hold 
periodical meetings, collect books, maps, specimens, and other objects relating to geo- 
logy and mineralogy, arrange the collection in a museum according to the most approved 
classifications, publish papers and essays, and eontribute in every other possible manner 
to the progress of geological science.” —LHuwtract from Minute Book. 


70 Scientific Proceedings, Royal Dublin Society. 


Our Minutes, which have been carefully kept for the half cen- 
tury, and the attendance-books, which are still extant, contain a 
most interesting record of the past. We can learn from them that 
the subjects discussed at the evening meetings served to attract 
and bring together, at one time or another, all those who have felt 
an interest in the progress of geological research in Ireland. There 
were many, too, who were perhaps more directly identified with 
other branches of science; still, by their presence at the meetings, 
they conferred upon the Society a status and influence which were 
widely felt at the time. 

Looking down that roll of past Presidents, there may be seen 
the names of many men whose accomplished work has secured for 
them a world-wide reputation, and among them, perhaps, I may 
be permitted as a personal matter to refer to those to whose teach- 
ing and encouragement I owe it, that twenty years ago I adopted 
the career of a professional geologist. Drs. Haughton and Apjohn 
and Professor Jukes were my instructors here, and by Dr. Oldham 
I was inducted into the duties of an Indian field geologist. It is 
natural, therefore, that I should feel honoured at being appointed 
as their successor, and it will be readily understood that I experi- 
ence a very special gratification at being appointed to succeed the 
structor of my earliest youth—my father, who exactly thirty years 
ago, or in 1853, delivered the Presidential address. — : 

It would be wrong were I to conceal the fact that we are not 
now in a prosperous condition. The Society has seen better days, 
but let us hope not its best. Just at present, from whatever cause, 
possibly from superior attractions afforded by other branches of 
science, active interest in geology appears to exist only enone a 
limited number. 

We stand in need of more members who will not only, by their 
subscriptions, place the Society in an improved position as regards 
its means for meeting its requirements, but who will, by contribut- 
' ing Papers, enable us to produce a journal which, from its variety 
and originality, will continue to prove acceptable and useful here 
in Ireland, and will serve to increase the cone s reputation in 
distant lands. 

The machinery exists, and is now in active operation, for ex- 
changing our publications with those of the principal learned 
societies all over the world, and we have the testimony of our 


Barr—President’s Address to the Royal Geological Society. 71 


correspondents that our journal is acceptable in exchange for the 
publications of other societies, of which many possess a high 
intrinsic value. 

But those who have to provide the material for the journal are 
not unmindful that it falls short, not only of being what it ought 
to be, but even of what it might easily 8 if all geologists in 
Ireland would give their aid. 

We want a larger income to enable us to provide fitting illus- 
trations. Many Geological Papers require, in order to be intelli- 
gible, more or less costly illustrations, and writers of such Papers 
would, doubtless, be more willing than they are at present to use 
our journal as their medium of publication, were they assured that 
such illustrations could be given with their Papers. To a certain 
- extent our present association with the Royal Dublin Society en- 
ables us to produce the journal at a less cost than would be the 
case were we working single-handed; but in our straitened cir- 
cumstances we have hitherto been enabled to avail ourselves of 
this aid as regards illustrations to but a very limited extent. 

Those of our members who contribute with most regularity to 
the journal—and the list of them is not a long one—give the Society 
not only their best and most important Papers, for which they 
might obtain a wider publication elsewhere, but they also give 
Papers of minor importance, the professed object of which is to 
provide the Society with material for its meetings. 

This is, perhaps, a not altogether healthy state of things; a 
longer list of contributors, and fewer contributions from the same 
individuals, would indicate a wider basis of support. In purely 
provincial societies, whose existence is due to the exertions of a few 
energetic individuals, such is to be expected; but it behoves us all 
to do our utmost to place and keep this Metropolitan Society in a 
higher rank than is ordinarily attained by a merely provincial 
society. The Royal Geological Society of Ireland is entitled by 
its past history and reputation to the support of everyone interested 
in the geology of Ireland in particular, and of residents in Ireland 
who are interested in general geology, all of whom we call upon to 
contribute their aid in the directions above pointed out. 

No one has realized the Society’s state of affairs more fully 
than our outgoing President; he naturally feels anxiety for its 
future, while its existing condition ever presents itself to-him in 


02 - Scientific Proceedings, Royal Dublin Society. 


his capacity as Treasurer. As a means of quickening the public 
interest in our operations, and of aiding in the development of 
Ireland’s industrial resources, he has proposed a scheme to the 
Council, the outlines of which it is now my duty to announce 
to you. 

Dr. Haughton considers that the past history of the aioe 
which have been made to develop the mineral resources of Ireland 
affords a safe guide as to the particular directions in which that. 
development may be most profitably prosecuted. He accepts it as 
demonstrated by experience, which has been purchased at great 
cost, that the metallic ores occurring in this country—absence of 
suitable fuel, &c., being taken into consideration—are, with one 
notable exception, not of great present value. He further con- 
siders it to be the case that the prospect of profitable exploitation 
on an extended scale afforded by the coal-fields of Ireland is not 
very encouraging. 

There are, however, on the other hand, mineral resources as to 
the abundance and value of which there is no doubt whatever, and — 
to these he proposes that certain members of the Society should 
direct their particular attention, with the view of drawing up a 
series of reports or monographs which will, it is hoped, prove of 
practical commercial value. 

The scheme has so far advanced that the duty of preparing 
these reports has been allotted and undertaken as follows :— 


1. Paving Setts: Dr. Haughton. 
tm. Antrim Iron Ores: Professor Hull. 
ur. Slates: Professor O’ Reilly. 
tv. Ornamental Building Stones: Professor V. Ball. 


v. Cements: 
vi. Pottery Clays: Baia ibe 


The co-operation of all whose positions anid opportunities may 
enable them to give aid in the way of statistics or suggestions in 
reference to these subjects is earnestly solicited, and all aid so 
afforded will be duly and thankfully acknowledged. 

We hope to show by these reports that, while on occasions we 
may occupy ourselves with questions of a more or less abstract 
nature, we are not unmindful of what we conceive to be our duty 


Bati—President’s Address to the Royal Geological Society. 73 


in respect to the application of scientific treatment to practical 
subjects. | 

In support of the statement made above as to the commercial 
value of some of the productions which have been enumeérated, 
reference need only be made to the large export trade which is 
done in Antrim iron ores; to the granite setts and ornamental 
granites which are exported from Newry, the former having been 
_ sent as far as Chicago, and the latter to Bucharest, and it may be 
added as being, perhaps, still more noteworthy, to Glasgow. The 
roofing slates of Ireland are not as yet by any means so largely 
employed as they deserve. I say this while fully conscious that 
they sometimes have defects which militate against their universal 
employment. 

Every resident in this city is aware that there are here in 
Dublin a number of chemical works engaged in the preparation 
of manures, bleaching powders, acids, &e. Although I know it is 
not the case in all, still at one of these works I found recently 
that no one of the substances of mineral origin which were used. in 
. these manufactures was the product of Irish soil. 

As might be expected, all the metal-work of the machinery 
and the lead of the acid vats had been imported. The phosphates 
were from South Carolina and Cambridgeshire. The pyrites from ~ 
Spain, after burning it, is reshipped to Swansea, where it is treated 
in the wet way to extract a small percentage of copper present in. 
the ore. ‘The manganese and the salt were also imported, and so 
were the large stone slabs used in the construction of the acid vats. 
Nay, more, the very limestone used in the manufacture of bleach- 
ing-powder comes from England, although Ireland is so especially 
a limestone country ; and, in the Co. Antrim, possesses chalk of 
exceptional purity, which is, to some extent, exported from Belfast 
to England, to return, perchance, as bleaching-powder, for the use 
of the linen works. 

Nearer at hand to us, at Skerries, I am informed, that a lime- 
stone of good quality is obtained; yet neither it nor the Temple- 
more limestone, also well suited to the purpose, are used at the 
particular works I refer to, though they are at others. 

The, as yet, unallotted subjects upon which we hope hereafter 
to publish reports, namely, the cements and the pottery clays, are 
certainly not of least importance. The materials are known to 


74 Scientific Proceedings, Royal Dublin Society. 


exist, and probably will be found in some quarters where they have 
not as yet been discovered. There seems to be every prospect of 
cements being more extensively used in the future than they have 
been in the past, and it is for the benefit of our buildings, no less ~ 
than for that of the industry itself, that a cheap local supply 
should become abundant. 

As for pottery clays, Belleek affords ample testimony of the 
presence of suitable materials, and the capabilities of native talent. 
Why that particular industry has not yet proved commercially 
successful I cannot say—it has certainly deserved to be so. 

I shall not further encroach now upon these subjects, which 
belong to the forthcoming reports, and will, no doubt, be discussed 
in them. Nor shall I enter upon any discussion as to the political 
questions which influence, in a superlative degree, the develop- 
ment of this country’s industrial resources. ; 

No fact is more generally acknowledged than that capital is 
sensitive. Hach possessor of it illustrates this truth by the manner 
in which he makes his investments. He may make mistakes, and 
he may send his capital to countries of which he knows nothing 
whatever, but he does not ordinarily invest his property in a 
country while he knows it to be in a condition of unrest. 

Circumstances, it is to be hoped, will bring about a condition 
of rest and renewed confidence here, and, in the meantime, we 
purpose preparing information on the above subjects, which will 
serve to indicate directions in which capital, when available, may 
be invested with the best prospect of future profit. 

A question has informally arisen among some of the Members 
in reference to the circumstances under which we at present hold 
our meetings, whether we should not be in a better position as 
regards the accession of new and active interest of old Members, if 
we had a more distinct local habitation, with our own library and 
so forth. But this question was, to the best of my belief, fully 
decided some years ago by circumstances which, while the Society 
regretted, it could not control. There are, probably, few younger 
Members of the Society than myself here present, and so I will not 
say more on a subject of which most of you know more than I do. 
But this may be said as regards the present, we don’t know how 
far our orbit of revolution as an independent body is from its com- 
pletion. Fifty-one and a-half years ago we started on our career 


Barr Geologist’s Contribution to the History of India. 75 


as a satellite of the Royal Irish Academy; we are now in close 
proximity with another body, but whether we shall merge into it, 
or on the conclusion of our period be re-absorbed by our original 
parent, time only can determine. “Having entered, however, on 
the second half-century of our existence as an independent body, 
let us hesitate before we take any step which may hasten our 
reaching a condition of nirvana, as our doing so would have one 
effect, among others—it would deprive posterity of the supreme 
gratification of celebrating our centenary. 

As on an occasion like the present some latitude is permis- 
sible in the selection of a topic, I have chosen the following as 
the special subject of my address :— 


A Gzoxoaist’s ContTRIBUTION To ‘THE History or ANCIENT 
Inpia, 


Being an attempt to identify the sources whence the mineral produc- 
tions were derived, which are mentioned by the Historians of 
India from the earliest times to the close of the eighteenth century. 


Tue subject of this Paper first attracted my attention in connexion 
with the preparation of the accounts of the diamonds and gold 
of India, read before this Society in the year 1880. Subsequently, 
_ when collecting materials for my volume on the Economic Geology, 
I found that there were many obscure historical notices upon which 
our modern knowleflge of the geology of that country was capable 
of throwing much light. Although some of the translators and 
critics of the ancient writings, which afford the principal part of 
my data, have sought to illustrate their authors’ meanings by re- 
ferences to'the results acquired by the systematic examination of 
the mineral resources of India in recent times, still there is often 
a considerable amount of vagueness and inaccuracy in these refe- 
rences, and, so far as I can ascertain, there has not as yet been 
published a comparative and categorical analysis of the numerous 
allusions to the mineral resources of India, which are to be found in 
writings belonging to the period extending from the earliest times 
of which any records are extant up to the close of the eighteenth 
century. 
SCIEN. PROC., R.D.S.—VOL. IV. PT. I. H 


76 Scientific Proceedings, Royal Dublin Society. 


Much has been done in the matter, however, by Mr. King, in 
his several masterly works on precious stones; but the mode of 
treatment here adopted differs from his in being primarily based 
on our .present knowledge of the mineral resources of India. 
Had all the data now available on that subject been before him 
there would have been little new for discussion 1 in such a Paper 
. as this. . | 
The facilities which I have enjoyed for consulting auithowtien 
- both in Calcutta and here in Dublin, in the rich treasury of rare 
volumes in the library of Trinity College, have enabled me to 
present a much longer list of writers than would have been pos- 
sible had the field of research been limited to but one of these 
sources. 

Two methods of employing the collected facts were open to 
me—either to arrange them under subjects or under authors’ 
names: the latter, as it presents a general view of the development 
and increase of knowledge, has been adopted. It is not without 
the manifest objection that the same subject crops up again and 
again in a disjointed manner; but if the facts had been arranged 
under the heading of subjects, the communication would have 
taken the form of a treatise on Hconomie Geology of India, 
which would scarcely be a suitable one for such an occasion 
as the present. 

_ The earliest traders in Indian commodities, of whose pr oceedings 
we have any record, were the Egyptians. According to Le Normant,! 
the bas-reliefs of the temple of Deir-el-Bahari at Thebes represent 
‘the conquest of the land of Pun under Hatasu. “In the abun- 
dant booty, loading the vessels of Pharaoh for conveyance to the 
land of Egpyt, appear a great many Indian animals and pro- 
ducts not indigenous to the soil of Yemen—elephants’ teeth, gold, 
precious stones, sandal-wood, and monkeys.” 

Again,” ‘The labours of M. de Bohlem (Das Alte. Indien; — 
vol. i. p. 42), confirming those of Heeren, and in their turn con- 
firmed by those of Lassen (Ind. Alt. ii. p. 580), have established 
the existence of a maritime commerce between India and Arabia 
from the very earliest period ‘of the annals of humanity.” The 


! Hist. Anc. de L’Orient—English edition, vol. ii. p. 299. 
7 Us Go BIL. 


Batt—A Geologist’s Contribution to the History of India. 77 


principal commodities imported from India were gold, tin, precious 
_ stones, ivory, &e. 

In the Mosaic period (1491-1450, 3.c.), too, precious stones, 
which were to a great extent a specialty of India and the neigh- 
_ bouring countries, appear to have been well known, and were 
already highly valued. It is probable that some of the stones 
in the breastplate of the high priest may have come from the far 
East. The emerald, however, if then known, was probably de- 
rived from a mine in Egypt, to which reference will be made ~ 
hereafter. At the same time there are grounds for believing that 
the word so rendered (Exod. xxviii. pe Ezek. xxvii. 13) may not 
be correctly translated. 

The next traders in Indian products were the Phoenicians, who 
for a time carried on their commerce with the ports of Aden, 
Cana, Haran, Yemen, and Muza, to which the commodities of 
India were brought for exchange by Arabian, and possibly 
Indian and Cingalese, ships. : 

Somewhere about 1015 B.c., Solomon joined Hiram, King of 
Tyre, in a nautical and commercial venture of a more ambitious 
' nature than had previously been attempted, “For the king had 
at sea a navy of Tharshish with the navy of Hiram: once in three 
years came the navy of Tharshish, bringing gold and silver, ivory, 
apes, and peacocks.”’? 

These ‘ships were the first which had ever doubled the southern 
parts of Arabia arfd then sailed straight for India. ‘The first port 
in that country of which we have any mention is Ophir. The 
vessels were built of timber from Judea, at Hlath and Erziongeber, 
and they were manned by Phenicians. They were called “ships 
of Tharshish,” because they were of the same form and build 
as those which had previously been employed in the trade to. 
Tharshish, situated, as is now generally known, in the south of 
Spain. 
It is needless, perhaps, to discuss here the many views which 
have been put forward as to the identity of Ophir. Lassen? says 
it was on the site of Abhira, on the western coast, adjoining the 
province of Guzerat. Others locate it in Ceylon; but General 


1 1, Kings, i. 22; also see ix. 28., &. 
2 Indisch. Alter., vol. u. pp. 584 Boze 
HZ 


73 Scientific Proceedings, Royal Dublin Society. 


Cunningham’s researches place it also in the Gulf of Cambay. 
The name Ophir, or Sophir, he identifies with Sauwvira, a name | 
derived from that of the ber-tree (Zizyphus jwuba), which is 
plentiful in that region. 

Since gold, silver, ivory, apes, and peacocks are productions 
of India—and the Hebrew name for the last is derived from tukki, 
an Indian word—there is internal evidence that Ophir was situated 
in that country. It is not likely to have been in the more Eastern, 
Burmese, or Malayan countries, where, it must be admitted, the 
same commodities might have been obtained.’ 

. Passing the notices of precious stones to be found in the 
biblical books written during the course of the next five centuries, 
we find that Herodotus (fifth century B.c.) gives us some insight 
into the nature and extent of certain Indian mineral productions.. 
Babylon obtained precious stones and dogs (probably Thibetan 
mastiffs) from India.’ 

In the enumeration of the nations and tribes which paid tribute 
to the Persian monarch, Darius, the Indians alone, we are told, 
paid in gold, all the others. paying in silver. The amount of this 
gold was 360 Eubeic talents = £1,290,000. Herodotus pointedly, © 
moreover, speaks of India as being “rich in gold”;* and he 
relates the famous and widespread fable of the gold-digging ants, 
the origin of which has been fully ascertained, as I have already 
described in these pages.’ I shall only add now that the “ horns 
of the gold-digging ants,” referred to by Pliny and others, were, 
probably, simply samples of the ordinary pickaxes used by the 
miners. In Ladakh, and, probably, also in. Thibet, these imple- 
ments are made of the horns of wild sheep, mounted on handles 
of wood. 


1 Anc. Geog. of India, pp. 496-7 ; and 560-62. 

2 Mr. Eastwick estimates that the gold which reached Solomon by way of the 
- Red Sea amounted to 3,330,000 Ibs. in weight, or 160 millions sterling. In his 
Paper entitled, ‘‘ Gold in India,’’ it may be .added, he is inclined to locate 
Ophir in the Malabar country, in the neighbourhood of the gold-bearing regions of 
‘Southern India. 

3 Herodotus, i., 192. 2 (5 Os tbl, IOS. 

° These Proceedings for 1880. The fable has been shown by Sir Henry Rawlinson 
and Dr. Schiern to have originated in the peculiar customs of the Thibetan gold miners, 
which would appear to be the same at present as they were in the time of Herodotus. _ 
The name ‘‘Ant”’ gold was possibly first given to the fragments of gold dust brought 
from Thibet on account of their shape and size. 


Bari—A_Geologist’s Contribution to the History of India. '79 


The portion of India conquered by Darius was probably 
situated chiefly to the north-west of the Indus. The Indus itself, 
as well as some of its tributaries, is known to be auriferous. 

_ Many commentators on the above and other references by sub- 
sequent authors to the existence of gold (and silver), as indigenous 
products of India, object that mines of these metals are or were 
not known to exist in India. Thus Lassen says: “If the ancients 
speak of abundant gold in India, it is either only a false amplifica- 
tion of the early and true account of Northern India, the country 
of the Dards, between Kashmir and the Upper Indus, or a false 
conclusion, from the fact that the Indians used much gold for orna- 
ments and other purposes.” Heeren, like Lassen, alludes doubt- 
fully to Pliny’s statement (vide postea) as to the existence of 
abundant gold and silver mines in the country of the Narex: 
he attributes the quantity of gold which must have been. in 
Ancient India to commerce with other gold-producing countries, 
namely, Thibet and Burmah. He even suggests: that African 
gold found its way to India in early as well as it is known to 
have done in later times. 

Our most recent knowledge of India, however, affords evidence 
that the amount of gold derived from indigenous sources must 
have been very considerable before the alluvial deposits were 
exhausted of their gold throughout wide regions. 

When it is remembered that about 80 per cent. of the gold 
raised throughout the world is from alluvial washings, and when 
this fact is considered in connexion with the reflection that wide 
‘tracts in Australia and America, formerly richly productive, are 
now deserted, being covered with exhausted tailings, it can be 
conceived how these regions in India, and there are very many 
of them, which are known to be auriferous, may, in the lapse 
of time, after yielding large supplies of gold, have become too 
exhausted to be of much present consideration. 

More than this, however: recent explorations have confirmed 
the fact, often previously asserted, that in Southern India there 
are indications of extended mining operations having been carried 
on. there. 

Evidence exists of the most conclusive kind of large quantities 


1 Asiatic Nations, yol. iii. pp. 408-9, 


80 Scientific Proceedings, Royal Dublin Society. 


of gold having been amassed by Indian monarchs, who accepted 
a revenue in gold dust only, from certain sections of their subjects, 
who were consequently compelled to pene months of every 
year washing for it in the rivers. 

The already-quoted facts taken from the pages of the Bible 
and Herodotus must be accepted as evidence that gold was an 
export from India, and that to so large an extent, that the sug- 
gestion that it was first imported may be safely rejected. A 
large amount, very probably, reached Northern India in the 
course of trade from Thibet; but it is incredible that the vast 
stores which, as will be shown on a future page, were in the 
possession of the princes of Southern India about 600 years ago, 
was, to any considerable extent, derived from extraneous sources. 

Much uncertainty exists as to the date of the famous Indian 
epic known as the Ramayana. By Wilson, however, it is sup- 
posed to have been written about 300 s.c.; but it refers to a time 
probably contemporaneous with Solomon. It represents India as 
abounding at that early period in wealth, which we cannot but 
conclude was mainly of indigenous origin. In the description of 
the capital town of Ajodhya, as quoted by Heeren,' we are told 
“it was filled with merchants and artificers of all kinds; gold, 
precious stones, and jewels were there found in abundance; every- 
one wore costly garments, bracelets, and necklaces.” Again, 
“The present made to Sita consisted of a whole measure of gold 
pieces and a vast quantity of the same precious metal in ingots: 
golden chariots, golden trappings for elephants and horses, and 
golden bells are also noticed as articles of luxury and magni- 
ficence.”” 

The Indika, by Ktesias, the Knidan (398 3.c.) was the first 
regular Greek treatise on India. The fragments of it which have 
been preserved by Photios and other writers have recently been 
brought together and carefully annotated by Mr. M‘Crindle, to 
whose work I am indebted for the following extracts bearing 
upon our subject. Ktesias’s knowledge of India was all derived 
at; second-hand from persons he came in contact with at the 
Persian Court, where he resided under Darius and his successor, 
Artaxerxes Memnon. 


1 Asiatic Nations, vol. 11., chap. ii. p. 355. 


 Barr—A Geologist’s Contribution to the History of India. 81 


Ktesias informs us that there is a lake in the country of the 
Pygmies upon the surface of which oil is produced. The Pygmies 
are described as being covered over with long hair. A tribe cor- 
responding to this description has been reported to exist in Upper 
Burmah, and there also are the only largely productive petro- 
leum deposits, which, moreover, we know to have been worked since 
the earliest times.’ Silver also was and is found in this region. 

_ This report, however, it should be clearly understood, requires 
very distinct confirmation before it can beaccepted. It is probably 
merely a fable; but the existence of sources of rock-oil and silver , 
in Upper Burmah is noteworthy, no other region being known to 
produce both, though silver is found in many localities in India, 
and rock-oil in Assam and the Punjab. 

The elektron or amber of Ktesias, a product of trees, was 
certainly shellac, and the insects found with it, which yielded a 
red dye, were lac insects. As, therefore, this amber does not 
properly belong to our subject, I shall say no more about it at 
present. ; 

Gold, we are told, was only obtained on certain “ high-towering 
mountains” inhabited by the griffins—a race of four-footed birds, _ 

about as large as wolves, having legs and claws like those of the 
lion, and covered all over the body with black feathers, except 
only on the breast, where they are red. Now, if we omit the 
word “birds” in the above, and for “ feathers”’ read “hair,” there 
is no difficulty in recognising the griffins as the Thibetan mastiffs, 
which are powerful, hairy, often black-and-tan-coloured dogs, 
specimens of which, by the way, appear to have been taken to the 
Persian Court as examples of the gold-digging ants, which were 
first described by Herodotus. We may, I think, therefore, justly 
conclude that the locality referred to was situated.in Thibet. 

Gold was also said to be obtained from a spring, being drawn 
from it in earthen pitchers in which it congealed. This story is 
obviously founded on the casting of ingots; but I cannot see that 


1 Kconomic Geology of India, p. 138. 

2 Herodotus (i. 192) tells us, as pointed out by Le Normant, that India supplied 
Babylon with “ precious stones and large dogs; and so great was the passion for the 
latter, that Tritanteechmes, Satrap of Babylon under the Achemians, had set apart 
four cities or large villages, exempted from all other taxes, on condition of maintaining 
his dogs.” —Manual of the Ancient History of the Kast, vol. i. p. 496, 


82 Scientific Proceedings, Royal Dublin Society. 


Lassen’s view, that it shows that the Indians knew how to extract 
gold from ores, follows, since it may merely refer to the melting of 
alluvial gold dust. 

Silver is said to occur also in the above-mentioned country of 
the Pygmies, upon which Lassen remarks that silver is only known 
to occur in Ajmir. It has, however, a much wider distribution, as 
I have shown in my “ Economic Geology”; but the only region in 
which it is regularly produced at present is Upper Burmah.! 

Tron is said to be found in the same spring or fountain as the 
gold; and Ktesias had two swords, made of Indian iron, given to 
him respectively by the King of Persia, and his mother. This 
iron consisted, I believe, of ingots of woofs or cast-steel, from which 
Damascus blades have been made since time immemorial.’ The 
power of iron to ward off thunderstorms, which is referred to by | 
Ktesias, suggests rather an early knowledge of the use of lightning 
conductors than of the properties of the magnet, which is the ex- 
planation offered by Baehr. 

The Pantarba is a kind of stone which, when thrown into the 
water, had the power of drawing together other stones of various 
colours to the number of 77. Ithas been suggested by Count Von 

‘Veltheim that this was some kind of opal, which, on being put 
into water, exhibited a rich play of colours. Upon this I can 
offer no opinion : no more probable supposition suggests itself to 
my mind. 

The sardine stone, the onyx, and other seal stones, are said to 
be found in certain high mountains. There is no further indica- 
tion of locality. Possibly, Oujein, in Malwa, or some of the other 
‘places where mines of Chalcedonic minerals occur, was intended. 

Evidence of various kinds exists that in the time of the Indian 
monarch, Asoka, about 300 B.c., the mineral resources of India were 
well known and were largely availed of. Stone architecture on a 
magnificent scale, which is still extant, bears testimony to the skill 
of the Buddhist stone-masons of a still earlier period. The elaborate 
carvings on some of these prove the excellence of the tools which . 
were employed; probably they were made of Indian steel or 
wootz. .'The famous Asoka monoliths of a later date, from 35 to 


1 Economic Geology, p. 234. : 
* The name wootz, according to Lassen, Indisch. Alt. (i. p. 239), is derived from 
the Sanskrit vag’ra, from two words signifying diamond and thunderbolt. 


Batt—A Geologist’s Contribution to the History of India. 88 


40 feet long, and about as many tons in weight, are, in their way 
too, remarkable, though not exhibiting such ornate designs. 

In z.c. 307, according to the Wahawanso, the King of Ceylon 
(or Lanka), Dewananpiatisso, ‘was installed, and shortly afterwards 
he sent an embassy to Asoka at Palibothra, the presents consist- 
ing of sapphires, lapis-lazuli, rubies, and eight varieties of pearls, 
which, we are told, rose miraculously from the earth and sea 
respectively on the auspicious occasion. Asoka’s return-gift con- 
sisted of golden and other ornaments, and as an especial rarity, 
“costly hand-towels, which to the last moment they are used (are 
cleansed by being passed through the fire) without being washed.” 

Now, with reference to the above, I venture to think that the 
translator has made a mistake as regards lapis-lazuli. ‘It has 
never been known to be a product of Ceylon. The word possibly 
means either the asteria (or star sapphire), or another blue mineral 
called iolite (or dichroite), both of which occur in Ceylon. In this 
connexion it may be interesting to note that, in some excavations 
made recently on the supposed site of Asoka’s throne,” there were 
obtained sapphires and emeralds, mostly broken into splinters, two 
pebbles of iolite, some beads of lapis-lazuli, coral, &c., and some 
imitation emeralds, made of glass. Lapis-lazuli, therefore, was 
possibly known in Asoka’s time, but probably it did not come 
from Ceylon, but from the mines in Badakshan, to be mentioned 
hereafter. | 

The hand-towels were most likely made of woven asbestos, a | 
substance which has long been known to occur in Kabul,? and may 
very possibly have reached India from thence. 

The work by Megasthenes (802 B.c.), entitled ra wera, no 
longer exists, except in fragments, which have been quoted by 
subsequent writers. These have recently been brought together 
by Mr. M‘Crindle from the pages of Strabo, Pliny, Arrian, 
Diodorus, &c. It is probable that these fragments represent only: 
a small portion of the whole work; but so far as they go, since 
the individual quotations by each of the authors are checked 
by those of the others, we are justified in the belief that the 


1 A History of Ceylon for Twenty-four Centuries, from p.c. 548: translated by 
Turnour, p. 70. 

2 Vide Proc. As. Society, Bengal ; May, 1881, p. 89. 

3 Heonomic Geology of India, p. 519. 


84 Scientific Proceedings, Royal Dublin Society. 


general facts related are as they were originally stated by Megas- 
thenes. 

The first statement bearing on our subject is taken from 
Diodorus’ :— 

“‘ And while the soil (of India) bears on its surface all kinds of 
fruits which are known to cultivation, it has also under ground 
numerous veins of all sorts of metals, for it contains much gold 
and silver, and copper and iron in no small quantity, and even tin 
and other metals, which are employed in making articles of use 
and ornament, as well as the implements and accoutrements of 
war.” 

Upon this I shall only here remark that the item of greatest 
interest is the tin. ven in Homeric times reference to this metal 
as coming from India is to be found in conjunction with the 
mention of e/ephas or ivory. The Greek name for it, kassiteros, is 
moreover said to be derived from the Sanskrit, kastira. That 
India produced tin in sufficient quantities for exportation is, I 
believe, most improbable. The tin which she did export pro- 
bably came to the Indian ports from the Malayan countries or 
Tenasserim. 

The fable of the gold-digging ants, already alluded.to as 
having been related by Herodotus, is quoted by Strabo and 
Arrian from Megasthenes. Arrian further also refers to the 
account by Nearchos,” who says that “he had not himself seen a 
specimen of the sort of ant which other writers declare to exist in - 
India, though he had seen many skins of them which had been 
brought into the Makedonian camp.”* But Megasthenes avers 
that the tradition about the ants is strictly true—that they are 
gold-diggers, not for the sake of the gold itself, but. because by ~ 
instinct they burrow holes in the earth to lie in, just as the tiny 
ants of our own country dig little holes for themselves; only those 
.in India being larger than foxes, make their burrows propor- 
tionately larger. But the ground is impregnated with gold, and | 
the Indians thence obtain their gold. Now, Megasthenes writes 
what he had heard from hearsay, and as I have no more exact 
information to give, I willingly dismiss the subject of the ant.” 


1 Ancient India, p. 31. 2 M‘Crindle’s Arrian, p. 217. 
3 These I believe to have been skins of the Thibetan mastiffs (or griffins), which, I 
understand, are still brought to India for sale. 


Batt—A Geologist’s Contribution to the History of India. 865 


Pliny, in his list of the Indian Races, which is believed to have - 
been mostly borrowed from Megasthenes, says:—‘‘ Next follow 
the Narez, enclosed by the loftiest of Indian mountains, Capitalia. 
The inhabitants on the other side of this mountain work extensive 
mines of gold and silver.” Capitalia may certainly be identified 
with Mount Abu; and although the highest authorities are divided 
as to the identity of the Narez, the mention of mines of gold and 
silver compels me to believe that the Nairs of Malabar were 
intended, as in Malabar and the neighbouring regions are situated 
not only the ancient gold mines which have attracted so much 
notice of late years, but there are also enormous ancient mines in 
the districts of Kadapah and Karnul from whence argentiferous 
galena appears to have been extracted, and from this ore silver 
was, very probably, obtained.' 

In another. passage in this list of Pliny we find the following 
statement :—“ Gold is very abundant among the Darde and silver 
among the Setz.’’ On this Mr. M‘Crindle remarks that the Sete 
are the Sata or Sataka of Sanskrit geography, which locates them 
in the neighbourhood of the Daradas. I was inclined to believe 
that the country of the Sete may have been the Wazir-i-rupi, or 
. silver country of the Wazirs, 7.e. Kulu, where angeniaforous galenas 
undoubtedly do occur. 

Colonel Yule identifies them, however, with the Sanskrit Sekas, 
and he places them on the Bannas, about Jhajpur, south-east from 
Ajmir. ‘There are extensive ancient mines from which galena 
was obtained near the Taragarh hill in Ajmir; but, so far as I 
can ascertain, there is no record of their having produced silver. 
Galena, known to contain silver, appears to have been mined for 
_ at Jodawas in Alwar, and at Jawar or Zawar in Udepur, but this 
latter locality was chiefly remarkable, indeed unique in India, for 
producing zine.” | 

Further on, in Pliny’s enumeration above alluded to, we meet 
the following passage :—‘“ Beyond the mouth of the Indus are 


‘1 Vide Economic Geology of India, p. 232. 

2 Todd’ (Rajasthan, p. 12, 504), has described this as being a tin mine, an error 
which has misled Lassen (Indisch. Alt., vol. i. p. 239), who states that the large pro- 
duction from this mine may account for the fact that the Indian name of tin, already 
alluded to on a previous page, was at so early a period spread throughout the western 
world. 


86 Scientific Proceedings, Royal Dublin Society. 


Chryse and Argyre, rich, as I believe, in metals. For I cannot 
readily believe, what is asserted by some writers, that their soil is 
impregnated with gold and silver. At a distance of twenty miles 
from these lies Crocala.”” This last, according to Mr. M‘Crindle, 
is identified with Karkalla, the district which includes Karachi; 
but Colonel Yule identifies the former two localities with Burma 
and Ardkan, as will be mentioned below in connexion with 
Ptolomey’s reference to the same subject. ) 

About the year 30 8.c. Dionysius Perigetes, in his ““ Oikoumenes. 
Perithesis,” gives a rough indication of the position of the region 
from whence the diamonds which at that time found their way to 
Europe were derived. The adamas, he states, together with beryl, 
green jasper, topaz, and amethyst, were found in the river beds of 
the country lying to the east of Mount Parapamissus (7. e. the 
Hindu Kush) and Ariana. Although some doubt may be felt in 
this instance as to the true meaning of the term adamas, its appli- 
cability to the diamond, when used by Manilius a few years later, 
is indisputable. This latter author flourished during the Augustan 
age (B.C. 31 to a.p. 14), but the exact date of his poem is not 
known. 

Puiny, a.p. 77.—In his Historia Naturalis, the industrious 
compiler Pliny has given an extraordinary amount of information | 
regarding precious stones and metals, a large proportion of them 
being of Indian origin. 

Reference: has already been made to those passages which 
appear to have been derived from the older authors, more parti- 
- cularly to those referring to gold. A locality, namely the Ganges, 
mentioned by Pliny (B. xxxiii., c. 21), may, perhaps, refer to 
known sources of the precious metal in the tributaries of the 
Upper Ganges. His remarks on the quantity of gold in India 
'(B. xxxiii., c. 21) are full of interest. 

Recenter iron, he says the best is made by the Sores ; some 
authors suppose them to have been an Indian tribe thane 
Sarhind, the modern Umbala District, but the balance of evidence 
is certainly in favour of their having been Chinese. The next 
quality is from Parthia. Elsewhere he says (B. xu. c. 8) that 
the Romans obtained steel, together with pearls, at Cape Comorin. 


1 Vide Latin Version, vv. 815 and 1107. 


Bati—A Geologist’s Contribution to the History of India. 87 


His account of the Murrhine on the whole bears out the view 
as to its nature, stated below on page 89, save that he records 
(B. xxxvii. c. 7) that “a person of consular rank, who some 
years ago used to drink out of this cup, grew so passionately fond 
of it as to gnaw its edges” —a fact not consistent with it being a 
substance having the hardness of the Chalcedonic minerals. 

- Regarding amber, he quotes the account by Ktesias, which, 
as has been shown, refers to shellac, and alludes to the fable of 
amber being produced from the tears of the meleagrides (guinea- 
fowl). Another statement of his which I.cannot explain is, that the 
Indians polish amber by boiling it in the grease of a sucking pig. 

Adamas.—Under this head the diamond appears to have been 
included, together with some other stones. “It is,” he says 
(B. xxxvii. c. 15), “the substance that possesses the greatest value, 
not only among the precious stones, but of all human possessions, 
a mineral which for a long time was known to kings only, and to 
very few of them.” Where, however, he refers toits hexangular and 
hexahedral form, he appears to have been alluding to some other 
mineral; but his mention of splinters as being used by engravers 
of other stones agaizi points to the true diamond. He says it 
could only be broken after being steeped in the blood of a he- 
goat. : 

Smaragdus.—Twelve varieties are mentioned (B. xxxvil., 
caps. 16, 17). Some of these may have been emeralds, espe- 
cially those of the third rank, which are said to have come from 
Egypt. This locality is considered to have been Mount Zalora, 
in Upper Egypt, which still produces emeralds, and was probably 
the only locality for them known by the ancients. With reference 
to some of the other varieties, I feel no little confidence in suggest- 
ing that they may have been jade, but this mineral is also 
included in his account of Jaspis. 

Beryls are said to be found-in India, and rarely elsewhere 
(B. xxxvii. c. 20). It is certainly true that they do occur in 
India, but I am unaware of their being now highly esteemed by 
the natives, as appears to have been the case in Pliny’s time. 

Opals, according to Pliny, were alone produced in India. Iam 
not aware of any known source of precious opal in India. His 
‘ reference is therefore, probably, to some of the common varieties. 
Want of space prevents me from further analysing Pliny’s 


88 Scientific Proceedings, Royal Dublin Society. 


catalogue, the more particularly as it does not add much to 
what is elsewhere given on previous pages. 

Tue Prripius or THE HrytHRmAN Sza (Cirea, a.p. 80-89 ?)— 
The author of this work, a Greek merchant, resident in Hgypt, is 
not known to us by name. His statements of the Indian export 
and import trade are given with a great deal of method and 
obvious accuracy. ‘The following extracts are from Mr. M‘Crindle’s 
translation. The principal ports mentioned are Barugaza, the 
modern Bharoch, on the Narbada; Barbarikon, on the Indus; 
Mouziris (Mangalore), and Nilkunda (south of Mangalore), both 
the last being on the coast of Malabar. First, as regards the 
exports: Indian iron and sword blades were exported from Arabia 
to Adouli in Africa. Indian iron is mentioned in the Pandects as 
an article of commerce, and the Arabian poets celebrate swords of 
Indian steel—as well they aga since the material of the famous 
Damascus blades was “ wootz,’’ which was manufactured in an 
obscure village in the Hyderabad territory.’ 

From the ports of Mouziris and Nilkunda gems in great . 
variety were exported; but these, it is expressly stated, were not 
produced in India, but were brought from Taprobane or Ceylon. — 
They probably consisted of the varieties of what we now call 
corundum, viz., sapphire, ruby, &e. 

Separately, the Adauac is mentioned as being oat from these 
ports, and it seems probable that under this title we may under- 
stand that diamonds, the production of Indian mines, are re- 
ferred to. 

From Barbarikon, on the Indus, a stone called caA\eavoc was 
exported. It has been suggested that gold stone or chrysolite was 
indicated by this name. I cannot think that this is likely to be 
correct. Chrysolite of value is not, so far as we know, a product 
of that region: more probably, as has been suggested by Dana, it 
was turquoise, or an allied mineral now called callianite. If this 
identification be correct, it probably came through Afghanistan 
from Persia—the most famous known source of it being at Amsar, 
near Nishapur in Khorassan. Its occurrence anywhere nearer is 
extremely doubtful.’ 

From Barugaza to Egypt vast quantities of ‘Ovuxi were 


1 Vide Economic Geology, p. 340. 2 Economic Geology, p. 4385. 


Batir—Inaugural Address to the Royal Geological Society. 89 


exported. They reached the seaport from Ozene:and Paithana, 
the modern Ujein in Malwa, and Paithan in Hyderabad. These 
are still known as the principal sources, among many, where 
pebbles of onyx and other Chalcedonic minerals are obtained from. 
the detritus of the Deccan basalt.1 The famous Movopivn, which 
fetched extravagant prices? in the Roman markets, was also 
obtained in Ozene and exported from Barugaza. 

Regarding the identity of this substance, Herman Miller, as 
quoted by Mr. M‘Crindle, remarks :—‘‘Six hundred writers emu- 
lously applying themselves.to explain what had the best claim to 
be considered the Murrha of the ancients, have advanced the most 
conflicting opinions. Now it is pretty well settled that the Murr- 
hine vases were made of that stone which is called in German 
flusspath (spato fluore”’). In spite of a desire not to augment this 
intolerable number of opinions, I must register an objection to this 
judicial decision of Professor Miller. Fluo’ spar happens to be, 
though so common a mineral in other countries, of the very greatest 
rarity in India, and there is no record of its occurrence in the 
Deccan basalts. It is, moreover, a mineral which, while it is sus- 
ceptible of being: made into ornamental objects, is, from its soft- 
ness, easily injured by wear and tear, and therefore possesses little 
- durability. 

On the other hand, at Ujein, a great variety of Chalcedonic 
minerals are found, and I therefore prefer to follow those of the 
six hundred writers who have identified one or other of its varieties 
_ with the ancient murrha. At the present day cups and vases of 
carnelian, agate, &c., are obtainable in Bombay; and I think it 
most improbable that the modern Afiks, or lapidaries, who are the. 
direct descendants of those who made the murrhine cups 2000 . 
years ago, ever saw, much less worked, the mineral called fluor spar. 

Another argument in support of this identification has been 
urged by some writers: it is that stone cups and vases, and frag- _ 
ments of them which have been obtained in excavations at Rome, 
have, on examination, proved to be of this material. None of fluor 
spar are recorded. . 


1 Economic Geology of India, p. 502, where numerous references and a full account 
of the trade will be found. 

2 Nero gave for one 300 talents, =£08,125. They were first seen at Rome in the 
triumphal procession of Pompey. 


90 Scientific Proceedings, Royal Dublin Society. 


The Sargepoc was, we are told, exported from Barbarikon. 
If this were the true sapphire of modern times, its export, from 
the most northern port, and, therefore, furthest from the recog- 
nised sources of the stone, would in itself be difficult to explain. 
It has been, however, clearly shown by King [Precious Stones] 
and Dana [Mineralogy] that the Sémpepoc of Theophrastus, 
Pliny, and Isidorus, &c., was what we now call lapis-lazuli. 
For Pliny says, “ Sapphewos ceruleus est cum purpura, habens 
aureos sparsos.”’ Now lapis-lazuli is characterised by having 
scattered through the blue mass small crystalline particles of 
golden-coloured iron pytites. 

As further evidence in favour of this interpretation, there is 
the fact that there are very ancient mines of lapis-lazuli at 
Firgamu in Badakshan (not Beluchistan, as has been incorrectly 
stated by some writers), and it might very easily have been brought 
by caravans through Afghanistan to Barbarikon. The mines 
alluded to are described by Wood in the account of his journey 
to the Oxus, and both Marco Polo and Tavernier refer to the 
occurrence of the mineral in that region. 

Captain Hutton, in 1841, found it on sale at Kandahar. He 
mentions several places in Afghanistan where it was said to 
occur.’ | 

The YaxwvGoce, on the other hand, which was exported from the 
southern ports Mouziris and Nilkunda, is thought by some to 
have been the sapphire, as also was the hyacinthus of Pliny 
(xxxvil. 44), and its variety the asteria (id. xxxvii. 49). The 
- yakut, as the name is now understood in India, is either a ruby, or 
the inferior spinel (more properly called /aa/), or even a garnet. 
According to Salmasius, quoted by Mr. M‘Crindle, the Yaxwv@oc is 
the ruby, while according to Solinus it would appear to be the 
amethyst. ‘This is a point on which Indian geology throws no 
certain light, as neither rubies nor sapphires appear to have been 
indigenous products.” 

In the Persian work on precious stones quoted hereafter, it will 
be seen that in the thirteenth century the same generic name was 
applied to the ruby, sapphire, and other varieties of corundum. 


1 Vide Keconomic Geology of India, p. 528. 
* It should be stated that there have been recent discoveries. of sapphires in the 
Himalayas, but there is no evidence that they were ever found there before. 


Batt—A Geologist’s Contribution to the History of India. 91 


With reference to the imports which are of interest as indicat- 
ing the requirements, if not of the whole of India, at least of that 
portion of Western India into which they were carried, we find 
the following enumeration :— 

Silver: Costly plate, from Egypt to Barugaza. 

Gold and silver coins, from Egypt to Barugaza. 

Gold bullion, from Arabia to Barugaza. - 

Arsenic, from Egypt to Mouziris and Nilkunda. 

Tin, from Egypt to Mouziris and Barugaza. 

Lead, from Egypt to Mouziris and Barugaza. 

Antimony sulphide, from Kgypt to Mouziris and Barugaza. 
Copper, from Egypt to Mouziris and Barugaza. 

The import of silver plate at this early period is remarkable. 
Whether it has been kept up in modern times, so far as the require- 
ments of the natives are concerned, I cannot say, but the other 
substances are still largely imported. In four years recently, for 
instance, upwards of 200 tons of arsenic, in the forms of white 
arsenic, orpiment, and realgar, were imported; and the antimony 
sulphide, called swrma by the natives of India, is largely used for — 
anointing the eyes. 

XovoodBoe was also exported from Hgypt to all four ports. 
It appears to be tolerably clear that this mineral was not our 
modern chrysolite, but was the topaz, while the topazion of Pliny 
was in part at least chrysolite, as he says it yielded to the file and 
wore with use; but his mention of a statue, 4 cubits high, which ~ 
was made of it, mdicates a crystal of a size quite unheard of: pro- 
bably this was either beryl or jade. 

Protomey (a.p. 140-160). Diamonds.—The Adamas river of 
Ptolomey, according to Lassen’s analysis of the data, was not 
identical with the Mahanadi, as I have suggested in my “ Economic 
Geology,’’! but with the Subanrikha, which is, however, so far as we 
know, not a diamond-bearing river, nor does it at any part of its 
course traverse rocks of the age of thoge which contain the matrix 
of the diamond in other parts of India. This Adamas river was 
separated from the Mahnada (7.e. Mahanadi) by the Tyndis and 
-Dosaron; the latter, according to Lassen, taking its rise in the 
country of Kokkonaga (i.e. Chutia Nagpur), and’ to which the 
chief town, Dosara (the modern Doesa), gave its name. But, 


' Economic Geology, p. 30. 


SCIEN. PROC. R.D.S.—VOL. IV. PT. Ile I 


92 Scientifie Proceedings, Royal Dublin Society. 


according to this view, the Dosaron must have been identical with 
the modern Brahmini, which, in that portion of its course called the 
Sunk (or Koel), included a diamond locality. I cannot regard this 
identification as satisfactory, as it does not account for the Tyndis 
intervening between the Dosaron and Mahnada, since, as a matter 
of fact, the Brahmini and Mahanadi are confluent at their 
mouths. 
Lassen, however, identifies the Dosaron with the Baiturnee, and 
the Tyndis with the Brahmini. This destroys the force of his 
remark as to the origin of the name of the former, since at its 
nearest point it is many miles distant from Doesa. 

Another locality of Ptolomey’s, said to be situated on the 
Ganges, in the country of the Sabares, may, perhaps, be identical 
with ‘Tavernier’s Soumelpour on the Koel; it was situated some 
miles distant from the Ganges. Wherever it was, it produced 
most diamonds. 

A third locality mentioned by Ptolomey has been variously 
identified with Sambalpur and Weiragarh' in West Gondwana, 
the position of which last was not correctly known to either Ritter 
or Lassen, though the fact of the existence of diamond mines there 
had been recorded by Ferishta and Abdul Fazl. 

Ptolomey stated that Ceylon produced the beryl, hyacinth 
(?= sapphire), and all sorts of metals; the last is, however, not the 
case, Ceylon being rather poor in metallic ores. 

Under the name Bathana, a source of the onyx is mentioned 
by Ptolomey ; this appears to have been a well-known locality at 
Paithan on the Godaveri, which was alluded to as Plithana by the 
author of the Periplus. 

The sardonyx mines of Ptolomey are probably identical with 
the famous carnelian and agate mines of ERE or rather, as it 
should be called, Ratanpur. 

The loadstone rocks of India, whieh attracted so much notice 
by several early writers, were known to Ptolomey ; they may pos- 
sibly be identified with certain hill ranges in Southern India which 
mainly consist of magnetic iron.” Harly writers connected their 
presence with the fact that many of the vessels and boats engaged 
in the Indian coasting trade contained no iron in their construction, 


' See Economic Geology of India, p. 37. BGS iis Boos 


Batit—A Geologist’s Contribution to the History of India. 98 


and hence probably arose the well-known fable about the injury 
to shipping caused by the loadstone rocks. The surf boats, how- 
ever, have no iron in their construction, simply because bolts or 
nails would render them too rigid ; nor have the vessels of the 
Lacecadives and Maldives, because iron ores do not occur in coral 
islands. 

The identity of Argyre (where, according to Ptolomey, there 
were mines of silver), Chrysé chersonesus, Chryse chora, and Chal- 
kitts have recently been discussed by Colonel Yule.! 

The first he proves to be Arakan, where, however, there are 
no silver mines; and considering the geological structure of the 
country, it is almost certain there never were any. I have been 
recently informed by General Sir Arthur Phayre that Argyre is 
probably a transliteration of an ancient Burmese name for Arakan. 
It seems likely, therefore, that it was from putting a Greek interpre- 
tation to this name that the story of the silver mines owed its origin. 
According to Colonel Yule, the Arabs probably adopted their ideas 
from the Ptolomaic charts. With regard to the other localities, he 
says, “The golden Chersonese is specifically the protuberant delta 
of the Irawadi, Pegu, the Suvarna bhumi, or golden land of Ancient 
India, whilst the golden region behind is Burma, the oldest pro- 
vince of which, above Ava, is still formally styled in State docu- 
ments, Sona paranta, ‘‘Golden frontier.” Ptolomey’s Chalkitis, 
. also, or copper region, approximates curiously to the Tampa-dipa, 
or Copper Island of the Burmese State phraseology, “a region 
which embraces Ava and the ancient capital Pagan.” 

These identifications remove from the region of probability what 
has sometimes been urged, that Argyre and Chryse were countries 
which supplied India with large quantities of silver and gold. 
ARRIAN (Circa, A.D. 146.)—The first part of Arrian’s Indika 

was founded on the works of Megasthenes and Eratosthenes, and 
the second on an account of the voyage made by Nearchos the 
Kretan from the Indus to the Pasitigris. The parts of this com- 
pilation which bear upon our present subject have already been 
anticipated in the description of Megesthenes’ writings, and need 
not, therefore, be repeated. 

The authors whom I have consulted with reference to the 


1 Proceedings of the Royal Geographical Society, 1882, p. 654. 
12 


94 Scientific Proceedings, Royal Dublin Society. 


Roman trade with India are: Robertson,! Renaud,’ and Priaulx.* 
This trade, which succeeded that of the Greeks, came to an end in 
the sixth century. Besides what has already been independently 
quoted from the pages of Pliny and Ptolomey, there do not appear 
to be any records of much importance bearing upon the present 
subject. 

An account of India, written for Palladius towards the close of 
the fourth or begmning of the fifth century, makes special reference 
to the loadstone rocks, possibly quoting from Ptolomey. In the 
fifth century Hierocles speaks of the Brahmins as being clothed in 
garments made from a soft and hairy filament obtained from 
stones. This, it seems most probable, owed its origin to some 
mistaken notion as to the origin of cotton rather than to the use 
of woven asbestos, as has been suggested. 

Under the Emperor Justinian, in the sixth century, Cosmos 
(surnamed Indicopleustes), an Egyptian merchant, made several 
voyages to India, and recorded his experiences in a work called 
Christian Topography, in which some account of the export 
trade of India is given. He mentions how the Persians became 
rivals of the Romans at the Indian ports, and how the precious 
commodities were conveyed from thence up the Persian Gulf, and 
were distributed by means of the Huphrates and Tigris. Gradually 
the trade to Constantinople, the then seat of the Romans, was 
thus diverted. 

Eighty years after the death of Justinian, Mahomet published 
_ his new religion, and it was not long before the Arabians spread 
themselves as conquerors over the countries adjoining their own, 
thence spreading by sea and land over an ever-widening area. To 
a great extent they wrested the Oriental trade from the Persians ; 
they established a mart at Bussora, which speedily rose to an 
importance scarcely exceeded by that of Alexandria in the height 
of the Greek and Roman period. So little is known oi the details 
of this trade, that there is only barely sufficient evidence for the 


‘ Historical Disquisition concerning the Knowledge which the Ancients had of 
India. London: 1809. 

* Relations Politiques et Commerciales de l’Empire Roman avec 1’ Asie Orientile 
e o - pendant les cinque premiers siécles de l’ére Chrétienne. Jour. Asiatique, 6th ser., 
18638, tome 1. 

3“ Apollonius of Tyana.’’ 


Batt—A Geologist’s Contribution to the History of India. 95 


conclusion that, as’ regards the mineral productions, it did not 
differ materially from that which preceded it in the hands of 
other nationalities. 

The most important work giving an account of India at about 
this period is the famous voyage by a Mahomedan traveller, with 
annotations by another, called Abu Seid al Hassan of Giraf. 
Their account is confirmed by another Arabian called Massoudi, 
whose universal history bears the fantastic title, Meadows of Gold 
and Mines of Jewels. 

‘The effect of this absorption of the trade of the Red Sea was to 
deprive the Huropean nations of that highway of commerce, and 
the requirements of Europe had to be brought to Constantinople 
from India and China by long and tedious overland journeys, 
which became especially arduous during the Crusades. This state 
of things continued till the discovery by the Portuguese in the 
fifteenth century of the long sea passage round the Cape of Good 
Hope. 

From various sources, however, we are lien to pick up frag- 
ments of information referring to different centuries included in 
this interval. Thus a Sanskrit work called the Brhat Sanhita,’ 
which, it is believed, was written in the sixth century, contains a 
very detailed account of diamonds, their varieties, qualities, and 
attributes. Of especial interest is a list of eight localities where 
diamonds were found. Most of these I have succeeded in iden- 
tifying with sites where diamond mines are known to have been 
worked. With regard to some of the localities, however, it is 
more than doubtful whether they ever produced diamonds. 

The first Englishman who visited India appears to have been 
Sighelmas, Bishop of Shirburne, who was sent thither, in the year 
883, by King Alfred, to visit the famous Christian named St. 
Thomas. This Bishop, we are told, made his journey in comfort, 
and brought back with him “many splendid exotic gems and 
spices, such as that country plentifully yielded” *—a fact in itself 
of no great importance, save that it is a link in the chain. 


1 First translated in a.p. 1718 into French by M. Renaudot. 
. * Translated by Dr. Kern, Jour. Roy. Asiatic Society, vol. vii. N.S. 1875, p. 125. 
3 Keonomic Geology of India, p. 2. 
- 4 Recorded by William of Malmesburie in De Gestis regum Anglorum, Book ii. 
cap. iy. Vide Hakluyt’s English Voyages. 


96 Scientific Proceedings, Royal Dublin Society. 


Somewhere between the years 1067 and 1081 Marbodius 
wrote a poem entitled De Lapidibus Preciosis, in which he gave 
expression to the then prevailing ideas as to the sources and 
qualities of the diamond. . Far India is recognised as its native 
place, and the use of splinters of it for engraving upon other gems 
is alluded to. Its hardness is said to yield to steeping in goat’s 
blood—a fable already quoted from Pliny. How this idea origi- 
nated it is not easy to say; possibly it may be connected with the 
sacrificial offerings which preceded the search for diamonds, as ull 
be described on a future page. 

In the eleventh century, according to Dr. Burnell, wealth 
must have abounded in Southern India, because it was then that 
the numerous Sivoid temples were built; and in the thirteenth 
century the great Vishnu temples were erected. Regarding the 
famous inscription on the Tanjore temple, he has written as 
follows :— 

‘The full importance in Indian history of Vera Cola’s reign is 
only to be gathered from this inscription; but it contains other 
information also of great value. It proves, e.g., that in the 
eleventh century gold was the most common precious metal in 
India, and stupendous quantities of it are mentioned here. Silver, 
on the other hand, is little mentioned; and it appears that the 
present state of things, which is exactly the reverse, was only 
brought about by the Portuguese in the sixteenth century. 

“T submit that the great abundance of gold spoken of in the in- 
scription can have arisen only from mines, and that in the terrible 
convulsions caused by the irruption of Moslem invaders from the 
north and Europeans from the west, the position of these gold- 
fields was lost sight of.” 

It has been remarked upon this, that* “the full signi- 
ficance of this statement as affecting Southern India can be 
understood only when taken in connexion with the large areas 
which are known to have been worked by the natives. It seems 
to leave little room for doubting that the reefs and soils when first 
opened up were extremely rich, and that the soils as we find them 
now have been impoverished by repeated washings. 

“In the year 1293, Allahud-din, afterwards Emperor of Delhi, 


* Brough Smyth: Report of Geld Mines of South-East Wynaad, &c. 


Batt—A Geologists’s Contribution to the History of India. 97 


took the city of Deogarh, but the citadel still held out. Sub- 
sequently Allah raised the siege, on receiving a ransom, the 
amount of which may well appear incredible, 15,000 lbs. of pure 
gold, 175 lbs. of pearls, 50 Ibs. of diamonds, and 25,000 lbs. of 
silver, being enumerated among the items. So much appears 
certain, that Allahu’d-din levied an enormous sum upon Deogarh, 
and that consequently it must at that time have been a very great 
city and rich emporium.”? 

It has been suggested that this waaltt must have bean acquired 
by working the ancient mines of Southern India. 

Mauomep BEN Mansur (thirteenth century).—The remarkable 
Persian work on Precious Stones by this author was translated 
first into German by Joseph von Hammer.’ The following facts 
are from an English version’ :— 

Diamond. —Seven kinds are recognized, namely, (1) white 
transparent ; (2) the pharonic; (3) the olive-coloured, the white of 
which inclines to yellowish; (4) the red; (5) the green; (6) the 
black ; (7) the fire-coloured. 

In spite of this elaborate classification, Mahomed’s knowledge 
of the habitat is very vague. He says :—“ In the eastern parts of 
India is a deep ravine, inhabited by serpents, where diamonds are _ 
produced. Some people suppose that it-is found in the yakut 
mines.” 

Here there is an obvious allusion to the diamond myth—to be 
described hereafter. 

Corundum (Senbade), he says, quite correctly, is next in 
hardness to the diamond, and is of a reddish or bluish colour. 
The mines were situated in India, Zanzibar, Siwas, Kerman, 
Nubia, and Ethiopia. The best kinds were from Siwas and Nubia. 

Yakut. — Under this title are included six classes: (1) red 
(i.e. ruby); (2) yellow (2.e. Oriental topaz); (3) black (¢.e. pleo- 
naste); (4) white (7.e. white sapphire); (5) green (¢.e. Oriental 
emerald); (6) blue, or smoke-colour (?.e. sapphire). Of theso 
classes sub-divisions into varieties are given. It is certainly a 
most remarkable fact that at so early a period the essential 
identity of these precious stones—a fact only comparatively 


1 4 Hand-book for Madras. John Murray, 1859, p. 94. 
2 Mines de l’Orient, vol. vi. 
3 Asiatic Journal, vol. ix. 1820, p. 345, 


98 Scientific Proceedings, Royal Dublin Society. 


recently ascertained by chemical examination — should have been 
known to the Persians. The hardness and other characters are 
correctly stated also by Mahomed. The locality of the principal 
mines is stated to be the island of Saharan, which is sixty-two 
farsanges in diameter, and lies forty farsanges behind the island of 
Ceylon. The yakuts are found there in a high mountain. This 
jumble is not easy to explain, the true locality being Ceylon itself,. 
which is noted for its high mountains, culminating in Adam’s Peak. 

Another locality is also mentioned, Tara, near Cairo, where 
mines were discovered a.p. 1270. 

A stone, called by Mahomed the chamahen, should come 
here, if, as is stated, it is next to the diamond in hardness; but 
this is inconsistent with another assertion that, when rubbed on a 
hard stone, it colours it red. When broken, it divides into 
branches. The most beautiful is blackish-red; it is found in the 
district of Karak. But for the first statement I should be inclined 
to identify this as jasper. 

Spinel (Laal).—Of this there are four classes, namely, the red, 
yellow, violet, and green. Of the red there are eight varieties. 
Mahomed only mentions one mine, that in Badakshan, the capital 
of which, Balkh, gave origin to the term “ Balas.” His account, 
which is as follows, was unfortunately not available to me when 
giving a précis of information regarding the locality’ :—“ At the 
time of the caliphate of the Abbasides, 2 mountain at Chatlan 
was rent open by an earthquake, where there was found the /aal 
of Badakshan, bedded in:a white stone. It is very hard to polish, 
and it was a long time before it could be smoothed, till it was at 
length accomplished by means of the gold marcasite called 
ebrendshe. Smaller stones are found in the bed round a large one, 
like the seeds of a pomegranate. The miners call this bed of the 
Spinel maa/l. There were found in the mines first red, then 
yellow /aal, and it belongs to the kinds of the yakut.” The 
discovery of these mines by a landslip finds a parallel in a recent 
discovery of sapphires in the Himalayas.* The white stone which 
formed the matrix is probably limestone. Wood, in 18387, stated 
that the matrix was a red sandstone or a limestone impregnated 
with magnesia, but he did not personally visit the mine. 


1 Economic Geology, p. 430: 
* Records of the General Suryey of India, vol. xv., 1882, p. 138. 


Batt—A Geologist’s Contribution to the History of India. 99 


Turquoise (Firuse)—Obtained at Nishabar, Ghasna (? Ghuznee), 
Irak, Kerman, Chouresm, the first being the most valued. There. 
is, therefore, no Indian locality : such seems to be still the case. 

Tale (Sitarei semin = star of the earth)—Two kinds—one found 
in the air (? superficially), and the other in mines. Mahomed says 
—“ artificial pearls are made from it, and it does not burn or calcine 
with fire. If you dissolve it and rub the limbs with it, it makes 
them fire proof. Talc can neither be pounded in mortars nor broken 
to pieces with hammers. The way to dissolve it is to boil it with 
beans ; to wrap it then in a piece of linen. If dissolved tale is 
mixed with a little resin and saffron, and used as ink, it makes a 
gold ink, and, without saffron, silver ink.” 

Rock Crystal (Bellor).—Of this two kinds are mentioned, one 
being clear, and the other dark-yellowish. The added statement 
that they can be melted like glass, and then coloured so as to 
imitate the yakut, laal, or emerald, is unintelligible, since rock 
crystal by itself is a most infusible substance. Perhaps what is — 
meant is, that siliceous sand was used in the manufacture of the 
glass or paste of which false stones were made. 

Mahomed says that at Ghasna, there were four crystal vessels, 
each of which could contain two skins of water. He mentions 
that crystals of other minerals and wood (probably crystals of 
tourmaline) often occurred enclosed in the bellor. Some fanciers, 
we are told, prefer the Arabian to the Indian variety. 

Amethyst (Dschemst)—Four kinds: (1) deep rose-colour and 
sky-blue; (2) pale rose-colour and deep azure; (8) pale rose- 
colour and sky-blue. It was much esteemed by the Arabs. 
Mahomed does not refer to its occurrence in India, but states that 
it was obtained near the village of Safwa, three days’ journey from 
Medina. Wine drunk out of a goblet made of amethyst does not 
intoxicate, upon which Mahomed’s translator remarks :—“ This 
opinion was also current in Hurope, and the name dschem or 
dschemsshid is connected with it. The Greek word ayeOvoroe also 
means “unintoxicated,” but it is originally derived from dschemest, 
as the jasper from jaschep ; hyacinth from yakut ; emerald from 
Semerrud ; pearls (Margarita) from merwarid; turquoise from 
Jiruse; lapis-lazuli from Jdadschwerd; sardonyx from sard; tale 
from talk; chalk from kals.” 

Emerald (Semerrud).—Seven varieties or different shades are 


100 Scientific Proceedings, Royal Dublin Society. 


recognised. ‘The mine was situated on the border of Negroland, 
in Hgyptian territory. ‘The matrix of the gem was tale and red 
earth. It seems probable that this was the source of the emeralds 
which went to India, and also supplied the Greeks and Romans. 
A soap-green emerald was also found at Hedshas, in Arabia. 

Owing to the fact that jade was not recognised as a distinct 
mineral until introduced into Europe from the New World, the 
older writers sometimes, on account of its hardness and transpa- 
rency, spoke of it as emerald, while others applied to it the term 
jasper. ‘There can be no doubt that jade is meant by the follow- 
ing, not jasper, as his translator has it :— 

Jaschep, or Nussz.— Five kinds: (1) white and light; (2) 
whitish yellow; (3) black-green; (4) transparent black; (5) dust- 
colour. . 

Mahomed adds that in China they make false jaschep, which 
is distinguished by’ its smoky smell, and that there are two 
mines in China called respectively Ak-Kash which produces light, 
and Kut-Kash which produces dark jaschep. It is found on the © 
frontiers of Kashgar, Kerman, and Arabia. 

Kash is the name for jade current in Kastern Turkistan, and 
sw or sw is the name by which it is known to the Chinese, who 
~ esteem it more highly than do the people of any other nation.' 

Chrysolite ? (Sheberdshed).—This is said by Mahomed to be 
obtained in the same mine as the emerald, of which it is a variety 
according to some authorities. If so, it cannot be what is now 
known as chrysolite, which is the transparent variety of olivine. 

Mahomed mentions a number of other minerals, among them 
several ores. Of the magnet he says there are four kinds, namely, 
the iron, gold, silver, and tin, which attract these metals respec- 
tively; possibly by this it is meant to be conveyed that ores ascer- 
tained to contain these metals exhibited magnetic properties. 

The following statements, regarding the knowledge possessed 
by the Persians of the relative specific gravities of some precious 
stones, are of interest :— 

‘‘Abu Rihan is said to have found by experiment that a 
muskal (=13 drachms) of blue yakut (sapphire) is equal to five 
dank and a tissu of red yakut (ruby), or to five dank and two and 


1 Economic Geology, p. 516, et. seg. ; and also p. 109 of this Paper. 


Batt—A Ceologist’s Contribution to the History of India. 101 


a-half tissu of /aal (spinel), and that four dank, minus a tissu of 
coral, are equal in size to four dank, minus two tissu of onyx and 
crystal. The mode of discovering the size and weight is the 
following :—A. vessel is filled with water, and the stones thrown 
singly into the water; the quantity of water which is expelled 
from the vessel by means of each stone is equal to the room it 
occupies.” 

Marco Poto.—A notable authority on the mineral production 
of India during this same thirteenth century is the famous Venetian 
traveller, Marco Polo. In reference to the diamond, he states that it 
was only obtained in what he designates asthe kingdom of Mutfili— 
a name which has been identified by Colonel Yule with Motupalle, 
a still existing port in the Guntur District of Madras. The proper 
name of the kingdom was Telingana, which therefore included the 
so-called Golconda mines of the Kistna Valley ; but Marco Polo ex- 
tended to it that of the town or post which he visited. It is note- 
worthy, as testimony of an early trade, that Marco Polo states 
that “those diamonds brought to Europe are, as it were, the re- 
fuse of the finer stones, which go to the Great Kaan and the other 
kings and princes of India.’”’ He describes three methods as being © 
followed in the search for diamonds :— 

First : Aiter the rains the beds of torrents from the moun- 
tains were searched ; these localities were infested with venomous 
snakes. 

Second: Pieces of meat were thrown down fiom the tops of 
mountains into inaccessible valleys; these pieces of meat were 
pounced upon and carried up to the tops of mountains by white 
eagles, and, when recovered, diamonds were found sticking to 
them. ‘This story, made familiar to all by the travels of Sindbad 
the Sailor, is one of great antiquity. The earliest mention of it, 
according to Colonel Yule, is by St. Epiphanius, Bishop of 
Salamis, in Cyprus, who, in the fourth century, wrote a treatise 
on the twelve jewels in the breastplate of the High Priest. The 
tale, as told by him, however, refers to the jacinth, a to the 
diamond. 

A list of the anthors who have alluded to this tradition will be 
found in Colonel Yule’s edition of Marco Polo.’ Its origin, as 


1 Vol. ii. p. 298. 


102 Scientific Proceedings, Royal Dublin Society. 


first suggested by me,’ I shall discuss in connexion with the 
account given by Nicolo Conti. : 

Third: This method, which may be described as a corollary of 
the second, consisted in searching the birds’ droppings and intes- 
tines for diamonds which they had swallowed with the meat. 

Marco Polo, in various parts of his book, refers to other 
precious stones, especially to the Balas rubies and “azure” or 
lapis-lazuli of Badakshan. The value of the former was kept up 
by a limit being imposed by the king on the out-turn. The 
latter, he says, occurred in a vein like silver, and was the finest in 
the world. 

In reference to gold and silver? there are several important 
facts recorded; among others, the enormous extent of the accumu- 
lation of gold in the treasuries of the princes of Southern India, 
upon which Colonel Yule remarks, after speaking of the spoil 
earried off by Allahud-din, that “some years later, Mahomed 
Tuglak loads two hundred elephants and several thousand bullocks 
with the precious spoil of a single temple.’ And a further state- 
_ ment, given on the authority of Wassaf, is, that “ Kales Dewar, 
Raja of Malabar, about the year 13809, had accumulated ea) 
crores of gold, 7.e. 12,000 millions of dinars.” * 

Marco Polo distinctly mentions copper, gold, and silver as 
being imports into Malabar and Cambay from Hastern countries 
in his time. 

Fertsuta.—Our next authority is the Indian historian, Ferishta, 
who wrote in 1425. What he says on the subject is chiefly of im- 
portance as confirming other evidence of the great wealth possessed 
by the princes of Southern India in the form of stores of precious 
stones and bullion. It has already been partly quoted on page 96. 
He refers to now long-deserted diamond mines in the Central Pro- 
vinees of India,‘ which I have been able to identify as having been 
situated at Wairagarh, in the Central Provinces. 

Nicoto Conrat.—The last writer of what may be called the fabu- 
lous period, which closed with the fifteenth century—at least in so 
far as regards the diamond fable—was the Venetian, Nicolo Contai, 


1 Jour. As. Society, Bengal, vol. x. pt. ii. p. 31. 

2 G., vol. i. pp. 276, 284; S., ibid. pp. 325 and 327. 

3 Marco Polo, vol. ii. p. 284, note 6. 

4 History. Ed. by J. Briggs. London; 1819, vol. ii. p. 261. 


Batt—A. Geologist’s Contribution to the History of India. 103 


an account of whose voyage is given by Baptista Ramusio' in his 
book of Voyages and Travels, on the authority of Messer Pogio, 
Fiorentino. The locality where the diamonds were found was at 
Abnigaro, fifteen days’ journey northwards from Bisnagar.’ As 
to its identity I am not yet quite satisfied. We are told that the 
mountain which produced the diamonds was inaccessible, being 
infested with serpents, but was commanded by another mountain 
‘somewhat higher. ‘Here, at a certain period of the year, men 
bring oxen, which they drive to the top, and having cut them into 
pieces, cast the warm and bleeding fragments upon the summit by 
means of machines which they construct for the purpose. The 
diamonds stick to these pieces of flesh. Then come vultures and 
eagles flying to the spot, which seizing the meat for their food, fly 
away to places where they may be safe from the serpents. To 
these places the men afterwards come and collect the diamonds 
which have fallen from the flesh.” 

He then describes a different process, which is simply that of 
washing for diamonds in the beds of rivers. For as far back as 
we have any certain knowledge of them, the diamond miners have 
all belonged to one or other of the non-Aryan or aboriginal tribes, 
who regard the mines as being the special property of the blood- 
thirsty goddess, Lakshmi, whose cruel nature requires much 
propitiation. 

To this day sacrificial offerings are made to her on the opening 
up of mines, of whatever sort, and occasionally the meat is placed 
on an altar-like scaffold; and in India, as a matter of course, 
vultures and kites, with other raptorial birds, would carry away 
and devour whatever portions of meat they could seize upon. 

Out of this custom it seems to me most probable that the 
tradition grew which has now attained to such a respectable 
antiquity. Lookers-on, unacquainted with the semi-savage rites, 
regard them as essential parts of the search for diamonds. 

Usrromannvus.—In the year 1503, Lewes Uertomannus, who is 
described as a Roman gentleman, travelled in Western and Southern 
India. The account of his travels contains some interesting. parti- 


' Delle Navigationi et Viaggi. Venice: 1613. 

2 These two names are so written in Ramusio’s volume, but in a translation of the 
passage, published by the Hakluyt Society, they are given as Albenigaras antl 
Bizengulia. 


104 - Scventific Proceedings, Royal Dublin Society. 


culars bearing on our present subject.1 Of Cambaia he says (p. 381): 
“Tn this region is also a mountaine where the onyx stone, com- 
monly called corneola, is founde, and not far from thence also 
another mountaine where the caleedony and diamant are founde.” 
If by diamant the diamond is meant in this passage, the fact is 
noteworthy, as the Ponassa of Ptolomey is probably identical 
_with the modern Ponassa in this region. At the same time a 
doubt must be expressed as to true diamonds having been ever — 
found there. Further on our author says (p. 383): “Sixe 
miles from the city of Decan (? Bisnagar) is a mountaine where 
diamonds are digged. It is compassed with a wall and kept 
with a garrison.” 

Uertomannus mentions that two European dealers in precious 
stones, named respectively John Maria and Peter Antonie, resided 
at Calicut with the king’s licence. They had acquired a fair 
diamond of 32 carats, worth 35,000 crowns, a pearl of 24 carats, 
and 2000 rubies, some of 1 carat, and some of 1} carats. On their 
attempting to depart secretly with their treasures to Cannanore, 
they were murdered by order of the king. 

Under the heading, ‘‘Of the Diamondes of the Old Myne,” 
our author says (p. 424):—“ These diamondes are found in the 
first India, in a kingdom of the Morres, named Decan, from 
whence they are brought to other regions. There are also found 
other diamonds which are not so good, but somewhat whyte, and 
are called diamondes of the new myne, which is in the kingdom 
of Narsinga (Lower Kistna). They of the old mine are not 
pollyshed in India, but in other places. There are made lykewise 
in India false diamondes of rubies, topazes, and white sapphires, 
which appear to be fine, and are also found in the island of Zeilan 
(Ceylon). These stones differ in none other save that they have 
lost their natural colour.” In another place he gives information 
as to the local prices of other precious stones, as rubies, spinel, 
sapphires, topaz, &c. 

Next follow a group of authors, the accounts of whose travels 
are to be found in Baptista Ramusio’s above-mentioned work. 
The first of them is Andrea Corsali, Fiorentino, whose letter, 


‘The History of Travel, &c., done into English from the original Latin. By 
R. Eden and R. Willes. Lond. :: 1577. 


Batt—A Geologist’s Contribution to the History of India. 105 


addressed to Signor Guliano de Medici, Duca di Fiorenza, is dated 
Cochin, 6th January, 1515; it contains only a few unimportant 
facts bearing upon this subject. 

Another of these authors is Ludovico Barthema, whose infor- 
mation is almost identical with that already quoted from Lewes 
Uertomannus. The precise date of Barthema’s work I have been 
unable to ascertain. 

From the book of Odarodo Barbosa, which refers apparently 
to a period about the year 1519, and to a voyage to India made 
by way of the Cape of Good Hope, we learn that at Bisnagar, 
2.e. Vijayanagar, jewels brought from Pegu and Ceylon were on 
sale in great abundance, as also were diamonds from Narsinga. 
This author gives also a full account of the values, &e., of a 
number of precious stones, namely, rubies, spinel, diamond, 
sapphire, topaz, turquoise, hyacinth, and emerald, and mentions 
the localities where they were obtained, but these details are too 
voluminous for reproduction here. 

Garcras AB Horro.—Our next authority is Garcias ab Horto, | 
a physician resident at Goa, who, in 1565, produced a work in 
Portuguese, containing a considerable amount of interesting and— 
much of it, though not all—obviously accurate information on our 
present subject.’ 

He tells us that there are two or three loellies near Bisna- 
gar (Vijayanagar) where diamonds were obtained, the industry 
being a considerable source of revenue to the king, as all stones 
above 380 mangelis (=150 grs.?) became his property. Another 
mine also in the Decan produced excellent diamonds. It was 
situated in the lands of a native prince, near the territory of 
Imadixa (i.e. of Ahmed Shah?). This last was probably identical 
with the mine at Wairagarh, in the Central Provinces. 

Garcias treats with scorn the old fable of the valley inhabited 
by serpents, and moreover points out that a Jesuit father, Francois 
de Tamara, who had repeated it, was therefore not worthy of 
credence, when he stated that diamonds were to be found in 
Brazil. The statement is of importance when it is remembered 
that the first diamond mines in Brazil were not opened up till 
1728, or more than 160 years later. It may be added that the 
version of the fable just alluded to is that one where the serpents 


1 De Arom. et Simp. Historia, a Latin version by Clusius of Antwerp, 1567. 


106 _ Scientific Proceedings, Royal Dublin Society. 


guard the jewels, and while they are engaged eating the meat 
thrown to them, the diamond-seekers are enabled to pick up the 
stones. Garcias speaks of several large diamonds which were 
known-to exist in his time; two weighed 140 and 120 mangelis 
respectively (¢. ce. 700 and 600 grs.). Far exceeding these in size 
was one which he had heard of from a native who had seen it; it 
was said to be equal in size to a fowl’s egg; it weighed 250 man- 
gelis, or 1250 grs. This was, according to Tavernier, who wrote 
a century later, the form of the Great Mogul diamond when 
originally found. So that it seems quite possible that this casual 
notice by Garcias is the earliest mention of that famous stone. 

Even in the time of Garcias it would seem that the tailings 
from earlier washings were sometimes rewashed with good results. 
He states that Lispor, in the Decan, was a principal mart for the 
sale. (Can this have been Vizapur or Bijapur ?) 

The geographical limits of Balaghat—a name used not only 
by Garcias, but also by some other writers—it would, probably, be 
impossible to closely define now. The name is still conserved as 
that of a particular district, but in early times it seems to have 
been applied to all the region in Southern India above the Ghats, 
which was sometimes also called the Carnata, a name now, how- 
ever, restricted to a district below the Ghats. 

With reference to other precious stones, Garcias states that a 
false smaragdas (emerald) was made of glass in Balaghat and 
Bisnagar. He distinguishes four varieties of ruby, as the true, 
carbuncle, balas, and spinel. Of sapphires he says two kinds 
were found in Calicut, Cannanore, and several places in Bisnagar. 
We have no knowledge of true sapphires ever having been obtained 
in these districts. Both hyacinth and garnet were found in Calicut — 
and Cannanore, the latter being distributed throughout the whole of 
Cambay and Balaghat. Beryl was found in Cambay, Martaban, 
and Pegu, also in Ceylon: glasses and vases were made from it. 

Garcias states that the Murrhine Cup was made of jasper; 
more correctly, perhaps, it was made of carnelian, as suggested on 
a previous page. 

Casar FrepERicK.—About the year 1567, a aero named 
Cesar Frederick' visited Western and Southern India. In a trans- 
lation from his original account we find the following passage :— 


1 A translation of tis account of his travels is given in Heeet Noreen vol. il. 
1599, p. 218. 


Bart—A Geologist’s Contribution to the History of India. 107 


“The rubies, saphyres, and the spinels be gotten in the kingdom of 
Pegu. The diamants come from divers places, and I know but three 
sorts of them. That sort of diamants that is called chiappe cometh 
from Bezeneger. Those that be naturally pointed come from the 
land of Delly and Iawa (by which we must understand Borneo), but 
the diamants of Iawa are more waightie then the other. I could 
never understand from whence they that are called balassi come.” 
The signification of chiappe is uncertain. The naturally-pointed 
_ stones probably came from Chutia Nagpur, or Kokrah, as it was 
then called, since Tavernier describes the stones from that region — 
as being of this character, and it is believed that they were taken 
to Delhi. The term “ balas” was applied to the spinel rubies 
from Badakshan. Possibly, it may have been used st0E those 
diamonds which had a roseate tinge. 

On another page Frederick says :—“ Also, five oe journey 
from Bezeneger, is the place where they get diamants. I was not 
there, but it was told me that it is a great place, compassed with a — 
wall, and that they sell the earth within the wall for so much a 
squadron, and the limits are set how deepe or how low they shall 
digge. Those diamants that are of a certain size, and bigger then 
that size, are all kept for the king. It is.many years agone since 
they got any there, for the troubles that have been in that 
kingdom.” 

Fircn anp Newsrrry.—The famous traveller, Ralph Fitch, 
and his companion, Newberry, have left on record an account of 

_ their journeys in India, which refers to the years about 1683. 
‘In reference to precious stones, the following are the most impor- 
tant passages:—Bellergan, the modern Belgaum, was said to be 
“a great market of CLARE, rubies, sapphires, and many other 
soft (i.e. precious) stones.” We are told that a jeweller named 
William Leades, who was one of their party, remained behind 
them in the service of the King of Cambay. 

The next passage explains the use of the name Iawa, or Java, 
by Caxsar Frederick, and others :—“ Laban (i.e. Borneo, the name 
being retained in Labuan) is an island among the Iawas, from 
whence come the diamants of the new water, and they find them 

‘in the rivers, for the king will not suffer them to digge the rock.” . 


1 Hakluyt’s English Voyages, vol. ii. 1599, p. 208. 
SCIEN. PROC. R.D.S.—VOL. IV. PT. II. K 


108 Scientific Proceedings, Royal Dublin Society. 


Speaking of Patanaw (Patna) on the Ganges, below Banaras, it 
is said :—“ Here at Patanaw they find gold in this manner. They ~ 
digge deepe pits in the earth, and wash the earth in great bolles, 
and therein they find the gold, and they make the pits round 
about with brick, that the earth fall not in.” I cannot but think 
that there is a mistake here, due to an account of gold-washing in 
the country to the south having been mixed up with a description 
of the method of sinking ordinary irrigation-wells in the neigh- 

bourhood of Patna. It is not likely that gold was ever found in 
sufficient quantity in the Gangetic STL an aaa. near Patna, to repay 
the cost of searching for it. — 

Axsput Fazi.—Here we may turn aside again from Huropean 
authorities to an Oriental writer, who, being a Mahomedan like the 
already quoted Ferishta, presents us with much more useful and. 
matter-of-fact statements than are to be found in any, works by 
Hindus. Abdul Fazl, the author of the Ain-i-Akbari, written 
in 1590, refers to the occurrence of and working for several mine- 
rals, especially diamonds, gold, and iron. The diamond mines at 
Beiragarh, in Gondwana, which he mentions as having been taken 
possession of by the ruler of Kullem, or Chanda, were probably 
the same as those already mentioned by Ferishta. In any case, it. 
is certain that Beiragarh may be identified with the modern 
Wairagarh in the Central oe where traces of the mines are 
still to be seen. 

Gold was obtained, he “om in seria streams in Kashmir by 
pegging down, under water, the hairy skins of animals, which 
served to arrest the auriferous dust in its descent with the current. 
Long ago it was suggested that such skins were the origin of the 
idea of the skins of the gold-digging ants, mentioned by Nearchos 

_and others, but the explanation given on a previous page is the 
more probable one. He alludes to the “steel” mines at Nirmal, 
which can be identified with a locality in Hyderabad, where a © 
high quality of steel was prepared, most of which found its way to 
Persia, for manufacture into the Damascus swords, to which refe- 
rence has already been made. 

The enormous salt deposits of the Punjab are noticed by 
Abdul Fazl; and here may be quoted | a passage from Strabo," 
which should have appeared on a previous page :— 

“Tt is said that in the territory of Sopeithes there is a moun- 


1 B. xy., chap. 1. 8. 30. 


Bart—A Geologist’s Contribution to the History of India. 109 


tain composed of fossil salt sufficient for the whole of India. 
Valuable mines also both of gold and silver are situated, it is said, 
not far off, among other mountains, according to the testimony of 
Gorgus, the miner of Alexandria.” Since this salt crops out at 
the surface, and in Kohat especially, can be easily quarried, it is 
only natural that it should have attracted attention in the very 
earliest times. 

- Gorz.—Recently I came upon a work, dated 1602, and entitled 
Travels of Benedict Goez from Lahore, in the Mogol’s Empire, 
_to China, in 1602,' which contains perhaps the earliest account, 
_ by a Huropean author, of the production of jade in Kashgar. He 
says:—“ The commodity best for carrying from Hirakan (i.e. 
Yarkand) to Katay (China) is a certain shining marble, which, for 
want of a fitter name, Europeans call jasper. ‘The King of Katay 
buys it at a great price, and what he leaves the merchants sell to 
others at exceeding great rates. Of it they make vessels, orna- 
ments for garments and girdles, with other toys, whereon they 
engrave leaves, flowers, and other figures. The Chinese call it 
tushe.* There are two: kinds—one more precious, like thick — 
flints, which are found in the river Kotan, not far from the city 
royal ;* the other meaner sort is digged out of quarries and sawed. 
into slabs about two ells in breadth. The hill where they are 
dug, called Kosanghi Kasho, or the stony mountain, is twenty 
stages from the same mountain. . This marble is so hard that 
they must soften it with fire to get it out of the quarry. The 
king farms it every year to some merchant who carries provisions 
for the workmen for that space of time.” 

Goez mentions (p. 647) that besides this jasper (.e. jade), 
“‘ diamonds of the rock,”’* and azure (¢. e. lapis-lazuli) were carried 
as presents by ambassadors from the West to the Emperor - 
China. 

As stated in my Economic Geology (p. 517), the mines of 


1 New General Collection of Voysees and Travels. London: T. Astley. 1747. 
Yol. iy. p. 646. 

2 In the original, Twsee—a mistake, no.doubt, for ‘Yu she.” 

3 By the Jesuits’ map the river of Kotan runs about ninety miles east of Yarkand. 

4 T am not quite clear as to the precise significance of this phrase, “‘ diamonds of 
the rock,’ unless, perhaps, it is equivalent to ‘‘diamonds of the old mine,’’ an 
expression apparently used for stones having crystalline forms, called naifes in India, 
as contrasted with ‘‘ diamonds of the new mine,” which were rounded pebbles. 


110 Scientific Proceedings, Royal Dublin: Society. 


Kotan are mentioned by Chinese authors who wrote 2000 years 
ago; and the system of dredging the rivers of that region for jade 
is known to have been in practice for many centuries. Other 
mines are situated at Karakash, in the Kuenlun range. These 
have been visited and described by several Europeans of late 
years. ! 

Recently a rather general acceptance has been given to the 
view advocated at great length by Fischer, that the discovery of 
jade implements in Swiss lake dwellings is testimony of a pre- 
historic immigration of Asiatic tribes into Hurope, as there is said. 
to be now no known source of the material in Europe. This view 
has been, I understand, lately contested by Dr. Meyer, of Dresden, 
but I have not yet seen his work on the subject. 

In the year 1609, De Boot published his famous work on 
precious stones. This, however, being merely a compilation as 
regards the information given about India, there is nothing in it 
which is not contained. in the already quoted authors. It may 
also be added here, that the edition of De Boot’s work, published 
by De Laet in 1847, only adds to his account facts derived from _ 
Methold. . 

Janancrr.—In the Tusuk-i-Jahangiri (1616),' an account is 
given of diamond mines in the Chutia Nagpur, province of Bengal, 
which I have shown to be indentical with the Soumelpour, visited — 
and described by Tavernier, as will be mentioned on a future page. 
There is no local tradition as to the precise site of these mines, 
which, therefore, remain to be rediscovered; but the search was 
certainly conducted in the bed of the Koel river. 

Mrrnoip.—Our next authority is an English traveller named 
William Methold, whose account? of a visit to the diamond mines, 
made by himself and others, is entitled Of the south-eastern parts, 
viz., Golchond, and other adjacent Kingdoms within the Bay of © 
Bengala. The visit appears to have been made between the years 
1622 and 1626, the latter being the date of the publication.. 

The mines were situated 108 English miles from Masulipatam ; 
they had only recently been discovered by the chance finding of a 
valuable stone by a goat-herd: when seen by Methold they gave 


1 Translated by Blochmann, Jour. As, Soc. Bengal: vol. xl. p. 113. 
2 Purchas’s Pilgrims, vol. vy. p. 1002. London; 1626. 


Bart—A Geologist’s Contribution to the History of India. 111 


occupation, according to native report, to 30,000 persons, a large 
proportion of whom were engaged in baling out the mines by 
hand—a tedious operation still practised in some parts of India. 
The mines were farmed out by the king for a sum of 300,000 
pagodas, but he reserved'to himself all stones of above 10 carats 
weight. In 1622 the mines were temporarily closed, owing to an 
ambassador from the Great Mogul having demanded a tribute of 
38 Ibs. weight of the finest diamonds. The locality was situated on 
the Kistna: river, and was probably identical with the Gani or 
Coulour of Tavernier, the exact position of which has only re- 
cently been satisfactorily fixed as being identical with the modern 
Kollur. : 

Lorp.—In the year 1630, a clergyman named Henry Lord, who 
was attached tothe English establishment in Western India, published 
a curious pamphlet, entitled The Discovery of the Banian (7.e. Brah- 
min) religion. In it he gives an account of the Brahmins’ ideas as 
to the first discovery of diamonds. It is attributed by them to the 
first progenitor of the Sudras or lowest caste of Hindus. . Now the 
_ diamond miners throughout India, with rare exceptions, so far as I 
have been able to ascertain, still belong, and have always belonged, 
either to the Sudras or the aboriginal tribes, with whom they are much 
mixed up. This fact I hold to be of much importance in connexion 
with the explanation which I have offered of the origin of the 
diamond mining fable in connexion with the accounts of it given 
by Marco Polo and Nicolo Conte. 

TavERNIER (1665-1669).—In the accounts of his several 
journeys in India, Tavernier has given us a considerable amount 
of information, the value of which is, however, affected by the 
fact that these accounts contain a number of internal inconsist- 
encies which it is impossible to reconcile with one another. 

Diamonds.—Upon this subject the old jeweller naturally dis- 
courses at length: as, however, I have already quoted his facts in 
a former Paper,' I shall only here mention that the diamond mines 
at Raoleonda, Gani or Colour, and Soumelpour have been identified 
by me? with the modern localities, Ramulkota, Kollur, and a spot 
on the Koel river in the district of Palamowin Bengal. Another 


1 These Proceedings, for 1880. 
2 Economic Geology of India. 


112 Scientific Proceedings, Roy aaal Dublin Societe Y. 


locality which he mentions, namely, Gandicota, has. also been 
identified. 

If Tavernier’s statements regarding the discovery and cutting 
of the Great Mogul diamond are to be relied upon, then that stone - 
must have been distinct from the koh-i-nur. When writing of 
their probable identity, I overlooked the independent evidence 
which exists as to the koh-i-nur having been in the possession of 
the Mogul emperors long previous to the time when, aceoudlins to 
Tavernier, they acquired the Great Mogul. 

Gold.—In reference to this metal Tavernier says :-—“ Towards 
the Thibet, which is the ancient Caucasus, in the territories of a 
Raja beyond the Kingdom of Cashemir, there are three mountains 
close by one another, one of which produces excellent gold... .” 

“There is gold also comes from the kingdom of’ Tipra (Tip- 
perah on the borders of Assam); but it is coarse, almost as bad as 
that of China.” 

If gold washing or mining was carried on in any part of Penin- 
sular India at the time of his visits, it is certainly remarkable that, 
he should have been unaware of it, especially as he had heard of 
its being worked for in Thibet and Tipperah. Still I cannot but 
suppose that there were washings in some remote regions of which 
he knew nothing. 

Silver and Tin.— As for silver mines (he writes), there are none 
in all Asia, but only in Japan; but some years since at Delegora, 
Sangora, Bordelon, and Bata (localities in the Malayan countries), 
have been discovered air mines of tin, to the great damage 
of the English, there being now enough: in Asia, of their own 
besides (sc in English translation). 

The statement about silver is inconsistent with another made 
subsequently, that in Assam there were mines of both gold and 
silver. 

Rubies, Sapphires, &c.— What Tavernier says on the subject of 
these stones shows that he was unaware of the existence of any 
source for them in Peninsular India. He says that they occur in 
only two places in all the east, and then forthwith mentions three. 
“The first is a mountain, twelve days’ journey, or thereabouts, 
from Siren (¢.e. Siriam), toward the north-east, the name whereof 
is Capelan. In this mine are found great quantities of rubies 
and espinels, or mothers of rubies, yellow topazes, blue and white 


~ Batr—A Geologist’s Contribution to the History of India. 118 


sapphires, Bells, amethysts, and other stones of different 
colours. 25 

“The natives of the country call all coloured stones rubies, . 
and distinguish them only by the colour: sapphires they call blue 
rubies ; ariethints violet rubies ; topazes, yellow rubies; and so of 
other stones.” | 

The ruby mines are described in the Hconomic Geology of 
India, p. 427. They are situated about seventy miles north-east 
of Mandalay, the capital of Ava. 

“The other place where rubies are found is a river in the 
Island of Ceylon. . . . The people make it their business to search 
among the sands for melohas sapphires, and topazes. All the stones 
that are found in this river are generally fairer and clearer than 
those of Pegu.”’ 

“‘Some ‘rubies, but more Ballei’s rubies, and an abuntlanes of 
bastard rubies, sapphires, and topazes, are found in the mountains 
that run along from Pegu to the kingdom of Camboya.” 

Whether by Camboya Tavernier meant Cambodia, beyond 
Siam, is uncertain; but he can scarcely have meant Cambay. 
He says that it is an error to suppose that emeralds are found in 
the Hast. Those exported from the Philippines to Europe were 
first brought thither by Spaniards from Peru. 
_ In the above-quoted paragraph on gold in the region beyond 
Cashemir, the other two mountains he mentions produced “ granats”’ 
(i.e. garnets), and “azure” (é.e. lapis-lazuli), respectively. This 
reference is, doubtless, to well-known mines of the spinel or Balas 
ruby, and lapis-lazuli, which are situated in Badakshan.' 

In 1678, a work was published on Asia by John Ogilby, 
which, as giving an epitome of the knowledge possessed in Eng- 
land of the mineral resources of India at that time, is not without 
interest. But ‘some of the statements are not founded on fact. 
Thus, he says (p. 105) : “The Ganges is supposed to abound with 
gold and pearls, and from its bottom are fetched all manner of 
precious stones, on some of which are represented the shapes of 
beasts, plants, and other things.” And again: “The Kingdoms of 
Golconda and Decan afford the inhabitants excellent diamonds. 
India also produces topazes, berils, rubies (which the Arabians call 


1 Keonomic Geology of India, pp. 429, 529. 


114 Scientific Proceedings, Royal Dublin Society. 


yakut), hyacinths, granats, smaragds, chrysolites, amethysts, agats, 
Bezoar stones, and borax. Some places yield gold and silver and 
all manner of other metals.” 

"Many of these minerals, it is believed, do no not occur in lees 
proper, and the term therefore is probably used in a very extended 
sense, and hence misconception has arisen no doubt. On page 157 
he makes a remarkable statement, which might be used in support 
of the view contested in an early part of this Paper, namely, that - 
India received a// her gold from abroad. He says ‘“ Hindostan 
(by which, perhaps, only the realm of the Great Mogul is meant) 
possesses great quantities of gold and silver; but all is brought 
thither by strangers, never returning out again, for they melt down 
the Beisoigeet or foreign coins, and recoin them with the ser 
stamp.” 

In a map, published by Wells in 1700, the positions of the 
diamond mines of Coulour and Raolconda are given with much 
greater accuracy than is the case in Rennell’s map, published at 
the close of the eighteenth century. I was, however, confirmed in 
my conclusion as to the identification of the former by a manu- 
script map by Col. Colin MacKenzie, dated 1798, which is pre-_ 
served in Calcutta. 

In the maps of both Ogilby and Wells, Narsinga, a place often 

mentioned in the early accounts, is indicated as being situated to 
~ the east of Bisnaguar (i.e. Vijayanagar). 

Hamitron.—Captain Hamilton, who traded in the Hast Indies 
between the years 1688 and 1728, is our next authority.! He in- 
forms us that iron was made into anchors at Balasore, apparently by 
Huropean methods: if so, this was the first manufacture of that kind 
in India of which there is any record. He quotes a curious story 
as ‘to mercury having been brought to Achin in Sumatra from the 
Andaman Islands by a native, who, having been held for some time 
as a slave, was allowed to revisit his country on several occasions, 
and after each returned with some mercury which, he stated, was 
obtainable there (¢. e. probably in the Little Andaman). This state- 
ment, together with a consideration of the geological structure, has 
led me to suggest the possibility of a future discovery of the metal 
in the islands of the Andaman group. In age and in characters 


‘ New Account of the East Indies, vol. i., chap. xxix. Maderas or Chinapatam. 


~Batt—A Geologist’s Contribution to the History of India. 115 


there appear to be several points of resemblance between some of 
the Andaman rocks and those which contain le valuable CT 
mines of California. 

“The diamond mines, being but a week’s journey from Fort 
St. George, make them pretty plentiful there ; but few great stones 
are now brought to market there, since that great diamond which 
Governor Pitt sent to England. How he purchased it, Mr. Glover, 
by whose means it was brought to the governor, could give the best 
account, for he declared to me that he lost 3000 pagodoes by intro- 
ducing the seller to Mr. Pitt, having left so much money. in Arcat 
as security, that if the stone was not fairly bought at Fort St. 
_ George, the owner should have free liberty to carry it where he 
pleased for a market; but neither the owner nor Mr. Glover were 
pleased with the governor’s transactions in that affair.”’! 

“Some customs and laws at the mines are: when a person goes 
thither on that affair he chooses a piece of ground, and acquaints 
one of the king’s officers, who stay there for that service, that he 
wants so many covets of ground to dig in; but whether they agree 
for so much, or if the price be certain, I know not. However, 
when the money is paid the space of ground is inclosed, and some 
sentinels placed round it. The king challenges all stones that 
are found above a certain weight—I think it is about 60 grains; 
and if any stones be carried clandestinely away above the stipu- 
lated weight, the person guilty of the theft is punished with death. 
Some are fortunate, and get estates by digging, while others lose 
both their money and labour.” 

The remaining two authorities among those Buropeans who 
personally visited the mines they describe were, Mustapha,’ a 
Turk, who traversed the ‘diamond-bearing region of Chutia - 
Nagpur in 1758, and Motte,» who was deputed by Lord Clive 
in 1766 to purchase diamonds at Sambulpur, on the Mahanadi. 
The facts they record are chiefly of interest: as proving the exist- 
ence of the industry at those periods, and need not be further 
dwelt poe here. 


! A different version of the transaction by Mr. Pitt himself was published after his 
death. 
* Oriental Repertory, vol. ii. p. 261. London: 1808. 
3 Asiatic Annual Register. London: 1799. 
SCIEN. PROC. R.D.S.—VOL. LV. PT. II. L 


116 Scientific Proceedings, Royal Dublin Society. 


In recapitulation of ‘the conclusions which I have been led to 
as the result of this analysis of the facts recorded by the above- 
quoted writers, the following may be enumerated :— 

First. The great antiquity of the knowledge possessed by the 
natives of India with reference to certain metallurgical processes, — 
is, I think, fairly established. The most notable of these is, un- 
doubtedly, that by which wootz or cast steel. was manufactured. 
Probably the method of refining gold which is mentioned in the 
Ain-i-Akbari is also very old; but we have no earlier record of it. 
I question the accuracy of a statement made by Strabo, or at least 
its applicability, even in his time, to the whole of India, where he 
says, “The Indians, unacquainted with mining and smelting, are © 
ignorant of their own wealth.” 

Second. Many ancient, long-forgotten mines, the names of which, 
only, have survived in more or less archaic garbs, have, by the methods 
here adopted, been identified with modern sites.. In most of these 
cases geological evidence has established these conclusions, and in 
_ some instances they have been further ratified by local traditions 
acquired as the result of personal inquiries. 

Third. Several fables of world-wide notoriety have been shown 
to have had their origin in facts connected with ‘customs which were 
formerly little understood, but, being still in practice, are now sus- 
ceptible of close examination and explanation. 

Speaking generally, I venture to believe that I have in this 
Paper placed within the reach of historians a number of facts that 
serve to elucidate several subjects hitherto manifestly puzzling to’ 
_ those unacquainted with the results which have been arrived at 
by the systematic examination of the Geology of India. 


reer al 


XV.—REPORT ON THE FLORA OF THE WEXFORD AND 
WATERFORD COASTS. By H. C. HART, B.A. 


[Read, May 21, 1883.] 


On the evening of the 27th of July I reached Wexford, and on the 
following morning took boat across the harbour to Rosslare Point. 
This is the northern extremity of a long spit of sand between the 
harbour and the sea, and here commences the Wexford coast-line 
south of the harbour. In 1881 I had examined the coast-line 
northwards to Arklow, starting at Raven Point, which lies oppo- 
site to Rosslare on the north; and my explorations there, connected 
with those I am about to describe, include the entire coast-line of 
Wexford and Waterford, with the exception of the muddy shores 
of the larger estuaries, which I usually left untouched. These are 
chiefly occupied by towns, and easy of access, and have, no doubt, 
been frequently examined. I also spent a day upon the Saltee 
Islands, off the south coast of Wexford, where I made some inter- 
esting discoveries, and a list of the plants. In this summary of 
the distribution of plants on the south-eastern shores of Ireland I 
shall make use of a previous Paper of mine on the subject.! My 
observations of the spring plants are but scanty, depending on a 
walk from Courtown to Wicklow in May of the present year 
(1888). | , 

July 28. At the extremity of Rosslare Point is a pilot 
tower and a coastguard station. In the neighbourhood of these I 
found Lyciwm barbarum and Anchusa officinalis, both apparently 
established. The latter I have not seen recorded nor met with in 
Iveland before: the former is thoroughly naturalized in several 
places on the east coast. Here also I noticed Hehium vulgare, Ballota 
nigra, and Elymus arenarius, probably introduced also. I have doubts 
about E/ymus arenarius being a native species on the Wexford coast, 
which will be dealt with subsequently. In this locality it does not 
occur off the cultivated patches of land, and has not even spread over 
the surrounding sand-hills. The native sand-hill species at the ex- 


1 See Journal of Botany, November, 1881. 
SCIEN. PROC. R.D.S.—VOL. 1V. PT. I. M 


118 Scientific Proceedings, Royal Dublin Society. 


treme point were: Eryngium maritimum, Cakile maritima, Arenaria 
peploides, Euphorbia paralias, Viola curtisii, Carduus pycnocephalus, 
Senecio jacobea, var. flosculosus, Convolvulus soldanella, Salsola kali, 
Oynoglossum officinale, and other commoner species. About a quarter 
of a mile southwards I gathered Trifolium arvense, Apargia hispida, 
and Festuca uniglumis; these were chiefly on the harbour side of 
the spit of sand. Lavatera arborea and Hyoscyamus niger were also 
seen near the station; the former not native, the latter very uncer- 
tain, and casual in its appearance. About half a mile from the 
point Juncus acutus first appears, and at a mile down it is abun- 
dant on the harbour side. The outer shore is here a complete 
waste of shifting sand. On the harbour side I also noticed Phlewm 
arenarium, Erythrea vulchella, Carlina vulgaris, Ginanthe lachenalit, 
Carex distans, and Carex extensa. The latter was growing in a 
remarkable manner, erect amongst the tussocks of Juncus acutus 
to a height of 18 or 20 inches. Hrythrea pulchella is a rare 
species, which has not, I think, been gathered south of Curracloa, 
in Ireland previously. Here also I noticed abundance of Ero- 
dium maritimum and Chlora perfoliata in fields where the neck 
of land has widened. On_ this light sandy soil the most pro- 
minent species, especially on the ditch-banks, were Salix repens, 
Lychnis vespertina, Filago germanica, and Filago minima. I gathered 
here a curious-looking Filago, which at the time I thought might 
have been a hybrid between these two species; but I unfortunately 
lost the specimen. Vicia angustifolia is also frequent here. Here 
again was a small quantity of Elymus arenarius, this time on ditch- 
banks of a potato garden close to a cottage. About three miles 
from the point are higher sand-hills, and amongst these, east of 
Rosslare House, I observed Solanum nigrum, Chenopodium rubrum, 
Agrimonia eupatorium, Pastinaca sativa, Reseda luteola, Ballota mgra, 
Anthemis cotula, and others already mentioned. Solanum nigrum 
is a very rare plant in Ireland, for which I was glad to find a new 
locality. Pastinaca sativa wears the appearance of a native here, 
but is probably introduced. In ditches near this I gathered Equ- 
setum maximum. Here there is a small village on the shore, and 
at this point Juncus acutus disappeared for the present: Hrodium 
maritimun is still common. 

Having left Rosslare, the coast becomes a steep, low bank for 
about two miles to Greenore Point, similar to the marl banks north 


Hart—Filora of the Wexford and Waterford Coasts. 119 


of Curracloa to Blackwater. Along here Stnapis nigra is very fre- 
quent, and, I should say, undoubtedly native; as such it is very 
rare in Ireland. Along these banks, where the coast sweeps round 
eastwards, about half way between Rosslare and Greenore, I 
gathered Helminthia echioides, Linum angustifolium, and Convolvulus 
arvensis. On the north side of Greenore Point a small patch of 
Elymus arenarius occurs in a less suspicious-looking locality than 
the others. Here, too, I gathered Carex vulpina, Senebiera corono- 
pus, and Stachys arvensis, and at the point Festuca arundinacea and. 
Polygonum raii. A little south of Greenore, Hrodium moschatum 
and Orithmum maritimum occur—the former in doubtfully native 
circumstances. Along this coast Inula dysenterica is a characteristic 
plant, being remarkably abundant. From Greenore Point to Carn- 
sore Point, or “Carn,” as it is called in the neighbourhood, the 
coast is low, and at first sand-hills with a beach of porphyry, then 
red granite. A little south of Greenore I first met with Salvia 
verbenaca, on the Wexford coast. It occurred again nearer to Carn, 
and I noted, too, Poa rigida, P. loliacea, Cerastium senrdecandrum, 
Oynoglossum officinale, Beta maritima, and Gilaucium luteum, on the 
coast at St. Margaret’s. At Nethertown, Artemisia absynthiun, 
afterwards frequent, was first met with. It never occurs on the 
wilder part of the coast, or far from cultivation, and is, no doubt, 
introduced. Here, too, I gathered Apiwm graveolens. It was now 
dusk, and time to look for accommodation for the night. With 
some difficulty I obtained a bed at the post-office at Churchtown. 
I may mention, lest it should be thought the ways of botanists are 
those of unmixed recreation, that my fare for this tour was of a 
most meagre description, and, with very few exceptions, I shouid 
have preferred to pass the night on foot rather than in the only 
places I could find to sleep. However, the people did their best, 
and the lobsters, the staple article of diet, were excellent. 

July 29. About Churchtown I observed Apiwm graveolens, 
Erodium moschatum, Lamium incisum, Ginanthe crocata, and Cyno- 
glossum officinale ; and at the shore at Carn, Convolvulus soldanella, 
Erodium maritimum, and Euphorbia paralias were abundant. I was 
now fairly round the south-east corner of Ireland. The Saltee 
Islands were in view before me. This part of the cost is extremely 
lonely and desolate. For a mile or so, sand-hills bordering the sea 
on one side, and a tract of sheep pasture inland, yielded nothing 

i M2 


120 Scientific Proceedings, Royal Dublin Society. 


fresh. JI now reached the narrow bank of sand which separates 
Lady’s Island Lake from the sea, a lake abounding in ducks, 
black-headed gulls, and other wild-fowl. This lake has no outlet, 
and as it is of considerable size, about ten miles in circumference, 
and receives much drainage and many small streams, it causes 
occasionally most injurious floods. When these become past en- 
durance, the inhabitants of the country round assemble, and in 
a few days succeed in cutting a channel through the sand to the 
“big sea.” This is soon again filled up: when I was there it had 
not been open for two years, and the flood was then considerable. 
The plants of this lake betray its brackish tendency. Such un- 
usual conditions were not to be passed over, and I determined to 
make a complete circuit of the lake. On the bar at the eastern side 
of the lake on the sea-margin I found Diotis maritima, the sea cotton- 
weed, one of the rarest Irish plants, very beautiful with its snow- 
white woolly foliage, and conspicuous at a considerable distance. 
It grows on the barest sandy shores with scattered plants of bent, 
sea bindweed, and sea spurge. A barren gap occurs, the part where 
the channel is at times cut through, and then in a few hundred 
yards Diotis occurs again abundantly on the margin of the lake at 
its seaward end, and along the coast for about a mile to the bar of 
Tacumshin Lake, another brackish inlet. This plant is found at 
one place on the Kerry coast, and another in Waterford, Bally- 
heigh, and Tramore respectively. In England, according to Watson, 
it is now nearly extinct on the south-western shores. It was first 
recorded from the present site by Mr. John Waddy, and has since, 
I believe, been more accurately traced by Mr. Kinahan. On the 
coast below Lady’s Island Lake I also gathered Raphanus maritimus. 
On the eastern margin of the lake the following plants were noticed 
in the order mentioned :—Cinanthe lachenalii, Potamogeton pectina- 
tus, Zannichellia palustris, Ranunculus baudotii, Bidens cernua, Rumex 
- hydrolapathum, Lycopus éuropeus, Carex ovalis, C. hirta, C. extensa, 
and other commoner sedges and marsh species, to about the middle 
of the eastward shores of the lake, half a mile from a village. 
Here I discovered Rumex maritimus sparingly, but afterwards plen- 
tiful, especially on the northern shore abreast of Lady’s Island. 
This is an important new habitat. RL. maritimus grows abundantly 
at a long-known station, that of Garristown bog in Dublin, where 
L observed it immediately after ihe tour I am now describing. 


Hart—Filora of the Wexford and Waterford Coasts. 121 


Elsewhere in Ireland it is only known sparingly from Kilcoleman 
bog in Cork. Continuing my notes, I met with Apium graveolens, 
Scirpus savit, Chenopodium rubrum, and Rumex hydrolapathum. The 
latter is abundant in many places, especially in neighbouring swamps 
on the west side of the lake. About Lady’s Island I noticed Arte- 
misia absynthium thoroughly established, Anthriscus vulgaris amongst 
the ruins on the island, Parietaria officinalis, Hquisetum maximum, 
Ginanthe crocata, Lepidium smithii, Lycopus europeus very abundant, 
and Anthemis nobilis. Saponaria officinalis is also established here. 
At Lady’s Island I found a “boycotted” publican ; here I rested 
for an hour, and heard his side of the “burning question.” I then 
made my way by the shores of the lake to the sea coast, almost 
to the point I left. I have already mentioned the distribution of 
Diotis maritima. Here the walking became very laborious, in soft, 
heavy sand, along the narrow strip between Tacumshin and the sea. 
The plants I noticed, rapidly diminishing, were: Glaucium luteum, 
Atriplex littoralis, Raphanus maritimus, and Polygonum aviculare, 
var. littorajis, forming mats three feet long. After a while I was 
alone on a sandy waste, a high bank of shingle and sand forming 
a bar between the lake and the sea. I had gone a little way round 
the shore of this lake at first inland, but it was low, flat, and 
muddy, and the long strip of sandy coast looked more promising. 
What was my horror, after about two hours’ wearisome labour, to 
find a swift blue torrent, over a hundred yards across, foaming out 
of the lake into the surge of the sea. It was out of the question 
to go back. I would have lost a whole day by doing so, and 
nothing would have induced me to face that sandy trudge again. 
There was neither boat nor human being in sight. I felt evilly 
disposed towards several persons who knew where I was bound for, 
and had not intelligence enough to warn me, and especially to- 
wards the Ordnance Map, which is quite out of date for this 
changeable coast. On the map is marked a channel from Lady’s 
Island Lake, and a continuous coast outside Tacumshin. The 
reverse is the true state of things. With some misgivings, I 
resolved to swim. This necessitated three journeys: one with my 
knapsack, which I emptied on the opposite side; one back with it 
- empty, and a third with my clothes, boots, &e., in the knapsack. 
The knapsack floated bravely, and I towed it with a strap in my 
teeth. Hach time I started about forty or fifty yards higher up 


122 Scientific Proceedings, Royal Dublin Society. 


the current than the point opposite; but the third time, whether I 
was tired, or the knapsack was very much heavier, I was carried 
well into the strength of the current at the bar, and began to 
wonder how far it was to Cardigan Bay. However, I accom- 
plished the transport and resumed the journey. A few miles more 
brought me to a clean little inn at Kilmore. On the way I noticed 
Erodium maritimum and Atriplex littoralis. Through the courtesy 
of the chief boatman at the Coastguard Station I was able to make 
arrangements that night for a day on the Saltee Islands, of whose 
botany I had seen no report. 

July 30. A tolerably early start in the Coastguards’ boat, 
manned by four able men, brought me in about an hour to the 
great Saltee Island, which lies south of Kilmore, and about four 
miles distant. ‘The lesser island, about half the size of the greater, 
is a mile and a-half nearer shore. It is a third of a mile in width, 
and three-quarters in length. Greater Saltee is, roughly speaking, 
the same width and twice that length. A line drawn north-east 
and south-west would, approximately, form the greater axis of 
both islands. They are composed chiefly of gneiss and other hard 
metamorphic or Cambrian rocks. I met with no limestone. Con- 
sidering their small size, the flora is varied, and some very interest- 
ing varieties occurred. ‘There are no shrubs or trees. On the 
larger island Linaria elatine was gathered on the shingly shore 
below cultivated fields, about half a mile south of the landing- 
place. This plant has been found previously in very few locali- 
ties, chiefly in the county Cork. At the south-western extremity 
of this island I was pleased to meet with Radiola millegrana, very 
rare in the south-east of Ireland, and not gathered in this district 
before. Chenopodium rubrum occurs here, indisputably native, in 
characteristic abundance. It may be seen in quantity amongst the 
rabbit-holes and rocky ground at the barren south-eastern corner of 
the island. This plant is very rare and local in Ireland, and chiefly 
occurs on the Wexford coast; nowhere, however, so commonly as ° 
in the present situation. Inula crithmoides is also a characteristic 
plant, occurring in several places, always on the east side of the 
island. This has not been noticed along the Irish coast in this 
district before, its nearest recorded stations being Howth on the 
north, and Ardmore on the west. A few other interesting plants 
were noticed: Stachys arvensis and Anthemis cotula are very fre- 


Harr—fora of the Wexford and Waterford Coasts. 128 


quent in the corn fields. Crithmum maritimum, Beta maritima, 
Erodium maritimum, Laniwn amplexicaule, Hypericum elodes, and 
Euphorbia paralias were also observed. On the smaller island, 
Ginanthe crocata, Egquisetum maximum, and Tussilago petasites 
occur, which were not noticed on the greater Saltee. On the 
two islands a hundred and fifty-two species were observed, about 
a dozen of which, perhaps, are introduced. Of these a detailed 
list is appended. A few more, no doubt, occur, for whose observa- 
tion another visit would be requisite. 

A list of the species observed on the two islands will be 
appended to this Report. The great island is a home for breeding 
sea-fowl, chiefly puffins, which resort here in astonishing numbers. 
At the south-western corner of the island the ground by the edge 
of the cliffs and near them is trodden as bare as asphalt, and rid- 
dled with holes for a considerable area by this species. I observed 
rock-pigeons, oyster-catchers, herring-gulls, lesser black-backed 
gulls, guillemots, razor-bills, shags, and kittewakes. I was informed 
’ by the farmer in charge of the island that ravens, peregrines, 
greater black-backed gulls, and a few pair of sheldrakes also breed 
annually. At the time of my visit the birds had for the most part 
left the island, but a very considerable number still remained with 
their young. The birds are not allowed to be molested. On this 
island, which is partly cultivated, there is a resident family. The 
lesser Saltee is used as pasturage, and contains but one cabin for 
the occasional use of herd-boys. 

July 31. I left Kilmore early, and after rounding Crossfar- 
noge Point there lay before me a long stretch of sandy coast form- 
ing Ballyteigue Bay, and beyond, the low rocky shore stretching 
south to Hook Head. On the inside of the sand-hills a parallel 
dyke has been cut for drainage from brackish overflows and 
salt lakes. ‘This reaches about three miles, and I examined it as 
well as the barren coast outside, continually crossing and zigzag- 
ging backwards and forwards. The plants met with were : Hrodium 
maritimum, Viola canina (Liun.), Convolvulus soldanella, Carlina vul- 
garis, and in the canal, Zannichellia palustris, Potamogeton pectina- 
tus, Carex vulpina, Myriophyllum spicatum, Scirpus tabernemontant, 
and others. On the sandy ground, about two miles from the 
point, Ononis arvensis, Senecio jacobea, var. flosculosus, and Euphor- 


124 Scientijic Proceedings, Royal Dublin Society. 


bia portlandica were gathered. ‘The latter is much rarer than £. 
paralias along the Wexford shore. On these sand-hills, Rosa pim- 
pinellifolia is the most abundant plant; Rubus cesius also occurs. 
About a mile east of the Coastguard Station, and about five miles 
west of Crossfarnoge Point, I first met with the rare Asparagus 
officinalis. This is probably the locality recorded by Mr. Lewis in 
Mr. More’s recent addition to the Flora of Ireland. It occurs here 
sparingly, perfectly prostrate, and would easily be overlooked. 
Further on I found it at the sandy spit outside the salt water 
lough abreast of the Coastguard Station. Here also I gathered 
Hyoscyamus mger, Glaucium luteum, Lycopsis arvensis, Chenopodium 
yubrum, Carduus pycnocephalus, Solanum nigrum, Viola canina, Beta 
maritima, Erodium maritimum, and EH. cicutarium. Of these, the 
Henbane was very plentiful, and So/anwm nigrum occurred in some 
quantity. 

Here I hailed the coastguards, and got ferried across the “ Bar 
of the Lough”; the only name'I could learn for this interesting 
locality. The botany of this remote neighbourhood would, I 
imagine, well repay further research. Near this, Lythrum hysso- 
pifolium has been discovered in its only Irish locality. I searched 
for it along the banks and swamps of a small stream, a little east 
of Ballymadder, which is, I believe, the reported station, but with- 
out success. It is a very rare and uncertainly distributed plant. 


Along this stream, Rumex hydrolapathum and Carex acuta grow © 
) Y U]. 


plentifully. Close to it were seen MMalva moschata, Apium graveo- 
lens, and Senebiera coronopus. Along the coast here, and on Ban- 
now Island, Convolvulus arvensis is a common species. The eastern 
channel to Bannow Island is silted dry, or nearly so, with sand. 
On Bannow I gathered Centaurea scabiosa, Apargia lspida, Hyoscy- 
anus niger, Torilis nodosa, and others; and on blufis along the sea- 
ward face, Asparagus officinalis, a new locality for this very rare 
species already mentioned. It was blowing a gale of wind, and 
there was much difficulty in inducing an aged couple to ferry me 
across the estuary. This voyage accomplished, in the frailest of 
crafts, I made my way to Fethard. On the way I noticed Sta- 
chys arvensis, Pastinaca sativa, Centaurea scabiosa, and Origanum 
culgare. I reached Fethard at about four in the afternoon, and 
having arranged for accommodation for the night, I determined 


Hart—Fora of the Wexford and Waterford Coasts. 125 


to cut off a piece of my next day’s walk round’ Hook Head, which 
looked somewhat alarming. About Fethard I gathered Scandiz . 
pecten-veneris, Tanacetum vulgare, Lychnis githago, Apium graveo- 
lens, Juncus glaucus, and Ginanthe crocata. South of Fethard, by 
the roadside, Chenopodium bonus-henricus occurs. Along the coast, 
which is here of low slabs and schistose cliffs to Baginbun Head, 
I gathered Sarothamnus scoparius, Orithnum maritimum, Atriplex 
angustifolia, Statice occidentalis, Chiora perfoliata, Eupatorium can- 
nabinum, Epilobium hirsutum, and Eguisetum maximum. Statice 
occidentalis has not been previously gathered nearer than Arklow 
in Wicklow to the north, and Tramore in Waterford to the west. 
At Baginbun Head, Inula ecrithmoides occurs with Statice occiden- 
talis again. The promontory of Hook appears to have never been 
visited by a botanist. A little south of Baginbun, Ulex ewropeus 
and Ulex nana, both decorate the coast, the latter being -hence- 
forward a prominent coast species. On dry banks along here I 
found Senebiera didyma, afterwards a prevalent species. From 
Carnivan Head I returned by road to Fethard. 

On the Ist of August, I took up the coast again at Carnivan 
Head. The cliffs are now somewhat steeper, 50 to 100 feet in 
height, of a red horizontally-stratified sandstone and conglomerate. 
Along here, choughs and rock-pigeons were met with; of the 
former, perhaps, their most eastern locality in Ireland, except in 
the north. On the margin of these cliffs, on grassy banks a little 
south of Carnivan, I gathered Trifoliwm scabrum in an intermediate 
station between Youghal and Wicklow, its nearest previously- 
known habitats. A very glaucous form of Dactylis glomerata, 
which I have gathered on Mweelrea, in Mayo, grows here plenti- 
fully. About Sandeel Bay, I first met with Rubia peregrina, 
aiterwards becoming frequent. Howth, in Dublin, and Tramore, 
were its nearest known stations. Huphorbia exigua and Hyoscyamus 
niger were noticed along Sandeel Bar. Here the sandstone con- 
glomerate is overlaid by a highly fossiliferous carboniferous lime- 
stone. Polygonum ravi grows along here commonly to Patrick’s 
Bay; and nearer to Churchtown, Inula crithmoides and Statice 
occidentalis again appear. The former is very plentiful on the low 
rocky coast, right round the long, narrow point of Hook, and at 
the very point Statice occidentahs is abundant. 


126 Scientific Proceedings, Royal Dublin Society. 


The scenery along here is delightful, and one obtains an exten- 
sive prospect of coast and sea at the point of Hook. There is a 
feeling of remotenesss and loneliness about this oddly-left streak 
of rocks which one hardly expected to find in the county of Wex- 
ford, and which is rather heightened by that monstrous uninhabited: 
palace, Loftus Hall—an edifice which the natives maintain is “‘the 
largest in the kingdom, except one in London”; and, judging 
from appearance, they may not be far astray. For four miles this 
point is about half or three-quarters of a mile in width, utterly 
exposed, and unable to produce timber except the lowest scrub. 
The soil is of the poorest description, and harbourage for boats 
there is none. A few cottagers and fishermen exist, and here 
stands the largest palace but one in the kingdom! [I heard it 
had been once visited, but never inhabited, by its owner. About 
Churchtown Senebiera didyma was again observed, and along the 
coast S. coronopus formed the sward in many places. At the Point 
Crithmum maritimum and Aster tripolium abound. Near a limekiln, 
on the water side of the Point, I gathered Atriplex littoralis, Hro- 
dium maritimum, and Cochlearia danica. About half a mile north of 
the lighthouse, Inula crithmoides ceases to grow. Statice occidentalis 
was not seen past the Point. About a mile and a-half north of the 
Point, immediately below Loftus Hall on the west side, I found a 
single patch of Trifolium fragiferum. ‘This is the only place I met 
with this species in the county, and there must be some mistake in 
the record in the “‘ Recent Additions,” ‘“‘ common near the sea, in 
Wexford.” Perhaps it should stand near the town of Wexford ? 
It may occur in the Waterford or Wexford estuaries, which I 
hardly botanized, but is certainly not common. A few miles 
further brought me well into the Waterford estuary, and I found 
no plants of interest. On the supposition that I was nearing a 
large town, and in places easy of access and well explored, I aban- 
doned the coast from Duncannon to Tramore. Along the road- 
side, a little south of Duncannon, I noticed Helminthia echiordes, 
Chiora perfoliata and Juncus glaucus; and at Duncannon Salvia 
verbenaca, Dipsacus sylvestris, Pastinaca sativa, and Senebiera didyma. 
This is a second locality for Helminthia echioides, a rare plant not 
previously noticed in the district. 

Having crossed the estuary from Ballyhack to Passage by 


Hartr—Flora of the Wexford and Waterford Coasts. 127 


ferry-boat, I was out of District 4 and into District 2 of the 
“ Cybele Hibernica.”” At Passage I observed Artemisia absynthium 
and Centranthus ruber, the latter an ornament to the rocks. 
Between Passage and Waterford, which I travelled by mail car, I 
observed Scrophularia aquatica, common in many places in Water- 
ford, but a locally-distributed plant. 

August 2. Along the railway between Waterford and Tra- 
more Malva moschata and Equisetum maximum were noticed. The 
sand-hills east of Tramore are a known habitat for Juncus acutus 
and Diotis maritima. I started westwards along the cliffs south- 
west of Tramore, keeping continually in mind, as I had done since 
I left Wexford, that it was necessary to examine all stony beaches 
for Huphorbia peplis, which has appeared occasionally on this coast. 
Moreover, Erica vagans has been stated to occur on the cliffs west 
of Tramore. Along the cliffs immediately west of Tramore I 
noticed Rubia peregrina, Inula crithmoides, Statice occidentalis, and 
Crithmum maritimum, to Newtown Head or “The Metal Man.” 
On the cliffs beyond Newtown Head I met with Lavatera arborea 
in a thoroughly wild station. Inula crithmoides and Rubia pere- 
grina are very frequent along here: Lavatera arborea and Statice 
occidentalis occur more sparingly. Here I came to the first acces- 
sible beach, a little on the Tramore side of Garraris Cove, the 
locality in which Huphorbia peplis has been discovered. On this 
beach I was struck with the strong resemblance which young 
leaf-shoots of Gilauciwm lutewm bear to those of Diotis maritima: 
the latter, which was fresh in my memory, is somewhat whiter. 
For some distance I kept the base of the cliffs in search of Kuphor- 
bia peplis but without success. It will suffice to say that I ex- 
amined every beach from T'ramore to Youghal more or less carefully, 
especially those between Tramore and Dungarvan, and was much 
disappointed to find no trace of this very rare and uncertain 
species. I questioned fishermen, boatmen, cockle-gatherers, and 
dulse and carrigeen women, in many nooks and corners. It was 
easy to learn from these accommodating Celts that the plant was 
usually abundant: milky juice, red foliage, and all peculiarities 

unmistakably described—after they were informed of them. One 
- woman in Garraris Bay assured me she knew it, but that like 
everything else along the shore it was “tore out of it’’ by the 


128 Scientific Proceedings, Royal Dublin Society. 


terrible storms of September and October, 1881. Perhaps she was 
right, since the plant grows on the margin of the tide. The 
trudging for miles along the heavy shingly shore at the base of 
the limestone cliffs, between Kilfarrasy Isiand and Annestown 
was a thing never to be forgotten. On the other hand, the first 
few miles along the cliffs south of Tramore is as thoroughly enjoy- 
able a sea-coast walk as one could wish to repeat. At Kilfarrasy 
Island I gathered Trifolium arvense, a very thinly-distributed 
species in its native stations, but one which increases quickly on 
light sandy cultivated soil near the sea. Here it occurred sparingly 
on steep banks. On the sheer limestone cliffs just mentioned 
Raphanus maritimus 1s a very characteristic species. I have not 
seen it so satisfactorily a member of the flora in any other district. 
At Annestown, a small and very prettily-situated group of cot- 
tages, I was hospitably entertained at lunch by Mrs. Palliser, wife 
of Major Palliser, the owner of the soil, who saw me irom their 
dwelling-house near by, searching the village for refreshment, 
and, with thoroughly appreciated kindness, invited me in. Along 
banks above the sea, at Dunabrattin Bay and about Annestown, 
Senebiera didyma looks wild enough. Inula crithmoides and Rubia 
peregrina both occur at Dunabrattin Head, and here again I 
met with the chough. About half way between Annestown and 
Knockmahon Statice occidentalis and Raphanus maritimus were again 
observed, the latter abundantly. The rock is chiefly a slaty lime- 
stone, and nearer to Bunmahon, where mining operations to a 
great extent were formerly carried on, gives place to red hematite, 
&c. Near the shore here, in a swamp, I gathered Ginanthe fistulosa, 
a plant I seldom meet with, though said to be frequent. At Bun- 
mahon, a melancholy wreck of deserted cottages, heaps of rub- 
bish, disused rails, mining shoots and properties of all kinds, I 
found a remarkably spinous form of Ononis arvensis, large and 
erect, and readily liable to be mistaken for O. campestris. A little 
beyond Bunmahon Rubia peregrina is very abundant. 

August 3. Beyond Bunmahon the coast is precipitous, and 
beautifully diversified with bays, stacks, and pinnacled islets. The 
cliffs here are for the most part sheer, 200 to 300 feet in height. 
The rock is at first. a dark slaty rock, and then red conglomerate, 
probably of the Old Red Sandstone formation. These cliffs are 


Harr—Flora of the Wexford and Waterford Coasts. 129 


inhabited by the peregrine falcon. Their margins are gay with 
Scotch heather, dwarf furze, lady’s finger, sea pink, and campion. 
Gentiana campestris was noticed as being very large. The travel- 
ling here was very laborious, and the weather had become oppres- 
sively hot. Headland and inlet in succession made the coast line 
beautiful no doubt, but very difficult to examine. At Bally- 
dowane Bay I gathered Rubia peregrina, Trifolium arvense; and 
a little west of it, by a small stream, Osmunda regalis and 
Habenaria viridis: nearer to Stradbally, Hguwisetum maximum 
and Artemisia absynthium were noted. On the cliffs west of 
the inlet below Stradbally, Ligustrum vulgare is abundant in 
perfectly native situations. It would, I believe, be hypercriti- 
cism to challenge the privet’s claim to a place in the native 
flora of Ireland. It extends along the coast here for about half 
a mile, commencing a quarter of a. mile west of the Stradbally 
inlet, and appears again in many places to Ballyvoyle Head. 
It grows in a semi-prostrate tangled form on the steepest and 
most inaccessible parts of the cliffs, where there are patches of 
soil. I have not seen privet native elsewhere in Ireland except at 
Howth, but Dr. Wright found it under similar conditions nearer 
to Tramore. At the Stradbally inlet I saw Orobanche hedere and: 
Carlina vulgaris. With the privet, Rubia peregrina has become 
very abundant along the coast to Ballyvoyle Head. Raphanus 
maritimus and Inula crithmoides still occur. By a small stream 
a little east of Ballyvoyle Head, I noticed Lepidiwm smithii, 
Lycopus europeus, Agrimonia eupatorium, Oarex remota, and Eupa- 
torium cannabinum. On Ballyvoyle Head, east side, Vicia 
‘sylvatica grows abundantly; on the west side, towards Ballyvoyle 
Bridge, Senebiera didyma, Carduus pycnocephalus, and Artemisia 
absynthium are plentiful. I had now reached the lowlands 
again, and was well pleased to see a considerable marsh be- 
tween me and Dungarvan, which would afford at once rest and 
variety. I found the flora of this marsh very interesting ; it is a 
small murrough, similar to that at Kilcoole, on the coast of Wick- 
low, but less extensive. It lies in the parish of Clonea, inland 
and eastward from Clonea castle. It does not appear to have 
been examined by a botanist previously to my visit. On the sea- 
ward edge I noticed Guanthe lachenalii and Carex vulpina. In 


130 Scientific Proceedings, Royal Dublin Society. 


heavy dykes and on their banks occurred Ruppia maritima, Scirpus 
tabernemontant, Carex acuta, Rumex hydrolapathum, Potamogeton 
pectinatus, P. pusillus, Juncus glaucus, Lycopus europeus, Typha 
latifolia, Utricularia vulgaris, Alisma ranunculoides, Poa aquatica, 
Ranunculus lingua, Myriophyllum verticillatum, Sium angustifolhium, 
Carex remota, C. stricta, and C. paniculata. Of this interesting 
assemblage of plants, some of which are very rare, the only record 
I find in the “Cybele” is that of Rumex hydrolapathum, noticed at 
Clonee by Wade. At the shore at Clonea may be seen Gilaucium 
luteum, Polygonum rati, Convolwulus arvensis, and Senebiera didyma. 
This latter species has as much claim, or I should be inclined to 
say, even more claim to be regarded as native than Senebiera — 
coronopus on the south coast of Ireland, so far as external appear- 
ances go. Further south I met with nothing of interest till I 
reached the lighthouse. Between that and the Coastguard Station, 
Helminthia echioides occurs, and here, as elsewhere, through the 
day, the prevalence of Geranium dissectum was noted. It is pro- 
bably native in this part of Ireland. rom this I obtained a boat 
across the harbour to Dungarvan, the dirtiest and most disrepu- 
table-looking town in Ireland. 

August 4. Having taken a boat for Helvick Head, five miles 
off, the outer and southern point of the harbour, I left Dungarvan 
early. On the way I landed at the Cunnigar, a long spit of sand 
stretching up from the southern side to the northward. Juncus 
— acutus, Polygonum raii, and Artemisia absynthium, were observed : 
the rush has previously been noticed here. At Helvick Head, 
where the coast becomes steep and mountainous in character, I 
met with Inula crithmoides and Trifolium arvense, as also some 
upland species, Solidago virgaurea and Molinia cerulea. A. mile 
southward, Osmunda regalis and Senecio sylvaticus were noticed, 
and Rubia peregrina is frequent along this coast. Hguise¢um maai- 
mum and Carduus pycnocephalus are also frequent. Inula crith- 
moides was met with all along to Ardmore. At Mime Head (a 
great resort for cormorants) Zifoliwm arvense occurs again; and 
Torilis nodosa, a rare species, is very frequent. Foxglove and oak 
oceur along these steep headlands in profusion, the latter in its 
stunted native form. Beta maritima is also a prevalent plant ; at 
Mime Head, too, I found a steep bank decorated throughout with 


Hart—Fiora of the Wexford and Waterford Coasts. 131 


the very local and handsome species Vicia sylvatica. At Bally- 
ernan, a few miles north of Ardmore, I found Linwm angustifolium, 
Juncus glaucus, Lychnis githago, Pastinaca sativa, Anthemis cotula, 
and Centaurea scabiosa. Close to Ardmore, Salvia verbenaca and 
' Scandix pecten-veneris were also met with. It was late when I 
reached the prettily-situated village of Ardmore. The day had 
been a roasting one, and the walking unusally severe, so that the 
most primitively conducted inn I have yet discovered was a wel- 
come object. Here I remained for the night. 

August 5. Ardmore Head, to the south of the village, is most 
picturesque and enjoyable. An early start brought me round the 
head and along the coast into Youghal by the ferry by two o’clock. 
Ardmore Head has been frequently botanized, and is rich in 
variety as well as rarities. J observed Solidago virgaurea, Arte- 
misia absynthium, Rubia peregrina, Vicia angustifolia, Centaurea 
scabiosa, Inula crithmoides, Cichorium intybus, Trifolium arvense, 
and others of less interest. West of Whiting Bay, Juncus glaucus 
and Apium graveolens were noted; and on the headland between 
that and Youghal Harbour at a small strand, I observed Glauciwm 
luteum, Euphorbia parahas, Linum angustifolium ; and a little far- 
ther, Filago germanica, Echium vulgare, Verbena officinalis, Verbas- 
cum thapsus, Rubia peregrina and Inula crithmoides. Opposite 
Youghal occur Feniculum vulgare and Calamintha officinalis, and, as 
in many other places previously, horse-radish has here established 
itself. Verbena officinalis and Calamintha officals are distinctly 
southern plants in Ireland, and are known to occur in many Cork 
stations, at which county I had now arrived. This county has 
been well explored by numerous botanists; and here I left the 
coast, and took a passage on the steamer up the Blackwater, 
to Cappoquin, and thence to Dublin. 

In the appended systematically-arranged list of my obser- 
vations, I have included localities noticed in the spring of the 
present year between Courtown and Arklow, as well as those 
already referred to in a Paper of mine in the “ Journal of Botany.” 
The plants enumerated are brought together to display the species 
which prefer the margin of the sea, as well as new localities for 
the rarer sorts; and, for facility of reference, I have included all 
the less common species observed. 


132 Scientific Proceedings, Royal Dublin Society. 


The following are additions to the Flora of the Districts in 
which they occur, as given in the “Cybele Hibernica”’ and its 
supplement :— 

Sinapis nigra (Linn.)—District 4. 
Raphanus maritimus (Sm.)—District 2. 
Lavatera arborea (Sm.)—District 4. 
Radiola millegrana (Sm.)—District 4. 
Rubus cesius (Linn.)—District 4. 

Rubia peregrina (Linn.)—District 4. 
Inula crithmoides (Linn.)—District 4. 
Carduus nutans (Linn.)—District 4. 
Helminthia echioides (Goert.) District 4. 
Orobanche minor (Linn.)—District 4. 
Chenopodium rubrum (Linn.)—District 4. 
Obione portulacotdes (Moq.)—District 4. 
Rumea maritimus (Linn.)—District 4. 
Carex acuta (Linn.)—District 2 and District 4. 


In this list one species, Blysmus rufus, is omitted, which I for- 
merly recorded from Raven Point. I have some slight doubts 
about its occurrence, since I could not find a specimen amongst 
my collections, and I think it better to leave it uncertain till an 
opportunity for further search occurs. 

The following flora contains a large proportion of the plants 
classed as Atlantic by Watson. More than half the total number 
found in Ireland occur on the coasts of Waterford and Wexford. 
Watson’s Atlantic group may be divided into two sets of plants: 
(1) littoral or maritime, which are confined to the coast; and (2) 
inland species, which, though chiefly affecting maritime counties, | 
are, In many cases, found far from the vicinity of the sea. ‘These 
two sub-groups viewed separately help us to appreciate the distri- 
bution of a considerable number of species in Ireland. The first is 
best represented on the east and south-east of Ireland ; that is to 
say, in the district under consideration, where, with one or two 
exceptions, all of them occur; the second predominates in the west 
and south-west of Ireland, and in this group of western species 
may be included several so-called ‘‘ Hibernian’”’ plants found in 
Kerry and Connemara, which do not occur in Britain, and are 
- therefore not dealt with in Watson’s “Cybele Britannica.” 


Hart—Flora of the Wexford and Waterford Coasts. 133 


The maritime Atlantic species on the Waterford and Wexford 
coasts are :— 


Matthiola sinuata. Tnula crithmoides. 
Raphanus maritimus. Statice occidentalis. 
Viola curtisil. HKuphorbia peplis. 
Lavatera arborea. Hi. paralias. 
EKrodium maritimum. HK. portlandica. 
(Daucus maritimus). Asparagus officinalis. 


Several of these do not reach the west. Scilla verna is the only 
strictly seacoast species of the group which I did not meet with, 
and my time of search was not sufficiently early for its discovery. 
It may occur, since it reaches the Wicklow coast, and is confined 
to the eastern and north-eastern coasts of Ireland. 

The other species of Watson’s Atlantic group on these coasts 
are :— 


Coronopus didyma. Sedum anglicum. 
Linum angustifolium. Cotyledon umbilicus. 
Hypericum androsemum. Rubia peregrina. 

H. elodes. Orobanche hedere. 
Krodium moschatum. Scirpus savii. 


Some of these are universally distributed in Ireland ; and most 
of them are, like the rest of this sub-group, commoner in or 
confined to the west of Ireland. The few Spanish and other 
south Huropean species which reach the west of Ireland, and are 
not dealt with in Watson’s classification, will be readily included 
‘in this sub-group of his Atlantic type. I refer to such species 
as Hrica mediterranea, Dabeocia polifolia, Pinguicula grandiflora, 
Saxifraga wmbrosa, ete., which form the extreme type of the 
British development of the groups. A division including the 
species Stbthorpia europea and Erica vagans will naturally embrace 
these also. The term Hibernian type is, I think, objectionable and 
unnecessary. 


[ Lora 


SCIEN. PROC. R.D.S.— VOL. IV. PT. I. ; N 


134 Scientific Proceedings, Royal Dublin Society. 


FLORA OF THE COASTS OF WEXFORD AND 
WATERFORD. 


[* Certainly introduced, but looking wild; { probably introduced; + perhaps intro- 
duced; [| doubtfully established, and not native. ] 


Thalictrum minus (Linn.), var. maritimum.—From a little north of 
Courtown to about three miles south of Cahore Point, amongst 
sand-hills. : 

Ranunculus lingua (Linn.)—Swamp by the coast at Clonea, near Dun- 
garvan in Waterford. 

Ri. sceleratus (Linn.)—With the last, and at Lady’s Island Lough, 
near Carnsore, Wexford. Not unfrequent, but chiefly in the 
estuaries. 

Ri. baudotti (Godron)—Lady’s Island Lake, at the south-eastern 
corner. 

Glaucium luteum (Scop.)—At Greenore, Tacumshin, Ballyteigue, and 
Bannow in Wexford; Gararis Bay, Ardmore, and near Youghal 
in Waterford. 

Mathiola sinuata (R. Br.)—Blackwater Head or Ballyconigar ; Tinny- 
berna, and about five miles north of Tinnyberna below Kilmuck- 
ridge. <A very rare species. 

Sinapis nigra (Linn.)—Steep banks above the sea between Rosslare 
and Greenore, Co. Wexford. I believe it:to be native here. 
Cochlearia officinalis (Linn.)}—Common. The sub-species C. danica 

(Linn.) occurs at the western side of Hook Head, Wexford, near 
the point, and nea Churchtown. 

*Armoracia rusticana (Rupp.)—Hstablished in many places, especially 
on the Waterford coast. ; 

Lepidium smithii (Hook.)—Lady’s Island, Co. Wexford, and a little 
east of Ballyvoyle Head, Co. Waterford. 

| Senebiera coronopus (Poiret.)—Greenore ‘Point, and from thence in- 
creasing in Wexford. Very abundant at Hook Head. Decreas- 
ing in Waterford, and occurring only as a waste-ground plant. 

+S. didyma (Pers.)—At Baginbun, near Fethard; about Churchtown 
and Duncannon in Wexford. Dunabrattin Bay, and about Annes- 
town; at Ballyvoyle Head, and elsewhere. More frequent in 
Waterford, and occurring in wilder stations than the last 
species. 

Cakile maritima (Scop.)—Frequent. 


Harr—Filora of the Wexford and Waterford Coasts. 185 


Raphanus maritimus (Sm.)—Coast beiow Lady’s Island, and between 
that and Tacumshin in Wexford; frequent on the steep lime- 
stone cliffs between Kilfarassy Island and Annestown, and again 
between Stradbally and Ballyvoyle Head in Waterford. 

Reseda lutea (Linn.)—On a headland at Tinnyberna, Co. Wexford. 

tola canina (Linn.)—Sandy ground west of Crossfarnoge Point, Wex- 
ford, plentiful. 

V. curtisti (Forst.)—Frequent where sand-hills occur. 

Saponaria officinalis (Linn.)—Hstablished at Lady’s Island, Wexford. 

Silene anglica (Linn.)—Tinnyberna in Wexford. 

S. maritima (1.)—Common. : 

Lychnis githago (liam.)—Sandy soil about the coast near Fethard in 

‘ Wexford, and about Ardmore in Waterford. 

L. vespertina (Sibth.)—About Rosslare, Wexford. 

L. diurna (Sibth.)—Very abundant at Courtown. 

Sagina maritima (Don.)—Frequent. 

S. nodosa (HK. Meyer.)—Frequent. 

Honkeneja peploides (Khrh.)—Sandy coasts. Frequent. 

Arenaria serpyllifolia (Linn.)—Not unfrequent. 

Cerastium tetrandrum (Curt.)—Frequent. 

C. semidecandrum (Linn.)—Between Greenore and Carnsore Point, and 
sandy shores at Courtown Harbour, and north of that to Arklow. 
No doubt frequent. See under Valerianella olitoria. ) 

Malva moschata (Linn.)—Cahore Point, and Lady’s Island in Wex- 
ford; Tramore and Ardmore in Waterford. 

}Lavatera arborea, (Linn.)—Kilmichael Point, Raven Point, and Ross- 
lare Point in Wexford; always in suspicious localities; west of 
Newtown Head in Waterford, looking wild along the cliffs. 

Hypericum elodes (Linn.)—Greater Saltee Island. 

H. androsemum (Linn.)—Oceasionally, especially on thickets on the 

‘Waterford coast. 

Hrodium cicutarium (Sm.)—Frequent. 

E. moschatum (Sm.)—Greenore Point and Churchtown in Wexford ; 
near Tramore in Waterford. 

EL. maritimum (Sm.)—Frequent all round the coast of Wexford from 
Rosslare to Hook Head, and especially abundant about Crossfar- 
noge. This species reaches a maximum on the Wexford coast ; 
in Waterford it has been found at Tramore (‘‘ Cyb. Hib.’’) I did 
not meet with it west of that village. 

Geranium dissectum (Linn.)—Quite a characteristic coast species in 


Waterford, and looking ELL which it generally does not in 
Ireland. 
N2 


136 Scientific Proceedings, Royal Dublin Society. 


Linum angustifolium (Linn.)—Between Curracloa and Blackwater, and 
between Rosslare and Greenore in Wexford; Ballyernan and Ard- 
more Head in Waterford. 

Radiola millegrana (Sm.)—Greater Saltee Island, Wexford. Very rare 
in the south-east of Ireland. 

_ Ulex gallii (Planch.)—A very characteristic species along the higher 
headlands and rocky coasts of Waterford. U. ew ‘op@us is remark- 
ably showy and common in most parts of Wexford, more especially 

_ inland. | 

Sarothamnus scoparius (Koch.)—Baginbun, near Fethard in Wexford, 
and west of Tramore and Stradbally in Waterford. Not frequent 
along the coast, and occurring in the prostrate form at Baginbun. 

~ Ononis arvensis (Linn.)—Locally plentiful, as on the sand-hills west of 
Crossfarnoge in Wexford, and about Bummahon and Knockmahon 
in Waterford, where a remarkably spinous form was gathered. 

Trifolium pratense (Linn.)—The red clover is very abundant along 
the marl banks on the Wexford coast, where it is probably indi- 

genous. 

Trifolium medium (Linn.)—Near Courtown in Wexford. 

T. arvense (Linn.)—Rosslare in Wexford; Kilfarassy Island, Bally- 
dowane Bay, Helvick Head, Mime Head, and Ardmore Head in 
Waterford. 

T. scabrum (Linn.)—A little south of Carnivan Head, near Fethard in 
Wexford. 

T. fragiferum (Linn.)—Below Loftus Hall, on the west side of Hook 
Head in Wexford. See earlier part in this Report. 

Lotus major (Scop.)—Saltee Island, Co. Wexford. 

Anthyllis vulneraria (Linn.)—Common. 

Vicia sylvatica (Linn.)—Duficarrig rocks, north of Courtown, Wex- 
ford ; at Ballyvoyle Head and Mime Head, Waterford. 

V. angustifolia (Roth.)—Courtown and Rosslare in Wexford ; Ardmore 
in Waterford. 

Ornithopus perpusillus (Linn.)—Has been patberen at Ballyconigar 
Wexford. See ‘“‘ Cybele Hibernica.”’ 

Agrimonia eupatoria (Linn.)—Below Kilmuckridge, and about Rosslare 
in Wexford; about Ballyvoyle Head in Waterford. 

Alchemilla vulgaris (Linn.)Sandy fields by the sea north of Rosslare 
in Wexford; rather an unexpected habitat. 

Rubus cesius (Linn.)—South of Cahore Point, and near Morris Castle 
on the east coast of Wexford ; and on the sand-hills west of Cross- 
farnoge Point on the south. 


Hart—Flora of the Wexford and Waterford Coasts. 187 


Rosa spinosissima- (Linn.) — Frequent ; usually abundant where it 
occurs. 

Lythrum hyssopifolia (Linn.)—See preceding part of this report. 

Epilobium hirsutwm (Linn.)—Between Fethard and Baginbun in Wex- 
ford, and elsewhere. 

Myriophyllum verticillatum (Linn.)—Marshy pools at Clonea, near Dun- 
garvan, Waterford. 

M. spicatum (Linn.)—In a brackish dyke inside of the sand-hills west 
of Crossfarnoge Point in Waterford. 

Lepigonum rupicola (Kindb.)— 

LL. salinun (Presl.)— Frequent. 

L. marinum (Wahlb.)— 

Sedum anglicum (Huds. )— \ 

S. acre. (Linn. )— | Common: 


Cotyledon wmbilicus (Linn.)—Not unfrequent where the coast is steep 
and rocky. 

Eryngium maritimum (Linn.)—Frequent. 

Apium graveolens (Linn.)—Not eee and occurring oftener on 
the south coast. 

Gnanthe fistulosa (Linn.)—Near Bunmahon, Waterford. Rather a 
scarce species in Ireland. 

GE. lachenalii (Gomel.)—Morris Castle, Slaney Estuary, Rosslare, and 
Lady’s Island Lake in Wexford. Clonea, near Dungarvan in Water- 
ford. Chiefly an estuary species. 

CE. crocata (Linn.)—Frequent, and partial to damp places along the 
coast, whether brackish or otherwise. 

Linum angustifoliun (Linn.)—Curracloa in Wexford, and Clonea in 
Waterford 

*Feniculum officinale (Ald.)\—Kilmichael Point, and Curracloa in Wex- 
ford. Coast opposite Youghal in Waterford. 

Crithmum maritimum (Linn.)—Common in many places, and occurring 
on low stony ground about three miles north of Courtown. 

t Pastinaca sativa (Linn.)—Curracloa, Rosslare, Fethard and Duncannon 
in Wexford. At Rosslare this species has the appearance of a 
native on the sand-hills. Ardmore, &c., Waterford. 

Daucus carota (Linn.)—Common. The variety maritimus occurs on 
the Waterford coast. 

Torilis nodosa (Gcert.)—Tinnyberna, and Bannow Island in Wexford ; 
Mime Head in Waterford. 

Anthriscus vulgaris (Pers.)—By the river at Lady’s Island, Wexford. 

Galium verum (Linn.)—Common, . 


1388 Scientific Proceedings, Royal Dublin Society. 


Rubia peregrina (Linn.)—Sandeel Bay, south of Fethard, on the pro- 
montory of Hook, Wexford ; on all the prominent bluffs and head- 
lands on the Waterford coast. 

Valerianella olitoria (Mcench.)—A dwarf form flowering in early spring ; 
erows abundantly on the sand-hills of Wexford, at Courtown, and 
elsewhere. It occurs similarly in Donegal, usually in company 
with Cerastium tetrandum, C.. semidecandrum, Draba verna, and 
Saxifraga tridactylites. The latter two, though occurring inland, 
do not appear to prevail on the south-eastern coast. In the 
north-west their ranges are reversed, and apparently confined to 
the coast, or nearly so. 

Dipsacus sylvestris (Linn.)—Duncannon in Wexford; at the town of 
Waterford. 

Eupatorium cannabinum (Linn.)—Baginbun, near Fethard in Wexford, 
and along the steep Waterford coast near Ballyvoyle Head and 
Stradbally, and elsewhere. 

Aster trifolium (Linn.)—Frequent. 

Solidago virgaurea (Linn.)—Helvick Head, Ardmore Head, &c., along 
the Waterford coast. 

Inula crithmoides (Linn.)—Greater Saltee Island, and Hook Head at 
the extreme point, plentifully, in Wexford; frequent along the 
Waterford coast. 

Pulicaria dysenterica (Goert.)—A very plentiful and characteristic species 
on damp, sandy pasture in many places. 

Matricaria inodora (Linn.), var. maritima.—Common. 

Diotis maritima (Cars.)—Sandy coast below Lady’s Island Lake, and 
Tacumshin Lake, Co. Wexford, extending for about an English 
mile. Also found at Tramore, Waterford. 

{Artemisia absynthiwn (Linn.)—Nethertown and Lady’s Island, Wex- 
ford; more frequent on the Waterford coast. Never in unques- 
tionable localities. 

Filago germanica (Linn.)—A frequent sand-hill species, especially 
common about Rosslare in Wexford. 

EF’. minima (Fr.)—Very plentiful, with the last at Rosslare. 

Senecio jacobea (Linn.), var. flosculosus.—Cahore Point, Rosslare, and 
‘“‘ Bar of the Lough,” on the Wexford coast. 

S. sylvaticus (Linn.)—Frequent on the moors along the Waterford coast. 

Carlina vulgaris (Linn.)—Cahore, Rosslare, and Crossfarnogue in 
Wexford; Stradbally in Waterford. 

Centaurea scabiosa (Linn.)—Bannow Island, and near Fethard in 
Wexford; Ardmore Head in Waterford. 


Harr—Flora of the Wexford and Waterford Coasts. 189 


Carduus nutans (Linn.)—On a headland by the sea near Tinnyberna, 
Wexford. 

C. pycnocephalus (Curt.)—Frequent. 

Cichorium intybus (Linn.)—Along the embankment on the north side 
of Wexford Harbour, and sand-hills adjoining, Ardmore Head, 
Waterford. 

Thrincia hirta (D. C.)—Frequent, especially on the dry marl banks of 
the Wexford coast. 

Apargia hispida (Willd.)—Rosslare, and Bannow in Wexford. 

Helminthia echioides (Gcert.)—Between Rosslare and Greenore, and 
near Duncannon in Wexford; between the lighthouse and the 
Coastguard Station, on the north side of Dungarvan Harbour, 
Waterford. 

Ligustrum vulgare (Linn.)—Stradbally, to Ballyvoyle Head, and else- 
where on the Waterford coast. 

Chlora perfoliata (Linn.)—Cahore to Ballyconigar, in several places 
on the sandy pastures, and at Carnsore and Baginbun in Wex- 
ford. 

Erythrea pulchella (Fries.)—Sand-hills between Rosslare Point and 
Rosslare, and on the Great Saltee Island, in Wexford. 

Ei. centauwrium (Pers.)—Common. 

Gentiana campestris (Linn.)—Abundant in some places, as at Raven 
Point in Wexford, and along the cliffs west of Bunmahon in 
Waterford. 

Convolvulus arvensis (Linn.)—Between Curracloa and Blackwater, and 
between Rosslare and Greenore, at Ballymadder and Bannow in 
Wexford; Clonea, near Dungarvan, in Waterford. 

C. sepium (Linn.)—The narrow-leaved, pink-flowered variety occurs at 
Courtown. ' 

C. soldanella (Linn.)—Abundant at Courtown, Rosslare, Carnsore, and 
all along the south coast of Wexford. 

Cynoglossum officinale (Linn.)—Ballymoney, Cahore, Rosslare, Carn- 
sore, and Churchtown, on the Wexford coast. 

[Anchusa officinalis (Linn.)—Naturalized in sandy wastes, Rosslare 
Point, Co. Wexford. ] é 

Lycopsis arvensis (Linn.)—Scarce along the coast. Raven Point, Ross- 
lare, and ‘‘ Bar of the Lough” in Wexford. 

Echium vulgare (Linn.)—Killurin and Rosslare in Wexford; near 
Youghal, on the Waterford coast. 

Lithospermum officinale (Linn.)—Shore, north of Courtown, where it 
was previously noticed by A. G. More. 


140 Scientific Proceedings, Royal Dublin Society. 


Myosotis collina (Hoffon.)\—-Sand-hills north of Courtown, and in 
several places between that and Arklow Head. 

Solanum nigrum (Linn.)—Rosslare, and “‘ Bar of the Lough,” near 
Bannow, in Wexford. 

Hyoscyamus niger (Linn.)—Rosslare ; ‘‘ Bar of the Lough,” Bannow, 
and Sandeel Bay, near Hook Head in Wexford. 

[Lycium barbarum (Linn.)—Established at Rosslare Point, Co. Wex- 
ford. | 

t Orobanche minor (Linn.)\—On Trifolium pratense, on the marl banks by 
the sea below Kilmuckridge in Wexford, and elsewhere in Wexford. 
(See ‘‘ Journal of Botany,’’ November, 1881). 

O. hedere (Duby.)—Strabally Cove, Waterford, plentiful. It has been 
previously recorded from here by Mr. T. Chandler. 

Linaria elatine (Mill.)—On the shore at the Greater Saltee Island. 

Lycopus europeus (Linn.)—Plentiful’ at Lady’s Island Lake in Wex- 
ford; near Ballyvoyle Head; and at Clonea in Waterford. 

Salvia verbenaca (Linn.)—A little north of Greenore, and at Carnsore 
and Duncannon in Wexford; Ardmore, in Waterford. 

Origanum vulgare (Linn.)—About Fethard, Co. Wexford. 

Calamintha officinalis (Mcench.)—Shore of Youghal Harbour, opposite 
Youghal, in Waterford. 

Lamium incisum (Willd.)—Near Churchtown, at Carnsore Point in 
Wexford. 

L. amplexicaule (Linn.)—Saltee Island in Wexford. 

Stachys arvensis (Linn.)—Tinnyberna, Raven Point, Greenore, Saltee 

Island, and near Fethard in Wexford. 

Ballota nigra (Linn.)—Rosslare Point, and Rosslare, Co. Wex- 
ford. a 

Utricularia vulgaris (Linn.)—Marsh at Clonea, near Dungarvan, Co. 
Waterford. 

Glaux maritima (Linn.)—Frequent. A curious growth, which seems 
to bear no flowers, and few leaves, occurs in the brackish lake at 
Lady’s Island. The branches are stout and numerous. 

Samolus valerandi (Linn. )—Frequent. 

Statice occidentalis (Lloyd).—Baginbun Head and Hook Head, in 
Wexford; cliffs west of Tramore, in Waterford. 

Armeria maritima (Willd.)— 

Plantago coronopus (Linn.)— | Common. 

P. maritima (Linn.)— 

Sueda maritima (Dum.)— 

Salsola kali (Linn. )— 


Frequent. 


Hartr—Hora of the Wexford and Waterford Coasts. 141 


Chenopodium rubrum (Linn.)—Raven Point, Rosslare, Saltee Island, 
and ‘‘ Bar of the Lough,” in Wexford. 

C. bonus-henricus (Linn.)—Fethard, Co. Wexford. 

Beta maritima (Linn.)—St. Margaret’s and Saltee Island, Wexford ; 
frequent on the steep Waterford coast. 

Salicornia herbacea Linn.)—Common. 

Atriplex littoralis (Linn.)—Raven Point, Tacumshin, Kilmore, and 
Hook Head, in Wexford. 

A. angustifolia (Sim.)—Frequent. 

A. hastata (Linn.), var. deltoidea— 

A. babingtonii (Woods).— 

Obione portulacoides (Moq.)—Sparingly on an insulated rock, a little 
north of Cahore Point, Co. Wexford. . 

Rumex maritimus (Linn.)—Plentiful at Lady’s Island Lake, Wexford. 

R. hydrolapathum (Huds.)—Curracloa, Lady’s Island Lake, and Bally- 
madder, on the Wextord ‘coast ; Clonea, near Dungarvan, Water- 
ford. 

Polyganum rati (Bab.)—Greenore and Sandeel Bay to St. Patrick’s 
Bay on the west side of Hook Head, in Wexford; Clonea, and at 

. the Kinnegar, Dungarvan and Bunmahon, Waterford. 

P. aviculare (Linn.), var. littoralis—In several places on the southern 
Wexford coast. 

Euphorbia paralias (inn.)—Frequent all round the sandy coast of 
Wexford ; between Ardmore and Youghal, in Waterford. 

[E. peplis (Linn.)—See previous part of this Report.] 

E.. portlandica (Linn.)—Cahore Point,. Raven Point, and Crossfarnoge, 
in Wexford. Much scarcer than the last. 

Ei. exigua (Linn.)—Sandeel Bay, on the west side of Hook Head, 
Wexford. ‘- 

Salia repens (Linn.)—A very prominent sand-hill pees in many 
places. 

Quercus robur (Linn.)—Common along fhe steep Waterford coast. 

Orchis pyramidalis (Linn.)—Sand-hills at Courtown and Curracloa, in 
Wexford. 

Habenaria viridis (R. Br.)—Raven Point, in Wexford; and Bally- 

» dowane Bay, in Waterford. 

Epipactis palustris (Linn.)—Cahore Point to Raven Point, amongst 
the sand-hills in many places, Co. Wexford. 

Asparagus officinalis (Linn.)—“ Bar of the Lough,” about half way . 
between Crossfarnoge and Bannow, and at Bannow Island, Wex- 
ford. 


Common. 


142 Scientific Proceedings, Royal Dublin Society. 


Juncus maritinus (Sm.)—Frequent. 

J. compressus (Jacq.)—Common. 

J. acutus (Linn.)—Along the whole east coast of Wexford where suit- 
able extent of sand-hills occur, and occurring also on the Water- 
ford coast at Tramore and Dungarvan, but not on the south coast 
of Wexford. This handsome rush extends north nearly as far as 
Wicklow Head. It is more abundant south of Cahore Point, in 
Wexford, than in its other localities. It also occurs, sparingly, in 
Cork. 

J. glaucus (Khrh.)—Frequent. 

Alisma ranunculoides (Linn.)— ; 

Triglochin maritimum (Linn.)— }) Clonea, Waterford. Common. 

Typha latifolia (Linn.)— 

Arum maculatum (Linn.)—Abundant in thickets on sand-hills, as at 
Courtown. . 
 Potamogeton pectinatus (Linn.)—Lady’s Island Lake and Crossfarnoge, 

_ Wexford; Clonea, in Waterford. Local. 

P. pusillus (Linn.)—Thriving in brackish water with the last species. 
Frequent. 

Ruppia maritima (Linn.), var. rostellata.—Raven Point, Wexford ; 
Clonea, Waterford. 

Zannichellia palustris (Linn.)—Lady’s Island Lake, Wexford ; Clonéa, 
Waterford. 

Zostera marina (Linn.)—In the estuaries, abundant. 

Scirpus maritimus (Linn.)—Frequent in brackish places; usually the 
first symptom of a river’s having been influenced by the tide. 

S. tabernemontant (Gm.)—Morris Castle, Lady’s Island Lake, in Wex- 
ford ; Clonea, in Waterford. 

S. savit (S. et M.)—Raven Point, Lady’s Island Lake; and Saltee 
Island, in Wexford. 

Carex arenaria (Linn.)—Abundant. 

C. vulpina (Linn.)—Frequent. 

C. paniculata (Linn.)—Clonea, Waterford. 

C. acuta (Linn.)—Ballymadder, in Wexford; Clonea, Waterford. 

C. pendula (Huds.)—Duffcarrig and Courtown, Wexford. 

C. eatensa (Good)—Rayen Point, Rosslare and Saltee Island, ‘in 
Wexford ; Waterford, in several places in the estuaries. 

C. distans (Linn.)—Frequent. 

C. riparia (Curt.)—Near Kilmichael Point; and near Morris Chats. 
on Wexford coast. 


Hart—Flora of the Wexford and Waterford Coasts. 148 


[Carex remota (Linn.); C. ovalis (Good); C. stricta (Good); C. hirta 
(Linn.), and other commoner inland sedges were also observed. | 

Phleum arenarium (Linn.)—Cahore Point, Raven Point, and Rosslare, 
in Wexford. 

Psamma arenaria (R. et §.)—Common. 

Glyceria aquatica (Sm.)—Tinnyberna, and abundant near Morris 
Castle, in Wexford; at Clonea marsh, in Waterford. 

Sclerochloa maritima (Lindl.)—Common. 

S. rigida (Link.)—Not unfrequent. 

S. loliacea (Woods)—Wexford coast, in several places. 

Festuca uniglumis (Sol.)—Courtown, Cahore, Curracloa and Raven 
Point, in Wexford. 

F, arundinacea (Schreb.)—Frequent. 

Triticum junceum (Linn. )—Frequent. 

‘Elymus arenarius (Linn.)—Raven Point, Rosslare Point, Rosslare ; 
and at Greenore Point, on the east coast of Wexford. Probably 
not native. 

Equisetum maaimun (Lam.)—Frequent. 

E. hyemale (var. moorei).—Along the coast of Wexford to Raven 
Point, frequent; not met with south of Wexford Harbour, 
Asplenium marinum (Linn.)—Saltee Islands and Hook Head, Wex- 

ford ; frequent on the more suitable Waterford coast. 
Osmunda regalis (Linn.)—Ballydowane Bay and Helvick Head, in 
Waterford. ) 


[ List or Piants 


144 Scientific Proceedings, Royal Dublin Society. 


LIST OF PLANTS OBSERVED ON THE SALTER 
ISLANDS. 


[The letter (B) after the name of a plant implies that it was only observed on the 
smaller island; and when a species of interest occurred on both islands, this is denoted 
by the letters (A) and (B) similarly placed.] 


Ranunculus hederaceus. Lathyrus pratensis. 
R. flammula. Potentilla tormentilla. 
R. repens. P. anserina. 
R. acris. Rubus fruticosus (villicau- 
}Fumaria officinalis. lis ?). 
Cardamine hirsuta. Lythrum salicaria. 
Cochlearia officinalis. Peplis portula. 
+Raphanus raphanistrum. Lepigonum marinum (B). 
Viola sylvatica. L. rupicola. 
TY. tricolor. }Spergula arvensis. 
Polygala vulgaris. Sedum anglicum. 
Silene maritima. Cotyledon umbilicus. 
Sagina procumbens. Hydrocotyle vulgaris. 
S. maritima. . (nanthe crocata (B). 
Cerastium glomeratum. Crithmum maritimum (A), 
C. triviale. (B). 
Stellaria media. Heracleum sphondylium. 
Hypericum elodes. Conium maculatum. 
{Geranium dissectum. Hedera helix (?). 
G. molle. Lonicera periclymenum. 
Krodium maritimum (A), (B). *Sherardia arvensis. 
Radiola millegrana. +Galium aparine. 
*Ulex europues. G. palustre. 
Medicago lupulina (B). {Petasites vulgaris (B). 
Trifolium pratense. Tussilago farfara. 
T. repens. Aster tripolium. 
T. minus. Bellis perennis. 
Lotus corniculatus. Inula crithmoides. 
Li. major. Pulicaria dysenterica. 
Vicia cracca. {Anthemis cotula. 


V. sepium. Matricaria inodora. 


Hartr—Flora of the Wexford and Waterford Ooasts. 145 


tChrysanthemum segetum. Armeria maritima. 
Guaphalium uligimosum. Plantago coronopus. 
Senecio jacobeea. P. maritima. 
S. vulgaris. P. lanceolata. 
Centaurea nigra. +P. major. 
Arctium minus. {Chenopodium album. 
Carduus palustris. C. rubrum. 
C. arvensis. Beta maritima. 
©. pyenocephalus. Atriplex babingtonii. 
Thrincia hirta (B). A. hastata. 
Hypocheris radicata. Rumex obtusifolius. 
Apargia autumnalis. R. crispus. 
Leontodon taraxacum. R. acetosa. 
Sonchus oleraceus. R. acetosella. 
+S. arvensis. +Polygonum aviculare (B). 
Hieracium pilosella. P. hydropiper. 
Jasione montana. Kuphorbia helioscopia. 
Calluna vulgaris. E.. paralias. 
Erica cinerea. Callitriche platycarpa. 
Hrythrea pulchella. Urtica dioica. 
K. centaurium. U. urens. 
+Symphytum officinale. Scilla nutans. 
Myosotis arvensis. Juncus conglomeratus. 
Linaria elatine. J. supinus. 
HKuphrasia odontites. J. bufonius. 
i. officinalis. J. compressus (B). 
Pedicularis sylvatica. Luzula multiflora. 
Veronica chamedrys. Lemna minor. 
{V. agrestis. Scirpus savii. 
VY. serpyllifolia. Carex arenaria (B). 
Nepeta glechoma. C. stellulata. 
Prunella vulgaris. We Ge @veiligs 
{Lamium amplexicaule. C. extensa (B). 
L. purpureum. C. binervis. 
{Stachys arvensis. Anthoxanthum odoratum. 
§. palustris. Aira caryophyllea (B). 
Teucrium scorodonia. Agrostis alba. 
Anagallis arvensis. Alopecurus geniculatus. 
A. tenella. Holcus lanatus. 


Samolus valerandi (B). | Arrhenatherum avenaceum. 


146 Scientific Proceedings, Royal Dublin Society. 


Triticum repens (B). Lastrea filix-mas. 
Poa annua. L. filix-foemina. 
Sclerochloa maritima (B). L. dilatata. 

Festuca ovina. Blechnum boreale. 
Lolium perenne. | Pteris aquilina. 
Equisetum maximum (B). Asplenium marinum. 
‘Polypodium vulgare. 


This list contains 153 species ; probably more occur on the is- 
lands, which would require another and a longer visit in spring to 
make an exhaustive catalogue of their plants. There are, at any 
rate, four or five plants whose names do not appear in my note- 
book that it is hard to believe are absent. The chief interest in this 
list, in addition to the occurrence of some rarities mentioned in the 
body of this report, is the presence of a good proportion of plants 
belonging to Watson’s Atlantic type. Of these, we have Hyperi- 
cum elodes, Erodium maritimum, Sedum anglicum, Cotyledon umbili- 
cus, Crithmum maritimum, Inula erithmoides, Euphorbia paralas, and. 
Scirpus savii. If we look to the flora of Tory Island, as reported 
upon in the “ Journal of Botany,” 1879, by my friend Mr. Barring- 
. ton, we shall find but two members of this group. ‘This island lies at 
' the opposite corner, on the north-west of Ireland, and is more than 
double the area of those under consideration. Its flora is scantier 
by about ten species, and of much less interest; but the comparison 
well shows the failure of this type as we travel northwards, in 
spite of the more western and Atlantic situation of the larger 
island. 


Norlen 


XVI.—ON THE POSSIBILITY OF PROLONGING THE TONES 
OF A PIANOFORTE SO AS TO PRODUCE AN IN- 
STRUMENT WITH THE QUALITY OF TONE OF THE 
PIANO, AND THE CONTINUITY OF TONE OF THE 
ORGAN, By G. JOHNSTONE STONEY, M.A., D.Se., 
F.R.S. 

[Read, June 18, 1883.] 


Ir is a peculiarity of the piano, the harp, the guitar, and other 

instruments, of which the strings are either struck or plucked, that 

a note even when held down dwindles in intensity ; so that on such 

instruments no musical effect can be produced which requires each 

tone to be maintained throughout its continuance as loud as when 

first struck, as upon the organ, the violin, and most wind instru-. 
ments. . 

Composers of piano music sometimes imitate this effect in a 
way which is necessarily imperfect and of limited application, by 
occasionally introducing into their compositions repetitions of a 
note or chord at very short intervals. But however rapidly the 
performer may execute such passages, the effect is at once felt by 
the ear to be very different from what such a passage would pro- 
duce upon an organ—the repetitions are heard as repetitions ; the 
note or chord is not really continuous. 

This is due to two causes. Between the successive impacts of 
the hammer upon the string the intensity of the sound decreases ; 
and, moreover, at each impact there is a new departure, impressing 
the ear as a breach of continuity. In fact, the intervals between 
the strokes in general consist of a broken number of vibrations, 
that is, of an integer number of vibrations, with the addition of 
some irregular fractional part of a vibration, so that the vibrations 
of any one of the intervals do not in general form the same series 
as those of the intervals that precede and follow it. 

- This last source of discontinuity will be removed if we have 
any way of securing that the successive strokes of the hammer 
shall fall upon the string when it is in the same phase of its vibra- 


148 | Scientific Proceedings, Royal Dublin Society. 


tion; and it would only remain to ‘ascertain by experiment how 
rapidly such blows would need to be delivered to maintain - ‘a sui- 
ficient uniform intensity. 

I have for some years had it in contemplation to make the 
necessary apparatus for applying this method to the piano, but 
other occupations have so long prevented me from doing so, that 
I now mention the subject in the hope that some other person with 
better opportunities and more leisure will carry out the investiga- 
tion. 

A perfectly continuous tone would, of course, be produced if 
the hammer could be made to strike the string every vibration. 
But it does not seem at all likely that it would be necessary to 
strike it every vibration—probably not more than once every 
twenty-five or thirty vibrations, provided that the blow, when it does 
come, reaches a string which is in precisely the proper phase of its 
motion. Hence, the condition to be fulfilled is, that the intervals 
between the blows shall be capable of being tuned into accord, if 
- I may use the phrase, with some multiple of the period of vibra- |’ 
tion of the string. A mechanism constructed so as to deliver an 
impact at each swing of a short pendulum, of a balance-wheel, or 
of a very large tuning-fork, might be adjusted to the string, or the 
string tuned to it, in the way required; and an apparatus regulated 
in this way, if applied to a piano with good repeating action, might 
be made to impinge directly on one of the ivory keys, which would 
probably be the easiest way of making a sufficient preliminary 
experiment, without a specially-constructed piano. A weight or 
spring acting on very simple clock-work would suffice as the motive 
force ; or, perhaps, electricity could be conveniently employed ; but 
I think it would be found easier to render the arrangement suf- 
ficiently noiseless with a purely mechanical apparatus, avoiding 
electricity. Should the ticking or other noise of the apparatus 
for the preliminary experiment be troublesome, the apparatus 
will need to be boxed in or the noisy parts placed in an adjoining 
room. 

If the anticipated result can be attained, an entirely new range 
of musical effects will be at our disposal, for we shall have within 
our reach an instrument with the quality of tone of the piano—one 
of the most pleasing qualities of tone among musical instruments— 
and on which much of the best organ music can be executed. 


f ee 


XVII.—NOTE ON THE EFFECT OF FLEXURE ON THE PER- 
FORMANCE OF TELESCOPIC OBJECTIVES. By 
HOWARD GRUBB, F.R.S. 


[ Read, June 18, 1883. | 


Durine my work on the 27-inch objective for the Vienna Refrac- 
tor, I was led to study more closely than heretofore the effect of 
flexure on one or both lenses of a large objective, and as the results 
which I arrived at, both in actual practice and on consideration of 
the subject theoretically, were very different to what might at first 
sight be considered natural, I thought it might be interesting to 
place the matter on record. 

Tiet me first, however, explain that this flexure is of most 
serious consequence in the preparation of object-glasses of large 
size. It may be thought by those not conversant with the sub- 
ject that any flexure that could occur in a dise of glass, say of 
twenty-four inches diameter and from one to two inches thick, 
from, or due to, its own weight, must be so infinitesimal as might 
be fairly neglected in the general results; but this is not so. I 
can easily demonstrate to ygqu that such flexure is a mechanically 
measurable quantity, and one-tenth of the smallest quantity thus 
measurable would be quite sufficient to make all the difference 
between a good objective and a bad one. 

This last assertion I am not in a position to demonstrate, but 
anyone who has attempted to make an objective or a speculum for 
a reflecting telescope will bear me out in what I say. 

The flexure that I propose to consider in this communication is 
that due to the weight of the disc of glass itself, which alters the 
figure or shape of the dise as it les in its cell, supported round the 
edge only on three fixed points, or on three fixed and any number 
of adjustable points, but in all cases round the edge only. So long 
as the glass is on its polishing machine undergoing the various 
processes of grinding, polishing, figuring, &c., it can be supported 
on a perfectly equable support of some kind, such as reflectors are 
laid on both for manipulation and for actual working; but it is 


SCIEN. PROC. R.D.S. VOL. IV. PT. III. O 


150 Scientific Proceedings, Royal Dublin Society. 


evident that in the case of a refractor no supports are admissible 
once it is placed in its tube, except on a narrow band round the 
extreme circumference. It is therefore evident that the most 
perfect support we can give can only go so far as to support it 
equally round the whole circumference. 

The whole lens, therefore, alters its shape in accordance with 
the altitude of the object under examination : the higher the alti- 
tude, in the case of the crown lens,\ the less convex the first surface 
becomes and the more convex the second. ‘This, in a moderately 
thin lens, becomes a measurable quantity ; but provided the support 
be perfectly equable round the whole circumference, the effect on 
the image is imperceptible: it is practically the same, in fact, as if 
the first surface were increased in radius by an almost infinitesimal 
amount, and the second diminished by the same, the gross result 
being almost exactly the same. In general, too, it may be assumed 
that any flexure which does not cause one or other of the surfaces 
to cease to be a surface of revolution is of no consequence, unless, 
indeed, it amounts to such a quantity as to cause polarization. 

When, however, a large thin lens is supported on three fixed 
points only round its circumference, or that, from any cause, the 
support is not equable round the edges, there must be, and is, a 
considerable variation from a surface of revolution, and as this 
flexure will naturally increase largely as the thickness of the lens 
diminishes, I have been much surprised to find the effect on the 
image due to this flexure no more troublesome in thin lenses than 
in thick, and this it is that has led me to investigate the matter. 

The general result of my investigations is rather remarkable, 
and goes to show that in the more usual construction of telescopic 
objectives, and suppposing all the surfaces to be truly surfaces of 
revolution as they came from the polishing machine, the thickness 
of the lenses (within moderate limits) is of very little consequence, 
and for the following reasons :— 

The flexure of the glass we may probably assume to follow the 
ordinary law, as being inversely proportional to the square of the 
thickness for any given weight or load; but as the weight of the 
glass itself diminishes directly as the thickness, the flexure due to 
its own weight will be just inversely as the thickness (not as square 
of the thickness). But now as to the effect on the image. If the 
lens were infinitely thin, the effect would be n7/, for wherever 


Grussp—Flecure on Performance of Telescopic Objectives. 151 


one surface got convex the other would get concave by an equal 
amount; and the only reason why flexure in a lens does distort the 
image is, that after the rays are disturbed from their true path, by 
the alteration of curvature of first surface, they have to travel some . 
distance (7. e. the thickness of the lens) before they are corrected 
by the other; and the effect, therefore, of any given flexure on the 
image varies directly as the thickness (almost exactly for moderate 
thickness). 

As, therefore, the flexure varies inversely as the thickness, and 
the effect of that flexure varies directly as the thickness, it follows 
that the effect on the image, from flexure of the discs due to their 
own weight, is about equal, no matter what the thickness is. 

This curious result explains to me how it is that we just as often 
find evidence of flexure in thick as in thin lenses, and other for- 
merly puzzling matters. 

The above result is only strictly true when the bending or 
refraction is equal on both surfaces, which is approximately the case 
with the crown lens of the ordinary form of telescopic objectives, 
but not with the flint ; from which it follows that it is more neces- 
sary to have thickness in the flint than in the crown. 

It is well known among opticians that this is practically the 
case, but the reason generally assigned is, either that the form of 
the flint is not so well calculated to resist flexure, or that the spe- 
cific gravity being higher, the load is really greater. 

It would, however, appear now that there are other reasons. 

Tt also follows from the above that objectives constructed on the 
“‘ Gauss ’’ system, in which the refraction is very different on the 
different surfaces, will suffer more from any flexure due to their 
own weight than those constructed on the more ordinary system. 


f te. j 


_ XVIII. —ON SOME CURIOUS NUMERICAL RELATIONS OF 
THE MUSICAL SCALE. By JOCELYN H. THOMSON, 


Lieutenant, Royan ARTILLERY. 
[Read, June 18, 1883. ] 


Tuer accompanying Table represents an octave divided into forty- 
seven parts, in such a manner as to give twenty-four complete 
major keys with perfect intervals, namely, those whose tonics are 
marked with an asterisk. All these keys, except those of Abb., 
Ch,, and Ebb, have their minor seales also complete. 

Column I. of the Table gives the names of the notes, the figure 
below each serving to distinguish it when there is more than one 
of the same name. Column II. gives the different keys to which 
each note belongs. Column III. gives the fractions representing 
the ratio of the number of vibrations of the note to that of C,. 
Column IV. gives the same ratio expressed as a logarithm. From 
the principle of logarithms it is evident that this column gives the 
numerical value of the interval from ©;. Column VI. gives the 
logarithms, and, consequently, the numerical values of the inter- 
vals in a scale of equal temperament; 7. ¢. a scale in which the 
octave is divided into twelve equal parts, or semitones. Most 
modern keyed instruments are tuned to equal temperament, which 
system offers so many advantages, as to counterbalance the disad- 
vantage that no interval is absolutely perfect. 

Since Column VI. gives the numerical value of the interval in 
a scale of equal temperament, and Column IV. that of the true 
interval, the difference between these two will give a measure of 
the discord between the notes on the two scales. This difference 
is given in Column VII. Now, on an inspection of this column, 
the following points will be noticed :—First, that the numbers on 
either side of the centre of the scale are equal, but of opposite sign. 
This is merely due to the fact that in both scales each interval from 
the lower C has a corresponding interval from the upper; or, in 
other words, both scales are symmetrical. Next, it will be noticed 


THomson—On Numerical Relations of the Musical Scale. 158 


that the discord is least in the case of the sub-dominant and domi- 
nant, which are the principal notes after the tonic in any scale. 
The third point to be noticed is, that all the numbers in this column 
are approximate multiples of one constant: (a) = °0004904 or 
‘009587 of a tone (2).1. This is shown in column VITI. Return- — 
ing to Column IV., it will be noticed that the last three figures of 
the logarithms follow a system. This points to the fact that there 
is a relation between the distances apart of successive notes. In 
every group of four the two outer intervals are equal to lla, and 
the inner one to 10a. We will call the former P, and the latter 
Q. The interval P is one that constantly recurs in the mathema- 
tical treatment of the musical scale. It is, in fact, the major 
Comma (84), and is the difference between the Major Tone (2) and 
the Minor (1°). The interval Q is called the Minor Comma (3$$8). 
It is the difference between the Enharmonic Diesis (13%) and the 
Major Comma, the Enharmonic Diesis, being the difference between 
the Major Semitone (1%) and the Minor (24). The intervals be- 
tween successive groups of four involve a third quantity (43823), 
which may be called the Diminished Comma. This interval is the 
difference between three minor semitones and a major tone. The 
three constants P, Q, R give a convenient measure of the intervals 
from ©, of all the notes in the above scale; and, moreover, any 
musical interval which can be formed from the diatonic scale may 


be expressed in simple terms of P, Q, R 


NOTE ADDED IN THE PRESS. 


Since the fractions representing musical intervals must be multiplied 
together in order to obtain the fraction representing the sum of those ' 
intervals, therefore the quantity 34P + 19Q + 12# (the octave) is really 


SINE 2048\19 15625\" : . 
equivalent to (a ) x (sons 0) x (iossa) . This fraction when mul- 


1 This relation Fopadse on the coincidence that 29 is ae eave ton lOLzEx 38; for 
if z 2173 — 102 x 384, 
then 173 log 2=12+ 84 log 3 
4 log 2449 log 2+ 84 log 2+ 24 log 2 +12 log 2=84 log 3 + 12, 
wiz log 2+ #3 log 2+ 7 log 2 + log 4+ log 2=7 log 3+1, 
5 log 2—1+log 2+ log 4=7 (log 3 — log 2 — 7% log 2), 
vs log 2—log 2}=—-7 (x log le =); 
SCIEN. PROC, R. D.S. VOL. IV. PT. III. le 


154 Scientific Proceedings, Royal Dublin Society. 


tiplied out has 179 digits in the numerator; and yet, when reduced to 
its lowest terms, it is exactly equal to 2. Consequently, it accurately 
represents the interval of the octave. 


which proves that the differences for the dominant and the mediant are commensurable. 
But the diatonic scale is made up of combinations of the major fifth and major third ; 
consequently, if the dominant and mediant have differences which are multiples of a 
constant, then the other degrees of the scale will have the same property. 

Again, if the relation holds good for one diatonic scale, it will also hold good for any 
others that are built up on it ; for the difference of any degree in a scale built on to the 
primary scale must be equal to the difference due to that degree plus the difference 
belonging to the tonic on which the scale is formed. For example Fog is the super- 
tonic of Ez. Now the difference for the supertonic is - 2a, and the difference for Ey 
is-+ 7a. Consequently the difference for Fog is+ 5a. N.B.—The equality of the 
above last equation is not exact, the left side being 7 (000490474126), and the right 

7 (000490428252). 


(CAL SCA] 


= 1 6 


“H THE NOTE BELONGS. 


ly 1M Ge, Aib, Aa, Bib 


Ay bp» Bi bb, Azbb, 0 


se 
of, 


1 b» C2 bs 


b, Gi, 


‘ 
ia 


; 2) 
ay : 


NUMERICAL RELATIONS OF THE 


| 


MUSICAL’ SCALE. 


Ts Il. II. IV. v. vi. vil. VIII. I. qr. ae, 7 = ae ae we 
li Differe Differ- Nore. : : 
Note Keys TO WHICH THE NOTE BELONGS. INTERVAL FROM C. Sen apa enna OTE Keys TO WHICH THE NOTE BELONGs. INTERVAL FROM C, Interval in Difference Differ- 
Fie ; ae 5 equal tems VI. and IV. at = = Sole of ee ence in 
Hany Logarithm. | In terms of £, Q,R. | Pp : ew Logarithm. | In terms of P,Q, R. mene oe : of). 
: -0000000 
*0, Ch, 4 | -0000000 | 0 7 Gaey e o C1, Dib, Bap, Hi, Fi, Ge, Arp, Ar, Bib, | 4 | -3010300 | 347+ 19Q + 122) f 0000000 0 
; 1 
81 | -00: J | -0000000 |4 —-0053950 = lla C G Bis Ree 
on Bob, $0 0053950 | P : | 8 1 BI | +2956350 | 33P + 19Q+12R $) -3010300 |< + -0053950 + lla 
128] « Ss = B 125 
Dbb Fab, Azbb, 433] 0103000; P+ @ «J Ls20108000 ie ¢ Og, “S4~ | -2907301 | 33P + 18Q4 12k +-0103000 + 2la 
: 5 = > a * e 48 
“Ot Di, Ei, Fig, Ar, 25 | -0177288 | 2P+ Q+ (+ 0073570 + 1ba Cab Exh, F2b, Gob, Arb," Bibb, Azbb, . 25 | +2833012 | 32P+18Q+4112 (—-0073570 Sie 
G3 5% jae 3 : * 
Cot Bo, Fed, 135 | -0231238 | aP+ Q+ R + 0019620 + 4a Cib Gib, Erbb, 735 | -2779062 | 31P+18Q+11R ~ 0019620 ia 
“0250858 
; 2759449 
16 : G =a ee 4 ‘ 
*Dib . Fob, Fi, Arb, Bib, Bibb, Gib, Crp, Erbh,| as | 0280287 | 3P+ 2Q@+ FR 0029429 6a *B, C1, Ei, Ge, Ai, Fog, 43 | -2730013 | 31P+17@4 112 + 0029429 PNG 
Qn | . ; 2a a Pat 
Dab Gh, By CHD, 27 | 9334938 | 4P.4 29+ Rk) | — 0083380 17a Bi Di, Fig, Gi, . 27 | -2676062 | 30P+17@+11R] 4. 0083380 Pere 
10 r K > 9 *Bo " ra ¢ 
Di Gi, Fi, Fig, Ai, Bib, “g- | 0457575 | bP+ 3Q+ 2k (+ 0044142 + 9a Bzb Exp, Gab, Ge, Arb, Cob, 2 | -9559725 | 29P+16Q + 10R ~ 0044142 50% 
9 “Nk 2 d € 
D2 Ci, Exh, Ga, Bob, Be, Fog, s 0511525 | 6P+ 3Q+ 2K — 0009808 — 2a *Bib Dip, Di, Fi, Gib, Gi, 16 | -9498775 | 28P+16Q+ 102 4 0009808 + 2a 
: . sa : -0501717 Z : ; +2508583 
Ei bb Bibb, Gib, Crp, 335 | 0560575 | GP+ 4Q+ 2k — 0058858 ~ La Aug Be, Fog, 2251 9449795 | 28P+15Q+10R 4 0058858 4 12a 
Exbb Gob, Cab, Arbb, 144) -0614525 | 7P+ 4@4+ oR) (— 10112808 — 230 Ag Cif, Fig, 125° | 2395775 | 27P + 15Q+10RJ -0112808 93 
+ + 28a 
125 a s & ca ¢ ‘ 
Dig Vg, Tow | 0634862 | 7P+ 4Q+ 3F) (+ °0117718 + 24a Bebb Gz, Abb, 216 | .9375438 | 27P+15Q+9R ) (- 0117713 — 24a 
Daft Of, Ei, Be, Fig, 75 | 0688813 | 8P+ 4Q+ 3k + 0063762 + 18a *Bibb Dib, Feb, Gib, Er bh, 128 | -2321487 | 26P+16Q+9R ~ 0063762 = ile 
“0752575 : “2957726 
Eib Bib, Gib, Gi, Crh, 32 | -0737862 | 8P+ 5Q+ 3R 40014713 + 8a Ay G2, Bob, Fog, 27 | -9272438 | 26P + 14Q+ 92 —~ 0014713 = % 
*Toh C1, Dib, Fap, Gab, Ge, Arb, Bab, Cob, . | & | 0791813 | 9P+ 5Q+ 3K) — 0039238 — 8a *AY C1, Di, Ei, Fi, Fig, Bip, Gi, 3 | -9218487 | 25P+ 14Q+ 92 ( + 0039238 + 8a 
Ey Gi, 40,2 | 0915150 | 10P+ 6Q+ 42 + *0088283 + 18a Ab Gap, SI | -2095161 | 24P + 13Q+ 8h { — 0088283 — 18a 
"Ee Ci, Ong, Diy Fy, Ga, Aa, Bay 5 | .0969100 | 11P+ 6Q+ 42 + 10034333 + Ta *Ab C1, Dib, Exh, Feb, Fi, Cob, Bibb. & | -2041200 | 23P + 13Q+ 82 — :0084833 °| — 7a 
: 1003433 2006867 
Pip. Gib, 212 | -1018150 |11P+ 7Q+ 4k ; —:0014717 — 8a Gof Fog, 495) -1992151 | 283P + 12Q+8R + 0014717 + Ba 
I 
“Fab Dips Arby Czby Bibb, Azbb» Exbb, 32 | -1072099 | 12P+ .7Q + 425 (— -0068666 = 14a = Gig Cig, Ei, Fig, Ai, Bo. 25 | -1938201 | 22P + 12Q+ 82 4. :0068666 
Hig Qt Fit, . P 125 | -1146388 |183P+ 7Q+ 5R +-0107903. |\ + 22a *Aobb Fab, Cab, 192) -1863912 | 21P4+12Q+7R y — +0107903 
06° : : { 
Ef | Tg. G75) -1200338 | WP + 7Q+ 52 | + 0058058 | + lla Aibb | Cubs Exbb, 1809962 | 20P + 12Q+ 7% \ = 0053958 
, ee ee 1254291 E ‘17 46008 
Fi Ci, Dip, Di, Ab, Ar, Bip, Gap, -  .) 4+ | -1249887 | 14P+ 8Q+ 5K + 0004904 - +a *G2 C1, Exp, Ei, Fi, Arb, Bob, Ba, ‘1760913 | 20P+11Q+7R — 0004904 —4 | 
c. : : 3 a | 


8Q+ 5k) 


(= "0049047 


(+ 0078475 


Di, Bi Dy 


1706962 


19P+11Q+7R 


zt es Ls 


Ve 

4 

0 
A 


=o 


XIX.—NOTE ON THE AMYGDALOIDAL: LIMESTONE OF 
DOWNHILL, CO. DERRY. By PROFESSOR J. P.- 
O'REILLY, M.R.LA. 


[Read, May 21, 1883.] 


Some months ago I received from Professor Hull a set of speci- 
- mens forwarded to him by Mr. Hgan, of the Geological Survey. 
He described them as filling cavities in sheets of basalt at Down- 
hill, county Derry, and added, “It seems to be the curious mineral 
mentioned by Portlock (p. 215 of his Report) as occurring in that 
locality.”” Mr. Egan further mentions, that a similar mineral is 
to be found at Ballymoney, Co. Antrim, associated with calcedony, 
and near Limavady, Co. Derry, where, in common with a hard, 
flinty breccia (such as occurs between the chalk and the basalt in 
various places along the great basalt escarpment), it appears to 
have its origin in masses of chalk and flint caught up in the 
basalt. 
Portlock thus describes the mineral :—“ A curious mineral 
oceurs in soft amygdaloid at Downhill. It is oolitic in structure, 
consisting of spheroids cemented together by pure white carbonate 
of lime or by green earth. In the latter case it has much the 
appearance of pudding-stone. ‘The spheroids are yellow, whitish, 
or greenish, and appear to be a mixture of the hydrocarbonates of 
lime and magnesia. ‘The small cavities are lined with drusy 
erystals of pure white carbonate of lime: where exposed, the 
eement, yielding first, assumes a mammillated appearance.’’! 

He further adds, that the ‘greenish aragonite of Ballintoy and 
the brownish aragonite of Downhill both contain a sensible amount 
of strontian. 

The samples forwarded by Mr. neato show the more usual 
forms of occurrence of the mineral and the rarer forms. ‘There is 
also one showing “obscurely the manner in which the mineral is 
often associated with aragonite.”’ 


1 Geological Report on Londonderry, p. 215. 
SCIEN. PROC. R.D.S.—VOL. IV. PART IV. Q 


156 Scientific Proceedings, Royal Dublin Society. 


The greater number of the samples show an oolitic structure, 
such as is mentioned by Portlock, only that in none of them is the 
- cement of green earth, some of this mineral being, however, present 
on one or two of the specimens. 

It may be taken for granted that the samples forwarded are of 
the same nature as those alluded to by Portlock. The question is, 
Are they hydrocarbonates of lime and magnesia, as he presumes— 
that is to say, hydrodolomite, as suggested by Mr. Hgan ?P 

A fair sample of one of the specimens was analysed by Mr. 
Templeton, one of the students of the Royal College of Science, 
and the following are the results :— 


CEOue ee eee, eto 
MgO, . ; : : 5) ORE 
INIEO® We 1NSOS, a : Sig O87 
Insoluble matter, . : . 0°54 
CORT é : ..  . 48°64 
Moisture, : js : 2 Oca 

100:50 


A portion of this same sample gave a density of 2°722. Hydro- 
dolomite, according. to Dana, has a density of 2°495; therefore, . 
neither by analysis nor by density can this mineral be described 
as hydro-dolomite: both would make it simply carbonate of lime 
relatively pure. 

However, the examination of the hardness showed that the 
white oolites cut ordinary limespar; therefore they must have a 
hardness greater than 3. Aragonite crystals they do not cut, both 
minerals appearing to resist about equally. The hardness of the 
oolites may therefore be taken at 3°5. ‘The density, being merely 
that of pure calcite, would seem to argue against its being arago- 
nite; but Naumann gives for aragonite in the aggregated form, as 
lowest limit of density, 2°7. These oolites are, strictly speaking, 
ageregates, and the density of 2-722 is admissible for their beg 
aragonites. On the other hand, this density excludes the assump- 
tion of their being dolomites, the limits of density for which are 
2°8 to 2:95. 

In order, however, to test this point, samples were submitted 
to the action of acetic acid, which in all cases rapidly decomposed 


O’Rettty—WNote on the Amygdaloid Limestone of Downhill. 157 


the oolitic parts, but only partially, and in certain parts, in no ways, 
attacked the matrix of the oolites. 

This matrix has a distinct colour and crystalline structure, but 
so far I have been unable to separate it in sufficient quantity to 
get its density. However, it would seem from the foregoing 
considerations that this mineral is really constituted of oolitic 
aragonite in a matrix which presents to a greater or less extent 
the character of dolomite. 


XX.—ON AN APPARATUS FOR OBTAINING TELEGRAPHI- 
CALLY THE READINGS OF METEOROLOGICAL IN- 
STRUMENTS PLACED AT A DISTANCE FROM THE 
OBSERVER. (Plates III. and IV.) By J. JOLY. 


[Read, February 19, 1883. ] 


‘Tur contrivance described in this Paper is one which may be 
attached or adapted to the various thermometers, the barometer, 
rain-gauge, and to some others of the instruments installed, say, in 
a mountain station, enabling their readings to be taken from a 
conveniently-placed observatory. 

It is submitted that the arrangements are not of a costly 
nature, or more complicated mechanically than those daily in use 
in every telegraph office. The proposal for a distributor, as de- 
scribed in the latter part of the Paper, is advanced with more 
diffidence, as it has not yet been practically tested. 

A brief generalization of the method proposed will be of 
assistance in subsequently considering the details of the appa- 
ratus. 

To take the case of a thermometer: its stem is left open, a fine 
wire being arranged to move freely upwards or downwards within 
it. An electro-magnet forms part of the contrivance—which we 
will suppose is some miles distant from the observer. The 
electro-magnet is, however, in circuit with the home station, and 
matters are so arranged between it and the movable wire, that 
each time a current is sent from the home station to the electro- 
magnet the wire is advanced downwards by a certain amount. 
Say this advance is the ;};th of an inch. If fifty makes and 
breaks are effected in the home station, the wire in the instrument 
will have moved downwards by half an inch. Suppose, now, that 
a return circuit connects the mercury in the thermometer with the 
home station, so that, as soon as the descending wire meets the 
mercury where it stands in the tube of the thermometer, the cur- 
rent supplying the electro-magnet will be returned by the circuit, 
causing a galvanometer in the home station to deflect. The mo- 


Joty—On the Reading of Meteorological Instruments. 159 


ment of contact will, by this means, be known to the observer ; 
and if, further, the position of the movable wire, when started.on 
its downward course, was known to him, a record of the number of 
contacts will give him the reading of the thermometer or other 
instrument. 

In Plate III. a plan and sectional elevation of the necessary 
mechanical arrangements are given. 

The vertical shaft or spindle, s, shown in section in the plan, is 
pivoted at each extremity, so as to turn freely on its axes. It 
carries for a portion of its length a screw thread, which, as shown, 
has a pitch of ~>th of an inch. It also carries a small wheel, 
notched with triangular teeth, twenty in number. A still smaller 
wheel, w (elevation), gears with the cogged wheel, w’, so that, as 
will be readily understood from the figure, the spindle s, in 
turning on its axes, either moves or is moved by the weight, P, 
contained in the hollow pillar supporting the apparatus. 

A nut carrying a horizontal arm, f, bites on the screw. This 
arm is held from rotating with the screw by the vertical guides 9, 0. 
The rotation of the screw, therefore, imparts a vertical motion to 
the limb 7. The fine platinum wire, p (elevation), hangs loosely 
from the extremity of f; it is, in fact, retained from falling 
through an aperture provided for it by a small enlargement or 
stop. A thermometer, ¢, is so placed, that vertical motion im- 
parted to f raises or lowers this wire in its tube, which, to that end, 
is left open. | 

Two pairs of electro-magnets are shown in plan. One of these, 
e, é, serves to impart motion to the triangular-toothed wheel, and 
hence {to the screw, which it turns in such a direction as to lower 
the platinum wire into the tube of the thermometer. The other 
pair, ¢’,e’, serves to release the wheel from the control of the 
pallet, g, so that the descent of the weight P (raised at the same 
time that f was being urged downwards) may restore the arm f ~ 
and wire p to their highest positions. ‘The return wires from both 
electro-magnets are put to earth through a small resistance. An 
adjustable and insulated limb, for contact with the wire p when in 
its highest position, is shown at n (elevation). A single wire from 
the home station branches-to this and to the mercury in the ther- 
mometer. Two more wires are needed—one to e, e, another to ¢’, e’. 
A reading is effected as follows :— 


160 Scientific Proceedings, Royal Dublin Society. 


A rheotome at the home station puts the wire leading to e, e for 
a moment into circuit with a battery.'! If the platinum ‘wire p is 
in its highest position, as it should be, and hence in contact with 
n, the current will, during the first instant, return by the wire 
common to x and to the thermometer—/.e. by wire No. ur. This 
fact is known at the home station by the deflection of a galvano- 
meter in circuit with wire No. ut. The magnet e, e, however, im- 
mediately attracts up an armature attached. to the arm 7. This 
arm is hinged at one extremity; at the other it carries a smooth 
steel pallet, z. The pallet, on moving forward, engages with one 
of the triangular teeth, turning the wheel through such a distance 
that a second pallet, g, just gets over another of the teeth, and, on 

‘the current being turned off, and the first pallet being restored to - 
its neutral position by the agency of the spring 2, completes the ~ 
turning of the wheel through one tooth. One make and break, 
then, of the rheotome serves to turn the wheel and screw by 5th 
of a revolution (as there are twenty teeth provided). The screw, 
however, has a pitch of ~4th of an inch; hence a motion down- 
wards of ;1,th of an inch has been imparted to the wire p. The 
weight P has also been raised through a certain distance. A 
second make and break of the rheotome urges the wire downwards 
by another 51,th of an inch; and so on. Ultimately, when the 
wire reaches the mercury in the thermometer, a second deflection 
of the galvanometer on wire No. mt. in the home station takes place. 
The number of contacts made is read on the rheotome, and the 
height of the thermometer deduced. 

Contact is now made for a few seconds between wire No. II. 
and the battery. ° The effect on the instrument is, that by the 
motion of the arm 7 towards the electro-magnet ¢’, ¢’, the pallet x, 
moving backwards, lifts the second pallet, g, out of the wheel, and 
so liberates the wheel to the action of the weight P. The limb / 
and wire p are consequently run up to their highest positions, on 
attaining which a deflection of the galvanometer once more occurs, 
and the observer in the home station breaks contact. . 

The object of having the wire p hung loosely on the arm f, 
instead of having it firmly attached to it, is probably apparent. 


' Tf the instrument be very far removed from the home station, a relay to supply 
the necessary current to the electro-magnets will be required. 


Joty—On the Reading of Meteorological Instruments. 161 


In the latter case, if failure of proper contact between the wire 
and the mercury occurred, the observer might damage the ther- 
‘mometer by urging the wire below the surface of the mercury. 
As arranged, the wire, under such circumstances, would merely 
rest on the surface of the mercury, however far f was urged 
downwards. 

The weight P might perhaps with advantage be dispensed 
with in favour of a spring coiled in a drum fixed on w’. With 
the dimensions shown, this spring would be subject to five turns 
- during the complete descent of the wire. 

This arrangement, being of a purely mechanical type, admits 
of many variations. One form has been made for me by Mr. 
Yeates, in which the elevation of the wire is effected by rotating 
the toothed wheel in the opposite direction by the second electro- 
magnet. The contrivance for effecting this is due to Mr. Yeates. 
In this case the screw itself advances downwards or upwards, 
carrying the platinum wire attached to its extremity. The screw 
bites in a nut borne by the toothed wheel, but is held from turning 
with it, being slotted longitudinally, a fixed pin projecting into 
the slot. Such a form, although found to work very satisfactorily, 
has the great disadvantage of requiring as many makes and breaks 
of circuit to lift the wire out of the thermometer as to take the 
reading in the first instance. The quick return in the present 
arrangement does away with this objection.’ 

It will be noticed that three wires are needed to work the 
instrument—one to each magnet—that is, one to lower the movable 
wire, and one to raise it, a third being necessary to notify the 
position of the wire, whether in contact with the starting-point 
contact or with the mercury contact. Now, it will be obvious that 
this third wire might be common to any number of instruments 
centained in an observatory, and the second wire might be dis- 
pensed with by the addition to each instrument of an arrangement 


1 The instrument constructed for me reads to the z;th of a degree Fahrenheit. 
‘This delicacy is unnecessary, and has the disadvantage of making reading a slow and 
tedious operation. Its certainty of action is all that could be desired. In the form 
proposed aboye a delicacy of 4th of a degree Centigrade is intended, each degree 
causing a rise of about 5th of an inch in the mercury. 

A little glycerine is placed over the column of mercury in the thermometer, to 
exclude air bubbles. 


162 Scientific Proceedings, Royal Dublin Society. 


for automatically shunting the current from the electro-magnets 
e,e to the electro-magnets ¢’, e on contact being made with the 
mercury, or on. complete descent of the wire. In any case, as 
described, the number of wires making up the cable going to the 
observatory would not, for » instruments, exceed 2n + 1. 

Any number of instruments, however, may, I venture to think, 
be worked with perfect reliability and certainty by the use of three 
wires only. Plate IV. will show how this is accomplished, the only 
extra piece of apparatus needed being a disc,! carrying insulated 
contact pieces arranged round its circumference. ‘To these the 
wires, &c., of the different instruments are attached. Of the three 
needful wires, then, 1. serves to put one after the other of the con- 
tacts into circuit with the home station through wire u. By this 
second wire the readings are taken and the readjustment of the 
instruments effected. The arrangement by which the current 
through 1. puts the wire 11. in communication successively with 
the several contacts will be understood from the figure and from 
the foregoing description of a similar mechanical contrivance in 
the case of the thermometer. Wire ut. for indication of the 
- contacts, is taken from all the instruments to the galvanometer in 
the home station. 

One of the wires in the observatory is shown on the diagram as 
a “test wire.” When the movable hand arrives at the contact 
piece attached to this wire, the current on 1. returns through 11. 
to the home station. If, therefore, at any time a check on the 
position of the hand of the distributor in reference to the indica- 
tions of the commutator at the home station is desired, it is only 
necessary to work the commutator, 11. being put in connexion with 
the galvanometer. 

The operations involved in taking a reading are obvious. The 
commutator is first. worked till the required instrument is in 
circuit—that is, the hand of the commutator is put over the first 
contact devoted to that instrument. ‘The rheotome on wire Il. 1s 
now brought into action. In starting it, a deflection of the galva- 
nometer on ut, shows that the contacts are being truly reckoned 
from the zero point of the distant instrument, The hand of the 
rheotome is now steadily turned till a second deflection of the 


* Plate IV, is diagrammatic only. 


Joty—On the Reading of Meteorological Instruments. 1638 


galvanometer shows that the descending wire in the instrument 
has reached the mercury level. The rheotome is provided with a 
counter, on which the number of contacts is recorded. Reference 
to a Table gives at sight the reading of the instrument. This 
being recorded, the commutator hand is moved over the next con- 
tact, ¢.e. the second devoted to the instrument in question. The 
current through the rheotome has now been shunted at the instru- 
ment; the galvanometer for a moment returns to its zero position, 
but is immediately deflected again by the readjustment of the 
instrument into contact with wire ur. In the interval the 
movable limb of the distant imstrument has returned to its 
starting-point. | 

These operations being consecutive and of a purely mechanical 
nature, it will be evident that.a clockwork arrangement, to take 
automatically the readings of the various instruments and record 
them on divided paper, need not be very complicated or expensive. 
It will suffice to indicate briefly the nature of such an arrange- 
ment. 

A drum bearing divided paper is provided with a metallic stud 
at one extremity. This stud moves over the dise of the commu- 
tator, shown in Plate IV. as attached to wire 1. Intermittent 
motion is imparted to the drum through a suitable cam. The | 
_ intervals of rest are alternately long and short. That is, at a 
reading contact it halts, say, for two minutes, the reading being 
taken and recorded on the drum; it moves forward, resting for, 
say, thirty seconds at the succeeding -contact piece, while the 
instrument which has just been read is being restored to its zero 
position. Its next halt is again for two minutes, when another . 
instrument will be in circuit; and so on, the paper on the drum 
being divided into longitudinal divisions for the separate record of 
each. succeeding instrument. 

Parallel to the axis of the drum, and attached axially to the 
movable arm of the rheotome (on wire 11.), a spindle carrying a 
screw thread. revolves. The screw may be a fac-simile or an 
enlargement of those on the distant instruments. A. carriage, 
with small pricker attached, moves on the screw. Separate clock- 
work may work the rheotome, but gearing with the commutator is 
provided, so that, on the drum coming to rest over a contact, the 


164 Scientific Proceedings, Royal Dublin Society. 


rheotome is started, and continues making and breaking circuit on 
wire I1., moving the carriage and pricker at the same time longi- 
tudinally in front of the drum. When, after a certain number of 
contacts, the current returns by wire u1., a small electro-magnet 
comes into action, which is so arranged as to throw the rheotome 
out of gear, and simultaneously press the pricker forward on the 
paper carrying the drum. The reading is now recorded on the 
drum. The next movement of the drum to the succeeding contact 
allows of the adjustment of the distant instrument, and also of the 
carriage carrying the pricker. 

In conclusion, the following suggestions as to the forms which 
might be given to some of the instruments may not be out of 
place. 

In the case of the barometer, the siphon form of the instru- 
ment would be used, probably with wide vacuum chamber .and 
narrow air surface. ‘The thermometer, wet bulb thermometer, 
solar radiation thermometer, and terrestrial radiation thermometer, 
are suitable, as already described, with such modifications as the 
free and uninfluenced readings of the instruments in their several 
positions demand. For the rain-gauge I would suggest the fol- 
lowing arrangement :— 

The rain, collected in a suitable vessel, is conducted into a 
vertical cylinder, which forms the longer branch of a U tube. 
This tube contains mercury, the level of which in the shorter hmb 
is read in ascertaining the rainfall. ‘The height to which the 
mercury would be raised for a given fall of rain on a given 
receiving surface is a question of the relative diameters of the two - 
branches. The receiving surface being eight inches in diameter, 
it is easy to adopt such a diameter for the containing vessel that 
the pressure due to one inch of rainfall, say, since last reading, 
shall be represented by some three or four inches rise of the 
mercury. For the purpose of emptying the water-vessel after each 
reading, an electro-magnet is arranged to open a valve at the base 
of the vessel. The current to this electro-magnet is interrupted 
“automatically when the water has fallen to a certain zero level. 
This is effected by passing it through the mercury column in the 
short limb of the tube, the fall of the mercury breaking the cireuit 
at the desired point. 


Joty—On the Reading of Meteorological Instruments. 165 


Wind velocity, if treated by a Robinson’s anemometer, might 
be converted into and read as a vertical movement by an arrange- 
ment like that described by Professor Perry (Practical Mechanics, 
p. 241). Wind pressure would be more easily dealt with. 

An anemoscope would also be needed. This might consist of 
a disc, traversed by a metallic sector, attached to an exposed vane, 
the position of the sector, and so the direction of the wind, being 
ascertained by successive contacts. 


[ 166 | 


XXI.—THE OSTEOLOGY AND ARTHROLOGY OF THE HAD- 
DOCK (GADUS AGLEFINUS). By H. ST. JOHN 
BROOKS, B.A., M.B., B.Ca., Ssytor Moprraror in 
Naturat Scrence, Untv. Dus. ; Demonstrator of ANATOMY, 
CarmicHarL Cottece or Mepicine. (Plates V.-IX.) [Com- 


municated by AtexanpER Macattsrer, M. D., F. B.S. ] 


[Read, November 19, 1883.] 


iy this Paper is given a detailed description of the osteology and 
arthrology of a single type of Teleostean fish. In a work of this 
kind there is not likely to be found anything new, although 
several things in it are new to me, such as the existence of a 
cartilaginous rod passing from the atlas into the exoccipital bone, 
the peculiarity of the articulation of the first rib, the existence of a 
structure which is probably the homologue of the lower labial 
cartilage of the Elasmobranch fish, &e. 

It will be convenient to adopt the usual classification of the 
vertebrate skeleton into avial and appendicular parts—the former 
comprising the skull and vertebral column; the latter, the shoulder 
and pelvic girdles, with the bony axes of the limbs-: to these may. 
be added, in fishes, the interspinous bones and fin-rays. 

The skull may be divided into the cranium, or brain-case, and 
the bones of the face, the latter including the suspensorium and 
gill arches and the operculum, or gill cover. 

The cranium is composed of the following bones: the supra- 
occipital, frontal, and mesethmoid form the roof from behind for- 
wards in the middle line; more laterally, the parietal, epiotic, 
pterotic, and sphenotie, the two latter appearing also in the lateral 
walls, and the epiotic in the posterior wall; laterally the skull is 
bounded by the pterotic, opisthotic, sphenotic, prootic, alisphenoid, 
and prefrontal or ectethmoid ; posteriorly by the supraoccipital, 
eplotic, exoccipital, and small parts of opisthotie and basioceipital 
(see Pl. V., figs. 1, 2, and 3). The floor is formed by the basi- 
occipital, prootic, and prefrontal, and is closed below the middle 
portion by a membranous interorbital septum. 


Brooxs—The Osteology and Arthrology of the Haddock. 167 


If the fresh head be boiled for a short time, all but two of the 
facial bones (the parasphenoid and vomer) will become detached. 
These two bones will remain strongly connected to the brain-case, 
but are not included among the bones of the cranium, as the 
prootic bends inwards, and articulates with its fellow of the oppo- 
site side above the parasphenoid, thus entirely excluding the latter 
bone. The prefrontals in the same way exclude the vomer. The 
mesethmoid and prefrontal do not appear at first sight to form 
parts of the brain-case, but it will be remembered that the olfactory 
nerves pass out between the frontal and prefrontal, and end in the 
olfactory bulbs (Pl. VIL., fig. 18,3), which are morphologically part 
of the brain. These bulbs lie on the prefrontal, in a hollow bounded 
by the mesethmoid in front, partly roofed by the same, and 
bounded laterally by membrane. From between the mesethmoid 
and prefrontal a strong rod of cartilage projects backwards above 
the parasphenoid and vomer ; the membranous interorbital septum 
splits to enclose this, and is attached to the parasphenoid below. 

The hyomandibular, with the symplectic and quadrate, forms 
the suspensorium. ‘he quadrate, connected to the palate by the 
three pterygoids, forms, with these bones, the palato-quadrate arch. 
Thus, from the palate to the hyomandibular there is an immov- 
ably articulated chain of bones (Pl. VI., fig. 5), which is strength- 
ened by a strong splint, the preoperculum, which is united by 
suture to the quadrate and hyomandibular. ‘This arch articulates 
in two places with the skull; the head of the hyomandibular with 
a cavity formed by the pterotic, prootic, and sphenotic bones ; and 
the angle of the palate bone with a cartilaginous eminence de- 
veloped on the junction of the prefrontal and vomer. It is also 
suspended to the anterior end of the skull by strong ligaments. 
The quadrate furnishes an articular condyle to the mandible. 

The orbit is bounded above by the frontal and prefrontal. To 
_ the side of the latter is articulated a rather large lachrymal, to the 
back of which is attached a chain of five small suborbital bones, 
the last of which articulates with a projecting angle of the frontal, 
thus surrounding the orbit with a bony ring. The lachrymal pro- 
jects forwards in front of the orbit, overlapping the upper ends of 
the maxilla and premaxilla, and its internal edge is joined by 
ligamentous fibres to the nasal, the inner edge of which is con- 
nected in a similar way to the ethmoid. The posterior portion of 


168 Scientific Proceedings, Royal Dublin Society. 


the nasal bone overlies the nasal sacs. Other facial bones are the 
maxilla and premaxilla, and, connecting the skull with the shoulder 
girdle, is a forked post-temporal bone, from the concavity of which 
three small scales of bone pass to the inner, and one to the outer, 
ridge of the pterotic bone. Before passing to the hyoid apparatus 
and gills, a more particular description may be given of the above- 
mentioned bones. 

The frontal is the largest bone in the skull, and consists of two 
lateral halves fused. From the back of the upper surface projects 
an elevated ridge, which is continuous with the crest of the supra- 
occipital, the latter being wedged into a deep groove behind it. 
At the sides of this are a pair of ridges, continuous with the inner 
ridges of the pterotics. ‘These ridges are undermined from the 
outer side by deep grooves, which lodge mucous glandular tissue 
in the recent state. They communicate with a pair of curious 
oval apertures, which lie in front of the central ridge. Liaterally 
the bone projects over the orbit, forming its roof. On the under 
surface are seen two curved ridges, the anterior ends of which 
articulate with the prefrontals, and the posterior with the alisphe- 
noids. Just external to the articulation with the prefrontal is a 
groove, through which the nasal branch of the trigeminal nerve 
passes, and external to this the bone again articulates with the 
prefrontal. Stretching forwards over the latter, the frontal arti- 
culates with the ethmoid. TPosteriorly it articulates with the sphe- 
notic, parietal, and supraoccipital, and only just touches the inner 
ridge of the pterotic. The frontal overlaps every bone with which 
it articulates. 

The supraoccipital consists of a large elevated crest, continuous 
with the median ridge of the frontal, and of two small lateral 
portions. These articulate with the epiotics externally, and the 
articulations are overlapped by the parietals, which also articulate 
with the supraoccipital farther in front. ‘The under surface of the - 
crest articulates below with the exoccipitals, and the latter, uniting 
together, exclude the supraoccipital from the foramen magnum ; 
in front it articulates with the frontal. The back of the crest is 
closely connected by ligamentous fibres to the neural spine of the 
atlas. , 

The parietal is a curved scale of bone, presenting a well-marked 
ridge, which runs from before backwards, with an inclination out- 


Brooxs— The Osteology and Arthrology of the Haddock. 169 


wards. Just below this ridge it is perforated for a branch of the 
trigeminal nerve. It overlaps all the bones of the cranium with 
which it articulates, except the frontal. If the skull be softened 
in boiling water, it can be easily raised without disturbing the 
other bones. It is then seen to bridge over the hiatus! between 
the supraoccipital and pterotic bones, both of which it overlaps for 
some distance. It articulates also with the epiotic, sphenotic, frontal, 
and just touches the alisphenoid. ‘The tip of the inner limb of the 
‘ post-temporal fits into a groove on the upper surface behind. 

The epiotic is a very small bone, presenting a superior and an 
external surface, placed at right angles to each other, and a narrow 
posterior surface; above it articulates with the parietal, and just 
behind this supports the inner limb of the post-temporal ; internally 
it joins the supraoccipital ; below, the exoccipital, and externally 
the pterotic and opisthotic. Its cerebral surface is excavated by 
the posterior vertical semicircular canal. 

The exoccipital (Pl. VL., fig. 6) presents on its posterior surface a 
convexity from side to side, and a concavity from above downwards. 
The convexity forms a ridge, which is bent in such a manner as to 
present a concavity outwards, which overhangs a large foramen in 
the upper end of the bone for the vagus nerve. Below, the ridge 
ends in a sub-cylindrical extremity, which articulates with a pro- 
cess of the body of the atlas. Internal to the ridge, near where it 
joins the atlas, is a foramen for the first spinal nerve. The two 
exoccipitals, with the basioccipital, bound the foramen magnum. 
The inner borders articulate above with the supraoccipital ; below,” 
with each other. The sutures seen on the outside of the skull are 
with the supraoccipital, epiotic, opisthotic, and basioccipital. The 
‘outer portion of the bone stretches forwards on the inner surface 
of the opisthotic (inside the skull), and is connected to the prootic | 
and pterotic by a strip of cartilage. The upper part of the cere- 
bral surface of the bone is notched by the lower crus of the poste- 
rior vertical semicircular canal; and just below the internal opening 
of the foramen for the vagus nerve is a slender, foot-like process, 
which, articulating with a ridge on the upper surface of the basi- 


1 This space is also closed partially by cartilage, which underlies the parietal. 
2 That is, by the edges of the surface which is turned towards the commencement 
of the spinal cord. ; 


170 Scientific Proceedings, Royal Dublin Society. 


occipital, forms a bony hoop, which supports the large otolith, being 
applied against the posterior end of-its inner convex surface.’ 

The opisthotic is a thin bone, which is bent in such a manner 
as to present a notch posteriorly, which is occupied in the recent 
state by the anterior end of the kidney and the branches of the 
vagus nerve. From the upper margin a process projects inter- 
nally, which articulates with the epiotic. The pterotic articulates 
with the whole upper margin of the bone, and with the front of 
the above-mentioned process. In front it articulates with the 
prootic, and below with the basioccipital, and slightly with the 
parasphenoid. ‘The posterior margin bends slightly inwards, and 
articulates with the exoccipital (which also joins the lower edge of 
the epiotic process). The upper limb of the notch supports on its 
inner surface the external limb of the post-temporal. Near the — 
junction of the upper and anterior borders the bone is perforated 
by a foramen for the glosso-pharyngeal nerve. The cerebral sur- 
face is applied against the labyrinth, especially the external semi- 
circular canal. 

The pterotic forms the greater part of the lateral ridge or 
parotic process of the skull. Its outer surface is exeavated, 
affording origin to a group of muscles, which raises the gills. In 
front it articulates with the sphenotic and prootic bones, which 
complete, with it, the articular cavity for the hyomandibular, in 
the formation of which the pterotic takes the largest share. Below 
it articulates with the opisthotic.. It overlaps the sphenotic on the 
upper surface of the skull, but is overlapped by the latter bone on 
the lateral surface. It also articulates on the roof of the skull 
with the epiotic and parietal, and presents a thin ridge,” which 
forms a backward continuation of the outer ridge of the frontal. 
Its cerebral surface forms a bony ring around the external semi- 
circular canal. In front of this a process, going downwards and 
forwards, meets an ascending process of the prootic. This forms 
another ring around the anterior vertical semicircular canal and 
front of the vestibule, and the space in which they lie is closed 
above by the sphenotic. 


' The otoliths are not described here, as they belong more properly to the anatomy 
of the ear than to general osteology. 
? Spoken of above as the “inner ridge of the pterotic.”’ 


Brooxs— The Osteology and Arthrology of the Haddock. 171 


The sphenotic continues the parotic ridge forwards. It unites 
behind with the pterotic; above and behind, with the parietal ; 
above and in front, with the frontal; and below and in front, with 
the alisphenoid. ‘The sphenotic is often called ‘“ post-frontal”; but — 
the post-frontal is a membrane bone, while the sphenotie is pre- 
formed in cartilage.’ 

The alisphenoid is the smallest of the cranial bones, and is of 
an irregularly quadrilateral form. The upper edge unites with 
the frontal ; the posterior® with the sphenotic; the lower with the 
prootic. The anterior or free edge shows a groove, in which 
the nasal branch of the trigeminal nerve runs up to reach the 
frontal bone. To this edge the membranous interorbital septum 
is attached. ; 

The prootic presents on its anterior border a deep notch, 
through which the branches of the trigeminal and facial nerves 
pass out of the cranium. It unites below with its fellow of the 
opposite side, and below this with the parasphenoid, the three bones 
bounding a deep pit, which is open anteriorly, and gives origin to 
the recti muscles of the orbit. It articulates above with the ali- 
sphenoid, sphenotic, and pterotic, and behind with the opisthotic. It. 
covers the anterior portion of the vestibule and the anterior semi- 
circular canal. Behind it articulates with the basioccipital in the 
manner described below. 

The basioccipital presents posteriorly a concave articular sur- 
face for the atlas, which differs from the articulation of an ordinary 
vertebra only in being bevelled slightly above. Just above this it 
articulates with the exoccipitals, and in front and below this arti- 
culation it unites with the opisthotics. Mesially below, a tapering 
wedge of bone stretches forwards, and fits in between two similarly 
shaped processes of the parasphehoid, which, passing backwards, 
fit into grooves on each side of the basioccipital wedge. Viewed. 
from above, the bone shows a pair of deep excavations, separated 
by a median ridge, the anterior truncated extremity of which 
articulates with both prootics, which algo articulate with the ante- 
rior edge of the bone external to this. ‘These sutures are not seen 


1 A post-frontal and sphenotic may co-exist, as in Amia (Macalister, Morphology 
of Vertebrate Animals, p. 72). 
* More properly, postero-external. 
SCIEN. PROC. R,D.S.— VOL. LV. PY. LY. R 


172 Scientific Proceedings, Royal Dublin Society. 


on the outside of the skull, being concealed by the opisthotics and 
- parasphenoid. 

The mesethmoid! consists of a pyramid-shaped portion and a 
_ process, which stretches backwards from this to articulate with the 
frontal. The base of the pyramid rests on cartilage, which sepa- 
rates it from the vomer and prefrontals. The bone, however, 
touches the vomer in front, and two processes behind bridge over 
the cartilage and join the prefrontals. From the apex of the 
pyramid strong ligaments pass downwards and outwards to the 
maxillas, and the maxilla articulates with a cavity formed by the 
mesethmoid and vomer and the cartilage between them. 

The vomer, viewed from below, is shaped something like an 
arrow-head, the barbs pointing backwards. In front there are a 
few tecth attached to this (the under) surface. Above it articu- 
lates with the mesethmoid, prefrontal, and parasphenoid, and, 
curving round the anterior end of the latter bone, articulates with 
it also below. At the side, close behind the barbs of the arrow, is 
a depression for the attachment of a very strong ligament, which 
connects it to the palate bone. 

The parasphenoid is a long, strong bone, stretching along 
nearly the entire length of the base of the skull. In the middle 
it is somewhat constricted, and of a prismatic form. ‘In front of 
this its upper margin splits, to enclose the median cartilage, and 
the anterior fourth of the bone articulates with the vomer below 
and prefrontal above. Behind the constricted portion a pair of 
processes run upwards and outwards, and, articulating with the 
prootics, bound the pit for the orbital muscles. Behind it articu- 
lates with the opisthotics and basioccipital. 

The prefrontal is of a very irregular form. Behind it expands 
into a broad, curved plate, which articulates with the frontal. On 
the outer edge of this there is a projecting ridge, the truncated — 
end of which articulates with the lacrymal, and below this a liga- 
ment connecting it to the entopterygoid is attached. In front of 
this the bone narrows, and, where it joins the vomer, articulates 
with the angle of the palate bone. Below a process stretches 
backwards, articulating with the parasphenoid, and sheathing the 
side of the median cae, and where this peprO Cees joins the body 


1 Often called simply ‘‘ ethmoid.”’ 


? 


Brooxs—The Osteology and Arthrology of the Haddock. 173 


of the bone the two prefrontals unite above the‘cartilage. In front 
it joins both vomer and mesethmoid. 

The hyomandibular (P1.VI., fig.7) presents a head above, a body, 
and three processes. ‘The head is convex above, compressed from 
side to side, articulating with a hollow formed by the sphenotie, pte- 
rotic, and prootic bones. Below the head is a slightly constricted 
neck, and below this externally the body spreads out into a nearly 
smooth triangular surface, into which is inserted a muscle (Pl. VI, 
fig. 4, 7), which abducts the whole apparatus (suspensorum and 
operculum included). The anterior border of the bone is perforated 
in two places for the anterior and posterior branches of the facial 
nerve. ‘I'he anterior process spreads out in a fan-like form, and 
joins the metapterygoid in front, and just touches the symplectic. 
Behind it is connected to the symplectic by a triangular piece of 
cartilage, which articulates with the stylo-hyal.- The middle pro- 
cess articulates firmly with the preoperculum, passing external to it. 
Between these two processes runs a ridge, under which the tem- 
poral muscle dips to take additional origin. The posterior process,. 
stretching backwards, furnishes an articular condyle to the oper- 
culum proper. 

The symplectic is of an elongated, triangular form, with the 
base above. ‘The latter is connected to the hyomandibular by the 
triangular intercalary cartilage, aud (very slightly) in front of this 
by bone. The narrow apex fits into a groove in the inner surface 
of the quadrate. The anterior border fits into a longitudinal 
groove on the posterior border of the metapterygoid, and the pos- 
terior border bounds anteriorly a large fenestra (Pl. VI, fig. 5, a), 
through which the anterior branch of the facial nerve passes. 

The quadrate furnishes an articular condyle to the mandible 
below, which is concave from side to side, and convex from before 
backwards. From this runs a strong ridge backwards and up- 
wards, the postero-inferior edge of which is firmly united to the 
preoperculum, which slightly overlaps it. On the inner surface is 
the groove for the symplectic. Anteriorly a comparatively thin 
scale of bone springs from the ridge, and is grooved in front for 


_ the ectopterygoid, and above for the metapterygoid. 


The metapterygoid is a splint of bone, resembling the sym- 
plectic, but smaller, more slender, with the base downwards, and 
slightly curved, with the concavity outwards: The posterior border 

R2 


174 Scientific Proceedings, Royal Dublin Society. 


is grooved for the symplectic and anterior process of the hyoman- 
dibular. The base articulates with the qmadn Je, and in front it 
touches the ectopterygod. 

The ectopterygoid is a splint of bone, somewhat expanded 
behind, where it articulates with the quadrate. A small strip of 
cartilage persists between the two bones. In front it articulates 
with the palate; above and internally, with the entopterygoid. 
Its postero-superior angle articulates with a small portion of the 
metapterygoid, the latter overlapping it externally. 

The entopterygoid is a nearly flat, ovate-oblong scale of bone, 
the broader end being anterior. It lies on a plane internal to the 
ectopterygoid, to which it articulates by its lower edge. In front 
it joins the palate. Behind it tapers to a blunt point, which does 
not quite reach the metapterygoid. From the anterior end above 
and from the cartilage in front of this, a strong ligament passes to 
the prefrontal, being attached to a point below the lachrymal arti- 
culation.” 

The palate bone consists of an irregularly quadrilateral ae 
or body behind, and a sub-cylindrical process in front. ‘The pro- 
cess does not continue the axis of the body, but bends downwards 
and slightly outwards. Its anterior end articulates with the upper 
end of the maxilla, and the lower surface of the lachrymal slides 
over it above. From its upper border, where it joins the body, a 
strong ligament connects it to the apex of the anterior superior 
process of the premaxilla of the opposite side. Just behind and 
internal to this it is excavated, to articulate with a cartilaginous 
eminence on the junction of the prefrontal and vomer. It articu- 
lates behind with the ento- and ecto-pterygoids—with the former 
above and internally, the line of union being straight, and partly © 
occupied by cartilage; and with the latter below and externally, — 
by a splintery, serrated suture. Irom the inner side of the ante- 
rior part of the body a strong ligament is given off to a groove in 
the side of the anterior end of the vomer. 

In front of the ethmoid is a piece of cartilage which supports 
the maxilla and premaxilla: it will be spoken of as the pre-eth- 
moid cartilage for convenience of reference.* 


'T have not met with any name for it in the English text-books. Cuvier (Lecons 
d’Anatomie Comparée, vol. ii., page 652) calls it ‘un cartilage sphérique sur lequel 


Brooxs—The Osteology and Arthrology of the Haddock. 175 


The pre-ethmoid cartilage is of a nodular form, slightly 
flattened from side to side, convex above, the convexity being 
interrupted by a groove behind, where the palato-premaxillary 
ligaments cross it. The premaxille and maxille articulate with 
its front and sides. Posteriorly it presents a deep groove, which 
slides on the sharp anterior edge of the ethmoid. Abeve it is 
overlapped by the nasal bones. It is connected to the maxillee 
and premaxille by ligaments, and by weak He auienione fibres to 
the nasals and ethmoid. 

The premaxilla (Pl. VIL., fig. 9) is a small, curved ne , bearing 
teeth on its lower surface. Superiorly, it presents two processes ; 
and inferiorly, one. The anterior superior process presents a groove 
(Pl. VII., fig. 9, 4) on its inner surface, which affords attachment 
to a ligamentous substance, connecting it to its fellow of the oppo- 
site side. Just behind this (2) it articulates with the pre-ethmoid 
eartilage, and, behind the articulation (3), a ligament connects it 
with the cartilage. From the apex (1) passes a strong lgament 
to the palate bone of the opposite side. The posterior superior 
process presents postero-internally a little condyle (5), which arti- 
culates with the maxilla, a bi-concave disk of fibro-cartilage being 
interposed. he inferior process (7) slides on the inner side of 
the maxilla, and keeps the premaxiila from displacement outwards, 
especially when the mouth is closed. From the inner side of the 
upper end (6) a ligament passes backwards to the maxilla, and 
from the lower end a weak ligament passes to join the anterior 
maxillo-mandibular ligament. 

The maxilla (Pl. VIL., fig. 10) is a rather slender, slightly curved 
bone, flattened (7.e. compressed from side to side) below, the upper 
end presenting posteriorly a convex articular head (fig. 10, 4), and 
anteriorly two processes—an external and an internal. The head 
articulates with a deep pit, formed by the ethmoid and vomer and 
the cartilage between them, an interarticular fibro-cartilage being 
interposed. ‘The internal process gives attachment to a ligament 
(2) going to the ‘pre-ethmoid cartilage. Anteriorly it articulates 
with the premaxilla (6), and gives attachment to the premaxillo- 
maxillary ligament (1), and just below this presents a little spur 


s’opére le mouvement de la machoire,’ and Meckel (Anatomie Comparée, French 
edition, vol. ii., page 500) calls it ‘‘un cartilage articulaire, triangulaire.”’ 


176 Scientific Proceedings, Royal Dublin Society. 


(3), into which a muscle’ is inserted. From the outer surface of 
the base of the external process (5) a ligament passes to the upper 
and anterior part of the ethmoid, which is crossed by the palato- 
premaxillary ligament externally. Between the two processes is a 
recess, which slides on the pre-ethmoid cartilage. Below the head 

is a slightly constricted neck, on the postero-external surface of 
which is a smooth facet (7) for the end of the palate bone, and 
below this, on the posterior border, the posterior maxillo-mandi- 
bular ligament is attached. This passes to the outer side of the 
os articulare, just in front of the articular cavity-of the mandible. 
From the anterior angle of the lower end (9) the anterior maxillo- 
mandibular ligament passes to the outer side of the dentary, near 
the symphysis menti. 

The mandible consists of three bones—articular, dentary, and 
angular.’ 

The articular presents, on its upper surface posteriorly, an arti- 
cular cavity for the quadrate, which is concave from before back- 
wards, and slightly convex from side to side. In front of this the 
bone spreads out into a thin triangular plate. Below and in front 
of the articular cavity, a process stretches downwards and forwards, 
forming an angle with the rest of the bone, into which part of the 
dentary fits externally. Internally, between this process and a 
ridge which stretches downwards from the back part of the arti 
cular cavity, is a deep groove, into which the angular fits. Below 
the triangular plate is a strong ridge, the lower border of which 
jos edge to edge with a ridge which runs along the middle of 
the dentary. On the inner surface of the ridge, near its posterior — 
end, is a projecting tubercle, into which the tendon of the tem- 
poral muscle is inserted. From this tubercle a persistent rod of 
cartilage (Meckel’s) extends forwards, lying above and internal to 
. the ridge (which supports it), and, with the anterior extremity of the 
above-mentioned triangular plate, fits into the hollow of the dentary. 

The dentary bears teeth’ on its upper surface (which opposes 
the premaxilla). The teeth are all small and curved, the points 
being bent towards the cavity of the mouta. On the premaxilla 
there are about eight rows, of twenty to thirty in a row. The 


1 Regarded as the analogue of the masseter by Cuvier. (See Pl. VII., fig. 13.) 
2 T have looked in vain for a splenial ossification. 


Brooxs—The Osteology and Arthrology of the Haddock. 177 


larger teeth are in the outer series. On the mandible they are 
not so numerous, and are more uniform in size. The dentary 
bends inwards in front to join its fellow of the opposite side. The 
dentigerous edge is continued upwards and backwards into a 
process, which nearly touches the upper angle of the articular, to 
which it is bound by ligamentous fibres. A strong ridge runs 
from before backwards along the middle of the bone, and is 
connected to the dentigerous border externally by a thin osseous 
lamella, and internally by a somewhat similar lamella, which, 
however, extends farther backwards. Into the space between 
these two scales of bone the articular, with Meckel’s cartilage, fits. 

The angular is a small, irregular nodule of bone, which unites 
by suture with the articular in the manner above-mentioned. A 
strong ligament connects its posterior border with the interoper- 
culum. 

The nasal (Pl. VIL., fig. 14) is a scale of bone, curved im such a 
manner as to produce a gutter-like depression on its upper surface, 
running from before backwards. ‘This is filled with mucous glan- 
dular tissue in the recent state. Its internal edge touches its fellow 
in front. Behind, for a short distance, it is in contact with the 
ethmoid. The external edge touches the lachrymal, and the ante- 
rior end overlies the maxilla and premaxilla. ‘T'o all these bones, 
and also to the pre-ethmoid cartilage, it is connected by liga- 
mentous fibres. 

_ The lachrymal (PI. VL., fig. 4, 4) presents above a stout ridge, 
which runs parallel to the outer border of the nasal. This splits 
below into two laminze, of which the external extends the lower . 
down. Its posterior superior angle articulates with the prefrontal. 

The suborbitals are five small bones built on the type of the 
lachrymal; namely, a ridge next the orbit splitting peripherally 
into two lamine. 

The preoperculum (Pl. VL., fig. 5, 8) is another bone of this type, 
the ridge being in front, curved, with the concavity forwards. The 
internal lamina (as in the lachrymal and syborbitals) is the larger, 
and it extends farther backwards than the external, The ridge 

articulates with the quadrate below, and is overlapped by the 
middle process of the hyomandibular above. From the middle of 
the concavity a scale of bone extends upwards and forwards, and 
is wedged between the anterior and middle processes of the hyo- 


178 Scientific Proceedings, Royal Dublin Society. 


mandibular, and also partially overlaps the triangular intercalary 

cartilage. The upper end of the bone articulates with the posterior 
process of the hyomandibular. ‘The preoperculum is connected 
behind and below to the other three bones of the gill-cover. 

The interoperculum (Pl. V., fig. 11) is a long, thin bone, con- 
nected above with the preoperculum, behind with the suboper- 
culum, and in front with the mandible. Near the posterior end a 
strong spur of bone projects from the internal surface, in front 
of which a concave articular surface is formed, which supports the 
articulation of the stylohyal with the epihyal. 

The suboperculum is a curved scale of bone, lying below the 
operculum proper, which overlaps it. It is also overlapped by the - 
preoperculum and interoperculum, and is connected to these three 
bones by ligamentous fibres. 

The operculum proper is irregularly triangular. The superior 
angle presents, on its internal surface, an articular cavity for the 
‘end of the posterior process of the hyomandibular. The upper 
border is nearly straight; the anterior, convex; and the inferior, 
concave. . Internally, a groove runs from the articular cavity to 
the posterior angle for the insertion of a muscle, which adducts 
the bone (see Pl. V., fig. 12). 

The ligaments which have been mentioned above may be re- 
capitulated as follows :—Palato-premaxillary (see Pl. VII., fig. 
13), palato-vomerine, ento-pterygoid-prefrontal, maxillo-ethmoidal : 
these are all very strong. Distinct ligaments also connect the max- 
illa with the premaxilla, and both these bones with the pre-ethmoid 
cartilage; ligamentous fibres connect the lachrymals and nasals to 
all the surrounding bones; in particular, a strong network of fibres — 
binds the two premaxillas together, and passing upwards, covers 
the anterior ends of the lachrymals and nasals. The pre-ethmoid 
cartilage is entirely hyaline; so is the strong rod of persistent 
cartilage,' which hes between the ethmoid, vomer, prefrontal, and 
parasphenoid ; the disks of fibro-cartilage between the maxilla and 
ethmoid, and between the maxilla and premaxilla, are nearly all 
fibrous tissue on the peripher y, and nearly pure hyaline cartilage 
in the centre. Covering the lachrymal where it articulates with 
the pretrontal is a substance looking to the naked eye very like 


1 The unossified portion of the cranial trabecule. 


Brooxs— The Osteology and Arthrology of the Haddock. 179 


eartilage, but which is a peculiar condensed fibrous tissue.. The 
posterior maxillo-mandibular ligament is a band of white fibrous 
tissue, into which a small muscle! is inserted. ‘The anterior 
maxillo-mandibular ligament contains a very remarkable struc- 
ture—it is a rod-like body, attached to the dentary below, and 
tapering to a point above; in the lower part it consists of fibro- 
cartilage, containing large, well-developed cartilage cells in a 
network of white fibres; in the upper part it passes into fibrous 
tissue. The position of this body is- identical with that of the 
lower labial cartilage in elasmobranchs, the dentary being a mem- 
_ brane ossification covering Meckel’s cartilage (which forms the 
lower jaw in cartilaginous fishes), and from the fact of it contain- 
ing cartilage it may be the homologue of that structure; in the 
groove between the premaxilla and its inferior process there is a 
structure very similar in appearance, the tissue being identical 
with that of the wpper part of the lower ligament (containing no 
cartilage cells). Ligamentous fibres connect the two halves of the 
mandible together, and the four bones of the operculum are simi- 
larly connected ; a strong ligament passes from the interoperculum 
to the angular, and the head of the hyomandibular is kept in place 
by a capsular ligament. ‘Two other structures, though (strictly 
speaking) membranes, act somewhat the part of hgaments: these 
are, the interorbital septum and a membrane which connects the 
palatoquadrate arch with the skull. ‘The latter membrane is 
attached to the prootic and parasphenoid, and stretches across to 
the meta-, ento-, and ecto-pterygoid and palate bones, and forms 
the floor of the orbit. The interorbital septum consists of two sym- 
metrical laminz of fibres, which fuse into one in the centre of the 
structure ;* it is attached to the parasphenoid, prootic, alisphenoid, 
frontal, and prefrontal bones; it closes in the posterior (large) 
division of the. cranium (except at the uppermost part) in front; 
and is perforated by the optic, motor oculi, pathetic, and abducens 
nerves, while the trigeminal and facial nerves pass out between it 
and the prootic bone; below this the two layers fuse, and dipping 
into the pit for the origin of the recti muscles, are attached along 
the middle of the upper surface of the parasphenoid: above, the two 


1 Ciivier (op cit., vol. iv., i., p. 172) mentions this as ‘‘ un muscle carré.”’ 
2 Or perhaps a single lamina splitting above and below. 


180 Scientific Proceedings, Royal Dublin Society. 


layers are attached to the ridges on the under surface of the frontal 
bone, and are continued to the prefrontal, and, fusing together 
below, thus bound a prismatic space between them and the bone, in 
which the olfactory tracts lie. At its attachment to the para- 
sphenoid and prootic the interorbital septum is continuous with 
the infraorbital membrane (above described). 

The Hyoid and Branchial Arches—A typical branchial arch 
consists of four pieces, named, from above downwards, pharyngo- 
branchial, epibranchial, ceratobranchial, and hypobranchial. In 
some fishes (e.g. salmon) the three foremost arches are found 
nearly in this condition, but in many others the pharyngobran- | 
chials, which usually expand and bear teeth, show a great ten- 
dency to become distorted and fused together, and to have their 
articulations displaced: moreover, some of the hypobranchials 
may be wanting, the most constant of these four bones being 
the ceratobranchial, which is the only representative of the fifth 
arch. The hypobranchials are connected in the middle line by » 
series of small bones, or cartilages, the copule, the anterior of 
which is called the entoglossal, and the posterior the urohyal; the 
hyoid arch is built on the plan of a branchial arch, but the parts 
are more numerous, and peculiarly modified to perform different 
functions. The uppermost part of the arch, the hyomandibular, 
has been already described ; also the symplectic (which forms a 
sort of link between the hyoid and mandibular arches). The re- 
maining parts are the stylohyal, epihyal, ceratohyal, and’ two 
hypohyals. Below the hypohyals is a bone, often passed over 
unnoticed in text-books, for which the name of basibranchiostegal, 
applied to it by Parker, is perhaps the most convenient. 

The stylohyal (Pl. VIL., fig. 15) is a small rod-like bone, which, 
- articulating with the triangular intercalary cartilage above, passes 
downwards internal to the preoperculum, and articulates with the 
epihyal; the joint so formed is supported behind by an articular’ 
cavity on the inner side of the interoperculum. 

The epihyal is a triangular piece of bone, the apex articulating 
with the stylohyal in a movable joint, and the base immovably 
with the ceratohyal; it is separated from the latter bone below 
and externally by a strip of cartilage, but joins it internally by a 
splintery serrated suture. 

The ceratohyal, nearly three times as long. as the preceding 


Brooxs—The Osteology and Arthrology of the Haddock. 181 


bone, is connected to.it above and to the two hypohyals below ; 
the union to them is chiefly by the mediation of cartilage. The 
bone is flattened from side to side, and curved, so as to present a 
slight concavity upwards and forwards; part of the bone, thinner 
' than the rest, projects downwards and slightly outwards, and is 
marked with notch-like depressions on the ‘outer surface above, 
and on the inner below, for the branchiostegal rays ; the latter are 
slender, curved, flattened rods of bone, with a sharp edge on the 
middle of their convex border: they decrease in size from above 
downwards; four of them articulate with the outside, and three 
with the inside of the eeratohyal ; their direction is upwards, back- 
wards, and slightly outwards; they support the membranous inner 
gill-cover, by which they are connected to the inter- and sub- 
operculum. 

The two hypohyals, usually called inner and outer, may, from 
their position in the haddock, be more appropriately called superior 
‘ and inferior. The inferior is slightly anterior to the other; they 
are both small pyramidal bones, the bases of the pyramids being 
turned outwards; there is a considerable amount of cartilage 
between them and the ceratohyal, and in this, on the outside, is - 
seen the opening of a canal, which passes downwards and inwards, 
its Inner opening being bounded by the two lower bones, which are 
notched in this situation. This canal transmits a vessel, conveying 
arterial blood from the first branchial arch to the pseudobranchia. 

The superior hypohyals are the smaller; their apices articulate 
with the entoglossal cartilage, which keeps them apart. A ridge 
running along the inner side of the anterior border joins a similar 
ridge on the inferior hypohyal. 

The inferior hypohyals articulate with each other by their 
apices, which are anterior and internal, and by the anterior 
half of a ridge on their inner surface behind this; they form the 
chief support of the tongue: 

The basibranchiostegal (Pl. VIL., fig. 16, ¢) is a thin, irregularly 
quadrilateral plate of bone, the upper border being the thickest, 
shghtly grooved, and running into a distinct notch, where it meets 
the anterior border: from the margins of this notch a pair of strong 
ligaments pass to the apices of the inferior hypohyals: behind this 
the bone is connected by ligaments to the superier hypchyals. 
The anterior border is sharp and distinct, the posterior and inferior 


182 Scientific Proceedings, Royal Dublin Society. 


borders very irregular; the so-called sterno-hyoid muscle is in- 
serted into the whole of the side of the bone. 

The ceratobranchials of the first three arches are hardly dis- 
tinguishable from one another; that of the fourth arch, however, 
may be known by a little spur of bone, which projects downwards 
and inwards from the lower part of the bone. ‘These four bones 
are slender, rather long and curved, the convexity being down- 
wards and outwards. Running along the convexity is a deep 
groove for the branchial vessels and nerves, to the margins of 
which the gill filaments are attached. On the inner surface are 
the gill rakers, which form a double row on the first three arches, 
and a single one on the fourth; the anterior row on the first arch 
are long and curved, each ending in a single point, which is 
directed downwards; in all the other rows they are shorter, not 
curved, and end in five or six bristly points. The ceratobranchials 
articulate by a very movable joint with the epibranchials above, 
and somewhat less movably with the hypobranchials below. 
~The ceratobranchials of the fifth arch are shorter than the rest, 
and constitute the hypopharyngeal bones. They are much broader 

.than the others; the upper expanded surfaces, which,are opposed 
by the epipharyngeal bones, bear several series of teeth; they are. 
connected by ligamentous fibres, in front, to the ceratobranchials 
of the fourth arch. ‘The under surfaces show a pair of deep 
grooves for the attachment of the muscular fibres of the cesophagus. 
The lower ends are the less pointed, and are connected by liga- 
ment to the urohyal. 

The epibranchials are four small curved bones, which articu- 
late below with the ceratobranchials, and above with the epipha- 
ryngeal bones (pharyngobranchials) in a manner to be presently 
described. 

The anterior is the straightest and the most slender; the two 
posterior are greatly curved, and provided with processes, which 
articulate with each other, being connected below the articulation 
by a ligament. 

The first and second hypobranchials are small-curved bones, . 
grooved on their lower surface, articulating with the copule and 
with the first and second ceratobranchials. A distinct ligament 
passes from one to the other a little below the middle, and another 
ligament connects the second to the anterior process of the third. 


Brooxs— The Osteology and Arthrology of the Haddock. 183 


The third hypobranchial consists of a broad posterior part, hol- 
lowed below, and nearly flat above, and a curved anterior process; 
this process bends inwards, and is connected by a ligament to its 
fellow of the opposite side, thus arching over the cardiac aorta, 
and a large vein, which lies between their processes’ and the 
copulee; they underlie the hypobranchials of the second arch. 
The inner margins of the broad posterior part join the postero- 
lateral edges of a diamond-shaped ossification of the copule. Pos- 
teriorly the bone supports the third and fourth ceratobranchials, 
hence it may represent the third and fourth hypobranchials 
fused. 

The epipharyngeal bones consist of three pieces, which (for 
convenience) are referred to as a, b, and ¢ (see Pl. VIL., fig. 16). 
They are all concave and irregular above, and convex and dentige- 
rous below. They oppose the hypopharyngeal bones, and are sus- 
pended to the skull and vertebral column by muscles. The piece 
a is the most anterior, and its long axis runs backwards and 
inwards; parallel to this axis it articulates with 6 internally; its 
posterior angle nearly touches ¢; the anterior angle rises into a 
process, which supports the first epibranchial (fig. 16, 1) ; near the 
posterior angle it supports part of the second epibranchial, which 
forms a double condyle, to articulate with a and 6. The piece b 
is the largest, and is roughly triangular; it articulates with ¢ 
postero-externally, and with a externally; on the edge which 
articulates with c is a-ridge, 3, which is coated with cartilage, and 
supports part of the third and fourth epibranchials, which articu- 
late both with it and c. The piece ¢ is a small oval bone, which 
articulates with 6, as above mentioned ; the upper surface is con- 
cave, the hollow being filled with cartilage, which joins the ridge 
on 6, and supports the third and fourth epibranchials. 

The ossifications in the copulee consist of a diamond-shaped 
piece of bone, ending in a long spicule in front, and a shorter one 
behind. This bony part supports all the hypobranchials; a slender 
rod of cartilage underlies the front spicule, and is prolonged for- 
wards between the superior hypohyals, forming the entoglossal. 
From the posterior spicule a similar piece stretches backwards 
between the ceratohyals of the fourth arch, articulating with them, 
and is connected by ligament to the hypopharyngeal bones. This 
is the urohyal. 


184 Scientific Proceedings, Royal Dublin Society. 


The Vertebral Column.—The vertebral column consists of fifty- 
four vertebrae, twenty of which are. abdominal, and thirty-four 
caudal. Of the abdominal vertebree, all but the two anterior are 
provided with ribs, and all but the three anterior with parapo- 
physes. The caudal vertebrae have well-marked heemal spines. 
The body of the last vertebra is fused with ‘a triangular plate of 
bone, the coalesced hypurals. 

General Characters of Abdominal Vertebre.—lIi a vertebra from 
about the middle of the series (say the ninth, Pl. VIII., fig. 17) be 
examined, it will be found to consist of a centrum, which is nearly 
circular, slightly flattened from above downwards, a long neural 
spine surmounting the neurapophyses, and a pair of long parapo- 
physes, which support a rib and an epipleural spine. ‘The centrum 
is amphiceelous, the concavities being marked with concentric strize 
of a whiter colour than the rest of the bone. On the under surface 
is a longitudinal groove for the aorta, bounded on each side by a 
prominent ridge, and lying somewhat to the right side, in the 
floor of the groove, are two or three foramina. Outside the ridge 
is a large depression, and next in order, from the lower part of the 
side, springs the parapophysis, the base of attachment being 
strongest in front. Above this a prominent ridge forms a sort of 
second root to the parapophysis, and the upper part of the side of 
the bone is honeycombed with large and small foramina. From | 
the upper border of the bone in front springs the neurapophysis, 
and behind the posterior zygapophysis. Between the two is the 
“intervertebral” notch for the spinal nerves. The upper part of 
the body is nearly flat, dotted over with small foramina. The 
neurapophyses have the form of an elongated triangle. Springing 
from the body by a comparatively narrow pedicle, they stretch © 
forwards over the posterior zygopophyses of the vertebra in front, | 
articulating with them, and thus forming the anterior zygopo- 
physes. In front of this they nearly touch the neurapophyses of 
the next vertebra, roofing over the intervertebral foramina. They 
run directly into the neural spine, to which they are firmly anky- 
losed, thus bounding the neural canal above. ‘The neural spine is 
dagger-shaped, being flattened from before backwards; it inclines 
backwards, continuing the axis of the neurapophyses. The pos- 
terior zygapophyses are a pair of chisel-shaped spurs of bone, which 
receive the anterior zygopophyses between them; the articular 


Brooxs—The Osteology and Arthrology of the Haddock. 185 


surface slopes backwards, outwards, and slightly upwards. The 
parapophyses are long, curved, thin plates of bone, which incline 
downwards and backwards, the tips having a slight inclination 
inwards. On their upper surfaces a ridge runs from the centrum 
» for about half their length. The lower part of their posterior 
borders are folded over, as if hemmed. On this posterior border, 
near the tip, is seen a slight groove for the neck of the rib, and 
nearly half way to the body of the vertebra a little pit for the head 
of the epipleural spine. 

The first three vertebree are so peculiar, as to require separate 
description. In the others we notice the following differences :—. 
Following the transverse processes towards the tail, the inclination 
is more backwards, and the size slightly diminished; the “hem” 
at the posterior border becomes unrolled, and the anterior border 
approximates to it, so that the parapophysis takes the form of an 
inverted gutter, and in the posterior vertebre lacks altogether the 
pit for the epipleural spine. Following them forwards, the inclina- 
tion in the fourth vertebra (Pl. VIIL., fig. 19) is directly outwards ; 
the processes diminish rapidly in size, being very short in the fourth 
vertebra; the epipleural pit and the notch for the rib approach 
one another, and become confluent at the sixth vertebra. The 
- groove for the aorta inclines towards the middle line in front, and 
is nearly median at the fourth vertebra. Followed backwards, it 
also inclines to the middle line, becoming median about the four- 
teenth, and behind this it becomes indistinct. The first three 
vertebrae have no parapophyses, and the posterior zygapophyses 
have the articular surfaces looking directly upwards (which condi- 
tion is seen to a less extent in the fourth, fifth, and sixth). Those 
of the atlas and of the second vertebra are large and prominent. 
The neurapophyses of the first and second have distinctly less 
inclination backwards than that of the third or any of the others. 
The bodies of these three are very short, scarcely more than half 
the length of the ninth. 

The atlas (Pl. VIII, fig. 20) presents a strong neural spine, 
which is closely sannected by ligamentous fibres to the crest of the 
occipital bone. ‘The neurapophyses expand below into anterior 
zygapophyses, which are longer and stronger than those of the 
other vertebree. These articulate with the upper surface of the 
articular processes of the exoccipital bone (Pl. VI., fig. 6, 3). Im- 


186 Scientific Proceedings, Royal Dublin Society. 


mediately below these, and separated from them by a slit-like 
depression, are a pair of sub-cylindrical articular processes, which 
are united very firmly to the ends of those of the exoccipital bone. 
They are hollow, and contain a core of cartilage, which is conti- 
nued into the exoccipital. The lower surfaces of these processes 
articulate with the bevelled upper border of the basioccipital; and 
below this the joint resembles an ordinary articulation between two 
vertebree. On the side of the body, just below the posterior ay ga- 
pophyses, is a small pit, for the attachment of a a passing 
to the supraclavicle. 

The second vertebra presents nothing remarkable, except the 
shortness of body and absence of parapophyses common to the first 
three vertebrze 

The third vertebra (Pl. VIII., fig. 21) has a shorter neural 
spine than either the second or fourth. On the side of the body 
between the anterior and posterior zygapophyses is a deep pit, with 
which the head of the first rib movably articulates. 

Caudal Vertebre.— The eighth caudal may be taken as a 
typical member of the series. The centrum is more perfectly 
circular than that of an abdominal vertebra, and, owing to the 
absence of parapophyses, the sides appear more flattened. They 
are beautifully sculptured, the anterior and posterior edges being 
raised, and a ridge running along the middle, above and below 
which are large oval depressions. The neural spine is longer and 
more slender and curved than that of an abdominal vertebra, and 
with a greater backward inclination. The zygapophyses are not 
so well developed. ‘The heemal arch and spine are almost exactly 
like the neural, and provided with anterior and posterior zygapo- 
physes, which are, however, more imperfect than the superior. 


1 On removing the bone from the surface of this cartilage, it is seen to be attached 
by its broader end to the atlas. It passes from thence into the exoccipital bone, where © 
it tapers to a point. If.it be removed entire, and surrounded by a thin shell of bone, 
and a longitudinal section made, it is seen to be composed, entirely of hyaline cartilage, 
the cartilage passing into the osseous tissue of the atlas behind, and into that of the 
exoccipital in front. It presents the appearance of an ‘extosteal ossification extending 
from the atlas, and a similar extension from the exoccipital bone around a continuous 
rod of cartilage. This seems to imply a continuity of tissue between the parachordal 
cartilages and the first vertebra, such as occurs in the sturgeon (accipenser) ; but this 
is so much opposed to our present knowledge of bony fishes, that it could not be 
accepted, unless corroborated. by embryological research. 


. 


Brooxs—The Osteology and Arthrology of the Haddock. 187 


The centrum, in both the neural and hemal canals, is hollowed 
by a central depression, the hemal. being the deeper. Followed 
towards the tail, the vertebree become gradually smaller, and in 
the last ten the spines are nearly straight, and are studded with 
little bony knobs, giving them a knotted appearance. In the 
antepenultimate vertebra the spines look like hypural bones. The 
penultimate has no spines, but articulates with two hypural bones 
below and two similarly-shaped bones above. The last vertebra is 
ankylosed to a terminal, triangular, bony plate. Followed for- 
wards beyond the fifth caudal, the hemal canal rapidly widens. 
On the fourth caudal a ridge appears on the Side of the heemapo- 
physis. This becomes more pronounced on the third (PIR Vallee 
fig. 22), and presents a secondary ridge in front. The hemal canal 
is now very wide. In the second the ridges are stronger, and the 
anterior folded inwards, and their extremity projects like a trans- 
verse process. The first is a further exaggeration of this condition, 
and the vertebra appears to have a pair of parapophyses nearly 
identical in shape with those of the last abdominal, and in series 
with them, but connected near their lower ends, by a ribbon-like 
piece of bone, with a short hemal spine. All the above-described 
ridges are in series with the parapophyses. Owing to the increase 
in size of the hemal canal in the anterior caudal vertebra, the 
spines become shorter, though their tips are nearly the same abso- 
lute distance from the centra. 

The ribs, eighteen in number, are slender, curved bones, all of 
which articulate with the parapophyses, except the first ; the middle 
are the longest, about two inches,' and the last is a very slender 
bone of about half an inch in length; the general inclination is 
downwards and slightly backwards; the posterior ribs also incline 
inwards, being in series with the lower part of the hemal arches 
of the anterior caudals. The first rib differs both in shape and in 
manner of articulation from any of the others; it is stouter pro- 
_portionally, and is from one-half to three-quarters of an inch in 
length ;! the head is sunk in the above-described pit, in the body 
of the third vertebra; at a point about the middle of its dorsal 
surface it supports the first epipleural spine, which is about twice 
the length of the rib. The second rib is about the length of the 


' In a haddock of thirty inches. 


SCIEN. PROC. R.D.S.-—-VOL, IV. PT. IY. ‘ Ss 


188 Scientific Proceedings, Royal Dublin Society. 


first, but more curved and far more slender; it articulates below, 
but in contact with, the second epipleural spine, with a groove on 
the postero-inferior surface cf the parapophysis of the fourth ver- 
tebra (Pl. VIII., fig. 19). The third rib is similar, but more on the 
posterior border of the parapophysis; the fourth rib and epipleural 
spine are in contact for a shorter distance, and the parapophysis 
being longer, the two bones are removed farther from the body of 
the vertebra; the sixth rib and epipleural spine do not come in con- - 
. tact, the former being nearer the tip of the parapophysis; behind 
this they get farther apart, the ninth rib being about half an inch 
from the epipleural ‘spine. All the ribs behind the fiith articulate 
with the postericr borders of the parapophyses (which are generally 
grooved for them)—the neck of the rib only articulating, and the 
head projecting into the lateral muscle. 

The epipleural spines are curved bones resembling the ribs, but 
stronger; the anterior nine being large (1 to 2 inches), but be- 
hind this they diminish rapidly, and disappear about the four- 
teenth. The first is supported entirely by the first rib, and the 
next four partly by rib and partly by parapophysis; behind this 
they articulate with small depressions about the middle of the 
posterior border of the parapophyses. ‘Their direction is upwards, 
backwards, and outwards. 

The Interspinous Bones and Fin-rays.—The general form of an. 
interspinous bone (interhemal or interneural) is a straight (some- 
times curved) rod of bone, joined above at an obtuse angle with 
a thicker piece; the latter is hollowed at the end, and contains 
cartilage, which is prolonged into a rounded knob which supports 
the fin-rays; near the superior extremity of the bone in front is 
a saucer-like depression, formed by a prominent flange of bone; 
this supports the cartilaginous head of the interspinous bone in 
front and its articulation with the fin-rays. ‘The first and second 
(most anterior) interneurals are very large, and expanded from 
before backwards, being the result of the fusion of several indi- 
viduals. 

The above description applies to the dorsal and anal fins; in the 
caudal fins there are no interspinous bones (unless the hypural 
bones be regarded as such),' but in its anterior part there are . 


1“ Generally the hypurals are the interspinous bones alone, the arches being here 
obsolete’? (Macalister, op. ¢it. page 74). 


Brooxs—Zhe Osteology and Arthrology of the Haddock. 189 


wedge-shaped interspinous pieces of condensed fibrous tissue, the 
ends of which are-embraced by the fin-rays; behind this the fin- 
rays are in close juxtaposition to the hypural bones, a small quan- 
tity of the same fibrous tissue lying between their bases. 

Each fin-ray is composed of two long, slender rods of bone, 
tapering to a very fine point ; these are closely bound together, 
but diverge at their bases to embrace the cartilaginous continua- 
tion of the interspinous bone; at this part they are enlarged, and 
present several tubercles for the insertion of the elevator and de- 
pressor muscles of the fin, and for the attachment of ligaments. 

The ligaments’ of the vertebral column are neither numerous 
nor very distinct. 

Strips of fibro-cartilage bind the edges of the centra together, 
and membranous interspinous ligaments exist ; in the region of the 
fins these expand into a dense network of fibrous and elastic tissue, 
which binds the interspinous bones to the tips of the neural (or 
hemal) spines. The articulation between the interspinous bones 
and fin-rays is surrounded by a sort of capsular ligament, which 
is continuous with bundles of fibres which bind the distal ends of . 
the interspinous bones together. The ligamentum subflavum is 
a strong band of elastic tissue, which occupies a space im the upper 
part of the neural canal, separated by a slight constriction from 
the lower part, or true neural canal. A ligament connects the 
anterior and posterior zyapophyses, and above this is a strength- 
ened portion of the interspinous ligament; these are best seen in 
the anterior vertebree. 

The Shoulder-girdle and Pectoral Fin.—The shoulder-girdle 
‘consists of two bones, developed from cartilage—the scapula and 
coracoid—and several membrane bones—the clavicle (Pl. IX., 
fig. 24), supra-clavicle, and post-clavicle; to these may be added 
the post-temporal (Pl. IX., fig. 25), as belonging more properly to 
the shoulder than to the endl 

The clavicle, being the largest bone, and articulating with four 
of the others, may be described first: it is a curved bone, the con- 
cavity being forwards, and the long axis running downwards and 
forwards ; above it is compressed from side to side; below it forms 
an elongated cone, sharply pointed at the inferior extremity, and 
consisting of dense, compact tissue, solid to the very centre; the 
inferior extremity touches its fellow of the opposite side, being 


190 Scientific Proceedings, Royal Dublin Society. 


bound to it by a few ligamentous fibres. Viewed from within, the 
conoidal part passes rather abruptly into the flattened portion, the 
posterior border of the latter being continued some distance down 
the former, as a prominent ridge; with the inner side of the end of 
this ridge the inferior angle of the coracoid articulates; another 
ridge, which projects internally, is seen along the anterior border ; 
this runs into the superior angle of the bone above, while below it 
is lost where it joins the conoidal portion; near its lower end a 
thin shelf-like scale of bone diverges from it, and runs obliquely © 
backwards and upwards to the posterior border; between these two 
(the ridge and the shelf) is a piece of cartilage, to which the ante- 
rior process of the coracoid is fixed, while the upper part of the 
shelf supports the scapula, which also articulates with the anterior 
border above it. The outer surface of the bone is-marked by 
several grooves and ridges, for the attachment of muscles; below 
the pointed superior process is a deep, vertical groove, with which 
the supra-clavicle articulates. 

The scapula is a slightly-curved scale of bone, deeply notched 
below; the upper and anterior borders articulate with the cla- 
vicle, and the inferior border on each side of the notch joins the 
coracoid, bounding the coraco-scapular fenestra; the posterior bor- 
der supports a piece of cartilage, which is embraced by the anterior 
fin-ray, and below and behind this the first (or anterior), and part — 
of the second, of the three radialia; these do not come in contact 
with it, being separated by a strip of cartilage. 

The coracoid consists of a relatively thick, triangular portion 
above and behind (Pl. IX., fic. 24, a), a more elongated triangular 
portion above and in front, 6, and a rod-like piece, which runs 
downwards from the junction of the other two, c. These are con- 
nected by intervening thin lamine.’ According -to Parker, these 
three pieces represent the pree-coracoid, meso-coracoid, and coracoid 
proper respectively.” The pree- and meso-coracoid articulate with 
the scapula ; the meso-coracoid also with the clavicle; and the cora- 
coid proper with the clavicle only. The prae-coracoid supports the 
remaining radialia and the metapterygial basale. 


' “ Periosteal spaces’’ (Parker, On the Structure and Development of the Shoulder- 
girdle and Sternum, page 53). 
2 Loe. cit. 


Brooxs—The Osteology and Arthrology of the Haddock. 191 


The post-clavicle is a rod-like bone, pointed below, but ex- 
panded and flattened from side to side above. It is connected to 
the clavicle chiefly by muscle, the anterior superior angle, which is 
slightly overlapped by the posterior superior angle of the clavicle, 
being connected to the latter by a few ligamentous fibres. Its 
long axis is downwards and slightly backwards, forming an angle 
of about 45° with that of the clavicle. 

The supra-clavicle (Pl. IX., fig. 25, a) is a thick, peg-like piece 
of bone, sharply pointed below and bevelled internally where it fits 
into the groove in the clavicle, truncated above and bevelled exter- 
nally where it is overlapped by the post-temporal, an interosseous 
‘ligament binding them together. 

The post- Esoral (Pl. [X., fig. 25; 6) presents a massive, ovate 
body below, which articulates ithe the supra-clavicle, and two limbs 
above—an internal and an external. The internal, which is much 
the larger, is curved and solid and rounded behind, but thin and 
excavated on its under surface in front; it ends in a sharp point, 
which fits into a groove on the upper surface of the parietal, and 
just behind this it articulates with the epiotic. The internal limb 
articulates with the inner surface of the opisthotic. Between the 
two limbs are four supra-temporals. These are thin, irregular, 
subcutaneous scales of bone, which are curved so as to form a 
gutter on their upper surface, which is occupied by mucous glands 
in the recent state. Three of these are arranged end to end along 
the inner limb, lying close to the epiotic and parietal. The other 
lies near the outer limb, and is applied against the pterotic. 
Behind these four.is a much smaller scale, which occupies the 
posterior part of the notch on the upper surface of the bone, at the 
junction of the inner limb and the body. This may be a filth 
supra-temporal, or the first “lateral line bone.”’? 

’ The mesopterygial basale is represented by the piece of carti- 
lage which is embraced by the base of the anterior fin-ray. Below 
and behind this are the three radialia and the metapterygial basale. 
These are small hour-glass-shaped bones, with the exception of the 
first, or anterior radiale, which is somewhat semilunar in form. 
They are connected toa strip of cartilage which occupies the 
bifurcation of the proximal ends of the fin-rays. 


1 Of. Parker on Cottus bubalis (op. cit., page 43). 


192 Scientific Proceedings, Royal Dublin Society. 


The pectoral fin consists of about nineteen rays, each of which 
is composed of two pieces firmly united together. These diverge — 
at the base, and include within them a strip of cartilage, which is 
connected to the glenoid facet of the scapula and to the three 
radialia and the metapterygial basale. At their basal ends the rays 
are somewhat expanded, and present a double row of tubercles. 
Those of the inside (for the insertion of the double row of the 
tendons of the adductor muscles of the fin) are more largely 
developed, and lie farther apart than the outer ones. The latter 
are for the abductor muscles, and lie close together. The rays are 
marked with transverse constrictions, especially near their distal 
extremities. ‘They continue as single rods for more than half their 
length, and then split longitudinally into halves, which show a 
further tendency to divide at their distal extremities. This cleav- 
age is at right angles to the line of union of the two primary 
pieces of which each ray is composed. ‘The first or anterior ray is 
very short, not more than half the length of the fin, but is the 
strongest of all. ‘They increase in length up to the sixth, which 
is the longest. After this they diminish, the last two or three 
being’ very short and almost rudimentary. 

Ligamentous fibres hold the limbs of the post-temporal in 
place, and a strong rounded ligament keeps the upper end of 
the clavicle from displacement backwards; it is attached to the 
postero-internal border of the -supra-clavicle, and winds behind 
the superior process of the clavicle, piercing the lateral muscles, 
and notching the kidney, to be attached to the atlas in the manner 
above described. 

The pelvic bone is similar in structure to the coracoid. It pre- 
sents a thickish, triangular portion (Pl. I[X., fig. 26, a), whose free 
border, slightly curved, looks outwards and slightly backwards. 
To this is attached a strip of cartilage, which supports the fin-rays. 
A rod-like portion, 6, is attached to the inner angle of the above- 
mentioned piece, and stretches forwards and inwards, to be united 
with its fellow of the opposite side by cartilage, forming with it an 
angle of about 115°. This lies in the angle formed by the lower 
ends of the clavicles, and is connected to the latter by ligamentous 
and muscular fibres. A smaller flattened rod, c, passes backwards 
and inwards from the junction of the other two. ‘Thin lamin of 
bone connect these three pieces together. 


Brooxs—The Osteology and Arthrology of the Haddock. 193 


The fin-rays resemble those of the pectoral fin, but are much 
shorter, and only six in number. The difference between the bases 
of the inner and outer portions is less marked than in the pectoral. 

The otoliths are not described in this Paper, as they belong 
more properly to the anatomy of the ear than to the general 
osteology. 


' EXPLANATION OF THE FIGURES ON PLATES JV. ro IX. 


Fig. 1. The Skull from the side.—1, supra-occipital; 2, pterotic ; 
3, ex-occipital ; 4, opisthotic; 5, basi-occipital; 6, prootic ; 7, para- 
sphenoid ; 8, vomer; 9, articular surface for palate bone ; 10, ethmoid 
—the line points to the depression for the attachment of the maxillo- 
ethmoidal ligament; 11, prefrontal—the line points to the articular 
cavity for the lachrymal ; 12, frontal ; 13, sphenotic ; 14, placed in the 
space for the interorbital septum, points by a line to the alisphenoid ; 
a, foramen for glossopharyngeal nerve ; 0, articular cavity for head of 
hyomandibular. 

Hig. 2. The Skull from above.—1 to 11, as in fig. 1; 10’, apex of 
pyramidal portion of ethmoid;+15, epiotic; 16, parietal. _ 

Fig. 38. The Skull from behind.—1, supra-occipital; 2, epiotic ; 
3, pterotic ; 4, exoccipital—the line ends just above the foramen for 
the vagus nerve ; 5, opisthotic ; 6, basi-occipital ; 7, foramen for first 
spinal nerve. 

Fig. 4. Superficial Dissection of the Left Side of the Head.—1, points 
by five lines to the infra-orbital bones; 2, prefrontal; 3, hollow in 
nasal bone; 4, lachrymal; 5, premaxilla; 6, maxilla; 7, angle of 
mandible; 8, inter-operculum—beneath this are seen the branchio- 
stegal rays; 9, condyle of quadrate; 10, pre-operculum; 11, sub- 
operculum ; 12, operculum; 18, post-temporal; 14, ridge of pteérotic ; 
15, epiotic; 16, suture between supra-occipital and frontal; a, piece of 
skin left surrounding the double nasal opening; 6, b’, anterior, and 
c, posterior, maxillo-mandibular hgaments; d, ligament between inter- 
operculum and. mandible; e, temporal muscle; f, abductor muscle 
inserted into hyomandibular; g, abductor of the operculum. 

Fig. 5. Left Palato-quadrate Arcade, with the Hyomandibular and Gill 
Cover, seen from the outer side.—1, palate ;2, entopterygoid ; 8, meta- 
pterygoid ; 4, ectopterygoid; 5, quadrate; 6, interoperculum ; 7, sub- 
operculum ; 8, preoperculum ; 9, symplectic ; 10, triangular intercalary 
cartilage ; 11, operculum ; 12, hyomandibular ; a,, point of attachment 


194 Scientific Proceedings, Royal Dublin Society. 


of palato-premaxillary ligament; 6, of entopterygoid-prefrontal lga- 
ment; ¢, fenestra, through which passes posterior branch of facial 
nerve; d, for anterior branch of facial. 

Fig. 6. Right Exoccipital from behind (enlarged).—a, dotted line 
adjacent to the edge, which articulates with atlas; 6, with supra- 
occipital ; c, with epiotic; d, with opisthotic ; e, points by two lines to 
the extremities of the edge, which articulates with basioccipital ; 
f, with exoccipital of opposite side (the edges e and f are concealed by 
a and b in the figure); 1, foramen ‘for vagus nerve ; 2, for first spinal 
nerve; 8, articular process, which joins the lower articular process of 
the atlas (see fig. 20, 2), and contains a core of cartilage, which is con; 
tinued into the atlas. 

Fig. 7. Left Hyomandibular from the outer side.—1, head, which 
articulates with the cranium ; 2, foramen for anterior branch of facial ; 
8, part of anterior process, which joins the triangular interealary carti- 
lage; 4, condyle for the operculum ; 5, middle process. 

Fig. 8. Pre-ethmoid Cartilage from the left side.—1, line of attach- 
ment of ligament from premaxilla; 2, groove for palato-premaxillary 
ligaments ; 8, attachment of ligament from maxilla. 

Fig. 9. Right Premavilla: a, Inner; b, Outer View.—1, point of 
attachment of premaxillo-palatine hgament; 2, articular surface for 
pre-ethmoid cartilage; 8, dotted line, showing attachment of ligament 
to pre-ethmoid ; 4, for opposite premaxilla; 5, for maxilla; 6, attach- 
ment of ligament to maxilla; 7, inferior process. 

Fig. 10. Right mavilla: a,.From the inner side.—1, aileslicment of 
ligament to premaxilla; 2, maxillo-pre-ethmoid ligament; 3, tubercle 
for the insertion of a muscle (Cuvier’s ‘“‘ analogue of the masseter ’’) ; 
4, articulation with ethmoid. 0b. Mrom ‘the outer side—5, maxillo- 
ethmoid ligament; 6, for premaxilla; 7, for palate ; 8, for posterior ; 
and 9, for anterior, maxillo-mandibular ligaments. 

Fig. 11. Left Interoperculum from. the inner side—1, hollow, which 
supports the articulation of epi- with stylo-hyal. 

Fig. 12. Left Operculum from the inner side.—1, groove for insertion 
of adductor opereuli ; 2, cavity articulating with hyomandibular. 

Fig. 18. Deep Dissection of the Left Side of the Head.—1, nasal 
branch of trigeminal nerve crossing roof of orbit; 2, tip of ethmoid ; 
between 2 and 6 the maxillo-ethmoid ligaments; 8, olfactory bulb, 
4, pre-ethmoid cartilage; 5, apex of premaxilla; 6, maxilla—a little to 
the right of the line is seen the articulation of the palate ; 7, posterior 
mandibular ligament; between 5 and 8 palato-premaxillary ligament ; 
8, attachment of the same to palate bone—just behind this the articu- 


Brooxs—The Osteology and Arthrology of the Haddock. 198 


lation of palate and prefrontal; 9, anterior maxillo-mandibular liga- 
ment at its junction with a ligament from the premaxilla; 10, a small 
muscle (cut and thrown downwards), which arises by an aponeurosis 
from the preoperculum, and is inserted into the posterior maxullo- 
mandibular ligament (‘‘ muscle carré”’ of Cuvier); 11, articular surface 
for the lachrymal bone; 12, attachment of posterior maxillo-mandibu- 
lar ligament to mandible; 18, condyle of quadrate; 14, cut end of the 
superficial part of the temporal muscle ; 15, preoperculum ; 16, inferior 
maxillary division of trigeminal nerve; 17, superior maxillary division 
of the same ; 18, deeper part of the temporal muscle—this passes under 
the tendinous origin of a muscle which is inserted into a tubercle on 
the maxilla (see fig. 10, a +), and is considered by Cuvier to be the 
analogue of the masseter ;! it lies between the lines 16 and 17 in the 
figure; 19, condyle of hyomandibular for the operculum ; 20, articular 
head of hyomandibular; 21, adductor muscle of hyomand put 22, 
ridge of pterotic. 

Fig. 14. Right Nasal Bone from above.—a, posterior extremity ; 
b, outer edge. 

Fig. 15. Left Half of Hyoid Arch from the outer side—1, stylohyal ; 
2, epihyal; 3, ceratohyal; 4, superior hypohyal ; 5, inferior hypohyal ; 
a, foramen, which transmits the artery to the pseudobranchia. 

Fig. 16. Bones of the Gill Arches of the Left Side, with the Basi- 
branchiostegal and the Ossification in the Copule.—a, b, and c, the three 
pieces of the epipharyngeal bone, from above ; 1, for articulation with 
epibranchial of first branchial arch; 2, for that of second arch; 3, for 
those of third and fourth arches ; d, basibranchiostegal, from the right 
side—the letter is placed near the posterior border ; ¢, ossification m 
the copule, from above; f, /’, f, hypobranchials, from above ; 
GGG 5.9. 5 ceratobranchials, from behind; h, hypopharyngeal bone, 
from behind; &, hk’, k”, k’”, epibranchials, from behind; 4, 4’, processes 
of epibranchials of third and fourth arches, which articulate with one 
another. 

Fig. 17. Ninth Abdominal Vertebra, from, before—1, neural spine ; 
2, neural canal—the line points to the constriction which separates the 
canal for the ligamentum subflavum from the true neural canal below ; 
3, centrum; 4, eroove for aorta—e and r point to the articular surfaces 
on the posterior surface of the parapophysis for the epipleural spines 
and ribs respectively. 


> as 


+ Op cit., vol. Iv. 1. p. 171. 
SCIEN. PROC. R.D.S.—VOL. IV. PT. Iv. dy 


196 Scientific Proceedings, Royal Dublin’ Society. 


Fig. 18. Fifth Abdominal Vertebra from before.—p, Parapophysis ; 
, epipleural spine; 7, rib. 

Fig. 19. Fourth Abdominal Vertebra from before.—Tietters as in 
1K US, 

Fig. 20. Atlas from the right side.—1, Anterior zygapophysis ; 2, 
lower articular process (for exoccipital); 8, posterior zygapophysis ; 
4, pit for attachment of ligament to supra-clavicle. 

Fig. 21. Third Abdominal Vertebra from before.—r, rib; e, epipleural 
spine. 

Fig, 22. The four last Abdominal and first three Caudal Vertebre from 
below and slightly from the right side.—1, Parapophysis of abdominal 
vertebra ; 2, process of hemal arch of first caudal; 4, ribbon-like piece 
of bone connecting the latter to 3, the hemal spine. 

Fig. 28. An Interspinous Bone (slightly enlarged\—a, from the side ; 
b, from before—1, Hollow portion, which is continuous with the piece 
of cartilage with which the fin-rays articulate ; 2, saucer-like portion, 
which supports the articulation of the interspinous bone and fin-ray 
next in front. 

Wig. 24, A. Shoulder Girdle and Fin of the left side from within.— 
a, b, ¢, coracoid—a, pre-coracoid; 6, meso-coracoid; c¢, coracoid 
proper; 1, scapula; 2, the anterior of the three radialia; 3, cartilage 
between coracoid, scapula, and clavicle; 4, clavicle—the line points to 
the conoidal portion ; 5, the metapterygial basale, B. Upper portion of 
the same (slightly reduced), with the scapula and coracoid removed, 
showing, 6, the shelf-like process of bone which supports the scapula, 
and, 7, the post-clavicle in its natural position. 

Fig. 25. Left Supra-clavicle, a, and Post-temporal, b, from above.— 
1, Outer or lower, and 2, inner or upper, limb of the post-temporal ; 
3, articular surface of supra-clavicle for post-temporal. 

Fig. 26. Left Pelvic Bone from above.—a, Portion of the bone which 
supports articular cartilage for the fin-rays—the cartilage is dotted ; 
b, rod-like portion—the line points to the extremity where it joins its 
fellow of the opposite side. 


Mon 


XXII.—NOTE ON THE BOTANICAL TOPOGRAPHICAL DI- 
VISIONS OF IRELAND. By W. R. McNAB, M.D., 
F.L.8., Professor of Botany, Royal College of Science, 
Ireland; Scientific Superintendent of the Royal Botanic 
Garden, Dublin. 


[Read, January 21, 1884.] 


Bzine at present engaged in the re-arrangement of the collection 
of British and Irish plants in the Herbarium at the Royal Botanic 
Garden, Glasnevin, it was necessary for me to consider what steps 
dught to be taken towards the formation of a collection illustrating 
the “Cybele Hibernica.”’ Special considerations rendered it advis- 
able to keep all the British and Irish plants together for the present, 
the space at my disposal not permitting of the formation of a special 
““ Cybele Hibernica” collection. All the advantages I wished for 
could, I found, be got by simply introducing a printed sheet into 
the Herbarium with each species, headed “ Cybele Hibernica,”’ and 
bearing the number, name, and the recorded distribution of the 
plant in Ireland. Taking Watson’s “ Topographical Botany” as a 
good model, it became necessary to revise the whole Botanical 
Topography of Ireland, and to bring the “ Districts” of Moore 
and More’s ‘‘ Cybele Hibernica” into greater conformity with the 
divisions adopted for England, Wales, and Scotland. At the same 
time it was of the utmost importance to make as little alteration as 
possible in Babington’s Districts as adopted by the Authors of the 
“Cybele Hibernica,”’ as all alterations would tend to produce con- 
fusion. Watson adopts a division into Provinces, Vice-provinces, 
and Vice-counties, for the “Cybele Britannica,” and Babington 
divided Ireland into Districts. I propose simply to adopt Babing- 
ton’s “ Districts,” but to call these “ Provinces,” distinguished not 
by a number only, but by a roman numeral anda name. In this 
way the name will obviate the necessity-of constantly referring to 
a map when any District or Province is mentioned by number. 
Vice-provinces, as adopted by Watson, are unnecessary in the 
Botanical Topography of Ireland. ‘The next division, that of Vice- 
counties, or of Counties and parts of Counties, must however be 


SCIEN, PROG. R.D.S.— VOL, IV. PT. Vs Z U 


198 Scientific Proceedings, Royal Dublin Society. 


adopted; and following the ‘Cybele Hibernica” as closely aspossible, 
we must at least adopt thirty-six Vice-counties. In the majority 
of cases these Vice-counties are the ordinary comital divisions, it being 
necessary in comparatively few cases to divide the county into two 
parts, although it is possible that in a few cases further subdivision 
might be made. In naming the Provinces the names of the four 
great Provinces of Ireland have been used; and it is only in the 
cases of Provinces VI. and VII. that this has been depaited from, 
and the terms West and Hast Shannon have been adopted, although 
the former does not all lie West of the Shannon. 

The following is a tabular view of the proposed Provinces and 
Vice-counties :— 


PROVINCES AND VICE-COUNTIES. 
PROVINCES. VICE-COUNTIES. 


T.—West Munster, ... .... 1 Kerry. 
2 South Cork. 


North Cork. 
Waterford. 
South Tipperary. 


II.—EHast Munster, 


is) 


Kilkenny. 
Carlow, 
Queen’s County. 


Wexford. 
10 Wicklow. 


NV. ==Nortl emster. 4 oc. ul Kaldare; 
12 Dublin. 
13 Meath. 
14 Louth. 


Vil.—West Shannon, ... .... 15 Limerick. 
: 16 Clare. 
17 Hast Galway. 


VIl.— Hast Shannon, ...... 18 North Tipperary. 
19 King’s County. 
20 Westmeath. 
21 Longford. 


II1I.—West Leinster, 


ODBAIgd We 


de) 


TV.—East Leinster, 


McNas—Wote on Botanical Topographical Divisions of Iredand. 199 


PROVINCES. VICE-COUNTIES. 


VIII.—West Connaught, ... ... 22 West Galway. 
23 West Mayo. 


IX.—Hast Connaught, ....... 24 Hast Mayo. 
25 Sligo. 
26 Leitrim. 
27 Roscommon. 


X.—South Ulster, ... .. 28 Fermanagh. 
29 Cavan. 

30 Monaghan. 
dl Tyrone. 

32 Armagh. 


XI.—West Ulster, + oe 988 Donegal andcity of Londonderry. 


PMH asimOlsieretn) a25 tes tote Dow. 
385 Antrim. 
36 Derry. 


By adopting these divisions it will be easy to record, on a single 
sheet, all the Vice-counties in which any given plant; has been 
observed, by simply marking off the number and name, while 
space will be left after each name for an entry of the authority or 
exact locality if necessary. Further, I believe, it will be a great 
advantage to students to have the “ Districts’ named instead of 
merely numbered ; and also it will be much more easy to compare 
the distribution of species: in Great Britain and Ireland now than it 
was formerly when totally different divisions were adopted. 


f.200 J 


XXIII.—DESCRIPTION OF AN APPARATUS FOR DEMON- 
STRATING SYSTEMS OF CLASSIFICATIONS, ETC. 
By ALFRED C. HADDON, M.A., Professor of Zoology, 
Royal College of Science, Ireland. 


[Read, January 21, 1884. ] 


A mernop of classification which would indicate the affinities of 
organisms to one another has for a long time been thg aim of 
biologists, and they have more or less succeeded, by arranging the 
names of the forms whose affinities they desired to illustrate in a 
given manner, and connecting them by means of lines. 

The older zoologists, for instance, were content with arranging 
the names in a continuous sequence, thus forming a linear series or 
a classification in one dimension of space. 

It was soon found that such an arrangement by no means indi- 
cated the real affinities, nay more, tended to retard a true conception 
of the animal kingdom as a whole; so recourse was had to arrang- 
ing the names in a dendritic manner on a flat surface, the length of 
the lines, their position, and their various ramifications illustrating 
the supposed relative position of the animals themselves. This 
constituted a classification in two dimensions of space. 

Some zoologists, however, have felt that even this method was 
insufficient to express their views; but, so far as I am aware, this 
want has not yet been supplied; and it has occurred to me that 
what was really required was a system which would more accu- 
rately render in space that well-known figure of speech—the 
Genealogical Tree—and that the facts of the case could be more 
closely represented by a solid method of classification—in other 
words, by a classification in three dimensions of space. 

Unfortunately such a system requires a special apparatus, and 
is not adapted for ordinary representation on plane surfaces; but 
the apparatus I propose is very simple, merely consisting of a series 
of glass plates placed vertically over one another, leaving a small 
space between each, and a number of small movable blocks. 

The exact method for supporting the glass plates is of no con- 


Hapvpon—On an Apparatus for Systems of Classifications, &c. 201 


sequence, and may be varied to any extent. ‘The apparatus which 
I employ consists of an oblong mahogany board, let into the cor- 
ners of which are four brass sockets; into these are inserted four 
brass standards which are pierced with holes at regular intervals, in 
such a manner that the holes in each end-standard are vis avis with 
those of its fellow, and are at the same time parallel with those at 
the opposite end. Through these holes brass wires are inserted, and 
it is upon these that the glass plates rest. This apparatus has the 
advantage of being readily taken to pieces, and in being quite por- 
table. 

The names should be printed on paper, then cut out and pasted 
on two faces of oblong blocks of wood, in such a manner that they 
ean be read in a front view or by looking down vertically upon the 
apparatus. A makeshift may be constructed by bending a small 
oblong piece of cardboard roofwise, and writing the name on one 
face of the anticlinal. . 

The several blocks may be linked together in the same plane by 
pins inserted in the sides, or to those of the plane above by pins 
placed either vertically or obliquely, and reaching to the upper 
glass plate. Any complicated system of linkage is thus possible. 

There are two obvious uses to which this apparatus can be put 
in Zoology, viz., to represent a classification of recent forms and 
for phylogeny. 

In a classification of recent forms, each plate might represent a 
stage of differentiation, and the arrangement of the forms on that 
superficies would indicate their inter-relationships. ‘The lower 
planes would naturally be chosen for the less differentiated types. 
An area on each plane could always be made by a coloured line to 
represent some special modification. Degraded animals might be 
tinted, and a black pin slanting from the higher to the degenerate 
form would graphically show that it was not an ascending type. 
Missing links between more or less widely-separated living animals 
could be appropriately supplied by names within brackets. 

For phylogeny the arrangement would be somewhat similar, 
except that each plate would represent some geological horizon, the 
name of which would be on a block placed in one corner. Every 
name in each geological epoch should be tinted in some distinctive 
colour, so as to distinguish at a glance its precise horizon (it would 
be well to adopt the Survey colouration). 


202 Scientific Proceedings, Royal Dublin Society. 


In the case before us only a general classification can be at- 
tempted, and degraded forms could only be represented by a 
special colour. 

This system presents us with certain advantages over the 
ordinary graphic methods: for instance—on each glass plate is a 
collection of the representatives of any group which occur in a 
particular stratum. These forms are the chronological data of the 
ordinary stratiographical geologist ; and it matters not to him how 
these may be arranged upon the plane. 

The philosophical paleeontologist arranges the names on each 
plane so as to indicate the relations of each animal to those preced- 
ing and succeeding it in time, as well as to its synchronous neigh- 
bours, and thus he gets a graphic view of the march of life; by 
looking from above down the vista of time he sees widely-separated 
recent animals gradually converging till they all unite in some 
form which, if at present unknown, must once have existed ; or, 
more accurately, diverging from such a common ancestor. It will 
also be made apparent that in every age there were forms which 
varied from the parent stem, which lived for a longer or a shorter 
period and then became extinct. 

Very valuable museum demonstrations could be made by fitting 
up a comparatively large apparatus, to the glass plates of which 
were cemented real fossils with their names. - Ammonites and 
Brachiopods, for instance, are well fitted for this purpose. Affini- 
ties and variations would in this case be illustrated by the actual 
specimens, and so be vividly impressed upon the mind. 

By drawing or etching on each glass plate a similar outline 
map of the world on Mercator’s projection, and by allocating one 
of the smaller subdivisions of the Cainozoic period to each, the 
migrations of animals could be indicated in terms of time and 
space. ‘This would naturally necessitate a separate series of 
plates. 

It is needless to dwell further upon the possibilities of such an 
apparatus ; for I feel confident that it will prove of use in many 
other ways, and in other branches of knowledge than in those 
indicated above. 

I may ‘add that I have employed this system for nearly two 
years, and have found it to answer admirably. 


[ee 


XXIV.—REMARKS ON THE UNUSUAL SUNRISES AND SUN- 
SETS WHICH CHARACTERISED THE CLOSE OF THE 
YEAR 1883. By REV. SAMUEL HAUGHTON, §.F.T.C.D., 
M.D., F.R.S. 


[Read, January 21, 1884 ]|! 
Tue older writers on Astronomy, such as Brinkley and Maddy; 
state that, on the average, twilight lasts until the sun is 18° below 


the horizon. From this it has been computed that the height of 
the twilight-producing atmosphere is 


40 miles on hypothesis of one reflexion, 


LA Gene 9 », two ” 
Foy lop ” op DURES) ey 
3 99 9 = ” »» four 9 


Herschel and Newcomb make no statement whatever as to the 
duration of twilight ; Chambers (in his compilation) says that the 
average depression of the sun is 18°, which is reduced to 16° or 17° 
in the tropics, but in England a depression ranging from 17° to 21° 
is required to put an end to the twilight phenomena. 

Dr. Ball informs me that Professor Schmidt, of Athens, gives 
(for that place) 15° 51’; and also that Liais (Paris) fixes the first 
twilight arc to set at 10° 41’, and the second are at 18° 18’. 

In the following conclusions, drawn from the phenomenal twi- 
lights of the autumn of 1888, I calculate the zenith distance of the 
sun, at the close of the phenomena, by the well-known formula 


cos 8 =a + ( cos h, 
where 
% = sun’s zenith distance. 
h = sun’s hour angle. 
a= sin X sin 6. 
(3 = cos X cos 0. 
Xd = latitude of place of observation. 
6 = declination of sun. 


204 Scientific Proceedings, Royal Dublin Society. 


Observation (1).—Mr. Bishop, observing at Honolulu, found 
the phenomenal sunsets to commence on the dth September, 1883, 
and to last up to 7 25™ P.M. 


Here A = 22°. 
d= 6° 16. 


This gives the sun’s place, at the close of the phenomena, 18° 22’ 
below the horizon. 

This indicates twilight phenomena intensified by some unusual 
cause, but does not denote an extension of twilight reflexion into 
regions of the air higher than the time-honoured traditional 40 
miles. 

The epoch of the main eruption of Krakatoa has nec fixed by 
General Strachey at August, 272 95 32", a.m. 

If the explosion of Krakatoa, on the 27th oe was the 
cause of the brilliant sunset at Honolulu, on the 5th September, 
the result is nothing short of miraculous ! 

The Editor of Nature writes, on the 20th December, with an 
enthusiastic glow worthy of the twilights :—‘‘'The extraordinary 
fact now comes out, that before even the lower currents had time 
to carry the volcanic products to a region so near the eruption as 
India, an upper current had taken them in a straight line vid the 
Seychelles, Cape Coast Castle, Trinidad, and Panama, to Hono- 
lulu; in fact very nearly back again to the Straits of Sunda!” 
[The note of admiration is not mine. | 

Tt is worth our while to calculate the rate at which this wonder- 
ful journey of volcanic dust was performed. The actual distance 
is 255° of a great circle, and the time of journey 9 days, from 
which I calculate the speed of the train to have been 82 miles 
per hour! This is absolutely incredible, and becomes still more so 
when we know that the phenomena observed at Honolulu on the 
5th September were unusual twilight phenomena, but had no 
connexion whatever with reflexion from the upper regions of 
the air. In point of fact, my calculation of the sun’s position 
disproves the presence of dust, or any reflecting substances in the 
upper air. 


Observation (2).—Dr. Ball (Dunsink).—“ Sunday evening, 30th 
December, was exceptionally fine, and the sunset was so well seen 


Haveuton— Unusual Sunrises and Sunsets at close of 18838. 205 


that the moon (though only 27 hours old) was well seen by 
Cathcart and myself from the roof of the Observatory. 

“We estimated that the twilight lasted certainly for two hours 
after sunset, and that for ten minutes longer there was still enough 
light in the western sky to distinguish it from other parts of the 
horizon. | 

“At 2 hours after sunset the sun was 15° 56’ below the 
horizon, and at 2 10™ it was 16° 51’ below the horizon.” 


Observation (3).—On the 25th December Mr. William Graves, 
observing at Kingstown, found it was “black night” at 5°30 p.m. 
This gives 14° 15’ below the horizon for the sun’s position. 


Observation (4).—Mr. Frederick Haughton, writing from Car- 
low, says, of the evening of 30th December :—“I have of course 
seen a good deal of the after-glow: some evenings the appearance 
is like the glare of lime-light at a theatre; the effect on grass or 
gardens very strange; with back to west every blade of grass is 
like fire, a bit of straw like a red hot needle; but facing the hight 
it is all lurid light and shade. Last night sun set by almanac at 
3°47; here the sun disappears 20 to 25 minutes before, owing to 
hills; at 4:30 the glow was splendid; at 5°10 I could see the 
second-hand of watch. 1 hour 23 minutes after sunset, or nearly 
12 hour after sun had vanished from us, a planet! from 4°30 to 
5°30 was in the glow; and from 5 to 5°30 was bright emerald 
green!” 

Supposing the termination of the phenomena to be at 5:40 p.m., 
this would correspond to a position of the sun 15° 15’ below the 
horizon. | 


1 Venus. 


208 | 


XXV.—A SIMPLE METHOD OF OBSERVING FAINT LINES 
WITH DIFFRACTION SPECTROSCOPES. By W. N. 
HARTLEY, F.R.S.E., &c., Professor of Chemistry, Royal 
College of Science, Ireland. 


[Read, January 21, 1884. ] 


In observing spark spectra with diffraction gratings there is gene- 
rally much difficulty attending the measurement of faint lines ; 
moreover, the eye becomes fatigued when regarding for any long 
period rays of one colour only, and in endeavouring to catch sight 
of the cross wires on a darkened field. During a spectroscopic 
examination of the rare earths contained in the mineral rhabdophane 
(“Chemical Society’s Journal’’—Transactions, vol. xli.,.p. 210), a 
somewhat painful experience led me to devise a means of not only 
giving relief to the eye, but of greatly facilitating the measure- 
ment of the lines. I work in a darkened room, the goniometer 
of the. spectroscope being illumined by a shaded lamp which 
stands to right of the telescope. The grating is movable, while 
the collimator and telescope are fixed in such a position as to 
include as small an angle between them as possible. The telescope 
being to the right of the collimator, a small gas jet is placed upon 
the left, the rays from which proceed to the grating and are re- 
flected into the field of the telescope. By the adjustment of this 
light the field may be illuminated in any colour of the spectrum, 
and by selecting that tint which is complementary to the colour of 
the lines to be measured, they are seen to stand out apparently 
in relief on a bright ground. ‘The intensity of the illumination 
of the field must, of course, be regulated according to the strength 
of the lines to be measured. Many of the lines in the spectrum 
of yttrium obtained from rhabdophane could not have been measured 
had it not been for this method of working. 


Pe 207 


XXVI—NOTES ON THE CLASSIFICATION OF THE BOULDER- 
CLAYS AND THEIR ASSOCIATED GRAVELS. By 
G. H. KINAHAN, M.R.I. A. | 


[Read, January 21, 1884. | 


THE phenomena to be observed in connexion with the boulder- 
clays and their associated gravels, &ec., especially in Ireland, are 
far from having been satisfactorily explained; it may therefore 
be allowable to make some remarks on them. 

It would appear as though the present confusion is in a great 
measure due to observers rushing to conclusions without sufficient 
and careful examination or thought, and also forgetting to com- 
pare the deposits that they would explain with those that are being 
laid down at the present time. 

There are three classes of more or less similar drifts, which are 
commonly called boulder-clay :-— 


Ist. The Ti1, or the Lower Boulder-clay. 
2nd. Moraine Drirt, or the Upper Boulder-clay. 
drd. GLAcIALoID Drirt. 


Nos. 1 and 2 are true glacial drifts; while No. 3 was originally 
glacial drift, but has subsequently been re-arranged, either by water 
or atmospheric agencies. Associated with all, but especially the last, 
there are gravels, sands, with brick and “book” clays, or, under cer- 
tain circumstances, marls. These occur sometimes above, sometimes 
below, but more often in different intermediate positions, while in 
general the relative positions of these different drifts are supposed 
to indicate their relative ages. This, however, appears to me to 
be “not proven,” as the facts observed by Clarence King on the 
Western Pacific slopes, and by Hayes and others in Arctic and 
Alpine regions, combined with what can be studied as taking place 
at the present day in Great Britain and Ireland, would suggest 
otherwise. 

Prior, however, to going further into these subjects, we may 
give a résumé of the principal sections in Ireland that are said to 
afford conclusive evidence of there having been upper and lower 
glacial drifts, with ‘‘middle gravels” of an intermediate age be- 
tween them. , 


208 Scientific Proceedings, Royal Dublin Society. 


There are, indeed, in the neighbourhood. of different groups of 
hills two distinct varieties of boulder-clay, viz. ti// below, and 
moraine drift above; but although in general there is a line of 
boundary between, yet they are rarely separated by aqueous de- 
posits; while if they are so, the latter usually consist of from a few 
inches to a few feet in thickness of fine sand or finely laminated 
clay (book clay); and in such places there is nearly always a “lin- 
ing”’ or rude stratification in the overlying moraine drift, as if it 
had been finally arranged in water—or as if it had slipped down 
from a higher level in the state of mud, or of mud and ice-slush 
mixed together. In many places the latter is suggested, as on the 
low, flattish ground this lining may be very conspicuous; while as 
we ascend to the higher sloping ground all traces of this stratifica- 
cation gradually disappear.' In no place, however, have I seen 
regular continuous sands and gravels between these upper and 
lower glacial drifts; although in places, more especially along 
some of the sea cliffs, there are miles of sections exposed. 

The section which appears to be most relied on as a proof of 
the existence of these “middle gravels”’ in Ireland is that at the 
Kilkenny marble quarry. Here, however, the upper member is 
not a true glacial drift, but a very typical estuarine accumulation— 
one common in the deep-seated Irish river-valleys, having in it 
many striated fragments, but all more or less water-worn, while it 
is similar to drift now accumulating in different long, narrow 
estuaries. In some of these recent estuarine accumulations I have 
found over 50 per cent. of these striated fragments. 

In various places along the coast from Killiney to Bray, both in 
the railway cuttings and “the cliff sections, it is quite evident that 
the gravels, brick-clays, &c., were deposited at the base of a boul- 
der-clay cliff, which at times slipped down and covered them, 
thereby causing glacialoid drift to dovetail and merge into 
gravels, sands, and clays. 

More or less similar phenomena can be seen in the coast cliffs 
of Wicklow, Wexford, Waterford, Louth, Down, Antrim, &c., 
and inland in numerous places. Inland, especially in the Co. 
Tyrone, the gravel is often found surrounding glacial drift-hills, 


1 As has been pointed out elsewhere, on the N. W., or Carlow, slopes of Mount 
Leinster, there is a lined glacialoid moraine drift that now extends out on to a recent 
peat bog (“Geology of Ireland,”’ p. 236). 


G. A. Kinanan—On Boulder-clays and their Gravels. 209 


but in such cases never extending through them, as is proved by the 
railway cuttings. A very instructive case occurs at Redhill, to the 
west of Boyle, Co. Roscommon, and is described in the Geological 
Survey Memoirs by Mr. Cruise. 

In some places, as in the vicinity of Pomeroy, Co. Tyrone, an 
angular, shingly drift has been called “ upper boulder-clay,”’ 
although there is not a particle of evidence to suggest a glacial 
origin; while elsewhere high level gravels, as on Slieve Gallion 
Carn, Co. Londonderry, are said to be of the same age as the 
gravels of the low neighbouring plains, and as they are under 
glacial or glacialoid drifts, are said to prove that the latter are 
those so-called “middle gravels”; although it must be evident to 
anyone who examines them thoroughly, and carefully considers 
the subject, that the higher gravels must be quite distinct, and 
are probably older than the lower ones. 

The result of many years’ minute examination and considera- 
tion of the drift accumulations in various places in the United 
Kingdom, combined with a study of the published descriptions of 
drift sections by numerors observers there and elsewhere, would 
lead me to suggest— 


First—That some of the gravels and other stratified drifts 
under glacial drifts may be younger than the overlying deposits. 

Second—That many of the sands and gravels in the till and 
moraine driits are probably younger than the materials now lying 
over them; and 

Third—That gravels, sands, and other stratified drifts contem- 
poraneous with the allied glacialoid drift, must in general be 
younger than the associated glacial drifts; the exceptions being 
few and rare. 


As to the first : in certain places the till or moraine‘drifts may 
have accumulated over deposits of gravel or such like; but in other 
places it seems highly probable that the gravels now found under 
them were due to the water formed in the ice before and during 
its final melting, producing streams under the glacial drift, thereby 
washing portions of it into gravels and sands. This is specially 
suggested by finding boulders in places in these accumulations, 
while the stratification is distorted as if by currents curling round 
the boulders, or by the roof falling in; also, many of those who 


210 Scientific Proceedings, Royal Dublin Society. 


have studied “live ice”? mention the streams that flow from be- 
neath the glaciers and ice-sheets. 

As to the second: Clarence King and others who have studied 
the dying-out of ice-sheets have found that the ice melts from 
above and below, leaving to the last patches and cakes on different 
- horizons. The waters due to such cakes, when they finally melt 
away, must wash portions of the glacial drift into sands and gra- 
vels formed and arranged subsequently to the overlying drift. 

Similarly in the till and moraine drifts we find on different 
horizons, cakes and patches of gravel and sand, often very irregu- 
larly stratified, as if there was a curling current, or that the roof 
and sides of the cavities fellin, as the cakes of ice gradually melted 
away. In various Papers on the English and Scotch drift such 
cakes and patches of sand and gravel on different horizons are 
appealed to as proofs of the existence of “middle gravels”’ of 
intermediate age; but, if my theory is correct, they are younger 
than the overlying deposits. Also, if large debacles of glacial 
mud slide down to form the upper drift, the water from the snow- 
slush, or even from the mud alone, should form sands, ‘book 
clays,” and the like, between this soft matter and the harder floor 
beneath.” 

As to the third: gravels and other stratified drifts, when asso- 
ciated with glacialoid drifts, must be younger than the original 
glacial drift with which they are connected ; as the glacialoid drifts 
were formed from the debris of the last, while they are interstrati- 
fied with the first. If the original drift cliff was perpendicular, or 
nearly so, the gravels would accumulate against it, whilst subse- 
quently detritus, composed by weathering from the upper portion 
of the cliff, would cover them up; but if there were periodical falls 
or slips of the cliff, the gravels and glacialoid drifts must in some 
places be more or less interstratified, whilst elsewhere they would 
blend or graduate into one another, as can be seen in numerous 
places along the already-mentioned Irish coast cliffs. 


1 Some of the cakes may be isolated and surrounded by the clay, thus forming 
“‘lough holes’’ like those cut when making the railway under the Phoenix Park, 
Dublin. These lough holes seem to have been filled for the most part with water, 
there being only a little sand. 

2 Tf the floor is a rock surface we find in uneven places small patches of these 
stratified drifts, which apparently were formed subsequently to that over them, as they 
fit the roof of the cavity similar to matter found filling a rock cave. 


aes 


XXVII.—NOTE ON THE COAL DEPOSITS OF THE NORTH- 
WEST TERRITORIES OF CANADA. By GERRARD 
A. KINAHAN. 


[Read, February 18, 1884. ] 


As some doubts are still often expressed in this country of there 
being sufficient fuel in the North-West to supply even the local 
requirements of Manatoba, Assiniboia, and Alberta, a short note 
on the lignite deposits of this region may be of some interest to the 
Members of this Society. 

The formations in which these beds occur are considered by the 
Officers of the Geological Survey of Canada to be of later Cretaceous 
or early Hocene age, and in some cases there is evidence of the lig- 
nites occurring on two distinct geological horizons, very possibly re- 
presenting a period intervening between the Mesozoic and Cainozoic 
of Europe. The lignite-bearing series probably underlies a large 
portion of the prairie lands of the North-West, being concealed by a 
thick covering of drift gravel and alluvium ; its outcropping at the 
surface is generally the result of gentle undulations of the strata 
and subsequent denudation. 

In the eastern portion of the area the fuel is more truly lig- 
nitic; but westward, especially in the folded and compressed strata 
composing the foot-hills of the Rocky Mountains, it more nearly 
approaches in lithological characters true coal. West of the Foot- 
Hills this formation is cut off by an immense fault with a large 
downthrow to the east, beyond which break Paleeozoic limestones 
and quartzites form the precipitous and craggy range of the Rocky 
Mountains. That the lignite-bearing series formerly had a wider 
distribution and covered much of these Paleozoic rocks is evident 
from the fact that, far in in the mountains, a small patch of them 
occurs, resting on the older rocks, which have here been let down 
by a series of faults, thus preserving the overlying series from being 
denuded away. Here the lignite has been converted into a semi- 
anthracitic coal of very excellent quality, free from pyrites and 
slate, and quite undeserving of the name of lignite in any sense 
but that of being of post-carboniferous age. It appears on the 
Devil’s Creek, or north fork of the Bow River, at Cascade Park, 


212 Scientific Proceedings, Royal Dublin Society. 


twenty-five miles from Padmore, and about eighty miles west of 
Calgary, close to the line of the Canadian Pacific Railway. But 
although this valuable deposit, has been known for many years to 
some of the early prospectors of this section of the mountains, it 
was not till last summer that the location was secured, and in the 
Fall active operations for extracting the fuel commenced. 

Along the belt of the Foot Hills, where the strata are more 
folded and indurated than on the plains to the east, the coal seams 
crop out more highly inclined, and the beds are probably often re- 
peated. About twenty-eight miles from Calgary, and ten miles 
east of Morley, an important coal outcrop occurs in these beds; it 
is that of Coal Creek, in the Wildcat Hills, on the Cochran Ranche, 
where the seam appears to be about five feet thick, dipping east, at 
an angle of about 30°, under a series of cream-coloured sandstones. 
Most of the other outcrops in this belt are too far removed from 
the line of railroad or other convenient means of transport to be of 
much economic value at present, but eventually many will probably 
prove important. Dr. G.M. Dawson has recorded several outcrops 
in this district, as that on the Big Cottonwood River, north fork 
of Highwood River, and the north fork of the Old Man’s River, 
near the Crow’s Nest Pass, and on the middle fork in the vicinity of 
the Kootenai Pass; also a thick seam, about ten feet wide, on Mill 
Creek; these two last locations are about forty miles west of Fort 
M‘Leod. On a specimen from an outcrop on the Indian Supply 
Farm, a little further south-east, Mr. Hoffman publishes a report 
and an analysis! which may be quoted :— 


‘Colour, pure black; structure, lamellar; lustre, shining resinous, 
with occasional dull patches; powder, black, the same communicating 
a deep brownish-red colour to a boiling solution of caustic potash. 


‘‘ Anatysis BY Stow AnD Fast Coxine. 


Slow Coking. Fast Coking. 
Hygroscopic water, . : 4 6:26 : 6:26 
Volatile combustible matter, . 29°31 4 31:96 
Fixed carbon, . : : . 55:70 : 53°05 
Ash, 3 : ; ; : 8°73 : 8°73 
100-00 100-00 


1 Chemical Contributions to the Geology of Canada (1880), by Christian Hoffmann, 
F. Inst. Chem. (page 12.) 


G. A. Kinanan—On Coal Deposits in the N. W. of Canada. 218 


“‘ Both slow and fast coking gave a pulverulent coke. The ash had a 
pale reddish-brown colour, and agglutinated slightly at a bright red 
heat.” 


These localities all lie to the south of the Canadian Pacific Rail- 
way, towards the United States boundary ; but to the north many 
other outcroppings also occur in the Edmonton district, one seam, 
twenty feet thick, appearing on the Saskatchewan, above Edmon- 
ton, and another, eight feet thick, on the Pembina River. 

In the vicinity of the railway, on the Bow River, there are two 
important outcrops, near the Blackfoot crossing, and on Crowfoot 
Creek; these locations are about sixty miles east of Calgary and 
one hundred and ten west of Medicine Hat, where the seams vary 
from three to nine feet thick, and dip gently towards the west; 
other outcrops occur on the Red Deer River, which lies to the 
north. The following analyses have been published by Mr. Hoff- 


mann :-— 
BLACKFOOT CROSSING. CROWFOOT CREEK. 


‘Slow Coking. Fast Coking. Slow Coking. Fast Coking, 


Hygroscopic water, : Losi 10°72 11°25 11:25 © 
Volatile combustible matter, . 29-26 82°63 31:98 35°59 
Fixed carbon, : 2 . 46-09 42°72 50°85 47-24. 
Nem ee a an S208 13-93 5-92 5-92 


100:00 100-00 100:00 100°00 
Ratio of volatile combustible 
matter to fixed carbon, = il 3 ies TL 9 ieg3i il 2 1Le& 9) TLS 19833} 


These samples gave a pulverulent coke, and agglutinated slightly 
at a bright-red heat. The coal is of a black colour with a brownish 
tinge, and contains thin films of selenite.: 


1 From these analyses, by fast and slow coking, of the proximate composition of the 
coal we may roughly appreciate its value as a fuel and gas-producing material, though 
the fixed carbon and volatile matter vary cnter se according to the method of coking: 
of course the ash and hygroscopic water are constant under both conditions. ‘‘ Lignites’”’ 
always contain a large percentage of the latter, so that its accurate estimation is of the 
utmost importance. In these samples the hygroscopic water appears to be exceptionally 
low : for lignites generally the average percentage varies from 15 to 25 per cent., and 
in exceptional cases it runs as high as 50 per cent. However, the action of caustic 
potash in the present instance indicates the lignitic character of the fuel. Another 
important point to be determined in estimating the commercial value of lignite is the 
question of weathering. Most of the lignites of the north-west appear to bear the 
weather and transport well, the arid climate and the comparative freedom of the coal 
from unstable pyrites being specially favourable for their nondisintegration. 


SCIEN. PROC. R.D.S.—VOL. TV. PT. V. x 


214 Scientific Proceedings, Royal Dublin Society. 


There is also a large coal district on the South Saskatchewan, 
about Medicine Hat; some of the seams can be seen cropping out 
almost horizonally, on the banks of the river, a few miles above the 
latter place. But probably the most important coal deposit in the 
North-West is that of the ‘Coal Banks,” on the Belly River (one 
of the main tributaries of the South Saskatchewan), twenty-five 
miles east of Fort M‘Leod and about one hundred and twenty miles 
south of Medicine Hat. Here the seam is about nine feet thick, 
and dips at a very low angle to the west. This locality is now 
being actively worked by Sir A. T. Gault. The coal is taken in 
barges and steamers to Medicine Hat; hence it is distributed east 
and west along the line of railway: it is a fine semi-bituminous 
coal, containing a little pyrites, and not unlike some Welsh steam 
coals: it appears to be admirably adapted for steam-engines and 
domestic purposes, and is being used on the locomotives of this sec- 
tion of the railway, and also on the steamers plying between Medi- 
cine Hat and the mines; it produces a very hot fire, and forms 
very little clinker or cinder. 

Besides the localities above mentioned many others are known, 
especially in the district to the north; to the east, on the Souris 
plain, the beds are much more lignitic in character than to the 
west. 


Although it is only quite lately that these coals have been ex-. 


tensively used throughout the country, they have been employed 
to a limited extent, for some time past by the North- West Mounted 
Police and by the pioneers of the district ; yet it seems highly pro- 
bable that, on the development of the mines, and extension of the 
railway, these coals will not only be almost exclusively used through- 
out the territory, but that there will be a large export trade to other 
districts. 


ee a 


eis | 


XXVIII.— THE PHOSPHORITE NODULES OF PODOLIA — 
NOTES BY J. P. O'REILLY, Professor of Mining and 
Mineralogy, Royal College of Science, Ireland. 


[Read, March 17, 1884. } 


Ar a recent Meeting of the Natural Science Section of the Royal 
Dublin Society, Professor Valentine Ball submitted for examination, 
and made some remarks on, specimens of the globular or spherical 
concretions of Phosphorite imported into this country from Podolia, 
in southern Russia. Their singular form, their remarkable size, 
and radiated fibrous structure, excited curiosity and discussion as to 
their origin. Wishing to arrive at some solution of the problem thus 
apparently presented, and assuming that a mineral of this remark- 
able character and of such industrial importance must have under- 
gone chemical investigation and been scientifically noticed, I had 
recourse to the authorities at hand in the College Library, and was 
enabled to get from them a sufficiently detailed account of the 
mineral itself, of the nature of its deposits, and its probable origin. 
At the same time I received, through the kindness of Mr. N. Stad- 
nicki, son of Count Stadnicki, on whose estates in Podolia large 
deposits of this mineral exist, a fine collection of the balls in dif- 
ferent states, which enable me, I consider, to push the question a 
stage further than that arrived at in the memoirs which I am about 
to cite. 

The first notice which I met with was the excellent article on 
Phosphorites, forming one of the parts of the Encyclopédie de 
Chimie de Fremy (tom. v., Ist section, 2"*° partie, p. 89), wherein 
the locality of the deposit is noticed and a summary given of a 
memoir on these phosphorites, by Fr. Schwackhofer, published in 
the Jahrbuch der Kais. Kon. Geolog. Reichsanstalt, 1871, xx1. Band, 
p- 211. This memoir is very complete, and accompanied by plates. 
He opens by explaining that the Silurian formation, which extends 
over a great part of Northern Bukovina and Russian Podolia, is 
mainly represented by compact and highly fossilised limestones 
and clay slates. Directly on these rest regularly stratified beds of 

X2 


216 Scientific Proceedings, Royal Dublin Society. 


chalk—sometimes those containing flints, known in the country by 
the name opoka; sometimes the green sands. 

The silurian slates present two very distinct forms—the one 
large, grained and compact, with rough surfaces, greenish-brown 
colour, giving rise, by splitting, to thick flags; the other, slaty in 
its texture, is composed of thin, even, greasy, lustrous, and friable 
plates of a greenish-black or, more rarely, greenish, colour. This 
latter form is that occurring in Russian Podolia, and is character- 
ised by its greater tendency to weathering, giving rise to more 
rounded outlines of country. The first-mentioned clayslates produce 
in the valley of the Dueister and its confluents very abrupt banks, 
sometimes almost perpendicular. The thickness of these clayslates 
ig of several hundred feet. It is in the greenish-black and thin- 
plated clayslates that the globular phosphorite is exclusively found, 
these beds being, according to Bloede and Barbot, referable to the 
Silurian formation. 

The phosphorite balls are interstratified with these slates, often 
in great quantities. Owing to the tendency to weathering of the 
slates, the balls give rise to secondary deposits, such as the detritus 
heaps of the chalk beds, and are found thus along the banks of 
the Dneister, even far into the river bed. 

The localities marked by the more frequent occurrence of the 
phosphorite balls are situated on the left bank of the Dneister, 
in the zone of country lying between S* Uszica and Mogilew. 
Very fine surface deposits are met with at Zurczewka, Kaljus, and 
Ljadowa. 

The mineralogical characteristic of the Podolian phosphorite is, 
‘hat it occurs, almost without exception, in a spherical or globular 
torm, showing an inner concentric radiated structure. 

The surface is uneven, often foliated, feels greasy, and presents 
a dark-green colour, somewhat like that of fresh cast iron. The 
balls, disengaged from the matrix by erosion, and haying under- 
gone abrasion, present a bright-grey and even surface. 

The diameters vary from 2 cm. to 16-18 cm., generally 5-6 cm. 
The density is from 2°8 to 3. The hardness about that of fluor- 
spar. 

The radiated structure is not in all cases the same: in some 
this structure is more marked towards the periphery, becoming in- 
distinct towards the centre, where it appears compact; the core 


O’Rettty—On the Phosphorite Nodules of Podola. 217 


at the centre being in this case of crystalline foliated calespar of a 
bright-grey or greyish-brown colour, showing generally a star form. 
In others the radiated structure is equally distinct all through, 
and at the centre is found a star-formed hollow space, filled with 
a brown earthy mass. The former generally presents a more 
greyish colour; the latter a very distinctly brown colour. LBe- 
tween the radiating fibres or bands occur various enclosed mine- 
rals, such as calcite and plates of pyrites, little grains of quartzote, 
small quantities of a yellow powder, composed of manganese car- 
bonate, a dark-brown pulverulent mass, which is a mixture of iron 
oxyde and carbonate of iron, and finally an aluminous silicate in 
the form of a white earthy mass. Occasionally particles of galena 
occur sprinkled through the mass. 

Several Tables of Analysis are given, one of which gives in 
constituents the composition of the inner and outer zones of the 
spécimen analysed; another that of the core or kernel; and 
another that of the matrix of the phosphorite, which shows whencu 
the phosphoric acid proceeded. 


I.— ConstITUENTS OF THE OUTER AND INNER ZONE OF A COMPLETELY- 
ALTERED PHosPHORITE Batt or 15 cm. DIAMETER. 


| | 
| | 


| Outer Zone. Inner Zone. 
Tribasic lime phosphate. . : : ‘ 19°70 | 87°61 
Phosphoric acid, Be ot 0:03 | 0-29 
Calcium fluoride, : ; : A , 6°16 | 7:29 
Calcium carbonate, . : : 5 ; 0°68 | 0-61 

| Sesquioxide of iron, . d ‘ : : 2°65 | 1-06 
Manganese hyperoxide, . ‘ : : — | 0°57 
Lime silicate, . F : : : : 0:26 | — 
Soda silicate, . ; : . : : 0:46 — 
Alumina silicate, .  . : : aks 3°99 1:01 

| Silica, ; ; : 4 t : f | 4-54 0°32 

| Organic matter, : : : : ; 1-39 0°79 
Water, . : 5 : : : 5 0°72 | 0:53 

| i 

Total, : : : ; : . | 100-58 100:08 


218 Scientific Proceedings, Royal Dublin Society. 


I].—ConstitvuEnts oF THE Corr, THE MippLE anp OutEeR Zone OF AN 
INCOMPLETELY-ALTERED PuospHoriteE Baut or 15 om. DiAMeEtTER. 


| Outer Zone. |Middle Zone. Core. 
Tribasic lime phosphate, . 4 : . 82°66 83°33 53°70 
Phosphoric acid, p : : ; : 0:03 0:43 0:96 
Calcium fluoride, : : : : ail 6°42 6°85 4-58 
Lime carbonate, : : : : i 1:95 5:27 37°02 
Pyrites, é : . é : . 1:08 — = 
Ferric oxyde, . : : : : : 1:24 1:80 1°35 
Potash silicate, . 4 fen es : : 0°51 0°33 0°24 
| Soda silicate, . : : : : : 0°67 0°44 0°32 
| Alumina silicate, : Z é : : 0°55 — _ 
Silica io Auber eter) h tew ag ae 2°63 0:87 0-25 
Organic matter, ; 3 : : ; 1:60. 0°89 0°78 
Water war nme Rieti etter cee cater es Oy Oss 0-31 
Total, 3 : ‘ i P : 99-91 100-59 99°51 


TIT.—Marrrix or tHE PuospHorttss, SituRIAN Suate Rock or ZUROZEWKA. 


Soluble and Insoluble 
Parts in Hydrochloric Acid 
in Ioo parts. Sum 
Soluble. Insoluble. 

Ferric oxyde, . ; 3 : : : 4°78 1°58 6°35 
Ferrous oxide, . : 5 ; s : 2°70 Traces. 2°70 
Manganese oxyde, . é : : : — = Traces. 
Alumina, . : : ’ : ; F 8°86 12°68 21°54 
Lime, : ; : : ; ; : 1:47 Traces. 1°47 
Magnesia, ; : : ‘ 3 , eal 0:41 1:52 
Potash, . : : ; : 4 : 1:23 1:83 3°06 
So lan ean active woe ET Bae ROE rh 0°21 2°08 2°24 
Silica, F ; : ; t ; j Traces. 55°36 55°36 
Carbonic acid, . : : : ; : 0:42 — 0°42 
Phosphoric acid, 5 i , : ‘ 0:33 — 0°33 
Sulphuric acid, chlorine, fluorine, : : — — Traces. 
Organic matter, : : i : : — 4:06 4:06 
Water, . : : ; ! : ; 1:35 — 1°35 

Total, 6 4 : ; : 22°46 TODD 100°40 

| 


O’Retm1ty—On the Phosphorite Nodules of Podolia. 219 


Schwackhofer details fully and discusses the method of analysis 
followed, and the appropriation of the elements found, to the 
constituents mentioned in the Tables, and shows, from the compa- 
rison of Tables I. and II., that the lime phosphate of the Podolian 
phosphorites stands in pete to the calcium fluoride in exactly 
the same ratio as occurs in apatite, and that therefore we may 
admit that the mode of formation is the same as that of apatite. 
He demonstrates this by a Table. 

He further shows that between the apatite constituent and the 
lime carbonate of the inner bands of the phosphorite there is a con- 
stant ratio, the sum of the two constituents being a constant, as is 
shown in the accompanying Table :— 


I. | II. 
Inner Part. || Middle Part. Core. 
_ Lime phosphate, 3 : 2 ; 94:90 || 90°18 | 58:28 
| Lime carbonate, : : : “ ; 0:68 5:27 37°02 
Totals, : : : : ; A 95-58 * 95°45 95°30 


As regards the surface coating this relation does not hold, on 
account of the presence of incorporated foreign bodies. 

The author then proceeds :—‘‘ From the foregoing data, as to 
the nature of the deposit, mode of occurrence, and chemical con- 
stitution of the phosphorite, sufficient ground is afforded for an- 
swering the question, How have these phosphorites originated 2” 

The opinion received up to then, and put forward by the 
author, had been, that these concretions were originally formed of 
carbonate of lime, which was altered into phosphorite by the phos- 
phoric and fluoric combinations washed out of the slate rocks. 
This opinion he now, to a certain extent, modifies. 

He considers that the material for the formation of the calcite 
concretions (specimens of which he found composed of finely crys- 
talline calcite, with some phosphoric and silicic acid, the calcite 
being always at the core and concentrically formed round the 
centre) was furnished undoubtedly by the chalk marl (opoka), 


220 Scientific Proceedings, Royal Dublin Society. 


which ordinarily overlies the phosphorite deposits in thick beds, or 
the former existence of which is at least proved by the remaining 
flint nodules. 

The washing out of the lime by rain charged with CO’, and 
the passage of the lime carbonate into the underlying beds, is, he 
says, easily explainable, as also the separating out of this bicarbo- 
nate as simple lime carbonate, and the concentric layering of the 
simultaneously formed lime particles around the previously formed 
core, with intervention of a lime silicate as a cement. That the 
process was gradual is shown by the shell-like structure of the con- 
cretions, as also by the apparent crushing of the slates in contact 
with the balls. He further shows that the assumption that ele- 
ments requisite for the transformation of the lime carbonate into 
apatite proceeded from the slate is not a mere guess, but is sus- 
tained by the analyses of the mother rock, wherein phosphoric acid 
in determinable quantity is shown to exist, as also traces of fluo- 
rine. He attributes the clefts in the “ completely infiltrated balls” 
(in which there is no calcite kernel), as also the radiated structure 
of the phosphorite, to a contraction of the matter consequent on the 
metamorphosis of the calcite balls of crystalline granular texture. 
This contraction had for consequence the change of texture from 
finely granular into radiated fibrous; and he enters into an exami- 
nation of the volume ratio between the calcite and subsequent 
apatite. ‘This explanation supposes that the phosphoric acid pene- 
trated the calcite balls from outwards inwards in solution (as acid. 
lime phosphate) ; that thus the tenor in calcium, which for apatite 
is 39°68 per cent., and for calcite 40 per cent., that is, nearly the 
same, remained unchanged during the metamorphosis; and he 
cites experiments to prove this. 

In the main, therefore, Mr. Schwackhofer considers that the 
origin of the nodular phosphorites was the metamorphism of 
nodules of calcite into apatite. But it remains to be shown that 
such calcite nodules are usually to be found in Silurian slate-rocks, 
or that calcite usually occurs in that form: furthermore, that a 
change from a compact texture to a radiated fibrous structure, such 
as is shown by the phosphorite, is admissible in this case, or ex- 
plainable by change of volume and contraction. 

The examination of the samples received from Podolia, through 
Mr. N. Stadnicki, seems to me to point to another and less imme- 


O’Rettty—On the Phosphorite Nodules of Podolia. 221 


diate origin. Amongst those specimens are pieces of balls entirely 
composed of iron pyrites: one of these pieces is distinctly marca- 
site, or liver pyrites, the characteristics of which are so well known. 
Moreover, while pyrites occur in nearly every rock, marcasite is 
more particularly associated with marls and clay beds, and in this 
respect the observation of Mr. C. Méne (C. R. lxiv. 867), cited by 
Dana in his 5th edition, p. 800—that the pyrites of unaltered 
sedimentary beds is mostly marcasite, while that of metamorphic 
rocks is ordinary pyrites—is interesting and to the point. If now 
we consider a bed of clayslate, in which originally marcasite 
nodules were developed, these, by subsequent changes of sea level, 
superposition of chalk-marl beds, and slow infiltration of solutions 
containing carbonic acid and other constituents taken from the 
chalk marls into the underlying slate rock, would undergo trans- 
formations which might result at a certain stage in calcite; and 
then the subsequent changes would be explainable in the way 
pointed out by Mr. Schwackhofer. The examination of a nodule 
of marcasite or liver pyrites undergoing decomposition poiuts to 
this solution, since it shows not merely a radiated fibrous structure 
exactly as that of the phosphorite balls, but also a change of volume 
consequent on the formation of sulphate of iron. This change is an 
increase; the mineral is therefore rent, and presents clefts exactly 
as those occurring at the centre of certain of the nodules of phos- 
phorite. The hollowness of these clefts, or the absence of con- 
tained matter, is easily accounted for, since these clefts would be 
filled by the iron salt, and this would be the last removed, if the 
action proceeded from the periphery towards the centre, and would 
either be replaced by another mineral, if the solution could give 
anything, or would simply be removed by the passage of water. 
There would not, therefore, have been contraction, but rather the 
contrary increase of volume, which precisely rendered the mineral 
more apt to give passage to subsequent infiltration and metamor- 
phism. As to the series of changes having led up to apatite, it 
is presumable that it was more complex than that assumed by 
Schwackhofer, who starts with calcite nodules. 

Starting from marcasite nodules, the clefts would tend to show 
that change to sulphate of iron took place first, and that it was 
complete. It must be borne in mind that these nodules, being 
entirely enveloped by clay more or less plastic, were protected 


222 Scientific Proceedings, Royal Dublin Society. 


from disintegration, and that subsequently the iron was replaced 
by lime, giving rise to gypsum, which could in turn give rise, by 
metamorphism, to calcite, and this to apatite. 

What must be borne in mind in a case like this is, that the 
series of geological changes which took place in the country of the 
deposits must have been closely connected with these pseudomor- 
phisms; and that the fact of the beds having undergone great vari- 
ations of level, with change of pressure, change of temperature, 
change of permeating solutions, both as regards constitution, con- 
centration, temperature, and pressure, the final state and products 
which we examine must be the resultant of all these actions. 

That the pyrites still remaining in the beds are still under- 
going decomposition would seem to be shown by the existence of 
chalybeate springs in the district. How far this would point to a 
stage of change, wherein the sulphur was removed as sulphuretted 
hydrogen, is a question to be discussed. Organic matter is shown 
to exist in the balls, and such organic matter would be highly con- 
ducive to this process of removal. Furthermore, relatively small 
quantities would produce this result if caused to pass continuously 
through the nodules, so that what would finally remain after com- 
plete removal of the sulphur would be seemingly insignificant. 

There is a last remark to be made, from a practical point 
of view, relative to this change of marcasite into apatite: it is, that 
indications of marcasite would pro tanto be possible indications of 
phosphorite deposits, and would therefore serve as a guide for their 
research. 


po ay 


XXIX.—ON THE GENERATIVE AND URINARY DUCTS IN 
CHITONS. By ALFRED C. HADDON, M.A., M.R.1.A., 
Professor of Zoology, Royal College of Science, Ireland. 

(Plates X. and XI.) © 


[Read, April 21, 1884. ] 


Generative Ducts.—There is as a matter of fact nothing 
especially remarkable about the generative organs of Chitons. 
Cuvier (1), Middendorff (2), Von Jhering (6), &c., describe paired 
generative ducts arising from the median unpaired generative gland. 
The oviducts arise, according to Haller (11), in Chiton sicudus and 
Ch. fascicularis from a dilated and folded uterus, which is situated 
at about the hinder third of the ovary on the ventral side. Sedg- 
wick (8) (Oh. discrepans and Ch. cancellatus) does not state whether 
the ducts arise from the dorsal or the ventral side of the generative 
organ. Van Bemmelen (12) mentions that the efferent duct in Ch. 
marmoreus and Ch. marginatus springs from the dorsal side, and my 
own. investigations on various forms agree with the latter statement. 
The ducts take a more or less direct course to the gill-row, and usu- 
ally open near the fourth or fifth gill, counting from the posterior 
end. Hubrecht (10) has confirmed by sections “ the presence of the 
same arrangement in Ch. marginatus.” Sedgwick (8) states that 
“the male duct has a short direct course to its opening; while the 
female duct is much coiled.” This, at all events, is not the uni- 
versal case. According to Sedgwick and Haller (11) the duct curls 
round the upper border of the lateral nerve cord, between it and the 
gill vein, and thus opens to the exterior, internal to the gill-row. 
Dall in a short Paper, published in 1874 (5), states that in 1869 
he had noticed the fact that the ovarian openings are not invariably 
simple apertures. Their position had been previously known, but 
it is not uniform in all Chitons. In some the fenestree are close to 
the anus, and single on each side. In describing the orifices of Ch. 
ruber (Lin.) he says, “The ‘cancellated space,’ noticed by Mr. Kmer- 
ton (as per notice in Ann. Mag. Nat. Hist., Mar., 1874), on each 
side, behind the branchiz, is a fold or groove containing the ova- 


224 Scientific Proceedings, Roya’ Dublin Society. 


rian fenestree (Mr. Dall illustrates his statement with a diagram). 
There were in this specimen three fenestree on each side, but, ac- 
cording to Dr. Carpenter, the number is variable,' Prof. Verrill 
having counted from four to six in some specimens. ‘These fenes- 
tree are more complicated than in most Chitons which I have exa- 
mined, I have never been able to satisfy myself that there is a 
true oviduct (opening externally),’ and it may be that the ova are 
dehiscent in the perivisceral cavity, and may be expelled through 
the fenestrae, as they are through the analogous ‘ oviducts or seg- 
mental organs’ of brachiopods.” 

Dr. Carpenter (4) says, “in the genus Stimpsoniella, as in 
Trachydermon (the genus to which Ch. ruber, albus, cinereus, &e., 
belong), the feeces are expelled through slits close to the caudal lobe, 
one on each side.” It is strange that this able systematic concho- 
logist should have overlooked the anus, and have mistaken the ori- 
fices of the oviducts for openings of the alimentary canal and ova for 
feeces ! 

In another paper Dall(7) states of the following species— 
Ch. (Trachydermon) albus : “ Ovarian openings, single on each side, 
the posterior end of the gill-row passing behind them. The 
oviducts, as in some other species, could not clearly be made out.” 
Ch. marmorea (Fabr.) “ Oviducts not made out. Ovarian open- 
ings simple, and close on each side of and a little behind the anus, 
from which a ridge extends in front of them on each side. But 
there appear also to be two openings in the vicinity of the fourth 
or fifth branchia from the posterior end of the gill-rows, one on 
each side. The contracted condition of the specimens, from the effect 
of the alcohol in which they were preserved, prevented a satisfactory 
confirmation of these appearances.” Oh. submarmorea (Midd.)— 
“Soft parts very similar to last in every respect, except that the 


‘I find that in the Ann. Mag. Nat. Hist., 1874, Dr. P. P. Carpenter says 
(p. 121) :—‘‘ Mr. Emerton first observed a great peculiarity in the animal—that there 
is a cancellated space between the posterior gill and the caudal extremity. Professor 
Verrill observed that in different specimens there were either one, two, or three rows 
of holes on each side. The caudal lobe is generally figured as an anal tube; but in 
T. rubrum (sic) it is an imperforate muscle, working the posterior part of the girdle. 
The feeces were distinctly seen to escape, sometimes on one side, sometimes on the 
other, as it appeared to me, from a slit on each side.”’ 

* This was added in ms. in the copy of the Paper Mr. Dall kindly sent me. 


Happon—On Generative and Urinary Ducts in Chitons. 225 


openings near the anus were absent. The specimen was a male. 
Some of these differences may be sexual: at all events, the subject 
requires investigation from living specimens.” Ch. trifida.— 
‘No ovarian openings could be detected.” Ch. australis.—“ The 
ovarian openings situated close on either margin of the anus.” 
Ch. wossnessenskii (Midd.)—‘“ No distinct oviduct could be ob- 
served.” Ch.imporcata (Carp.)—“No oviduct could be traced though 
the ovary was crowded with eggs.” Ch. vestita (Sow.)—“The ‘ova- 
rian’ openings, bilaterally symmetrical, are situated just behind 
and, as it were, under the shadow of the posterior branchia on each 
side. They are not simple orifices, but fenestrae, composed of two 
openings somewhat oblique and linear; the anterior a little nearer 
the girdle, and a little larger than the posterior one.” Chitonellus 
fasciatus.— There seemed to be two oviducts leading from a single 
ovary to small orifices, one on each side of the anus.” In a few 
other species Dall has identified the normal arrangement stated 
above at the commencement of this Paper. 

I have recapitulated Dall’s statements, in order to show the 
ereat difficulty there is in making out certain details of the inter- 
nal anatomy simply by dissection of spirit-hardened specimens. If 
it had been possible to sectionize these examples, the relations of the 
generative ducts would have been elucidated ; and, for the future, 
it appears to me, we must be cautious in admitting the absence of 
generative ducts in Chitons till we have microscopical evidence to 

‘prove it. 

My own observations on the oviduct of Ch. ruber call for little 
comment. The duct arises on the dorsal wall of the ovary, near 
its posterior end, as a dilated, ciliated, or rather flagellated sack, 
which at first runs parallel to the gland, and then diverges out- 
wardly, narrowing into a circular oviduct, lined with ciliated cubical 
cells, and possessing a large lumen. This pursues a straight course 
outwards, being slightly directed backwards, and ends with tumid 
folded lips, between the foot and the branchial vein, about the level 
of second and third gill, counting from behind. 

The general nature of this duct will be seen on reference to 
figure 1, plate X., which is a camera-lucida drawing combined 
from one or two consecutive sections, and is not an ideal diagram. 
The state of preservation prevents me from adding those histo- 
logical details which I should wish. 


226 Scientific Proceedings, Royal Dublin Society. 


Fenestral Glands. — The above-mentioned “ cancellated 
spaces,” or fenestrae are the expression of somewhat complex glan- 
dular infoldings of the epidermis in those regions, for which I pro- 
pose the provisional name of “ Fenestral glands.” 

Hach “cancellated space” extends, transversely, from that spot 
where the upper surface of the foot joins the body proper outwardly 
as far as the longitudinal fold on the underside of the mantle’ ; 
and longitudinally it extends from just in front of the anus to about 
the region of the renal duct, and therefore some little distance 
behind the generative orifice. The extent of the area and the 
complexity of the gland appear to vary considerably in different 
specimens of the same species.” 

The epidermis of the ventral surface of the foot is composed of 
columnar cells; these become somewhat shorter on its upper surface, 
and in the region in question again become markedly columnar, 
and very large in size. They resume their ordinary character in 
passing over the longitudinal fold; and external to it they secrete 
the calcareous spicules characteristic of the species. 

The gland simply consists of the epidermis, composed of large 
columnar cells of the definite areas above mentioned, which is 
thrown into a number of folds, or produced into slightly contorted 
and branched tubes, thus giving a remarkable labyrinthine appear- 
ance to transverse sections of that region of the body. Between 
the variously cut sections of these tubes are small patches of poly- 
gons which are, of course, merely the transverse or oblique sections 
of the cells or other ceca of the gland. See figures 2-4, 
Plates X. and XI. 

It would be premature at present to discuss the nature of these 
curious infoldings: in the allied Ch. cinereus they appear to be in- 
conspicuous, and to be absent or rudimentary in other forms. 

Dr. Hubrecht (9) has described a pair of simple ceecal glands in 
Proneomenia sluiteri (Ebrcht.) which open into the anal cavity, and 
which secrete extremely delicate threads; anteriorly they are en- 
closed in a strong muscular investment. Hubrecht suggests they 


1 This fold is the ‘‘ fringe’’ or ‘‘ true mantle edge”’ of Dall (7), and the ‘‘ longitu- 
dinal fold’’ or ‘lateral band’’ of Haller (11). 

2 For example, in all my specimens of Ch. rwber from Norway the gland is much 
infolded; but in a specimen from ‘Eastport, N. E. America’’ (for which I am in- 
debted to the courtesy of the Rev. A. M. Norman), the gland is a great deal simpler. 


Happon—On Generative and Urinary Ducts in Chitons. 227 


may be compared with a byssus organ of very primitive construc- 
tion, or may prove to play some accessory function subordinate to 
the secretion of generative materials. 

The same organ, although in a much less developed condition, 
was found by Hubrecht in Neomenia; the muscles, too, are nothing 
like so well developed as in the former genus. 

It is possible that these glands of the Neomenie may be homo- 
logous with the glandsin question. The difference in position need 
prove no difficulty, since it would be only another example of the 
tendency of certain terminal organs in the Amphineura (such as the 
branchie, excretory, and generative ducts) to extend along each 
side of the body. A greater difficulty exists in a comparison of the 
structure of the glands themselves; but this I will leave for the 
present, till I am able to state how they occur in other species of 
Chitons. 

Hidneys and their Wucts.—Until Sedgwick’s investi- 
gation in 1881 (8), our knowledge of the structure and relations of 
the kidneys of the Chitons was of the most unsatisfactory and con- 
tradictory kind possible. 

Middendorfi (2) figures and thus describes, in Ch. stelleri, a 
gland which he identified as the kidney :—“ To the naked eye it 
appears as a very broad velvet-like covering on the shining tendon- 
mass of the ventral muscles; the middle area only of the ventral 
body-wall is left free ; the sides of it, however, and a portion of the 
lateral wall of the body-cavity are covered in the form of a horse- 
shoe ; each limb of this horse-shoe arises close behind the anterior 
diaphragm, proceeds backwards, and unites with its fellow in a 
elosed arch on the front wall of the posterior diaphragm.” The 
gland itself is stated to consist of a longitudinal canal beset with 
ramified ceca. ‘The whole structure is very delicate, and possesses 
extremely thin walls. The Russian naturalist gives no account of 
the histology of the gland, and is careful to add that he was 
unable to discover its external opening or its relation to the other 
viscera. ; 

Schiff (3) could not find this gland in Ch. piceus, and throws 
doubt upon Middendorff’s interpretation.’ 


1 [ have roughly dissected a Ch. piceus from the Barbadoes, and haye secn the 
kidney, but I have not yet made out its relations.—A. C. H. 


228 Scientific Proceedings, Royal Dublin Society. 


Von Jhering (6) assumes that Schiff has demolished Midden- 
dorff’s account, and asserts that ‘‘ a kidney was unknown in Chiton 
until now.” He thus defines the newly-discovered (!) organ: “ The 
kidney is a tree-like ramified gland, lined with a ciliated epithelium, 
lying upon the floor of the body-cavity ; it possesses an unpaired 
median efferent duct, which opens below the anus.” The form dis- 
sected was Ch. fascicudaris. Mr. W. H. Dall informs me that, in a 
letter to him, Von Jhering writes that the posterior median opening 
of the kidney was an error of observation on his part; and Hu- 
brecht (10)-states that “Dr. Brock, of Gottingen, kindly writes to 
tell me that Von Jhering has lately withdrawn this view, as repos- 
ing on an erroneous observation, and has been convinced of the 
presence of lateral renal openings (prior to Sedgwick’s exhaustive 
researches).”” Dall(7) “did not detect the renal organ in some cases, 
and failed to find any excretory opening.” He goes on to say, “ It 
is probable that this exists, but the contraction of the tissues of my 
specimens by alcohol may have obliterated it.”’ 

Sedgwick (8), in a preliminary Paper,’ entirely and successfully 
disproves Von Jhering’s statements, and found that ‘“‘ Middendorff’s 
observations, as far as they went, were perfectly correct.’ The spe- 
cies he examined were Ch. discrepans and Ch. cancellatus ; the former 
species being so closely allied to Oh. fasciculatus that it practically 
amounts to re-examination of Von Jhering’s species. The kidney is 
a paired dendritic gland (figs. 1 and 2),’ with an external opening 
into the pallial groove, and an internal pericardial orifice ; it lies on 
the side of the floor of the body cavity. Hach gland consists of a 
longitudinal duct, beset with branched glandular ceeca; about the 
level of the last six gills this duct is swollen into a “ bladder-like 
structure,’ which, at its posterior end, sends out a small tube, and 
at right angles to itself, which opens to the exterior in the pallial 
row, and the level of the last (16th) gill. About the level of the 
fourth shell-plate there is a second tube, which turns sharply round, _ 
and runs back more or less parallel with, but above and internal to, 
the former. It is at first also furnished with glandular ceeca, but 


1 I understand that he is not intending, for the present at all events, to continue 
his investigations. 

* T am enabled through the kindness of my friend Mr. Sedgwick, and by the per- 
mission of the Royal Society, to introduce Mr. Sedgwick’s original diagrams (Figs. 1 
and 2) in illustration of his views. 


Happon— On Generative and Urinary Ducts in Chitons. 229 


IME, Io 


A diagrammatic representation of the kidney and generative ducts of Chiton dis- 
erepans, viewed from the ventral surface. The branched nature of the kidney is shown 
in the anterior part of the figure on the right side; posteriorly these secreting tubules 
are omitted. On the left side of the figure the kidney duct alone is indicated. 

a, anus; br., the 16 branchize ; D, dilated part of kidney duct opening to exterior ; 
g, generative gland, the greater portion of which is removed: g.d., generative duct ; 
g.0., generative orifice; h.k., posterior part of kidney duct ; #.t., secreting tubules of 
kidney ; &.d., duct of kidney running forward, bending round at T and running back, 
receiving glands as far back as O: from O it runs to the pericardial opening p.o., re- 
ceiving no glands; y.g., pallial groove; 7.0., renal orifice; 13, 14, 15, 16, last four 
gills ; the ventricle and auricular openings are indicated by dotted lines. 


SCIEN. PROC. R.D.S.—VOL. IY. PART Y. % 


230 Scientific Proceedings, Royal Dublin Society. 


from the level of the fifth shell-plate to its posterior termination it 
is devoid of them. On reaching the hinder border of the bladder- 
like dilation of the kidney duct first described, it runs outwards and 
then forwards, in close contact with the dorsal side of the lateral 
nerve cord. At the level of the penultimate gill it opens by a small 
pore into the pericardium, beneath the anterior part of the auricle. 


A diagrammatic representation of a transverse section through Chiton discrepans 
at the level of the renal orifices. The dorsally situated pericardial cavity is separated 
from the general body cavity by the pericardial floor. The posterior, apparently 
median unpaired part of the kidney, seen by von Jhering, lies on the floor of the 
general body cavity. A little in front of this section the kidney tubules take up a 
distinctly lateral position. 

D, p.g., b.r., k.t., r.0., asin Fig. 1; A, auricle; A.C., alimentary cae b.a., 
branchial artery; 4.v., branchial vein; 6.c., body cavity ; F, foot; g.g., generative 
gland; £.¢., opening of kidney tubules into dilated part of kidney duct; J. n., lateral 
nerve cord; p.x., pedal nerve cord; p.c., pericardium; p..d., part of kidney duct 
which is hidden from view by D in Fig. 1; V, ventricle. 


The recurrent internal kidney duct, which receives no glandular 
ezeca, is, with the exception of a small portion adjoining the peri- 
cardial opening, lined by columnar cells containing a brownish- 
yellow colouring matter, which renders this portion of the duct 
easily visible to the naked eye. The part of the duct which runs 
forwards from the level of the hinder edge of the bladder to the 


Happon—On Generative and Urinary Ducts iu Chitons. 


231 


pericardial opening is lined with large columnar cells, which line 


also the pericardial opening. 


Haller (11) refers to the great difficulty in the study of this 
organ on account of its colour and delicacy. He finds that in the 
two species he examined (Ch. stcudus and Ch. cajetanus), the sulphur- 


yellow-coloured kidneys are paired acinose glands (fig. 3).! 


find on each side a wider portion, 
which we will call the kidney- 
body (‘ Nierenkérper’), and which 
is in reality nothing more than a 
wide tube into which the more 
or less compound flaps open se- 
parately. It extends from the 
hinder end of the first ‘shell- 
scale’ to about the middle of 
the last; the flaps opening into 
the kidney-body throughout its 
length.” ‘These flaps may be di- 
vided into two groups—the longer 
and shorter. ‘The latter densely 
beset the anterior portion of the 
kidney-body on all sides; in the 
hinder region, however, the upper 
surface is nearly free from them. 
The larger flaps, which are very 
long, are only slightly ramified ; 
they are grouped separately at 
fairly constant points, and only 


open mesially, and on the under 


side of the kidney-body, except 
at the hinder end. These long 
flaps are arranged in eight brush- 
like groups, corresponding to the 
hinder border of each shell. The 
flaps of one side often overlap 


“We 


) 
i 


t 1 


Zz 


Fic. 3. 


Dissection of the renal organs (nephridia 
of Chzton stculus, after Haller (11). /, foot ; 
ZL, edge of the mantle not removed in the 
front part of the specimen; s.0., cesophagus ; 
af, anus; gg, genital duct; go, external 
opening of the same; eg, stem of the nephri- 
dium leading to zo, its external aperture; 
nk, reflected portion of the nephridial stem; 
ng, fine czeca of the nephridium, which are 
seen ramifying transversely over the whole 


inner surface of the pedal muscular mass. 


1 Fig. 3 is reproduced, by permission of the publishers, from Fig. 15 of Professor 
E. Ray Lankester’s article ‘‘ Mollusca,’’ in the last edition of the Hneyclopedia 


Britannica. 


2032 Scientific Proceedings, Royal Dublin Society. 


those of the other across the median ventral line; but there is 
never any structural junction. 

The kidney-body itself lies in the lateral body-wall, and in its 
histological and physiological structure it agrees with that of the 
flaps. Our author, however, denies that the efferent duct arises 
from the posterior enlargement of the kidney-body. In a foot- 
note he adds :—“ In transverse sections a small forwardly-projecting 
diverticulum of the terminal kidney duct can be seen (Nierenend- 
gang), which is, however, separated from the pericardium by thick 
musculature, and always appears as a short blind process.” 

A duct from the kidney (Nierengang) arises behind the fourth 
tuft, runs backwardly mesial to the glandular body, at first under 
the generative organ and further behind under the pericardium to 
about the middle of the enlargement of the kidney-body .Some- 
what before the ventricular end of the heart it suddenly bends 
outwards, and passing over the kidney-body and above the lateral 
nerve, but below the gill vein, opens externally between the 
fourth and fifth gills counting from behind. This duct, which he 
calls the kidney-duct (Nierengang), is constructed like the kidney, 
and even some of the kidney-flaps open into it anteriorly. It at 
once strikes the eye as often appearing injected with the brown 
secretion of the kidney. “The brown colour ceases at the spot 
where the duct suddenly turns outwards; and then one could 
imagine, if one is predisposed, that there is an opening of the 
kidney into the pericardium in Chitons.”’ This terminal portion 
of the kidney is histiologically very different from the kidney, and 
also from the other portions of the efferent duct. The latter is 
lined with a low cubical ciliated glandular epithelium. ‘The for- 
mer, however, close to its opening into the brown-coloured portion, 
has a three-fold higher cylindrical ephithelium, with flagella four 
or five times the length of the cells. The height of these cells 
diminishes gradually towards the exterior, but ends abruptly in a 
wall-like manner where the efferent duct enters the kidney duct. 

‘‘The internal opening of the kidney, possibly into the peri- 
cardium, as occurs in other Gasteropods, does not exist. We must 
rather assume that, until some one shall have described the de- 
velopment, an internal opening, or ciliated funnel, existed in late 
larval stages, which in the adult animals has entirely closed, and 

has so far been metamorphosed that it is no longer recognizable. 


Happon—On Generative and Urinary Ducts in Chitons. 233 


I have the verbal information of Dr. B. Hatschek that this is not 
unique of its kind, since the ciliated funnel of Sipunculus exists at 
first, and is degenerated in a later larval stage.” 

Van Bemmelen (12), in order to test the above results, studied 
Ch.marmoreus (Fabr.), Ch. marginatus, and Chitonellus fasciatus, and 
found, “with all desirable clearness, the opening of the kidney into 
the pericardium, described by Mr. Sedgwick,” and confirms the 
latter’s account of the general structure of the kidney, and neces- 
sarily at the same time casts doubt upon Haller’s interpretation. 
He believes that Haller has confused the external duct with the 
pericardial duct. The latter holds that the terminal portion of 
the kidney duct, directly it turns at right angles to lead to the ex- 
terior, is lined with flagellate cells, which very shortly pass into the 
ciliated cubical cells which line the remainder of the efferent duct. 
Van Bemmelen suggests that the flagellate portion arising from the 
kidney-duct opens into the pericardium; and that the ciliated duct, 
which certainly opens to the exterior, arises from the kidney-body 
and not from the kidney-duct, as Sedgwick had previously stated. 
Van Bemmelen concludes by saying :—“ Although Dr. Haller and 
I have not examined the same species as Mr. Sedgwick, yet I am 
disposed to believe that the differences between his description and 
that of Mr. Sedgwick’s and my own are not referable to variations 
of the species.” 

In reply to this criticism, Haller (13) states that he does not 
deny that the pericardial orifice may occur in some Chitons, and 
might naturally be expected to occur in Chitonellus, and in those 
Chitons which have a short row of gills, but that it does not occur 
in his species, though it may do so in Sedgwick’s and Van Bemme- 
len’s. He maintains the correctness of his former interpretation, 
and recalls the small blind diverticulum from the terminal kidney 
duct (Nierenendgang), and says: “I now believe that in this di- 
verticulum is to be seen the rudiment of a former ancient opening 
(ciliated funnel, ‘Wimpertrichter’) into the pericardium in Ch. 
siculus and Ch. fascicularis, which opening, according to the state- 
ments of A. Sedgwick and Dr. Van Bemmelen, is said to be found in 
other forms ”’ (I may add, though he does not refer to the fact, that 
in Haller’s figure 36 (11) this diverticulum (7) is ciliated). Haller 
clearly suggests that a pericardial duct, where it exists, opens into 
the terminal portion of the kidney duct immediately before the 


234 Scientific Proceedings, Royal Dublin Society. 


latter opens to the exterior—a position which is certainly at vari- 
ance with the normal arrangement in molluscan or other excretory 
organs. 

I have made at least two series of transverse sections through 
Trachydermon ruber (Linn.), from Norway,’ and find that they cor- 
roborate Sedgwick’s account in every essential point. 

An examination of Plate X., figures 5-8, will render the sub- 
ject quite clear. These are consecutive sections, one side of the 
animal only being drawn. I should add that the sections are a little 
oblique. Owing to the animals not being well preserved, I am 
unable to give histological details; but, in both the animals, the — 
histological characters of the internal and external ducts are suf- 
ficiently well marked to prevent any mistake. 

In figure 5 we have a section of the recurrent or pericardial 
duct of the kidney (p. d.) attached to the ventral wall of the peri- 
cardium ; and external to this is the large thin-walled kidney- 
body (k. 0.), the “ bladder-like structure” of Sedgwick, with its 
glandular ceca on the lateral wall of the pericardial chamber ; and 
opening into it is the cut end of a ciliated tube (7. p. d.). In the 
succeeding sections (Plate XI., figures 6, 7) this tube is seen to 
pass into the pericardial duct of the kidney, and is, in fact, a special 
recurved portion of that duct. 

On the other hand, figures 7, 8, and the succeeding two sections, 
show the kidney-body passing outwardly through the muscular 
wall of the body, and curving over the lateral nerve-cord and 
below the branchial vein, eventually to open on the exterior mesial 
to the gill row. 

The pericardial orifice of the kidney opens about the level of 
the outer communication of the auricles with the ventricle ; and 
the external aperture is only a short distance posterior to it. 

At present the case stands thus: Sedgwick says that there is a 
pericardial orifice in Oh. discrepans and Ch. cancellatus. Haller 
denies it in Ch. siculus (Gray) and Ch. cajetanus. Van Bemmelen 
has found it in Ch. marmoreus (Fabr.), Ch. marginatus, and Chitonel- 
lus fasciatus. I now describe it in Ch. ruber (Linn.). From indica- 


1 These specimens of Ch. ruber from the Natural History Museum were collected by 
P. Chr. Asbjérnsen of Norway, and were kindly placed at my disposal by my friend 
Mr. A. G. More, the Curator of the Museum. 


Happon—On Generative and Urinary Ducts in Chitons. 235 


tions in an imperfect series of Ch. cinereus (Linn.), I feel confident 
that it occurs in that form. And, lastly, I have seen it in Ch. 
longicymba (De Blainv.). The latter is one of the species collected 
by the “ Challenger’? Expedition. In my forthcoming Report on 
the anatomy of the group, which will be published by the ‘“ Chal- 
lenger’’ Commission, I hope to be able to elucidate this and other 
points in the anatomy of this interesting group, by the examina- 
tion of a larger range of forms than has as yet fallen to the lot 
of any naturalist ; and till then I will not attempt any generaliza- 
tions. 

In the foregoing Paper I have simply spoken of the species 
referred to as belonging to the genus “Chiton.” I now append 
a list of the genera, adopting the nomenclature which is in most 
general use :— 


Leptochiton cancellatus, Sow. 
a marginatus, Penn. 
Trachydermon ruber, Linn. 
i albus, Linn. 

x cinereus, Linn. 
Tonicella marmorea, Fabr. 
bes submarmorea, Midd. 

Ischnochiton longicymba, de Blainy. 

Ischnoradsia trifida, Carp. 

Lepidopleurus cajetanus, Poli. 
Lepidoradsia australis, Sow. 
Chiton siculus, Gray. 
Acanthopleura picea, Gmel. 
Mopalia wossnessenskt, Midd. 


Placiphorella imporcata, — Carp. 
Acanthochiton discrepans, Brown. 
a fascicularis, Poli. 
Cryptochiton stellert, Midd. 
Chitonellus larveformis, de Blainyv. (= Chl. fasciatus, Quoy et 
Gaim). 


236 


The 


10. 


1a 


12. 


13. 


Scientific Proceedings, Royal Dublin Society. 


LIST OF REFERENCES. 


G. Cuvrer.—‘‘ Mémoires pour servir 4 Vhistoire et 4 Vanatomie 
des Mollusques.”’ 


. A. Tu. von Muppenporrr.— Malaco-zoologica rossica I. Beschrei- _ 
bung und Anatomie neuer Chitonen,” &¢.—Mémoires de 
l’Acad. Imp. des Sci. de St. Pétersbourg. 6™° série, sc. 
nat., t. vi., 1849, p. 67. 

. M. Scurrr.—“ Beitrige zur Anatomie von Chiton piceus.”— 


Zeitschr. f. wiss. Zoologie, Bd. m., p. 12. 1858. 


. P. P. Carpenter.— ‘On the Generic Affinities of the New-England 


Chitons.”—Ann. and Mag. Nat. Hist. 1874, p. 119. 


. W. H. Datu.—< Notes on an Examination of Four Species of 
Chitons, with reference to Posterior Orifices.’’— Bull. 
Kssex Instit., vi. August, 1874. 

. H. von Juerinc.—‘ Beitrige zur Kenntniss der Anatomie von 
Chiton.”—Morph. Jahrb. 1v. 1878, p. 128. 

. W. H. Datit.—* Scientific Results of the Exploration of Alaska : 


Report on the Limpets and Chitons of the Alaskan and 
Arctic Regions.” — Proceedings of the United States’ 
National Museum, vol. i. December, 1878, p. 63. 


. A. Sepewick.—‘‘ On certain Points in the Anatomy of Chiton.”— 


Proc. Roy. Soc. 1881, p. 121. 


. A. A. W. Huprecut.—‘ Proneomenia sluiterit, gen. et sp. n., with 


Remarks upon the Anatomy and Histology of the Amphi- 
neura.’’ — Niederlindisches Archiv fir Zoologie, Suppl. 
Band. 1881. 


A. A. W. Husrecut.—* A Contribution to the Morphology of the 
Amphineura.”’— Quart. Journ. of Microscopical Science. 
April, 1882, p. 212. 


B. Hatter. —‘‘ Die Organisation der Chitonen der Adria.” — 
Arbeit. des Zool. Instit. zu Wien, 1882, 1v., p. 323. 


J. F. van Bemmeten.—‘‘ Zur Anatomie der Chitonen.’”’—Zoolog. 
Anzeiger, 1883, No. 142. 


B. Hatter. —‘ Bemerkungen zu Dr. J. F. van Bemmelen’s 
Artikel: ‘Zur Anatomie der Chitonen.’’’ — Zoolog. 
Anzeiger, 1883, No. 149, p. 509. 


Happon—On Generative and Urinary Ducts of Chitons. 287 


EXPLANATION OF PLATES X. AND XI. 


All the figures are from spirit-preserved specimens of Chiton 
(Trachydermon) ruber (Linn.), and are drawn to the same scale, 7. e. 
about 28 diameters. 


Ao., aorta. au., auricle. 6.a., branchial artery. Obr., gill. 0. v., 
branchial vein. c., commissure of pedal nerve cord. e. d., external 
duct of the body of the kidney. /t., foot. gl., fenestral gland. int., 
intestine. k.b., body of the kidney. JU. f., longitudinal fold of the 
mantle. l.n.c., lateral nerve cord. m., mantle. od., oviduct. opng., 
opening of the kidney into the pericardium. ov., ovary. 0. ow., 
external orifice of oviduct. pc., pericardium. p.d., pericardial or recur- 
rent duct of the kidney. p.n.c., pedal nerve cord. p. v., pedal blood- 
vessel. pv. ¢., perivisceral cavity. 7., rectum. 1. p.d., recurved portion 
of pericardial duct of the kidney. v., cavity caused by the decalcifi- 
cation of an anterior sutural lamina of the succeeding valve. 


Plate X., Fig. 1.—Transverse section of body in region of the ovi- 
duct, giving a longitudinal section of the latter (combined from three 
consecutive sections). 

Figs. 2, 3, and 4.—Transverse sections of another specimen at the 
posterior end of the body, in the region of the ‘ fenestral gland,”’ of 
which 2 is the most anterier, and 8 the most posterior. Notice the 
complexity of the infoldings of the gland ; the scattered groups of poly- 
gons are transverse sections of other portions of the gland. In Fig. 2 
the auricles (au) are seen; in Fig. 8 they fuse together; and in Fig. 4 
their posterior wall is just seen. The pedal nerve cords are seen to 
gradually dwindle away posteriorly. 


Plate XI., Figs. 5, 6, 7.—Portion of transverse sections in region of 
the kidney-ducts of same specimen as Fig. 1, showing the opening of 
the pericardial duct into the pericardium, and the external duct of the 
kidney-body. 

Fig. 8.—Diagram to show the relations of the urinary ducts. 


SCIENC. PROC. R.D.S.— VOL. IV., PART V. Z 


(2380 al 


XXX.—ON THE ORIGIN OF FRESHWATER FAUNAS: A STUDY 
IN EVOLUTION. By W.J.SOLLAS, M.A., D.8c., F.G.S., 
Professor of Geology and Mineralogy in the University of 
Dublin. (Abstract) 


[Read, May 19, 1884. ] 


Tur poverty of freshwater faunas as compared with marine is 
commonly attributed to a supposed inadaptability on the part of 
marine organisms to existence in fresh water. That this explana- 
tion is altogether inadequate is shown by the existence of fresh- 
water jelly-fish such as Limnocodium, and still more directly by 
the experiments of Beudant, who succeeded in accustoming several 
kinds of marine mollusca to a freshwater habitat. The view of 
Von Martens is, that the severity of a freshwater climate is pro- 
hibitive of the existence of most marine forms in rivers, and espe- 
cially in the rivers of temperate regions. This cause, though no 
doubt efficient, is not altogether sufficient, and a more thorough- 
going explanation is necessary. This is chiefly to be found in a 
study of the means by which a wide distribution of marine animals 
is secured. In the case of stationary forms this is accomplished 
by means of free-swimming embryos, and as these are transported 
by currents, they can never pass from the sea into rivers, in which 
the current is always directed seawards. Nor, probably, could an 
attached form once introduced into a river permanently establish 
itself so long as its propagation took place exclusively through 
free-swimming larvee, for these would gradually be borne out to sea. 
Hence, freshwater animals should not, as a rule, pass through a 
free larval stage of existence, nor as a matter of fact do they. In 
the Hydra, freshwater Sponges, and ;Polyzoa, the young usually 
emerge from a horny cyst in the complete state. In the Unio- 
nidee, the glochidium stage provides for a distribution, in which a 
journey invariably seawards is not involved. 

Paiudina is viviparous, and as in the case of other freshwater 
molluscs, the young do not enter upon a free existence till they are 
essentially similar in their mode of movement to their parents. 


Sortas—On the Origin of Freshwater Faunas. 239 


The suppression of a free-swimming larval stage is not only met 
with in freshwater animals, but is frequent with many marine in- 
vertebrates. This is connected with the fact that the larval stage 
is in a position of disadvantage as compared with the adult. On 
the doctrine of evolution, the more complex structure of the adult 
animal implies this. Hence there isan advantage to the organism 
if the larval stage can be passed over, withdrawn as far as possible 
from the chances of the environment, in a state of seclusion. From 
this various other modifications follow; development in seclusion 
necessarily involves a supply of easily accessible food, hence the ap- 
pearance of yelk and other kinds of nourishment furnished by the 
parent to the imprisoned embryo. Again, the energy of the larva 
being economized in various directions (it is spared the drudgery 
of working for its own existence, and is supplied with nutriment 
in a form that makes the least demands on its digestive powers, a 
larger balance remains available for metamorphic changes. Thus 
arise the phenomena of accelerated and abbreviated development. 
Further, the shortening of the larval life probably leads to the 
lengthening of the adult life, and shifts the chances of variation 
and selection forwards into the adult stage. Thus animals which 
hatch out in a complete state will most probably suffer modifica- 
tions of that state, and not of previous ones, except very indirectly. 
Here we discover a direct tendency towards a mode of develop- 
ment which explains the “arborescent” character of our most 
natural methods of classification, 7.e. the tendency of the tree of life 
is now to produce leaves rather than new branches. In the case of 
freshwater fauna very direct reasons have existed for the suppres- 
sion of the free larval stage. These are to be found in the severity 
of the climate and the dangerous direction of the river current. In 
connexion with the suppression of the larval stage may be noticed - 
the richness in species and the poverty in genera of the freshwater 
mollusca. 

In discussing the origin of freshwater fauna, there are three 
hypotheses from which we have to select: 1, that marine forms 
have migrated directly into rivers; 2, that they have first become 
adapted to existence in marshes, and subsequently have entered 
rivers ; and 3, that marine areas have been converted into fresh- 
water ones. ‘The last holds most frequently, especially in the case 
of attached non-locomotor forms. Hence the origin of freshwater 


240 Proceedings of the Royal Dublin Society. 


animals (invertebrates) is connected with the great movements 
which have affected the earth’s crust. The earliest well-known 
lacustrine areas are those of the Old Red Sandstone, the direct de- 
scendants of the preceding Silurian seas. In the deposits of one 
of these lakes we meet with the earliest known freshwater mollusc, 
Anodonta jukesti (Korbes). Probably, considering the remoteness 
of the alliance of Lymnea to existing marine genera, it also, 
and, perhaps, Valvata with it, originated at the same time as 
Anodonta. 

The lakes of the Permo-Triassic period, the residues of car- 
boniferous seas, produced considerable additions to the freshwater 
fauna of the globe. The Neritide and Cerithiade are probably 
post-Paleeozoic families, and as the Neritide and Melaniide are 
so closely connected with them, they may be regarded as col- 
lateral, or more probably direct descendants, and thus may have 
originated in Triassic lakes, but not earlier. Other genera pro- 
bably arose at the same time; the occurrence in Cretaceous deposits 
of Unio, Physa, Valvata, and Lymnea in the Nearctic, Paleearctic, 
and Oriental regions, suggest a high antiquity for these genera; 
but they may have existed, as we have suggested, in Paleeozoic 
times. 

The lakes of the Tertiary period furnished probably further 
contributions to our freshwater fauna, such as Lithoglyphus and 
Dreissena. Thus, existing freshwater genera are probably descended 
from marine forms which became metamorphosed in the waters of 
the Devonian, Triassic, and Tertiary lakes. In the lakes of Central 
Africa the tertiary freshwater fauna still survives; nearly all of 
the genera from Lake Tanganyka, described by Edgar Smith, 
being referable to genera already in existence in Mesozoic and 
VYertiary times. The lakes of the Northern Hemisphere received, 
on subsiding beneath the glacial sea, such arctic forms as Lysis 
relicta and Pontoporeia affinis, but most of their existing inhabitants 
have re-entered them, since their emergence from the sea, from 
their tributary rivers, or the rivers of adjacent regions. 


peel. 


XXXI.—ON THE ACTION OF WAVES ON SEA-BEACHES AND 
SEA-BOTTOMS. By ARTHUR ROOPE HUNT, M.A., 


[ Read, March 17, 1884. ] 


THE action of waves on sea-beaches and sea-bottoms has been 
much discussed during the last fifty years, but apparently without 
much practical result, as there is scarcely an important point con- 
nected with the subject that is accepted without dispute, whilst not 
only the opinions, but even the recorded observations, of skilled 
observers are often, to all appearance, in hopeless conflict, 

Current scientific opinion on this question may be conveniently 
gathered from three valuable Papers! published in the Proceedings 
of the Institution of Civil Engineers, viz. :— 

* “On the Alluvial Formations and Local Changes of the South 
Coast of England,” by John Baldry Redman, M. Inst. C. H.— 
Proc: Inst. C. E., vol. xi: 

* “ Description of the Chesil Bank, &c.,”” by John Coode, M. Inst. 
C. E.—Proec. Inst. C. E., vol. xii. 

* « On the Origin of the Chesil Bank, &ec.,” by Joseph Prestwich, 
M.A., F. R.S8.—Proc. Inst. C. E., vol. xl. 

These Papers, together with the discussions that followed them, 
furnish the student with the opinions of upwards of thirty men of 
science specially interested in the subject of wave action, either as — 
engineers, geologists, or physicists. 

More recently Mr. G. H. Kinahan has continued the discussion 
of the subject generally in the following Papers, viz. :— 

“Drifting Power of Tidal Currents versus that of Wind- 
waves.” —Proc. Roy. Irish Acad., s.s. vol. ii., Science, p. 443, 1875. 

*« Lagoons on the S.-H. Coast of Iveland.”—Proc. Inst. C.., 
vol. xliv. 

“On the Chesil Beach, &¢.”—Quarterly Journal Geological 
Society, 1877. 

*« The travelling of Sea Beaches.—’’ Proc. Inst. C.E., vol. lviii. 


1 The Papers marked thus [*] are referred to according to their pagination 
as reprints, the volumes of the Procceedings of the various Societies in which they 
are publihsed not being within my reach. 


SCIEN. PROC. R.D.S.— VOL, IV: PT. VI. 2A 


242 Scientific Proceedings, Royal Dublin Society. 


My object in the present Paper is twofold, being firstly, to set 
forward as plainly as possible the conflict of authority that exists 
on the action of sea waves, with a view to induce competent observ- 
ers to investigate a subject which is of such importance to both 
engineers and geologists; and, secondly, to attempt, by means of 
my own experiments and observations, to reconcile certain facts 
recorded by observers of unquestioned veracity, which facts seem 
at first sight to be quite irreconcileable, and have indeed been 
regarded as such. 

Nor can non-mathematical observers of wave-action place im- 
plicit reliance on the results obtained by those who have studied 
the subject from a theoretical point of view, as here also some of 
the authorities of greatest repute fail to agree. 

The Reports of Mr. Scott-Russell, published under the auspices 
of the British Association, and “ A Treatise on Tides and Waves,” 
by Sir George Airy, in the Hncyclopedia Metropolitana, are authori- 
ties much relied on at the present time. Referring to the former, 
Mr. Kinahan remarks :— 

“It might have been supposed that the exhaustive report on 
Waves by J. Scott-Russell, F. R.S., &c., should have decided the 
relative merits of the tidal currents and wind-waves in regard to 
their drifting powers” (Proc. R. I. Acad., s.s. vol. ii., p.448); whilst 
Lord Rayleigh has referred to the latter work as “ still probably 
the best authority on the subject” (“On Waves,” Phil. Mag., 
s. 5, vol. i., 1876, p. 262). 

Unfortunately the writers of these authoritative works were 
not agreed as to certain important points. Sir George Airy 
warned his readers against a too ready acceptance of Mr. Russell’s 
first Report on Waves, in the following terms :—“ We shall repeat 
our opinion of the great value of the experiments which we have 
abstracted, but we must warn the reader against attaching any 
importance to the theoretical expressions which are mingled with 
them in the original account” (‘Tides and Waves,” paragraph 
415). To this Mr. Russell subsequently replied :—“ .. . there is 
an irresistible body of evidence in favour of the conclusion that 
Mr. Airy’s formule do not present anything like even a plausible 
representation of the velocity of the wave of the first order, and 
that the formula I have adopted does as accurately represent them 
as the inevitable imperfections of all observations will admit. It 


‘Hunt—On' the Action of Waves on Sea-beaches, §c. 243 


is deeply to be deplored that the methods of investigation employed 
with so much knowledge, and applied with so much tact and dex- 
terity, should not have led him to a better result” (Trans. Brit. 
Assoc., 1844, p. 387). 

Thus, on the threshold of his inquiry into the action of waves 
on sea-beaches, the student is confronted with the fact that two 
authorities of great repute on the theory of waves are at variance 
as to the character of that particular form of wave, viz. the wave 
of the first order, to the exceptional powers of which the most 
striking wave phenomena of the coast are commonly attributed. 

The following extracts from the published opinions of authors 
of eminence in their respective branches of science will suffice 
to indicate the divergence of opinion that exists with regard to the 
following fundamental questions as to the action of waves on 
beaches, viz. :— 


The motion of shingle under water, and its cause, variously 
attributed to wind-waves, ground swells, tidal waves, tidal cur- 


rents, and other sub-marine currents ? 
The horizontal motion of shingle on beaches; whether the 


large material outstrip the small, or vice versa P 

The vertical motion of shingle on beaches; whether small or 
large attain the greatest altitude ? 

The degrading and accumulating action of waves; whether 
large waves or small exert the one action or the other ? 


As frequent reference will be made to the above-mentioned 
Papers of Messrs. Coode, Prestwich, and Redman, and to the dis- 
cussions that followed them, it will be convenient to quote them 
under the letters C., P., and R., respectively. 


[ Opinions, &e. 


2A 2 


244 


Scientific Proceedings, Royal Dublin Society. 


Oprntons AS TO THE MoTIonN oF SHINGLE UNDER WATER. 


Sir E. BeLcuer. 


«¢. . , the waves during heavy gales 
exercised power at very great depths; he 
had seen evidence of it in water fourteen 
fathoms deep. He thought the tide cur- 
rent did not affect depths of more than 
12 or 14 feet.”—R. 49. 


Professor AIRY. 


“ Although a swell might roll up the 
centre of the English Channel, yet there 
was a tendency in all such places for the 
direction of the waves to change gradu- 
ally, as towards the general line of shore, 
and to roll pebbles that way. He quite 
agreed in the opinion that very little was 
ascribable to the action of the tide.” — 
C. 38. 


Mr. Scorr RussEeLu. 


“Tt did not appear from the Admiralty 
charts, that near these shingle beaches 
there were any tidal currents of sufficient 
velocity to move stones of the bulk of 
those forming the banks; therefore he 
was warranted in attributing their for- 
mation, chiefly, if not entirely, to the 
action of wind-waves in conjunction with 
the local causes he had endeavoured to 
point out.”’—R. 63. 


Mr. R. A. C. AusTEN. 


“This process, by which masses of 
solid materials can be planed off parallel 
with the sea level, is due to the action of 
wind or surface-waves, inasmuch as in 
calm weather, when I have had opportu- 
nities of passimg over some of these plat- 
forms, I have felt convinced that the only 
other agent, namely the tidal streams, 


Mr. J. M. Renpet. 


‘c, . . his own opinion was, that shin- 
gle could scarcely be moved by the 
heaviest waves, at greater depths than 
three fathoms.’’—R. 64. 


Mr. Joseru GIBBs. 


“¢. , . the movement of the beach in 
question was not so much due to the 
ordinary flow, as to what might be termed 
submarine currents, which had the power 
of carrying pebbles along the shore at 
great depths until the waves cast them 
up as shingle.’’—C. 36. 


Mr. G. H. Kinawan. 


«. . . at Chesil the driftage is due to 
the flow-tide 
waves caused by the prevailing winds, 
while at Cahore the driftage is solely due 
to the flow-tide currents, its effect beimg 
modified by adverse wind-waves; . - - 
the sorting of the pebbles on Chesil 
beach is probably principally caused by 
the progressive increase in the velocity of 
the tidal current as it approaches the 
nodal or hinge-line of the tide in the 
English Channel.’’—Q.J.G.8., 1877, 
p. 41. 


current, augmented by 


Mr. J. Tuornui~tt HARRIson. 


‘¢ No wind-waves acting upon a beach 
would ever have excavated the bed of the 
bay to its present depth, and some other 
forces must therefore have been in opera- 
tion. Among those forces, he believed, 
were the tidal action, which was very 
considerable in the bay, and the ground- 
swells, which came into it with enormous 


Hunt—On the Action of Waves on Sea-beaches, &c. 


had not sufficient velocity to exercise any 
mechanical power whatever.’’—Q.J.G.S. 
vol. vi. p. 73. 


“The two actions, first, that of wind- 
wayes when they break in shallow water ; 
and secondly, that of the tidal stream, 
are alone engaged in fashioning and ar- 
ranging the materials of the sea-bed... . 
Ineyery sea the power of abrasion is con- 
fined to a marginal zone, and that of dis- 
persion, though with a wider range, 
extends only to the minuter particles of 
matter.’”’—Idid. p. 75. 


Mr. Joun Murray. 


“On the east coast, the shipping 
which frequented the coal ports, cast out 
at sea, particularly in fine weather, great 
quantities of ballast in water 10 to 
20 fathoms deep. The greater part of 
this ballast was composed of sand and 
pebbles dredged from the Thames, with 
chalk and other matter foreign to the Hast 
Coast. After storms, the shore between 
the Tyne and Hartlepool was strewed 
with these pebbles, which could only 
have been brought there by the action 
of the waves at the depths stated.’’— 
C. 34. 


Mr. Josuua WItson. 


«c. . waves possessed sufficient power 
to move shingle at considerable depths: 
inasmuch as though, at Sunderland, no 
vessels were permitted to throw ballast 
overboard at a less depth than 5 
fathoms, yet great quantities of flint 
pebbles were found on the beach, which 
could only have been derived from that 
source, as they were not met with ‘in 
situ’ in any cliffs within the range 
of the seas bearing on Sunderland.’’— 
R. 55. 


245 


violence . .. The Astronomer Royal’s! 
view, that the materials which formed 
the bank were piled up by the sea, after 
haying been torn up by the violence of 
the surf from the bottom, coincided very 
nearly with his own.’’—P. 36 and 38. 


Mr. J. N. Dovewass. 


“¢. , . the travel of the shingle was, 
he thought, chiefly due to the effects of 
the ocean-wave or ground-swell.... He 
quite agreed with the opinion expressed 
by Mr. J. T. Harrison, that the beach 
(Chesil) had been largely supplied with 
material from the bottom of the bay ; 
indeed, he considered it quite possible 
that a portion of the supply had been 
transported from positions westward of 
the Start.—P. 45 and 46. 


Professor PRestwicH 


thought that the shingle was driven on 
to the Chesil Bank “‘by the storms to 
which this coast is exposed acting proba- 
bly conjointly with the great tidal wave. 
This wave, passing from the ocean into 
the shallower waters of the channel, be- 
comes a wave of translation, which under 
certain conditions, such as a rapid de- 
crease of depth, or the narrowing of its 
channel, possesses a greater or less propel- 
ling and eroding power.’’—P. 18. 


Mr. Kinanan. 


“Lyme Bay ... is open, and the 
Chesil Beach is exposed to the full force, 
not only of the tidal current, but also of 
the most prevailing and effective winds. 
The current also is progressively increas- 
ing in velocity as it goes eastward, and 
therefore carries large fragments with it 
to be driven on shore... .”’—Q.J.G.S., 
1877, p. 40. 


1 Sir G. Airy. 


246 


Scientific Proceedings, Royal Dublin Society. 


OPINIONS AS TO THE RELATIVE Morton oF LARGE AND SMALL SHINGLE 
ALONG SHORE. 


Professor (now Sir Gzrorce) Airy. 


‘¢, , . the progression in smallness of 
the pebbles pointed to the direction from 
which the current or fluctuation must 
have transported them . . .; they must 
have been transported from the end of 
the bank, where they were large, towards 
the end where they were small.””—P. 32. 


Admiral Spratt. 


«|. . On one occasion, on the coast 
of Egypt, he put overboard five bags of 
clinkers, weighing from 3 lbs., 4 lbs., and 
5 lbs., to a few ounces; and on visiting 
the spot a fortnight afterwards to 
examine the effect of wave-action, he 
found at 450 yards to leeward the largest 
pieces of clinker nearest the point of start- 
ing, one weighing 34 lbs. and the other 
2 Ibs.; at 700 yards and 800 yards they 
weighed less than 1 lb., and at 1500 
or 1600 yards, from 4 to } oz. only. 
Thus the heaviest and largest pieces did 
not travel the farthest, but the contrary. 
—P. 31. 


Mr. A. GEIKIE. 


‘A prevalent wind, by creating a cur- 
rent in a given direction, or a strong 
tidal current setting along a coast-line, 
will cause the shingle to travel coastwise, 
the stones getting more and more rounded 
and reduced in size as they recede from 
their sources. The Chesil Bank, which 
runs as a natural breakwater 16 miles 
long connecting the Isle of Portland 
with the mainland of Dorsetshire, con- 
sists of rounded shingle which is con- 
stantly being driven westwards.’’—Teat- 
Book of Geology, p. 435. 


Mr. (now Sir Joun) Coopz. 


«¢_. . the cause of the large shingle 
being found, at what is called ‘to leeward’ 
upon any beach, is due to the fact of the 
large pebbles moving more readily than 
the small, . . .”’—C. 25. 


Mr. Repman. 


‘Undoubtedly the largest shingle tra- 
velled to leeward, ... ”—P. 44. 


Mr. T. Metiarp Reape. 


“It was not, as Sir John Coode sup- 
posed, that the large stones were the more 
easily moved, for the reverse could be 
readily proved, .. . the large stones, in 
fact, travelled up a lesser gradient, and 
consequently to a greater distance.’’— 
P. 24. 


Sir Coarztes Lyeui 


“. . . admitted the apparent paradox of 
the largest pebbles at the Chesil Bank 
being found to leeward; or farthest from 
the source whence they were derived; as 
he took it for granted that they did come 
from the westward. . . .’’—R. 47. 


“¢. . . throughout the Chesil Bank the 
pebbles increase gradually in size as we 
proceed south-eastward, or as we go far- 
ther from the quarter which supplied 
them.”—Lyell’s Principles Geol. vol. i. 
p- 589, 11th ed. 


Mr. R. A. C. Austen. 


‘¢ Along our own southern coasts the 
movement of shingle is from west to 
east, and on the opposite coast of France 
itis the same. . . . On the Chesil beach 
may be collected pebbles of limestone, 
greenstone, trap, and old red sandstone, 
derived from the older rocks of South 
Deyon,”’—Q.J.G.S, vol. vi. pp. 72, 73. 


Hunt—On the Action of Waves on Sea-beaches, &c. 


247 


OPINIONS AS TO THE ACCUMULATIVE AND Destructive AcTION oF WAVES 
on BEACH-SHINGLE. 


Mr. Cooper. 


“Tt is known that shingle accumulates 
upon any beach with off-shore winds, 
whilst it is carried off, or scoured away, 
during on-shore winds, and more espe- 
cially by the ground-swell which folloys.”’ 
—C. 23. 


Mr. Parmer. 


“IT watched for an opportunity of 
witnessing that rate of succession which 
exhibited the destructive and accumula- 
tive actions in their smallest degrees; 
and I observed that when ten breakers 
arrived in one minute, the destructive 
action was but just evinced; and that 
when only eight breakers arrived in the 
same period, the pebbles began to accu- 
mulate ; which facts harmonized with my 
observations made at Sandgate and Folke- 
stone, viz. that the difference between 
the two actions was determined by the 
rapidity in succession of the waves upon 
the shore.””—Tvans. R. S., 1834, p. 571. 


Mr. Kinanan. 


‘‘The ordinary wind-waves assist the 
flow-tide currents when they are going 
in the same, or nearly the same, direction 
with those currents. If they strike the 
beach at a right angle, or nearly so, they 
pile it up, forming ‘fulls’ and ‘storm- 
beaches’ -’’ —Travelling of Sea 
Beaches (loc. cit.), p. 3. 


Mr. Kinahan, writing of the east coast 
of Ireland between Carnsore and Dalkey, 
says :— 

“W. and §.-W. winds generate 
ground-swells, which usually cut out 
the beaches.’’—Jbid. (loc. cit.), p. 4. 


(These winds are off-shore.) 


“Ground swells with E. winds some- 
times seem to assist in filling in the 
beaches, but with N.-E.. winds they 
cut out.”’—Jbid. (loc. cit.), p. 5. 


(These winds are on-shore.) 


Mr. Coopr. 


‘‘The views here expressed’? (Mr. 
Palmer’s) ‘‘are opposed to the con- 
clusions arrived at from the Author’s 
observations on the Chesil Bank and else- 
where. The rule, as far as one can be 
formed from the number of waves in a 
given time, appears to be, that seven, or 
any less number of wayes per minute, 
indicate the destructive action, and nine, 
or any greater number, the accumuiative 
action; but no very precise rule can be 
formed upon this basis.”’—C. 23, 


248 Scientific Proceedings, Royal Dublin Society. 


Although no one would venture to question the bona fides of 
an observation recorded by Mr. Palmer, Sir John Coode, or 
Mr. Kinahan, yet, in the above extracts. on the subject of accu- 
mulation and removal of beach material, we find the followimg 
facts vouched for, viz. :— 


(1). “Shingle accumulates with off-shore winds.” 


(2). “ W. and S.-W. winds” (between Carnsore and Dalkey 
where they are off-shore) “ generate ground-swells, which usually 
cut out the beaches.” 


(3). “Shingle is carried off . . . more especially by the 
ground-swell which follows” (on-shore winds). 

(4). “ Ground-swells with E. winds” (these being on-shore 
at the locality referred to) “‘ sometimes seem to assist in filling in 
the beaches.” 


(5). “ When ten breakers arrived in one minute, the destruc- 
tive action was but just evinced; when only eight breakers arrived 
in the same period, the pebbles began to accumulate.” 


(6). “. . . Seven, or any less number of waves per minute 
indicate the destructive action, and nine, or any greater number, 
the accumulative action.” 


In the presence of statements so contradictory as the above to 
all appearances are, there is some risk of an observer relying on 
his own observations to the exclusion of those previously recorded. 
The conflict of observation between Mr. Palmer and Sir John 
Coode (quoted above) seems a case in point. Sir John Coode, 
finding his own observations apparently irreconcileable with those 
of Mr. Palmer, seems driven to the expedient of relegating 
Mr. Palmer’s observations to the rank of “ views,” as opposed to 
the “conclusions” arrived at from his own. Taking into con- 
sideration the eminence of the two observers, I cannot but think 
that no such mode of explanation is admissible. In both cases we 
have to deal, not with “ views,”’ but with well-attested facts. 


The following observations and experiment, made in the autumn 
of 1882, with the object of solving, if possible, some of the problems 
suggested by the above extracts, may be worth recording, if only 


Hunt—On the Action of Waves on Sea-beaches, &c. 249 


to show how easily students of wave-action may be misled by a 
misinterpretation of isolated observations :— 


(1). Sept. 3, 1883.—Cove under St. Lawrence, Isle of Wight. 
Heavy sea. Waves, six per minute. Strand, small flint shingle, 
or coarse sand. ‘Tide rising. The waves carried off every stone I 
placed on the beach, about mean water level, without apparently 
disturbing the coarse sand. One of the stones was nearly spherical, 
and some ten inches in diameter. 


(2). Sept. 27, 1882.—Sands under Torbay Hotel, Torquay. 
Wind N.W., along shore. Small waves breaking on the sands 
from 8.W. Low water. Whilst wading, observed the motions of 
light objects on the bottom. . Could not see that they were driven 
forwards by the waves, but observed that they were driven to lee- 
ward by the wind, which seemed to drive the water before it, and 
to cause a current. When the tide was flowing quickly, light ob- 
jects (e.g. an empty echinus shell) were driven before it shore- 
wards, rather fast; but here it was clearly the tidal current that 
was the motive power. Where the surf was breaking I could not 
see the bottom, though only a few inches below the surface. I 
came to the conclusion that the sand was stirred up by the plung- 
ing waves, and that what became of it then must depend upon 
currents. . 


(3). Sept. 28, 1882.—Sands (flat) at Livermead. Tide flowing. 
Determined to ascertain whether the little “ translation’ waves 
running along the shallow water, with their forward slopes 
apparently high above the level of the water in front, had any 
power to drive objects before them. A piece of large leathery sea- 
weed (/aminaria) showed a decided tendency to go shorewards; but. 
this arose from the fact that it was carried along bodily by the 
shoreward current, to whose impulse it yielded at once; whereas, 
having anchored itself when the current slackened, it did not start 
seawards till the gradually increasing outward current had attained 
considerable velocity, and spent much of its power. A piece of 
heavy water-soaked stick was carried away seawards much faster 
than the piece of /aminaria was carried shorewards. The stick 
was too heavy for the incoming waves to lift, and had to be rolled 


200 Scientific Proceedings, Royal Dublin Society. . 


both ways; whereas the piece of Jaminaria, though rolled back- 
wards, was light enough to be lifted forwards. 


(4). The foregoing observations having been made, the tide, 
having in the meantime covered the flat sands, had reached a slop- 
ing beach. Thrusting a razor shell (so/en) into the sand of this 
beach for a mark, I watched the action of the waves on a stone | 
lying on the slope. It gradually worked its way up the rather 
steep incline, notwithstanding the fact already referred to, that the 
water-soaked stick had travelled seawards down one whose gradient 
was much less. 


ExrrerimEent.—Sept. 30, 1882.—In front of a small sloping 
sand-beach, in my experimental tank, I placed a large slate, care- 
fully levelled with a spirit-level. ‘The slate was then covered’ with 
water to the depth of about one inch, so that the waves produced 
by my wave-generator might break heavily on it. I found that 
marbles placed on the slate evinced a decided tendency to travel 
outwards against the waves, but that fragments of crushed granite 
were washed shorewards. Once only wasa piece of granite washed 
off the slate. 


(5). Oct. 3, 1882.—Walked from south end of Goodrington 
sands (Torbay) to north-east end, of Holloweombe sands. Tide 
ebbing. Came to the conclusion that when the waves do not break, 
the combined action of the inward and outward currents washed 
objects on the bottom outwards, but that breakers carried forwards 
whatever they could lift. 


(6). Oct. 4, 1882.—Beach east of raised beach at Hope’s Nose. 
Tide (neaps) ebbing. Waves inclined to roll stones up the sand- 
slope. Sand softish and coarse; seemed to offer much resistance 
to descent of the stones. One rounded flint, the size of an egg, 
was driven up several times. 


The breakers were most decided in their upward action; but 
even the wash backwards and forwards showed no tendency towards 
downward propulsion. (N.B.—This conflicts with Observation (6) ). 


Hunt—On the Action of Waves on Sea-beaches, §c. 251 


The above six observations way be tabulated as follow :— 


Number of State of Tide. Motion of beach-stones, or other 
Observation. movable objects. 


1 Flowing . .| Seaward. 
2 Low Water .| Neutral. 
: Piece of daminaria—shoreward. 
Se Flowing . . { Water-soaked stick—seaward. 
4 Flowing . .| Shoreward. 
: Breakers—shoreward. 
5 Ebbing. . - { Wash—seaward. 


; Breakers—shoreward. 
6 Ebbing. . - ne oe 


Hitherto I had failed in my attempt to reconcile the conflicting 
observations of the authorities referred to in the preceding pages, 
My own observations had been as contradictory, and seemingly as 
irreconcileable, as theirs. The only fact clearly made out seemed to 
be, that the forces acting on marine shingle, or on other objects 
under water, were very evenly balanced, and that a slight change 
either in their mode of application or in the character of the shingle 
or other objects on which they acted might, in any particular case, 
completely reverse the effect of their action. 

Having in the preceding pages shown the uncertainty which 
prevails at present as to the action of waves on sea-beaches, I will 
now proceed with my attempt to reconcile some of the observations 
recorded above, my own included, which observations often seem as 
inconsistent and contradictory as they are well attested. 

The first step towards this result will be an endeavour to dis- 
prove the assumption: that is commonly made, that under certain 
circumstances an ordinary oscillating marine wave can convert 
itself into a wave of translation ; or, as Mr. Russell puts it, that 
“‘the wave of the second order may disappear, and a wave of the 
first order take its place.” (Zrans. Brit. Assoc. 1844, p. 872.) 
Mr. Russell defines the two orders of waves as follows :—‘“ The 
wave of translation is the wave of the FIRST ORDER, and consists in a 
motion of translation of the whole mass of fluid from one place to 
another, in which it finally reposes.... . ” (Ibid. p. 317.) “This 


202 Scientific Proceedings, Royal Dublin Society. 


wave-form has its surface wholly raised above the level of repose of 
the fluid. This is what I mean to express by calling this wave 
wholly positive. . . . The wave-proper of the first order is wholly 
positive.” (Ibid. 340.) 

‘¢The wave of the sECOND ORDER is partly positive and partly 
negative, each height having a companion hollow, and this is the com- 
monest order of visible water-wave, being similar to the usual wind- 
waves, in which the surface of the water visibly oscillates above and 
below the level of repose... . . ” (Ibid. 317.) 

Mr. Russell distinctly asserts that ordinary sea-waves of the 
second order become, on certain occasions, entirely transformed into 
waves of his first order. He writes:—“ After a wave has first 
been made to break on the shore, it does not cease to travel, but 
if the slope be gentle, the beach shallow and very extended (as it 
sometimes is for a mile inwards from the breaking point, if the 
waves be large), the whole inner portion of the beach is covered 
with positive waves of the first order, from among which all waves 
of the second order have disappeared. This accounts for the 
phcenomenon of breakers transporting shingle and wreck and other 
substances shorewards after a certain point; at a great distance 
from shore, or where the shores are deep and abrupt, the wave is 
of the second order, and a body floating near the surface is alter- 
nately carried forward and backward by the waves, neither is the 
water affected to a great depth ; whereas nearer the shore, the whole 
action of the wave is inwards,! and the force extends to the bottom 
of the water, and stirs the shingle shorewards; hence the abrupt- 
ness also of the shingle and sand near the margin of the shore where 
the breakers generally run.” (Jdid. p. 373.) 

The results arrived at by Mr. Russell as to the nature of his 
wave of the first order were obtained by means of a series of 
elaborate experiments; but the above conclusions as to the con- 
‘version of waves of the second order into those of the first order 
seem to have been based on an insuflicient number of general obser- 
vations that were not brought to the test of experiment. 


! According to Mr. Russell the wave may assume this character before it breaks :— 
“He must undoubtedly attribute the greatest moving power to the greatest depth of 
water, because the largest and most powerful wave would thus be created, and before 
they broke they would exercise the greatest amount of mechanical power to lift and 
convey the shingle.”’ (R. 53.) 


Hunt—On the Action of Waves on Sea-beaches, &c. 203 


The assertion that is made is sufficiently startling, as it is in 
effect that a wave of oscillation that propagates itself by means of 
a pendulum-like vibration about the level of repose of the water 
can be raised entirely above that level, and there sustained, without 
the intervention of any force outside itself. 

Mr Russell, in his first report to the British Association, describes 
an experiment made with marine waves, in the following passage :— 
“The phenomena of waves breaking on the shore were observed 
principally on a very fine smooth beach of sand, having a slope 
towards the sea of 1: in 50°; so perfectly plane and level was it at 
the time when the observations were made, that a single wave a 
mile in breadth might be observed advancing to the shore, so per- 
fectly parallel to the edge of the water that the whole wave rose, 
became cusped, and broke at the same instant; a line of graduated 
rods was fixed in the water at different depths from 6 inches to 
6 feet in length, and it was observed that every wave broke exactly 
when its height above the antecedent hollow was equal to the depth 
of the water.”—(TZrans. Brit. Assoc., 1837, p. 450.) ‘The words I 
have italicised, if taken in their literal sense, would be sufficient to 
settle the question at issue, for waves with antecedent hollows, by 
Mr. Russell’s own definition, are not waves of the first order, as the 
latter have their surfaces ‘‘ wholly raised above the level of repose of 
the fluid.” Sir George Airy, commenting on this passage (Tides and 
Waves, 403), remarks that Mr. Russell does not state ‘“‘ whether this 
depth was measured from the mean level of the surface, or from the 
bottom of the hollow,’* and thus clearly assumes that the ‘“ bottom 
of the hollow” and Mr. Russell’s “antecedent hollow” are not 
equivalent to the level of repose. Mr. Russell’s meaning is, how- 
ever, open to some doubt, as on a subsequent occasion he defined 
“the limit of height of a wave of the first order” as “a height 
above the bottom of the channel equal to double the depth of the 
water in repose.” —(TZrans. Brit. Assoc., 1844, p. 352.) 

There can, however, be little doubt that waves derived from 
waves of oscillation under the circumstances described by Mr. 


1 The question is whether, in the passage referred to, Mr. Russell uses the words 
“antecedent hollow” in their ordinary sense as descriptive of a depression extending 
below the level of repose of the water, or as descriptive of the depression between two 
waves of his first order, which depression, according to his own definition, must not (as 
part of a wave of the first order) extend below the said level of repose. 


204 Scientific Proceedings, Royal Dublin Society. 


Russell are accompanied by antecedent hollows, though the depres- 
sion may be small, and very extended, in proportion to the height 
of the wave. ‘The fact can be easily proved in the case of artificial 
oscillating waves made to roll over water of gradually diminishing 
depth. If under these circumstances a wire be stretched across: the 
water at the level of repose, it will be found that on the approach of 
a wave the water will sink away, and leave the wire suspended in 
mid-air, thus showing that each wave is preceded by a depression. 

If oscillating waves, on approaching the shore, were transformed 
into waves of translation, raised entirely above the level of repose 
of the water, it would naturally follow that such waves would 
plunge on the shore landwards of the margin of repose for the time 
being. 

This point, as affecting the erosion of the land by sea-waves, is 
of some importance to geologists. Professor J. D. Dana seems to 
refer to it in the following passage: ‘Since a wave is a body of 
water rising above the general surface, and when thus elevated 
makes its plunge on the shore, it follows that the upper line of 
wearing action may be considerably above high-tide level. Again, 
the lower limit of erosion is above Jow-tide level; . . . . there is there- 
fore, a level of greatest wear, ... . and another of no wear, which is 
just above low tide.””—(IMan. of Geol., 3rd ed., p. 676.) 

Now, this statement, though strictly in accordance with Mr. 
Russell’s theory, has, so far as I can ascertain, no foundation in fact. 
An attentive study of heavy waves breaking on a beach will satisfy 
the observer that all waves derived from oscillating waves break 
far below, or seawards of, the margin of repose of the water. As 
it is sometimes difficult on the sea-shore to detect the line of mean 
level for the time being, it will, perhaps, be better in the present 
inquiry to let observation be preceded by experiment. 

On the 5th October, 1882, I banked up the sand at one end of 
my experimental tank, and caused waves to attack this artifical cliff 
for about three quarter of an hour. My object was to ascertain the 
general action of waves in tearing down and distributing beach 
material, and I find no special entry in my note-book as to the re- 
lation of the line of plunging with the water margin ; but a series 
of careful measurements recorded at the time supplies the informa- 


tion required. 
At the close of the experiment, the breadth of the strand from 


Hunt—On the Action of Waves on Sea-beaches, &c. 255 


cliff to water margin, and the distance from water margin to the 
plunging line, were measured at five equi-distant points, viz. at the 
two sides of the tank, at the centre, and at the two intermediate 
points, with the following result, viz. :— 


came | Inches. 


| verage 


SL BP eer ae 


Breadth of strand from cliff to ) 
margin of water . : : f . 


Margin of water to plunging 


line of waves 


In this experiment the waves were furnished with a cliff of soft 
sand to work on, and formed their own beach and along-shore bot- 
tom, which, asin nature, was a comparatively flat one. 

Subsequently I made some special experiments, to ascertain the 
point of plunging relative to the point of furthest reach of waves 
breaking on a beach. A large roofing slate, with parallel lines 
ruled across it one inch apart, was employed. 

This slate being laid on the artificial beach, with one of the cross 
lines coincident with the margin of the water, enabled the ob- 
server to see at a glance how many inches “ seaward”’ of the margin 
of repose the waves plunged, and how many inches shoreward of 
the same margin they reached. One particular line was always used 
for marking the water-level, and was distinguished by the letters 
W.L. From this line the remainder were numbered 1, 2,3.... 
in each direction. In an experiment made in February, 1883, the 
highest reach of the waves, as defined by a row of light chips 
washed on to the slate, was just under three inches above the water- 
line, whilst the line of plunging (rapidly scratched on the slate 
during the progress of the experiment) was over eight inches below 
the water line. The slope of the slate was not measured. 

On a subsequent occasion the experiment was repeated, with the 
slate inclined at an angle of 6 degrees, and with waves at the rate 
of 98 per minute. In this case the waves plunged about eight 
inches short of the margin of repose, whilst their furthest reach was 
about five inches beyond it. In both these experiments the line of 


206 Scientific Proceedings, Royal Dublin Society. 


plunge of the waves was more remote from the water margin on 
the one side than the line of furthest reach was on the other. 

With the eye trained by observing the plunge of waves, where 
the margin of repose is known, it is not difficult to make a fair esti- 
mate of that margin when heavy waves are rolling on to a sea- 
beach, and to assure oneself that in no case do heavy waves plunge 
anywhere near the margin of repose of the water for the time being 
—I say advisedly, heavy waves, for the action of short wind-waves 
is at times completely masked and rendered unintelligible by the 
presence of long, low swells, whose concurrent action may occa- 
sionally pass unobserved. 

In investigating the action of an oscillating wave approaching — 
the shore it will be well to select an ordinary swell as being no 
longer under the influence of the wind or other force that may 
have brought it into existence. — 

In the case of such a wave, authorities seem agreed that the 
motion is one of oscillation solely, and that there is no translation 
of the water in the direction of propagation of the wave. Ina 
passage already quoted, Mr. Russell, referring to a wave of this 
kind, says that “‘a body floating near the surface is alternately 
carried forward and backward by the waves... . . ” Lord Rayleigh, 
describing “ periodic waves in deep water,” says that “the motion of 
each particle of the fluid is in a circle, which is described with uni- 
form velocity.” (Phil. Mag., 8.5, vol.i., 1876, p. 267.) The direction 
of this motion we may learn from Sir George Airy :—“ The 
particle revolves uniformly in the circle of which we have spoken ; 
moving forwards when at the highest part of the circle, and back- 
wards when at the lowest part.” (Tides and Waves, 182.) 

From the above descriptions of the motion of water under the 
influence of an oscillating wave it will be seen that the motion im- 
parted to a floating body by such a wave will be more accurately 
described as backward and forward than as ‘“ forward and back- 
ward.” It is important to bear in mind that the primary motion 
of a floating object is towards the advancing wave, and therefore 
backwards as referred to the direction of advance of the wave; and 
that the wave draws its supplies entirely from the front, and not 
from the rear. The truth of this can be shown from the facts that 
the ridge of an oscillating wave is preceded by a depression, and 
that the motion of the wave is much more rapid than the motion of 


Hunt—On the Action of Waves on Sea-beaches, &c. 257 


_ the water composing it, even when the water at the highest part 
of the wave is travelling with its greatest velocity in the same 
direction as the wave. 

Dr. Scoresby observed storm-waves in the Atlantic having a 
period of 16 seconds, and a speed of 324 miles per hour. For con- 
venience sake we may consider the hypothetical case of a swell with 
a period of 15 seconds, a speed of 80 miles, and a height, from 
trough to crest, of 5 feet. In such a swell the circle described by 
a surface particle would have, in round numbers, a circumference of 
15 feet, and the time taken in describing it would be 15 seconds. 
Thus the speed of the particle in a forward direction on the crest of 
the wave would be one foot per second, or 3600 feet per hour. But 
the speed of the wave itself is 30 miles, or 158,400 feet per hour ; 
from which it follows that the speed of the wave is 44 times the 
speed of the water composing it, even when the latter, on the crest 
of the wave, is moving at its greatest velocity in the direction of the 
wave. Under these circumstances it is clearly impossible for such 
a wave to draw any of its supplies from the rear. The advancing 
wave depends entirely for its continued existence on the water in 
front of it, and on that only. 

From the fact that a particle on the surface of the water moves 
“in a circle which is described with uniform velocity,” it follows 
that each wave gives rise to two currents that are equal and 
opposite, the first flowing in a direction contrary to that of the 
advancing wave, the second flowing in the same direction as the 
wave. It will be convenient to refer to these currents as the 
primary and the secondary—terms descriptive of their order of 
sequence in point of time. 

When a swell such as I have described reaches water sufficiently 
shallow for it (to use Mr. Russell’s expression) “to feel the bottom,’ 
the primary current, extending as it then does, though with varying 
intensity, throughout the whole mass of the water from surface to 
bottom, flows over and in contact with the said bottom, in its pas- 
sage to meet the advancing crest. The secondary current returning: 
with, and following the crest, affects the bottom in a similar manner, 
though in an opposite direction. ‘Thus the circular motion of a 
surface particle in deep water is resolved, so far as the bottom is 
concerned, into two equal and opposite horizontal currents. ‘The 


action of these currents on a movable object on the bottom is, in 
SCIEN. PROC, R.D.S.—YOL. IV. PT. VI. eB 


258 Scientific Proceedings, Royal Dublin Society. 


the first place, a motion of translation towards the advancing wave- 
crest, and in the second, a motion of translation in the same direc- 
tion as that crest, the said object, if the bottom be level, being 
ultimately deposited at or about the same spot whence it set out. 
As the water shoals, and the depth in proportion to the size of the 
wave diminishes, the currents increase in amplitude and intensity ; 
but, so far as I can ascertain, remain equal and opposite, so long as 
the wave does not plunge. The action of these currents can be ob- 
served either from a boat at sea, when the water is clear and the 
waves of convenient dimensions ; or, in the case of artificial waves, 
in a suitable tank. 

When a wave of oscillation is passing over and through a prac- 
tically frictionless fluid, such as water, it may travel for hundreds of 
miles from its point of origin, drawing its supplies in advance, with- 
out encountering appreciable resistance; but the moment such a 
wave begins to feel the bottom, the two currents to which it gives 
rise encounter resistance ; the wave has begun to expend itself in 
doing appreciable work, which work, if continued, must sooner or 
later reduce its motion to nothing. The action of the bottom on a 
wave may be compared to that of a friction-brake on a machine: if 
applied gradually it will by insensible degrees bring the machine to 
a standstill; if applied too suddenly it may produce the same result 
by a disruption of the machine itself. When, in the case of a wave, 
the break is suddenly applied in the form of a steep beach, the wave 
plunges, and is destroyed almost instantaneously. When the brake 
is applied very gradually, by the bottom shoaling slowly, the wave 
may be reduced to very small dimensions without breaking at all. 

The dissipation of waves without breaking may be occasionally 
witnessed in the shallow water over mud-banks in estuaries, where 
the distance the wave has to travel in shallow water is great in pro- 
portion to the length of the wave. On the sea-shore, the distance 
a wave has to travel after feeling the bottom is commonly so short 
compared with the size of the wave, that the reduction of the wave 
by the friction of the bottom cannot keep pace with the rate of 
shoaling of the water. 

If the wave survive to reach the shore, as is usually the case, 
the primary and secondary currents will be found in their relative 
sequence, the water being drawn off from the shore as the wave-crest 
approaches, 


Hunt—On the Action of Waves on Sea-beaches, &c. 209 


Having endeavoured to show that there is no evidence that a 
wave of oscillation is transformed into a wave of translation on near- 
ing the shore (although it gives rise to two distinct currents of trans- 
lation in opposite directions), I will proceed to discuss the action of 
these currents: firstly, on objects floating on the surface ; secondly, 
on movable objects resting on the bottom. It seems clear that, if 
these currents are equal and opposite, an object under their influ- 
ence will travel with the one that is applied to the best advantage. 

In the case of floating objects, the application of the two wave- 
currents is influenced by the form that the wave assumes on entering 
shallow water. The steep anterior wave-slope acts diversely on 
different objects according to their form and weight. 

This fact was brought to my notice by accident. Whilst 
watching some waves running over a shelving bottom in my tank 
I observed that a chip of wood dropped into the water at a certain 
point would recede from the shore, that the cork of a phial dropped 
in in the same place would go towards the shore, but that a small 
piece of water-soaked wood would go from the shore with the chip. 
On this occasion there was a slight surface current from the shore 
outward, which explained the motion of the light chip; but this 
current did not account for the cork going one way, and the water- 
soaked wood the other. The explanation is as follows :—The out- 
ward current, which carried the light chip over the steep slopes of 
the advancing waves, was unequal to the task of carrying the cork 
outwards so fast as the latter slid down the wave-slopes shorewards. 
The cork, by hanging on the anterior wave-slopes, was under the 
influence of the forward wave-current in each wave longer than 
under that of the backward, and thus by the mere accident of weight 
travelled in a contrary direction to that of the chip. The water- 
soaked piece of wood, though heavier than either chip or cork, did 
not attempt to surmount the waves. Its specific gravity approxi- 
mating to that of water, it had little buoyancy, and the waves ac- 
cordingly broke over it. Thus, whilst exposed to the full force of 
the backward wave-currents, it partially evaded the forward currents, 
and in consequence travelled away from the shore, under the 
influence of the said backward currents. On another occasion I 
found that when the waves acted on a deep narrow toy-boat sunk 
to the water’s edge, end on, the boat travelled with them ; but that 

. . 2B2 


260 Scientific Proceedings, Royal Dublin Society. 


when the boat was placed broadside on to the waves, she travelled 
against them. 

This result was obtained by wave-action alone, there being no 
perceptible current. ‘The explanation is the same as in the case of 
the water-soaked wood. When the boat met the waves broadside 
on, their crests broke clean over and beyond her decks, and she thus 
evaded a portion of the forward, or secondary wave-current, whilst 
encountering the full force of the primary; but when placed end 
on, she received the full force of the secondary, or forward current, 
as the portion that broke over her stern now fell upon her deck, in- 
stead of passing over it. These experiments seem to show that a 
floating object, if under the influence of wave-currents alone, will | 
travel in the direction of that current whose force is applied to the 
best advantage, either on account of its action (in the case of any 
particular object) being of longer continuance, or of greater intensity, 
than that of the opposite current. 

It has been stated that in the event of two ships rolling about in 
a calm at sea being in dangerous proximity, if they be headed away 
from each other, each vessel will slowly forge ahead, and draw away 
from its neighbour. In the case of a vessel having fore and aft 
sails this result might be obtained by the action of the sails flapping 
backwards and forwards ; but it seems more probable that the slow 
propulsion of the vessel is caused by the stern, with the swinging 
rudder, offering a greater resistance to the wave-current impinging 
upon it than the bow offers to the opposite current. It may be ob- 
served that before the days of steam and clipper ships the difference 
in form between bow and stern was much greater than at the 
present day. 

Perhaps no better proof can be advanced of the truth of my 
proposition, that a floating object will travel in the direction of the 
wayve-current that is applied to the best advantage, than the 
example orded by the natives of Hawaii in their sport of surf- 
riding. Harper's Weekly, of March 17th, 1883, gives the following 
account of it :—“ The surf-riders, .... plunging beneath the first 
wave .... rise beyond it, and swim out to sea till they meet 
another, and then another, in each case diving just at the right 
~ moment to allow the billow to pass overthem. If they miscalculate 
by one second, the surf catches them, and dashes them shorewards, 


Hunt—On the Action of Waves on Sea-beaches, &c. 261 


when they need to be good swimmers to escape being battered on 
the rocks.” 

On the return journey the aim of the surf-riders is to “ mount 
the biggest billow, which carries them shorewards at lightning 
Speed..... Should the rider fail to keep his plank at exactly the 
right angle on the crest of the green billow he will be overtaken by 
the breaking surf of the wave which follows, and to avoid this must 
again dive beneath it, and swim out to sea to make a fresh start.” 
From the above description it would appear that so long as he can 
avoid the breaking crest the Hawaian “ surf-rider”’ can swim out 
to sea encumbered with his surf-board in the face of “ great green 
billows” (that) “come rushing in with overwhelming force,” and 
that by skilfully taking advantage of the steep slopes at or near 
their crests he can return to the shore with the speed of the waves 
themselves. 

In the preceding pages I have endeavoured to show that there 
is no evidence that a wave of oscillation is transformed into a wave 
of translation on passing into shallow water, and that the observed 
motions of floating objects can be explained without assuming the 
existence of such waves of translation. My next step will be toin- 
vestigate the actions of waves on objects lying within their reach 
on the sea-bottom, with a view to ascertain whether the wave 
of translation can be equally well dispensed with in their case. 
This part of my subject may be considered under two heads, viz.: 
(1) the action of waves before plunging, and (2) their action after 
plunging. 

The first of these sections has been dealt with incidentally in my 
Paper on “ Ripple-mark,”’ from which the following passage may be 
quoted, as recording an observation in point :— 

“One fine and almost calm day in the summer of 1881, being 
at Broadsands, in Torbay, and seeing that the strand was covered 
with ripple-marks, I proceeded to watch carefully the action of the 
water, with the view of ascertaining, if possible, the process of their 
formation. Floating in my boat a few yards from the shore, in 
about eighteen inches of water, I narrowly scanned the effect of the 
very gentle swell that was breaking on the beach. I observed that 
a small shell lying in one of the furrows, instead of being steadily 
washed shorewards by the incoming waves, was washed backwards 


262 Scientific Proceedings, Royal Dublin Society. 


and forwards from one furrow to another; sometimes it would 
stop on the intervening ridge, and so for the moment help to build 
it up; at others it would fall over into the furrow towards which, 
for the moment, it was being propelled; but in no case did 
it show any tendency to travel continuously in any particular 
direction along the bottom.”—(Proc. Royal Soc., vol. xxxiv. 
p- 3.) It will be observed that in this instance the observation was 
made in very shallow water, at a poit close behind the plunging 
line of the wave, and that even here the primary and secondary 
wave-currents were so evenly balanced, that though in the case of 
light objects there was abundant horizontal alternating motion 
on the bottom, I was unable to detect any sign of one wave-current 
being more powerful than the other, still less that the incoming 
swells were in the least degree transformed into waves of transla- 
tion. 

It may be observed that the fact that when the sea-bottom 
slopes gently from the water-margin the sand is often covered with 
symmetrical ripples, or ripples with their anterior and posterior 
slopes equally inclined, from the vicinity of the plunging line to a 
depth as great as the eye can distinguish them, is sufficient proof 
that the currents that formed them were evenly balanced. 

As the question of the formation of ripple-mark is important, 
as. bearing on the subject of the present Paper, I take this oppor- 
tunity of calling attention to the valuable Papers of Monsieur C. de 
Candolle, Professor F. A. Forel, and of Dr. G. H. Darwin, published 
respectively in the Archives des Sciences, and in the Proceedings of the 
Royal Society, allin the year 1883. But I would more especially refer 
to two earlier notices of observations by Professor Forel in the Bulletin 
de la Société Vaudoise des Sciences Naturelles for February and March, 
1878. Inthe earliest of these notices Professor Forel points out how 
the shape of sand-ripples formed by waves in the currentless waters 
of lakes differs from that of ripples formed by running streams. 
This was one of the points I endeavoured to establish in 
1882, in ignorance of the prior published observations of Pro- 
fessor Forel. 

The currents set up by a wave plunging on the shore are more 
difficult to make out than those hitherto considered. Their sequence 
seems to be as follows, viz. :— 


Hunt—On the Action of Waves on Sea-beaches, &c. 263 


(1). A flow of water from the margin of repose to meet the ad- 
vancing wave-crest. 

(2). A return of the water to the margin of repose. 

(3). A flow up the beach above the level of repose. 

(4). A return to the said level from the point of furthest reach. 

Numbers (1) and (2) seem to be the equivalents of the ordinary 
primary and secondary wave-currents, whilst (8) and (4) seem to 
represent the amount of wave force that has not been expended in 
the plunge on the bottom. 

So far as their action on the beach is concerned, numbers (2) 
and (3) combined may be regarded as forming one current from 
the plunging point to that of furthest reach ; and numbers (1) and 
(4) as forming one current from the point of furthest reach to that 
of plunging. 

The flow of water down a beach is occasionally spoken of as 
though it were the recoil of a wave that had previously broken on 
the shore, whereas the united downward current must be referred to 
two waves, the lower portion to the approaching wave, the upper 
portion to the one that has preceded it. 

I shall endeavour to show that in their action on beach- 
material these combined forward and backward currents are nicely 
balanced. 

I shall approach this part of my subject by a description of 
some observations made on the beach at Oddicombhe, in Babbicombe 
Bay, South Devon. 

This beach is well suited for observations on the action of 

waves free from tidal complications, as, owing to its position in a 
sheltered inlet in the north-western shores of Lyme Bay, it is 
protected from all strong tidal currents. It is exposed to heavy 
seas from only one quarter, viz. between E.S.H. ¢ E., and 8.8.H. 3 EH. 
When the wind blows from any other direction, it is either off-shore, 
or blows off the land between Oddicombe and Portland, with a 
maximum drift of about 40 miles. In the case of an H.S. H. wind 
the drift is about 191 nautical miles. The general trend of the 
beach is about N.N.H. and 8.8. W. 

The following table will indicate the winds to which one part or 
another is exposed, with their corresponding drifts, in nautical miles. 
It will be seen that the E.S. E. wind, with the long drift of 191 
miles, blows dead on shore. The winds blowing from any point 


264 Scientific Proceedings, Royal Dublin Society. 
south of H.S.E. (if they impinge on the beach at all) will tend 


to drive the shingle to the north, and vice versa. In every case 
winds impinging on the beach from the southward have longer 
drifts than those impinging on it from the northward :— 


Direction of wind. Drift in ‘Dinos era Of nl Drift in 
Bearings all magnetic. miles. | miles. 
N.E. by N. 5 E.S.E. i E. | 40 
N.E. 8 E.S.E. (eH 
N.E. by E. 9 S.E. by E. 153 
K.N.E. 20 S.E. 150 
E. by N. 28 S.E. by S. 85 
E. 34 §.S.E. } E. 68 
E. by §. 39 


In the course of the autumn of 1882 I made a series of obser- 
vations at Oddicombe, roughly measuring the strand on each 
occasion, and noting the change in the shingle-ridges. At the ex- 
treme north-eastern end a cove is partially divided off from the 
main beach by some large isolated rocks, and in this cove the strand 
was always composed of shingle (chiefly limestone), extending from 
low-water mark to the foot of the cliffs, which cliffs bound the 
beach on the land side, and are only reached by the water in 
exceptional gales. For the purpose of measuring the strand in 
this cove, on the 14th October, 1882, I placed together three of 
the largest beach-stones I could find, just above the reach of the 
waves. ‘The tide was low and on the turn, and the waves, during 
the time the level of repose of the water was stationary, had ac- 
cumulated a ridge, or bank, of small stones. On completing my 
measurements, I found that with the rising tide the waves had 
struck my three mark-stones, and that they were now in line, one 
behind another. Thinking it a good opportunity to observe the 
action of waves on shingle of different sizes, I stood, watch in hand, 
to record their action on these three mark-stones. In three minutes 
the first stone (the one nearest the sea) had fallen down the slope 


Hunt—On the Action of Waves on Sea-beaches, &c. 265 


seawards, the other two being nearly covered up with small stones; 
in another two minutes number two (the middle one) was carried 
seawards by a rather heavier wave than usual, whilst number three 
was nearly out of sight, covered up; in another minute and a-half 
number three was quite covered up; in two minutes and a-half 
more, number three was beginning to uncover; in another two 
minutes it was bare on the face of the slope (not on its summit) ; 
in half a minute more it started downwards, and finally, in three 
minutes more, had travelled so far seawards as to be lost to sight. 
Thus, in the space of fifteen minutes and a-half, my three mark- 
stones were carried away by the waves; one of them having been 
in the meantime entirely, and another partially, covered with 
small stones. ‘The following note was made on the spot :—‘ The 
stones carried away, about 4 or 5 inches long. About 10 yards 
to eastward, by side of cove, waves not breaking heavily, and not 
making a ridge, or assorting the stones. The waves, at the point I 
have been observing, are driving up a ridge of small stones; query, 
what will they do when they get to the slope of large shingle behind 
them ? Will they drive them (the stones) up the beach, or level the 
ridge? I placed the largest stone I could lay hands on as a mark, 
and the ridge passed clean over it, and at 2.20 the stone was 
carried away seawards by the undertow. ‘The ridge now consists 
of much bigger stones; . . . to-day, the waves, being very moderate, 
were carrying the smaller stones up the beach. Wind wasS. E., 
light. It is interesting to observe that, though the weather has 
been so quiet lately, the small waves have been able completely to 
demolish any neap-tide ridge: the pebbles forming one sweep from 
high-water mark to low-water mark to-day.” 

“20th Oct. (Neap tides.) In little cove at east end a bank of 
small stones, very steep, at and above to-day’s water-line; thence 
downwards, big beach stones; the dividing line very sharply 
defined.” 

28th Oct. (Spring tides.) Strong N.E. wind; strand, 42 
yards ; all previous ridges gone, within the distance.” 

“4th Nov. (Neap tides.) Neap ridge quite new since I was 
last here.” 

“14th Nov. (Spring tides.) It having blown hard from 8S. E. 
to N. H. yesterday, 1 went to Oddicombe this afternoon. Found 
all ridges swept away, except the highest of last winter... .. 


266 Scientific Proceedings, Royal Dublin Society. 


I observed at the east cove, for the first time, that when a wave 
breaks, and rushes up the beach, the wave-current turns to meet 
the next wave, towards the sea, long before the advanced portion 
ceases to flow onward, so that the forward current actually divides 
into two, one going up and the other down the strand..... By 
the turn of the tide, about 2.30, a steep ridge had been formed 
between three and four feet high, close to (the) western rock bound- 
ing the little cove. Small stones were shot up and over this ridge, 
and big ones pulled down.” 

The observations made on the 14th Oct. and 14th Nov. seem 
to afford a solution of the problem as to the relative destructive 
and accumulative actions of waves on shingle-beaches, and they 
reconcile the apparently inconsistent observations of Mr. Palmer 
and Sir John Coode. Itis clear that the destructive and accumula- 
tive actions may be going on at the same time. As a matter of 
fact, they were both going on together on the days referred to, on 
which occasions the waves were accumulating small stones, while 
denuding the beach of large ones. I shall presently show how at 
other times waves will reverse this action, accumulating the large 
stones while carrying off the small ones. 

It is important to note that whilst the plunging waves, observed 
on the 14th October, were driving forward the small stones and 
drawing back the large ones, at a distance of a few yards waves 
that, for some reason, were not breaking so heavily, were not assort- 
ing the beach-stones in the same way. 

The action of the plunge of a wave in accumulating beach- 
material can be conveniently studied when very small waves are 
breaking on a sandy beach, and the sea is not disturbed by swells. 
It will,be seen that the plunge stirs up the sand at the starting- 
point of the forward current, and that some of this sand is carried 
forward by the water in suspension. On the turn of the current 
there is a moment of slack water, during which time the sand falls 
to the bottom, whence it is not readily dislodged by the return 
current, commencing as it does gradually, with no preliminary 
plunge. Inthe case under consideration, should the sand be mixed 
with mud, the latter, having no time to settle on the turn of the 
water, is carried backwards as well as forwards in a state of 
suspension. Now, it is only necessary for us to transform our 
summer: wavelets by gradual stages into storm waves, for us to 


Hunr—On the Action of Waves on Sea-beaches, &c. 267 


find our fine sand replaced by coarse sand and stones, up to the 
largest masses the waves can carry forward; whilst at the same 
time our mud will be replaced by sand, and stones sufficiently 
small to remain within the grasp of the water. 

So far we have seen that the plunge, by supplementing the 
action of the forward current, causes the latter to accumulate sand 
or stones in front of it; in other words, to form a sloping beach. 
But the moment a slope is formed, an opposite or counteracting 
force is brought into play, viz. gravity, which gravity will tend to 
cause the accumulated material to roll seaward again. We thus 
see that the beach-slope, so far as we have considered it, is a com- 
promise between the action of the plunge tending towards the 
piling up of the beach-material, and the action of gravity which 
tends to pullit down, the agents being the forward current + plunge, 
on the one side, versus the backward current + gravity on the other. 
This is practically the normal state of things on a flat, sandy 
beach, where the sand is fine and easily saturated. Where the 
sand is coarse, or the beach-material is shingle, another factor in 
beach-making is brought into play, viz. the absorption by the shingle 
of the whole or a portion of the water of the backward current above 
the level of repose for the time being. In this case we may consider 
the forces acting on the beach above the level of repose to be :—The 
forward current + plunge, versus the backward current + gravity 
— absorption ; or, the forward current + plunge + absorption, versus 
the backward current + gravity. 

It will be noted that the absorptive power of the shingle in- 
creases gradually from the margin of repose, where it is nil, owing 
to the shingle being saturated, to the point of furthest reach, where 
it may be perfect; and that absorption alone would suffice to ac- 
count for a gradually increasiug curve in the profile of a beach 
above the margin of repose. Such a curved profile is often present 
at and above high-water mark, where the waves attack the shingle 
at or about the same level for an appreciable time at the turn of 
the tide; and more especially is it a feature of spring and neap 
tides, at both of which times there is not much difference in the high 
water-level for several successive tides. So far as my observations 
go, this absorptive action on the part of the beach-material is 
essential for the formation of the phenomena known as “ Fulls,” 
“Ridges,” and “ Sets-off.”” With absorption these will occa- 


268 Scientific Proceedings, Royal Dublin Society. 


sionally be present whether the beach be coarse sand or shingle; 
without absorption there can be none. 

In the cases we have been considering, the beach-material has 
been treated as though homogeneous as to size, form, and specific 
gravity, a state of things that can never obtain in the case of shingle 
beaches, whose component pebbles usually vary much in size and 
character. 

Tt will be at once apparent, that the conditions prevailing above 
and below the margin of repose will differently affect stones that 
differ in size, form, and weight. The stone that can climb to the foot 
of the slope that rises so rapidly above the margin of repose may 
fail in getting higher, whereas a smaller stone, retained in the 
grasp of the water, on the lesser slope below, may be light enough 
to mount the steeper incline, and remain there when assisted to 
do so by the diminution in strength of the backward current by 
absorption. Asa matter of fact, it 1s not uncommon to find the 
pebbles composing the steep bank above the high-water margin of 
repose for the day smaller than those on the strand below. I have 
already mentioned one instance of this at Oddicombe during neap 
tides, on the 20th October, 1882; and I find, on reference to my 
note-book, that the bank of shingle, formed, or re-formed, by the 
spring tide of October 14th, at Babbicombe, consisted of finer 
shingle than that on the strand immediately below it. Similar 
instances could be multiplied. On the other hand, it would be 
easy to find cases in which, from exceptional causes, the shingle 
below a bank was smaller than that composing the bank. 

The form and specific gravity of shingle affects its distribution 
by the waves. To take them separately :—It is evident that were 
the waves to wash a number of pence and bullets up asmooth rock 
slope, on which the pence could rest and the bullets could not, in 
course of time all the pence would be found high up on the slope, 
whilst all the bullets would be collected at the bottom. In the 
case of beaches where the shingle is partly derived from slate- 
rock and partly from limestone it is a common thing to find the flat 
shingle at higher levels than the more spherical. Similarly, on 
sandy beaches, slate shingle will work its way up the strand by 
virtue of its superior powers of anchoring itself on the turn of the 
current. 

Sir John Coode has noticed this fact in connexion with the 


Hunt—On the Action of Waves on Sea-beaches, &c. 269 


Chesil Bank. He writes, ‘‘ It is remarkable, that the large shingle 
found at about the level of high-water, and such of the large pebbles 
as may occasionally be found at higher levels upon the Bank, have 
generally a flatter form than those under water. It is important 
to notice, that all the shingle near Portland is generally less 
spherical than that at some distance to the westward, as this proves 
that it has been longer exposed to the grinding action of the sea.” 
(C. 21.) As this segregation of shingle according to form is a 
common beach phenomenon, it seems possible that the difference in 
the flatness of the Chesil shingle may arise from difference of form 
in the rock-fragments from which the shingle was originally derived. 
IT am not aware that it has been shown that wave-action tends to 
grind spherical shingle flat ; and there is no doubt that spheroiia 
forms are found in very small shingle. 

The effect of specific gravity in influencing distribution I have 
seen well exemplified in the case of some fine metallic sand collected 
by the waves at the highest level in one of the coves in Torbay. 
In this instance the highest and lowest deposits were fine sands, the 
intermediate expanse of tidal strand being rocky, with some shingle. 
I may here point out how likely these exceptional cases are to per- 
plex the student of wave-action. In my own case, after having 
studied beaches for many months, and taken a large series of photo- 
graphs, I came across a beach in Mudstone Bay, near Berry Head, 
which seemed to falsify many of my conclusions. Spherical and 
flat shingle of all sizes was intermixed with sand in hopeless con- 
fusion. The explanation was to be found in the surrounding 
rocks, consisting as they do of limestone, slate, and hematite. 
Shingle derived from such sources naturally differed much both in 
form and specific gravity. The slate had the advantage in form, 
the hematite in weight, and the result was that the flat slate 
shingle and the spheroidal hematite shingle were evenly matched 
in their competition for highest place. 

We have now briefly considered the effect of waves of different 
sizes on shingle of different form and specific gravity, but have 
taken no account of the rise and fall of the tide. Unless the weekly 
variation in levels, owing to spring-tides and neaps, and the daily 
variation in levels at high-water and low-water be taken into 
consideration, some of the commonest beach phenomena may seem 
paradoxical. 


270 Scientific Proceedings, Royal Dublin Society. 


Tt is not an uncommon thing to find a beach after a gale covered © 
with fine shingle at the higher levels; and again, after another 
gale of apparently equal severity, to find the same area covered 
with shingle many times larger in size. For example :—Let Oddi- 
combe beach, during spring-tides, be visited by a heavy gale from 
the eastward. It will be seen from the table that the sea-drift will 
be about forty miles, and that the waves will in consequence be 
comparatively short and powerless. The waves will only throw up 
the smaller class of shingle; but will throw such shingle to a high 
level, on account of the height of the tide. A week later, at neap- 
tides, let the same beach be visited by another gale of equal violence 
from the south-eastward. The sea-drift will be about 150 miles. 
The waves will be much larger; they will consequently be able to 
cast up larger shingle than the waves of the preceding week, and to 
east it further. Should the waves of the second gale overreach 
those of the first, the work of the first will be obliterated; should 
they just fail to reach them, the result will be that at the higher 
levels the small shingle will be above, or more remote from, the sea 
than the large shingle. Reverse the order of events. Let the neap- 
tide gale from the south-east precede the spring-tide gale from the 
east. The relative positions of the large and small shingle will 
now be reversed. ‘The large will now be more remote from the sea 
than the small. 

A somewhat analogous distribution of shingle may arise from 
heavy waves at low-water reaching as far as smaller waves at high- 


water. 
Mr. Kinahan has stated that on the east coast of Ireland 


“‘ oround-swells due to 8. W. and W. winds have intervals of one, 
two, five, or more minutes between them, and are much larger than 
the ordinary wind waves, or the tidal waves, which may be break- 
ing at the same time, rise much higher on the beach, and often at 
one sweep carry away a mass of materials that it has taken a number 
of small wayes to pile up ”—( Travelling of Sea-beaches, loc. cit. p. 5.) I 
have hitherto avoided the use of the term “ground-swell,” owing to 
the difficulty of ascertaining its precise meaning. Mr. Russell has 
defined a ground-swell as a wave that is the result, or consequence, 
of the action of the wind, but which has ceased to be under the in- 
fluence of the wind (R. 53), and speaks of “the long, low swell, the 
residue and telegraph of some distant storm”—(Trans. Brit. Assoc., 


Hunt—On the Action of Waves on Sea-beaches, &c. 271 


1837, p. 448). Mr. Kinahan has defined a ground-swell as a wave 
generated in the Atlantic or Channel, as distinguished from a wave 
due to the winds blowing directly on the coast—( Travelling of 
Sea-beaches, loc. cit. p. 3). 

Mr. (now Sir James) Douglass has referred the travel of shingle 
to the ocean wave, or ground-swell (P. 45). 

Mr. EK. Wynne describes Portland as exposed to the full swell 
of the Atlantic rollers, and considers the said Atlantic rollers might 
be transformed into waves of translation in the Channel (P. 47). 

If the ground-swell be the offspring of a wave of oscillation, it 
is difficult to see how it is to be distinguished from the ordinary 
swell, whose action on a beach we have been considering. Nor is 
it easy to see how it can exert more power than its parent wave. 
The term conveys the impression that an ordinary swell is meant, 
travelling in water shallow enough for it to feel the bottom; but I 
can find no such definition of it. The term is often vaguely under- 
stood, which I perceived when an intelligent man described to me 
the effect on the sea-bottom of an “under-ground swell.” 

It may be noted, that Mr. Kinahan’s long waves of irregular 
period cannot be ordinary swells resulting from oscillating wind- 
waves, as their periods are too long and irregular. A few years ago, 
at one of the British Association lectures, it was confidently asserted, 
that any wave with a period exceeding twenty seconds must be at- 
tributed to some other cause than an ordinary wind-wave. 

Many observers, whilst watching the tide rising on the sea- 
shore during stormy weather, must have been surprised to note the 
long time that occasionally elapses before the waves reach a given 
point on the beach a second time. Thinking to observe the rise 
and fall of irregular waves of this sort best by the currents set up 
by them in the mouth of an artificial harbour, I made the following 
observations on February 2nd, 1883, in the mouth of the old har- 
bour at Torquay. 

The following is the substance of my notes :— 

On the night of Feb. Ist it blew a heavy gale from the southward. 
On Feb. 2nd I went to the Old Pier Head to observe if there were 
any “run” in and out of the harbour. I moored a piece of wood 
about five inches long to a stone, sunk in the harbour’s mouth, by a 
line sufficiently long to allow the wood to pass freely through the 
space of several yards on the surface of the water. High-water 


a12 


at 1». 30™. p.m. 
1D Bey 


time. 


Scientific Proceedings, Royal Dublin Society. 


My observations lasted from 12. 6™. 305. to 


So tide rising and flowing into the harbour the whole 


Wind fresh, right into harbour’s mouth (W. by N., over 
less than one mile of water). The following table gives the times 
when the currents commenced to flow in and out of the harbour :— 


| Direction in which the 
Time. current commenced Remarks. 
to flow. 
JED Gy (Sh 
I @ ao Out. 
1 i 78) In. Ran the wood under water. 
1° 9 6 Out. Ran the wood under water. 
1B til @ In. 
19 18 7B Out. Sluggish. 
L204, 0 In. 
j Very strong. Ran the wood under 
12 16 Out. erates 
12 16 30 In. Strong. Ran the wood under water. 
12) 1830 Out. Strong. Ranthe wood under water. 
Ran the wood under for 1™. 405., 
12 19K N30 ba, with an occasional momentary 
re-appearance. 
19) 933 (0) Out. Ran the wood under. 
12° 24 30 In. Very sluggish. 
IY B® Out. Very sluggish. 
12} Of 8) In. Very sluggish. 
1229) 30 Out. 
1 Bil © In. Strong. Ran the wood under for 30 §. 
Very strong. Ran the wood under 
1D 8 76 Out. for 1™. 58., without its re- 
appearing for a moment. 
( A long, steady flow, beginning 
12 34 75 Tn. sluggishly, and then rimning the 
| wood down for a long time. 
1 Bes Out. 


Hunt—On the Action of Waves on Sea-beaches, §c. 278 


We have here eighteen full currents in 31:50 minutes, giving the 
average duration of each current as 1°75 minutes, and thea verage 
interval between the waves 3:50 minutes. The outrushes quite ob- 
literated any in-current on the surface due to the wind and rising 
tide. 

These observations made in the harbour harmonize with another 
set made at Oddicombe on the 4th of November previous. Wind 
N.W.; very strong off shore. ‘Tide, neaps. Nearly high-water. 
Beach-slope steep. Sea surging up and down some two or three 
feet vertical, yet not breaking on the shingle. The run on the 
beach seemed rather owing to the water surging backwards and for- 
wards than to any very definite swells, though swells could be dis- 
tinguished sometimes. The water-mark against the eastern rocks 
seemed nearly three feet between rise and fall; but the change of 
level caused no break on the beach continually. In this case we 
see that waves of some kind, some three feet in vertical height be- 
tween trough and crest, were rolling in upon the beach; but, not- 
withstanding their considerable height, the rise and fall of the 
water was so gradual that there was no break or plunge. It will 
be seen at once that the plunge being a potent auxiliary of the for- 
ward current in the accumulation of shingle, and its loss to the 
forward current being equivalent to a corresponding gain to the 
backward current, if in any case an accumulation of shingle has been 
in progress under the action of plunging waves, the occasional inter- 
vention of non-plunging waves of equal or greater power must tend 
towards the removal of such accumulated shingle. 

The question arises, what is the cause of these irregular waves 
of long period ? It seems probable that they result from the dis- 
turbance of the equilibrium of the water by wind pressure, whereby 
the water is unduly raised at one point and lowered at another. 
This phenomenon is well observed in narrow straits between two 
seas, such as the Kattegat, the Straits of Dover, and the Bos- 
phorus. 

In the Kattegat, according to Vice-Admiral Zhartmann (quoted 
by Mr. Thomas Stevenson), ‘where the tides have a velocity of 
1 to 2 knots, and the common rise is one foot, ‘the currents may 
sometimes, in boisterous weather, continue to run for three weeks 
the same way, and even to attain the velocity of four knots; and in 
a furious gale of wind, on the 15th of January, 1818, the water rose 


SCIEN. PROC. R.D.S.—VOL. IV. PT. VI. 2C 


214 Scientific Proceedings, Royal Dublin Society. 


53 feet above the common water-stand.’ He also mentions that in 
the Great Belt the velocity is increased in south-east storms from one 
or two knots to five knots in the narrowsof Hasselo, and that northand 
west winds produce similar effects in the Sound; and he adds, ‘ Nor 
is it necessary to this result that the last-named winds should blow 
home: it is enough that a gale should have swept across the North 
Sea in that direction for several successive days.’ ”’—(Stevenson on 
Harbours, p. 77.) 

Major Rennell attributed the loss of “‘ the Britannia East India 
Ship” on the Goodwin Sands to “a current produced by the run- 
ning off of the accumulated waters; a violent gale from the west- 
ward then prevailing.” —(Phil. Trans., 1809, p. 400.) 

The currents on the Bosphorus are described as follows by a 
naval correspondent of Zhe Times :—‘“'The main current of the 
Bosphorus (which) has a strength varying from four to two miles 
per hour, according to the state of the weather. .... When a strong 
north-east wind is blowing, .... the main stream runsata greater 
rate even than the average of four miles previously stated. With 
a wind from the south, a great change takes place, the course of the 
current from the Black Sea is checked, and frequently overcome by 
one at the surface running up.”—(‘‘ Torpedo Experiments on the 
Bosphorus,” The Times, 27th December, 1882.) 

These instances may suffice to prove that violent winds have the 
power of piling up the water before them, and of giving rise to 
strong currents. If, however, a body of water, at any point in the 
sea, is thus maintained at a height above the normal level, it is only 
requisite for the restraining pressure to be suddenly removed, or for 
the pressure to be irregular, for a wave of translation to be 
generated by nature in a manner analogous to that adopted by 
Mr. Russell in his experimental reservoir. This reservoir Mr. Rus- 
sell describes as being twenty feet long, having an additional length 
of 73 inches reserved to form a generating chamber. “By filling 
the generating reservoir with water to a higher level than the ex- 
perimental reservoir, while the sluice was closed, on raising it the 
water descended, producing a wave of which the volume was known.” 
—(TZrans. Brit. Assoc., vol. vi., p. 439.) 

In nature the accumulated water could be released either by a 
sudden decrease in the force of the wind or by a change in its 
direction. Both these conditions are present in storms when the 


Hunt—On the Action of Waves on Sea-beaches, &e. 275 


wind blows in squalls, and either veers or backs. Assuming, then, 
that by variation in the wind-pressure waves of translation are 
generated at sea, and thence travel to the shore, it is of importance 
to ascertain the form under which they reach the shore. Do they 
continue to be waves of Mr. Russell’s first order, or are they wholly 
or partially transformed into waves of his second order? On the 
reply to this question depends the action which they will exert on the 
beach, and the point at which they will plunge, if they plunge at all. 

In a Paper read before the Royal Society, Dr. Rankine writes 
as follows :—“It is known that in deep water all waves left free 
from the action of disturbing forces tend ultimately to assume 
the condition of free rolling waves, whose velocity of advance de- 
pends on their periodic time..... It follows that, if a wave is 
raised through the disturbance produced by a solid body, that wave 
will at first travel with a speed depending on the virtual depth 
of the original disturbance; but as it advances to a greater and 
greater distance from the disturbing body, the velocity of advance 
will gradually approximate to the terminal velocity corresponding 
to the periodic time.” —(Phil. Mag., vol. xxxvi., p. 55.) According 
to Dr. Rankine it would seem that a wave of the first order, a wave 
of translation, may be gradually transformed into a wave of the 
second order, whose velocity corresponds with its period. A good 
opportunity of putting this theory to the test presented itself on the 
occasion of the Torquay regatta of 1883. The wind was fresh from 
the westward, off shore. ‘The yachts had to round a mark-boat in 
smooth water, about half a mile off Saltern Cove, in the bight of 
the bay. Vessels of fifty tons and over in rounding this mark-boat 
generated waves sufficiently large to toss about the six-ton boat in 
which I was sailing. It seemed a good opportunity to observe the 
character of these waves when they reached the shore after travers- 
ing the half mile of smooth water betwixt the mark-boat and 
Saltern Cove. The water being smooth there was no doubt as to 
the exact position of the margin of repose. ‘The large waves 
generated by the yachts plunged on the beach below, or seawards 
of the margin of repose, and must therefore have undergone, at 
least partially, transformation into waves of the second order; 
unless, indeed, it be contended that they were analogous to Mr. 
Russell’s negative waves of the first order, which, however, seems 
hardly possible. 


22 


276 Scientific Proceedings, Royal Dublin Society. 


It may be observed, that Sir George Airy instances the follow- 
ing example of a negative wave :—“ 'The phenomenon of a negative 
wave is given in great perfection by the paddles of a steam-boat: 
the first wave which passes away from it being a hollow of consider- 
able depth. We were first made aware of this by observation of 
the traces made by Mr. Bunt’s excellent self-registering tide- 
gauge on the banks of the Avon, at a short distance below Bristol. 
....—(Tides and Waves, 398.) It may be worth noting, that 
the waves generated by a bluff-bowed paddle-steamer of the old 
type are very complicated. While the paddles are making one set 
on either side, the bows of the vessel are throwing off another set 
on either side. The latter would resemble those thrown off by a 
sailing vessel, being independent of the cause of motion, whether 
steam or wind. The bow-waves being generated in advance of the 
paddle-waves would precede them to the shore; at any rate, in the 
case of so narrow a river as the Avon. It seems possible that the 
traces in question may have been the records of a positive wave of 
translation, partially or wholly transformed into a free rolling wave 
in its passage to the river’s bank. 

It would appear that waves generated by the general equili- 
brium of the water being disturbed by wind-pressure will reach the 
shore as waves of translation, subject to modification, if the dis- 
turbance takes place at a sufficient distance from the shore. . Their 
peculiar action on the beach will depend on the extent to which 
they plunge. I have said that, on November 4th, 1882, a vertical 
rise and fall of the water-level to the extent of nearly three feet 
caused no break on the shingle at the point I was observing at 
Oddicombe. <A simple backwards and forwards swing of the water 
of this character, however caused, cannot fail to cut out material 
accumulated by previous plunging waves. On a subsequent oc- 
casion, I made the following note :—Oddicombe, 25th Nov., 1888. 
“Wind off shore. Disturbed swell cutting out the beach. Angle 
of one pebble slope 41°, of another 41°; both in the small cove. 
This was the maximum angle of repose, as an umbrella drawn 
lightly across the face of the slopes set the pebbles freely in motion. 
Moreover, the swells surging up would set dry pebbles free high up 
the slope I was observing.” The two pebble slopes referred to 
were not curved, their profiles being perfectly straight; and they 
were clearly ridges or banks of denudation, and not of accumulation. 


Hunt—On the Action of Waves on Sea-beaches, &c.. 277 


In our consideration hitherto of the action of waves running 
on to beaches at rightangles to their trend, we have noticed the 
various effects produced by swells of different sizes and characters 
on beach-material of different size, form, and specific gravity ; and 
have seen how greatly the distribution of the beach-material by 
the waves is affected by the tidal variation in the sea-level. It 
would seem that ordinary waves, acting on mixed beach-material 
on a tidal strand, would be sufficient of themselves to form the 
peculiar beaches described by Mr. Price, where the high-water 
ridges are separated from large stones lower down by zones of peb- 
bles, gravel, and coarse sand.—(See R., 57.) 

In the ordinary case of waves rolling on a beach under the in- 
fluence of wind, the action of the wave-currents are complicated by 
currents set up by the wind-pressure on the surface of the water. 
It is impossible to overrate the importance of the latter currents, as 
they frequently overpower and obliterate the normal tidal currents 
of the locality. Prof. J. D. Dana says, that “ the forcing of water 
into bays, whether by regular winds or by storms, causes a strong 
under-current outward, like that from the tides. This happens 
when the entrance of the bay is broad, so as to allow of an in-flow 
over a wide area, while the deep-water channel is narrow..... — 
(Man. Geol., 3 ed., p. 671.) It will be easy to show that under 
other circumstances the result will be different. Prima facie it is 
probable that the surface-water will leave the bay at the point, or 
points, where it will encounter least resistance, whether at the sides 
or centre, at the bottom or surface, or at two or more of these 
together. The following instances in the case of Torbay are in- 
structive :— 


On January 7th, 1883, during a strong 8. W. gale, I found — 
that there was a strong inward surface-current in the mouth of 
Torquay Harbour (tidal), although the tide was half-ebb. Feeling 
sure that under the circumstances there must be a strong under- 
current outwards, I tied stones to a couple of net-corks, with strings 
about six and eight feet long respectively. On these being thrown 
into the water, the corks were carried seaward in the teeth of the 
gale, though in squalls it was blowing furiously. The stones, 
though small enough not to submerge the corks, offered sufficient 
resistance to the outgoing under-current to tow the corks out of 


278 Scientific Proceedings, Royal Dublin Society. 


the harbour. There was no “run” in and out of the harbour, as 
on the Ist February, but there were two contemporaneous opposite 
currents at different levels, the upper one flowing in under wind 
pressure, the lower one flowing out. Though the tide was ebbing, 
the current, in the case of so small a harbour, ascribable to that 
cause. would be comparatively insignificant. 

On Oct. 19th, 1882, Mr. William Browne, boatman, of 'Tor- 
quay, informed me that he had nearly lost his ecutter-yacht 
“ Lapwing ”’ during the southerly breeze of the preceding night, as 
she had broken from her moorings, and only been recovered by the 
coastguard as she was going round the New Pier. On pointing 
out that the yacht must have been going in the teeth of wind and 
wave, my informant said it was so, and attributed the occurrence to 
an eddy. As, however, the tidal current at the spot indicated is 
very feeble, I have no doubt the yacht was under the influence of a 
strong wind-raised current, working seawards, under the lee of the 
pier. Mr. W. M. Baynes has favoured me with the following 
note :-—‘* Jan. 10, 1884. With reference to the undertow in Tor-: 
quay harbour, [ remember watching, about two years ago, what 
appeared to be a ship’s boatfull of water, her gunwales being just 
awash, slowly travelling from the old pier head across the new har- 
bour in the teeth of a strong south-easterly wind. I think she 
fouled two or three moored vessels, and, on being pushed clear, de- 
terminedly resumed her windward course.”’ 

The above cases illustrate the action of wind-raised currents in 
a tidal harbour, and in one of the minor inlets of Torbay. ‘Torbay 
itself affords another instance on a larger scale. This bay may be 
described as a rectangular inlet, some four and a-half miles wide at 
the mouth, and about three miles deep from mouth to bight. In 
the bight of the bay the bottom slopes seawards very gently for 
about a mile, when a maximum depth of six fathoms at low-water 
is attamed, and this depth remains constant over several square 
miles in the centre of the bay. Easterly winds blow into the bay, 
and raise the sea. Those from the westward are smooth-water 
winds, being off shore. Hasterly winds are the only ones that can 
affect the bottom of the bay by either wave-currents or wind-raised 
currents.. During the more than eleven years in which I have taken 
notes bearing on the action of waves and currents on the bottom of 
Torbay, I have been much perplexed by the apparent inconsistency 


Hunt—On the Action of Waves on Sea-beaches, &c. 219 


of my observations. Many of these observations, I may remark, bore 
upon the currents only incidentally, having more especial reference 
tothe occurence and habitats of uncommon shells. One of these shells 
(thracia convexa), so far as I can ascertain, has only been taken in 
Torbay alive in one limited locality, viz. off Daddy Hole Plain, 
on the northern shore. The living mollusc of this species burrows 
deeply, and is rarely disturbed; but the dead shell, being light, is 
eminently calculated to be drifted by currents. If, however, this 
species lives in but one spot in Torbay, as appears to be the case, the 
occurrence of its shells in the neighbourhood will be a guide to the 
nature of the currents that affect the bottom. Sundry notes that 
bear on these currents are collected in an appendix. They may be 
summarised as follows :— 

(1). Shells are occasionally swept from off Daddy Hole to 
Paignton, in a westerly direction. . They are occasionally swept 
from Daddy Hole to a point off the Orestone, in an easterly direc- 
tion. 

(2). Refuse from the gas-works, and fragments of peat, and 
masses of seaweed from Torre Abbey, will occasionally find their 
way to Daddy Hole from the north-westward. Shells and stones 
will occasionally reach the same spot from the eastward. 

(3). One easterly gale will disturb shells living in the ground 
off Daddy Hole, but not carry them off; another gale of seemingly 
equal intensity will sweep the whole bottom bare. One gale, or a 
succession of gales, will roll and kill thousands of cockles off Paign- 
ton, without driving them on shore; another gale will send them 
on shore, and sweep the bottom so clean, that nota valve of cockle 
will be forthcoming in the usual localities. 

(4). A heavy on-shore wind will drive shells on to the beach at 
Paignton; an equally strong on-shore wind at Meadfoot rarely 
throws up any: though within a few hundred yards of the latter 
beach (west of the sea-wall) dead shells collect on the bottom off 
Daddy Hole in quantity. Among the latter are occasionally found 
limpet shells, which have probably come from the shore (the alterna- 
tive points of derivation being outlying islets), and beach-shingle 
that must have come from the shore. 

(5). A strong easterly wind usually reverses the normal inflow of 
the ebb-tide along the northern shore of Torbay, but occasionally 
seems to intensify such inflow, 


280 Scientific Proceedings, Royal Dublin Society. 


I may instance one extraordinary case of a heavy object being 
carried away seaward in the teeth of the waves. Some years ago 
the heavy wood and iron door of the sewer outfall at Torre Abbey 
was trawled up by a Torquay fisherman, Enoch Stockman, off 
Meadfoot Sands, and towed back to Torquay. The incident came 
under my notice, as Samuel Stockman was dredging with me at the 
time, and called my attention to his son having got hold of some- 
thing heavy. Having asked Enoch Stockman to let me have his own 
account in writing, he has sent me the following note :—“ I cannot 
tell how many years ago, I cannot tell in what month, I caught the 
shout (sic). I believe the Great Rock was a sail breadth open in 
the Thatcher. We were just abreast of the sinker, shagstone 
drawing inside Dyer’s quarry.” The important facts are that 
Stockman trawled the “shout,” which he estimated at some seven 
feet square, from the bottom of the sea, some 2500 yards from its 
point of derivation. The average course followed by the outfall 
door to the point where it was trawled was from about N. W. to 8. H. 
The waves that set it in motion must assuredly have come in from 
about the opposite direction. 

The observations recorded above indicate bottom currents in 
Torbay that vary greatly in direction. I venture to suggest that 
such currents may be caused by wind-formed currents in the 
English Channel of varying depth and intensity. Winds from any 
point north of H. by S. have a sea-drift before striking the mouth 
of Torbay, of about 40 miles and under. Winds from any point 
between EH. by S. and 8.H. have a drift of 145 to 190 miles. 

Thus, two easterly gales of equal intensity will be accompanied 
by currents of short or long drift, according as they blow from 
points north of E. or south of H. The gale with the longest sea- 
drift will create a deeper current than that with the shorter drift, 
both on account of the greater time during which it acts on the 
water, and on account of the heavier seas raised in the greater dis- 
tance traversed by the wind, the deeper wave-hollow allowing the 
wind to act on the water at a greater depth below the level of re- 
pose. Now, it is clear that the depth of a current entering a bay 
is of great importance in respect to the action brought to bear on 
an object lying on the bottom. If such a current be deep enough 
to affect the bottom directly, the motion imparted to the object will . 
be in the direction of the main current; but if the current be not 


Hunt—On the Action of Waves on Sea-beaches, &c. 281 


deep enough to reach the bottom, but passes over it as a surface 
current, the object will escape any direct action, and may even be 
impelled in a direction contrary to that of the main current by an 
under-current moving seawards, to balance the main surface-current, 
moving shorewards. Thus the difference of a few feet in the depth 
of a current may make all the difference in the direction in which 
a light object on the bottom may travel under its influence. 

The action of the waves on shells, such as the cockles already 
referred to off Paignton, lying, as the latter occasionally do, in six- 
fathom water, at the foot of the slope rising towards the shore, 
would naturally be much affected by the depth of any surface- 
current that might be driven into the bay. If deep enough to 
reach the shells, the wind-current would unite with the breakers in 
driving’ the shells up the slope shorewards. If not deep enough to 
reach them, the surface-current shorewards would generate an 
under-current seawards, which would oppose the shoreward impulse 
of the breakers. When such conflicting forces are at work it is not 
surprising that shells should be cast on shore by one gale and not by 
another, or that they should be abundant on certain beaches, whilst 
almost, if not quite, absent on others in the same neighbourhood. 

It seems unnecessary to adduce further evidence in proof that 
a wind blowing into a bay may set up currents both in its own 
direction and in a direction opposed to its own. The fact is one 
of common acceptation, as evidenced by the statements of Messrs. 
Dana and Geikie in their respective manuals, as already quoted, 
viz. “ The forcing of water into bays... . causes a strong current 
outward,” and “ A prevalent wind, by creating a current, .... will 
cause the shingle to travel coastwise.” But in this admitted 
action of the wind in causing currents we have, as it appears to me, 
an explanation of the apparent paradox, that winds and waves oc- 
easionally appear to drive large pebbles further than small, and at 
other times small pebbles further than large. 

In the passage already quoted (P. 31), Admiral Spratt bears 
witness to the fact that he has seen small clinkers travel along a 
coast faster than large ones ; but all sizes travelled in the same direc- 
tion. Mr. W. Topley, describing the beaches between groynes 
on the coast of Sussex and Kent, stated that “in each separate 
- area it was found that the largest pebbles had been carried... to 
leeward, and to the summit of the beach” (P. 25). These cases 


282 Scientific Proceedings, Royal Dublin Society. 


can be easily paralleled. They represent respectively that action 
of wave and current that strips a beach of all its contents, and that 
distributive action which may part the large shingle from the small, 
and the sand from both. Mr. Godwen Austen, describing the 
manner in which the materials of long lines of beach may be 
entirely swept away, stated that he had “seen, at one time or 
another, nearly every portion of our south coast in the condition of 
bare rock without sand or shingle..... *—(Q. J. G. 8., vol. vi., 
p-72.) [have myself described an extraordinary instance of stripping 
in the case of the sands at Blackpool, near Dartmouth, in April, 
1881, when the eastern half of the beach was laid bare.—( Trans. 
Dev. Assoc., vol. xiii., p. 345.) Extreme cases of stripping, such as 
that at Blackpool, cannot be attributed to mere wave action during 
severe gales. Gales from all quarters are common enough on the 
south-west coast ; but, though acquainted with Blackpool beach for 
more than five-and-twenty years, I have never heard of the eastern 
end being stripped except on the occasion referred to. 

One of the keys to the problem of the distribution of beach- 
material will probably be found in the fact that, whereas shingle 
on a beach must go with the wave, sand must go with the strongest 
current. If wave and current unite, the beach will be stripped ; if 
they act in opposition, the beach-material will be distributed. 

A good instance of shingle and sand travelling in contrary 
directions will be found on the north-western shores of Lyme Bay, 
between Hope’s Nose and Teignmouth. There is good evidence 
that between these points shingle travels from S. W. to N. E., that 
is, from Hope’s Nose towards Teignmouth, and that sand travels 
from N: E. to 8. W., the contrary direction. 

On the 23rd October, 1880, there having been a heavy easterly 
gale on the preceding day, I visited Babbicombe, and was there in- 
formed by the coastguardsman on the Down that the beach had 
been washed away from the Babbicombe side of the bay to the Oddi- 
combe side, 2. ¢. from S. W. to N.E. 

Before the gale referred to, a little cove, behind the Cary Arms 
Inn at Babbicombe, contained sufficient shingle to accommodate a 
bathing-machine, as is shown in a photograph taken by Messrs. 
Frith & Co. in 1878, and described ag the “ Bathing Beach, 
Babbicombe.” A photograph taken by myself in January, 1884, 
depicts it as a gully between the rocks, strewn with huge stones, 


Hunt—On the Action of Waves on Sea-beaches, &c. 283 


devoid of all shingle, and as unlike a bathing-cove as any place can 
be. The shingle in this cove was derived from quarries on the 
south-west, which were largely worked some years ago. We have 
in this case an instance of a beach on the north-western shores of 
- Lyme Bay, between Hope’s Nose and Teignmouth, being suddenly 
destroyed by the shingle travelling en masse to the northward. On 
Oddicombe beach the largest shingle collects at the north-eastern 
end. ‘There is little doubt that the bulk of the Oddicombe shingle 
came from the quarries to the south-west, already referred to; but 
the most incontestable evidence of the travel of large fragments of 
‘stone from 8. W. to N. EH. will be found in the “junctions” of 
greenstone and slate, traversed by calcite veins, which junctions are 
~ occasionally picked up on the beach up to its extreme north-eastern 
end, and are all derived from the coast between the S. W. end of 
Oddicombe beach and Babbicombe beach, where the greenstone rock 
bursts through the Devonian slate, forming a junction with it. 
Evidence of the south-western travel of the sand will be found in 
the direction of the sand-spit at the mouth of the river Teign, which 
stretches from the eastern towards the western bank of that river ; 
also from the persistent tendency of the sand derived from the 
crushed shingle to collect at the south-western end of the said Oddi- 
combe beach, one of the longest and most important beaches between 
Teignmouth and Hope’s Nose. ‘The point to which I desire to call 
attention is that, between Teignmouth and Hope’s Nose, sand 
has been observed to travel in a south-westerly direction, and 
shingle in a north-westerly direction, and that two observers, 
judging the one from the sand, the other from the shingle, 
would arrive at conclusions diametrically opposite as to the general 
driftage of beach-material on the north-western shores of Lyme 
Bay. Such a difference of opinion, as we have seen, has actually 
arisen in the case of the Chesil Bank, on the eastern shores of the 
same bay; those observers who have based their conclusions on 
the existence of sand to the westward of the shingle, and on the 
gradual diminution in size of the shingle from east to west, having 
contended that the driftage must be towards the sand from the 
shingle; whereas those who have more especially observed the 
action of waves on large beach-stones have contended that the 
shingle must have travelled from the direction of the sands. The 
difficulty will vanish when it is seen that both scts of observers may 


284 Scientific Proceedings, Royal Dublin Society. 


be right, and that under certain circumstances sand and shingle 

may be travelling across the same line in contrary directions. 

‘It may be observed here that, in the shingle-bank thrown up at 

Oddicombe by a severe gale from the southward and eastward, on 

September Ist, 1883, the shingle gradually decreased in size from 
N.N.E. to 8.S.W. In this case there was no doubt whatever 

that the shingle was larger to leeward than to windward. 

Lyme Bay, with its numerous minor indentations, between 
Portland and the Start, has presented many knotty problems for 
solution concerning the travel of beach-material. Of these there 
may be specially noted the reversed directions of the Teignmouth 
and Exmouth sand-spits, though but a few miles apart, the assort- 
ment of shingle in gradually decreasing or increasing sizes, as the 
case may be, and the exceptional height of the Chesil Bank above 
mean-tide level. It seems likely that the problem presented by 
any beach in Lyme Bay or elsewhere will yield to investigation if 
it be treated on its own merits, without regard to the possibly, to all 
appearances, contradictory phenomena presented by neighbouring 
beaches, in which the beach-material, and the conditions of wave 
and current action are not precisely the same. It is not, perhaps, 
too much to say, that on no two contiguous beaches, nor at the two 
ends of any one beach, are these conditions identical, though the 
difference may be but slight. In Lyme Bay the difference in the 
conditions of wave and current action on the eastern and western 
beaches is very great. From near Sidmouth to Portland its shores 
are more or less exposed to waves and currents generated in the 
Atlantic, whereas no point, even in Start Bay, though upwards of 
forty miles further down Channel, is similarly situated. Thus, 
whilst the western beaches encounter their heaviest seas from the 
eastward, the eastern beaches encounter their heaviest from the 
westward, and there is no comparison between the power of the 
waves in the two cases. Hven so, the difference in vertical height 
between the eastern and western beaches may seem unaccountably 
great, though much of the difficulty vanishes when we remember 
that the western waves act in concert with ocean-generated surface- 
currents and an abnormally high water-level in the Channel, 
whereas the eastern waves are only supplemented by a Channel 
current, and have their action diminished by an abnormally de- 
pressed water-level. 


Hunt—On the Action of Waves on Sea-beaches, &c. 285 


It may be observed, that the strength of the tidal currents at 
Portland can throw no light on the exceptional height of the Chesil 
Bank above the ordinary spring-tide level, however much the tidal 
currents, owing to the peculiar conformation of the coast, may 
augment the height of such ordinary level. 

The question of the motion of shingle and other objects along 
the sea-bottom at a distance from the shore presents as great 
difficulties to the student as its motion on and along sea-beaches, 
owing to authorities being at so great variance both as to the 
amount and cause of such motion. On the one hand, we have Mr. 
J. M. Rendell expressing his opinion that shingle can scarcely be 
moved by the heaviest waves at greater depths than three fathoms, 
and on the other, Mr. J.T. Harrison speaking of ‘‘ stones detached 
from the rocks” being “carried along the coast in deep water, 
knocked about here and there, and having their edges rubbed off in 
all directions”’ (P. 38). We find Mr. F'. Wynne going still further, 
and maintaining that ‘“‘the occurrence of any sort of rock as a 
pebble” on the Chesil Beach proves “the existence of a more or 
less exposed reef of that rock between the commencement of the 
shallow water of the Channel and this beach”’; and further, that 
“if syenite was found, then syenite existed in the bed of the Chan- 
nel, perhaps as far as the entrance of the Bay of Biscay” (P. 47). 
Between these two extremes all shades of opinion are held as to 
the power of waves, tides, and currents to propel shingle along the 
Channel floor. 

With respect to the existence of motion at considerable depths, 
the facts recorded by Messrs. Douglass, Stevenson, and Winder 
seem conclusive :—e.g. the lobster-pots filled with sand and shingle 
during heavy swells in thirty-fathom water: the coarse sand 
thrown on to the lantern-gallery of the Bishop Lighthouse (P. 46) : 
the relation of the depth of water in which mud is found to be 
deposited to the size of the waves that affect the locality (Steven- 
son on Harbours, 2nd ed., p. 21): the passage of a piece of iron 
plant round Dover breakwater in ten fathoms, whose track was 
traced by Mr. Winder, when himself on the sea-bottom.—(Kinahan 
on Sea-beaches, Proc. Roy. Irish Acad., 1879, p. 208.) In addition 
to these may be cited the jar nearly full of sand and gravel trawled 
off the Start (Trans. Dev. Assoc., vol. xii., p. 73, and Proc. Royal 
Society, vol. xxxiv., p. 10.); and the soda-water bottle trawled 
in about forty fathoms off the same headland, whose condition, as 


286 Scientific Proceedings, Royal Dublin Society. 


evidencing alternate periods of repose and disturbance, I have fully 
discussed elsewhere.—(TZians. Dev. Assoc., vol. xv., pp. 309-3865.) 

While the above facts testify to the existence of occasional 
motion on the bed of the English Channel, the following facts 
negative the possibility of such motion being due to any violent 
currents of translation that affect the surface of the bottom :— 

(1). The occurrence of angular shingle at various points westward 
of Scilly —(Map of English Channel, R. A. C. Austen, Q. J. G.S., 
vol. vi.) 

(2). The perfectly unworn state of chalk flints trawled fifteen or 
twenty miles off the Start and Eddystone. It may be observed, 
that two specimens, weighing respectively 3lbs. 2 0z. and 2 ibs. 
14 oz., taken twenty miles south-west of the Start, were unrolled. 
A small flint, 8 oz. in weight, taken fifteen miles south-west of the 
Eddystone, was very slightly abraded, though one weighing 6 lbs., 
taken five miles further to the south-west, was perfectly unrolled.— 
(Trans. Dev. Assoc., vol. xii., p. 293, and “ Corrigenda,” vol. xv., 
p- 365.) 

(3). The occupation of the Channel-bed by an extensive fauna, 
which could not exist in the face of currents sufficiently strong to 
sweep along sand and shingle. 

The advocates of powerful waves of translation, whether tidal or 
otherwise, have never disposed of the objection that the Shambles 
Shoal off Portland, composed as it is of light comminuted shells, 
could not possibly exist in the face of any such waves of translation. 
Waves that could sweep shingle up Channel to Portland would 
naturally sweep away every vestige of a shoal composed of such 
light material, at any rate for a time. But it is well known that 
the shoal in question is to all intents and purposes permanent. Sir 
John Coode has described it as ‘“‘an immense bank of fine broken 
shells, lying south-east of Portland, which was now in the same 
condition as when surveyed by Mackenzie, about one hundred years 
since, and having now, as then, a depth of only 11 feet of water 
over the crest’’ (P. 50). 

The persistence of the Shambles has been a perplexity to scien- 
tists from Sir H. de la Beche’s time up to the present, and, so far as 
I am aware, the advocates of the wave of translation theory have 
never attempted to account for the phenomenon. 

The persistence of shoals and sandbanks in the face of waves, 
however heavy, presents no difficulty so long as the waves are 


Hunt 


On the Action of Waves on Sea-beaches, &c. 287 


the ordinary sea waves of oscillation. A simple experiment 
in the artificial formation of ripple-mark illustrates incident- 
ally the action of waves on a shoal. ‘The experiment, as I have 
often made it, consists in placing an inverted flower pan in an 
experimental tank, and causing artificial waves of regular period to 
roll over it, and act on sand strewn upon its surface, or on a pane 
of glass resting on it. At first sight the waves seem to have no 
power to wash the sand off the pan, so little is the translatory 
motion in any direction. Occasionally such a motion can be de- 
tected. On one occasion, when experimenting with sand strewn on 
a gelatine film® (a convenient method for preserving the ripple- 
marks when made), I observed the sand-ripples evinced a tendency 
to travel forwards. On investigation, | found that the resultant 
forward current over the bank arose from the balance between the 
primary and secondary wave-currents being disturbed by the 
greater depth of water at the sides of the bank. JI have since 
found that an inward current over a raised surface can be trans- 
formed into an outward current by raising the sand at the sides of 
the bank, and thus converting the quondam bank into a depression. 

In the case of waves of oscillation we have seen that the water 
below the level of repose travels to meet the advancing wave-crests, 
and with the waves when above that level. ‘Thus, in the case of 
a sandbank just level with the surface of the water the whole of the 
wave-action affecting it must be forwards, as during the backward 
flow the surface of the bank, ex hypothesi, willbe high and dry. In 
such a case, however, the forward current cannot be fairly described 
as a wave of translation ; itis but one half of a wave of oscillation, 
whose other half has been applied elsewhere. The result of such 
unbalanced action will be the depression of all the bank to a limi- 
ted depth below the surface of the water, unless the sand be accumu- 
lated by currents faster than the waves can dislodge it. Marine 
shoals and sandbanks are commonly the joint production of wave- 
currents and tidal-currents. The neutral wave-currents keep the 
component parts in motion, whilst cross-tidal-currents accumulate 
them. Occasionally an important sandbank results from these 
combined effects; more commonly the result is a collection of 
dead shells, or shell-sand, known only to the trawler-man or dredger. 


5 An ordinary photographie dry plate. 


288 


1872. 
1872. 
1871. 


1878. 


1873. 


1873. 
1873. 


1874. 


1874. 


1878. 


1880. 


Scientific Proceedings, Royal Dublin Society. 


November 22, . 
November 28, . 


December 12, . 


February 1, 


February 4, 


February 14, . 


May 12, . 


January 13, 


January 26, 
» 29, 

March 4, 

May 12, . 


April 18, 


» 27, 


October 15, 


APPENDIX. 


NOTES. 
Three valves, Thracia convexa, under Daddy Hole. 
Various shells, including live Lucinopsis wndata. 


Live Oyprina Islandica, one Thracia convexa, and other 
shells. 


Heavy easterly gale. 


Paignton Sands strewn with Cardiwm tuberculatwm and C. 
aculeatum, curiously assorted.—(Zrans. Dev. Assoc., 
vol. vili., p. 183. 


Had a haul under Daddy Hole, and caught nothing but weed. 


Caught dabs (by hook) feeding on red arms of spinous cockles. 
A. few weeks previously, had myself dredged a great 
many cockles dead and dying, and totally denuded of 
spines. 


Dredged about 100 cockles off Paignton. All rolled, except- 
ing new growth sufficient to carry two, and in some cases 
three spines on each rib. In many cases the shells had 
been again rolled, and the process of repair recom- 
menced. 


Took 18 species of shells under Daddy Hole. 
Took 31 ”? ” 2 
Fine valve of Thracia convexa on Paignton Sands. 


Took a good specimen of Zhracia convexa (dead) in ‘‘ The 
eit? 


Five hauls on cockle-ground off Paignton. Did not take a 
valve of cockle of any sort. 


Told that the cockles were ashore at Paignton. Found the 
sand strewn with them. 


Dredged off Daddy Hole. Dredge almost empty. Plenty of 
dead shellsin ‘‘ The Pit.’? Torbay seems bare of shells. 
After a week’s easterly breezes, with rough sea, there are 
scarcely any fresh cockles on Paignton Sands. 


Hunt—On the Action of Waves on Sea-beaches, &c. 289° 


1881. October 19, . LEasterly gale. 


xr », 931, . Went out to ascertain effects of recent gales on bottom of bay. 
Between Torquay and Paignton some very small cockles, 
with spines perfect, and showing no signs of damage. 


’ I have elsewhere recorded how severely these gales had dealt with some of the 
larger shells and ascidians in the bay (Proc. R. S., vol. xxxiv., p. 4); and the oc- 
eurrence of these delicate little cockles in shallow water, at one of the most exposed 
points in Torbay, was at the time an inexplicable enigma. 


1881. December 25,. My boatman brought me some adult C. aculeatuwm, taken in 
herring-nets off the Gas-works (Hollowcombe). During 
the past year I have taken none in the dredge. 


1882. October 8, . . On the ‘‘ Gas-house Sands’’ (Hollowcombe) picked up an 
old iron gas-pipe covered with solid tar-stuff. Had it in 
my hand some time, and took particular notice of it. On 
rowing off to my sailing-boat, we ran off to a spot be- 
tween Paignton and Torquay, where small cockles were 
abundant last year. Found none. Then on to Daddy Hole. 
On the way I pointed out to my boatman that the reason 
shells {collected there, and at Fishcombe (on the south 
side of the bay), must be owimg to an under-current 
during easterly winds. Off Daddy Hole found the 
usual shells collected. The second haul of the dredge 
brought up a rolled piece of tar-stuff about the size of 
my fist. Next haul brought up a piece of peat from 
Torre Abbey, and a handful of small coke the size of 
walnuts. The Gas-house Sands haye been covered with 
coke all the summer. 


1882. October12,. . Dredged under Daddy Hole. An immense number of dead 
shells, one old patella, some clinker and cinders, ap- 
parently from steamers. 


1882. October13,. . Meadfoot. Searched high-water mark carefully, from slipway 
to rocks at west end, and did not find a single shell, 
except one unrecognizable fragment, as smooth as china. 


1882. November 13,. Fresh N.E. gale. Whilst observing the beach at Meadfoot, 
a barque ran into the bay. Went round to harbour to 
watch her. George Cumming, a boatman, discussing 
her position, remarked that in easterly winds there was a 
continuous flood-tide (i.e. east-going current) along the 
shore. Sometimes a “‘regular current’’ past the pier 
head. Same morning, I watched through a telescope a 
number of black duck swimming just on the edge of the 
breakers off Paignton. Sometimes the seas would break 
outside them, when they would dive, and come up again 
in about the same place. (See Yarrell, Brit. Birds, 
vol. iii., pp. 825, 327.) 

SCIEN. PROC. R.D.S.—VOL. IV., PT. VI. 2D 


290 Scientific Proccedings, Royal Dublin Society. 


1882. November 17,. Tried ground under Daddy Hole. Dredge brought up half 
a bucketful of stones. It would appear that the late 
N.E. gale must haye caused an inset on the north side 
of Torbay. My boatman volunteered the remark, that 
on the day the barque that took shelter off Torquay Pier 
sailed away, the seine boats shot their seines off ‘‘ London 
Bridge,’”” expecting an east-going current as usual in 
easterly winds; but that their seines were so rapidly swept 
to the westward, that they had tohaul them in at once, “end 
on.’ Tried two hauls across the line, in which I took the 
stones, but could not hit them off again. ‘They must have 
been very local. On subsequently examining the stones 
dredged on the 17th, I foundamongstthem upwardsot 1000 
shells and fragments. These shells, in their general aspect, 
differed materially from those usually found off Daddy 
Hole. They differed both as to species, character, and con- 
dition. Among them were nine specimens of Cyprea euro- 
pea, nine specimens, or fragments representing individuals, 
of Patella vulgata, Helcion pellucidum, Fissurella greea, 
Littorina obtusata, and a fragment of an adult Cardium 
norvegicwm. Fragments of a balanus were abundant. 
Many of the shell-fragments consisted of small pieces of 
thick shells, such as can commonly be met with to the 
eastward of Daddy Hole, especially off the raised beach, 
where, at one spot, the bottom consists of broken shells ; 
but such as are not usual on the sandy bottom of Daddy 
Hole, or to the westward thereof. The stones were 
similar in appearance to the shingle of Meadfoot beach, 
and it might occur to some that the shells had come off 
that beach. But I have already pointed out that a special 
search on October 13th, a mouth previous to the gale 
referred to, resulted in but one worn fragment being 
found there; and I may add that a second search, on March 
21st, 1883, from the slipway to the western rocks was 
not repaid by a single fragment of any sort. The portion 
of the beach examined on both occasions was that part, 
west of the slipway, where the waves can expend them- 
selves on a natural beach, uninfluenced by the sea-wall. 


fon J 


XXXII.—NOTES ON THE MICROSCOPICAL CHARACTER OF 
THE VOLCANIC ASH FROM KRAKATOA. By J. 
JOLY, B.E., Assistant to the Professor of Engineering, 
Trinity College, Dublin. Prarzs XII. and XIII. 


[Read, March 17, 1884.] 


On the 26th of August, 1883, the Norwegian barque Borjild 
(Captain Amundsen), on her way from Cherribon to Anjers, cast 
anchor off the east coast of the Great Kombuis Island, some 
seventy-five miles to the north-east of Krakatoa. Here she re- 
mained during the period of the eruption; volcanic ash falling on 
her decks from 6 a.m. to 6 p.m on the 27th. On that day, at 
2 p.M., the darkness, due to absorption by the great layer of dust 
above them, was described as being so intense that mutual recogni- 
tion by vision was impossible. 

In the month of February, during the stay of the Borjild 
at Dublin, a portion of this ash was, through the kindness of 
Mr. Hogg, of Trinity College, obtained by the author. The 
examination of this ash forms the subject of the following notes. 

Mere inspection with alens shows the ash to consist principally 
of vesicular fragments of pumice interspersed with vitreous and 
erystalline particles. Before dealing with these it is interesting 
to note the presence, as of accidental origin, of 

Sodium Chloride.—The presence of this substance may readily 
be demonstrated by taste; or by immersing in distilled water and 
testing. Mr. Moss, who first called attention to it, estimated it to 
be present to the extent of 0°8 per cent. 

Organic Marine Remains.—Those noticed were foraminifera, 
of which some quite perfect shells were found, and also frag= 
ments of starfish (identified by Professor Sollas). Similar remains 
were removed from the external cells of a specimen of the “ floating 
pumice,” picked up by the Boryi/d in the Straits of Sunda. 

Perfect identity, mineralogically, seems to exist between this 
floating pumice and the ash. Larger crystals may, however, be 


obtained from the former than occurred in the latter. Feldspars 
2 1D) @ 


292 Scientific Proceedings, Royal Dublin Society. 


3 mms. long were found protruding from the abraided surface of 
the block pumice. In the dust they rarely exceed 1 mm. in 
length. The formation of the dust by mere pulverization of the 
pumice seems a most likely supposition. 

With regard to the modus operandi of preparing this dust for 
the microscope, it may be useful to note that while it was found 
that mere shaking up with water, and pouring off before complete 
settlement, served to remove the lighter fragments of pumice, 
complete separation was only readily effected by the following 
method :— 

Into a glass tube 1 m. long and about 4 cms. in diameter, 
closed at one end and filled with water to the brim, the partially 
cleansed dust is introduced and allowed to settle. A slip of glass is 
now pressed on the open end, and the whole rapidly inverted into 
a shallow dish containing water. The denser particles descending 
most rapidly through the column of water in the tube reach the 
dish first. When the more slowly moving particles are observed 
to have nearly attaimed the dish, a movement of the tube to one 
side effects the desired separation. 

One and all the constituents of this ash present under the 
microscope a spectacle of the most extreme interest and beauty. 
The almost unlimited minuteness of the vesicular structure of the 
pumice, the endless variety in form and colour of the amorphous 
fragments, the exquisite perfection of form exhibited by the minute 
crystals of magnetite, of pyrites, of pyroxene and of feldspar; the 
nebules of enclosures in these last, and their delicate overspreading 
lace-work of still adhering vesicular glass. Here are seen small 
crystals enclosing many others, and these again, still others; while 
often with the symmetry of the crystal the vitreous inclusions, 
amber-yellow, range in concentric zones in the translucent depths. 

But if this be a wonderful spectacle viewed by ordinary trans- 
mitted light, the beauty and wonder of it are a thousandfold 
increased when, rotated in polarized light, each feldspar crystal 
reveals its molecular symmetry in flashes of changing colour beside 

vhich the richness of the emerald, ruby, or saphire, would pale. 
the abundance of twinned crystals add much to the effect: and 
now, also, many fragments passed over before as less interesting 
put in their claim to symmetry, and shine not less brightly than 
those displaying facet and angle. Many hundreds of square miles 


Jouy—WNotes on Volcanic Ash from Krakatoa. 293 


were thickly covered with this ash around the scene of the erup- — 
tion, and these miracles of structural perfection doubtless abundant 
in every grain of it. 

Dealing with the constituent minerals in the order of their 
abundance, the Fe/dspars first claim attention. They will be at 
once identified by their colourless transparency; specimens ex- 
hibiting a milky decomposed appearance, or showing diffused iron 
stains of brown-yellow tint being rare. In the latter case, also, a 
few moments’ immersion in hydrofluoric acid generally shows the 
colour to be confined to the covering of pumice glass adhering to 
the surface of the crystal. 

This covering of pumice, most noticeable in the feldspars, but 
also overspreading pyroxene crystals, is obviously the remains of a 
former matrix of highly vesicular glass; being occasionally even 
recognisable as the fragments of bubble walls; sometimes project- 
ing along the edges of the crystal, giving a fringed appearance, or, 
again, overspreading the more developed faces forming a hexagonal 
pattern often of great beauty and regularity. The appearance, 
indeed, suggests at first sight such markings, cohesion figures, as 
are formed when two flat surfaces compressing a viscous material 
are suddenly separated. It will be found, however, that crystals 
removed from the block pumice carry with them just such remain 
of the matrix. 

Optical examination could not safely be undertaken till this 
coating had been removed by hydrofluoric acid. This operation 
demands care, as the feldspars themselves are soon decomposed by 
the acid. 

Two principal forms of feldspar crystals occur ; a columnar and 
a tabular, the latter most abundantly. 

That the tabular variety 1s in general plagioclastic is certain. 
Polysynthetic lines of twinning are frequently observed with 
polarized light, sometimes crossing at right angles. More gene- 
rally these lines traverse the crystal longitudinally. Carlsbad 
twinning is common, extinction occuring at some 8 or 9 degrees at 
either side of the medial line. This form of twinning is seldom 
absent in crystals of the columnar variety. If such tabular crys- 
tals as exhibit this medial twinning line be considered as of the 
same nature as the columnar crystals, a plagioclastic character 
might be ascribed to the latter, as just such tabular crystals will be 


294 Scienlijic Proceedings, Royal Dublin Society. 


met superimposed and twinned with others exhibiting undeniable 
plagioclastic characteristics. At the same time, many orthoclastic 
peculiarities are, as will be seen presently, noticeable in the colum- 
nar crystals. ; 

Little or no cleavage is apparent in these tabular crystals. 
Extinction does not occur parallel to the edges of the dominant 
faces—apparently macropinacoids. Want of properly furnished 
instruments forbids the author entering at present further into 
the anomalies presented by these plagioclastic feldspars. They 
are quite insoluble in boiling hydrochloric acid—or after some days’ 
cold digestion in the same. 

The second variety, if it may be considered as such, may be 
described as columnar, with nearly equally developed faces seem- 
ingly at right angles to each other. Four pyramidal faces termi- 
nate one or both ends. This pyramidal termination is occasionally 
truncated, giving a fifth terminating face at an angle other than 
90° with the zone axis of the prismatic faces. Marked rectangular 
cleavage on one set of these faces; direction of cleavage apparently 
parallel to pyramidal planes: generally a single medial twinning 
line on the other set of prism faces. Extinction for the first set of 
faces (those showing cleavage), parallel to the longitudinal axis of 
the erystal. For the second set, symmetrically on either side of 
twinning line; seldom more than 15° on either side. A specimen 
wanting the twinning line extinguished on these faces at 16° with 
the longitudinal axis; parallel to it on the adjoining faces of the 
same zone. 

Viewed when resting on one of its longitudinal edges, charac- 
teristic border lines displaying vivid prismatic colours become 
apparent between crossed nicols. Polysynthetic surface striations 
might account for this appearance. 

The photograph (Pl. xi. fig. 1), taken with nicols crossed, con- 
tains a couple of these crystals removed from the floating pumice. 
The crystals, adhering together, rest on their edges and display 
well the border lines just mentioned. (Figure 1a. Pl. xii.) 

Flame tests indicate for such crystals a percentage of potassium 
comparable to that of orthoclase. If they, indeed, are sanadine, 
there is evidently a peculiarity in twinning. Although good crys- 
tals are scarce, iragments are numerous. They will be detected 
by their marked cleavage. 


Joty—Notes on Volcanic Ash from Krakatoa. ae 


The tabular variety is represented in the photographs by the 
remaining crystals shown in the photograph (PI. xii. fig. 1), which 
is taken at an enlargement of about 20 diameters. A very good 
specimen is shown, magnified 35 diameters, in Plate xu. figure 2: 
enclosures, vitreous, containing crystals, will be noticed. Growth 
striations and the lace-like pattern of adhering-glass are also 
shown. ‘The presence of growth striations or zones, very common 
in these feldspars is generally assumed to indicate a more or 
less tranquil formation. 

The Pyroxvenes are a noticeable feature in this ash. The 
rhombic variety is by far the most abundant, indeed the mono- 
clinic is scarce, and present usually in badly developed or small 
crystals. A group of the rhombic pyroxenes is shown in Plate 
xii. figure 4. Hnlargement 15 diameters. 

These crystals are olive-green to brown in colour; translucent. 
Their pleochroism is well marked, the colouration following the 
order assigned to Hypersthene, by MM. Fouqué and Levy (Minéra- 
logie Micrographique): that is, parallel to their principal axis 
dark-green, parallel to the macrodiagonal, red, with intermediate 
tints of brown. | 

This mineral will be found to extinguish parallel to its pina- 
coidal faces, not alone when viewed longitudinally, 
but also when placed with its principal axis in a 
vertical position between crossed nicols. Treating 
in this way the nearly central crystal, the one ex- 
hibiting a pointed termination at each end in the 
group (Pl. xii. fig. 4), the exquisite perfection of 
its minute form became apparent. 

This crystal, which parallel to its longitudinal 
axis shows pinacoidal and prismatic faces, the 
former dominant, shows four principal termi- 
nating planes, apparently octahedral. ‘T'wo other 
faces, brachydomes seemingly, are well defined. 
Other minute faces are visible, scarcely determin- 
able. The adjoining woodcut, a sketch of its 
appearance viewed in a direction inclined a little 
upwards, and to the left of the brachydiagonal, shows some of its 
faces. 


The photograph (PI. xiii. fig. 3) conveys but a faint idea of a very 


Ee) Scientific Proceedings, Royal Dublin Society. 


beautiful specimen—consisting of three interpenetrating crystals. 
Their faces are very perfect, and extinction for each crystal is 
parallel to its longitudinal axis. These are soluble in hydro- 
fluoric acid after long immersion. Just such crystals are depicted 
in the Minéralogie Micrographique of MM. Fouqué and Levy, as 
extracted from the lavas of Santorin of 1866. 

The monoclinic pyroxene, Augite, which so closely resembles the 
hypersthene in appearance will be found to be only feebly or not 
at all polychroic. Hxtinction occurs at some 30 to 37 degrees with 
the principal axis. ‘This angle is stated to vary with the amount 
of iron present in the mineral. It is never so low as to confuse it 
with hornblende. 

In general its crystals are of a brighter green colour than the 
greenest of the hypersthene. They, also, are slowly soluble in hydro- 
fluoric acid. Crystals of hypersthene 4 mms. long were picked 
up: the augite rarely was found above 1 mm. in length. Similar 
erystals fell in Norway in a volcanic ash from Iceland (Fouqué 
and Levy, op. cit.). 

Magnetite occurs not alone abundantly as inclusions in the 
various crystals, but is plentiful as minute octahedrons exhibiting 
the usual twin forms with octahedral composition face. It shows 
a fine black, splendant, metallic lustre; occasionally bluish and 
even like that of anthracite. An electro-magnet enclosed in a long 
test tube was found of much service in removing it from solutions, 
and also in isolating the pyroxene containing this mineral. 

Tron Pyrites is present in such characteristic forms as to leave 
little room for doubt as to its identity. It will be observed not 
alone in isolated fragments, little aggregations of cubes showing 
the striations at right angles on adjacent faces, and exhibiting the 
brassy lustre of pyrites, but also, imbedded in and protruding from 
the surface of some of the rough amorphous fragments scattered 
through the ash. In good light the faces of these crystals are seen 
to be generally pentagonal, and the crystals in fact to be principally 
pentagonal dodecahedrons. 

It was thought that this substance might be foreign to the real 
constitution of the ash. ‘The discovery, however, of a crystal with 
the lustre and appearance of pyrites imbedded deeply in the in- 
terior of a feldspar rendered it impossible to suppose this mineral 
to be merely blown up from local rocks, and so intermingled with 


Joty—WNotes on Volcanic Ash from Krakatoa. 297 


the ash. Remarkable deposits of it, having the appearance of in- 
filtration along cleavage planes, occur occasionally in feldspar 
crystals. 

Among the amorphous fragments, Olivine was not observed ; 
many fragments picked up on suspicion being found to be easily 
soluble in hydrofluoric acid. 

One of the most interesting features of this ash is the nature of 
the various enclosures in its principal minerals. They obviously 
give us a means of judging of their relative order of formation. 

Classifying on this basis, Magnetite would come first in order 
of formation. It occurs as an inclusion in all the silicates present. 
it will be noticed protruding from the crystals of hypersthene in 
figures 3 and 4. 

Pyrites might be of contemporary origin. 

The Pyroxvenes would in that case be second in order, for while 
including magnetite they are themselves included in the feldspars. 

The Feldspars were probably the last minerals formed. 

Vitreous inclusions. are abundant, generally iron stained to a 
light-brown. tint and enclosing the bubble which probably started 
their formation. Very often these inclusions are ranged parallel to 
the outline of the crystal; often again the vitreous mass has had 
the symmetrical form of the containing crystal impressed upon it. 
Sometimes then by their individual form, sometimes by their dis- 
position, it is possible to judge of the former crystalline symmetry 
of a mere formless fragment containing such enclosures. 


ADDITIONAL NOTES. 


Subsequent to the reading of the foregoing, the author received 
many additional samples, both of the ash and of the block pumice. 
To the courtesy and kindness of Mr. T. Brewis the author owes these 
specimens in the first instance. Through information received from 
that gentleman samples were obtained from Captains who were in 
the neighbourhood of Krakatoa during the period of the eruption. 
To Captain Ralston, of the Niobe; Captain Calangich, of the Jafet IT. ; 
and, above all, to Captain Thomson, of the ship Medea, the author’s 
best thanks are due. 


298 Scientific Proceedings, Royal Dublin Society. 


The specimens of block pumice received bore, one and all, remains 
of marine life, incrusting the walls of the larger surface cells. Muine- 
ralogically they were not found to differ; many, however, showed veins 
or layers of black vesicular glass, giving a stratified appearance. The 
specimens, some of which are now in the Museum of Science and Art, 
Dublin, were picked up considerably to the south-west of the Straits of 
Sunda. 

Dust from Batavia did not, on examination and comparison with 
that gathered at half that distance from Krakatoa, indicate any such 
sifting of its constituents in the course of its journey as M. Renard 
assumes in his Paper, read before the Académie Royale de Belgique 
(November 8, 1883). The probable explanation is that the dust was 
thrown so high, and in such quantities, that for many miles it was 
descending almost vertically, and was not, therefore, subjected to such 
a sifting process as it would have experienced had it been travelling 
horizontally. 

Bearing on this point, the following computation respecting the 
height to which the dust, &c., was projected may be of interest res 

Captain W. Thomson heard the first explosion of Krakatoa at two 
o’clock on August the 26th. He was then in Lat. 5° 56’S., Long, 
106° 31’ HK. Immediately after, and before the second explosion. 
which succeeded in ten minutes, a ‘“‘ black mass, rolling up, like 
smoke, in clouds was observed to the westward.’ It attained an 
altitude of about 12°; and, as the Medea will be found to have been 
just seventy-six miles, as the crow flies, from Krakatoa, a height of 
about seventeen miles is obtained for the cloud. 

At five o’clock the Medea came to an anchor in Lat. 5°58’ 8., Long. 
106° 46’ E., 89°38 miles direct from Krakatoa. The dust cloud had 
meanwhile been going up suddenly with each explosion; and now, as 
Captain Thomson cast anchor, he read the angle of elevation of the cloud, 
it was 40°. Obviously the column had advanced towards him; but some 
idea of its approach may be gathered from his subsequent statement 
that ‘the wind during the whole of the eruption was W.S.W., force 
between 3 and 4.” Taking its velocity as twenty-one miles per hour, 
its advance in the three hours since the first explosion would be sixty- 
three miles. On this assumption the altitude of the cloud would be 
twenty-one miles. Other observations from other points of view would 
be of interest. 

Captain Thomson’s narrative is one of much interest from the in- 
telligence and care displayed in his observations, although made under 
trying circumstances. 


Joty—Wotes on Volcanic Ash from Krakatoa. 299 


He records “ electrical displays”’ round the vast column of smoke 
(steam) ascending from Krakatoa on the evening of the 22nd of August. 
These took the form of vivid lightning, flashes darting from and around 
the column. Showers of sand and gravel on the 23rd. The terrific 
explosions of the 26th and 27th are described as “‘ shaking the ship.” 
He was then some eighty miles off, with an intervening screen of 
mountainous country. 

With regard to the presence of Pyrites in the ash, nothing was 
sald about it by M. Renard in his original Paper (which was not, how- 
ever, known to the author of these notes at the time of preparimeg his 
communication to the Royal Dublin Society); but in a note appended 
to a Paper appearing in Nature (April 17th), as the joint production of 
that distinguished mineralogist and of Mr. Murray, its occurrence is 
mentioned and dismissed as ‘‘ accidental.’’ It is, however, not alone 
present, free, as aggregations of cubes and dodecahedrons, but also as 
an inclusion in the feldspars and in the hypersthene. Again, its 
abundant occurrence in the ash received from various localities is 
observable. Fifty specimens were counted by the author in one of 
three slides prepared from about half a gramme of the dust from 
_ Batavia. The dust had been treated for the removal of glass, feld- 
spars, and free magnetite. It is hard to see why, under the circum- 
gtanees, it should be considered accidental. 

Hematite in thin, blood-red, semi-translucent flakes occurs in the 
ash. It is neither cleavable perceptibly, nor elastic, and is soluble in 
hydrochloric acid. It shows no trace of dichroism. 

The very great abundance in the ash of Hypersthene, compared to 
Augite, suggests that the original rock should be considered more of 
the nature of a hypersthene andesite than an augite andesite. In con- 
nexion with this point the results of Mr. Whitman Cross’ examination 
of a hypersthene andesite, kindly brought under the author’s notice 
by Professor V. Ball, are of much interest. (Bulletin of the United 
States’ Geological Survey, No. 1, 1883.) 


NOTE ADDED IN THE PRESS. 


M. C. Flammarion, in the Revue d’Astronomie Populaire, July, 
1884, p. 265, estimates the probable height of projection of the dust, 
&e., from Krakatoa as at least 20,000 metres (124 miles). 

Observations made on board the Zlizabeth, on the comparatively 
insignificant explosion of May the 20th, 18838, gave 11,000 metres as 
the height of projection on that occasion. 


8004 


XXXIII.—ON AN ARGENTIFEROUS GALENETIO-BLENDE AT 
OVOCA. Br C. R. C. TICHBORNE, LL.D., F.C.S., é&c. 


[Read, October 6, 1884.] 


I am strongly of opinion that we should never lose an oppor- 
tunity of bringing before the scientific public any natural product 
of this country which is likely to become of commercial value. The 
general uncertainty which appertains to all mining operations ap- 
pears aggravated in Ireland, where it almost seems as if we hung 
upon the fringe of extensive mineral deposits. ‘The want of smelting 
materials adds greatly to our difficulties. In the year 1875 I had 
the honour of placing before this Society! a specimen of a rich 
magnetite found in Wicklow, which at that time was unknown to 
the Geological Survey. The veins of this ore could be traced for 
some two milesor more. Consignments of the magnetite were sent 
to Staffordshire to be smelted, and the most flattering account of 
the quality of the iron obtained therefrom was returned; yet I 
believe this ore lies perdu. 

I wish, on the present occasion, to bring before the Society a de- 
scription of another ore of even more importance. Of this ore very 
little is known, and I intend to offer some speculations upon its 
general character. I believe that the lode may be typical of many 
ores, which will be found disseminated in lead mines, but of these 
there is no record except a short reference in the Mineral Statistics? 
for the year 1882, and also a reference to which my attention has 
been drawn within the last week, and subsequent to my analysis 
and report upon this mineral, viz. :—a paragraph in a Paper en- 
titled, “Notes on the Ancient and Recent Mining Operations in 
the East Ovoca District,” by P. H. Argall. 

The mineral I am now about to describe is known as “ Blue- 
stone,’ and locally in Wicklow as ‘“‘ Kilmacooite,” from the dis- 


1 Journal of the Royal Geological Society of Ireland, vol. iv., part 4. 

2 Mineral Statistics of the United Kingdom of Great Britain and Treland, for the 
year 1882, pp. 88 and 94. 

3 Scientific Proceedings, R. D. §8., vol. ii., nN. s., p. 225. 


TicHBORNE—On an Argentiferous Gatenetic-biende. 301 


trict called Kalmacoo. Itisso called in Mr. Argall’s Paper. The 
mineral seemed to have been well known to Mr. G. H. Kinahan, 
whose intimate knowledge of the mineralogy of county Wicklow 
induced me to make inquiries of him. He gives as localities—the 
lode of the Magpie mine and the Connary mine, both in Hast 
Ovoca, with the Mona mine in Anglesey. 

It is called ‘ Bluestone” by the mining inspectors,! and it seems 
that about 1,240 tons of this or a similar ore are raised in the prin- 
cipality during the year. 

The ore is a hard, steel-grey-coloured mineral, having something 
of the appearance of sulphide of antimony. Ii we except the colour, 
however, it does not resemble that mineral in any respect, for the 
structure is that of a fine-grained sacchorid mass. The ore is 
extremely hard, and it is broken with difficulty. In fact the rock 
has to be quarried by blasting. The pieces I have seen are very 
uniform in character, but are occasionally interspersed with crystals 
of pyrites and a hard, black, siliceous rock. A very slight exami- 
nation will suffice to determine the fact that this mineral is a natural 
lode, and is not the result of an ancient working. This latter theory 
was once upon a time promulgated. 

A piece weighed in the air 34:942 grammes: when weighed in 
water it gave 27°0605 grammes as the weight, so that the mineral 
has a specific gravity of 4°786. It will be observed that this gravity 
is somewhere intermediate between galena and blende. It is harder 
- than either of those minerals. ‘I'he ore, as found in Ovoca, seems, 
from the description given of the Welsh mineral, very much of the 
same character. But I have never seen a specimen from the Mona 
mine. As will be perceived further on, however it differs in 
general composition, it is much richer in silver than one of the 
varieties found in Wales. To quote from the Mineral Statistics, 
we are told that “ Bluestone is an ore of zinc; average analysis— 
zine, 32°15 per cent.; lead, 11°6, and 102 ounces of silver per ton, 
with a small percentage of iron and copper.” But at page 88 in 
the same book we are informed that from the Mona mine, in 
Wales, they extract 5°535 ozs. from 514 tons, and that at the 
Morfa Du mine 5:082 ozs. from 726 tons, which represents re- 


1 Mineral Statistics of the United Kingdom of Great Britain and Ireland, for the 
year 1882, p. od. 


302 Scientific Proceedings, Royal Dublin Society. 


spectively 103 and 6-9 ozs. per ton. The following is the analysis 
of the argentiferous galenetic blende, so-called “ Bluestone,” as 
found at the Connary mine, HK. Wicklow. 


Silver,! 3 : Z ; : ; ‘ 0-024 
Line se ; : ; : : 4 x 25°27 
iWeadsaae ; : : : : , 3 25°18 
iromki ; : } 3 : ‘ : 5°51 
Manganese, . ¢ ; A : trace, 
Antimony, . : . : : : : 0-21 
Arsenic, : ; : ' : : 5 0:08 
Copper, : : : : : : : 2°50 
Aluminum, . : ; ‘ 0°60 
Magnesium, with traces e Calum: 5 : 0:02 
Sulphur, 5 ; ‘ : : ; 23°71 
Silica, &c., . ; : : : : : 16°896 
100-000 
This mineral may therefore be said to consist of 
Sulphide of Zinc, 5 : : . 98768 per cent. 
Sulphide of Lead, : : ‘ . 29:07 is 
Sulphide of Silver, . : 5 #kOO: Qi ome 


and contains variable quantities of pyrites, which in this particular 
specimen amounts to 10 per cent. 

The sulphide would represent nearly 22 per cent. of the sulphur 
found. 

It was examined for the rarer metals by the spectroscope, but 

no indication of those elements could be got. 

Gold was present in very small quantities. It was not estimated. 

Mr. A. Ryder, of the Ovoca Mining Company, has kindly given 
me the following information upon the subject of the lie of the 
ore :—‘‘ The bluestone commences immediately to the east of a 
fault. It is here very rich in sulphur, and consequently of little 
value. We have driven on it for about 120 fathoms east, and have 
found that it mcereases in size (2. e. thickness of lode) and value as 
we go east. It also increases in value as we go deeper. It is the 
most ‘bunchy’ ore I know, growing in one place from 4 inches 
thick ND, to 3 feet 6 inches. In a distance of four fathoms I 


t Faecal to 8°6 ounces per ton (nearly 8 ounces troy). 


TicHBoRNE—On an Argentiferous Galenetic- blende. 303 


calculate that there are about 1,000 tons in sight. The bluestone 
seems to be surrounded by coal, with veins of bluestone on the 
north, and on the south side blue slate, and white micaceous schist, 
and deeper down comes iron pyrites.”’ 

Of course, from a commercial point of view, the amount of silver 
found in this ore is the most important item of the analysis. Our 
analysis gives rather different results from those obtained in the 
Welsh mines, but they do not agree at all with the analyses given 
in the notes to Mr. Argall’s Paper. Five analyses are given, and 
silver is only mentioned in three out of the five, which give respec- 
tively 5, 74, and 6 ounces per ton'. From reasons which we shall 
shortly stabes we think it probable that most of the samples must 
have been not only poor in silver but very indefinite samples of the 
bluestone. It may be interesting to compare this argentiferous 
ore with some others which are well known and worked for their 
silver. The following figures are taken from Dana’s Mineralogy, 
dth edition :— 


Argentiferous Galena, Hartz, ; . ‘03 to :05 per cent. 
English Galena, . ; : ; . ‘02 to :06 sf 
Lead Hills, . : ‘03 to :06 5 
American ores which are soneeal run as 

low as : : . 001 
Argentiferous ore fon Orada: ; . O24 


The last-named Ovoca ore compares very favourably with the 
above list, which includes some of our great sources of silver. If 
we examine this mineral with the naked eye, particles of pyrites 
may be seen scattered through the mass in an accidental and rather 
 erraticmanner. ‘The remainder of the mineral is, however, remark- 
ably homogeneous, and will bear examination under the microscope 
by reflected light with considerable impunity. The silver exists as 
sulphide, because dilute sulphuric acid does not dissolve any trace 
of that metal from the mineral. 

The actual composition of this ore brings us to the consideration 
of two points, viz.:—(1) How far we should be justified in con- 
sidering it as a distinct mineralogical specimen; (2) The construc- 


1 Since this Paper went to Press, samples of the ore have been assayed in London, 
giving as high as 9 ozs. of silver per ton, and also containing 1 dwt. of gold. 


304 Scientific Proceedings, Royal Dublin Society. 


tion of the names it has received. I may as well state at once that, 
as regards the last point, I havea strong objection to the naming of 
minerals after places, particularly when named after small and 
unknown localities. ‘Thus Dana has named a fine-grained mixture 
of galena and blende Huasolite, from the province of Huasco, where 
it was found. LHven here, 1 am of opinion that such terms are not 
desirable, if we wish to inculeate the idea that they are distinot 
species. A province, however, is generally well known, and it is 
quite different to Kilmacoo—a local name, not even to be found 
in any published gazetteer or postal directory. The objection 
would be obvious, because until we got “‘ Kilmacooite” recognized 
in the text-books upon mineralogy, the man of science would be at 
a loss to know what that name meant, or even to trace its con- 
nexions. There is also as great an objection to the term “ Blue- 
stone,” thename used by the miners in Wales. The mineral is of a 
steel-grey colour, not blue; and, besides, this term is applied to a 
well-known chemical substance. I therefore prefer to call it 
argentiferous galenetic blende. 

I view the mineral as an intimate mixture of fine crystals of 
galena and blende, which, although they form a fine-grained sac- 
chorid mass, apparently homogeneous to the eye, I have no hesita- 
tion in saying is composed of a mechanical mixture of microscopic 
crystals of two minerals. When treated. with dilute nitric acid, 
the blende seems to be attacked first, but I do not attach much 
importance to this fact. If, however, we powder some of the 
mineral and examine it under the microscope with an inch object- 
glass, and strongly illuminate it with transmitted lght alone, we 
find that about two-thirds of the particles transmit light, whilst 
the others do not. Now, galena owes its strong metallic lustre 
to its great opacity, and I think we are justified in pronouncing 
that these last particles are galena, and that. those which transmit 
light are blende. The finest film of galena that can be got by acting 
upon an alkaline solution of lead oxide with thio-urea does not 
transmit light, whilst blende obtained artificially by a similar 
method is quite transparent. 

I do not think the analysis in Mr. Argall’s Paper could represent 
very pure specimens of the minerals. It will be observed that the 
samples procured by me are very uniform in character, except a few 
isolated crystals of pyrites, which can be perceived with the eye. 


TicHBORNE—On an Argentiferous Galenetic-blende. 305 


In the five analyses given in Mr. Argall’s Paper there is a great 
discrepancy of composition ; thus: the lead varies from 7} to 26 per 
cent.; the zinc from 8 to 49 per cent., and, where estimated, the 
silver respectively 4, 6, and 74 ozs. ‘This great variation in com- 
position is easily understood when we note the iron; for we find 
that one sample, marked “ EH,” must have contained about 23 per 
cent. of pyrites; sample “A” 32 per cent., and sample ‘‘C” more 
than half pyrites. 

The samples examined by me contained more silver than thie 
highest estimation given in these analyses. 

In concluding this short notice of this ore, am tempted to 
quote from my report upon the Dublin International Exhibition of 
1865.1 In giving the statistics of the raising of silver in Ireland 
I stated that this county was a large supplier of the valuable metal, 
but I am afraid to make the calculation now which I did at that 
period. I then stated that Ireland produced 14,000 ounces of 
silver per annum, or 2°4 per cent. of the whole of the silver raised in 
the world, and its value might be estimated at £3,850 per annum, 
exclusive of the lead raised at the same time. If 1,000 tons of this 
argentiferous ore can be sighted, which represents of silver alone 
8,000 ounces, how lamentable it seems that this valuable industrial 
resource should remain unworked—mere earth which might be 
transmuted into bone and sinew. 


1 Chemical News, July, 21, 1865: Report upon the Dublin Exhibition, and Official 
Report, by C. R. Tichborne. 


SCIEN. PROC. R.D.§.—VOL. IY. PT. Vi. 2K 


[ 306 | 


XXXIV.—NOTES ON SOME OF THE IRISH CRYSTALLINE 
TRON ORES. By G. H. KINAHAN, M.R.LA., &. 


[Read, April 21, 1884]. 


Parr I, 


A quxstion that appears to attract some attention in America at 
the present time is “The Genesis of the Crystalline Iron Ores” ; 
therefore some notes on the lodes and accumulations of these ores 
in Ireland may be of interest. 

These ores, excluding the carbonates, occur in lodes and in 
interbedded masses, generally lenticular and irregular. Formerly 
they were extensively mined in Ireland; but after the last furnace 
was put out, about 230 years ago, and those operations had ceased, 
most of the pits and accompanying works were covered up, so that 
the sites of many of them are now unknown. A few, however, of 
these ancient works have of late years been re-opened, while in other 
places deposits have been discovered and worked, so that from these 
later workings we can learn something about the nature of the 
deposits now in question. 

Such ores are due to the decomposition of organic matter and 
carbonic acid. Chalybeate water contains iron, either as the sul- 
phate or as the carbonate. When iron exists as the sulphate it has 
been derived from the decomposition of pyrite in the rocks through 
which the water has percolated ; the iron in solution is oxidized on 
exposure to the atmosphere, and a certain proportion of it is de- 
posited. The source of the iron, besides the sulphides, may be 
lodes or such like accumulations, and also the leaching out of the 
iron colouring matter of the rocks and clays. Le Conte thus 
describes the reactions that accompany the decomposition of organic 
matter :-— 

“Decomposition of organic matter isa process of oxidation. In 
contact with peroxide of iron (ferric oxide) it deoxidizes and becomes 
reduced to protoxide (ferrous oxide). The acids, especially carbonic 
acid, produced by decomposition of the organic matter, then unite 
with the protoxide, forming carbonate of iron. The carbonate, 
being soluble in water containing excess of carbonic acid, is washed 


Kinanan—On Some of the Irish Crystalline Iron Ores. 307 


out, leaving the soil or rocks decolourized, and the iron-charged 
waters come up as chalybeate springs. But the ferrous carbonate 
rapidly oxidizes again in the presence of air, by exchanging its 
carbonic acid for oxygen, and returns to its former condition of 
ferric oxide, and is deposited.” ? 

On account of these reactions, deposits of ferric oxide are found 
about iron springs, along the streams that flow from them, and in 
low places where their waters are collected. This is what usually 
takes place, but not always; for if the iron water accumulates in 
the presence of an excess of organic matter, such as peat, all the 
iron cannot be reoxidized, but must remain in the form of ferrous 
carbonate.” 

“Thus there are two forms in which iron leached out from the 
soils and rocks may accumulate, viz., ferric oxide and ferrous car- 
bonate. ‘The former is accumulated where the organic matter is in 
small quantities, and consumes itself in doing the work of dissolving 
and carrying the latter where the organic matter is in excess.” 

The recent, or the more or less superficial, accumulations of iron 
ores may be first described. In some of the estuaries and lagoons 
earthy iron ore or some other ferriferous strata are deposited. In 
the estuary or lagoon of the Slaney (Wexford harbour) the muds 
are often ferriferous. In some places the ferriferous muds become 
richer toward the upper part, and are often covered by a thin seam 
or layer of ferric oxide, above which is mud. This arrangement 
would seem to suggest that the iron came down the Slaney, partly 
in solution and partly in suspension, it being supplied by the de- 
composition of the pyrite in the Cambro-silurian and Carboniferous 
argillaceous rocks and the leaching out of the colouring matter from 
them and the Cambrians. The lands of the “intakes” of other 
estuaries are often in part ferriferous, with seams or disseminated 
particles of iron ore in them. 

It is principally during winter floods that the muds accumulate 


1 Other authorities ascribe it to a decomposition of the salt, the carbonic acid 
escaping, while water and oxygen take its place, thus forming a hydrous ferric oxide. 

* At the bottom of some of the Irish bogs there is ‘‘ stone turf,’’ more or less im- 
pregnated with some of the sulphate or carbonate of iron, or both combined. If only 
the latter is present when the turf is first cut, it is not iron-stained, but after it is dried 
it is found to be full of little particles of the ferric oxide, the turf becoming more or 
less ‘‘iron-marked.” 


2H 2 


308 Scientific Proceedings, Royal Dublin Society. 


but it is during the summer heat, when the water is shallow, that 
the iron is deposited, partly by the ore being concentrated by 
evaporation, and partly by the chemical agencies already mentioned, 
which precipitate the soluble carbonate and sulphate, having more 
power to operate. For these reasons we should have first plain 
mud, then ferriferous muds with seams of ore, and then the same 
alternations repeated. 

At times the iron-ore would be in excess, as whether the ore in 
solution be either the carbonate or the sulphate, when the waters 
are low and heated a quantity of the ferric oxide is deposited in 
the shallow pools and along the beds of the rivers and their tribu- 
taries, which stores are brought down by the first series of floods to 
be deposited in the estuaries or such like still waters. 

The Ovoca river, county Wicklow, and such like rivers, which © 
receive mine drainage, carry down in suspension and in solution a 
vast quantity of iron, to be afterwards deposited along the lower 
parts of their courses and in their estuaries and outside in deep 
water. Ferriferous river water also deposits iron in the lakes and 
loughauns through which it passes. 

If, however, the loughauns and pools are shallow, the ore is 
generally washed out of them by the autumnal and winter floods. 
The stream that flows northward along the Maum valley, county 
Galway, gets quite thick and turbid during the summer heat, while 
a quantity of the ferric oxide is deposited in the pools, to be washed 
out of them and carried away by the subsequent floods. 

It is a remarkable fact in connexion with the ores in the allu- 
vium of the Irish rivers, that these old deposits are often of con- 
siderable thickness and extent, such not being the case with the 
recent ones. ‘Those thick deposits are now nearly always covered 
with a greater or less thickness of alluvium. ‘These peculiarities 
may possibly be due to the leaching out of the colouring matter of 
the rocks having been more active formerly; that matter having 
been removed to such a depth, the leaching now goes on very 
slowly. 

Bog iron ores and ochres, although found in the alluvium of 
lakes and rivers, are very often associated with peat or peaty accu- 
mulations, and in general occupy hollows or nearly level surfaces ; 
but not always, as some occur on hill slopes. When in hollows 
and on flats the overlying bog may be due to the iron ore having 


KINAHAN 


On Some of the Irish Crystalline Tron Ores. 309 


formed an impervious floor, on which mosses, lichens, grass, hea- 
thers, &., grow and decay. Such peat accumulations are neces- 
sarily thin, as the iron ore floor is not congenial to the rapid 
growth of bog. 

At the present day the ore that is being formed at the surface 
is usually ochre, the bog iron ores being beneath greater or less 
thicknesses of surface accumulations. The latter is always more 
or less argillaceous, but in some places the surface is a rich 
granular ore of apparently a newer growth. 

It may be observed in Ireland that where these ores occur asso- 
ciated with peat, the bog areas usually lie on more or less pyritous 
rocks, such as the black coal-measure shales, the calp shales, and 
black limestones, and the pyritous metamorphosed rocks; and these 
appear to have been in a great measure the source of the bog iron 
ore. ‘This, however, is not always the case, as the iron garnets, the 
ferriferous micas, hornblendes, and pyroxenes, &c., in some rocks 
rapidly decompose, and are a considerable source of the ferric oxide; 
while in parts of Ulster there is a sub-metamorphosed sandstone, 
which, with its associated schistose rocks, supply extensive accumu- 
lations of ochre. ‘These sandstones weather very rapidly, and in 
general to considerable depths—some, indeed, have all their cement- 
ing materials washed or leached out of them, leaving a residue of 
more or less pure sand. ‘The normal colours of these sandstones 
seem to be different shades of green, or bluish-green; but these 
rapidly and deeply weather into a brownish iron-masked rock, with 
a thin dirty-white crust or surface. Besides the direct leaching of 
the soil or rocks, there are in places chalybeate springs which supply 
hydrous ferric oxide from more or less deep sources. The ochre 
forms a greater or less mound, or perhaps a sheet, round such 
springs; or may well up through boggy land, thus forming a 
ferriferous boggy swamp. 

These bog iron ores and those allied to them, which have been 
briefly described, have accumulated at or near the surface. There 
are, however, in many of the rocks forming the surface, fissures, 
joints, cracks, and such like openings, into which portions of the 
iron in solution must flow to form deposits in cavities below the 
surface. Such seems to have been one of the sources in the case of 
the Antrim “pebble ore” described in the second part of this 
Paper ; while in other places the leakage from younger strata, seems 


310 Scientific Proceedings, Royal Dublin Society. 


to have supplied the material for the iron ore now found in the 
underlying or older beds. Thus the iron ores in the Carboniferous 
limestone may have permeated downward during the formation of 
the Coal-measures; the Silurian iron ores during the formation of 
the Carboniferous rocks, &c., &e. Such a theory, however, will not 
account for all of the iron ore accumulations, as will appear from 
the brief descriptions given in the second part of some of the Irish 
lodes and other accumulations. 


Parr IT, 


In the first part of this Paper we drew attention to the iron 
ores in the surface accumulations, and their probable mode of for- 
mation; while in this it is proposed to refer more specially to the 
lodes, and such like, in the older rocks, accompanied with sugges- 
tions as to the possible sources from whence the iron may have 
come, beginning with the Tertiary Iron Ore Measures of the 
county of Antrim. 


Antrim [ron Minzs. 


The Tertiary dolerites of the counties of Derry and Antrim, con- 
tain interbedded Iron Ore Measures. These appear to have been 
lacustrine deposits, which accumulated in shallow lakes or ponds of 
water, in hollows on ancient surfaces of the lava sheets, to be sub- 
sequently covered up by newer sheets of the dolerite. When fully 
developed the members of these measures are :— 


1. Lithomarge, or laterite, with inliers of bole 
. Ochreous rock (Pavement). 

. Bole, or alumnious ore (second ore). 

. Pisolitic, or pebble ore (first ore). 

. Steatitic rock (Brushing). 

. Steatitic clay (Holing). 

. Alumite (or alum clay). 

. Lignite. 


GBA Doe © LH 


The lignite and alumite’ occur only near the margins of the 
different. basins, wholly, or in part, replacing the iron ores (3 and 4). 


1 Alumite is somewhat similar to the French clay called Bauxite, and is often so 
named. 


KinaHan—On Some of the Irish Crystalline Iron Ores. 311 


No. 1. Lithomarge.—This is in part a methylotic rock, as it is 
usually more or less steatitic. It probably consisted, at first, of 
muds formed from the weathering of the exposed surfaces of the 
dolerite, its constituents having been carried into the lakes by rain, 
rivulets, and wind. In it there are beds and lenticular masses of 
bole, sometimes rich enough to be worked as iron ore; the normal 
lithomarge representing the wash of continuous rains or the drift 
of continuous or heavy winds, while the beds of bole may be the 
wash aiter long periods of drought. In the lithomarge are blocks 
of dolerite with the outer parts decomposed to a slight depth. As 
these may occur at some height above the base of the lithomarge, 
it is not very easy to account for their appearance. (See Pl. xvii., 
Scientific Proe., Roy. Dub. Soc., vol. iii., new series). This theory 
for the formation of the lithomarge will not be received without 
dispute. My son, Gerrard A. Kinahan, who has examined it very 
carefully, believes that it cannot be a sedimentary rock, but that it 
is evidently a methylotic dolerite formed in situ. In favour of this 
theory he refers to the dolerite blocks in it, and the amygdaloidal 
portions; but apparently against this theory are the inlying beds 
and lentils of bole, with thin seams and bits of lignite—the amyg- 
daloidal portions are at the surface of the underlying dolerite flow. 

No. 2. Ochreous Rock.—This lies conformably on the lithomarge, - 
forming its surface, and is called the pavement, because it is the 
floor of the iron ores. The surface of the pavement has been 
denuded. There seems to have been a break in the course of opera- 
tions, as the measures above it were deposited under different con- 
ditions to those below it. Before, however, describing the iron 
ores (Nos. 3 and 4), we will turn our attention to the alumite and 
lignite. 

Nos. 7 and 8. Alwmite and Lignite—Theserocks, although placed 
uppermost in the list, seem to be older than the iron ores, having 
accumulated more or less contemporaneously with the lithomarge ; 
they being littoral accumulating while the lithomarge was deposited 
in the deeper water. ‘The alumite appears to have been originally 
lithomarge; but as the bog (now lignite) extended out over the 


1 As in some cases, the lignite was forming at the margin of the pools, while the litho- 
marge was accumulating in the deeper portions. It is probable that some of the iron 
ore in these boles had its origin in the leaching by the lignite of the colouring matter 
from the lithomarge, as seams and pieces occur in the bole, but not in the latter. 


312 Scientific Proceedings, Royal Dublin Society. 


lithomarge, it leached the iron out of it, and left a residuum of 
alum clay; consequently the upper portions of the beds are richest, 
while in depth they graduate into lithomarge. At first lithomarge, 
alumite, and lignite gradually filled up the lakes; next, these ac- 
cumulations were covered over by a flow or flows of dolerite, the 
steatitic rocks (Nos. 5 and 6) being the tuffose and decomposed 
underneath portion of the flow. 

Nos. 3 and 4. Bole or Alumnious Tron Ore (2nd ore), and the 
Pisolitie or Pebbly Ore (1st ore).—We have next to consider how 
these ores accumulated between the lithomarge and dolerite. It 
would appear evident that they are younger than the overlying 
bed of dolerite, for the following reasons : first, coming up through 
the iron ore measures in the Glenariff mines, as mentioned by Mr. 
P. H. Argall,' there are nearly perpendicular dykes bearing about 
N. 15° W. These are thus described :—‘ These dykes may be 
divided into two distinct classes: first, those which stop at the roof, 
or stop dykes, and second, those that penetrate the roof, or through 
dykes; the latter invariably displace the ore measures, and bake the 
pisolitic seam, while the “stop dykes”’ neither displace nor bake the 
seam. ‘The dykes that stop at the roof have a steatitic parting 
separating them from it, similar to that above the pisolitic ore.” 

Some of the “stop dykes” turn over or “splash” against the 
roof, which goes to prove that they are newer than it; while the 
“through dykes” in general can be traced up to the sheet of dolerite 
to which they belong. “As already stated, the pisolitic ore is neither 
baked nor displaced by the majority of the dykes which stop at the 
roof ; while it is nearly always displaced and indurated by the dykes 
which penetrate the roof; from which it would appear that the 
pisolitic ore was formed prior to the latter and subsequent to the 
former.” 

The pisolitic ore has larger pisolites and is richer at the surface, 
the richness and size of the pisolites decreasing downward gradually, 
till it merges into the bole, which often is too poor to be profitably 
worked. ‘The ore seam (Nos. 8 and 4) is of very irregular thickness, 
asin some places the roof descends until it rests on the “‘ pavement,” 


' Scient. Proc. R.D.S., vol. iii., new series. Mr. Argall, late resident agent of the 
Glenariff mines, has examined the iron ore measures very carefully, and from his notes 
we will quote frequently. 


Kinanan—On Some of the Irish Crystalline Iron Ores. 318 


or there are hollows and pot-holes in the latter, or the pisolitic ore 
may be absent, the roof resting on the bole, or the latter may be 
absent.? 

From the facts that have been stated, it seems evident that the 
iron ore seam must be considerably younger than the overlying 
beds, and that it occupies a shrinkage fissure, this fissure being due, 
probably, to the drying and contraction of the lithomarge, the 
latter shrinking away from the steatic bottom of the dolerite ; while 
toward the margins of the basins the lgnite, in general, shrank 
away from the alumite, as between them a thin bed of iron ore 
occurs in places.” Into this fissure the iron ore, in part, as sug- 
gested by Mr. Argall, found its way in solution; but at the same 
time it was probably considerably augmented by the iron leached 
from the lithomarge during its change into alumite. 

To me it would appear that the above is the most plausible way 
of accounting for the occurrence of the iron ore seam, as it lies uncon- 
formably on the “‘ pavement,’ while the ‘‘ stop dykes” are evidently 
younger than the latter, while they are older than the seam. It is 
also worthy of note that these “stop dykes’ act very similarly to 
the cross courses, heaves, and the like, that cross a standing lode, 
as in such cases the seam is much thicker and richer at one side of 
the eross course than at the other. This thickening of a stranding 
vein at one side of cross courses has not, as yet, been satisfactorily 
explained; but probably it is due to a somewhat similar cause 
to that which thickens the horizontal Antrim lodes. 

If the above theory as to the formation and growth of the 
horizontal iron lode is correct, it can easily be imagined how iron 
ores may have accumulated in other places. They may have come 
down in solution from the surface, or water may have leached rocks 
as it passed down through them, the ore subsequently being de- 
posited in fissures and other vacancies. 

Here we may draw attention to the gossan of the Ovoca mines, 


1 From a conversation with Walter Jameson, Esq., the resident director of the 
Fglintoun Chemical Company’s Works, Glenarm, &c., I am led to believe that his 
theory as to the formation of the alumite and associate beds is very similar to, if not 
identical with, that given above. 

2The late W. Jory Henwood, in his description of the Cornish and other mines, 
has satisfactorily proved that the ‘‘lay and lay,’’ or horizontal interstratified lodes, 
occupy cavities due to the irregular vertical shrinkage of beds, or parts of beds. 


314 Scientific Proceedings, Royal Dublin Society. 


county Wicklow (hereafter to be described), as it shrunk away from 
the underlying sulphur lode, forming a horizontal fissure, which 
in part remained open (if we except the water that was in it), 
while in part it was occupied by a “ gossan lode.” As the latter 
contained minerals not a trace of which has been found in the 
normal lode, they suggest that the gossan lode was filled from above 
by foreign minerals in solution: this “gossan lode,” therefore, 
seems to have been filled somewhat similarly to the horizontal iron 
lodes of the county of Antrim. In the latter case the boggy water has 
leached the iron out of the dolerite ; while, as mentioned by Argall, 
in places on the surface, where the bog water comes in contact with 
the dolerite, beds of bog iron ore are forming. It is worthy of note 
that where the “through dykes” cut the pisolitic, the latter is often 
changed into magnetite. 


DysErt aND DuNAMASE, QUEEN’s County, witH KiILcoLMAN 
AND SHANAGOLDEN, County oF LIMERICK. 


_ At these Queen’s County and Limerick localities there are old 
mines and veins of limonite mixed with hematite. At Dysert 
there are the remains of old workings that cannot be properly 
examined. In one place the ore seems to be in a mass of “ fault- 
rock,”’ and in another in a cave; and in the first place hematite is 
interstratified with shale. At Dunamase there is an untried vein. 
At Kilcolman silicious limonite occurs in an irregular mass, while 
at Shanagolden it is in “ fault-rock.” In both counties the ores 
occur in the Upper Limestone, close below the base of the coal- 
measures. ‘The production of the iron ore may possibly have been: 
due to the decay of the pyrites in the overlying coal-measure shales; 
as from this sulphate of iron would be formed and an insoluble 
hydrated peroxide of iron—the first to pass off in solution, the 
latter remaining to form the mass of ore. Or the peroxide of iron 
may have accumulated in the limestone caves simultaneously with 
the deposition of the coal-measure shales, a part of the clay also 
being carried down to form the shales in the ore, a part of the iron 
present going to form the ore and another portion the pyrite; or 
both processes may have occurred in turn. 

Some distance to the southward a cave was discovered in the 
Ashford limestone quarry. It is on the same geological horizon 


Kixanan—On Some of the Irish Crystalline Iron Ores. 315 


as the ore at Kileolman. It dips under the coal-measures, and 
when first opened it contained a thick deposit of slightly ferriferous 
cave earth. A chalybeate stream occupies it during part of the 
year; but as the water does not deposit any iron in the cave, the 
iron must be accumulating in some subterranean cavity, or the 
water must come to the surface a good distance away in a chaly- 
beate spring. 


CountTIES oF CorK AND WATERFORD. 


These counties were once famous for their iron mines; but 
although it is easy to find the sites of the forges and iron mills, the 
old workings are unknown, or cannot be examined in their present 
state. These mines seem to have been principally situated in the 
Yellow Sandstone ground, but some were in the Old Red Sand- 
stone, and others in the Carboniferous Slate. 

Some of the iron ores appeared to occur as the gossan back of 
copper lodes, but others have all the appearance of being indepen- 
dent lodes. At Glandore, county of Cork, there is a limonite back 
to a copper lode. This lode is remarkable, as the present ‘“‘ mineral 
channel” was first a brecciated “ fault-rock,’’ in which fissures 
opened that were filled by the copper lode ; while, after the iron ore 
back had formed, a second system of fissure opened in the iron ore 
and the associated breccia, which are now occupied by manganese 
ores. 
At the west end of Bear Island there is a standing lode of 
hematite, about eight feet wide, in the Carboniferous Slate ; while 
elsewhere there are many smaller and usually irregular veins and 
strings of hematite, ofter the micaceous variety. These veins seem 
to be best developed in the areas where there are Intrusive Rocks. 

As these veins occur below the black shales of the Carboniferous 
Slate group, it is possible that the ore may have had its genesis from 
the pyrites [in them, or it may have welled up from below, it 
being in part the leaching of the underlying purple and red rocks 
of the Upper and Lower Old Red Sandstone. 

Tt should be pointed out that there was a centre of vulcanicity 
in the neighbourhood of Berehaven during the accumulation of the 
Carboniferous Rocks, which probably had some kind of connexion 
with the development of the iron ore strings and veins. This action 
also seems to have had something to do with the accumulation of 


316 Scientific Proceedings, Royii Dublin Society. 


the copper ores ; because at Allihies, near the whinstone intrusions 
the ore is concentrated in large lodes, while elsewhere in the county 
of Cork the ore is in more or less small and numerous veins, or 
disseminated in particles in the rocks of the Yellow Sandstone 
(Griffith) group. 


CounTIES OF WEXFoRD AND WICKLOW. 


In these counties, besides the old workings, of which very little 
ig now known, there are the iron ore backs to the pyrite lodes of the 
Ovoca mines; while in the purple and green Cambro-silurian slates 
there are irregular cakes or lentils and strings of iron ore. 

Here the central member of the Cambro-silurians is made up of 
interstratifications of whinstones, felstones, tuffs, limestones, and 
schists, while above and below these there are the upper and lower 
red and purple slates. Many of the limestone and the calcareous 
schists are impregnated more or less with carbonate of iron, some, 
indeed, being poor iron ore (chalybite) ; while in the red and purple 
slate, but especially those of the upper zone, there are cakes or lentils 
of limonite and strings of hematite. 

The cakes of limonite are of irregular shapes, and are probably 
due to chalybeate springs that welled up while the clays were 
accumulating ; their source being in the underlying ferriferous 
limestone; while the strings of hematite seem to be connected with 
vuleanicity, being due to steam that penetrated the cracks and 
joints, leaching the colouring matter out of the adjoining portion of 
the slates. In favour of the latter suggestion we find in other 
places, near intrusions of irruptive rocks, that similar strings of 
hematite are developed; while the newer granite (Carboniferous) 
causes the adjacent rocks to be “iron-masked.” 

At the Ovoca mines, between Ballycapple to the N.H. and 
Knockmohill to the S.W., the gossan backs to the lodes are, in 
general, ochre or limonite; while in places, but especially near 
heaves, the latter may be associated more or less with manganese, 
chalybite, and magnetite. The limonite was deposited in horizon- 
tal courses; but afterwards, when drying, it shrank away from the 
normal lodes, leaving vacancies, some of which remained open as 
large vugs, while others were filled with the “ gossan lodes” already 
described. It is remarkable that the rocks adjoining the main 
mineral channel are “ iron-masked” (ochreized), similar to the rocks 


Kinanan—On Some of the Irish Crystalline Iron Ores. 317 


adjoining the intrusions of the Carboniferous (?) granite; which 
may indicate that these outbursts and the lode are of similar age. 
Descriptions of other places in Ireland where these iron ores 
were worked would be little more than repetitions of what has 
already been said, as we could only mention of the county of Clare, 
that there were formerly extensive mines there; some, such as those 
of Ballymalone and Bealkelly, being on cakes of ore, like those 
in the county of Wexford—Cambro-silurians ; and of the counties 
of Longford, Roscommon, Fermanagh and Tyrone, that the iron- 
workings there are in the Carboniferous Limestone, &c., &c.; that 
the old workings are now inaccessible, while the new lodes have 
not been sufficiently investigated to afford much information. We 
may, however, mention that at Knocksnaghty, county of Clare, and 
in other places, graphite, associated with iron, occurs in true veins. 


XXXKV.—NOTES ON THE EARTHQUAKE THAT TOOK PLACE 
IN ESSEX ON THE MORNING OF APRIL 22, 
1884. By G. H. KINAHAN, M.R.I.A., &e. 


[Read, June 16, 1884.] 


Descriptions of this earthquake have already appeared in the 
various daily papers and the scientific journals, but there are cer- 
tain phenomena connected with it that as yet have not been de- 
scribed, and the principal object of this communication is to draw 
attention to such. 

The disturbances in the area of structural damage took place 
between 9.15 and 9.20 am., April 22nd, the damaged structures 
being nearly all found in a tract southward of Colchester. From 
this tract, as a centre, the shock seems to have been felt for nearly 
equal distances in the surrounding country; northward it is re- 
corded in the valley of the Humber; N.-W. at Liverpool, and 
westward as far as Bristol. To the 8. and H. its conspicuous limits 
were the sea coast, but slight shocks are said to have been felt east 
of the Straits of Dover, at Ostend and Boulogne. 

The tracts in which the maximum damage was done are five in 
number and more or less isolated; they, in the order of intensity, 
are as follows:—l, Wivenhoe; 2, Peldon; 3, Abberton and 
Langenhoe; 4, Colchester; and 5, West Mersea; all except 
the first being north of the estuary of the Blackwater, and west of 
that of the Colne. Associated with these centres there are mar- 
ginal tracts in which much damage occurred, but less than in the 
maximum areas, while in the adjoining county more or less damage 
was done at isolated places as follows :—South of the Blackwater, 
in the vicinity of Bradwell, and at Tillmgham; to the westward 
at Bishop (N.-W. of Maldon), Witham, Braintree, Stisted, 
Coggeshall, and Oldham; to the north at Nayland; to the north- 
eastward at Bromley Hall, Ardleigh, Dedham, and Manningtree ; 
while eastward, toward the Naze, although it was felt, no damage 
seems to have been recorded. 

Before proceeding further with the descriptions of the areas, it 
is expedient to give brief descriptions of the building materials 
used in this portion of Hssex, and peculiarity of the structures that 


Kinanan—On the Earthquake in Essex. 319 


seem to have assisted in their destruction, beginning with the 
materials, which may be generally divided up as follows:—Ist; 
brick; 2nd, stone; 3rd, lath and plaster; and 4th, sheiling or 
wood. 

1. Brick Buildings.—Some of these are what are called ‘“ frame 
houses,” being bricks in wooden frames; but they are not common 
in the affected area, and none of those remarked appeared to be 
damaged. The other brick structures suffered severely, especially 
chimneys. The old houses in general have more traces of the 
quake than the new, but not always, as in North Wivenhoe both 
were nearly equally injured. ‘The styles of the brick buildings 
seem to facilitate their coming down. Low structures have often 
long thin. chimneys plastered against higher ones, without any 
binding or clamps, many of which fell down, doing considerable 
damage. In other places the tall houses are without gables, the 
chimneys coming up through a high, sloped roof, which necessitated 
their being of a greater or less height, and many of these came down, 
if square, or if their greatest width was transverse to the direction of 
the shock; if we may judge by what can be seen outside the limits 
of the affected areas, many of the mouths of the chimneys, which 
were built of single bricks, were cracked and belled at their mouths 
from the heat in the flues, and consequently easily came down. 
Many of the walls that came down were two bricks in thickness, 
they having been run up without binding the outside ones to those 
inside; while the regularly built and bonded walls stood in all 
cases; also the mortar used in building seems to have been of a 
very poor quality. Many of the cracks in these structures are in 
donnexion with opes, such as windows and doorways: some, how- 
ever, are quite independent of them. The most interesting cracks 
are those in the chimneys, especially where the tops of the latter 
are partially turned round. 

2. Stone Structuwres.—The major portion of these only occur in 
the church towers, and in some cases are much older than the asso- 
ciated churches. Some of these old towers suffered severely, which 
cannot be much wondered at. Takeas an example the Langenhoe 
tower, which was old, rotten, and cobbled ; and here the major por- 
tion of the damage was due mostly to its fall, but not solely, as the 
cracks through the wall of the nave and porches are due to tie 
earthquake. At Peldon, however, the damage was mostly due 


320 Scientific Proceedings, Royal Dublin Society. 


to the quake; for, although the tower in part fell, the chancel— 
which is said not to be more than forty years old—is considerably 
injured. Old roofs, such as that on Little Wigborough, lost their 
tiles. In Colchester a portion of the spire of the Congregational 
church came down. ‘This, however, was not very remarkable, as 
the portion severed from it was a patch that had been added on 
account of damages from a storm. 

3and 4. Lath and Plaster and * Sheilings,”’ or Wooden Houses.— 
These are varieties of ‘frame houses.” In the first the frames 
are lathed and then plastered, while in the latter the frames 
are covered with thin wooden slabs or slats. As these classes of 
houses can vibrate, especially the second, they suffered very little, 
except some very old ones, from which the plaster or slabs were 
shuken down; many of them, however, had stacks of brick chim- 
neys that fell and did considerable damage. 


GroLtocy oF THE AREAS OF SrructuRAL DEsTRUCTION. 


From the geological map by my colleague, Mr. W. H. Dalton, 
we learn that their different areas are on, or at the margin of, ex- 
posures of the London clay, while rarely has any damage occurred 
on the younger accumulations. ‘The destruction on it, however, is 
confined to more or less small limited defined tracts. In connexion 
with the geology, it may be mentioned that the evidence would 
seem to suggest that the shock does not appear to have travelled 
from one of the intensely affected areas to another, but that it was 
in action in all at one and the same time, travelling in each in more 
or less different directions, which, as pointed out by Dr. Taylor, 
of Ipswich, seem to be due to the diversion of the shock by lines 
of faults or breaks in the continuity of the strata. 

Wivenhoe.—This lies immediately N.E. of a part of the, es- 
tuary of the Colne, the intense shock having affected a very small 
tract which is margined to the southward by the break of the Colne 
river valley (N. 75° W.); and adjoining this line the shock was 
very severe, while it gradually decreased in intensity towards the 
N.E., as a mile to the N.H. the houses in the north portion of the 
village of Wivenhoe Cross were not injured. Hastward, in the 
Alresford district, the damage was very slight compared to that at 
Wivenhoe; also to the west of the water at Rowhedge, although in 


Krvanan—On the Earthquake in Essex. 321 


the northern portion of the latter a good number of houses were 
more or less wrecked. It is worthy of note that the railway cutting 
appears to have modified the shock, as the houses adjoining it, 
both to the south and north, scarcely suffered. Here, as previously 
mentioned, the new houses were wrecked as much as the old, espe- 
cially those near the Hall, to the north of the railway. 

The most ruined portion of this village is on the narrow outcrop 
of London clay at the margin of the glacial drift, but at the same 
time all the other structures that were injured are on the latter, 
and some of these received considerable damage. 

The shock evidently came from the N.N.H., but when it met 
the break of the Colne river valley it seems to have recoiled, or in 
part collided along it, thus causing additional destruction in the 
vicinity of the river. The narrow band of London clay also ap- 
pears to have had some sort of connexion with the maximum 
damage done, as in places it appears to have travelled in it under 
the younger accumulations. This is also suggested farther north- 
ward, as between Colchester and Ardleigh there are narrow tongues 
of London clay, the houses on which were injured while those on 
the newer gravel were not, except in one instance. 


PrELpon, ABBERTON, AND LANGENHOE DisrTRICcvT. 


In this locality the structural damages occurred in a rather 
considerable-sized N.E. and S.W. tract, between the marches of 
the Mersea and Pyfleet creeks on the 8.H. and the valley of the 
Lagen river on the N.W., and extending from Fingrinhoe on the 
N.E. to Virley on the 8.W. ‘To the N.E., at Hornwood, the 
damages were slight, although it is close to both Wivenhoe and 
Rowhedge, but divided from them respectively by the breaks of 
the Colne and Roman rivers valleys; while to the S.W. the 
destructive action gradually decreases until eventually it died out 
before Tolleshunt Knight was reached. At Virley the action is 
interesting, as this village is only separated from Saleot by a small 
narrow EK. and W. creek, yet the houses in Virley, most of them 
comparatively new, are damaged; while those in Salcot, which are 
old and frail, were not affected—all this tract, except a small 
portion near Fingrinhoe, is on the London clay. To the south- 
ward of Virley, in a line running about E.S. EH. by H. from Tolles- 


SCIEN. PROC. R.D.S.—VOL. 1V. PT. VI. 2 


322 Scientific Proceedings, Royal Dublin Society. 


hunt Darcy,.a little damage was done, the injured structures being 
on the margin of the London clay. 

Peldon, Area of excessive Damage.—This extends W.N.jW. by 
W.,and E.S8. E. by E., being bounded northward and southward 
by small stream valleys, the maximum damages having taken place 
at the southern and western margins. In this area the effects would 
appear to suggest that the shock had a sort of rotary motion; the 
main direction, however, seems to have been southward, and the con- 
cussion against the lines that form the southern and western boun- 
daries appear to have caused the great destruction in those places. 
The twist in the direction of the shock in the vicinity of the south- 
ern boundary is exemplified by the twist in the chimney of Strood 
mill, and in the damages that have been described as happening to 
Dr. Green’s house in the same vicinity. A well near Peldon is said 
to have become quite muddy. 

Abberton and Langenhoe Area of excessive Damages.—This tract 
extends about N.N.E. and 8.S.W., its southern boundary being 
the small stream valley that bounds the Peldon area on the 
northward. The maximum damage seems to have happened in 
the vicinity of Abberton, where the well is said to have remained 
muddy for a few days. The shock appears to have been rotary, 
but the general direction would seem to have been from the 
southeastward, having concussion shocks from the boundaries, 
which might account for the rotary appearance and the twisted 
action observed at Langenhoe, where the church and glebe house 
suffered considerably. 

To the N.E., at Fingrinhoe and Frenchman’s Lane, the struc- 
tural damages margin the tract of glacial drift previously refer- 
red to. 

Colchester Area.—The maximum damage occurred in a nar- 
row nearly east and west strip along the south Roman wall, 
from Head Gate to the valley of the Colne. South of this strip 
very little damage was done, while northward it rapidly decreased, 
scarcely any damage occurring north of the Colne river. From 
the geological map by Mr. Dalton we learn that a narrow outcrop 
of London clay occurs along the south wall, widening a little 
towards the eastward, the excessive damage following this widen- 
ing. North of this outcrop the damaged structures are on the 
glacial drift, while on the alluvium at Hast Bridge there are some 


Kinanan—On the Earthquake in Esser. 320 


houses wrecked, although to the southward, at Hythe Bridge, 
houses similarly situated are uninjured.1 The houses at Hast 
Bridge are remarkable, because the direction of the shock seems 
to have turned southwestward at the river, while elsewhere in 
Colchester it seems to have gone nearly N. (N.N.E. by N.). The 
water in the artesian well that supplies Colchester rose, after the 
quake, seven feet, which height it has still kept up. This possibly 
is due to the earthquake rupturing a dyke, or even a thin parting 
of “ fault-rock,” and thereby adding an additional area of chalk 
to that from which the water was previously drawn. 

Scarcely any damage was done in the western portion and 
suburb of Colchester, while southward to the valley of the Roman 
river the isolated houses, &c., damaged, nearly invariably are on 
small tongues of London clay, the principal exceptions being at 
Roman Hill, Middlewick, and Cockwort. Hast of the Colne river 
valley, as elsewhere when the boundary or break of an excessively 
damaged area is. passed, very little damage occurs, the greatest 
being in the village of Greensted and Wivenhoe Park. These 
damaged are on London clay, as also most of them to the N.H. 
along the Crockleford stream valley. 

West Mersea Area.—This portion of the island of Mersea 
seems to have been given more importance than it is entitled to, 
on account of the cracks that opened in it and the springs that 
came up, while in reality the damage done was less than that in 
the country to the northward; also it was altogether confined to 
a small tract. To the 8.W. of the island along the sea road, near 
a slight driit escarpment to the N. and N.W. of SS. Peter and 
Paul’s Well, an EK. and W. crack opened. It is said to have been 
wide enough to put in your open hand and to have been over two 
yards deep. In appearance it was very like the cracks not un- 
common near the escarpments of driit clifis. The well is at the 
base of the cliff, at the margin of the alluvial flat, and has remark- 
ably clear water, which is said to have risen and become quite 
muddy, while a similar phenomenon took place in the pump well 
of the Coastguard Station, a little to the north. To theN. E. of 
this, at Crossfarm, a second E. and W. crack is said to have 
opened, while in two places along it water spouted up—at one 


1 Some houses on the alluvium at Wivenhoe are injured. 
2F2 


324 Scientific Proceedings, hoyal Dublin Society. 


discoloured with red sand, and at the other with yellow. These 
springs are said by the tenant to have lasted for about half an 
hour. About thirty-two paces to the north of this line the water 
in a well rose two feet and became quite muddy. All the people 
from whom inquiries were made agreed in saying that the waters 
in these different places had no peculiar taste or smell. 

The shock seems to have come from the N.N.E., and was de- 
scribed by a boatman coming north across the Blackwater estuary, 
as having first taken the stern of his boat as if he had run on a 
mud bank, and then nearly twisted the rudder out of his hand, as 
if he had cleared the bank. This statement of the boatman as to 
the direction of the shock was confirmed by the Chief Boatman in 
charge of the Coastguard Station and others. 

Of the exact time at which the shock was felt at each place 
nothing satisfactory could be learned, as outside Colchester very 
few people could say their clocks were right; in each village, and 
often in the one house, there being fifteen minutes or more between 
the times registered by the clocks. The bearings of the walls on 
which those that stopped hung, indicate directions. 

The cracks in the walls are also very unsatisfactory, as those in 
one building may dip in different directions or even be at right 
angles to one another; thus between Peldon and Strood Mill the 
majority bear nearly HE. and W. (W:N.W. by W.), and dip 
northward at 40°; but some of these dip southward while 
those of another system run nearly N. and §8., and dip east- 
ward at 30°; also in the Abberton and Langenhoe area they are 
most irregular, both as to direction and dip. At Colchester in 
general the cracks bear nearly H. and W., but some do not; most 
of them have a more or less high angle of dip, and at Wivenhoe 
the greater number are parallel to the river bed (N.N.W. and 
S.8.E.). The cracks in general are from 5 to } an inch wide, but 
in a few places, such as in the Peldon area, they are wider. Inno 
place could I find a trace of the walls having moved up and down 
along the cracks. 

The inhabitants of the different areas of greatest structural 
damage appear to have been so scared that they cannot tell uf 
there was more than one shock. At the following places, how- 
ever, two. or more shocks are said to have been felt :—Mark Tay, 2; 
Maldon, 3; Walton-on-the-Naze, 2; Ipswich, 3 (where it is also 


Krnanan—On the Earthquake in Essex. 320 


said a shock was felt at 11.8 p.m.) ; Sudbury, 2; and Colchester, 
2 or 3. 

In the Peldon area, it is stated by Dr. Green of Croagh and 
the people of the village of Peldon, that a slight quake was felt 
about six or eight weeks before April 22. 


SuMMARY. 


The area of structural damage was limited, but in the country 
surrounding it the shock was felt for considerable distances. 

In the area of structural damages there were smaller areas in 
which the effects were greatest. These smaller areas are distinctly 
margined at two or more sides by well-marked lines, while at one 
or two of these lines the maximum damage in each occurred. The 
greatest damage was done in the Peldon and Abberton areas. 

In the areas of greatest effect, the shock travelled in different 
directions; yet, in all, the shock appears to have occurred at the 
same moment. 

The geological formations in the area of structural damage are 
“London clay,” “ glacial drift,” and “alluvium.” In two places, 
Hastbridge, Colchester, and at Wivenhoe, damages were observed 
on the latter, while from the north portion of Wivenhoe to Alres- 
ford, and in the northern part of Colchester, damages occur on the 
glacial drift; but elsewhere all damages, especially the greater 
ones, are found on the London clay; while nearly invariably the 
destruction ceased at the margin of the younger accumulation. 


XXXVI.—ON THE BOTANY OF THE RIVER SUIR. By H. CG. 
HART, B.A. 


[Read, May 21, 1883.] 


TuE river Suir takes its rise in the northern flanks of the Devil’s 
Bit Mountain (1583 feet), in the northern part of the county Tip- 
perary. Through this county it runs in a southerly direction to 
Neweastle, on the north of the Knockmealdown Mountains, at the 
borders of Tipperary and Waterford. From this point, running at 
first north to Clonmel and then east to the Waterford estuary, it 
is the southern boundary of Tipperary and Kilkenny and the 
northern of Waterford. The estuary may be said to terminate at 
the junction of the Suir and Barrow, about six miles below Water- 
ford. From this point the tide, however, reaches upwards to a mile 
and a-half above Carrick, a distance of about twenty-eight miles. 
From its source to the Barrow junction the Suir is about 120 miles 
in length. I did not examine the stream below Carrick, which is 
nineteen miles above the Barrow junction. From Carrick the river 
is tidal and the banks disagreeable for pedestrianism, while the 
botany is, I believe, fairly well known. 

Accompanied by a friend, and with average good weather, ans 
_ tour was very agreeable. ‘The scenery is in many places extrentole 
pretty, chiefly near the source, about Golden Bridge, and from that 
to Clonmel through Caher. In some places, as at Knocklofty, 
there is magnificent timber along the banks, while numerous 
ruined castles, abbeys, and mills are met with in the most pic- 
turesque situations. We spent one day on the Devil’s Bit, and 
having found on its north side what we believed to be the Suir, we 
started off with a gay disregard of compass bearings along the 
source of an eastern tributory of the Shannon. At dusk we found 
out our mistake, and made our retreat good to Templemore. 
The following morning, however, we got fairly to work, and kept 
the banks to Carrick in four days and a-half. In a journey of 
this kind the variety and abundance of difficulties to be overcome 
is the chief source of enjoyment. Deep ditches, often crossed with 
the help of an overhanging tree—tributaries, which had to be 


Hart—QOn the Botany of the River Suir. 327 


swam—treacherous swamps, sometimes decoying us to islands— 
and numerous swims, sometimes intentional, sometimes other- 
wise, kept up the excitement. On two occasions only had we to 
leave the immediate banks of the river, which was high during our 
visit—once was for about half a-mile, near Templemore at Loughlin 
Bridge, and the other detour was rendered necessary about eight 
or ten miles below Thurles, where a large tract of low land was 
completely inundated. 

Several rare species were met with. Perhaps the most interest- 
ing was Hriophorum latifolium, which was gathered in one place 
abundantly. New localities and the frequency of some scarce 
plants in unrecorded situations showed that this river had been 
little searched. Many kinds of aquatic birds inhabit the larger 
swamps mentioned above, especially that of Loughmore and the 
river is well worthy of further exploration in this direction. 

I will give an account of my tour from day to day, and 
at the close give a separate enumeration of the rarest specimens 
observed. The river lies from the source to below Loughmore in 
District 7, and from thence to Carrick in District 2 of the Cybele 
Hibernica. 

On the 29th of May, 1882, having left Dublin by an early train 
and breakfasted at Templemore, we made our way through Sir John 
Carden’s demesne to the Devil’s Bit. On old walls at the Priory 
Saaifraga tridactylites and Draba verna were plentiful—two species 
which are frequently seen in company also on sea-side sandhills. 
In low meadows westward Orchis morio and Listera ovata were 
observed. 

On the Devil’s Bit the following observations were made on the 
altitude of plants above sea level :-— 


Art 1500 Fret (Devit’s Bir). 
Cotyledon umbilicus. 
Carex pilulifera. 


At 1400 Frnt (Kizpvurr). 
Ulex europaeus. 
Callitriche verna. 
Lycopodium clavatum. 


Av 1300 Fest (Devit’s Brr). 


Ajuga reptans. 


Ar 1150 Freer (Deviz’s Brr). 


Myosotis versicolor. 


Ar 1100 Fret (Devin’s Brr). 


Listera ovata. 


Ar 1050 Freer (Devin’s Birt) 


Bunium flexwosum. 


Ophioglossum vulgatum. 


328 Scientific Proceedings, Royal Dublin Society. 


These are above the usual vertical limits of several of the 
species. The adders-tongue is remarkably abundant on the 
western slopes of the Devil’s Bit. Nothing else of interest was 
noticed along these hills to the northern extremity of the chain. 
During the detour already mentioned, along a stream which 
proved to be a tributary of the Brosna, flowing west to the Shannon, 
I met with Geum rivale, Alchemilla vulgaris, Sambucus ebulus, Ore- 
pis paludosa, Antennaria dioica, Humulus lupulus, Oarex remota, 
C. sylvatica, Equisetum maximum, and E. sylvaticum. 

The following day, May 30, having driven to Borrisnoe, 
as far as the roads would permit, we crossed country and fell in 
with the stream on the eastern slope of Benduff. On the upland 
pasture ground I noticed Carduus pratensis, Rubus ideus, Lathyrus 
macrorrlizus, Habenaria viridis, and Polystichum angulare. The 
river flows between high and wide clayey banks at its source, and 
soon settles down into a winding, rocky, sandstone bed, amongst 
copses and bluffs of oak, sallow, mountain ash, blackthorn, and 
other shrubby vegetation. For a couple of miles here the stream 
is rapid and very pretty, and hedges are numerous, Carex piluli- 
fera, CO. hirta, C. acuta, and C. remota. with the commoner sorts 
being noted. Valerian and the graceful water avens (Geum rivale) 
also decorate the banks. In this part of its course the river is 
much frequented by water ouzels.. Young and old were continually 
flitting across our path. Near Skehanagh bridge I gathered 
Lycopus europeus, Juncus glaucus, Carex ovalis, and C. paniculata. 
At Killough bridge Humulus lupulus has established itself, and 
here also Hquisetum maximum was observed. Soon after this bridge 
the river Suir, which has hitherto been flowing eastward, turns 
south, and runs a straight and apparently artificial course between 
hedgerows through rich flat lowlands in a slow and uninteresting 
manner. Along here Barbarea vulgaris is very frequent, with com- 
moner grasses, water mint, the larger forget-me-not, and yellow 
iris. Between Knockane bridge and the railway, where the Suir 
comes inside District 2, Epilobium hirsutum, Myriophyllum alterm- 
florum, Potamogeton natans, P. crispus, Carex paniculata, C. vesicaria, 
C. riparia, and Juncus glaucus were met with. 

Several of the species enumerated up to this are additions to 
the flora of District 7. At this point the Great Southern and 
Western Railway is the boundary, and the remainder of my explo- 


Hart—On the Botany of the River Suir. 329 


rations lie in District 2. The river and railway are nearly parallel 
for several miles, and several tributaries have considerably increased 
theformer. Scirpus lacustris first appears now, and Carex vesicaria, 
a local plant, has become common. Another local species, 
Gnanthe phellandrium, afterwards common and characteristic of 
the Suir, first shows itself at Cloon bridge by a small stream flowing 
into the Suir. In its company was Ranunculus heterophyllus, var. 
floribundus. After Cloon bridge Ginanthe is abundant; the early 
fresh green leaves, with their floating lace-work pattern, are very 
beautiful objects. Carex acuta occurs here too, and Nuphar lutea in 
a few places. Other larger water plants appear, as Hippuris vul- 
garis, Alisma plantago, Veronica anagallis, V. beccabunga, and Equi- 
setum limosum. Caltha palustris is not common, and Hupatorium 
cannabinum very scarce. Here the country was much flooded, 
and the river often undistinguishable from the surrounding 
swamps; this was in the neighbourhood of Loughmore. Nymphea 
alba and Polygonum amphibium are very plentiful.  Lysimachia 
vulgaris was met with also—a plant confined to the banks of 
the larger lakes and rivers. Here the river makes a loop to the 
westward, and the banks being quite unapproachable for about 
half a mile, a detour was unavoidable. In the hedgerows I 
noticed Viburnum opulus, Acer campestre ‘and Rosa arvensis. 
Again resuming our walk, or rather flounder, along the side of the 
channel, I noticed Ranunculus lingua and Armoracia amphibia, 
both—especially the former—local in Ireland. Both may be seen 
close to Thurles, which we were now approaching. Oarex vesicaria 
is very frequent near Thurles also. We had been for some time 
travelling in an element which is usually traversed with boats, and 
we were not sorry that nightfall and Thurles came together with 
a cessation of labour. The intermediate stage in a river—that 
between a swift upland stream and a deep and certain lowland 
channel—is often the worst to deal with, as if it was for a time 
uncertain what its destination was eventually to be. In the latter 
part of this day’s walk many birds at their breeding haunts enlivened 
our interests. Sedge warblers, redshanks, wild duck, teal, black- 
headed gulls, and other commoner birds, as well as perhaps some 
rarer ones, inhabit these swamps. ‘This pursuit could not be studied 
without some time spent in boating. 

On the following morning we made an early start from Thurles, 


330 Scientific Proceedings, Royal Dublin Society. 


T should mention that we have so far followed the right or west 
bank of the river. South of Thurles the last three mentioned 
plants and Gnanthe phellandriwm are still frequent. Between 
Thurles and Turtulla Mill I noticed Menyanthes trifoliata, Potamo- 
geton perfoliatus, P. lucens, and Carex riparia. At the Mill the large 
water millfoil, Myriophyllum verticillatum, a rare plant in Ireland, 
was observed ; and between that and Holycross I gathered Ranwn- 
culus lingua, Solanum dulcamara, Alliaria officinalis, and Orchis morio. 
These occurred at intervals along the river to Twoford bridge, and 
along here tributaries and heavy dykes rendered our journey very 
laborious, and we crossed to the left or east bank. We found 
willows overhanging these ditches often very serviceable; and even 
if the bough did give way and capsize the leader into the water, he 
was probably most of the way across at any rate. We had, however, 
determined, to cross all obstacles, so that a swim more or less was 
not important, and up to this the width of the water to be crossed 
was trifling. About two or three miles below T'woford bridge the 
river takes a wide bend westwards, and here there is a deep and 
impenetrable swamp. It was on the margin of this swamp I 
gathered Eriophorum latifolium, a very scarce plant in Ireland, and 
there appeared to be abundance of it. The marsh may be distin- 
guished by the name of Aughakilleen. In the same marsh also I 
noticed Pedicularis palustris, Carduus pratensis, Eupatorium canna- 
binum, Pinguicula vulgaris, Schenus nigricans, and Carea vesicaria. 
In some places the latter was so abundant that as sheets of its leaves 
moved in the wind in the light of a low sun, the effect was that of a 
meadow of shining golden yellow, while as a contrast the glaucous 
foliage of Carex ampullacea gleamed along the flooded fields like 
silver. On the higher land above this marsh Orchis morio is 
frequent, and again lower down about Camus bridge. Here also 
occurred Nasturtium palustre, Lysimachia vulgaris, and Thahetrum 
flavum; and near Castle Lake corn-mill I gathered Potamogeton 
pusillus. On this part of the river’s banks to Golden, Carew disticha 
is frequent. In rich meadow ground on the east bank, a mile or 
two above Golden, I gathered Bromus commutatus, a rare grass in 
Treland. It seemed native in this locality. At Golden, an ex- 
quisitely situated hamlet on the river, we obtained snug, clean, and 
primitive hospitality from two captivating old ladies, in a pictu- 
resque lodge, occasionally used by anglers. The news that Golden 


Hart—On the Botany of the River Suir. 301 


possessed, no hotel at first had filled us with dismay, but we soon 
found ourselves far better off than in an average Irish village 
inn. 

On the Ist of June we made an early start from Golden. Al- 
together the scenery is delightful. Castles, abbeys, and other pic- 
turesque remains of the past abound. A more melancholy feature 
is the number of recently-abandoned handsome dwelling-places. 
Richly wooded and diversified scenery, amongst fertile hills and 
valleys brought us merrily along for the first few miles on firm 
banks on the west side of the river. The most interesting feature 
in the botany here was Orchis morio. It was very abundant, and 
of many hues and great luxuriance. I picked several pure white- 
flowered plants, and one really well-marked variety with the upper 
petals and sepals very dark and the lip nearly white—sweet and 
very large—of it and the white variety I procured bulbs. About 
Golden I noticed Rubus ideus, Saxifraga tridactylites, and Ononis 
arvensis. After a few miles we found it necessary to cross the 
river, which was now about sixty yards wide, with a strong cur- 
rent. Practical experience taught us that this is a little beyond 
the limit of distance which one can swim, holding his clothes dry 
overhead in one hand. ‘The result of this painful experiment was 
that our clothes were mostly soaked for the remainder of the day. 
During the distance between Suir Castle and Cloughabready I no- 
ticed Thalictrum flavum, Ginanthe phellandrium, Sparganium mini- 
mum, and Potamogeton perfoliatus. ‘The banks are now usually 
high and firm, the course of the river is more decided, and neigh- 
bouring swamps are fewer. ‘The result of this is that the larger 
plants are scarcer, and many do not re-appear. On the right or 
west bank of the river, near Cloughabready Mill, I gathered Carex 
paludosa and Scirpus sylvaticus. The latter is very rare in the south 
of Ireland, and scarce in Ireland generally. It was a great 
pleasure to find a new locality for one of the handsomest of our 
native plants. I met with it again further on, near Cahir. [ 
noticed Nymphea alba, Hippuris vulgaris, Ginanthe phellandrium, 
and Juncus glaucus, a long way inland for the last-mentioned 
species. 

The following morning, June 3, we left Cahir, and followed 
the right bank of the river through the beautiful demesne of Lady 
Margaret Chartreuse. Here first I met with Scrophularia aquatica, 


302 Scientific Proceedings, Royal Dublin Society. 


afterwards becoming abundant. A little below Cahir the follow- 
ing also occur :—Thalictrum flavum, Nasturtium palustre, Ginanthe 
phellandrium, C4. crocata, the latter becoming frequent soon, and 
Tussilago petasites. Near the end of the demesne I found Carex 
acuta abundant. Here, too, is a wild-looking patch of Senecio 
saracenicus, but I believe it is unquestionably an introduced plant 
in Ireland. After a few miles we approached Ardfinan, Orchis 
morio and Thalictrum flavum still accompanying us. In the 
village of Ardfinan Senebiera didyma has established itself, 
and in the stream Sparganium simplex was observed. About 
a mile lower down I met with Scirpus sylvaticus again; and all 
the way on to Clonmel Thalictrum flavum, Nasturtium palustre, 
Scrophularia aquatica, and the two (Mnanthes are frequent 
and characteristic. About three miles below Ardfinan, near 
St. Bridget’s Well, I gathered Senecio saracenicus for the second 
time, and on the opposite side of the river Humulus lupulus is, at 
any rate, thoroughly established. A little below Newcastle Sym- 
phytum officinale was first met with, and about three miles further 
on Lotus major was also observed. At Knocklofty and in Kil- 
manahan wood the timber is magnificent and well worth a visit, 
the ash-trees and a species of poplar (P. monilifera) being the 
finest I have ever seen. These are by the river, which we crossed 
here to the left bank. Since Newcastle the Suir has doubled back 
northwards in its course for several miles to the present point, 
whence it flows east through Clonmel to the sea at Waterford. 
Here many large shade-loving and aquatic plants abound; amongst 
them I gathered Carex strigosa, a very rare sedge in Ireland. I 
had found it previously, I believe, near Cahir. In the rank soil 
beneath this large timber CGinanthe crocata reached a height of 
above seven feet, and Helosciadium nodiflorum rivalled it with six 
feet of erect growth and radical leaves about three feet long in the 
largest plants. These will, I think, be recognised as extraordinary 
dimensions. Here were found also Alliaria officinalis, Epilobium 
hirsutum, Valeriana officinalis, Crepis paludosa, Dipsacus sylvestris, 
Filago germanica, and Carex sylvatica. Peucedanum ostruthium was 
noticed, too, apparently established amongst ground that had pre- 
viously formed a road. In a couple more miles we reached Clon- 
mel, where we remained for the night. 

Next morning, June 4, we kept the towpath on the left or 


Hart— On the Botany of the River Suir. Bi313) 


north side of the river till we reached Carrick, and at the same 
time the limit of tidal effects. The river had quite lost its charms. 
For many miles the Galtee, Commeragh, and Knockmealdown 
Mountains had been at one point or another conspicuously beauti- 
ful against the skyline, while the immediate banks of the river 
were in several places lovely beyond description. But we had 
turned our backs on these charms, and descended to a richer and 
uglier plain, and to a badly macadamized towpath. So that we made 
all speed to Waterford, and hurried home by an afternoon train to 
Dublin. At Clonmel Senebiera didyma, Solidago virgaurea, Carduus 
pycnocephalus, two Scrophularias, and two C#nanthes occurred. 
From Clonmel downwards sedges have almost entirely disappeared. 
Scrophularia aquatica is very abundant, and so also is Nasturtium 
palustre. With the latter I found NV. sylvestre also, a known locality 
for this plant, which is only found elsewhere in Ireland in one 
place on the Blackwater. Near Clonmel Hypericum anglicum grows, 
looking quite wild, on the river banks. It is, of course, not native 
in Ireland. From Kilsheelan bridge the proximity of the sea is 
soon felt. Cormorants begin to be plentiful, and near Carrick 
Zostera marina makes its appearance, accompanied by maritime 
sedges. 

In conclusion, I will enumerate the species which may be added 
to the lists for District 7 and District 2 of the Cybele Hibernica, 
and some others whose range has been extended :— 


District 7. District 2. 
Lycopus ewropeus, Linn. | Orchis morio, Linn. 
Myriophyllum alterniflorum, D.C. Potamogeton lucens, Linn. 
Juncus glaucus, Khrh. Eriophorum latifolium, Hoppe. 
Carex remota, Linn. Carex acuta, Linn. 
C. ovalis, Good. C. strigosa, Hud. 
C. acuta, Linn. C. paludosa, Good. 
C. pilulifera, Linn. 
C. vesicaria, Linn. 
C. riparia, Linn. 
Lycopodium clavatun, Linn. 


Equisetum maximum Linn. 


304 Scientific Proceedings, Royal Dublin Society. 


The following less common plants, though previously recorded 
from the district in which I found them, were discovered in new 


localities :-— 


Thalictrum flavum, Linn. 
Ranunculus lingua, Linn. 
Nasturtium palustre, De Cand. 
Senebiera didyma, Pers. 
Armoracia amphibia, Koch. 
Myriophyllum verticillatum, Linn. 
Ginanthe phellandriwn, Lamk. 


Senecio saracenicus, Linn. 
Lysimachia vulgaris, Linn. 
Scrophularia aquatica, Linn. 
Scirpus sylvaticus, Linn. 
Carex vesicaria, Linn. 

C. riparia, Linn. 

Bromus commutatus, Schrod. 


XXXVIT.—ON VOLATILIZATION OF ZINC FROM GERMAN- 
SILVER ALLOYS. By A. R. HASLAM. 


[Read, November 17, 1884.] 


Havine read some time ago a Paper, in which it was stated by 
the writer that in the manufacture of German silver and brass con- 
siderable loss is sustained by the zinc becoming vaporized during 
the melting and cooling of the alloy, it occurred to me that the sub- 
ject was deserving of further investigation, and accordingly the 
following somewhat interesting experiments were undertaken by 
me, first, to find the rate at which the zinc is vaporized by heat; and 
secondly, what action the other constituents, copper and nickel, exert 
on this vaporization. Three specimens of commercial German silver 
were obtained, having the following per centage composition :— 


1 | 2. | 3 
Copper, . : 53°5 50°4 56°3 
Nickel, . : | 14°3 | 17°6 11:4 
Zine, : : | 31°8 31-2 31:9 
Tron, ¢ P| trace. | 


The quantity used for experiment was in each case 2:258 grammes, 
and the following method was found both convenient and suitable 
for estimating the loss of the zine. 

The alloy was placed in a small porcelain crucible provided with 
a close-fitting lid, through which passed two tubes, likewise of por- 
celain, so that a current of dry hydrogen could be transmitted 
through it, and over the alloy. The crucible and its contents were 
then heated to bright redness in a Bunsen flame, and the alloy 
weighed from time to time, to ascertain the loss consequent on the 
evaporation of the zinc. ‘The following table gives the results :— 


Scientific Proceedings, Royal Dublin Society. 


306 


3. 


2. 
Loss per Hour | Loss per Hour 


in grammes. 


in grammes. 


058 


050 


056 


044 


050 


034 


044 
037 
029 


024 


016 


014 


274 


182 


1. 
Loss per Hour 
in grammes. 


056 


052 


"045 


038 


026 


016 


233 


Hours. 


Total loss 


It will at once be noticed, on looking at the above table, that 


ay = oe = ee = Xs © ) 


-00 grammes. 


50 
0. hours. 


CUCM se Pa 


any 


pee 
fp 


ar 
nec aA EN 


a 
a 
Leal 
FQ 
hey 
° 
o 
— 
a 
=) 
(=) 


Curves of 
German Silver. 


Curves ae the Volatilization of Zine from German Silver Alloys. 


the greatest amount of loss occurs in every case during the first 


Hastam—On the Volatilization of Zine. Bis A 


hour of experiment. After this there is a steady decrease in the 
amount of zine vaporized from the alloy. In one experiment the 
alloy was heated for twelve hours, and it was found that the loss 
sustained in the last hour only amounted to -004 grammes. 

The action of the other constituent, nickel, of the alloy is very 
striking. It will be observed that No. 2 alloy contains the most 
nickel and the least copper, and that the vaporization of the zine 
proceeds more slowly in it than in the other alloys, while No. 3 
contains the least nickel and most copper, and is dissociated much 
quicker. A. specimen of brass of the same weight containing 30°6 per 
cent. of zine when heated for the same time gave a total loss of 
"424 grammes, or nearly double that of the German silver contain- 
ing the least nickel. The curves showing graphically this action of 
the nickel are shown in the figure. 

From these carefully obtained results I am led to conclude that 
German silver appears to have much more the character of a perfect 
alloy than brass, and that the tendency of zinc to volatilize from Ger- 
man silver is determined by the quantity of nickel present in the 
alloy, the nickel increasing the affinity of the zine. Might not there- 
fore more nickel and less copper be used with advantage in the 
manuiacture of this important alloy? 


NOTE ADDED IN THE PRESS. 


[Since this Paper was read I have made some further experi- 
ments on an alloy of nickel and zinc, having as near as possible the 
composition NiZn,. On heating this alloy, it was found that in six 
hours it had lost 122 grammes, or 060 less than the German silver 
alloy containing the most nickel. It was also found impossible at 
a bright-red heat to expel all the zine from this alloy, 9 per cent. 
remaining constant, while in the case of brass, the percentage of 
zine may be reduced as low as 1 per cent. I have not found it 
possible to deprive brass entirely of its zinc by heating it in a 
porcelain tube over a combustion furnace: from °6 to 1 per cent. 
remains constant. | 


SCIEN, PROC. K.D.S.— VOL. IV. PART VI. Din: 


[3389 


XXXVIII.—NOTE ON DUST REPULSION. By GEORGE 
FRANCIS FITZGERALD, A.M., F.T.C. D. 


[ Read, June 5, 1884. ] 


Dr. Oxiver J. Lopes has pointed out that when a body is warmer 
than dusty air in its neighbourhood, the dust has a tendency not to 
settle on it. When speaking to him on the subject he did not 
seem to have been aware of Prof. O. Reynolds’ experiments on the 
motion of silk fibres suspended in air and subject to radiation,’ 
which Professor O. Reynolds explains by the absorption of the 
radiations by the silk, and the consequent polarization of the air, 
warmed by contact with the small fibres, producing an apparent 
repulsion of the fibre. Professor O. Reynolds’ theory of the 
radiometer points to the conclusion that very small bodies would 
act in dense air in the same way as the comparatively large vanes 
of a radiometer do in rare air. This application of Professor O. 
Reynolds’ theory to explain the tendency of the warmth of a body 
to prevent dust settling on it seemed very obvious, and occurred to 
me immediately I heard of the experiments of Dr. Lodge, and I 
would not have thought it worth while mentioning only that I 
found that Dr. Lodge himself did not seem to have noticed it. 


1 Phil. Trans. R. 8., 1879, part ii. On Certain Dimensional Properties of Matter in 
the Gaseous State. 


[ 380.) 


XXXIX.—ON CURRENTS OF GAS IN THE VORTEX ATOM 
THEORY OF GASES. By GEORGE FRANCIS 
FITZGERALD, A.M., F.T.C.D. 


[Read, June 5, 1884.] 


Mr. J. J. THomson, in his book on Vortex Atoms, has called parti- 
cular attention to the fact that the momentum of a vortex ring being 
proportional to its area, and its velocity through the medium get- 
ting less the greater its momentum, the velocity of hot simple vortex 
atoms is less than that of cold ones. Professor Osborne Reynolds, 
in his review in Nature, December 27th, 1883, of Mr. J. J. Thom- 
son’s book, called attention to the discrepancy that exists between 
this result and the fact that the velocity of sound is greater in hot 
than in cold gas. Now, on considering how the velocity of sound in 
a gas composed of vortex rings would be propagated, it is at once 
evident that the usual equations of motion do not apply to a system 
of atoms whose momentum is not proportional to their velocity, 
and this at once raises the question, What is the momentum of a 
current of vortex atoms? ‘The answer to this of course depends on 
what the nature of a current of gas formed of vortex atoms is sup- 
posed to be. If it be supposed to be a current of the medium car- 
rying the vortices with it, and if it be further supposed that the 
amount of medium carrying a given mass of vortices is independent 
of their size, then the momentum of the current will be, as we 
know it is, independent of the temperature of the gas. These 
assumptions, however, seem quite at variance with Mr. J. J. Thom- 
son’s investigation as to the relative velocity of hot and cold vortex 
atoms, where he assumes that each vortex atom moves, independently 
of the rest, through a medium at rest, and carries its momentum 
with it, and that the general effect is simply the superposition of 
the effects due to these independent vortices. ‘The assumption as 
to the nature of a current of gas, that is consistent with this method 
of treating the subject, is the usual assumption that a current of gas 
consists in the motions of the molecules being so polarized that 
there are a greater number of molecules moving in the direction of 
the current at any one time than in any other direction, but that 


040 Scientific Proceedings, Royal Dublin Society. 


the molecules are moving individually independently, and in the same 
manner as they do in agas at rest. For instance, if a region in 
which there were many vortex atoms were in communication with 
one in which there were only a few, the vortex atoms would diffuse 
in a current out of the former into the latter. Now the momentum 
of this current for a given number of vortex atoms transferred per 
second across unit area would depend on the momentum of each 
vortex atom, and as this momentum is not proportional to the 
velocity of the atom, and is a function of its temperature, it is 
evident that the momentum of such a current would be a function 
of its temperature. 

The whole notion that atoms are vortex rings in a medium 
raises serious difficulties as to the amount by which this medium is 
carried along by the motion of the earth, for instance, and by solid 
bodies enclosing masses of gas. Ii the earth does not carry the 
medium with it, the vortex atoms in the air must be so energetic 
as to be moving at nineteen miles a second through it, and their 
size and momentum must vary considerably from day to night, as 
they are going so much more rapidly at night than by day. 
Similarly the momentum of an enclosed mass of gas would vary 
with its temperature, if moving the enclosure only moves the en- 
closed vortices. On the other hand, if the earth does carry the 
medium with it, what withstands the centrifugal force of this 
revolving medium? Why does it not originate an enormous 
vortex? ‘This and similar difficulties seem to point to the con- 
clusion that to suppose atoms to be simple ring vortices in a 
perfect liquid can hardly be an adequate theory. There seems 
very good reason for believing that the hypothesis that the 
medium is simply a perfect liquid is hardly sufficient. It cer- 
tainly is not sufficient to explain luminous and electrical and 
magnetic phenomena, to suppose the ether to be simply a perfect 
liquid at rest ; and though it is too much to say that it will not 
ultimately be found a sufficient foundation for a theory of matter 
and material phenomena, at present, at least, there seems very 
little prospect of anybody’s inventing how it ought to be moving, 
in order to have the known properties of the ether; and even 
the ingenious attempt to explain matter as due to simple ring 
vortices in it seems too simple to be adequate. 


Pe sae | 


XL.—ON A METHOD OF STUDYING TRANSIENT CURRENTS 
BY MEANS OF AN ELECTRODYNAMOMETER. By 
GEORGE FRANCIS FITZGERALD, A.M., F.T.C.D. 


[Read June 7, 1884. ] 


WHEN a current of short duration, compared with the period of 
free vibration of a galvanometer needle, is passed through the 
galvanometer, the total quantity of the current is proportional to 
the sine of half the angle of swing of the needle. The swing pro- 
duced is independent of the distribution of intensity of the current 
during its passage. 

Now, i a similar transient current be passed through an electro- 
dynamometer, we have the following equation for the motion of the 
suspended coil while a current C is passing :— 


d’0 : 
Te: ap = HO 
where J is the moment of eS of the coil and & a constant. 
Hence do _ i C* dt 
dt\, 


gives the angular velocity with which the needle begins to swing. 
If the suspension be bifilar during its free swing the motion is 
given by the equation : 
ao : 

JE dE. =—-k. sin 0, 
where / is a‘constant depending on the method of suspension, &c. 
Hence, for the maximum swing, 

ae 

ah =v T . Sn 40. 


Comparing this with the other value, we obtain 


{[C’dt = a . sin £0. 


Now the value of { C’dt ae upon how the current varies 
during its period of transit, and if we can form any hypothesis as 


342 Scientific Proceedings, Ruyal Dublin Society. 


to the law of its variation, we can calculate the period it took to 
pass, and its maximum electromotive force by comparing this re- 
sult with that given by an ordinary balistic galvanometer. 

For instance, the secondary current at any time in Ruhmkorff's 
coil may, to a first approximation at least, be represented by an 
equation 


; t 
C = G, s1n 7 T 
where CO, is the maximum current, and 7’ the whole time of flow. 
The total current as given by the balistic galvanometer is 


Te ) 
Q=| Cat = al sin w pdt= = 


OT = 17Q. 


Tw 


The quantity given by the electrodynamometer is 
i 
S=[C'dt= a | fee dt =1C/T; 
0 L jj 
mw Q 48 


therefore I= 3g and O, = aa 


It is thus,easy to see that the comparison of these observations 
would give a great deal of information about transient currents. 


(843. J 


XLI—ON A NON-SPARKING DYNAMO. By GEORGE 
FRANCIS FITZGERALD, A.M., F.T.C.D. 


[Read, June 9, 1884.] 


Wuat are called unipolar dynamos have no sudden change in the 
nature of the sliding contact, which is essential in all dynamos, and 
are consequently non-sparking. The arrangement I am about to 
describe is somewhat different, and is an application to a dynamo 
of the principle that Maxwell applied to Sir William Thomson’s 
electric doubler (Maxwell’s Electricity and Magnetism, vol. 1., 
p. 298, s. 218) in order to prevent sparks in it, and which he 
likened to the regenerator in a heat engine. 

Consider a series of coils arranged to rotate in a magnetic field 
as a gramme ring, but with their wires unconnected with one 
another, each coil being connected with a separate commutator 
and pair of brushes, and half the brushes being connected with one 
electrode, and the other half with the other. In this case the cur- 
rent would in general go through a number of the coils in parallel 
circuit. Now it is evident that by a suitable arrangement of the 
magnetic field and of the positions of the brushes on the commuta- 
tor, it could be arranged that the break of contact of the brushes 
and commutator should take place when the current in the coil was 
zero. This is evident, because if the brushes made contact through- 
out a whole revolution, as in an alternating current dynamo, the 
current would be reversed every half revolution; and if the instant 
of reversal were the instant of break of contact, this would happen 
when no current was passing in the coils. It is not possible to 
arrange this unless there are at least two parallel coils carrying 
the current, as otherwise the whole current would be fluctuating, 
and might as well be alternating. With a number of coils parallel, 
it would evidently be quite possible to arrange that the time of 
break of contact of each pair of brushes and its commutator should 
occur when no current was running in the corresponding coil. One 
way of doing this would be, as in Maxwell’s electric doubler, to 
arrange a subsidiary magnet system to alter the magnetic field 


344 ‘Scientific Proceedings, Royal Dublin Society. 


until the desired effect was produced. In any arrangement, with a 
number of coils in parallel circuit, it would be necessary to be par- 
ticular as to the arrangement of the magnetic field, for fear of the 
currents being reversed in some of the coils. This would evidently 
waste a good deal of energy in heating the coils. In the proposed 
arrangement the energy of self-induction usually wasted in sparks 
would be spent in keeping the current running in the line, and 
there is reason to expect that such a dynamo would not exhibit the 
apparent increase of resistance with speed pointed out by Messrs. 
Ayrton and Perry. 


XLII.—ON PHOTOMETERS MADE OF SOLID PARAFFIN, OR 
OTHER TRANSLUCENT SUBSTANCE. By J. JOLY, 
B.E., Assistant to the Professor of Civil Engineering, 
University of Dublin. 


[Read, December 15, 1884. ] 


WueEn light enters a translucent body, such as paraffin, milk-glass, 
common opal, &c., it behaves as if scattered within the substance 
by numerous reflections—as if such bodies were not homogeneous, 
but consisted of particles differing in physical properties, in so far 
that some of them are opaque, others transparent, or as if some 
partial molecular symmetry led to the existence of planes of supe- 
rior density within the substance. Such a substance as milk-glass 
would be an example of the first class of bodies ; paraffin possibly 
of the second, or partly of both. 

If now a prism be cut from a translucent body, and so exposed 
to a source of light that one only of its faces be illuminated, the 
light diffused through the substance and reflected out through the 
unilluminated faces of the prism gives it an appearance as if lighted 
up internally. The effect, in fact, is as if the prism itself was a 
source of light. Two such prisms laid together on smooth faces, 
and receiving light from separate sources (placed so as to be at 
opposite sides of the plane of division), appear as if each was 
emitting light proportional in intensity to the source of its supply. 
The double prism has the appearance of two luminous bodies laid 
side by side. When, however, the supply to each prism is brought 
to equality, they appear as if emitting equal quantities of light. 
In fact, it is hard to detect any longer that to prisms are being 
observed, so completely does all trace of the plane of division dis- 
appear. 

The photometer I wish to bring to your notice consists of two 
prisms of paraffin, parallelepipeds in form, each about 2¥”x 1"x ¥, 
sharply cut to the same dimensions, and laid together in their 23” 
x 1” paces. In this position they are retained by two brass rings, 
~ such as are u. 2d for mounting objects for the microscope, melted 
on at each end. 


The two sources of hight to be compared are arranged at oppo- 
SCIEN. PROC. R.D.S.—VOL. IV, PT. VII. 2H 


346 Scientific Proceedings, Royal Dublin Society. 


site sides of the plane of division, and the combined prisms shifted 
till the intensity of the light received at opposite sides of the 
. divisional plane is brought to equality—till, in fact, the prisms lie 
in an equally illuminated field. In this position the discontinuous 
appearance of the prisms vanishes, and they look like one con- 
tinuous block of paraffin. ‘While, however, ‘this complete dis- 
appearance of the divisional line takes place when the sources of 
light are emitting rays of like colour, in general comparison is not 
between such, and a certain amount of judgment is required to 
determine when the two differently tinted luminous bodies are 
emitting equal quantities of light. This objection applies to all 
photometers of visual comparison: in this form the difficulty is 
much lessened by watching solely for the least conspicuous ap- 
pearance of the line as the prisms are shifted. ‘Tinted glasses 
to cut off these rays not common to both sources of light can, 
of course, be used. 

It is found that more sensitive measurements are obtained 
from this form of photometer than from Bunsen’s; the operation 
of adjustment also is less fatiguing, and is more rapidly effected. 
The sensitiveness of the arrangement is still further increased by 
interposing a silver leaf between the prisms, thus stopping all 
passage of light from one prism to the other. The addition of a 
lens for observing the divisional line adds to the facility and ease 
of adjusting. In this form, suitably mounted and protected from 
accidental sources of light, it will be found that the least move- 
ment from its position of equilibrium is noticeable. This ex- 
treme sensitiveness and ease of working is due to the very close 
juxtaposition of the luminous surfaces undergoing comparison. 
In Bunsen’s photometer the surfaces compared are seen at some 
inches removed from each other. 

Experiments have been made with alabaster, and with a highly 
translucent marble known as Mexican agate. These substances, 
however, proved inferior to paraffin. Good results would probably 
be obtained from milk-glass. 

It is to be noted that if the prisms be not quite similar in 
translucency (they should be cut from the same piece of paraffin), 
it will be necessary to take two readings, with the faces of the 
combined prisms reversed in position respecting the lights, the 
mean of the two readings being taken as correct. 


Eon | 


XLII.—NOTES ON THE APATITE OF BUCKINGHAM, 
OTTAWA COUNTY. By G. H. KINAHAN, M.R.I.A. 


[Read, December 15, 1884.] 


THE apatite appears to be diffused very like galenite in limestone. 
It occurs in regular lodes, that is, veins with both foot and hang- 
ing walls; in irregular veins, that 1s, having only one wall; in 
string veins running irregularly through the rocks; as “lay in lay”’ 
on in veins between the stratification; in bunches; and I suspect 
in pipe veins: of the last, however, I am not quite certain. 

According to the miners, it is always associated with a meta- 
morphosed basic igneous rock, that the Canadians call ‘“ Pyroxene 
rock”’ [but that I would class among Macculloch’s ‘ Hornblende 
rocks,” having more amphibole in them than diallage], and 
quartzites. The “ Pyroxene rock” seems always to be present, 
and in general the quartzite, but not always. 

What I saw of the apatite reminded me very much of the 
limestones and dolomytes that occur in the Irish Cambro-Silurians 
associated with igneous rocks [eurites (basic felstones) and gabbro ], 
as these Cambro-Silurian limestones and dolomytes, or their petro- 
logical equivalents, ophytes, steatytes, and such like, occur tangled 
up with these igneous rocks, usually being more or less in bunches 
or lenticular masses, and sending string veins into the igneous 
rocks, or occurring as detached pieces or concretions in them, 
while nearly always there are also quartzites associated with them. 
Where our rocks are greatly metamorphosed, as in West Galway 
and other places, the eurites and gabbro have become rocks similar 
to those in the Buckingham township. 

It has therefore occurred to me that it is possible, if not pro- 
bable, that the apatite has replaced limestone or one of the allied 
rocks by chemical change or methylosis, as called by Dr. W. King, 
of Galway. 

In favour of such a supposition, we find in the large bunches 
of apatite portions that merge into pure limestone, while in other 
places the rock will be in part apatite and in part limestone; also 


the bunches and irregular string veins remind one very much of 
2H 2 


348 Scientific Proceedings, Royal Dublin Society. 


their limestone equivalents in the Irish Cambro-Silurian eurites ; 
while the “lay and lay” are like the “shells of limestone”’ that 
are not uncommon in the county Donegal Cambro-Silurians—an 
apatite vein or a limestone vein with only one wall ‘‘makes” exactly 
similar. I could not satisfactorily find out if, in any place in the 
regular lodes, the apatite changed entirely into calcite | I was too 
weak and giddy after my recent illness to go down all the different 
shafts and deep workings]; but in one of the lodes which I saw 
under ground there was evidently calcite in places associated with 
the apatite. 

When the apatite of the bunches is associated with limestone, 
the apatite in part is in crystals, from one inch or less to a foot or 
more in diameter. The largest crystal that has been got was 
found in the Emerald mine, just before I visited it, and weighed 
800 Ibs. ; other accessories, such as crystals of black and white 
mica, amphibole, &c., &c., occur more frequently in the bunches 
than in the other accumulations of apatite. 

In the Chelsea district (the vale of the Gatineau), nearer 
Ottawa, where the rocks are not as highly metamorphosed as in 
the Vale of the Du Lievre (Buckingham township), there are 
eurites and gabbros associated with limestones and dolomytes; but 
I could not find apatite, unless one specimen (which as yet I have 
not been able to get analysed) should turn out to be it: I suspect, 
however, it is not so. 


NOTE ADDED IN THE PRESS. 


On examination, the rock in question was found to contain a small 
percentage of apatite. 


e349) 7] 


XLIV.—CANADIAN ARCHAIAN, OR PRE-CAMBRIAN ROCKS: 
WITH A COMPARISON WITH SOME OF THE IRISH 
METAMORPHIC ROCKS. By G. HENRY KINAHAN, 
M.R.I.A., &c. 


[Read, December 15, 1884. ] 


Tis Paper can only give a more or less general sketch of the 
subject in hand, as the time I had to spend in Canada was very 
limited; but at the same time the opportunities for examining the 
rocks were considerable.. I would specially mention that the ob- 
servations made, and the conclusions come to, were all personal; 
as, prior to visiting the different places and drawing my own 
conclusions, I was unacquainted with the opinions of the various 
writers on the subject, having read none of the literature connected 
therewith, except Logan’s Report many years ago. I must, how- 
ever, allow that, as the readers of my Papers in connexion with 
the supposed Archeean rocks in Ireland are aware, I have no faith 
in merely lithological characters, or in the boundaries and divisions 
founded solely on them: this circumstance may be supposed in 
part to have more or less prejudiced my judgment. But as my 
matured conclusions agree, as I find, in a great measure with 
those of Logan and Selwyn, they may perhaps be worthy of 
record. The title of this Paper is, perhaps, too presumptuous, as 
more properly it is a review of the Irish highly metamorphic rocks, 
and a comparison between them and some of the Canadian 
Archean or Pre-Cambrian rocks. As introductory to the subject 
of the Paper, I beg to submit some observations on foliation, or 
the structure induced by metamorphism; and some other pheno- 
mena connected therewith, the examples being nearly entirely 
confined to Ireland, where this action has been more minutely 
studied. 

Students of petrology and lithology seem now in general to 
believe in three classes of metamorphism, namely, Regional and 


300 Scientific Proceedings, Royal Dublin Society. 


Contact, for which I have proposed respectively the terms Ieta- 
pepsis and Paroptesis (see “Geology of Ireland,” p. 175), and 
Chemical change, called by King, of Galway, Methylosis, while for 
a molecular change the American authorities use the term Para- 
morphosis. At the present time it 1s not intended to refer to the 
rocks of the latter classes, as these preliminary remarks refer 
specially to the others. 

Paroptesis, or Contact metamorphism, must necessarily occur 
at a different time from Metapepsis or Regional metamorphism, in 
one and the same area; and the former may have taken place be- 
fore or after the latter; or possibly there may have been two or 
more periods during which one or other of the actions may have 
been in foree—thus, for instance, in a region there may have been 
first, in places, Paroptesis, which was succeeded by Metapepsis; 
while subsequently, in places, there was a newer Paroptesic action, 
or newer Metapepsis. The present state of metamorphism of some 
of these older Canadian rocks would seem to suggest that they had 
been subjected to a succession of alterations due to both of these 
kinds of metamorphism. 

The 8S. E. of Ireland is an instructive area; as on both sides 
of the granite protrusion of the Leinster range there are bands 
of Paroptesic rocks. Those to the westward of the granite ridge 
have not been again altered (except some hereafter to be men- 
tioned), while those eastward of the ridge have all experienced 
a second change, due to Metapepsis, which invades nearly all the 
Lower Palzeozoic rocks of these portions of the counties of Dublin, 
Wicklow, and Wexford. 

Thus, as a general rule, to the westward of the granite ridge 
there is a band of “ baked” rocks, due to Paroptesis; while east- 
ward of the ridge there is a band of typical gneiss and schist [ due, 
first, to Paroptesis, and subsequently to Metapepsis], outside which 
are more or less metamorphic rocks [due to the subsequent meta- 
pepsis]. The metapepsic action seems to have been most intense 
in certain oblique westerly and easterly lines, so that if we traverse 
the region from north to south we will alternately pass over meta- 
morphic and sub-metamorphic rocks; that is if we ignore a subse- 
quent action now to be mentioned. 

In this region, besides the intrusions of the normal Leinster 
granite (Cambro-Silurian age ?), there were also newer intrusions 


Kinanan—On Canadian, Archean, and Pre-Cambrian Rocks. 351 


(Devonio-Silurian'), which were accompanied by Paroptesis; so 
that in connexion with them we find the rocks more altered, the 
“baked” rocks in the band to the westward of the ridge having 
been changed into schists; while in places to the eastward the 
metamorphism has been intensified. 

A fact which seems to be important is, that in connexion with 
the interstratified igneous Cambro-Silurian rocks there are the 
granitic roots (/accoliths of Gilbert), and in connexion with these, 
from the appearance of the adjacent rocks, there seems to have 
been Paroptesis; this, however, can only be conjectured, as the 
more recent Metapepsis has more or less obliterated it. Still, how- 
ever, it should be kept in mind, as it shows how many stages of 
metamorphism rocks may have gone through. 

» There is also in this region a peculiarity still to be mentioned 
in the metamorphism. Years ago, in reference to the rocks of 
Dublin and Wicklow, Jukes pointed out that the younger, or 
Cambro-Silurian rocks were more altered than the older, or Cam- 
brians. This, if I remember rightly, he suggested, was more 
apparent than real, as only the Cambro-Silurian in contact are 
exposed. But down 8. E., in the county of Wexford, away from 
the granite ridge, the same thing occurs; as, nearly always, along 
the boundary between the Cambrians and Cambro-Silurians the 
latter are more altered than the former.’ In the county Wicklow, 
to the north-west and westward of Rathdrum, there are rocks that 
Jukes put in the altered Cambro-Silurians, while Wyley would 
put them in the Cambrians, as has been mentioned elsewhere. I 
believe Wyley is right, they being intensely altered Cambrians, 
Jukes including them among the Cambro-Silurians on account of 
his having proved elsewhere that the latter were much more 
altered than the former. This confusion of the Cambro-Silurian 
and Cambrian will be referred to again. 


1 In the Old World the terms Lower Silurian, Upper Silurian, Devonian, and 
Lower Old Red Sandstone, are very much connected together. Selwyn, however, in 
his writings, seems to have adopted for the older rocks Phillips’ term, Cambro-Silurian; 
and for the newer, Devonio-Silurian: as these are very expressive they will be used 
in this Paper. 

2 In connexion with this phenomenon it may be mentioned that, in the Belvoir 
section (Cambro-Silurian), county Clare, there are fossiliferous and jasperized rocks 
alternating. The reason of the different degrees of action in the county Wexford 
rocks I have attempted to explain in the ‘* Geological Survey Memoirs,” 


352 Proceedings of the Royal Dublin Society. 


The Cambrians of 8S. E. Wexford show some peculiar phases 
in metamorphism. Go northward, along the coast from Carnsore, 
by Carne to Greenore, and you meet, first, oligoclasic porphyritic 
granite; then oligoclasic coarse gneissic granite, which merges 
through gneiss into schist, the gradations from the gneissic granite 
to the gneiss being apparently abrupt; the section, however, is not 
very well exposed. If, however, you go a short distance west- 
ward, you find on the Saltee Island fine orthoclasic gneissic granite, 
in which are a few subordinate hornblendytes (hornblende-schist) ; 
while on the main land at Forlorn Point (Kilmore Pier), there are 
on the south shore-line hornblendytes, which by alternation of beds 
graduate into a considerable thickness of fine orthoclasic granitic 
gneiss, the latter to the northward having a hard boundary, out- 
side of which are hornblendytes and other schists. This sudden 
change in lithological characters will be hereafter referred to when 
speaking of the Canadian rocks. 

In the Mourne Mountains district, county Down, there are 
two distinct granite intrusions (Post-Cambro-Silurian (?) and Post- 
Carboniferous) (?), the latter, however, possibly Carboniferous. The 
Cambro-Silurian rocks of the area are altered (sub-metamorphic) 
by metapepsis, probably an adjunct of the genesis of the older 
granite; but subsequently, along the boundary of this granite, a 
newer action was in force, which developed a foliated structure in 
the adjoining granite, and altered a band of the sub-metamorphic 
rocks. This, as first pointed out by W. A. Traill, must have 
taken place subsequent to the intrusion of the granite, as the 
veins from it into the sub-metamorphic rocks are altered in a 
similar ratio to what has taken place in them. The rocks now 
occur in the following order :— 


Granite, Tl ae Ags : 

nae : 1e original granite intrusion. 
Gneissic granite, 
Hard boundary. 
Gneiss band “te : 
ce ; The original sub-metamorphic rocks. 
Schist, 


The newer granite (Post-Carboniferous ?) has not to any great 
extent altered the rocks adjoining it; but at the same time more 
or less signs of Paroptesis are apparent. 


Kinanan—On Canadian, Archean, and Pre-Cambrian Rocks. 353 


In the counties Galway and Mayo different phases of meta- 
morphism can be studied. At first everything may appear to be 
under general law, but when details are entered into, here, as 
elsewhere, there are peculiarities hard to be explained. 

Go northward from the ground westward of Galway town to 
Oughterard, across the strike of the rocks, and you first meet 
porphyritic oligoclasic granite, which changes nearly impercep- 
tibly into oligoclasic porphyritic gneissic granite; while the latter 
graduates through gneiss into schist, and still further north, in 
the county Mayo, into unaltered Cambro-Silurians. Although in 
general the gneissic granite graduates into gneiss, yet in some 
places there is a hard boundary between them. 

Go westward along the strike of the rocks and the change is 
not so gradual, as in places there are sudden jumps from granitic 
to schistose rocks; while in the latter you find outliers, sometimes 
having a nucleus of porphyritic oligoclasic granite, but more 
often porphyritic gneissic granite, which are more or less suddenly 
replaced by schist. 

Tf, however, we go southward, there is a complete change in 
the character of the metamorphism ;.as in places along Galway 
Bay, margining the porphyritic oligoclasic granite, there are 
eneissic granites, usually orthoclasic and fine-grained, but having 
in them coarse-grained and oligoclasic beds; also to the 8. H., at 
Galway town, there is a completely different group of rocks; as 
suddenly, adjoining the granite, and in a few small patches on it, 
or entangled in it, are schists principally hornblendytes. ‘This 
small area of schists, apparently in such close proximity to the 
mass of the oligoclasic porphyritic granite seems very peculiar ; 
this might, however, be explained by referring to phenomena that 
can be studied farther westward, near Roundstone and Slyne 
Head. As, however, it would take some time to do so, and the sub- 
ject is in part foreign to the present inquiry, it seems sufficient to 
notice it without going into further particulars. 

In the county Galway the coarse oligoclasic gneissic granites 
are evidently, especially across the strike, a portion of the series of 
gradation from metamorphic granite to schist and unaltered rocks ; 
but in the Castlebar district, county Mayo, as first pointed out by 
Symes; there are undoubted intrusive masses or courses of a simi- 
lar rock. These Mayo rocks seem interesting, as in the Canadian 


304 Scientific Proceedings, Royal Dublin Society. 


Laurentians there are intrusive masses of coarse gneissic granite 
Labradorians or Norians of the Canadian geologist. 

From the published writings in connexion with the oligoclasic gra- 
nite and associated metamorphic rocks of the county Donegal, it is 
evident that the sequences are very similar to those in the counties 
Galway and Wexford, there being a mass of granite that graduates 
in some directions through coarse oligoclasic gneiss into schists; 
while in other places, similar to those on the south of the Galway 
mass, it is margined by fine orthoclasic gneissic granites. At the 
same time, however, as a general rule, the boundary between the 
more intensely altered rocks and the sub-metamorphic rocks seems 
to be more marked than usual. This, however, from the peculiar 
faults and dislocations of the rocks, should be expected. 

It is unnecessary now to dwell longer on the Irish localities, 
more especially as hereafter some of them will have to be men- 
tioned in detail; but I would again call attention to certain traits 
in metamorphism. Years ago I pointed out that in the West 
Galway and Mayo district, the planes of foliation of rocks in the 
second stage of metamorphism’ followed the planes of the more 
conspicuous structures in the original rocks, whether these be due 
to lamination, cleavage, oblique lamination, spheroidal structure, 
concretionary structure, or any of the peculiar structures found in 
calcareous rocks; while in the typical granitoid gneiss all the ori- 
ginal structures, except the planes of stratification, are nearly 
always obliterated, the new foliation being vertical, or nearly so. 
Asin many places there is a hard boundary to the granitoid gneiss, 
it may be suggested that it is possible that its coarse foliation is 
due to a newer and subsequent metapepsis, which extended only to 
certain limits, intensifying the foliation inside these, while it did 
not affect the rocks outside them. We may now proceed to the 
metamorphic rocks of Canada. 

Why is metamorphism in Canada so much restricted to the 
older or Archean rocks, when, in our little island, we have meta- 
morphosed Cambrian, Cambro-Silurians, Devono-Silurians and 
Lias ? 

A striking feature of the Canadian Laurentians is the massive 
coarseness of the foliation in some of the gneiss. This, as just 


1 See ‘‘ Geology of Iveland,”’ chapter x. 


Kinanan—On Canadian Archean, and Pre-Cambrian Rocks. 855 


mentioned, appears to me to be due, not to excessive metamor- 
phism at one and the same time, but to the rocks having under- 
gone two, three, or even more, successive, but independent invasions 
of metamorphism, which developed instead of obliterating the la- 
minz due to the earlier metamorphisms. Excessive metamorphic 
action in a portion of an area will change the rocks into granite 
(“Geology of Ireland,’ chap. x., p. 175), but if a milder metamor- 
phism invades rocks at different successive times, the plates or 
lamin should be more and more developed. This can be seen on 
a small scale in various places in Ireland, the best, perhaps, being 
the gneiss developed adjoining the already-mentioned “Slieve 
Croab granite,” county Down, Mourne Mountain district (‘ Geol. 
of Ireland,” chap. xi., p. 192). In general, in the Irish localities, 
the metamorphism seems to be due to metapepsis succeeding parop- 
tesis, or in other places to paroptesis coming after metapepsis; 
while in some places one period of metapeptic action appears to 
have followed a former one; and we can well imagine that very 
old rocks may have been subjected at various times to metapepsis, 
with, in more limited areas, paroptesis. In the west of county 
Galway (Connemara), to the north-westward of the tract of meta- 
morphic granite, there are the previously-mentioned outliers, in 
part granite and in part granitoid gneiss. These, I would suggest, 
may probably be patches which at first were altered by paroptesis, 
while subsequently, when metapepsis invaded the country, they 
became granitoid-gneiss, while the adjoining rocks were changed 
into rocks of the “ schist series.’ Sucha supposition would account 
for there not beimg the ordinary gradation from the granitoid 
oneiss through the “ gneiss series” into the “ schist series.” 

The coarse foliation can be well seen and studied in the gneis- 
sic granite called Labradorians by the Canadian geologists, and 
marked “La” on Selwyn’s new map. This rock has no exact 
representative among the Irish rocks. The rocks nearest in struc- 
ture are, perhaps, the gneissic granite ones of the barony of Moy- 
cullen, county Galway, which are evidently of metamorphic origin, 
and probably of Cambro-Silurian age; the gneissic-granite pro- 
trusions and courses in the Castlebar district, county Mayo, which 
evidently came up originally as intrusions through the associated 
Cambro-Silurian rocks; and the metamorphic gneissic granite of the 
Erris district, also in the county Mayo. There are also in the county 


306 Scientific Proceedings, Royal Dublin Society. 


Donegal some rocks in the Glen Lough district nearly allied to 
those just mentioned, but not, however, as coarsely foliated. As 
these Canadian rocks occur as intrusions, the rocks of the Castlebar 
district are more allied to them than the others.! 

It may also be pointed out that some of the varieties of granite 
are remarkable for their massive crystallization, more especially the 
pegmatites. This, among others, is very conspicuous in the white 
mica pegmatic of the Vale of the Du Lievre, the felspar usually 
being in considerable masses, while the white mica can be got in 
plates over nine inches square. The granites of the pegmatic 
group are called Endogenous by Sterry Hunt, and he suggests 
that the minerals crystallize out of solution. Such a supposition 
can easily be understood when pegmatite is found in small masses 
or lenticular veins; but it is not so easily conceived when we have 
to treat of considerable tracts. At the same time it is perfectly 
possible that in a great thickness of rocks there may have been 
vast vug's filled with mineral solutions, out of which the minerals 
of the pegmatites crystallized. From what I have seen in Ireland, 
T would suggest that this massive crystallization may not be due to 
subsequent metamorphic action. In the Aughowle district, county 
Wicklow, there is a pegmatite locally called “ Bastard granite,” 
while a variety of it is the ‘“‘ Plumose granite” of Jukes: this is 
somewhat like the Canadian pegmatites, although not as coarsely 
crystalline: it is evidently newer than the normal granite of the 
Leinster ‘type, and, consequently, ought to be younger than the 
time of the Regional metamorphism. If this is the case, the pre- 
sent structure is probably the original one, from which we may 
suggest that the Canadian rocks are also in their original form ; 
but, at the same time, as they are so much older they may have 
been further developed by metamorphic action. 

In the province of Ontario and the neighbouring portion of the 
province of Quebec, the Archean rocks are divided into Huronians 
and Laurentians. Selwyn has pointed out that such divisions seem 
to be more lithological than geological ; while, as far as I can learn, 
Logan has not stated that he had found any proofs of their being 
geological groups. On the other hand, however, Dawson (Sir J. 


1 Mixed up with the other were eruption rocks, bat the latter were portions uf the 
“ifferent groups. 


Kinanan—On Canadian Archean, and Pre-Cambrian Rocks. 357 


William), Sterry Hunt, and others, seem to insist that they are 
not only lithological but also geological groups. 

A rock that seems to be considered a typical Ontario Lauren- 
tian is a pinkish or flesh-coloured fine-grained gneiss, hand speci- 
mens of which are undistinguishable from some of the fine gneissic 
rocks of the Cambrians of south-east Wexford (Saltees and For- 
lorn) ; the Cambro-Silurians of the counties Wexford and Wicklow ; 
the Cambro-Silurians, county Galway; the Cambrians (?) of Hrris, 
county Mayo; and the Cambro-Silurians, or Cambrians (?) of county 
Donegal. Some of these metamorphic rocks—as for instance those 
of Forlorn Point—were evidently at first felspathic, and probably 
tuffose stratified rocks; this was probably the case also in many 
places where similar gneiss occurs in the counties Galway, Mayo, and 
Donegal; but there are also in those places and in the county Wick- 
low similar gneisses which evidently were originally intrusions of 
felstone or felsite. In the high ground called Chelsea Mountains, 
Vale of the Gatineau, Ottawa county, there is a granitoid gneiss 

very like some of those of Galway, Mayo, and Donegal ; that is, a 
rock intermediate in structure between the typical gneiss of Ontario 
and the gneissic granite of Chicoutimi, Montcalm, &c., province of 
Quebec—three different rocks, all somewhat similar in constituents, 
but having been subjected to different degrees of metamorphic 
action. 

In connexion with the Chelsea district may be mentioned the 
schistose rocks that occur in the lower ground nearer Chelsea. 
Associated with these are some peculiar calcareous rocks that are 
identical with some of the rocks of the ‘“‘ Ophiolyte and Dolomyte 
series” of the Twelve Pins or Connemara district, county Galway 
(“Geology of Ireland,” chap. i., p. 21). These rocks of Conne- 
mara have been suggested by King of Galway, to be of Cam- 
brian age, and my examination of the country goes to confirm 
that opinion. ' 

It is necessary before we proceed further to mention some pecu- 
liarities in connexion with certain Irish calcareous rocks. There 
are, associated with the Lower Carboniferous sandstone of Clare, 


1 These rocks, although undoubtedly some of the very oldest in the county Galway, 
have not been included in the so-called Archean rocks; those called Laurentians 
being evidently of newer age, which has been proved by their fossils to be of Cambro- 
Silurian age, and have been so classified. 


008 Scientific Proceedings, Royal Dublin Society. 


the Devonio-Silurians of Galway and Mayo, and the Cambro- 
Silurians and Cambrians of Donegal, Sligo, Mayo, Galway, Water- 
ford, Wexford, and Wicklow, calcareous rocks which are more 
or less intimately connected with basic eruptive rocks, and which 
appear to me to be in some way the result of vulcanicity (“ Geol. 
of Ireland,” chap. xii., p. 194). In the township of Buckingham, 
and elsewhere in Ottawa county, there are apatites that make 
very like the above-mentioned Irish Cambro-Silurian and Cam- 
brian limestones, they being associated and entangled with basic 
eruptive rocks—and, perhaps, it may be allowable to suggest, that 
in some way not as yet explained the carbonate is replaced by 
the phosphate of lime by methylosism—a somewhat allied case 
being the change of pyroxene into amphibole by some unknown 
paramorphosie action. 

The rocks which par excellence are called Laurentians belong 
to the lithological groups for which i have suggested the names 
“‘ Gneissic Granite” or “ Granitoid Gneiss”’ and “ Gneiss Series” ; 
while the Huronian rocks par excellence belong to the groups called 
“ Schist Series” and “Submetamorphic rocks.”? 

To these general classifications, however, there are exceptions; 
because, as in the Ottawa country, there are found in the districts, 
at the present time mapped as Laurentian,’ more or less extensive 
tracts of schistose rocks; while, on the other hand, in the Huronian 
tracts there are some gneiss. ‘This is similar to what occurs in the 
Old Country, as rarely will you find rocks of the ‘“‘ Gneiss Series,” 
or even of the “ Gneissic Granite,” in which subordinate schistose 
rocks do not occur; while in the ‘“‘Schist Series” there are always 
in places gneissoid rocks, and even in places among the “submeta- 
morphie rocks.” As already mentioned, the Laurentians and 
Huronians are undoubtedly lithological groups; but are they also 
petrological, that is, geological groups? This we have now to 
consider. 

In the province of Ontario there are numerous junctions of the 


1 These different groups are fully explained in chapter x., page 177, of the ‘‘ Geo- 
logy of Ireland.”’ 

? Selwyn specially mentions that the present boundaries and mapping are only pro- 
visional, and that hereafter many tracts of Huronian rocks will probably be found in the 
areas at present mapped as Laurentian. 


Kuananan—On Canadian Archean, and Pre-Cambrian Rocks. 359 


Huronian and Laurentian rocks, those that have been most studied 
being in the neighbourhood of the Canadian Pacific Railway, be- 
tween Port Arthur, on Lake Superior, and Winnipeg. Of these, 
that to which greatest attention has been directed is the junction 
at the rapids from the Lake of the Wood close to the settlement 
of the Rat Portage. ‘This junction is very well exposed at the 
rapids, and in other places, and is stated by Sir W. J. Dawson and 
others to be a “ Fault boundary.”’ Such a statement cannot be 
lightly passed over, especially by an Irish geologist, when he re- 
members the boundary between the Cambrians and Cambro-Si- 
lurians in south-east Ireland. These boundaries are so intricate in 
different places in the county Wicklow, especially in the neighbour- 
hood of the Carrick Mountain and Glenealy, and in the county 
Wexford, at Poulshone and Barrow, that it required a man of special 
powers of observation, such as Jukes, to be able to point out the 
unconformability of the two groups. As, from the light supplied 
by him, I have been able to satisfy myself that such intricate un- 
conformabilities may occur, I would be rash in stating that very 
similar unconformabilities may not occur in Ontario; yet, at the 
same time, I may be allowed to make suggestions, or, in the pre- 
sent case, to state that I see no reasons for supposing that there 
is necessarily an unconformability between the Laurentians and 
Huronians. First, in no place that I could hear of, in Ontario or 
Quebec, are the Huronian rocks found resting on the upturned 
edges of the Laurentians, while all the junctions seem to be such 
as what we should naturally expect to find at the meeting of two 
distinct lithological groups. This question, however, has got into 
a tangle, as it must be allowed that in Kurope, at the present time, 
our geological maps should more properly be called lithological, 
as the major portions of the divisions marked on them are litholo- 
gical and not geological divisions. ‘This is specially the case with 
the Cainozoic and Mesozoic, as the different groups in them are 
merely lithological groups; but it is not so much the case in the 
older (Paleozoic), as in it the “ formations” seem in a great mea- 
sure to be geological groups; but the sub-divisions are not so. 
Take, for instance, the sub-divisions of the English Devonio-Silu- 
rians and those of the Cambro-Silurians, and look for them in the 
same order in either Ireland or Scotland, and the result will be 
that they are found to be mixed up confusedly. The undue pro- 


360 Scientific Proceedings, Royal Dublin Society. 


minence given to lithology in modern Geology seems to me to be 
a most important consideration in the present inquiry; as what 
has to be proved is not that the Canadian Laurentians and 
Huronians are different lithological groups, but that they are 
different stratigraphical groups. The former is a plain fact; but 
I know of no positive proof that has been brought forward in 
favour of the latter. 

The mistakes that may occur by substituting lithology for 
stratigraphical and paleontological geology, can be illustrated by 
facts observed in Ireland. For the uppermost groups of the Irish 
Cambro-Silurians, I have suggested the name “ Slate Series,” as, 
in general, they consist of a great thickness of argillaceous rocks, 
and in them are found all the principal veins that have been 
worked for roofing-slate; while for the lowest group of the Cam- 
bro-Silurians I have proposed the name “ Black Shale Series,” it 
also consisting in a great measure of argillaceous rocks. In the 
north of the county Wexford, a few miles N.H. of Carnew, in the 
“Slate Series,” a great thickness of grit comes in; while in the 
Erriff Valley, county Mayo, a great thickness of nearly similar grit 
makes its appearance in the rocks of the “ Black Shale Series.” 
Now if the rocks of these two distinct areas were subjected to an 
equal amount of metamorphic action, we should have two groups 
stratigraphically very distinct, but lithologically similar. As in 
both localities the change from arenaceous to argillaceous is quite 
sudden, there would be hard boundaries in both places between the 
metamorphosed grits and the metamorphosed slates. 

In different places in Ireland there are tracts of gneissose rocks 
more or less similar to the Canadian Laurentians, yet evidently 
they belong to a newer geological group. Of these, those in the 
Carnsore district, S.H. Wexford, are probably metamorphosed 
Cambrians; while those of north Wexford, in the Croaghan Kin- 
shelagh range, undoubtedly belong to the upper group (“Slate 
Series”) of the Cambro-Silurians; those of the counties of Galway 
and Donegal in part belong to the Cambro-Silurian, and perhaps 
in part to the Cambrian.’ In Hrris, N.W. Mayo, they may be 


'TIn both these counties these gneissose and granitic rocks are evidently in part 
younger than associated rocks which are either unquestionably or probably of Cambro- 
Silurian age. 


Kinanan—On Canadian Archean, and Pre-Cambrian Rocks. 361 


metamorphosed Cambrians ; in east Mayo, Sligo, and Tyrone, they 
are, probably, Cambro-Silurians or Upper Cambrians; that is, the 
representation of the Arenig rocks of Wales; while in the county 
Antrim, in the Ballycastle district, they may be either Cambro- 
Silurian or Cambrian age. Lithologically, these are all similar, 
but in reality they are of very different ages. 

It should be pointed out that, as a general rule, hard, well- 
defined boundaries are characteristic of excessively altered rocks; 
while in unaltered rocks hard boundaries are the exception, one 
group usually graduating into another by alternations of the dif- 
ferent kinds of rocks; thus limestones in general graduate into 
shales, and the latter into grits; while grits will first alternate with 
shales before the latter entirely predominate. The subject of hard 
boundaries to metamorphosed rocks I have already discussed in 
Chapter X. of the “Geology of Ireland,” where it is shown that, in 
general, small metamorphosed tracts in large unaltered areas have 
hard, well-marked boundaries; while here I would point out that, 
in large areas of granitoid rocks, such as those of Galway and 
Donegal, there are proofs that the action which changed the 
rocks into their present condition invaded them long after their 
accumulation; as prior to their metamorphism they were up- 
turned, contorted, displaced by faults, while the consequent 
ruptures and breaks are now more or less sealed up. The 
breaks in the less altered rocks are much more numerous than 
in the granitoid rocks, those that are conspicuous in the latter 
being common to both. 

Many of the facts above mentioned respecting the Irish rocks 
may not bear directly on the Canadian Archean rocks; but 
they do so indirectly, as they show that too much reliance must: 
. not be placed on mere lithological characters. urthermore, al- 
though in the Canadian Archeans there are many rocks of which 
there are no equivalents in Ireland, yet in the latter country 
there are also many that are. It has already been shown that 
there is a great similarity between the gneiss and the calcareous 
rocks of the two countries, and this is even greater if we study 
the metamorphosed basic-eruptine rocks. In the section between 
Port Arthur and Winnipeg there is scarcely any rock of this class 
an equivalent of which could not be found in some one or other 


SCILNe PROC. L.D.S.==VOL. LV. PT. Vile 21 


362 Scientific Proceedings, Royal Dublin Society. 


locality of the Irish metamorphosed Cambrians or Cambro-Si- 
lurians.’ 

To return to the boundaries of the Ontario Laurentians and 
Huronians: it would appear to me that they are more lithological 
than stratigraphical, as in no place does there seem to be a regular 
unconformability or even an overlap of the Huronians on the 
Laurentians, while on both sides of the boundaries there are strik- 
ing similarities in the directions and dips of the beds in each class 
of rocks, while all the cracks and faults in the supposed older rocks 
occur also in the supposed newer. 

If it be allowable to compare small things with aren a paral- 
lel may be drawn between the section of the metamorphosed Cam- 
brians of the Forlorn Promontory, county Wexford, and that at the 
rapids out of the Lake of the Woods, one being a pocket-edition 
of the other. At the Forlorn section, going southward, we first 
meet typical schists, which are succeeded by gneiss, there being 
a hard boundary between the two; the gneiss, however, to the 
southward begins to alternate with beds of schist, and before the 
Point is reached all the rocks are schists. In the Canadian section, 
going northward, you first cross schists, then you come to a hard 
boundary, north of which is gneiss; but still further northward in 
the gneiss there are subordinate schists, which seem in one place to 
be of considerable thickness, as the water has cut out a very consi- 
derable bay apparently into rocks of a more frail character than 
the gneiss. 

I am aware that Sterry Hunt and others have suggested that 
these older rocks were accumulated under very different cireum- 
stances from the younger ones; they being in a great measure 
more chemical than sedimentary accumulations. Such a supposi- 
tion, however, appears to me, now that I have seen the Canadian 
rocks, to be unnecessary, if not untenable, as these supposed chemi- 
cal accumulations are in a great measure similar to much younger 
rocks in the Old Country, where their characters, as can be proved 
by ocular demonstration, are not due to chemical accumulation, but 
to metamorphic action ens subsequent to their first accumulation. 


1 Years ago I examined the collection of Canadian Archean rocks, sent over by 
Sir W. Logan to the Royal School of Mines, London, toillustrate his Report, and in them 
I only found a few rocks that did not occur in the Cambrians and Cambro-Silurians of 
West Galway. 


Kinanan—On Canadian Archean, and Pre-Cambrian Rocks. 363 


Some of the suggestions that I have made in this Paper may 
have been already published by American Geologists, who have 
had better opportunities than I have had of studying the rocks. 
Tf so, I apologize to them; but at the same time I would assure 
them that I am at present unaware of their having made the 
suggestions. 


NOTE ADDED IN THE PRESS. 


I learn from Dr. George Dawson that, during last summer’s work, 
some important changes, which are shortly to be published, have been 
made in the classification of the Labradorians or Norians. 


212 


set a 


XLV.—NOTES ON THE COAL SEAMS OF THE LEINSTER AND 
TIPPERARY COAL-FIELDS. By G. H. KINAHAN, 
MRT. A. &c. (Plate XIV.) 
[Read, January 19, 1885. ] 


Tue earliest attempts to classify the coal-seams of the Leinster 
and ‘Tipperary fields seem to have been those of Griffith, at the 
beginning of the century; the results of his explorations having 
been published about the year 1814. Many years afterwards 
Messrs. B. B. Edge, and A. Jacob proposed a different classifi- 
cation from that of Griffith for the coal-seams of the Leinster 
field ; and the latter, after I had examined the field, was adopted 
by Jukes in the *‘ Geological Survey Memoir,” published in 1859." 
After Mr. J. M‘Carthy Meadows had proved the coal in the new 
pit at Modubeagh, he, in the G'eological Magazine for March, 1874, 
advocated, for the most part, the classification of Griffith. 

As I have lately been able to examine the facts proved, or to 
be learned, from the pits and other workings in the district, since 
I examined the field in the year 1858, perhaps I may be allowed 
to lay the results of my investigations before the Society. 

In my “Geology of Ireland” it is pointed out that, in 1878, the 
section of the eastern portions of the Leinster coal-field was nearly 
quite clear; as also that of the central portion down to a certain 
depth; but that the relations between the coals of those portions 
of the field had not been proved; because in the central portion 
there were no coals nor measures, that could positively be stated to 
be the same as any of those in the eastern division. A general 
section of the measures that had been at that time, and have been 
since, proved in the central portion of the field has been compiled 
by Messrs. Popping and Edge, which proves a Crow coal about 
93 yards (279 feet) below the One-foot coal. 

In Meadows’ Paper (March, 1874) he states that he considered 
my classification wrong; as, instead of the Modubeagh coal being 
the representative of the “ Old Colliery Three-foot coal,” he believed 
that it was from 220 yards (660 feet) to 280 yards (840 feet) below 
it. ‘These thicknesses were from calculation, and therefore must 


1 About the year 1870 I modified the statements then published; which modifica- 
tions subsequently appeared in my ‘‘ Geology of Iveland,’’ chapter vi. 


KinwaHan—On the Leinster and Tipperary Coal Seams. 365 


be to some extent uncertain ; but the soundness of his views seems 
to be more or less proved from the subsequent researches by his 
assistant, Captain Sutcliffe. The latter investigator has carefully 
compared the measure passed through in the sinking of the new 
Modubeagh pit with those of the adjoining collieries; and from 
these comparisons he came to the conclusion that the trial at Mayo 
was in the same measures as those at Modubeagh. If this sugges- 
tion proves correct’ the great problem of the field is solved, and 
the measures ought to occur in an order similar to that given in 
Section 2, Plate XIV. 

The reasons for Sutcliffe’s supposition are as follow :—In the 
Modubeagh pit there is, at 50 yards (150 feet) from the surface, 
the Crow coal; while 70 yards (210 feet) lower down, or 120 yards 
from the surface, is the Fow/ coal (called in the adjoining collieries 
Ward’s Seam), the “ Main coal” being 48 yards (144 feet) lower, 
or 168 yards from surface. In the Mayo trial a Crow coal was cut 
at about 18 yards (55 feet) from the surface, and at about 61 yards 
(183 feet) deeper a second. The latter coal is not exactly similar 
to the Foul coal or Ward’s Seam, or at the same depth below the 
Crow coal; but the associated measures above’ and below it, as far 
as proved, are very similar to those in the Rushes and Modubeagh 
pits; on which account Captain Sutcliffe considers the coals to be 
the same. As already mentioned, there is, according to Popping 
and Kdge’s section, a Crow coal, about 93 yards (279 feet) below 
the One-foot coal, with which oceurs the Jarrow Channel, a Crow coal, 
the measures above and below which are more or less similar to 
those associated with the Upper coal in the Mayo trial, and those 
in connexion with the Modubeagh Crow coal, which has led Captain 
Sutcliffe to consider that in these sections there is found the 
representatives of one and the same coal (Modubeagh Crow coat). 
The comparison between these different sections appears to afford 
good presumptive evidence that the calculations of Messrs. Meadows 
and Sutcliffe are correct ; the main or profitable coal (Rushes coal) 
_ of the measures in the eastern division of the field lying about 209 


1 Mr. B. B. Edge points out ‘‘if the small coal in the AMnee pit is the representation 
of the Modubeagh Crow coal, there can be only tet feet between it and JVara’s Seam, 
and not 210 feet, as in Modubeagh.”’ 

2 In the Modubeagh pit there was a bed of fire-clay 21 feet over the Crow coil, 
while in the Mayo trial there is cne 13 feet above the thin coal. 


366 Scientific Proceedings, Royal Dublin Society. 


yards (627 feet) to 216 yards below the One-foot coal (Jarrow 
Channel) of the central division. At the same time this has not 
been positively proved; but a continuation of the Mayo trial to a 
further depth of about 25 to 385 yards (75 to 105 feet) ought to 
settle the question. 

Near Castlecomer Cottage, in the lane leading to the sandstone 
quarry, there is a hard, grey, calcareous shale containing Lower 
Carboniferous fossils. Jf Sutceliffe’s classification is correct, this 
should be found in the measures in the Modubeagh pits and the 
Mayo trial. But after minute inquiry I cannot find that any beds 
like it have been observed at either of those places. 


GenreraL Section (Caprains SurciirFE anp M&apows). 


Peacock or Surface coal, with 12 feet drift over it: 


Straten) o/c 21120) ees ee abouts 4o-tect— a lomyandes 
Stony coal : 

Sitreatiaa teats pel yeaa conta Ee Soh f DAL ke ee 
Double seam: 

GRE 3 ne Pe UI toe. ls, 


Old Colliery Three Wont eal: 
Strata with ‘“‘ Crow Coal ”’ about 
45 feet below Three-foot, . 
One-foot coal with Jarrow Channel: 


Strahan wume VC) aa ego) ei 1 oven 
Crow coal, Mouubeaghe 

Stratos pack ys ses tap A 00 2040 Osea 
Ward’s seam, or Foul re 

Straten a oe »: 2144 50= 48s 
Rushes, or Movubeagh eae 

Siete eo o o 6 o 6 Janie YK) 6 =O io 70 
Kingscote, or Bullring coal : 

Stratase osenes reta omiir i ey ki: 5 UD SOO og 
Gale Hill coal: 

Middle measures, . . . . . 5 OO 55 

Mower measures cars ne 5 UW =e 


Carboniferous limestone, 


The second, or Lower Towlerton coal, mentioned in my “ Geology 
of Ireland,” does not appear to be satisfactorily understood. To the 


Kryanan—On the Leinster and Tipperary Coal Seams. 367 


northward, in the Rushes Colliery, there does not appear to be any 
representation of it; but immediately north of Towlerton, in the 
townland of Woodlands, or Newtown Harpole, two coals are re- 
corded ; while it was also found in some of the pits in Towlerton ; 
but in other pits, sunk to search for it, it was not found. Possibly 
here, as at Coorlaghan, there may be in places a “splice,” being 
portions of the one bed with a “horse” between them, or, as sug- 
gested by B. B. Edge, there may be an overlap, as found in the 
Doonane Colliery. In the Newtown Harpole bore-hole, and in 
one pit in Towlerton, there was about 50 feet of strata between the 
two coals; elsewhere, however, in ‘lowlerton, it is said to have 
risen up towards the Old Towlerton coal. 

Since the year 1859 the continuous workings on the Jarrow 
Channel have proved it to be a rather remarkable accumulation. In 
1859 it was generally supposed to have some sort of a connexion 
with the One-foot coal, but the relations between the two were quite 
obscure; some ten or more years afterwards, when a pit had been 
sunk and workings commenced on the portion of the channel under 
the Clogh royalty, the proprietors ran a drive northward, for 680 
yards, which proved that the Jarrow coal lay in a washout or 
channel ; the coal at the margin of the channel joining into the One- 
foot coal. The accompanying section, Pl. XIV., fig. 1, for which I 
am indebted to Mr. Meadows, is a tracing from the working plan. 
From this we learn that for 264 yards the floor of the coal rose ; while 
on the brow of the rise it joined into the One-foot coal, “a regular 
coal” on a “fire-clay and seat;”’ while under the coal of the 
channel “there is no fire-clay or seat, there being only a sort of 
shaly seam between it and the country rocks.” (See note at end.) 

The washout, in which the Jarrow Channel occurs, is both im- 
portant and peculiar: 

If the great N.H. and 8.W. Coolbaun fault be taken as a base, 
to the northward of it, this washout forms a more or less regular 
horse-shoe, extending from the Geneva Colliery, on the east, 
northward along the valley of the Dinan to Clogh, and thence 
westward to Massford, and southward to Coolbaun. South of the 
N.E. and S.W. Coolbaun fault the exact position of the channel 
has not been proved, as the only workings are to the eastward, at 
Monteen and Kilgorey, and to the westward, at the Rock Colliery 
(Augharenagh), places lying nearly east and west of each other. 


368 Scientific Proceedings, Royal Dublin Society. 


Tn connexion with the Rock Colliery, Mr. Joseph Dobbs points 
out that no batrachian or other fossils, such as have been found in 
the northern channel, have been there met with; and he suggests 
that possibly there might have been two channels in connexion 
with this One-foot coal—that to the north or the Jarrow Channel 
being separated some way or other from the South or Rock and 
Kilgorey Channel. The measures found in connexion with the coal 
of the Jarrow Channel, when compared with those found in con- 
nexion with the coal of the Rock and KKilgorey Channel, may add 
weight to Mr. Dobbs’ suggestion. 

To the northward of the Coolbaun fault there is a remarkable 
circumstance connected with the washout, which is, that the present 
valley of the Dinan river nearly coincides with it. Whether this 
is a mere accidental coincidence or is due to some natural cause it 
is hard to determine. 

The accompanying section (Pl. XIV. fig. 1), with the small 
section (fig. 2), represent the character of the channel as proved in 
the Clogh and Jarrow Collieries ; while the old working at Geneva, 
to the 8S. E., and the new ones at Massford, to the westward, 
suggest that in those places also the channel is of a very similar 
character and width. 

From this section it would appear as if the full channel was, 
on an average, about 350 yards (1050 feet) wide, while the profit- 
able coals in its deepest portion were not more than 200 yards 
(600 feet) wide ; the greatest depth of coal being four feet, which 
more or less gradually lessened towards the margins, especially the 
north margin. 

Another peculiarity of the Jarrow Channel, which does not ap- 
pear in Meadows’ section on account of its small scale, is that, as 
we proceed towards the edges, especially southward, eastward, and 
westward, there are breaks or sudden lessenings of the thickness of 
the profitable coal, locally called “troubles,” or “ faults.” This 
phenomenon is roughly represented in the sketch (fig. 2). The 
roof is continuous ; but the floor of the coal rises, and on each rise 
or “trouble” (at a, a, a) there is only a sort of clayey culm, or 
buddagh, i.e., a mixture of coaly and clayey or shaly matter; 
while at both sides of the “trouble” the coal is found: on the 
channel side it is usually of the regular thickness, while at the 
other, or towards the edge of the channel, the coal gradually 


Kinanan—On the Leinster and Tipperary Coal Seams. 369 
thickens, to thin again when the floor rises. These phenomena, in 
connexion with the formation of the channel, appear important, as 
will be mentioned hereafter. 

It appears necessary to point out here, that in my previous 
writings and in those of later observers, a very important con- 
sideration has been omitted, or rather mis-stated, as the promis- 
cuous calling of the seam One-foot coal and Jarrow coal leads to an 
erroneous impression ; because although they are eonnected, the 
latter being an adjunct of the former, the One-foot coal is perfectly 
distinct from the Jarrow Channel; for although both may have 
been accumulating at one and the same time, their modes of for- 
mation were very different; one being almost entirely a drift 
accumulation, and the other a growth in situ. I have not met 
with any description of a coal similar to that in the Jarrow Channel, 
but the probable explanation of its peculiarities would appear to 
be suggested by what can be observed as going on at the present 
day in various places in the Irish bogs. Numerous cases could be 
mentioned, both in the Irish lowland or Red Bogs, and in the 
mountainous districts. I will, however, draw attention to but one 
locality, which is specially illustrative—that is to say, the level 
bog-land in the neighbourhood of Muckanaghederdanhalia, Conne- 
mara, West Galway. In this locality there is a great expanse of 
low bog-land intersected by more or less regular wash-outs ; some 
of the latter being fiords, while the majority of them are now 
marshes or sloughs ; the latter having been, or being now filled in, 
by materials carried by wind, rain, and runlets from the adjoining 
flats, aided by the growth and decay of vegetation ; while on the 
adjoining flats peat is accumulating in the ordinary way—that is, 
by the growth and decay of vegetation in situ. Some such more 
or less similar operations must have been going on in Carboniferous 
times, to account for the formation of the Jarrow Channel. The 
One-foot coal seems to be of a somewhat similar origin to the flat 
bog, being due to the growth and decay of vegetation im situ, 
while through it there ran a washout, now the Jarrow Channel ; it 
having been subsequently filled in by argillaceous and vegetable 
matter carried into it by wind, rain, and runlets, the accumulation 
being aided by the growth and decay of aquatic plants. Besides 
the plants in the nearly stagnant or sluggish waters, there lived 
fish and batrachians ; and these, in course of time, as the filling-in 


370 Scientific Proceedings, Royal Dublin Society. 


process proceeded, were pounded into smali spaces, when eventu- 
ally they died, and were buried.!. The character of the channel 
and its accumulations would appear to suggest such conclusions ; 
as the form is so similar to those in our flow-bogs or sloughs, 
while the steps (¢rowb/es) in the floor of the coal are similar 
to those under such peaty accumulations. Moreover, all of the 
channel accumulations are, for the most part, sedimentary, except 
perhaps the Bottle coal. This coal is peculiar; its name having 
arisen from the great similarity, both as to appearance and frac- 
ture, between it and bottle glass. Its origin is puzzling; as al- 
though in some places it appears in mass, in others it is mixed 
up irregularly with the members of the regular stratified accumu- 
lations; and nowhere, as far as I could see, has it a lining struc- 
ture to suggest that it was either a sedimentary deposit or due to 
the annual growth and decay of vegetation.” 

At the time Mr. Meadows published his classification of the 
Leinster coals, he endeavoured to frame a scheme of correlation 
between them and those of the Tipperary or Kast Munster coal- 
field ; but a comparison between the Sections 1 and 2, Plate XIV., 
demonstrates how fruitless any such attempt must be. 

On examining the different published records of the Tipperary 
field, it will be seen that al coals, no matter how valueless, are given 
a place and a name—thus giving them an undeserved value. 
While, on the other hand, in all the records of the Leinster field, 
more or less of the minor coals are left out, although they are just 
as important and continuous as the minor coals in the Tipperary 
field. his, therefore, is a unique feature in Section 2, Pl. XIV., 
as in it all the minor or Crow coals that are continuous, being 
recorded in the different sections of pits and bore-holes, are given 
in their proper places. ‘This appears expedient, as they are very 
valuable indications to the colliers as to the depth at which they 
will probably find the different coals which they overlie. 

I would here again specially mention, as has already been done 


1 The above seems to be now the general idea in reference to the Jarrow Channel ; 
as I have heard very similar notions expressed by Messrs. Edge, Meadows, and Dobbs. 

® Tt has somewhat the appearance of a chemically formed, or partly chemically 
formed, rock. This, however, may have been induced by the” metamorphic action 
that has more or less changed the rocks of these and the majority of the Ivish 
Coal Measures, 


Kinanan—On the Leinster and Tipperary Ooal Seams. 3871 


in my “Geology of Ireland,” that in regard to the Co. Tipperary, 
“Tn this field every stratum, from the highest in the limestone 
to the highest of the coal-measures, can be seen and measured.” 
All the strata between the Upper Glengoole coal and the Main 
coal were hammered and measured by the late Mr. O’Kelly, 
Mr. Wynne, and myself, in the Glengoole level, while subsequently 
they were re-measured by O’Kelly. Moreover, there is on the 
surface a very continuous section, which was carefully examined 
and measured by O’Kelly and myself, and subsequently by the 
late Mr. Jukes, accompanied by O’Kelly. I am informed by 
Mr. Meadows that he not only examined and measured this sec- 
tion, but also others in the field, and found O’Kelly’s measure- 
ments substantially correct: if anything out, they are alittle short 
of the actual thickness. It may be mentioned that from the 
measurements given by the Glengoole level, Mr. O’Kelly and 
myself were able to localize the outcrop of the coal that was 
afterwards wrought between the Collieries and Killenaule. 

Of the eight coals that appear in Section No. 1, three at 
least—the Stinking coal, Maher’s Vein, and Hanley’s Vein—are 
commercially valueless; while the total thickness of the measures 
in which the coals occur is about 1200 feet. 

In the Leinster coal-field there are at least eleven coals and per- 
haps twelve (Lower Towlerton). Of these, the Gale Hill, Modubeagh, 
Crow, and Jarrow Crow coals, are commercially valueless ; while the 
Kingscote or Bullring, the Ward or Foul, and the One-foot coals 
(irrespective of the Jarrow Channel) are not of much account; the 
more profitable coals being the Modubeagh or Rushes, the Jarrow 
Channel, portion of the Foot coal, and the old Three-foot coal; these 
occurring in a thickness of strata of about 1500 feet. ‘There were 
also the upper coals in Coolbaun Hill that are now worked out. 

The Sections Nos. land 2 indicate that in the lower portion of 
the Leinster section there are more coals than in the correspond- 
_ ing thickness of the Tipperary section; also that opposite the 
portion of the latter, in which thev aluable coals occur, there are 
no coals of any value in the Leinster section, except the Jarrow 
Channel, which is not a regular coal, being uly an accidental 
adjunct to the One-foot coal. 

It may be said that as the lower and middle measures of the 
Tipperary field are about 1500 feet thick, while those of the 


302 Scientific Proceedings, Royal Dublin Society, 


Leinster field are only about 1300 feet, the difference should be 
taken off the base of the coal-bearing portion of the latter; but 
even if this were done (which, I believe, would be absurd, as the 
measures below the Gale Hill and Stinking coals are very similar) it 
would not mend matters; not even if 300 feet were taken from it, 
and the Kingscote coal was supposed to represent the Stinking vein. 
In the latter case the Mai coal would be about opposite the One- 
foot with its Jarrow Channel ; but none of the other workable coals 
would come in at about similar heights. 

From the facts that have been proved from the examination of 
all the Irish coal-fields, it appears a waste of labour and an unprofit- 
able task to attempt a correlation of the Irish coals; as it has been 
proved that, although the Irish Coal-measures, as a mass or group, 
were accumulating at one and the same time, the individual accu- 
mulations were of different characters, even at places not far apart, 
this being specially the case in reference to those due to vegetable 
decay or the mineralizing of vegetable matter ; none of the latter 
being on similar horizons, or even on nearly similar horizons, 
except perhaps the lowest coal of the different fields. Thus in the 
eastern portion of the Leinster field there appears to be in an equal 
thickness of strata more coals than in the western portion ; while 
in similar thicknesses of the Leinster and Tipperary fields there 
are more in the latter; and in the Cork field more than in either. 
But if we go north from Cork into Limerick, Kerry, and Clare, the 
number, thickness, and quality of the coals rapidly changes; they 
being at the lowest in every way in the county Clare, and perhaps 
county Kerry. Itis unnecessary to mention the coals of Ulster and 
Connaught, which differ so completely, as to their circumstances, 
from those which form the subject of this Paper. 


NOTE ADDED IN THE PRESS. 


It has been pointed out by Captain Sutcliffe, and can also be seen in 
the section, Plate XIV., fig. 2, that the thickness of the strata between 
the Three-foot coal and the Jarrow coal increases from the edge of the 
Channel to its centre, from 209 yards to 216 yards; while the underlying 
black shale has increased from a foot in thickness, at the edge of the 
Channel, to twelve feet or more at the centre or deepest portion. 

A copy of Popping and Edge’s section is deposited in the Mining 
Record Office, London. 


0 


XLVI.—ON TRILOBITES AND OTHER FOSSILS, FROM LOWER 
OR CAMBRO-SILURIAN STRATA, IN THE COUNTY 
OF CLARE. By WILLIAM HELLIER BAILY, F.G:S., 
&e. 


[Read, January 19, 1885. | 


Tue fossils I bring before your notice were described in the ex- 
planations to Sheet 133 of the Map of the “‘ Geological Survey of 
Ireland,” illustrating a portion of the county of Clare. 

They were first discovered by Mr. G. H. Kinahan and myself, 
in a small exposure of light-brown shales, in the townland of 
Ballyvorgal south, on the western extremity of the Shevebernagh 
Mountains, near Six-mile-bridge. 

These fossils consist principally of trilobites, of the following 
genera and species :—Dindymene Haidingert (Barrande), Afglina 
rediviva, Staurocephalus globiceps (Portlock) (probably identical with 
S. Murchisoni) ; Remopleurides, sp. perhaps Colbi (Portlock): Tii- 
nucleus concentricus, and Agnostus trinodus, with the brachiopods 
Orthis calligranuma, var. virgata, and O. elegantula; and a pteropod 
Theca triangularis, all characteristic of Lower or Cambro-Silurian 
strata of Caradoc Bala age. The first-named of these trilobites, 
identified by me with Dindymene Haidingeri, is new to Britain, 
occurring, I believe, in Bohemia. It is figured and described by 
Barrande in his fine volume on Trilobites, in his “‘ Systéme Silurien 
du centre de la Bohéme,”’ Ist part Palzeontologie, vol. 1, as charac- 
teristic of his fauna seconde, equivalent to Caradoc Bala strata. 

At Belvoir, about half a mile south of Crag-bridge, there is 
another interesting section, described by Mr. Kinahan, also on the 
western flank of the Slievebernagh Mountains, where a section of 
black slates is exposed, Graptolites being the prevailing fossils. 
Their impressions, double forms of Diplograptus pristis, together 
with the coiled genus Rastrites peregrinus, are most beautifully 
impressed upon the shales. 


ore 


XLVII—ON THE PHYSICAL CHARACTERS OF CALCAREOUS 
AND SILICEOUS SPONGE-SPICULES AND OTHER 
STRUCTURES. By PROFESSOR W. J. SOLLAS, M.A., 
D.Sc., F.R.S.E. (Plate XV.) 


[Read, January 19, 1885.] 


Srzicrous SkELEtTons.—Although in the great majority of existing 
sponges the skeleton is of a siliceous nature, it was supposed, until 
quite recently, by paleontologists, that in nearly all fossil sponges 
it was originally, as it usually is now, calcareous in composition ; 
but since in structure it seemed to offer in no case any point of re- 
semblance to that of existing calcisponges, it became necessary to 
refer the fossil sponges to an extinct order, rélated to the existing 
calcareous sponges simply by the chemical composition of the skele- 
ton, and not in any way by its structure. In 1877, however, Pro- 
fessor Zittel and myself showed that the majority of fossil sponges 
are characterized by skeletal structures which resemble in the closest 
manner those of existing siliceous sponges, and we accordingly 
inferred that, originally siliceous in composition, they had since 
become calcareous. Such a substitution as this involved appeared 
to most geologists improbable, and some chemists went so far as to 
assert that it was impossible. It has now, however, become one of 
the accepted facts of science. 

The difficulty which was felt in admitting such a substitution 
was no doubt due to an ambiguity of terms. ‘Suiliceous” and con- 
sisting of silica were regarded as synonymous expressions, and we 
cannot wonder that a chemist would refuse to believe in the possi- 
bility of calcite replacing quartz. But in my Paper on Pharetro- 
spongia I pointed out that the siliceous material of sponge-skeletons 
differs very widely from quartz in its physical characters. “The 
latter is to all intents perfectly insoluble in carbonated waters, and 
most other solvents; it is crystalline, with a comparatively high 
refraction-index, and is composed solely of oxygen and silicon. 
The former, on the other hand, is coiloidal, with a comparatively 
low refraction-index, is soluble in caustic potash and carbonated 


Sorzas—On Sponge Spicules. 875 


waters, and consists of silica (probably one of the silicic acids) in 
intimate combination with organic matter.” ! 

More recently M. Thoulet,? to whom apparently my results 
were unknown, has made some experiments which completely — 
confirm the preceding statements, except with regard to the 
presence of organic matter in the sponge-silica. M. Thoulet 
found that by calcination certain sponge spicules which he ex- 
amined lost 13°18 per cent. in weight; their specific gravity was 
determined to be 2:0 3861 at 16°5° C.; and hence M. Thoulet con- 
cludes they are to be regarded as opal, which is only another name 
for consolidated colloid silica. My attention having been re- 
directed to this subject by M. Thoulet’s observations I wished to 
determine exactly the refractive index of sponge-silica, but was 
met at once with a difficulty due to the form of the spicules, their 
shafts being more or less cylindrical, so that their surface is 
always strongly curved, never plane. It then occurred to me to 
take advantage of the fact that a solid body becomes invisible, or 
nearly so, when immersed in a liquid having the same refractive 
index as itself. ‘The problem then was to find a fluid in which the 
sponge spicules could no longer be seen. Knowing the refractive 
index of this liquid, the refractive index of the spicules would also 
be known. Experimenting with various kinds of sponge spicules, 
including fragments of Lithistid skeletons, I found that the nearest 
approximation to invisibility, as seen under the microscope, was 
obtained when they were viewed mounted in chloroform, which 
possesses a refractive index of 1-449. This is very nearly the same 
as that of iridescent opal (1°446). Some colloidal silica, which I 
prepared some five years ago, and which has been hardening ever 
since, gave a refractive index ofi|1-47, being least visible when 
mounted in glycerine. 

The refractive index of sponge-silica is therefore that of opal 
or colloidal silica, and not of quartz, and thus my earlier state- 
ments, and those later of M. Thoulet are confirmed. All difficulty, 
therefore, with respect to the substitution of calcite for silica in 


1 Sollas ‘‘ On Pharetrospongia Strahani;’’ Quart. Journ. Geol. Soc., vol. Xxxiil. p. 
254, 1877. 

2 Thoulet.—<“ Sur les spicules siliceux des éponges vivant.’’ Compt. Rendu. xcviil. 
pp. 1000-1. 


376 Scientific Proceedings, Royal Dublin Society. 


sponge-skeletons is removed. Since diatoms and the siliceous 
teeth of molluscs have the same refractive index as sponge- -spicules, 
we may consider it probable that the silica of Orpen generally 
exists as opal. 

The method of determining refractive ‘ndlenee just described 
admits of a wide application, and with isotropic substances presents 
no difficulties; it may often be employed in many cases where 
other methods are impracticable. Thus I find that the glass of 
the Krakatoa ashes has a refractive index of about 1°51, and it 
would be possible to obtain a closer approximation than this were 
one furnished with a refractometer to determine the refractive 
index of the liquid employed: as it is 1 am obliged, when using a 
mixture of two liquids in order to obtain a mean, to find its refrac- 
tive index by discovering what mineral of known refractive index 
disappears when immersed in it. The test mineral thus serves as 
a refractometer. J intend, however, for laboratory purposes, to 
provide myself with a series of fluids; each with an accurately 
determined refractive index, and ranging from 1:3 to 2:0, with a 
difference of 0°002 between each. One would then make coarse 
adjustments up to the second place of decimals, and conclude by 
obtaining results up to the third place. Of course accurate results 
can only be obtained by the use of monochromatic light, which 
should be similar to that of the mineral under examination. 

The method provides an easy means of discriminating between 
similar species of minerals. ‘hus, leucite and analcime often: 
closely resemble each other ; and without finding the exact vanish- 
ing fluid, it is sufficient for their distinction to place them either in 
oil of santal, when the leucite becomes almost invisible, while the 
analeime stands out in sharp relief; or in linseed-oil, when the 
analcime is least visible, and the leucite most so. 

With anisotropic substance the case is different ; but the addi- 
tional difficulties which these present may be met by the use of 
polarised light, at least when the mineral possesses planes of 
cleavage. ‘Thus, to take the case of aragonite and calcite. We 
view them under the microscope between crossed nicols, a plate 
of quartz being interposed to restore the light. The fragments of 
both minerals are, to a great extent, bounded by cleavage planes. 
In aragonite the indexes are—minimum, 1:530; mean, 1682; 
maximum, 1-686: in caleite, »* = 1-486, +” = 1°659; the value of 


Sortas—On Sponge Spicules. 377 


r* will never, however, be this minimum; but for light passing 
perpendicularly through a cleavage fragment lying with one face 
on the microscope slide is about 1°56. If now both minerals be 
viewed mounted in Canada balsam (r. 7 = 1:525), or oil of cloves 
(7. 7 = 1:535), most of the calcite will never cease to show relief 
as it is rotated between the nicols; the aragonite, however, under- 
goes a marked change; parallel to the principal section of one 
nicol it stands out in bold relief, like a projecting rock; as it is 
rotated, it begins to flatten down, the brilliancy about its edges 
and angles fades, and, finally, when it has been rotated 90°, it has 
lost all relief, and appears as the merest film flattened out in the 
plane of the glass slide. The experiment is a striking one, and 
the discrimination between the two minerals may in this way be 
made in a very short time—a few minutes will suffice. 

Another application will be found later on, where the refrac- 
tive index of a calcite spicule lying in a definite position, having 
been determined for the extraordinary rays, the position of the 
optic axis can be deduced. 

Specific Gravity—By a method described later on, the specific 
gravity of the acerate spicules of a Renierid sponge, of a frag- 
ment of a Lithistid sponge skeleton, and of various diatoms, was 
found to be 2°04, a result in close agreement with that found 
by M. Thoulet for Hexactinellid sponge spicules. ‘The reference- 
minerals (a term which will be understood after reading the 
description of the method) employed in this case were crystals 
of sulphur deposited from solution in carbon disulphide, and 
fused sulphur: the specific gravity of the latter is 1:98; of the 
former, 2:05. 

Calcareous Skeletons —Amongst the fossil sponges are some 
which, in 1877, offered great difficulties to the paleontologist. 
Professor Zittel regarded them as calcisponges, while I was 
inclined to group them with the siliceous sponges, at the same 
time expressing great uncertainty on the point.’ Since then, the 
discoveries of Hinde and Dunikowski have thrown more light on 
these previously-obscure ‘“ Pharetrones,” and I have now not the 
least doubt that they must be relegated to the Calcispongiz. 


1 Sollas, ‘On the Genus Catagma,’’ Annals and Mag. Nat. Hist., ser. 6., vol. ii., 
p. 368. 
SCIEN. PROC. R.D.S.—VOL, IV. PT. VII. 2K 


308 Scientific Proceedings, Royal Dublin Society. 


Pharetrospongia, however, is not one of the Pharetrones, and is 
as certainly a siliceous sponge as they are calcareous. 

Some observers have gone so far as to deny the possibility of a 
calcisponge being preserved in the fossil state, alleging that cal- 
careous spicules, when kept in distilled water, decompose in the 
course of a year; as, however, I have calcareous spicules in my 
possession, which are as perfect now as they were originally, when 
placed in distilled water ten years ago, the force of this argument 
is weakened. 

It becomes interesting to inquire, however, into the mineral 
state of calcareous spicules, 7.¢. whether they are composed of 
calcite, or aragonite, or of some combination of calcareous and 
organic matter. If we find that they consist of calcite, we shall 
have no difficulty in concluding that they may well be preserved 
in a fossil state, but the contrary, if they consist of aragonite ; or, 
at all events, in the latter case their preservation will be rare and 
exceptional, and their structure will wholly disappear. As every- 
one, without inquiring into the matter, seems to have regarded 
them as calcite, I was quite prepared to find the contrary; the 
result, however, of my observations will appear in the sequel. 

Refractive Index.—Most of the acerate spicules of Grantia 
ciliatia and Girantia compressa, the species with which I chiefly 
worked, disappear when observed between crossed nicols, in linseed 
oil, along one line of extinction (light being restored by a quartz- 
plate): along the other line of extinction, at right angles to the 
former, all the spicules disappear when viewed in carbon disulphide 
containing a little sulphur; their refractive indexes are then «= 1-485 
and w = 1°650, most nearly agreeing with those of calcite. 

The invisibility of the acerate spicules when mounted in linseed 
oil, and at the proper angle of extinction, is often absolute; they 
cannot be seen even with strong illumination under a Zeiss C. 

Specific Gravity.—The difficulty of determining the specific 
gravity of calcareous sponge spicules by the methods of weighing, 
I found insuperable. They are so small, and so difficult to free 
completely from air, even with an air-pump, that I had to adopt 
some other method. Sonstadt’s solution appeared to offer the 
best chance of success; but here again the small size of the spicules 
was a difficulty. This, however, was overcome by adapting the 
Sonstadt method to use with the microscope. An ordinary col- 


Sottas—On Sponge Spicules. 379 


lecting tube, fig. 1, T, about 2 inches long, and 2-inch in diameter, 
was cemented with plenty of Canada balsam to a glass slide, as in 
the illustration. 


Fie. 1. 
Arrangement for determining the density of minute objects under the microscope. S, stage of 


the microscope; Sc, and Scz, the two scales; G, glass slide carrying the observation 
tube, T. 


The object of using excess of balsam was to destroy optically 
the curvature of the side of the bottle. As the refractive indexes 
of Sonstadt’s solution and balsam are not very different, this 
plan succeeded admirably. A thin cover-glass was similarly 
cemented to the opposite side (front face) of the bottle, which was 
thus optically flattened, front and back. Some Sonstadt’s solu- 
tion (sp. gr. 2°77) being introduced, a fragment of aragonite (sp. 
gr. 2°9) was dropped in; it at once, of course, sank to the bottom. 
Next, a piece of calcite (sp. gr. 2:7) was added; it floated on the 
surface. ‘The spicules, lying in water, were freed as far as possible 
from air by boiling, and with the air-pump. With a dipping-tube 
the water and spicules together. were taken up and added to the 
top of the Sonstadt’s solution, where they floated. The tube was 
then left to stand in order that diffusion might take place. After 
some hours the water and Sonstadt’s solution had become gradually 
mixed, giving a column of fluid with a specific gravity of about 2:4 
at the top, and 2°77 at the bottom. The calcite and the spicules 
floated at different levels (the spicules being above), in layers of 
fluid having respectively the same specific gravity as themselves. 


A fragment of pure quartz (sp. gr. 2°65), and another of adularia 
2K 2 


380 Scientific Proceedings, Royal Dublin Society. 


felspar (sp. gr. 2°58) were next added; the quartz sank to a level 
below the spicules, the felspar remained above. As the contents 
of the tube could be easily examined under the microscope with a 
1-inch or even a t-inch lens (Zeiss’s C), one could make certain of 
the absence of air bubbles, vacuoles, or other troubles; and as the 
spicules could be seen individually, it was possible to determine the 
specific gravity of a single one. The spicules did not all lie at 
exactly the same level, but formed a zone thickest towards the 
middle, and thinning off above and below; a few stragglers were 
seen at some distance on either side, but this was owing either to 
adhesion to the side of the tube, or attached impurities. 

The specific gravity could now be exactly determined. Two 
rectangular axes are ruled, fig. 2; on one distances are taken to 
represent the densities of the calcite, quartz, and felspar; on the 
other the exact distances between the middle line of each fragment 
as,it floats in the tube are measured off. 

These distances were obtained by gumming two scales divided 
into millimeters on the stage of the microscope, at right angles to 
the glass slide carrying the experimental tube, 7. e. parallel to this 
tube (fig. 1, Se, and Se,). The calcite was brought into focus, and 
the position of one edge of the glass slide read off on the scales; 
the slide was then moved down till the quartz came into view, and 
the position of the slide again read off on the scales. ‘T'he object 
of having two scales is obviously to ensure parallelism in the move- 
ments of the glass slide. 

The specific gravities and distances being indicated on the rect- 
angular axes, one constructs a curve which gives the change in 
density from one mineral to another in the tube. 

The height of the zone of spicules being now indicated on the 
axis of distances, a line is drawn parallel to the other axis through 
it; from the point where it cuts the curve a perpendicular is let 
fall on the axis of specific gravities, and the point where it meets 
the axis gives the specific gravity. In this way the specific gravity 
of the spicules was determined to be from 2°61 to 2°63. They 
are plainly, therefore, not aragonite, and, arguing from the specific 
gravity alone, probably consist of calcite. The slight difference 
between it and them in specific gravity is no doubt due to the pre- . 
sence of organic matter ; for within, a minute canal, filled with some 
kind of organic material, possibly spongin, occurs in the axis of the 


Sortas—On Sponge Spicules. 381 


spicules; and without they are surrounded by a thin sheath of a 
probably similar material. I find by calculation that, allowing for 
the organic matter a specific gravity of 1-5, it would require to be 


Fig. 2. 


Avila arse sp hie stack cen Gee 
An occasional spicule, . .. .- 


Middle of zone of calcareous senles oe 
Beginning of same zone, . 


Quartz and perforate ree = 


Perforate foraminifera (lowest lying 
Examples) Wasa merce cpm 


2.67 2.65 203mm 2.02 2.58 


a. Axis of distances. 6. Axis of specific gravities. 


present to the extent of 62 per cent. to reduce the total specific 
gravity of the spicules from 2°7 (supposing them to consist chiefly 
of calcite) to 2°62, the density found. 

Optic Axis and Angles of Extinction—Lying on the borders of 
the organic and the mineral worlds, the spicules of calcisponges 
offer many interesting problems for consideration. ‘Their outer 
form, moulded by the organism, offers no crystalline outlines; 
their molecular structure, as will appear from the next series of 
investigations, is purely crystalline, not differing from that of 
calcite. 

Heckel, in his work on the calcisponges, regards the regular 
triradiate spicules as having a crystalline form, derived from a 
regular 12-sided pyramid; but as one cannot derive the angles of 
the sagittal and irregular triradiates by any known laws of crystal- 
lography from the more regular forms, one fails to see the grounds 
for such a view. The existence of precisely similar regular and 
sagittal triradiates amongst the siliceous sponges in which the 
mineralizing matter is purely colloidal also makes against this 
opinion. Were the regular triradiates of Heeckel placed within a 
scalenohedron in the position his view requires, the optic axis would 
pass through the centre of the spicule at right angles to its plane, 
and consequently, on viewing it through crossed nicols, it would 
remain obscure during a complete rotation about its axis in the 


382 Scientific Proceedings, Royal Dublin Society. 


plane of its surface. This never happens with any of the trira- 
diates of Grantia ciliata and Grantia compressa ; but in a Leuconia, 
L. botryoides, which I have examined, many of the triradiates do 
fulfil this condition, remaining constantly extinguished as they lie 
flat on the microscope slide, between crossed nicols. In these re- 
gular triradiate forms the optic axis passes then through the centre 
of the spicule perpendicular to its plane. 

This is not the case, however, with all, or indeed the greater 
part of, the triradiates of this species; most of them behave in the 
same manner as the sagittal and all the other triradiates of Gran- 
tia compressa and G'. ciliata; these appear brilliantly illuminated 
between crossed nicols; but on rotation they extinguish in four 
positions at right angles to each other. In these positions it will 
always be found that one ray of the triradiate lies parallel to the 
long diagonal of one nicol, ¢.e. in the plane of its principal section. 
With the sagittal spicules it is the unpaired ray that has this posi- 
tion; with the regular and sub-regular triradiates, it may be any 
one of the three rays. In the same way the quadriradiates extin- 
guish ; and in their case it is always the apical ray which lies in 
the principal plane of the nicol at the time of extinction. The 
optic axis must also lie in this plane, and thus the morphological 
axis of the unpaired ray and the optic axis of the sagittal spicule 
are in the same plane which is at right angles to the plane of the 
spicule (fig. 3). 


Fic. 3. 


Longitudinal vertical section through the middle of an unpaired ray of a sagittal spicule, showing 
the position of a principal section, 0 da @’; of the optic axis, 0a; and an axis of maximum 
elasticity, ee’. A ray of light passing perpendicularly through the spicule is shown by 77’. 


The spicules behave as single individuals, all parts becoming 
extinguished and illuminated together ; so that while the optic axis 


Sorras—On Sponge Spicules. 383 


lies in the median plane of symmetry of the unpaired ray, it crosses 
transversely the median plane of symmetry of the paired rays, which 
make an angle of from 90° to 120° with the unpaired ray. 

I may now allude to a curious difference between the refractive 
index of the triradiate and the acerate spicules of Grantia. The 
latter, as we have already stated, have a refractive index of 1:485; 
the former, on the other hand, disappear in balsam (v. 7. = say 1-520 
to 1:525) when viewed by the extraordinary rays which vibrate in 
the principal section of the analyser. Hence the axis of maximum 
elasticity, which lies at right angles to the optic axis in the same 
plane, cannot be vertical to the plane of the spicule, but is inclined 
from it at an angle of 55° to 60°, or at 30° to 35° from the common 
axis of the nicols: and the optic axis consequently makes an angle 
of 30° to 385° with the plane of the spicule, or of 55° to 60° with 
a vertical ray of light (fig. 3). 

Although the triradiates and quadriradiates extinguish when one 
ray is parallel to either diagonal of the nicols; yet the parallelism 
is not always exact, the difference often amounting to 8° or 10°. 

The acerates of Grantia extinguish at about 20°; the angle 
varying about 10°, but usually much less, on each side of this. As 
they become invisible at this angle, when mounted in balsam and 
viewed by the extraordinary rays which vibrate in a plane at right 
angles to the principal section of the analyzer, it follows that the 
plane of the principal section of the analyzer then cuts the spicule 
transversely to its length at an angle of 70° (fig. 5); and next, that 
an axis of maximum elasticity at right angles to the optic axis lies 
vertically in the spicule, and hence that the optic axis is horizontal. 

The club, or retort-shaped, spicules of Grantia extinguish when 
the long ray makes an angle of 30° with a diagonal of the nicols; 
the thick, short ray then extinguishes, according to the angle it 
makes with the long ray, at from 10° to 30° (fig. 6). . 

A comparison of the relations of the spicules to each other, as 
shown in figs. 4 to 6, will show that the acerate spicules are not 
homologous, as one might have suspected, with the unpaired ray of 
a sagittal spicule, but with one or both of the paired rays, probably 
with both; since in many of the sagittal spicules these rays both make 
an angle of almost 90° with the unpaired ray, when they are both 
nearly in the same straight line. The club-shaped spicule also 
probably corresponds to the paired rays of the sagittal. It may be 
that we are not justified in thus determining homologies by means 


384 Scientific Proceedings, Royal Dublin Society. 


of polarised light; but this introduces questions too wide for profit- 
able discussion in this place. 
0 


oO 
a 
Fig. 5. 
oO 
Py, a 
Fia. 4. Fie. 6. 


Showing the positions in which the spicules of Grantia compressa extinguish between crossed 
nicols. oa, line of intersection of the plane of the principal section of the analyzer with 
the spicule: the optic axis lies in this plane. 


Finding in my collection a slide on which I had mounted spi- 
cules from an unidentified calcisponge from Port Elizabeth,’ possess- 
ing acerates of a colossal size, | turned to examine the extinction 
angles for these, and obtained results closely agreeing with those 
for Grantia. The sagittal spicules of this sponge are distinguished 
by a particularly long unpaired ray: out of 10 examples, 5 ex- 
tinguished at 0°, and 5 at 10°; the acerates extinguished at from 
13° to 19°. 

Etch-figures.—As these spicules had lain for some years in bal- 
sam, which is known to dissolve calcite, I expected to find etch-figures 
which, from the slow rate at which they would have been produced, 
should be neatly developed. Under a Zeiss D, and Ocular No. 4, 
they were easily found on both acerate and sagittal spicules. On 
the former they exist as parallel striz, inclined at an apparently 
somewhat variable angle, often of 60° to 75°. The striz frequently 
occur in groups, which terminate in many cases in a ledge trans- 
verse to them, making with them sometimes an apparent angle of 


In all probability this sponge is Lewconia glomerosa (Bwk.), P, Z.8., 1878, pt. iv., 
figs. 1 to 6, 


Sortas—On Sponge Spicules. 385 


about 60° to 75°, and sometimes of about 96° (Pl. XV., figs. 5 and 7). 
In some cases near the sharp ends of the spicules, which have been 
eroded to a greater depth than the thicker central part, we find 
projecting angles of evident crystals. These angles, which are of 
faces and not quoins, measure usually from 64° to 77° as projected 
by camera lucida on a plane surface (pl. xv., figs. 1 and 2). 

The sagittal spicules display a curious difference in the distri- 
bution of erosion, interesting as showing the influence of crystalline 
structure on solution; their basal, or paired rays, are always well 
etched with strize, and sometimes show as well a fringe of projecting 
angles on the distal or both margins (pl. xv., fig. 3). The un- 
paired ray, on the contrary, is never visibly eroded; it appears to 
enjoy complete immunity from the solvent power of balsam. 

Wishing to develop etch-figures at will, I experimented first 
with Grantia, but found its spicules were too minute to give satis- 
factory results. I then managed to extract from under the cover- 
glass of my mounted specimen of Leuconia glomerosa (?) a bundle 
of colossal acerates; after washing the balsam away with ether 
they were placed in dilute acetic acid, and the process of solution 
watched under a Zeiss D. Strize were soon developed similar to those 
produced by the balsam ; the groups of strize being margined by one 
of themselves, strongly developed, and truncated by a ledge which 
sometimes made an angle of about 77° with them, the acute angle 
of a face of a rhombohedron; in some cases three ridges were 
produced, giving a triradiate figure with angles of about 108°, 
125°, and 127°: such a figure would be produced by the edges of 
a rhombohedron placed similar to that shown in the projection, fig. 7, 
p. 388, where the corresponding angles are 104°, 116°, and 140°. 
The large difference in these angles and those just noted is partly 
to be accounted for by a slight difference in the position of the 
two rhombohedrons, and partly by the difficulty of obtaining exact 
measurements of angles determined by such extremely short lines 
as those of the etch-figures. Partly, also, the plane on which the 
figures were projected by the camera lucida would not be exactly 
at right angles to the reflected rays of light, and some distortion is 
inevitable. It is clear, however, that the etch striz are the edges 
of rhombohedrons, of each of which four faces, lying in a zone, are 
elongated to such an extent as to convert the rhombohedron into 
a prismatic fibre. On one side of an edge, exposed as an etch 


386 Scientific Proceedings, Royal Dublin Society. 


stria, a transverse ridge corresponding to another edge of the 
rhombohedron would make an apparent angle of about 96°, and, 
on the other, another transverse ridge of 60° to 75°, as observed. 

In the projection shown in fig. 7, p. 388, the edges correspond- 
ing to the truncating strize make apparent angles of 94° and 40° 
with the edge which furnishes most of the striee. 

As the solution of the spicule under observation continued, a 
beautifully defined hollow rhombohedron made its appearance 
(pl. xv., fig. 11), and traces of others were seen. Finally, the 
spicule broke up into segments; but I was unable to determine 
whether these were bounded by cleavage planes. 

Cleavage.—The spicules of calcisponges usually break with a — 
conchoidal fracture; but it seemed possible that traces of cleavage 
might be obtained by heating the spicules to short of redness, and 
then plunging into water. This was tried with the coronal acerates 
of Grantia ciliata. 

After igniting, the spicules are perfectly white and opaque, 
as seen by reflected light; mounted in glycerine, they become 
transparent, are brown in colour, and finely granular in texture. 
The edges of the spicules are broken (pl. xv., fig. 8) by straight 
lines, the fractures being apparently those of cleavage; cleavage 
planes frequently traverse the spicule, dividing it into rhomboidal 
fragments, and often it becomes entirely resolved in places into a 
collection of navicula-like bodies (pl. xv., figs 9 and 10), which 
appear to be rhombs with rounded edges. 

Form of Transverse Section.—This experiment enabled me to 
definitely ascertain a fact I had long suspected, but had up to this 
been unable to prove: the acerates of Grantia, as they roll over, 
when seen under the microscope, appear to be greatly flattened 
along two opposite sides, one diameter of a transverse section being 
much longer than the other. So long as the spicules were trans- 
parent I was not sure that this might not be an optical delusion ; 
now that they were opaque, when seen by reflected light, the matter 
could be put to a certain test, as it was, with the result of proving 
that these spicules are in fact, as in appearance, far from cylin- 
drical, being greatly compressed from side to side. The colossal 
acerates are also of oval section, and possibly rhomboidal, the angles 
of the rhomb being rounded off. At all events, one which had 
been etched (pl. xv., fig. 7) showed, after it had broken into 


Sottas— On Sponge Spicules. 387 


fragments, such an outline. That they are not cylindrical may 
easily be proved by rolling them under a cover-glass, and measur- 
ing their diameter in different positions. Their optical double- 
sidedness, due to difference in refractive index, is also then clearly 
seen without the aid of polarized light. 

Heeckel' has recognised the fact that the section of calcareous 
spicules is not always circular, since he says that ‘in the acerates, 
as well as in the triradiates and quadriradiates, the transverse sec- 
tion of the ray is usually circular, seldom elliptical, and much 
seldomer linear, so that the ray is flattened band-like.” He gives 
no instances however. 

Application to the Pharetrones Question.—Since the acerate spi- 
cules of some calcisponges are oval in section, or possibly rhom- 
boidal, this enables us, when other characters are wanting, to 
distinguish such spicules from the similar ones of the siliceous 
sponges; and if the Pharetrones were originally calcareous, their 
colossal spicules should afford us oval and rhomboidal sections; for 
even if the rhomboidal outline observed in the recent spicule were 
due to etching, it is also true that the fossil spicules have suffered 
from the same cause, and so should exhibit similar outlines. On — 
turning to my thin slices of Pharetrones I find that a rounded 
_ polygonal outline frequently characterises the sections of colossal 
spicules; many offer an oval section; and though, of course, a 
cylindrical spicule will give an oval outline if cut obliquely, yet 
in many cases the sides of the ellipse in the fossil spicules are 
far too flattened to be explained in such a manner (pl. xv., 
fig. 12). Though oval and polygonal outlines are common, cir- 
cular ones are not absent; but that does not affect the argument, 
as we do not assert that cylindrical spicules do not occur among calci- 
sponges, but that oval and polygonal ones are not known amongst 
the siliceous sponges.” On turning to the illustrations in my Paper 
on Catagma, I find that I had at that time represented the sections 
of these large spicules as somewhat polygonal, though I did not re- 
cognise the fact at the time, nor if I had should I have understood 
its significance. A distinct polygonal outline is given to the rays 
of many calcisponges in Heeckel’s ‘“‘ Monograph,” v., Taf. 27, &e. 


1 Heckel, ‘‘ Die Kalkschwamme,”’ Band i. p. 208. 
* The shafts of Lithistid skeletal corpuscles are, however, not always circular in 
section. 


388 Scientific Proceedings, Royal Dublin Society. 


These observations furnish a further strong argument in favour 
of the originally calcareous nature of the Pharetrones. 

Orystalline Structure-—We are now provided with observations 
sufficient to investigate more closely the crystalline structure of 
calcareous spicules. 

Commencing with the acerate spicules, we find that in the 
position in which they usually rest the optic axis lies in them 
horizontally, inclined about 70° to their morphological axis, and 
that an axis of maximum elasticity at right angles to the optic 
axis passes through them vertically. 


Fie. 7. 


Diagram showing the position of a primitive rhombohedron, as it would be seen within an 
acerate spicule of a calcisponge, the optic axis being placed horizontally. 4, polar edge; 
d, d, lateral edges of the rhombohedron; oa, optic axis; ss, direction of strize produced 
by etching: they are parallel to the edges which lie in a zone with 6. 


Without spending time in discussing the various positions in 
which a primitive rhombohedron may be placed in order to satisfy 
these conditions, let us proceed at once to describe its actual rela- 
tions to the spicule as deduced from a consideration of the whole 
of the evidence. A primitive rhombohedron lies within the spicule, 
so that one lateral solid angle is lowermost, and four parallel edges 
are inclined at an angle of about 56° with the edge of the spicule 
as seen through the microscope. These edges are those which give 
rise to the parallel striz of the etch-figures; four other parallel 
edges make an angle of 22° with the spicule edge, and the remain- 
ing four parallel edges similarly make an angle of 46°. It is the 
last two groups of edges which give rise to the transverse striz of 
the etch-figures. ; 


Sortas—On Sponge Spicules. 389 


The angle of extinction for the spicule will be about 20° (17° 
in the projection, figure 7), and for the strice a like amount. 

It is obvious that if the rhombohedron occupy this position, one 
will, on rolling the spicule under a cover-glass, alter the observed 
index of refraction and the angle of extinction. 

The reason that any approach to constancy in these elements 
is discoverable in the spicules, as they chance to lie on the micro- 
scope slide, is due to their bow-shaped form and lateral compression, 
so that they rest most readily on one side; and the fact that, under 
these circumstances, a close approximation to constancy occurs, 
shows that the crystalline structure of the spicule is related in a 
more or less constant manner to its form. 

On rolling the acerate spicules of Grantia and those of Leu- 
conia glomerosa (?) under a cover-glass, the expected changes 
were observed; the refractive index varying from about its mini- 
mum to about its maximum value for the extraordinary rays, 
and the angle of extinction from 0° to 44°. In some positions 
the colossal spicules gave a refractive index similar to that of 
the sagittal triradiates, ¢. e. they vanished in balsam; the strice 
should then extinguish at 0°, and make an angle of 75° with 
the edge of the spicule, which should consequently extinguish 
at 15°. These conditions were found on measurement to be rigor- 
ously fulfilled. 

We may fairly conclude, then, that the acerate spicules of those 
calcispongize examined are built up of excessively elongated pri- 
mitive rhombohedrons of calcite, which le with the optic axis in- 
clined at about 75° to the morphological axis of the spicule. 

That this result holds good not only in spicules which have 
been treated with acid, but in unaltered spicules taken from 
spirit specimens (and we may infer in living examples), is shown 
by the similar behaviour of both when examined with polarized 
light. 

The position of the rhombohedron relative to the surface of the 
spicules is very similar to that which may be observed in rhombo- 
hedra of calcite filling up a cavity within a limestone rock, or 
inside the chamber of an ammonite; and we may suppose that the 
deposition of calcite within the spicule sheath occurred according 
to just the same laws as those which are followed in the purely 
mineral world; the first formed layer of minute rhombohedra 


390 Scientific Proceedings, Royal Dublin Society. 


would govern the position of the crystalline axes of all the rest, 
and as growth took place by apposition, all subsequently deposited 
rhombohedra would be arranged in perfect conformity with those 
which served as a foundation; and should the spicules after the 
death of the sponge serve as nuclei on which a further calcitic de- 
posit was laid down, the crystals of this would be governed in their 
arrangement by that already existing in the spicules.1 Hence, in 
fossil Pharetrones we should expect to find just the same optical 
characters as those observed in the recent calcispongie. 


Foraminifera.—Dr. Sorby’ states that from the nature of the 
case he was unable to determine the specific gravity of Foramini- 
fera; but with true insight he inferred that they consist of calcite 
and not of aragonite. Dr. Sorby, no doubt, had in mind the 
Perforate group of foraminifera; and I find by my method of using 
Sonstadt’s solution under the microscope, that these have a specific 
gravity of from 2626 to 2°674. The forms I examined comprised 
Globigerina, Textularia, Rotalia, Discorbina, Nodosaria, Nonionina, 
and Lagena. ‘They could be clearly seen under the microscope 
floating free from air and other impurities in the Sonstadt solu- 
tion, so that had it been desired I could have taken the specific 
gravity of any single one. I also obtained the specific gravity of 
Polytrema; it is the same as that of quartz (2°65). In the ma- 
jority of the Perforate foraminifera the specific gravity is from 
2°65 to 2°674; they evidently consist of calcite, and the difference 
in specific gravity may be attributed to the presence of organic 
matter, of which it would require 3°3 per cent. at a specific gravity 
of 1:5, to reduce the specific gravity of the foraminiferal test from 
27 to 2°66. The Imperforate foraminifera are denser than the 
Perforate forms. J examined Milliola, Peneroplis, Spirolina, and 
Orbiculina. Their specific gravity ranged from 2°7 to 2°722; and 
as they contain a large quantity of organic matter, easily seen as a 
thin film when the mineral matter is dissolved away with acids, the 
specific gravity of the mineral part of their tests must be higher 


1 This prediction has since been unexpectedly verified. Some calcareous spicules, left 
to stand in water containing carbonate of lime, have become overgrown with crystals of 
calcite, arranged in accordance with the crystalline structure of the spicule, as ascertained 
above. 

2 Sorby, ‘‘ Presidential Address on Limestone,’’ Quart. Jour. Geol. Soc., 1879. 


Sortas—On Sponge Spicules. 391 


than that of calcite. Hither it consists of aragonite, or, if of 
calcite, some other substance must be present in addition, possibly 
iron carbonate or phosphate of lime. It would require 12-5 per 
cent. of organic matter to reduce the specific gravity of this forami- 
nifera from 2-9 (that of aragonite) to 2-725, and 14°87 per cent. to 
2°7, the specific gravity which most of them possess. . 

Although sufficiently common in the tertiary rocks, Imper- 
forate foraminifera are much rarer than the Perforate in older 
deposits, and this comparative rarity would be consistent with 
an aragonite constitution for their tests. 

Dr. Carpenter’ states that the shells of the Imperforata have 
no structure of any kind. I find, however, that the shell of 
Milliola, when viewed mounted in turpentine with transmitted 
light, has a very finely granular structure, minute granules lying 
thickly and evenly scattered in the transparent amber matrix. 


NOTE ADDED IN THE PRESS. 


In order to make quite sure that the outline of the transverse 
section of the acerate spicules in some species of calcareous sponges 
is otherwise than circular, I prepared thin slices of entire specimens of a 
species of Grantia from Vancouver’s Land (Grantia coronata?) by cutting 
in frozen jelly. ‘The illustration (pl. xv., fig. 13) shows a section 
through the “neck” of the sponge ; the coronal spicules are arranged 
in concentric circular rows (arcs of nine rows out of sixteen visible are 
represented in the figure), and the transverse section of each is an 
ellipse with flattened sides, or an oblong with rounded ends. Certain 
larger acerates of the radial tubes (pl. xv., fig. 14) offer polygonal out- 
lines, like those of the Pharetrones (pl. xv., fig. 12). These sections ob- 
tained from spicules, unaltered in any way by treatment, dispose of all 
doubt as to their form ; and since the acerate spicules of three species of 
Calcispongiz, all that I have examined, give similar results, it would 
appear that a circular outline is much less common among the acerateg 
of this group than has been hitherto supposed. It would appear that 
the form is influenced by the mineral composition, and if so, one might 
expect calcareous spicules to rarely exhibit quite circular outlines: 
other duties, however, prevent my extending my observations in this 
direction. 


: Carpenter, Introduction to the Study of the Foraminifera, p. 44. 


392 Scientific Proceedings, Royal Dublin Society. 


DESCRIPTION OF PLATE XV. 


Fig. 1.—Colossal acerate spicule of Lewconia glomerosa (2) (Bwk.), showing faces of 
rhombohedra, revealed by erosion ; from a portion near the point. 

Fig. 2.—Similar, showing the eroded pointed end of the spicule. 

Fig. 3.—Two sagittal spicules from the same sponge, showing the eroded paired 
rays, which are both striated and margined by rhombohedral faces; and the unpaired 
ray which presents no signs of erosion. 

Fig. 4.—Part of an eroded acerate, showing strie on one side, and rhombohedral 
angles on the other. On one of these angles a rhombohedron has been indicated by 
dotted lines, to show the relation of the striz and the angles, and the probable position 
of the rhombohedron relative to the spicule. The apical angles of the rhombohedron 
have been joimed by a dotted line, 0 a, which, prolonged in both directions, indicates 
the position of the optic axis. This makes an angle of about 72° with the edge of the 
spicule, which should therefore extinguish at 20°. The strize make an angle of about 
65°, and should extinguish at 7°. This approximates to an observation made, where the 
strize made an angle of 66° with the edge of the spicule, which extinguished at 16°, the 
strie at 9°. 

Fig. 5.—Part of a colossal acerate, showing etch strie. 

Fig. 6. ihren se section of a colossal acerate, which had been slightly etched = 
acetic acid. 

Fig. 7.—A group of etch strie. 

Figs. 8 and 8a.—Two of the coronal acerates of Grantia ciliata, after heating nearly 
to redness, showing broken edges, bounded by cleavage planes. 

Fig. 9.—Similar, showing the navicula-like bodies into which the spicule breaks up. 

Fig. 10.—A single one of these rhombs. 


Fig. 11.—A colossal acerate, after etching with acetic acid, showing groups of stric, 
and on the right-hand edge below three sides of a rhombohedral pit. On the right-hand 
side above is a trivadiate marking, corresponding to the edges 0, d, and d@’ in the projec- 
tion, fig. 7, woodcut, p. 388. 

Fig. 12.—Outlines of transverse sections of shafts of colossal spicules in a Phare- 
trone (Catagina porcatum). 

Fig. 13.—Part of transverse section through the ‘neck’ of Grantia sp. from Van- 
couver, N. America, showing ares of nine out of sixteen circular rows of acerate spicules 
visible in the preparation. 

Fig. 14.—Transverse sections through large acerate spicules of the same sponge. 

Fig. 15.—Transverse sections of acerate spicules shown in fig. 13 more highly mag- 
nified: (a) sections at right angles to the lines of sight; (6) slightly inclined, showing 
the side of the spicule, indicated by shading. 

All figures drawn by Camera lucida, figs. 1 to 12 under; Zeiss D, Oc. No. 4; figs. 
13 and 14, Zeiss D, Oc. No. 2; fig. 15, Zeiss H, Oc. No. 3. 


XLVITI.—ON THE NEWLY DISCOVERED SAPPHIRE MINES 
IN THE HIMALAYAS. By V. BALL, M.A., F.B.S., 


Director, Science and Art Museum. 
[ Read, February 16, 1885. ] 


A very remarkable, and so far as is known, new discovery of a 
mine of sapphires, rubies, and ordinary corundum was made about 
the years 1879 and 1880, in the district of Paldar, or Padar, north 
of the Chandrabagha Range, but south of the main chain of the 
Himalayas. The district of Zanskar—whence they were incorrectly 
supposed to come by some writers—lies to the north of the chain. 

The stones were found at the foot of a precipice, where a land- 
ship had taken place. ‘The including rocks are gneiss and mica 
schist. At first the stones were merely collected by the villagers, 
who were attracted by their beautiful colours; but so little was 
their value realized, that they were used as flints are for striking 
lights with steel. At that time they appear to have been so 
abundant that one writer speaks of having seen about one cwt. of 
them in the possession of a native. Gradually, as they were car- 
ried by traders to distant points, especially to Simla, their value 
became known, and the agents of jewellers commenced a brisk 
competition, till most of the available stones had been bought up. 
The Maharajah of Cashmere then intervened by sending a regi- 
ment of sepoys, with their officers, to take possession of the mines; 
and, it would appear, with carte blanche to harry the inhabitants 
who had, or who were suspected of having, any of the stones in 
their possession. Indeed, so thoroughly did they fulfil their mis- 
sion, that any one they laid hands upon who was found to have 
money, was suspected of either having sold or being about to pur- 
chase sapphires, was thereupon despoiled, and if not arrested and 
confined, was placed under observation. 


1 The principal authorities on the subject are—Mallet, Rec. Geol. Sury., India, 
vol. xv., 1882, p. 138; S. B. L., Civil and Military Gazette, Lahore, Nov. 2, 1888 ; 
Shepard, C. V., Am. Jour. Sci. (vol. xxvi., No. 155), Nov. 1883, p. 839; Ly- 
dekker, R., Mem. Geol. Surv. India, vol. xxii., p. 335. 


SCIEN. PROC. R.D.S.—VOL. IV. PT. VII. 21 


394 Scientific Proceedings, Royal Dublin Society. 


The effect, as described by the few Europeans, principally mis- 
sionaries,' who live in the country, has been to cause those who 
knew, or thought they knew, other localities where similar stones 
were to be found to remain silent, and to conceal evidence of their 
knowledge so as to escape oppression. 

Many of the specimens which have been examined are well- 
formed double hexagonal pyramids; their surfaces are often much 
covered with small crystals of tourmaline, which also penetrate the 
mass. A thin coating of a white mineral, supposed to be gibbsite, 
occurs on some of the specimens; and chlorite also occurs with the 
sapphires, besides other varieties of corundum and magnetite. 
Since corundum in various forms is a known product of many 
parts of the peninsula of India, and is mined for, and has a com- 
mercial value with the natives,” it is not improbable that sapphires 
have been occasionally met with; one, for instance, which is men- 
tioned in books on precious stones as “the wooden-spoon seller’s 
sapphire,” is said to have been found in Bengal; but I have been 
unable to find any definite record of a sapphire mine in that 
country. Like other jewels, sapphires have been always abundant 
in the Indian marts since the earliest times, when they were known 
to Europeans as hyacinths, a name derived from the Arabic and 
Persian yacut. The term was also applied to a variety of garnet ; 
but the evidence distinctly points to their having been imported 
from Ceylon, and to a small extent from Burmah. It is note- 
worthy, as regards the latter country, that sapphires occur as 
sparingly in the Kyatpen (often incorrectly written Capellan) ruby 
mines as rubies do in the Cingalese sapphire mines. 

The above abstract of information regarding these mines was 
prepared some time ago, and it is now communicated to the Society 
in consequence of a recent acquisition by the Museum of one fine 
specimen, and some smaller fragments. They were brought to Mr. 
Moss by a gentleman, who informed him that they were a remnant 
of a large quantity purchased from a native, who came from a 
locality situated about 150 miles north of Simla. The locality 
mentioned above is much further away; but the discrepancy is of 


' Rev. A. W. Heyde, Rev. M. B. Carleton, W. Graham, formerly of Kulu, and a 
writer in the Lahore paper, signing himself S. B. L. 

* Iwas recently told by Dr. Isaac Lea, of Philadelphia, that some considerable 
shipments of Indian corundum had been received there. 


Batt—On the Sapphire Mines in the Himalayas. 099 


no importance, as there was no pretension of exact accuracy in the 
statement. We may safely conclude, I think, that the specimen 
now exhibited is from Paldar. It is a slightly distorted double 
hexagonal pyramid, weighing 126-425 grammes, and measuring 
2°26 in. in length, by 1:8 in maximum breadth; the sp. g. 1s 3°98. 
Before the apices of the pyramids were broken off it may have 
been longer. In colour it is somewhat mottled, the blue being 
irregularly suffused through the greyish white of the bulk of the 
stone. Where broken it presents a somewhat opalescent appear- 
ance, and this indeed, it is stated, was the cause of its mutilation, 
as its former possessor was told by some one that if he broke it he 
would find opal inside. Fortunately the ignorant advice so offered 
was only partially acted upon, and this interesting specimen will be 
preserved in our mineralogical collection. It is certain that, even 
if it does not contain portions of perfect and uniform colour, it is 
still such a stone as the astute jewellers of Ceylon would value for 
cutting. I have several stones cut by these adepts, which when 
looked at in their setting, present a very good colour, owing to the 
ingenious way in which the blue portion of an otherwise colourless 
stone has been manipulated so as to form a back. 


L2 


[ 396 | 


XLIX.—A NEW SPECIES OF HALCAMPA (H. ANDRESII) 
FROM MALAHIDE. By ALFRED C. HADDON, M.A., 
F.Z.S., Professor of Zoology, Royal College of Science, 
Dublin. (Prate XVI.) 


[ Read, November 17, 1884. ] 


Maleampa andresii (sp. nov.). 
DESCRIPTION. 


Form.—Column divided into capitulum, scapus, and physa. 
Capitulum and scapus slightly corrugated. Physa a distinct 
rounded bladder, may become flaccid, but is non-retractile, with 
numerous suckers. Tentacles 12, marginal, monocyclic, cylin- 
drical, obtuse, slightly arched upwards, about as long as the 
diameter of the disc. Disc round and flat, central portion often 
elevated into a truncated cone. Mouth linear. 


Colour. —Capitulum pale burnt-sienna colour, with a pair 
of sulphur-coloured bracket-shaped () marks in the inter-radii. 
Scapus translucent, through the walls of which the generative 
organs (?) shine with a creamy orange colour. Physa transparent 
white, with opaque white suckers. Throughout the whole length 
of the column the insertions of the mesenteries appear as white 
lines. Tentacles of same colour as capitulum, but more trans- 
parent, with four madder-brown rings on the internal aspect, of 
which the two lower are usually V-shaped; on the outer aspect 
of the base of each tentacle is a pair of slightly diverging brown 
lines. Disc of same colour as tentacles, with 12 inter-radial 
sulphur-coloured lines, extending from the mouth to near the 
base of the tentacles where they become brown in colour; near 
the base of each tentacle is an imperfect madder-brown oval 
ring, bounded externally by a sulphur-coloured streak; there is 


a second similar streak below the lowermost tentacular ring. 
Mouth pale orange. 


Happon--A New Species of Halcampa. 397 


Dimensions.—Length about 20 mm.; diameter about 4:5 mm. 
Habitat.—In sand, at Malahide, county Dublin, at low water. 


This is the first recorded example of this genus in Ireland; it 
was found on the shore at Malahide at low water by my friend 
and former pupil, Miss A. Shannon, on September 13, 1883. 

Like the other species of the genus, this form usually lies 
buried in the sand; when free, it often adheres by its posterior 
extremity, standing upright in the water, or it may lie prostrate, 
adhering by some of the small wart-like suckers of its physa. 

I give myself the pleasure of naming this species after my 
learned and laborious friend, Dr. A. Andres, Professor of Zoology 
at Milan, to whom all zoologists are indebted for his most admir- 
able Monograph on the Actinie. 

The type specimen is deposited in the Natural History Museum, 
Science and Art Department, Dublin. 

Two species of Haleampa have been previously recorded as 
British, viz. H. chrysanthellum (Peach), and H. microps (Gosse) ; 
the former from Cornwall, and the latter from South Devon. 
The name of the first species stands; but, as Andres has shown 
in his Monograph of the Actiniz,’ H. microps, possessing as it 
does sixteen tentacles, is undoubtedly an Kdwardsia, and therefore 
does not concern us at present. 


ANALYSIS OF THE BritisH Spectres oF HAaLcAMPa., 


Tentacles with six white half-rings. Disc bluish in centre, 
brown towards periphery, with pale inter-radial lines, which are 
trifid towards the base of the tentacles.—H. chrysanthellum 
(Peach).’ | 

Tentacles with four brown half-rings. Dise uniform; buff, 
with yellow inter-radial lines, and an oval brown ring at the 
base of each tentacle.—Z. andresii (sp. n.). 

Dr. W. Keferstein described, in June, 1862,° two kinds of 


1 Fauna und Flora des Golfes von Neapel, IX. Die Actinien, 1884. 2 
2 Of. Actinologia Britannica, a History of the British Sea-anemones and Corals, 
1860, p. 247. 
3 Zeitschrift fiir wissenschaftliche Zoologie, XII. (1863), pp. 31-34, Pl. II. 
figs. 15-22, 


398 Scientific Proceedings, Royal Dublin Society. 


Halcampa from St. Vaast la Hougue, Manche (North France), 
which he named Xanthiopus bilateralis and X. vittatus, gen. et 
sp. nov. Andres considers these as varieties of one species, which 
he re-names Halcampa kefersteim, var. a. vittata, and var. (3. bilate- 
ralis (4. ¢., p. 102). 

Keferstein’s description is very meagre, and his figures imper- 
fect; but there can be no doubt that the French species is distinet 
from the Irish. 


EXPLANATION OF PLATE XVI. 


WMaleampa andresii (sp. nov.). 


Fig. 1.—Side view of animal x 3 diam. 


,, 2.—Side view of dise and mouth, showing the tentacles in their 
ordinary position x 4 diam. about. 


» &.—View of disc and tentacles from above x 4 diam. about. 


,, 4.—Side view of external aspect of tentacles x 4 diam. about. 


( 399 ) 


L.—THE STRUCTURE AND HABITS OF PEACHIA HAS- 
TATA (GOSSE), Parr I. By ALFRED C. HADDON, 
M. A., Professor of Zoology, Royal College of Science; and 
GHO. Y. DIXON, M.A. (Puates XVI., XVII., and XVIII.) 


(Read, December 15, 1884.) 


Peachia hastata (Gosse). 


Actima cylindrica, 


Peachia hastata, 


Stphonactinia, 


HIsTorRIcat. 


Reid, 1848, Ann. Mag. Nat. Hist., n.s., 1., 
p. 34, Pl. (non Renier). 

Gosse, 1855, Trans. Linn. Soc., xxi., p. 267, 
Pl. XXVIII. 

Gosse, 1855, Man. Marine Zool., 1., p. 81, 
fie. 46. 

Milne-Kdwards, 1857, Hist. Nat. des Coral- 
liatres, 1., p. 287. 

Gosse, 1858, Ann. Mag. Nat. Hist., ser. 8, 
1., p. 418. 

Holdsworth, 1859, Ann. Mag. Nat. Hist., 
ser. 3, l., p. 78. 

Gosse, 1860, Actinologia Britannica, p. 235, 
Pl. VIII., fig. 3, and woodcut. 

Hincks, 1861, Ann. Mag. Nat. Hist., ser. 3, 
Vil., p. 363. 

Dana, 1872, Corals and Coral Islands, p. 25 
and p. 26, fig. 1. 

M‘Intosh, 1874, Ann. Mag. Nat. Hist., ser. 4, 
Xili., p. 220, 

Faurot, 1884, Comptes rendus, xevili. No. 
12, p. 756. 

Andres, 1884, Die Actinien, Fauna u. F1., 
d. Golfes, v. Neapel, ix., p. 110. 


Tuts remarkable species has hitherto only been recorded from 
Torbay (8S. Devon), “at extreme low water, and thence down- 
wards, buried in sand”—Gosse; from St. Andrew’s Bay (Fife) — 
Reid; ‘thrown ashore on the West Sands after storms in great 


400 Scientific Proceedings, Royal Dublin Society. 


numbers. It occurs also in the stomach of the cod”—M‘In- 
tosh; and from Roscoff (Cétes du Nord, N. France)—Faurot. 
We now extend its range to Dollymount, Dublin Bay, and from 
information received from Miss Shannon, it is probable that it 
also occurs at Larne, county Antrim; it therefore is distributed 
over the British Isles, and to the north of France. ‘The peculiar 
habits of this form have probably been the reason why it has not 
been met with elsewhere, and more often. 

Mr. Gosse, on p. 245 of the Actinologia, says of the Actinia 
cylindrica, described by Reid :—‘“ It must have certainly been a 
Peachia, and may possibly have been an immature P. hastata.” 
Gosse states three points in which it disagreed from his species :— 
(1) It was but one and a quarter inch long.” This objection 
amounts to nothing. ‘“(2) The conchular lobes were tielve, six of 
which were very minute, triangular, orange, with translucent edges.” 
As will be seen from our account, the conchular papille are sub- 
ject to great variation in number, size, and colour. “ (3) Twelve 
bands of faint reddish-brown radiated across the disk.” From 
this it would appear that Dr. Reid’s specimen was sickly, having 
been “thrown on shore by a storm,” and that it never properly 
expanded, consequently the dise would not be seen. The tumid 
striped cesophagus of this form is so large and so frequently pro- 
truded, and especially when the animal is dying, that there can 
be little doubt that it was in this instance mistaken for the dise. 
Thus none of Gosse’s objections stand. Reid describes “the upper 
three-fourths of the body to be opaque and of a pale pink colour.” 
In one of our specimens the column, excluding the physa, was of 
an opaque flesh-colour, with only one or two fine reddish-brown 
stripes or spots. 

The identity of these two species is admitted by Dr. W. C. 
M‘Intosh, who after recording it from St. Andrews, states (/. ¢., 
p- 220) it “was thus first found in Britain by Dr. John Reid, of 
St. Andrews, who published a description of his single example in 
1848 (Physiological, Anat., and Pathol. Observations, p. 656, 
pl. 5, f. 21 and 22); his title (4. cylindrica) has, therefore, a prior 
claim to that of Mr. Gosse.” 

We have entered thus fully into a discussion on Reid’s species, 
as it is more satisfactory to clear up the older species than to leave 
them as dubie. Although ourselves convinced of the identity of 


Happon anp Dixon—The Structure of Peachia hastata. 401 


the two species in question, we do not propose to alter the specific 
name which is in general use, as the name Actinia cylindrica was 
pre-occupied by Renier in 1804 (Prodromo di osservazioni sopra 
alcuni animali, p. 23), and though not now retained in use, being 
synonymous with Cerianthus membranaceous, Spallanzani, 1784, 
this priority is sufficient to prevent the adoption of Reid’s specific 
name. Furthermore, Reid’s description and figures are meagre 
and unsatisfactory, whereas Gosse’s account and drawings are 
sufficiently lucid to enable one to readily identify the animal. 

There is no doubt that Gogse has priority in the generic name, 
therefore we cannot follow Andres in calling it Stphonactinia 
hastata.' 


DESCRIPTION. 


Form.—Column only divided into capitulum, scapus, and physa, 
when fully distended. When contracted the column is rugose, but 
smooth when fully distended ; it is furnished with numerous minute 
suckers. ‘I'he physa is very variable in size and completely retrac- 
tile. Tentacles, twelve marginal, monocyclic, cylindrical, obtuse ; 
when the animal is free they are usually carried more or less bent 
forwards; when in its burrow, they lie at about right angles to 
its length. Disc round, narrow, flat. Mouth large, but usually 
masked by the conchula. Conchula (the free oval extremity of the 
siphonoglyphe) varies greatly in complexity, having from six to 
twenty lobes; one basal and two lateral lobes may always be 
detected, which are larger and carry more secondary lobes than 
the remainder. The basal lobe forms a kind of lid or opercu- 
lum to the siphonoglyphe. 

Colowr. — Capitulum translucent, the ‘oesophagus shining 
through with a purplish colour. When the animal is in its 
burrow the contracted capitulum has a corrugated greyish appear-- 
ance. When the tentacles are completely contracted, radiating white 
linear spots are plainly seen on the capitulum; the fundamental 
number is twelve, but there is a tendency for them to become 


1 Peachia, Gosse, 1855, Trans. Linn. Soc., xxi. p. 267; Siphonactinia, Danielssen 
and Koren, 1856, Fauna litt. Norvegix, il., p. 87; of. Ann. Mag. Nat. Hist. (2), 
xx. 1857, p. 240. : 


402 Scientific Proceedings, Royal Dublin Society. 


more numerous. Scapus, opaque when contracted, translucent 
when fully distended; flesh- or almost salmon-colour, sometimes 
very sparsely, usually considerably splashed with reddish-brown 
in irregular longitudinal lines, often interrupted, and ending in 
streaks ; some specimens incline to brownish tinge, others chestnut, 
and some are pinkish. Physa, translucent when expanded, tinted 
with the ground colour of the scapus. Throughout the whole 
column the insertions of the mesenteries appear as white lines, 
which are, however, indistinguishable in the contracted scapus ; 
posteriorly their number is increased by the occurrence of inter- 
mediate ones. Tentacles translucent, pinkish, or very pale purplish- 
brown; at the base is a white W mark; above this a white equi- 
limbed cross, of which the arms are curved upwards. ‘The space be- 
tween these two markings is filled up with dark-brown; above are 
two white W marks, and frequently a third, but more faint and 
imperfect. The lateral bays of these W marks are occupied by a 
brown stripe, and are the only apparent markings under certain 
aspects of the tentacles—sometimes a whitish streak may be detected 
near the tip. The back of each tentacle bears an opaque white 
spot about half way between the base and the tip. Disc pinkish, 
with white inter-radial lines; in the radu, at the lips of the mouth, 
is a white spot; above that a triangular brown spot; outside this 
a white A mark, and between this and the W at the base of the 
tentacles is a brown ){, or hour-glass mark. Inside of cesophagus, 
marked with twelve dark-brown bands, alternated with broader 
orange-bufi bands; deeper down the colour is reddish or purple. 
Conchula flesh-coloured, or pale pink; aperture appears black; 
lobes with a brown or dark-red core, usually with a white apical 
spot, which may be prolonged into a white line, which appears to 
connect the papillee with one another. 

The markings on the disk and tentacles vary greatly in form 
and intensity, according to the degree to which the animal may be 
distended. 

Dimensions.—Length, 1 to 4 inches (25 to 100 mm.) when 
contracted; may reach 8 inches (205 mm.) when fully distended ; 
diameter about 4-inch (12 mm.) whether contracted or distended. 

Habitat.—In sand at extreme low water, and at shallow depths. 
Localities, N. France, 8. England, HE. Ireland, and EH. Scotland. 

The appearance of the conchula has not been described by 


Happon anp Drxon—The Structure of Peachia hastata. 408 


Gosse with sufficient minuteness, we therefore deem it advisable to 
add a few words on the subject. The anatomical relations of this 
organ we reserve for our second communication ; suffice it now to 
state that it is situated at one extremity of the mouth, and that it 
is manifestly formed by two folds uniting with each other, the line 
of junction being towards the mouth, and opposite the side we term 
the base. The free edge of the tube thus formed is prolonged into 
a number of processes—from six to twenty. The simplest state we 
have seen is that shown in Pl. XVL., fig. 5, where there are six 
nearly equal lobes—in all other specimens the basal and both ter- 
minal lateral lobes are larger and more complex than the others. 
They, and more especially the two latter, may give rise to several 
secondary processes, till the organ attains a very complicated ap- 
pearance. It appears to us not improbable that there are but 
really three primary lobes, and that the varying number of pro- 
cesses may be but complications of the same. As has been already 
noted above, there is a dark central core; a white streak may 
usually be traced running from one papilla to another, and termi- 
nating at the apex of each. This organ is very extensile, and 
admits varied movements both as a whole and in its parts. 

The observation of the physa im living specimens is rendered 
very difficult by its being almost always more or less introverted. 

When it is fully distended a number of apparent perforations 
may be seen ranged in linear series along the radii, they do not 
extend to the scapus; no posterior pore appears to be present 
during full distension. 

When in a state of partial distension the introverted base 
appears perforated; but this may be an optical delusion, as may 
also the above-mentioned thin spots, which are slit-like, or round, 
according tothe amount of distension of the physa. (Pl. XVIIL., 
figs. 3 and 4). 


Hapsirts. 


~ Peachia hastata makes for itself a burrow in the sand eight 
or nine inches deep. Sometimes it extends itself perpendicularly 
from this hole to a height of three or four inches, but usually it 
spreads its tentacles just over the surface of the sand, and it may 
often be seen with its tentacles withdrawn while the conchula is 
still protruded level with the top of its hole. When left dry by 


404 Scientific Proceedings, Royal Dublin Society. 


the tide it habitually protrudes its mouth, the purplish cesophagus 
marked with the pale lines being then very conspicuous. Some- 
times when it projects perpendicularly out of the hole it encircles 
itself with a collar about one inch in depth of slime set thickly 
with particles of sand. It rarely projects much except at night, 
generally sinking down if exposed to a strong light. It can make 
a burrow in the sand with considerable ease. Mr. Holdsworth has 
made an interesting observation on this process :—‘“‘ After it had 
selected a suitable place for burrowing, in the darkest part of the 
vase, the posterior extremity became tapered to a fine point by a 
partial expulsion of the contained water, and at the same time 
turned downwards and pressed slightly into the ground; the fluid 
contents of the animal were then forced back until the base was 
completely distended, and by this means a shallow depression in 
the sand produced; the tail then resumed its conical shape, was 
again thrust into the ground, and swelled out; and these proceed- 
ings were continued until a hole was made sufficiently large to 
admit the animal. Its first efforts in burrowing had but little 
effect, and it was only after an hour’s labour, when the cavity 
had become large enough to allow the polype to work in an up- 
right position, and with the assistance of its whole weight, that 
rapid progress was made.”! (See Pl. XVIII, fig. 7.) 

This anemone can swallow a good-sized piece of food if it is 
placed on its disc. It opens its mouth slowly to the size required, 
and as soon as the lip grasps the food all round, it suddenly closes 
in upon it, swallowing down the food with more ease and rapidity 
than most other anemones, and often without the aid of its ten- 
tacles at all. In a few hours afterwards the digested food is 
vomited up by the mouth; but this is not the only mode of 
getting rid of its food after digestion which P. hastata possesses, 
as small portions of excrement, moulded apparently by passing 
through the tube, are often ejected through the conchula. When 
the animal is irritated, or contracts itself suddenly, three or four 
such pieces are sometimes ejected; but otherwise they come up at 
intervals, and generally a day or two after feeding. ‘The conchula 
is often covered with a glairy slime which it seems to exude. 

The tentacles are capable of a great amount of individual 


1 Holdsworth, Annals, N. H., for Jan. 1859, p. 78. 


Happon anp Dixon—TZhe Structure of Peachia hastata. 405 


motion; it is not uncommon to see one or two contracted and 
reduced to the size of mere warts, while the rest are fully ex- 
tended and ready to grasp anything that comes within their reach. 
They do not seem to be provided with urticating powers to the 
same extent as the tentacles of other anemones; for shrimps and 
little fish that haunt flat sands brush against, and even rest upon 
them, without suffering any apparent inconvenience. 

In confinement we have found P. hastata lives best without 
having sand to burrow in. They generally lie at the bottom of 
the tank, surrounded more or less with collars of slime interwoven 
with the confervoid growth that gathers in an aquarium ; sometimes 
they hold themselves erect. 

The body wall of P. hastata is studded with minute suckers 
which enable it to hold itself upright against any smooth surface ; 
these suckers never lay hold of particles of sand or shell, as do 
those of Tealia and Heliactis. 

After being some time in confinement, these anemones often 
become ruptured in several places, their craspeda protruding in 
convoluted masses which usually slough off; the animal generally 
remains constricted at the point of rupture, and will live several 
days in this state and may ultimately recover. We have no parti- 
culars to give concerning their method of reproduction. 


For Duscription oF PLATES, see over. 
>) 


406 Scientifie Proceedings, Royal Dublin Society. 


EXPLANATION OF PLATES XVI., XVII, ann XVIII. 


Peachia hastata (Gosse). 
PLATE XVI. 


Fig. 5.—Upper view of conchula with six simple lobes ; same specimen 
psy 21l; OWIDL SS sale, 7, 
6 and 7.—Upper views of more complex conchule. 


)S) 


8.—Side view of a complex conchula. 


99 


[All the above are greatly enlarged and not drawn to scale.| 


PLATE XVII. 


Fig. 1—Side view of animal in an ordinary position ; natural size. 

9.—Diagrammatic view of tentacles and conchula.—G. Y. D. 

3.—Appearance of Peachia hastata in its burrow, looking down 
vertically upon it; magnified. 

4,.—Three tentacles illustrating the different appearances due to 
extension, illumination, &c.; enlarged. 

5.—Details of markings on a single tentacle and radius; enlarged. 


99 


99 
99 


99 


PLATE XVIII. 


Fig. 1.—Animal projecting from the sand, tentacles retracted, promi- 
nent conchula, showing markings on capitulum ; enlarged. 
,, %.—Capitular markings of another specimen ; enlarged. 
,, 3.—Inflated physa, with slit-like spots; greatly magnified. 
,, 4.—A still greater state of distension, with circular spots; greatly 
magnified. 
,, 5 and 6.—Showing variations in form; two specimens; natural size. 


,», %.—HIllustrating the way in which the animal burrows into the sand. 


(aay J 


LI.—ON A MODEL ILLUSTRATING SOME PROPERTIES OF 
THE ETHER. By GEORGE FRANCIS FITZGERALD, M.A., 
F.T.C.D., F.B.S. 


[ Read, January 19, 1885. ] 


Tut model I have constructed consists of a series of wheels, rota- 
ting on axes fixed perpendicularly in a plane board, and connected 
together by indiarubber bands. The axes are fixed at the inter- 
sections of two systems of perpendicular lines, and each wheel is 
connected with each of its four neighbours by an indiarubber band. 
Thus all the wheels can rotate without any consequent straining of 
the system if they all rotate at the same rate. If, however, some 
of the wheels be rotated through a different angle from others, the 
indiarubber bands will be strained. 

If it is desired to represent a region in which conducting mat- 
ter exists, it will be represented by removing the bands from a set 
of wheels. Suppose the bands are removed from the regions a and 
b, and from the connecting line ad, we can represent the charging 
of these regions with opposite electricities by introducing some 
mechanism, by means of which the wheels on opposite sides of the 
line ab can be rotated in opposite directions. And now I desire 
to explain that I do not intend the model to illustrate at all the 
connexion between the ether and the matter, and indeed think it 
one of the advantages to be derived from studying this model that 
it so distinctly emphasizes the distinction between the phenomena, 
depending on the general properties of the ether by itself, and 
those depending on its connexion with matter. For instance, 
from this very case we are considering, we get impressed upon us 
that it is by means of matter only that we can get a hold on the 
ether so as to strain it. As I am not careful to illustrate the con- 
nexion between matter and ether, any rough method of turning 
the wheels so as to create the proper strain, will do well enough, as 
it is not the method of producing but the nature of the strain pro- 
duced that I wish to study. Having once rotated these wheels, 
we may replace the bands along the line a, and we have the 
state of the ether between two oppositely electrified bodies repre- 


408 Scientific Proceedings, Royal Dublin Society. 


sented on the model.. Observe that half the indiarubber bands are 
strained, and that in lines running round the bodies the tight side 
of a band is always away from one body and next the other. 
This represents the polarisation of the ether. Clerk-Maxwell de- 
fines polarisation as a state in which the opposite sides of each 
element are in opposite states. Now the opposite sides of each 
band are in opposite states, one side loose, the other tight; and so 
it can very well represent the polarised state of the ether. The 
displacement producing the polarisation is due to the different 
rotation of the wheels carrying the band causing more of the band 
to be at one side of the wheels than at the other: less at the tight 
and more at the loose side of the pair of wheels, and this represents 
the electric displacement producing the polarisation. The direction 
of this displacement is at right angles to the line of the bands that 
are strained, and is out from one body and in towards the other, 
all round. Now, one of the first things one would expect a model 
of the ether to represent would be the force of attraction between 
these two electrified bodies, and which is not represented on my 
model. ‘This, however, is because this force depends entirely on 
the connexions between the ether and matter; and as I have 
already explained, this connexion is not represented on my model, 
and in consequence of this the attraction depending on this con- 
nexion is quite rightly not represented on my model. I may, how- 
ever, be permitted to suggest a way in which my model might be 
modified so as to represent this force, especially as it will emphasize 
a point about this force that is frequently overlooked in describing 
electrical phenomena. ‘This point is that the force is proportional 
to the square of the electric displacement, and consequently cannot 
be directly and simply due to it, as in ordinary solids forces are 
produced by displacement: for in them the force is proportional to 
the displacement, and not to its square. The result is that the 
sign of the force is independent of the sign of the displacement, 
and is the same whether it be positive and negative, or vice versa. 
This is a very important distinction, and is obvious when pointed 
out, for it is evident that it is electromotive force, and not the 
mechanical force, that depends on electric displacement in the same 
way as mechanical forces depend on displacements of solids. 

Now, if the wheels over which the bands run were made of 
some deformable, not merely incompressible, substance, such as 


FirzgeratD—On a Model Illustrating Properties of Ether. 409 


indiarubber, it is evident that they would be deformed by the 
straining of the bands. Now, if inextensible threads were 
wound round them, and the ends of the threads connected respec- 
tively with the bodies a and 8, it is evident that as the deformation 
of the circular wheels would enlarge their circumferences, these 
threads would tend to draw the two bodies together. Now, the 
shortening of the threads would be proportional to the square of 
the linear deformation of the wheels, and so the resulting force 
might represent the electrostatic attraction of the two bodies. If 
we consider the force that would be thus produced between two 
infinite planes, we see that it would be the same no matter what 
their distance apart so long as the polarisation is kept the same; 
and that consequently it will represent a force varying inversely as 
the square of the distance from a point. I mention this crude 
mechanism in order to show that it is possible to represent by 
mechanism the connexion between the ether and matter, and also 
to illustrate how electrostatic attractions depend entirely on the 
way the ether is connected with matter. 

Let us now return to consider what other properties of the 
ether are represented by the model. Observe, in the first place, 
that during the time polarisation is taking place the wheels are 
rotating, and that the rate of rotation of the wheels is pro- 
portional to the rate of increase of polarisation, and that the 
direction of the axis of rotation is perpendicular to the direc- 
tion of the displacement. We, of course, at once conclude that 
the magnetic force is properly represented by the rate of rota- 
tion of the wheels, and its direction by the axis of rotation. We 
thus see that any change of displacement produces rotation of the 
wheels, 7. e. magnetic force; and we will presently see that what 
represents an electric current is similarly accompanied by rotation 
of the wheels. The momentum of the wheels while rotating repre- 
sents the kinetic energy of the currents producing the magnetic 
force, and in the case of one current is its self-induction. Now, if 
we suppose something to loosen the hold of the bands on the 
wheels, this will represent the presence of some partially conducting 
matter, for evidently perfectly conducting matter must be repre- 
sented by the fact that no amount of difference of rotation of 
neighbouring wheels, 7. e. no amount of electric displacement can 
produce any polarisation, and we have represented it by removing 
2M 


SCIEN. PROC. R.D.S.—VOL. IV. PT. VII 


410 Scientific Proceedings, Royal Dublin Society. 


the bands from the wheels entirely: a conductor offering some 
resistence would be represented by making the bands loose. If 
the bands be not sufficiently tight on the wheels between a and 8, 
they will slip if the polarisation be carried far enough; and if the 
kinetic be much less than the statical friction, the polarisation of 
the medium will suddenly disappear by the slipping of the bands, 
and the energy of the polarisation will be converted into heat along 
the line of slipping. This evidently represents a discharge between 
the two electrified bodies. Now, observe further that, if the resist- 
ance to discharge be very small, the momentum of the wheels will 
carry them beyond their position of complete depolarisation, and a 
series of oscillations will be set up, the polarisation alternating in 
opposite directions; but, of course, ultimately all the energy will 
disappear as heat along the line of discharge. This exactly repre- 
sents the discharge between two electrified bodies. If the resist- 
ance to discharge be small enough, an oscillating discharge is pro- 
duced which, however, ultimately dies away, all its energy being 
spent on heating the wire along which the discharge occurs. Now, 
observe further, the direction in which the energy of the medium 
flows in to the line of discharge. It comes in in the length of the 
indiarubber bands, 7. ec. in a direction at right angles both to the 
electric displacement and to the magnetic force, and it comes in at 
the side of the line of discharge. This is exactly what Professor 
Poynting has lately shown to be the case in the ether. 

Let us now consider the case of a complete conducting circuit 
in which there exists an electromotive force at one place, and 
resistances all round. This can be represented by taking away 
the bands, or making them loose, along a series of wheels in a 
circuit, and arranging mechanism for turning the wheels at one 
part of this circuit, and introducing some friction at all the other 
parts. Suppose our electromotive force is along the line a b, and 
that the resistance is introduced by friction along the outside 
wheels. As I have already explained that I do not intend my 
model to illustrate the action between matter and ether, any crude 
mechanism suffices to represent the .electromotive force. ‘The 
circuit where there are no bands, or loose ones, is our conducting 
circuit, and the friction to the wheels along it is the resistance 
of the circuit. Now, if the wheels be driven at any point of the 
circuit, all the region will be full of wheels turning, for all the 


FirzgERaALp—On a Model Illustrating Properties of Ether. 411 


wheels must turn simultaneously. This rotation of the wheels 
represents the magnetic force, and the motion of the parts of the 
wheels in contact with the circuit being everywhere in the same 
direction round it, represents the electric current. There is no 
transference of anything along the current, and the energy de- 
veloped at any point is transferred to that point, not along the 
current, but in at its side in the direction of the elastic bands per- 
pendicular to the current. Now, this is exactly the state of affairs 
that Professor Poynting showed to exist in an electric current. 
This direction is at right angles to the axis of rotation of the 
wheels, and also to the direction of polarisation of the bands, 7. e. 
to the magnetic and electric displacements. The self-induction of 
this circuit is represented by the momentum of the wheels. It is 
easy to see how the polarisation of the bands is connected with the 
resistance along any length of the circuit. When the resistance is 
great the bands will be greatly polarised, 7. e. the electric displace- 
ment is great, 7. e. the rate of fall of potential will be great; and 
as this will be directly proportional to the resistance, we see that 
the fall of potential along any length of the circuit is proportional 
to the resistance of that section, which is Ohm’s Law. In order 
completely to represent Ohm’s Law, it would be necessary to 
arrange that the friction was proportional to the rate of revolution 
of the wheels. This, however, is trenching on the connexion of 
matter and ether. Another question, similarly circumstanced, is 
the mechanical force exerted on the conductor, due to a mag- 
netic field. It is evident that the direction in which to look 
for a mechanism to represent this would be something depending 
on the centrifugal force of the rotating wheels; but I have not 
invented any satisfactory way of representing it. The mutual 
induction of currents may be exhibited by making two circuits, on 
one of which the current is forced, and on the other of which the 
bands are simply loose. Now, on starting the first circuit, the wheels 
outside the second all rotate the same way, which I have explained 
represents an electric current in it; and the wheels inside will 
stay unmoved until the friction of the loose bands gradually sets 
them in motion, and thus, after a little while, the wheels all 
over the region are rotating just like those anywhere else, ¢. e. 
those at opposite sides of the circuit are rotating in the same 


direction, and the current has ceased in the circuit. The oppo- 
2M 2 


412 Scientific Proceedings, Royal Dublin Society. 


site effect will, of course, take place on stopping the primary 
current. 

I have thus shown how the states of the ether, that Clerk- 
Maxwell assumes, in order to explain electrical and magnetic phe- 
nomena can be illustrated by my model. It is not difficult either 
to show that the energy of the ether can be represented by equa- 
tions exactly the same as those by which Clerk-Maxwell expresses 
it. We must, however, bear in mind that my model is only a one 
dimensional one, and would require to be supplemented by two 
others in planes at right angles to itself to represent a space full 
of ether. ‘To consider, then, what the energy of the electro-mag- - 
netic field become in one dimension, I will deal with the form 
to which I reduced it in my Paper on the “ Electro-magnetic 
Theory of the Reflexion and Refraction of Light” (R. 8. Trans. 
vol. 1. 1880): The potential energy in an isotropic medium is, 


e K Ho Gh N? (Gls GEN? - ak GIB? 
W =~ rel || (Ge ae) “ge - ae) (ae ag) Lees 


while the kinetic energy is 


T= £|]| [es n+ & |e dy dz. 


Now with only one of the three coordinate planes existing, we 


must evidently make £ = 0, » = 0; and if we suppose & to be the 
angular velocity of the wheels, we evidently obtain the right form. 
tor the kinetic energy. The potential energy depends on the 


squares of +o and — = Observe that € is the angle through 


which any wheel has rotated; then it is evident that : is the 
rate of change of this angle along y, and is proportional to the 
difference of stretching of the indiarubber bands in this direction, 
?.e. to what I have compared with electric displacement in the x 


direction ; and manifestly, if the bands obey the usual laws of 
elasticity, their potential energy is proportional to the square of 


the stretching. We see similarly that the y polarisation is — 2 


It is further evident that, with three systems of planes at right 
angles to one another, we must make the potential energy depend 


FirzgerRatp—On a Model I. llustrating Properties of Ether. 418 


on the squares of (= - 2) &e., te. the strain must be propor- 
tional to these quantities. Now the simple mechanism of elastic 
bands will not do this by itself, but it is quite possible to arrange 
mechanism by which it shall be effected; for I have been able to 
invent one working by means of a fluid pumped through a net- 
work of pipes, by the rotation of wheels so arranged that an accu- 
mulation of fluid in any place tends to stop the rotation. It ig 
easy, then, to arrange that such a series of rotations as : = a = 0 
shall produce no accumulation. Having shown, then, that the 
energy of this medium can be expressed in the same form as that 
of the ether, it follows at once that all the results deduced from 
this form of the energy can be reproduced on a model. 

I have explained how it illustrates ordinary electric phenomena, 
and now I wish to show how the same medium that can illustrate 
these phenomena can also transmit vibrations analogous to light. 
If any series of the wheels be suddenly rotated, inertia will prevent 
those in their neighbourhood from being immediately rotated. 
After a little while, however, the motion will be transmitted to the 
neighbouring wheels, which will transmit it to their neighbours, 
and so on, a wave of motion being transmitted through the medium. 
If we consider the nature of the motion constituting the wave, it 
will be seen to be directed in the plane of the wave, 7. ec. the wave 
will be a wave of transverse vibration. The axes of rotation of the 
wheels are evidently at right angles to the direction of propagation of 
the wave, and what I have described as the direction of polarisation 
of the bands, is also at right angles both to the axes of rotation 
and to the direction of wave propagation. This is evident when 
we consider that the difference of rotation of neighbouring wheels 
is what causes the tightening of one side of a belt and the loosen- 
ing of the other; and the direction of polarisation of the bands is 
the line joining the centres of the tight and loose sides of these 
polarised bands, and this line is evidently at right angles to the 
line joining the centres of the two wheels whose difference of rota- 
tion causes the polarisation while this latter line is evidently the 
direction of wave propagation. Now, this is exactly analogous to 
what Maxwell describes as the nature of the propagation of light in 
the ether. The axes of rotation represent the direction of magnetic 


414 Scientific Proceedings, Royal Dublin Society. 


displacement, while the direction of polarisation is the direction of 
electric displacement. The direction of magnetic displacement is 
the direction of the plane of polarisation of the ray. 

From the fact that we can represent a medium in three dimen- 
sions, such that its equations of motion are the same as those 
Maxwell has shown must exist in the ether, it is at once evident 
that it would be possible to reproduce all the phenomena of the 
reflection and refraction of light and of polarisation of light, and 
that not merely in ordinary but in crystalline media, so that it 
would be even possible to reproduce external and internal conical 
refraction and the other peculiarities of the wave surface. ‘Two 
related cases may well be noticed—they are those of rotatory 
polarisation by crystalline and magnetised media respectively. 
The first would obviously be obtained by giving a twist to the 
planes containing the wheels, a plane polarised ray would then have 
its plane of polarisation twisted during its passage through the 
medium in the same way as the plane of polarisation of a ray of 
light is twisted in passing along the axis of a crystal of quartz. 
The phenomena of magnetised media cannot be so easily repro- 
duced. It would evidently require that something should be 
rotating in the field besides the wheels, and that it and the wheels 
should be so connected that a rotation of the wheels should tend to 
change the axis of rotation of this rotating something, which, 
reacting on the wheels, would change their direction of rotation. 
Mechanism that did this would reproduce the phenomena of the 
rotatory polarisation of magnetised media. It is worth while 
remarking how it is necessary, in order to represent this pheno- 
menon, to take into account a change produced by the wave in 
something besides the wheels, &c., which then reacts on the wave 
propagation, so that the action is altogether secondary when com- 
pared with a peculiarity of the bands or wheels themselves existing 
in any region independently of the wave passing through it. This 
latter state is analogous to the state of the ether inside a body pro- 
duced by the presence of the matter that causes its refractive index 
and specific inductive capacity to differ from unity. The disper- 
sion of waves of different rates of vibration is, on the other hand, 
a secondary action, as is illustrated by several theories of dispersion 
where the action of the matter in the wave propagation is due to a 
reaction of the matter during the wave propagation, and not a 


FirzceraLp—On a Model Illustrating Properties of Ether. 415 


permanent alteration by the matter of the nature of the medium 
of propagation : 

I need hardly say that I do not intend it to be supposed that 
the ether is actually made up of wheels and india-rubber bands, nor 
even of paddle-wheels, with connecting canals. I think, however, 
that we may learn several things as to the conditions that the 
elements of the ether should fulfil if they are to represent Maxwell’s 
equations by motions in ways analogous to those of my model. 
This supposes that quantities, such as the magnetic displacement 
that obey the laws of rotation, are really of the nature of rotations. 
If this be so, it is evident that the elements of the medium must 
be capable of rotating any number of times without any distortional 

stress being produced, so long as the neighbouring parts all rotate 
equally, while distortional stress must be produced and be pro- 
portional to the difference of rotation of the neighbouring. parts of 
the medium. It seems from this almost necessary that the ether 
must have some structure, and although Maxwell has objected to 
its having anything like a molecular structure on account of this 
supposition requiring it to possess specific heat, yet I venture to 
think that it does possess the specific heat it should possess upon 
the supposition of some sort of structure. Part of the energy in a 
volume occupied by any substance is in the form of vibrations of 
the ether within that volume, and the amount of this part of the 
energy will depend on the temperature of the body. Similarly the 
heat required to warm up a mass of silver enclosed in a non- 
conducting envelope (so that none of the energy was spent in 
producing vibrations in the surrounding ether) would depend on 
whether the silver were all in a small lump, or were in the form of 
a thin closed vessel, including a large volume of ether, for this 
included ether would require some of the energy in order to give 
it energy of vibration. Ifthe law connecting the temperature of 
matter with the energy of vibration of the ether in contact with it 
were known, it would be possible to calculate in this sense the 
specific heat of ether. As all materials are of the same tempera- 
ture when in contact with ether in the same state of vibration, this 
specific heat of the ether would be independent of the material of 
which the envelope was constructed. As the energy of the ether ig 
all in the form of its own vibrations, and is not propagated by 
conduction, but by wave propagation, it is not in exactly the same 


416 Scientific Proceedings, Royal Dublin Society. 


form as the heat energy in material bodies; but I see no reason 
for assuming that, because the ether has a structure, it must be 
capable of being a vehicle for heat energy of exactly the same form 
as that in material bodies; in fact, unless there were another ether 
bearing to the known ether the same relation as the known ether 
bears to matter, it would be impossible that the energy of the 
known ether should be in exactly the same form as the heat 
energy in matter. If the medium have a structure we can ex- 
plain electric polarisation much more satisfactorily as a change of 
structure than as a displacement. Maxwell defines polarisation 
(Elect. and Mag., vol. i. s. 60) generally thus:—“ An elemen- 
tary portion of a body may be said to be polarised when it acquires 
equal and opposite properties on two opposite sides.” He, how- 
ever, immediately afterwards calls it electric displacement, and 
there is danger from this of its being supposed to be merely a dis- 
placement of the medium in the direction of the electric displace- 
ment. It may be this, but I think is is very desirable that the 
more general notion of polarisation as a change of structure of the 
elements and not as a displacement of the elements should be 
emphazised, and it is in the latter form that polarisation is ex- 
hibited in the model. Another point to which attention is called 
by the model is the difference between the mechanical and the 
electrical stress in the medium. The model does not represent the 
mechanical stress at all. This latter depends necessarily on matter, 
for mechanical stress is a material phenomenon, and its connexion 
with the electric polarisation depends on the connexion between 
matter and ether. ‘This is true of the mechanical forces, due to 
both electrical and magnetic polarisation. That the mechanical 
stress is not connected with the electric displacement in the same 
way as material stresses are connected with their material strains 
in solids is obvious from its being proportional to the square of the 
displacement, and so being independent of its direction. All 
theories of the ether that suppose it to be simply a jelly with 
matter spread through it, like grapes in a jelly, hardly seem to 
attribute sufficient importance to the difficulty of explaining upon 
any such simple hypothesis such phenomena as electricity and 
magnetism; and although the equations of motion of the jelly 
may fairly well represent the equations of motion of the ether, as 
regards its propagation of light, yet the properties of a jelly 


FirzcERatD—On a Model Illustrating Properties of Ether. 417 


prevent our supposing continuous rotation of its elements, which 
seems almost necessary in order that the same quantities which 
represent small motions in the light propagation may represent 
known phenomena in electricity and magnetism. 

Although Professor Stokes seems to think that there is no con- 
tradiction in supposing the ether to be a jelly, and at the same 
time sufficiently little rigid to permit the free motion of matter 
through it, nevertheless, there is no doubt that this is a serious 
stumbling-block in the way of a general acceptance of the hypo- 
thesis that the ether is, in all respects, like a thin jelly, and I 
hardly think the difficulty diminished when its strains, as a rigid 
body, are required to be capable of producing permanent electrical 
forces. There are, of course, many ways in which matter may 
move through the ether besides by displacing it ; as, for instance, in 
the way in which a volume of liquid water might pass through ice, 
namely, by dissolving in front, and by freezing as fast behind, — 
and such hypotheses do not require any limit to be assigned to the 
rigidity of the ether. In all these cases it is, of course, evident, 
that when it is once shown that the energy of the medium depends 
on quantities which obey the laws of Maxwell’s electric and mag- 
netic induction and displacements, it follows that the forces on 
the places that represent the electrified and magnetised bodies must 
be the known electrical and magnetic attractions and repulsions ; 
and one great difficulty in framing hypotheses as to the connection 
of the ether and matter is in explaining how the matter moves 
through the ether. 

A very beautiful theory of matter has been founded by Sir 
William Thomson upon Helmholtz’s theory of vortex motion in a 
perfect liquid, and there seems no doubt that the simplest theory 
as to the constitution of the ether is that it is a perfect liquid. It 
seems unlikely, from Professor J. J. Thomson’s investigations of 
the properties of vortex atoms, that the simple hypothesis that an 
atom is a mere vortex ring in a liquid otherwise at rest is a suffi- 
cient hypothesis, and it seems almost impossible to explain electric 
and magnectic phenomena without some further hypothesis. The 
hypothesis that the ether is like a thin jelly in no way explains this 
property, as it is the possession of properties analogous to rigidity 
that requires explanation. Now, it seems certain that the only 
way in which a perfect liquid can become everywhere endowed 


418 Scientific Proceedings, Royal Dublin Society. 


with properties analogous to rigidity is by being everywhere in 
motion. The most general supposition of this kind wouid be, that 
it was what Sir William Thomson has called a vortex-sponge, 7. e. 
everywhere endowed with vortex motion, but with this motion so 
mixed up as to have within any sensible volume an equal amount 
of vortex motion in all directions. There are many ways in which 
this supposition seems to be in accordance with what we know of 
the properties of the ether. One would expect that electrostatic 
forces would be due to the irrotational parts of the fluid, while the 
electro-magnetic forces would be due to the rotational parts. 
There are a great many ways in which such a vortex sponge could 
be polarised. If it consisted of vortex filaments they might have 
either a solenoidal or lamellar polarisation; and if it consisted of 
vortex rings they might also have their motions polarised so as to 
move parallel to lines or planes which would correspond to solenoidal 
“or lamellar polarisations. Besides this, the axes of the vortex fila- 
ments or rings themselves might be bent, or their sections dis- 
torted, introducing thus two new sources of forces. It is thus 
visible that the proposed supposition introduces modes of pro- 
ducing force between different parts of the medium in a sufficient 
number of ways to explain not only electric and magnetic forces, 
but cohesional and chemical forces. I have not made any suppo- 
sition as to the nature of matter. The supposition that the ether 
is a vortex sponge in a perfect liquid, does not diminish the number 
of possible hypotheses as to the constitution of matter: on the 
contrary, it very much increases the possible modes of action of 
matter. I know very little as to the mechanics of a vortex sponge, 
but some points mentioned by Sir William Thomson, in a Paper 
read before the British Association at Swansea (Brit. Assoc. Rep., 
Swansea, p. 474), seem in favour of the hypothesis. In the first 
place, the energy of any polarised state of vortex motion is greater 
than that of an unpolarised state, so that if the motion of matter 
reduce the polarisation, there will be forces tending to produce that 
motion. Now, in the case of two infinite planes separated by a region 
of polarised vortex motion of any kind, it seems evident that, as 
the forces due to a small vortex vary as a high power of the dis- 
tance from it, the forces due to the polarisation between the planes 
will depend on this polarisation, and not on the distance apart of 
the planes. ‘This is the characteristic of forces varying inversely 


FirzcEratp—On a Model Tilustrating Properties of Ether. 419 


as the square of the distance from points spread over a plane. 
Sir William Thomson has also pointed out a case in which a 
polarised state of the vortex motion will be in equilibrium as long 
as it cannot produce motion of the boundary of the containing 
vessel, but in which if it can expend its energy in causing motion 
of the boundary, its energy. will be so expended. From this it 
seems likely that there are modes of polarisation of a vortex 
sponge which will be in equilibrium as far as the sponge is con- 
cerned, and whose energy can only be spent on producing motion 
of the boundaries. This is exactly the condition required in order 
to explain the equilibrium of the strained ether, which itself in 
equilibrium tends to move objects within it. If the vortex sponge 
be otherwise disturbed, 14 is obvious that the polarised state will 
become distributed through the sponge, and this should be analo- 
gous to the propagation of light. It is evident that inasmuch as 
we could neither create nor destroy vorticity, all we could do would” 
be to polarise the motion, and that all such polarisation would have 
this character of electric phenomena that we could not produce one 
kind of electrification without producing somewhere an equal and 
opposite electrification. 

I have not been able to work the theory out completely, but 
have not come across any fatal objection to it. There are a great 
many suppositions that can be made as to the nature of the polari- 
sation that represents electrostatic phenomena; and it may be of use, 
to anyone working at an hypothesis as to the nature of this polari- 
sation, to recollect that it is allowable to suppose a flow continuously 
in one direction between electrified bodies held apart by solids, for 
the electric forces are then balanced by stresses in the solid sup- 
ports, and these stresses may be due to the flow back of whatever 
is supposed to be flowing out between the electrified bodies. I do 
not expect that any flow continuously in one direction does take 
place; but there is danger of such a hypothesis being summarily 
dismissed, because of its being supposed to lead to an accumulation 
in the body towards which the flow takes place. 

In conclusion, I desire to reiterate that it seems that the only 
way in which to impart to a perfect liquid properties at all analo- 
gous to those possessed by the ether, is by supposing it full of 
motion. 


f 420 


LII.—A CONTRIBUTION TO THE NATURAL HISTORY OF 
THE HAIRS OF THE ANDRGCIUM. By GREEN- 
WOOD PIM, M.A., F.L.8. (Plates XIX. anp XX.). 


[Read, February 16, 1885. ] 


Tr is not a little remarkable that in the minute scrutiny to which 
the organs of Phanerogamic plants have been subjected of late years 
by botanists both at home and abroad, that the hairs which are to . 
be met with on the Andrcecium and Gyncecium should have been, 
at least so far as I have been able to ascertain, almost entirely 
neglected. This seems the more strange since those on leaves, 
stems, &c., have had their due meed of attention, while staminal 
hairs present much more remarkable variations both in structure 
and distribution. It cannot, I think, be doubted, that these organs 
play a most important part in the mechanism of fertilization, so. 
that here we have a fresh point of departure in that interesting 
branch of botanical science; for even in Hermann Miller’s well- 
known works these hairs are but most casually alluded to, and 
their minuter structure little, if at all, noticed. 

Dr. G. A. Weiss, of Prague, in his Allgemeine Botanik, 
published in 1878, devotes a considerable space to the subject of 
trichomes in general, but with the exception of those of Trades- 
cantia, no allusion is made to those occurring on the stamens, and 
only one or two to those of the gyncecium or pistil. Numerous 
memoirs have appeared from time to time in the Annales des 
Sciences Naturelles, Annals of Nat. Hist., Botanische Zeitung, 
and elsewhere, in none of which can I find any mention of An- 
dreecial hairs, while almost all other portions of the plant have had 
their trichome structures recorded. Dr. Weiss’s special Paper on 
the subject in Karsten’s Abhandlungen I could not obtain, as it 
does not appear to be in the Library of either the Linnean or 
Royal Societies. 

My attention was first drawn to the subject by observing the 
dense beard on the stamens of Anagallis tenella, which Sowerby 
figures as beaded hairs similar to the well-known ones in Trades- 
cantia. However, the links in the chain are very dissimilar in 


Pim—On the Hairs of the Andrecium. 421 


A. tenella from those of Tradescantia. Hach link resembles a 
dumb-bell, with prominences at each extremity like the articula- 
tions of a bone; in fact the hair is strikingly similar to a chain of 
metacarpal or metatarsal bones. Moreover, each link has a series of 
delicate spiral strize, giving it a twisted appearance. The terminal 
cell is divided into a number of rounded lobes, recalling somewhat 
anear of Indian corn. J next examined other species of Anagallis, 
all of which afforded stamen hairs, but none approaching in beauty 
or complexity to those of A. tenedia. 

It would obviously be out of the question to examine every 
flower to be met with, wild and in cultivation, as to the presence or 
absence of andrcecial hairs. I may, however, state that I have 
examined a good many, and so far the occurrence of these hairs 
is so irregular as to baffle anything like generalization. Thus 
Thunbergia alata has most curious hairs of two distinct forms, while 
the nearly allied 7. fragans is destitute of them. Justicia speciosa 
has hairy stamens; in J. flavicoma they are glabrous. Hairs may 
occur either scattered over the surface of the filament, or be con- 
fined to the anther and the base of the filament, near its point of 
insertion: if the anther is hairy, there is usually a little tuft also 
at the base of the filament, but the latter is met with without the 
former in Antirrhinum majus. 

When hairs are met with in several species of a genus, or of allied 
genera, there is commonly observable a strong likeness running 
through them, they being, as it were, variations of the same type. 
For example, all the Convolvulaceze which have come under my 
observation have hairs consisting of great numbers of cells, form- 
ing a regular tissue, but terminated in every case by a very large 
cell, which varies both in size and shape with the particular 
species. 

In very many instances, but not in all, the surface of the hair 
is somewhat roughened, either by being branched, striated, warted, 
or in some other way destined to hold and retain any pollen grains 
that may fall from the anthers, and so preserve them from the 
secretions of the plant itself, or other moisture which would tend 
to prematurely excite its development, at the same time not pre- 
venting insects from carrying it away. 

I am not in a position as yet to enter into the physiological 
portion of the question, but 1 wish merely to draw attention to the 


422 Scientific Proceedings, Royal Dublin Society. 


morphological details in the various species I have had the oppor- 
tunity of examining. As will be seen from the annexed detailed 
descriptions, every form, from the simplest to the most complex, 
are met with, and they are often correlated with more or less 
irregularity in the surface of the pollen grains. In the following 
pages the word multicellular is taken as meaning composed of 
many rows of cells, forming a mass of parenchyma; and pluricel- 
lular as designating a row of cells such as would be produced by 
transverse septa, formed in one long, more or less cylindrical, cell. 

I hope, ere long, to have the honour of submitting to the 
Society some further details on the subject, as well as possibly on 
gyneecial hairs. 

As to their morphology, we may group the various forms thus :— 


(a) Simple unicellular hairs, with smooth surface, more or less 
subulate. Malva; Campanula. 

((3) Unicellular subulate ; surface rugose, with papille. Cuphea ; 
Nerium ; Hutoca. 

(y) Unicellular, but flattened, or spathulate, rugose or striate. 
Verbascum; Celsia; Antirrhinum. 

(6) Pluricellular; simple; smooth. Salvia (some forms); Ad- 
hatoda. 

(c) Pluricellular; simple, rugose, or striate, not glandular. 
Anagallis; Goldfussia; T’hunbergia. 

(¢) Pluricellular; branched, not glandular. Browallia; Salvia 
(some forms). / 

(yn) Pluricellular, with glandular tip. Oxalis; Adschynanthus ; 

Gesnera. 

(0) Multicellular. Convolvulus; Ipomea; Lasiandra. 


Stamen hairs have been observed by the writer in the follow- 
ing nineteen natural orders, viz. :—Malvaceze, Oxalidaceze, Melas- 
tomacess, Rutaceee, Hydrophyllaceee, Lythracez, Campanulacez, 
Lobeliaceze, Convolvulaceze, Rubiaceze, Apocynaceze, Labiate, 
Acanthacez, Scrophulariaceze, Gesneraceze, Hricaceze, Primulacee, 
Commelynacez, Liliaceze ;' but it is probable that further investi- 
gation will reveal their presence in very many others. 


1 Since the foregoing was written, hairs have been observed on the stamens of Crocus, 
thus adding to the above list the Iridacez. 


Pim—On the Hairs of the Andrecium. 423 


MALVACEA. 


Malva moschata.—Hairs scattered over the filament ; tapering . 
slender; cell wall thick; suddenly contracted at the base, where 
they arise from a delicate papilla; diameter about :0015 in. 
(oleexaxe,, fie. 1) 


OXALIDACEA. 


Oxalis lasiandra.—Hairs of two kinds (a) unicellular, straight 
or curved; tapering to a blunt point; cell wall thickened; sur- 
face thickly beset with protuberances; about :0008 in. in dia- 
meter ; (0) pluricellular, clavate, glandular, thick-walled, especially 
the terminal cell, which is filled with dark contents; ‘0010 in. in 
diameter (pl. x1x., fig. 6). 


HyDROPHYLLACEA. 


Eutoca viscida.—Hairs distributed over filament, of two 
forms, viz.:—(a@) unicellular; very long and slender; tapering 
gradually ; very thin wall; slightly dotted with minute flattened 
papille, which are ovate, with long axis parallel to that of hair ; 
diameter ‘0006-0010 in. (pl. xx., fig. 1a) ; (6) shorter; glandular ; 
clavate ; pluricellular; thicker wall. Two distal cells; sometimes 
divided by vertical septa. Diameter 0070 (pl. xx., fig. 10). 


LyTHRACEA. 


Cuphea simapani.— Hairs distributed over filament; long; 
filiform ; unicellular ; intertwining; very slender; cell wall thin ; 
densely covered with minute papillz ; obtuse; scarcely tapering ; 
forming a dense wool. Diameter -0006 in. (pl. x1x., fig. 2). 


MELASTOMACEA. © 


Lasiandra macrantha.—Hairs distributed over filament; multi- 
cellular; bulbous at base; extremity clavate; glandular; formed 
of cells closely packed round a central space; cell contents purple. 
Diameter, shaft, 0015 ; head, :003 (pl. xx., fig. 4a, 0). 


Ruracea. 


Eriostemons nereifolius.— Hairs on expanded base of filament ; 
of two kinds—(a) on upper portion rather long and slender; wall 
thin; somewhat tuberculate; tubercles becoming fewer towards 


424 Scientific Proceedings, Royal Dublin Society. 


base of hair. Diameter -0008 in. (pl. x1x., fig. 3); (0) on basal 

portion shorter, with bulbous base; tapering; very thick wall; 

scarcely tuberculate ; ‘0018 in. diameter (pl. xrx., fig. 4). , 
CAMPANULACER. 

Campanula fragilis. — Hairs expanded on basal part of fila- 
ment, rather long and slender (as compared with other species of 
Campanula, in which hairs very similar, though varying greatly in 
size, are found); somewhat flexuous; wall strongly marked ; 
generally obtuse, but sometimes acute; very numerous. Diame- 
ter ‘001, by -025 long. 

CO. portenschlageana.—Hairs on base of filament obtuse ; short 
and thicker than in C. fragilis; resembling tentacles of actinia ; 
wall thin. Diameter 0015-0020. 

C. medium.—Hairs on edge of filament very short and thick ; 
somewhat papillate at top; wall well marked; closely packed. 
Diameter ‘003-005 in. by -01--03 long (pl. x1x., fig. 5). 


CoNVOLVULACEA. 


In all the members of this order which I have examined the 
hairs are very characteristic, distributed generally over the fila- 
ment; multicellular, with a large terminal cell, which, as well as the 
size of the hair, varies in different species; the terminal cell is 
least marked in Calystegia sepium and C. sylvatica, reaching 
its highest development in Jpomea purpurea and Convolvulus 
mauritanicus. In Convolvulus tricolor, a non-scandent form, the 
stamens are glabrous. 

Oonvolvulus mauritanicus.—Hairs comparatively slender ; rather 
short ; terminating in a large piliform, obtusely triangular cell, 
which is filled with granular protoplasm. Diameter -002-:008. 
(pl. xx., fig. 2). 

Ipomea learii.—Hairs very long and slender, composed of a 
great number of exceedingly delicate cells; terminal one oblong, 
obtuse; equal in transverse diameter to shaft of hair, and about 
twice aslong. Diameter -002 in. (pl. xx., fig. 5). Pollen spherical ; 
spiny. 

T. purpurea.— Very similar to I. /earii, but larger in all its parts ; 
terminal cell square. Diameter -002--003 in. (pl. xx., fig. 3). 

I. (2) species. Also similar to I. purpwrea; terminal cell longer, 
more slender, and pointed. Diameter ‘006 by ‘0015 (pl. xx., fig. 6). 


Pim—On the Hairs of the Andrecium. 425 


I. coccinea.— Hairs very short, often mere protuberances ; termi- 
nal cell scarcely exceeding the others (which are much larger than 
in other species of Ipomeea), but is flattened and oblique, resem- 
bling those of Calystegia. Diameter :006 ; terminal cell -0006 long 
by -003 wide (pl. xx., fig. 7). 

Calystegia sepium.—Hairs very short, composed as in the last 
of a few large cells; terminal cell but little differentiated. Dia- 
meter ‘003 (pl. xx., fig. 8). 

C. sylvatica. —Similar to C. sepiwm; more slender; cells 
longer; terminal cell scarcely distinguishable from others. Dia- 
meter 0025 in. 

LoBELiacEz. 

Lobelia cardinalis.—Hairs distributed on filament; dense ; vari- 
able, short and thick, or long, and somewhat slender; unicellu- 
lar ; very rugose, with minute warts. Diameter -0010 (pl. xrx., 
fig. 7). 

I. erinus.—Hairs very scanty on filament; rather short; wall 
extremely delicate; smooth, with a few comparatively long 
granules. Diameter 0008 (pl. xrx., fig. 8). Pollen slightly un- 
even in outline. 

ScROPHULARIACER. 

The hairs in this order are usually flattened, wider at the apex 
than at the base, hence often more or less spathulate (except Brow- 
allia). 

Browallia elata.—Distributed over filament; somewhat dense ; 
pluricellular ; often branching, chiefly unilaterally, like deer’s 
antlers ; somewhat thick ; wall delicate. Diameter ‘0013-:0015 in. 
(pl. xix., fig. 11). Pollen polyhedral. 

Verbascum nigrum.—Filament densely bearded with purplish 
hairs, which are large; spathulate; rugose, with minute ovate 
warts placed obliquely across the hair; variable in size. LDia- 
meter across top, 0050; of shaft, -0010 (pl. x1x., fig. 18). 
The other species of Verbascum present similar hairs, varying 
only in colour and size. 

Celsia arcturus:—Hairs very similar to Verbascum, scarcely 
distinguishable (pl. x1x., fig. 12, a, 6). 

Antirrhinum majus.—Hairs at extreme base of filament only, 
resembling those of Verbascum and Celsia, but much smaller, and 
minutely rugose (pl. xix., fig. 21). Diameter -0010. 


SCIEN. PROC. R.D.S.-—VOL. IV. PT. VII. 2N 


426 Scientific Proceedings, Royal Dublin Society. 


GESNERACEA. 


Gesnera insignis.—Hairs distributed over filament; pluricellular; 
rather large ; thin walled ; knobbed at the extremity ; glandular; 
terminal cell subdivided into several by perpendicular septa, and 
filled with dark coarsely-granular protoplasm (pl. xx., fig. 11). 
Diameter -0010 in. 

Eucodonia sp. (garden hybrid).—Hairs pluricellular, knobbed, 
but not glandular; more slender than in the last; wall delicate. 
Diameter -0008 in. (pl. xx., fig. 10). 

Aeschynanthus splendens.—Hairs scattered over filament, resem- 
bling those of Gesnera insignis, but smaller; pluricellular ; glan- 
dular terminal cell, divided by perpendicular septa, as in G. i- 
sigs, septa fewer in number. Diameter ‘0007-8 in. (pl. xx., 
fig. 9). 

APOCYNACER. 


Nerium oleander.—Hairs clothing filament with a soft woolly 
coating; very slender; unicellular; wall well marked; rugose, 
with minute oblique warts. Diameter ‘0008 in. (pl. x1x., fig. 9). 


RUBIACE®. 


Toxicophlea spectabilis—Hairs of two kinds—(a) on anther ; 
unicellular; rather short; flattened; slightly rugose, with ex- 
tremely minute papille; diameter -0008 in.; (0) on filament 
longer, but unicellular; subulate; obtuse, with one or two slight 
swellings of the cell wall; partly filled with large rounded 
granules. Diameter about ‘0008 in. Similar hairs occur on the 
corolla tube. 

Vinca major.—Hairs on extremity of anther and at base of 
filament, where it is inserted into the tube of the corolla; both 
unicellular; surface faintly undulated. Those on the anther, with 
thinner walls and longitudinally striate. Diameter 0008. Those 
at base of filament with stronger walls, also striate, and with-very 
granular protoplasm. Diameter :0010. Pollen smooth. 

Vinca minor.—Hairs very similar, both as to form and arrange- 
ment, to those of V. major, but outline of anther hairs more 
undulated and scarcely striate. Diameter ‘0008-0010. Pollen 
smooth, with three or four projections. Basal hairs less undulate 
but more striate. 


Pim—On the Hairs of the Andrecium. 427 


LABIAT A. 


Salvia is the only genus of the order in which I have observed 
andreecial hairs. 

S. splendens.—Scattered over filament, pluricellular, very deli- 
cate, wall very thin, usually simple, rarely branched; tip very 
obtuse. Diameter :0010. 


The closely allied S. heeri has very similar hairs, but more 
swollen at the nodes. 

S. fulgens.—Hairs large, deep red, wall strongly marked, 
rarely branched, slightly verrucose, with minute warts. Diame- 
ter ‘0010. 

S. rutilans.— Almost simple, short, thick, wall delicate, uni- 
cellular. Diameter -0015 (pl. xix., fig. 14). Pollen slightly 
rugose, deeply sulcate. 

S. leucantha.—W hile the whole plant, especially the calyx, is 
unusually downy, the stamens are nearly glabrous, the hairs which 
do occur differing considerably from those of the other species 
I have examined. Those on filament—(q) are very short and 
thick, either obtuse or capitate, consisting of two or three flattened 
cells. When capitate the head is nearly globose; (4) at base of 
filament very short, simple, obtuse, scarcely more than papille ; 
unicellular. 


PRIMULACE®. 


Anagallis arvensis—Stamens very woolly ; hairs pluricellular, 
with delicate wall; lower cells oblong; upper two nearly spherical; 
all delicately striate, with longitudinal striz; deep purple in 
colour, whether petals happen to be red, blue, or white. Diameter 
“0008 (pl. xx., fig. 12). 

A. parksii (monelli) (pl. xx.,( Very similar to A. arvensis, 

fig. 13). but with terminal segments 

A, phillipsii (pl. xx., fig. 14). more oblong. 


A. indica (pl. xx., fig. 16) has terminal cell more spherical, 
and showing traces, occasionally, of a vertical septum. 

A. var. Napoleon III, (pl. xx., fig. 15). Segments longer; 
broader at ends than in the centre, thus somewhat resembling such 
a bone as a human femur or humerus. In all these forms the cell’ 
wall is exceedingly thin, but appears often somewhat thick on 


428: Scientific Proceedings, Royal Dublin Society. 


account of the protoplasm contracting but slightly, the space between 
the mass of protoplasm and the wall appearing to be the wall itself. 
In the terminal cell becoming vertically septate (A. indica), and the 
resemblance to a bone (A. Napoleon III.), we trace the transition 
to the most differentiated form, A. ¢enella, which is very distinct 
in habit and flower from all the others, while in the strikingly 
similar (to A. arvensis) Lysimachia nemorum the stamens are 
quite glabrous. The pollen in the five species just described is 
somewhat triangular in outline. 

A. tenella.—Filament woolly, with pluricellular hairs, the 
lower segments of which resemble dumb-bells, with knobs project- 
ing from the ends at right angles to the long axis; they might 
also be likened to metacarpal bones, as before mentioned. Ter- 
minal cells much smaller, rounded, arranged in a kind of ear- 
like form, arising from repeated transverse and vertical septa ; 
all with a delicate spiral striation (pl. xx., fig. 17). Diameter 
‘0007--0012 (across knobbed portion). In the young bud we find 
hairs in all stages, from the simple pluricellular form of A. phil- 
lipsit to the fully developed form. Pollen small, smooth, oval. 


ACANTHACER. 


Hairs occur in many genera and species, and vary a good 
deal, but are generally pluricellular, often presenting two or more 
types on different parts of the same stamen (Acanthus, Thunbergia). 
In Acanthus the hairs are very largely developed, the anther 
having quite a brush-like appearance. 

Acanthus spinosus.—Hairs occur both on anther and at base of 
filament. Those on the anther are of two forms—(a) short and stiff, 
forming a dense brush on the ventral suture of the anther, with 
the surface reticulated in a labyrinthiform manner; (b) on the 
dorsal portion of the anther, longer, more flexuous, stronger walls, 
and with only longitudinal strize. The position of these dorsal 
hairs varies according to whether the anthers are those of the 
interior or exterior pair of stamens, the anthers of the latter being 
closely appressed to each other by their ventral sutures. The 
basal hairs resemble those dorsally situate on the anther. Their 
‘diameters are about the same, viz., ‘0010 in. (pl. x1x., fig. 18). 
Pollen oval, slightly papillate. 


Pin—On the Hairs of the Andrecium. 429 


Acanthus montanus.—Arrangement of hairs similar to A. 
spinosus, but sutural hairs not reticulated, and scarcely differing 
from dorsal, except in having a blunt tip, while the latter are 
somewhat knobbed. Diameter ‘0010. Pollen round, smooth 
(Glepsix., we. 19 a7 andy) 

Thunbergia alata. —Hairs of two kinds—(a) clothing edge of 
anther, pluricellular, upper cells large, spheroidal, thick-walled ; 
terminal, one or more septate; lower oblong, all thickly beset 
with prominent warts; diameter :0010--0025 in. (pl. xx., fig. 
19); (0) at base of filament, thick, pluricellular; cells long, 
oval, terminal, flattened transversely ; wall rather thin, scarcely 
at all scabrous; protoplasm very granular; proximal segment 
smallest. Pollen spherical, with enveloping spiral band (pl. xx., 
fig. 18). 

Justicia speciosa.—Hairs on filament short and thick, or some- 
what slender; pluricellular ; slightly scabrous; wall rather thin ; 
deep purple; curved. The endochrome has the remarkable pro- 
perty, in common with that of the petals, &c., of crystallizing 
into minute prisms of dark purple colour. Diameter, thick hairs, 
0015; slender, -0010 (pl. xix., fig. 17). 

J. flavicoma.—Authers glabrous. 

Goldfussia anisophylla.—Hairs on filament long; flexuous; lon- 
gitudinally flattened; pluricellular ; simple or slightly branched ; 
wall delicate; scabrous, with minute warts, asin Verium, Verbas- 
cum, &c. Diameter -0007 (pl. xix., fig. 16). Pollen nearly 
round ; furrowed ; slightly roughened. 

Adhatoda cydoniefolia.—Hairs on filament thickly disposed ; 
pluricellular; somewhat swollen at septa; wall well marked; 
slightly striate longitudinally; point acute. Diameter -0010 
(pl. xix., fig. 20). 


ERICACER. 


Arbutus unedo.—Expanded portion of filament thickly beset with 
rather long, extremely delicate, unicellular, simple hairs, which 
are very slightly scabrous with minute oval projections; about 
0004 in. in diameter. These are the slenderest hairs I have met 
with) (pl: xix., fie. 21). 

Arbutus procera.—Hairs undistinguishable from those of A. 
unedo. 


430 Scientific Proceedings, Royal Dublin Society. 


MONOCOTYLEDONES. 


CoMMELYNACEA. 


Tradescantia virginica.—Stamen thickly covered with dark 
blue hairs, in which, as is well known, the rotation of the cell sap 
can be seen. ‘They are pluricellular, much constricted at the 
septa, so as to form a bead-like structure. 

Tradescantia zebrina and Commelyna celestis present similar 
hairs. 


LILIAceZ. 


Yucca sp.—Hair on filament very thick; rather short and ob- 
tuse ; unicellular, with longitudinal striz; wall (proportionately) 
thin. Diameter -005 (pl. x1x., fig. 15). 

Narthecium ossifragum.—Hairs on filament; pluricellular, rather 
slender, obtuse; wall delicate; closely striate, with spiral stric ; 
each cell containing a considerable number of bright orange 
globules of various sizes and shapes, probably oil of some kind. 
Diameter ‘0010 (pl. x1x., fig. 22). 


DESCRIPTION OF PLATES XIX. anp XX. 


PLATE XIX. 


On Plate XIX., figs. 1, 4, 5, 7, 12a, 15, 20, are magnified about 40 diameters; figs. 2, 3, 
6, 8, 9, 10, 11, 124, 18, 14, 16, 17, 18, 19, 21, 22, about 175 diameters. 


Malwa moschata. 
Cuphea zimapan. 
Eriostemon neriifolius. 
Hair on upper portion of filament. 
» 4. Hriostemon nertifolius. 
Hair from lower portion of filament. 


w Nb = 


>»  o Campanula medium. 
» 6. Oxalis lasiandra. 

»,  @- Lobelia cardinalis. 
» 98. Lobelia erinus. 


>» 9  Nerium oleander. 
» 10. Antirrhinum maus. 


Basal hair. 
>» Ll. Browallia elata. 
» 12. Celsia arcturus. 


a. Group of hairs; 4. Single hair highly magnified, 


Pim—On the Hairs of the Andrecium. 431 


Description oF PratE XIX.—continued. 


Fig. 


13. 
14. 
16. 
16. 
Ie 
18. 


19. 


Verbascum nigrum. 
Salvia rutilans. 

Yucca sp. 

Goldfussia anisophylla. 
Justicia speciosa. 
Acanthus spinosus. 

Hair on suture of anther. 
Acanthus montanus. 

a. Sutural hair; 46. Dorsal hair. 
Adhatoda cydonicefolia. 
Arbutus unedo. 
Narthecwum ossifragun. 


PLATE XX. 


On Plate XX., figs. 2 and 18 are magnified about 40 diameters—all the rest 


a 
° 


175 diameters. 


Eutoca visida. 

a. Ordinary hair; 4. Glandular hair. 
Convolvulus mauritanicus. 
Ipomea purpurea. 

Extremity of hair. 
Lasiandra macrantha. 

a. Longitudinal section; 4. Surface of tip. 

(Diagrammatic.) 
Ipomea learii. 
Extremity of hair. 
I. (?) species. 

Extremity of hair. 
Ipomea coccinea. 

Calystegia sepium. 
Lischynanthus splendens. 
Eucodonia (?) species. 
Gesnera insignis. 

Tip of hair. 

Anagallis arvensis. 

Anagallis monelli (parksir). 
Anagallis phillipsi. 
Anagallis, var. Napoleon I11. 
Anagallis indica. 


.  Anagallis tenella. 


Thunbergia alata. 
Basal hair. 

Thunbergia alata. 
Anther hair. 


P1432 


LITI.—ON A SET OF MUSICAL STONES IN THE SCIENCE 
AND ART MUSEUM, DUBLIN. By BENJAMIN H. 
MULLEN, B.A., DUBLIN. 


[Read, January 19, 1885. ] 


Tue stones now exhibited, by permission of the Director, Science 
and Art Museum, formed a set of musical stones which were on 
view in the Museum of the Royal Dublin Society about twenty- 
five years ago; many years before they were handed over, with 
the entire collections of the Society, to the Science and Art 
Department. They were found in a box in a store-room a few 
months ago; and, having been brought to light and arranged, 
they form the rude, but tuneful instrument known as the Rock 
Harmonicon. 

But, before entering into any particulars about these, it might © 
be interesting to say something of musical stones in general. 

From a work by Fétis, entitled L’ Histoire Générale de la 
Musique, we learn that different sonorous stones are found in 
China, the best of which, called yu,' is hard, heavy, and close- 
grained, and takes a polish like agate. These stones are given an 
uniform shape, and are arranged in a series conformable with the 
tonal system of the Chinese. The arrangement of this series of 
sounding-stones is called king. The stone yw is put into vibra- 
tion by a blow from a metal hammer or wooden mallet. Their 
shape, as I gathered from an illustration in the above-mentioned 
work, is like a pistol-holster, flattened considerably. They are 
suspended in two rows of eight from the bars of a framework of 
wood, somewhat resembling a large clothes-horse in appearance. 
The smaller stones are hung from the upper bar, the larger from 
the lower. 


1 The Chinese yw stone is Jade. According to Goez (16th century) this stone was 
sold at ‘‘exceeding great rates’’ in China, and was regarded as most precious. 


Mourien—On «a Set of Musical Stones. 433 


From another source' we hear that among the ancient Chinese 
musical instruments is the pein king, which is an assortment of 
sixteen stones arranged on strings in two series of eight each, one 
above the other, and giving out, when struck successively, the 
system of sounds employed by the ancient Chinese in their music. 
The size and shape of these stones have been very carefully deter- 
mined by them, after a minute analysis of the sounds peculiar to 
each one. In order to render the sound graver, the thickness of 
the stone is diminished to the right amount, and to render it more 
acute something is cut off its length. Frequent endeavours have 
been made to decide what kind of stone was employed, since they 
were customarily paid as tribute-money, more than two thousand 
years before Christ, by certain provinces in China. Some authors 
have thought they recognized in them a kind of black marble; 
and the editor of the works of Father Amiote asserts that the 
musical stones constructed in France, with the black marble of 
Flanders, were quite as sonorous as those of China. 

The ancients turned to account the acoustic properties of cer- 
tain kinds of stone in a remarkable way.” Pausanias tells of a 
marvellous stone that was placed as a sentinel at the entrance of a 
treasury ; and that robbers were scared away by the trumpet tones 
which it sent forth. Several kinds of stone have this property of 
resonance, and it is probable that a stone of this description was so 
suspended as to be struck by a projecting piece of metal when the 
external door of the treasury opened. 

The clink-stone indicates by its very name its sonorous quali- 
ties. The red granite of the Thebaid in Egypt possesses similar 
properties. And so musical are the granite rocks on the Orinoco, 
that the natives attribute the sounds to witchcraft. In Brazil 
travellers have seen large blocks of basalt which emitted very 
clear sounds when struck; and the Chinese employ this stone in 
the manufacture of musical instruments. 

Many years ago a discovery was made at Kendal, in West- 
moreland, of some musical stones which, when struck with a piece 
of iron, or another stone, gave out sounds of very different pitch, 
and with eight of which it would be possible to attain a very dis- 


1 The Practical Dictionary of Mechanics, by Edward H. Knight, C.E. 
* [The World of Wonders. 
SCIEN. PROC. R.D.S.—VOL. IV. Pi. VII. 20 


434 Scientific Proceedings, Royal Dublin Society. 


tinct octave. And a correspondent of Natwre writes that, in 
roaming over the hills and rocks near Kendal, which are composed 
chiefly of limestone, he had often found what are called musical 
stones. They are generally thin, flat, weather-beaten stones, of 
different sizes and peculiar shapes, which, when struck, produce a 
musical tone instead of the dull, heavy, leaden sound of an ordi- 
nary stone. ‘The sounds of these stones are very much alike; but 
sets of eight have been collected which produce a distinct octave. 
The French scientific weekly, La Nature copied the communi- 
cation from its English namesake, and brought forward an addi- 
tional instance of the same phenomenon. It told of a performer 
who played airs on rough flints suspended by silk threads, striking 
them with an iron rod. And, to come nearer home, Ireland is not 
without her singing stones. I hear there is a bridge, between 
Ballina and Belmullet, whose coping stones are particularly 
sonorous. 

With regard to the set at present before us, there is, unfortu- 
nately, very little information to be had. ‘They were presented to 
the Royal Dublin Society by Miss Hunt, of 10, Upper Merrion- 
street, on 1st December, 1857—more than twenty-seven years ago— 
under the title of “A Set of Musical Stones from Cumberland.” 

A set of probably similar stones, consisting of sixty pieces, 
varying in length from six inches to four feet, and having 
a compass of five octaves, was collected about thirteen years 
ago in Cumberland by an artizan named Till, of Keswick.’ 
This, like the set in the Science and Art Museum, is not a mere 
musical curiosity, but an effective instrument which draws a 
hall full of people whenever its inventor appears in public. He 
would deserve such support, for the time occupied in com- 
pleting the set was eleven years. I believe its range has since 
been extended by some fifteen or twenty stones. ‘Three perform 
on it at the same time; and the effect is as pleasing as it is 
novel. At the late Amsterdam Exhibition, and elsewhere since, 
a lrenchman exhibited a set of twenty-five large, clear-sounding 


1 Mr. Peter Crosthwaite, founder of the Crosthwaite Museum, Keswick, discovered 
the first musical stones, on June 11, 1785, on the sand-beds of the river Greta, near 
Keswick. This set consists of sixteen in number, upon which any tune in the natural 
key can be played. They are composed of hornblende slate and gneiss. two of the 
lower rocks of the Skiddaw strata.—Notes and Queries, No. 267, p. 112. 


Muiten—On a Set of Musical Stones. 435 


flints; and, as with that in the Museum, there was no relation 
between the weight, size, or shape of the stones and the notes 
produced. He asked for it the modest sum of sixty thousand 
franes, nearly £100 for each stone. But the collection was the 
result of thirty years’ labour. 

The stones in the Museum are Limestone. 

Some imagine that they are virgin stones, unhewn, unshaped 
but by nature; while others maintain that they have been tuned 
by chipping pieces off the edges. Both these ideas may be cor- 
rect; they are not really incompatible. The stones are unhewn, 
and have no particular shape except thinness. But what could be 
more natural than for the collector, when he had found a stone 
nearly in tune, to try the effect of chipping. This “tunes” it, 
but does not give it resonance, for that belonged to the original 
stone in its virgin condition. 

I tried an experiment on one of them, which had a duplicate 
im the scale of B flat, and noted the result. The stone (which 
seemed to have been broken before), weighed 273 grammes, and 
produced the note I’, when struck. A piece was carefully removed 
by a stonecutter, and I then found it to weigh 247 grammes. 
Thus it lost 26 grammes, or 37; of its entire weight; and the effect 
of this was to raise the pitch a full fourth—to B flat. This note is 
almost beyond the perception of the human ear; but the experi- 
ment places beyond a shadow of a doubt the fact that the stones 
can be tuned. It would also appear, on comparing the cause and 
effect, that the tuning is a very delicate operation. When pieces 
are removed from the edges the pitch is raised, and when taken 
from the flat sides it is lowered ; and if, perchance, too much is 
removed in one way, it must be rectified in the other. 

The evident difficulty of tuning the stones will account for the 
fact that only some four or five of this set are actually correct; 
the others are very nearly so. In general aspect the stones become 
smaller and lighter as the scale ascends; but there seems to be no 
relation between the weight and tone in any particular case. Take, 
as perhaps the most prominent instance of this, counting from the 
lowest note, Nos. 5 and 6. No. 5 weighs 792 grammes, while 
No. 6 weighs 1880 grammes; and though the latter is, nearly two 
and a-half times as heavy as the former, it produces a,note a semi- 
tone higher. “Then, again, Nos. 7 and 8. ‘The former, G, weighs 


456 Proceedings of the Royal Dublin Society. 


1485 grammes; while the latter, F, weighs only 437 grammes. 
In this instance the lower note is about three and a-quarter times 
the weight of the higher. Many other incongruities could be 
shown, did space permit. 

The ringing quality of the stone depends on its points of sus- 
pension. Of course there are lines of vibration in the stone, and 
in these lines are nodal points, or points of no vibration. It is at 
these points the stone must be supported, otherwise the support 
will greatly interfere with the ring of the note. A stand con- 
structed to meet this would be a most complicated one. Besides 
that, it must be so long that the walking exercise of scale playing 
would be so very exhausting as to entirely overcome tke pleasure 
derivable from the otherwise entrancing performance. 

Some of these stones give out a double sound; the lowest, for 
example, when struck, sounds A flat and EK natural—a minor 
sixth. But I will merely draw your attention to two. First, 
No. 7 produces G and B flat—a minor third; the whitened part 
of the stone gives G, and the points which give the most distinet 
B flat are reddened. The other is No. 10. This is C, producing 
also D—a full tone. The C-producing part is white, and the D-, 
where clearest, blue. You will observe that these stones have four - 
points (marked with black dots on the white ground) diametrically 
opposite each other, which give the true note of the stone, while 
between each of these is a spot where the fa/se note is given very 
clearly ; and in the centre, where the lines of vibration cross, it is 
impossible to get either note true. 

In conclusion, this Rock Harmonicon is an effective musical 
instrument, made of limestone in its natural condition; contains 
some stones which produce double sounds—some in sixths, some in 
thirds, some in seconds. That such sets are not common may be 
gathered from the fact that so little information is to be had con- 
cerning them. 


fedaq 4 


LIV.—NOTE ON SELENO-CARBAMIDE. By PROFESSOR 
EMERSON REYNOLDS, M.D., F.R.S. 


[Read, January 19, 1885.] 


Tux subject of the present “Note” is the selenium analogue of a 
body whose isolation I had the honour to announce to the Royal 
Dublin Society in 1869, namely, thio-carbamide. The following 
formule indicate the relations of thio- and seleno-carbamides :— 


THIO-CARBAMIDE. SELENO-CARBAMIDE. 
NH, NH 
Oo ae | O8e aE 


The method by which I succeeded in producing the sulphur 
compound was the intra-molecular rearrangement by ammonium 
throughout. But the same body can be obtained by the action 
of hydrogen sulphide on cyanamide, thus :— 


NH, 
HS + CN - NH, = Cs NH, 


The close analogy existing between sulphur and selenium led 
us to expect that seleno-carbamide would be obtained by methods 
similar to those which have proved successful in the case of the 
sulphur compound. I was aware that several chemists unsuccess- 
fully attempted to produce the body by the molecular rearrangement 
of ammonium seleno-cyanate; and, having recently prepared con- 
siderable quantities of cyanamide, I decided to try whether the 
second method would prove more successful, namely, the action 
of hydrogen selenide on cyanamide. ‘The experiment, which 
proved successful, was conducted as follows :— 

Four grams of cyanamide were dissolved in 50 ces. of anhydrous 
ether, and a slow current of hydrogen-selenide was passed through 
the solution under a pressure of about 60 mms. of mercury. The 
gas was slowly absorbed, and at first some selenium separated 


SCIEN. PROG, R.D.S.—VOL. IV. PT. VIII. 9) IP 


438 Scientific Proceedings, Royal Dublin Society. 


from the liquid ; but on continuing the treatment, beautiful colour- 
less crystals formed on the sides of the vessel. The crystals 
were drained from the ethereal liquid, and when exposed to the 
air were found to be easily reddened by the action of light; they 
were dissolved in a small quantity of hot water, the solution 
filtered and then cooled, when beautiful silky crystals separated 
which very closely resembled thiocarbamide in appearance, and 
mode of crystallization. The purified compound proved on ana- 
lysis to be CSe (NH,),. 

When this point had been reached, the author learned from 
the January number of the “Journal of the Chemical Society of 
London,” that M. A. Verneuil had just published an account of 
the same body in the Bulletin de la Societé Chemique de Paris. 
I therefore did not continue the investigation, as M. Verneuil is 
fully entitled to priority, but now content myself with the exhi- 
bition to the Society of the specimen of seleno-carbamide produced — 
in the Dublin University Laboratory. 


[ 439 ] 


LY. — ON AN ANALOGY BETWEEN ELECTRIC AND 
THERMAL PHENOMENA. By GHORGEH FRANCIS 
FITZGERALD, F.T.C.D. 


[Read, November 17, 1884.] 


THE object of the following communication is to show how little 
we know of the nature of what are called electric currents, by 
pointing out that electric quantities may be described in terms of 
temperature and entropy just as satisfactorily as in terms of pres- 
sures and volumes, which are the terms analogous to electric poten- 
tial and quantity of electricity in consonance with the usually 
drawn analogy between an electric current and a current of an 
incompressible fluid, upon which is founded such terms as electric 
current and electric displacement. The thermal analogy usually 
drawn is between quantity of electricity and quantity of heat; but 
I think the analogy I am pointing out in every way preferable, for 
energy is of the nature of temperature by entropy, just as it is of 
the nature of pressure by volume or potential by quantity of elec- 
tricity. The work done in bringing a quantity of entropy, ¢, from 
temperature 7, to T, is W = (T, — T.)@; and if the transference be 
effected in a reversible manner the entropy taken from one source 
is equal to that given to the other. Indeed we can easily conceive 
of systems in which all transference of entropy is effected without 
loss, and in that case the quantity of entropy would be constant. 
It is to be observed that the temperature and entropy of a body 
are quite independent of one another, so that we can suppose either 
to be altered while the other remains constant. If we apply this 
conception to electrostatic phenomena, we must call potential the 
temperature of the ether and quantity of electricity its entropy. 
As the same relations connect these pairs of analogues with energy 
they will obey similar laws, and what is further required is to show 
how it may be supposed that bodies at different temperatures can 
throw the intervening medium into the sort of stress that Maxwell 
has shown is required to explain electrostatic forces. I premise 


that Maxwell has not made any attempt in his electricity and 
3 DIP 9 


440 Scientific Proceedings, Royal Dublin Society. 


magnetism to make the corresponding step of showing what sort 
of a thing an electric displacement is that it may produce these 
stresses, so that the line I am pointing out goes beyond Maxwell’s 
analogy, but must be considered as only a dim sort of hypothesis, 
and not as a complete theory. 

In the first place, it is evident that a non-conductor must be a 
medium that can have different temperatures at different parts 
without entropy being conducted from one place to another, 7. e. 
without conduction of energy; and a conductor must.be an engine 
that transfers entropy undiminished, and always produces heat or 
work equivalent to the degradation of entropy. 

Now a distribution of molecules of a gas and their velocities is 
possible by which there would be stresses in the gas similar to those 
required by electrostatic phenomena, and yet without either cur- 
rents of gas or conduction of heat taking place. The molecules of 
a material gas do not get themselves or their velocities distributed 
in this way by differences of temperature: in all material gases 
there is certainly conduction of heat, but it seems probably possible 
to invent a law of action between molecules which shall produce 
any required law of distribution of molecules and their velocities. 
A somewhat similar problem was solved by Maxwell when he cal- 
culated the law of force between molecules, in order that the tem- 
perature at all points in a column of gas subject to gravity might 
be the same. As the whole thing is so hypothetical, I have not 
thought it worth while attempting to work out the law of action 
between molecules that would account for the distribution of velo- 
cities required by my hypothesis. 

If the number of molecules going in a direction defined by a 
direction angle 0 be represented by (wu = cos 9) , 


M = My) + Mz (un? — 4) ; 
and if the velocity of the corresponding molecules be 
v= et ea( - 9), 


then there will be neither currents of gas nor to the second order 
of small quantities any conduction of heat, but the pressure will be 
different in different directions, and will be parallel to the direction 
from which @ is measured, 


pi=P +p, 


FirzGERALpD--Eleetric and Thermal Phenomena. 44] 


and in every direction at right angles to this 


pr= P- p, 
where 


P = $1 (Vo — F02) {MoV + Hi Vz — 2Mg Le + qs (12% + QM) — M2%2)}, 
and 
p = 22a (0) — Sey) (mor + 21002 — 2%} - 


If in this m, and v, be negative quantities, p will be negative, 
and the state of stress will be a pressure less than the average along 
the line from which @ is measured, and an equal excess above the 
average pressure in every direction at right angles to this; and this 
is the state of stress that Maxwell has shown will explain electro- 
static forces. 

If we take the particular case of two parallel planes and sup- 
pose P and p constant all the way across, as they evidently must 
be, we have, supposing m,=0, that mov? and mx must be 
constant as we go across, so that » and v, must vary inversely 
as the square root of 1; and if we suppose temperature defined 
by the square of the velocity, i.e. by ~% we have that it must be 
of the form 7, + 7, where 7, and T, are constants and r the dis- 
tance from one of the planes. 

In this method of describing electrostatic phenomena, what 
Maxwell calls the electric displacement would be proportional to 
the square root of py; and what he describes as the polarisation of 
the medium I would describe in the same words, and explain as a 
distribution of the molecules and their velocities in which these 
were not uniformly distributed in every direction. 

I have not propounded any hypothesis as to the nature of con- 
duction, but it would evidently correspond to a transference of 
entropy by means of heat engines which would produce heat cor- 
responding to the resistance of the conductor, and also produce 
magnetic phenomena in the neighbouring dielectric. I have not 
propounded any hypothesis as to the nature of magnetic displace- 
ments, but it seems probable that they might be ‘Illustrated by 
introducing molecular rota tion. 

fam bringing forward -his communication no at all so much 
for the sake of the hypothesis it contains as for the sake of calling 


442 Scientific Proceedings, Royal Dublin Society. 


attention to the purely analogical nature of the description of 
electric currents as currents, and electric displacements as displace- 
ments. The analogy between electric currents and currents of an 
incompressible fluid is so complete and so easily drawn, that there 
is serious risk of our being as much hampered in future advances 
by our imagining this analogy to be a likeness as we have been in 
the past by the theories of action at a distance, which still control 
the text-books and the ordinary methods of speaking of electrical 
phenomena to such an extent that most people find it almost im- 
possible to think of electric and magnetic phenomena in any other 
light. For fear of our being similarly hampered by the words 
“electric displacement” and “ electric current,” I think it worth 
while pointing out that just as these words presuppose an analogy 
between electric quantity and volume of liquid, and electric poten- 
tial and pressure of liquid, similarly it is quite possible to draw 
another analogy, namely between electric quantity and entropy, 
and electric potential and temperature, so that, with these two dif- 
ferent analogies in view, it may be the less likely that the student 
should look upon either as anything more than an analogy, until 
further investigation shows that there is either a real likeness to 
one or the other, or that the electric phenomenon is sui generis, 
and unlike either, which latter is in my opinion the more probable 
supposition. 


aes 


LVI.—ON AN HEXACTINELLID SPONGE FROM THE GAULT, 
AND A LITHISTID FROM THE LIAS OF ENGLAND. 
By PROFESSOR W. J. SOLLAS, M.A., D.Sc. (Prate 
OME) 


[Read, February 16, 1885. ] 


Foss sponge remains are exceedingly rare both in the Lias and 
Gault deposits of Europe. Fragments of sponge-skeletons and 
scattered spicules have been described from Liassic strata in Aus- 
tria, and occasional spicules are met with in the English Lias; but 
hitherto no entire sponge. 

The Gault of Cambridge contains not uncommonly so-called 
“coprolites,” which have every external appearance of sponge- 
remains, but which on the other hand are usually devoid of inter- 
nal structure. 

The discovery by the Rev. P. B. Brodie, m.a., ¥.G.s., of two 
complete and sufficiently well-preserved sponges, one from the Lias 
and the other from the Gault of England, is consequently of con- 
siderable interest; Mr. Brodie, recognising this, has placed his 
specimens in my hands for description, and I now offer the fol- 
lowing account of them, commencing with the specimen from the 
Lias :— 

PLATYCHONIA BRODIEI (sp. n.). 


Sponge, irregularly pouch-shaped ; higher on one side, which 
is 5) mm. in length, than on the other, which measures 23 mm. 
in length. Central cavity large, 31 mm. across. Wail of slightly 
variable thickness — about 8 mm. where highest, and 10 mm. 
where lowest: both surfaces uneven, with irregular elevations and 
depressions ; otherwise smooth. Ostia small; on the outside, from 
about 0:1 to 0:15 mm., round or oval; on the inside, 0:1 to 0:4 
mm. in diameter, round, oval, or irregular; without a raised 
margin, even with the surface. 

Canal System. Fine and irregular. Small canals rarely enter 
the wall perpendicular to the surface, and, when they do so, lose 
themselves in the interior. No vertical tubes. 


444 Scientific Proceedings, Royal Dublin Society. 


Skeleton. Small, slender rhizomorine corpuscles, arranged upon 
no evident plan. 

Horizon. Marlstone, Lias. 

Locality. Uminster, Somerset. 

Remarks. The form of the sponge is such as would be produced 
by the incurving growth of a lobate fan-shaped expansion to form 
an irregular cup. ‘The highest part of the cup represents the 
median line of the fan, the lowest part the united edges. An 
incrustation of oolitic rock covers the surface in places; but, when 
this is absent, a dark-brown ferruginous layer is evident, in which, — 
however, no structure such as might indicate the presence of a 
special dermal covering layer is discernible. On treating the 
surface with acid the ostia are rendered visible, as round or oval 
areas, bounded by the skeletal corpuscles in characteristic Lithis- 
tid fashion. ‘They are not quite so well defined on the inner 
surface of the wall, and, though oval and round in most cases, 
appear there sometimes as quite irregular spaces. 

The originally siliceous skeleton has been entirely replaced by 
carbonate of lime, and the structure of the nodes of the skeleton 
where interlocking occurred is completely obliterated. The cor- 
puscles do not offer any characters which can be made use of for — 
the discrimination of the species. Several sections of Milliola occur 
in the adherent rock-material. | 


CRATICULARIA CALATHUS* (sp. 2.). 


Sponge, vasiform or funnel-shaped, with undulating margin, 
slightly expanded above; tapering below to form a short stem, 
which ends abruptly in an oval scar; no evidence of attachment ; 
height, 51 mm.; maximum diameter, 60 mm.; minimum, 36 
mm. Wail of nearly uniform thickness, 6 to 7 mm., rounded 
at the edge, on the outside without ostia, on the inside bearing 
ostia arranged in vertical and horizontal rows more or less at right 
angles to each other. 

Ostia apparently oval, elongated longitudinally ; in a horizontal 
row 6 occur in a distance of 9 mm.; in a vertical row 5 in 12 mm. 

Skeleton. Nodes not thickened, and imperforate. 


* ndAados, 6, a basket. 


Sottas—Hewactinellid Sponge from the Gault, &c. 445 


Horizon. Lower Gault. 

Locality. Cambridge. 

Remarks. Of cretaceous sponges this most nearly resembles 
Craticularia vulgata, Pocta, and C. sitteli, Pocta, but differs partly 
in shape, since it does not expand at the base, as both these sponges 
do, and partly in the size of the oscules, which, judging from com- 
parison with Pocta’s illustrations, are larger than those of C. vu/- 
gata and smaller than those of C. sittei. The inner surface is, 
however, very similar to that of C. vulgata. The skeleton, or what 
indications remain of it, appears to have been characterized by 
much slenderer or thinner fibres than occur in Pocta’s species. The 
sponge is mineralized with iron pyrites, in the far from common 
form of simple octahedra, the faces, edges, and quoins of which 
project in all directions from both surfaces. In the interior, as 
shown by slicing, other faces as well as those of octohedra occur; 
they are striated in a marked manner, and may indicate the pre- 
sence of marcasite. 

The radial canals are nearly all filled with pyrites, but some 
for a short distance remain vacant, running straight across the 
wall. The skeleton has disappeared; its traces remain as hollow 
casts, which are only visible here and there; they may be distin- 
guished from accidental cracks by their parallel-sidedness, rounded 
surface, and sometimes by their regular rectangular cross-like form. 

I believe this is the first instance not only of the description of 
a fossil sponge from the Gault, but of the observation of traces of 
skeletal remains in a wholly pyritized specimen. 


[For Explanation of Plate, see next page. | 


446 Scientific Proceedings, Royal Dublin Society. 


EXPLANATION OF PLATE XXII. 


Figs. 1 to 8—Illustrations of Craticularia calathus. 
Fig. 1.—Hollow casts of fragments of hexactinellid 
network, seen by reflected light. Obj. 1 
inch ; oc. No. 2. 
_ 2.—The sponge. Nat. size. 
3.—One half of the sponge, showing the oscules 
of the interior. 


99 


9) 


Figs. 4 to 5—Platychonia brodiet. 
Fig. 4.—Section through the sponge, showing the 

skeletal network. 

5.—One half of the sponge, showing a longitu- 
dinal median section. The highly shaded 
portion indicates the matrix, which partly 
fills up the interior of the sponge. 

,, 6.—The sponge. Nat. size. 


99 


( 447 ) 


LVII.—NOTES ON SOME POINTS IN THE CONSTRUCTION 
OF TURRET CLOCKS. By HOWARD GRUBB, M.E., 
E.R.S. 


[Read, March 16, 1885. ] 


A.rnoveH not exactly in my own line of work, I have lately had 
occasion to construct a turret clock, and having been thereby led 
to investigate somewhat closely the details of same, I beg leave to 
submit a few notes on those points in which I found it desirable to 
depart from the generally established lines. 

1st. Considering the care that is always taken by the best 
makers to preserve the going parts of the clock from all unneces- 
sary vibrations and shocks, by providing the most substantial foun- 
dation and isolating the clock supports from all floors, &c., it has 
always been a matter of surprise to me that they invariably, as far 
as | know, mount the “ going” and striking parts on the one frame 
or castings. In the act of striking, the frame receives violent blows 
from the hammer levers, far in excess of anything likely to occur 
from other causes, and as no attempt is made to isolate this neces- 
sarily heavy rough part of the work from the delicate going part, 
it appears to me that these concussions must exercise a very bad 
effect on the rate of the clock. 

T therefore have constructed the going and striking parts as 
entirely separate pieces of machinery, and they will be mounted 
on independent supports isolated from one another. The “ going” 
portion alone is exhibited here to-night. The striking portion is 
too large and heavy to bring down with any convenience. 

2nd. While my slight experience induces me to believe that 
Dennison’s (Sir E. Beckett) double three-legged gravity escape- — 
ment, which I have adopted in this case, is the very best for the 
purpose, I cannot believe with Sir EH. Beckett that it is so perfect 
that to add a remontoire train is superfluous, and I have therefore 
done so. 

Bearing in mind also that Sir H. Beckett himself says that 
the very best rate he ever knew in any clock is that at King’s 


448 Scientific Proceedings, Royal Dublin Society. 


Cross, London, which had an ordinary pin-wheel escapement with 
a remontoire train, I have so arranged the frame of this clock that 
I can in a few minutes replace the gravity by such a pin-wheel 
escapement. 

Sir E. Beckett justly observes that crucial experiments on the 
rate of a clock can only be conducted when the clock is erected in 
its own permanent position. , 

T have therefore made arrangements to enable this clock, when 
erected at Farmley, on the far side of Phoenix Park, to automati- 
cally report its rate daily to me in Rathmines, and hope by this 
means to be able to form in some months a fair estimate of the 
value of the different kinds of escapement. 

3rd. The remontoire fan usually applied to turret clocks, which 
has always appeared to me a very cumbersome and awkward piece 
of apparatus, I have replaced by a little fractional governor, simi- 
lar to what I use for equatorial clocks. 

I find this to work in a most satisfactory manner, and the whole 
apparatus is enclosed in a box two and a-half inches diameter, while 
the fan necessary to effect the same purpose would be at least two 
feet diameter. 

4th. I have replaced the usual ratchet, which makes such a 
disagreeable noise every one-third or one-half minute, by a pecu- 
liar silent click, which is perfectly effective and absolutely silent. 

In other respects the clock has no peculiar feature, except that 
its general arrangement is somewhat novel, and considering that 
it has to work two eleven feet exposed dials, and start the strik- 
ing part, which rings a peal of bells, the largest of two tons weight, — 
the escapement action is probably lighter than any hitherto made. 

The pendulum is a two-second pendulum. All the small pinion 
in clock train are lantern, the smallest being made on the principle 
described by me on a former occasion with reference to Siderial 
clocks. 

The “letting off” of the striking part is somewhat peculiar. 
The letting off cams are set up and placed in position by a slow 
moving shaft, but the final letting off is effected by a cam on a 
quick moving shaft, something after the manner of the Westmin- 
ster clock. 


449) | 


LVII.—NOTE ON THE PARTURITION OF A WEST-INDIAN 
BAT. By HENRY A. BLAKH, Governor or tHe Banamas. 


[Read, March 16, 1885.] 


On the 2nd June, 1884, when inspecting the caves on the western 
shore of New Providence Island with Mr. Maynard, an ornitholo- 
gist from Boston, and Mrs. Maynard, we observed the dome-like 
roof covered with pendent bats, of which there were about a 
thousand. We shot ten with our collecting guns, and on pick- 
ing them up we found that eight had young ones clinging to them. 
The eyes of one or two were open, though the down had not begun 
to form, but the remainder had the eyes still closed. On our return, 
when taking them out of the basket, I found that one of the full- 
grown bats was a female, apparently unwounded, but so heavy 
with young that it had fallen down with the concussion and been 
unable to rise. As I was informed that the manner in which bats 
were born had never yet been observed, and was a matter of scien- 
tific interest, I placed the bat in a box about eighteen inches high, 
with a glass front and wire top, and watched it closely. It hung 
to the top, where it remained all night. At noon on the 3rd, I 
observed that the exclusion of the young had commenced. The 
- bat had been hanging by one hind claw for several hours, the other 
being bent forward at right angles. There were regular labour 
paroxysms at intervals of about two minutes, lasting for about 
four or five seconds. Sometimes it hung by both claws, and bent 
back or forward, evidently suffering much. At 12.20 the left hind 
leg of the young bat entirely protruded, being doubled forward at 
the second joint. Almost the entire time the mother hung by the 
right hind claw, using the other to scrape from time to time the 
membranous sac in which the protruded leg was enveloped, or to 
scrape herself as a relief to the tension. As soon as the left lee of 
the young had been protruded the mother scraped the sac until it 
broke, when immediately the protruded leg was straightened and the 
claw grasped the integument of the mother’s “wing.” The latter 


| 


450 Scientific Proceedings, Royal Dublin Society. 


\ 
hung by the right leg, and bending the left forward, on this the 
free leg of the young was forthwith hooked. This evidently assisted 
the mother materially in its exclusion, as she gently raised the kent 
leg during the active periods of labour pains, thereby drawing the 
young one upwards. At 12.30 the other leg was free, and imme- 
diately both legs grasped the mother. At 12.35 it was completely ex- 
eluded, the back of the head to the front, so that at once it clung round 
the mother with wings and legs, The latter licked it all over, and con- 
tinued to do so for half an hour. The ears of the young bat were all 
this time folded flat on the head. The eyes were closed. The mother 
then began to bite at the umbilical cord by which it was still at- 
tached, resting at times as if exhausted. She continued this until 
half-past one, biting away small portions. At 3 p.m. the young 
was still attached by the umbilical cord, but was apparently suck- 
ing the mother. I was unable to observe anything further until 
10 p.m.,.when on looking at the bat I saw that the placenta had 
just come away and was being eaten by the mother, who let no- 
thing fall. ; 

Mr. Maynard, who examined the bats, stated that they were a 
variety hitherto undescribed. There were six of the young bats 
alive, and I had them fed with milk, which they sucked from the 
finger. However, they all died. On Wednesday, 4th June, the bat 
whose birth I had observed died. It was evidently trying to obtain 
nourishment from the mother, but was unable to’do so. Some- 
times it seized the mother’s wing—sometimes close to the vent. 
The mother seemed unable to place it on the teat; indeed, it 
grasped so tightly and with such pertinacity that the mother could 
not move it from any position in which it chose to place itself, 
On one occasion it seized the mother’s ear, and there it remained 
for an hour. After its death the mother adopted one of the other 
young ones, but it died also. J examined the mother most care- 
fully, but could not find a vestige of a teat anywhere. She is still 
alive, and eats sapodillo pears greedily. The head of the young is 
singularly like a pig. I have preserved a couple in spirits, which 
I shall forward to the Science and Art Museum, Dublin. 

So far as I know, the bat is the only mammal produced with 
the hind feet first presented. The manner of its birth is a singu- 
larly interesting illustration of the modifications effected by Nature 
to meet peculiar conditions. 


pao] 


LIX.— REMARKS ON THE GAMETOPHORE OR OOPHORE 
STAGE OF VEGETABLE METAGENKESIS. By 
PROFESSOR W. R. M‘NAB, M.D., F.L.8., &c. 


[Read, April 20, 1885. ] 


In the English edition of Sachs’ Teat-Book of Botany the two 
stages of the Alternation of Generations in plants are denomi- 
nated the Sporophore and the Oophore, respectively ; the former 
being the spore-forming generation, the latter the sexual stage. 
While the term sporophore accurately expresses the conditions in 
the one stage, the term oophore is only applicable to one of the 
sexual forms, and is, therefore, open to objection, although that 
one happens to be the more important of the two. In view of the 
great importance of having an intelligible and easily applied series 
of names for the reproductive organs of plants, it is advisable to 
re-consider the whole matter, and the reasons for doing so are all 
the more cogent because recently the subject of the sexual repro- 
duction of the lower plants has received a great deal of attention, 
and several new terms have been coined. No general set of terms 
has as yet been agreed upon by botanists; and as the reproductive 
organs have the greatest possible diversity of origin and construc- 
tion, very many names have been used, limited to special cases, 
but none of general applicability. Sachs has well pointed out that 
in the case of the vegetative organs of plants there is the same 
plan of construction associated with the utmost diversity of func- 
tion; but that in the reproductive organs this is reversed, and 
identity of function is attended with great diversity of structure 
and mode of origin (Sachs, Vorlesungen, p. 886). 

The term gamete has been long employed to signify the sexual 
cells of the lower forms of plants, and, by continuing to use this 
term, we can by prefixing andro- and gyno- indicate the male and 
female reproductive elements as androgametes and gynogametes. 
These terms seem to me to be very much to be preferred to those 
used by Sachs, namely “zoosperms” and “egg-cells”’ ( Vorlesungen, 
p- 887); because in many cases the male element is not a “ zoo- 


452 Scientific Proceedings, Royal Dublin Society. 


sperm” comparable with a spermatozoid, and the female cell is not 
always an “‘ oosphere.’ 

Tf, then, we accept the terms “‘androgamete” and “ gyno- 
gamete,” the union of the two can be defined as “ zygosis,” and the 
product a “zygote” or “ovum,” both these latter terms being al- 
ready accepted by botanists. We can thus indicate the essential 
part of the sexual process—the union of the male and female ele- 
ments, protoplasm with protoplasm, and nucleus with nucleus—as 
zygosis; and we can easily distinguish any preliminary steps in 
the whole process of fertilisation; as, for example, in the higher 
flowering plants, where pollination, or application of the pollen, 
precedes the process of zygosis, if the actual fusion of the repro- 
ductive elements can be held to occur in all cases. It is important 
to note that the term “ ovum” must be regarded as the exact equi- 
valent of zygote, the ovum being the new cell formed by the union 
or conjugation of one or more androgametes and the gynogamete. 

Passing one step further, we may now indicate the cases in 
which the male and female sexual elements are formed as the 
gametangia, a term already used and adopted, and we can at once 
distinguish between the androgametangia and the gynogametangia. 
The structure of these two organs varies very much, and we have - 
the antheridium as the typical androgametangium, and the arche- 
gonium as the typical gynogametangium. Sachs (Vorlesungen, 
'p. 887) proposes to use the terms “spermogonia”’ for the male 
organs, and “oogonia” for the female; but both these terms are 
quite inadmissible, the word spermogonium having been applied to 
special structures in the Fungi and Lichens, which are now known 
to be non-sexual, and the word oogonium is in common use, and is 
merely a rudimentary archegonium. 

Ii we now take the plant that bears the gametangzia, it is easy 
to denominate it the gametophore (a term I have now used for some 
time); and in such instances as in the prothalli of Hquisetum, where 
the male and female organs are produced on different plants, the 
two plants can be called the androgametophore and the gynogameto- 
phore, respectively. 

As we can thus obtain a perfectly consistent set of terms, with- 
out really adding to the burden of botanical terminology, I would 
strongly urge the rejection of Mr. Dyer’s term “ oophore,” as it 
is only applicable to the plant bearing the fertilised ovum. 


M‘Nas—Remarks on Stages of Vegetable Metagenesis. 458 


It will further be seen that for the non-sexual stage we have 
now in use a set of terms—spore, sporangium, sporophore—terms 
universally accepted, and the words gamete, gametangium, game- 
tophore, would, if adopted, at once indicate a similar series of re- 
lationships in the sexual stage of development. 

But we can advance one step further, and distinguish between 
reproduction by spores and reproduction by buds, and attempt to 
solve that most difficult botanical question, as to what is a spore. 
It is quite obvious that the spore must be associated with a spore- 
case or sporangium, and in all instances in which several spores 
originate in a spore-case no difficulty can arise, and there can be 
no such things as endoconidia. It is, however, quite different 
when only one spore is produced in a spore-case; but here we in- 
variably find that the spore either develops a special wall inside 
the wall of the sporangium, or else the spore escapes as a naked 
mass of protoplasm, and only develops a wall at a later stage. 
Now, if we apply this character to many of the reproductive bodies 
of the lower plants, we find that the different forms of conidia are 
all single detachable cells, without that inner wall which would 
indicate the formation of a spore inside a sporangium. Conidia 
are thus buds which become detached from the parent plant. 
Usually among the Fungi both spores and conidia are formed, 
there being often several kinds of conidia developed by one plant. 
As gamogenesis is exceedingly rare in Fungi, the reproduction is 
either by spores or conidia, or by both, as in most of the Ascomy- 
cetes. A question will arise as to the so-called spores of the Basi- 
diomycetes. As they arise like conidia,’ and produce no special 
internal wall inside the special swelling of the end of the sterig- 
mata of the basidium, I believe we must regard them as a group 
of Fungi which have lost the power of producing spores and only 
multiply by conidia. This is the last step in development in the 
Fungi, as it is only in the lower forms that sexual reproduction 
exists, and even in them apogamy or parthenogenesis becomes 
marked. ‘Thus true alternation of generations ceases and we have 
multiplication by spores or by conidia, the conidia alone remaining 
(Basidiomycetes) ; or the spores are only produced under excep- 
tional conditions, as in Penicillium and other Ascomycetes. 


1 See Vines. Prantl’s Text-Book of Botany, p. 141. 


SCIEN. PROC. R.D.S.—VOL. IV. PT. VIII. 2Q 


454 Scientific Proceedings, Royal Dublin Society. 


All these modes of non-sexual generation which cannot be 
included under the head of sporogenesis I would distinguish as 
blastogenesis, and the special reproductive bodies as blastidules. 
These blastidules are very varied, and appear as conidia, propa- 
gula, gemmae, buds, or even as fragments of a large plant. 

The reproduction of plants is thus of two kinds:—1, gamo- 
‘genesis, or sexual reproduction; and 2, agamogenesis, or non- 
sexual reproduction. Agamogenesis appears under two forms— 
namely, sporogenesis and blastogenesis, and when there is meta- 
genesis, or alternation of generations, it 1s an alternation of gamo- 
genesis and sporogenesis. Blastogenesis may occur both in the 
sporophore and gametophore stage, and numerous examples might 
be given. Then gamogenesis may be absent, and the plant may 
reproduce by sporogenesis or by blastogenesis, as in most Fungi. 

Lastly, as we have in such forms as Ulothrix and others mul- 
tiplication sometimes by gamogenesis, sometimes by agamogenesis, 
the sexual cells which have failed to form zygotes often developing 
by themselves non-sexually, thus giving us intermediate forms 
between sexual cells and spores; so we may expect to find that 
there are intermediates between spores and blastidules. 


5504 


LX.—ON DE ROSSI’S SEISMICAL AND ENDODYNAMICAL 
MAP OF ITALY. By PROFESSOR J. P. O'REILLY, 
C.H., M. RI. A. 


[Read, May 15, 1885.] 


Ir would not be too much to say that the particular branch of 
geology which deals with the forces acting from within the earth’s 
surface, and tending to modify it, has assumed within late years a 
very great importance; so much so, that under the name of Seis- 
mology, Dynamic Geology, Endodynamic Geology, it has attained. 
the rank of a specialty in connexion with Geology, and has led to 
observations and methods of observation of the very highest inte- 
rest and importance. In Germany, in Switzerland, in Italy, in 
America, and in Japan, societies have been formed mainly for the 
study of phenomena coming under this head, and certain of their 
results seem to me well worthy of being more generally made 
known. 

The full value of the earthquake as a factor in Geology can hardly 
be considered as having yet reached a clear and distinct recogni- 
tion. So many things in this phenomenon have to be accounted 
for, and their systematic observation is attended with such great 
difficulties, and even dangers, that such incomplete recognition of 
their importance can easily be explained. Besides, earthquakes, up 
to the present at least, can hardly be foreseen, or only exception- 
ally, as in the case of the neighbourhoods of Vesuvius and Etna, 
where seismic observatories are established and under the conduct 
of skilled observers. That there are premonitory indications in 
nearly every case is to be presumed; but as regards the great 
majority of recorded shocks, data of this character are wanting. 
And yet the consequences of earthquakes are such that the very 
greatest interest attaches to the correct observation and interpre- 
tation of the phenomena which precede them, and which, rightly 
read, are capable of serving as indications of a coming shock. 

Palmieri at Naples, and De Rossi at Rome, have long occu- 


456 Scientific Proceedings, Royal Dublin Society. 


pied themselves with this question ; and De Rossi, in a very remark- 
able address, delivered before the Geographical Society of Rome, in 
February, 1882, on his then projected seismical and endodynami- 
cal map of Italy, enters into very interesting considerations on this 
point, to some of which I shall take occasion to call attention. 

One of the most frequently-cited observations in connexion 
with earthquakes, at least within the last century or so, is the state 
of the barometer before and after the shock. It is frequently re- 
corded that the barometer was low before the earthquake cited, and 
a sudden fall has come to be construed, at least for certain locali- 
ties, as an indication of an impending shock. Such an interpreta- 
tion of the fall necessarily implies a connexion or relation between 
the atmospheric pressure at the place considered and the state of 
equilibrium of the tensions existing in the constituent matter of 
the earth underneath that place. Are there any grounds'for assum- 
ing the general existence of such a relation? I believe there are. 
The atmospheric pressure at any one place is simply the measure of 
the attraction exercised by gravity on the atmosphere at the place ; 
that is, by the mass of the earth. Any variation in the distribu- 
tion or arrangement of this must in some sort alter the position of 
the centre of gravity of the earth, however minutely, and should 
have, as consequence, a corresponding alteration in the amount 
and direction of the attraction exercised on the atmosphere, and 
therefore in the atmospheric pressure over different parts of the 
surface of the earth. Now, tensions which exist under a given 
surface, and which increasing and tending to reach a limit, and 
therefore of a nature capable of giving rise to an earthquake, must 
affect the arrangement of the matter of the earth under that sur- 
face, and pro tanto are capable of affecting the attraction of the 
earth for the atmosphere at the place considered, and consequently 
the pressures. 

But, even admitting this relation, the difficulty lies in the 
measurement of the amount of pressure attributable solely to 
alteration in the amount of attraction exercised at a given point 
of the earth’s surface. We have but one instrument for estimating 
atmospheric pressure, that is, the barometer, and it really only 
gives us the resultant of a// the forces, whatever they may be, which 
act on the atmosphere at the point of observation, without diseri- 
mination of the components. Furthermore, when a barometric 


O’REtity—De Rossi’s Seismical and Endodynamical Map. 457 


observation is made, it is always assumed that the atmosphere is in 
a normal state as regards its constitution, at least for those alti- 
tudes of which we have some knowledge. But that is simply 
assumption, and the constitution may be abnormal at a given time 
and for a given locality; and that such frequently occurs imme- 
diately before earthquakes may be gathered from some of the facts 
recorded as having preceded many earthquakes, and which have 
not, perhaps, received the full amount of attention which they 
merit. Thus there is frequently made mention of indications of 
uneasiness, more or less marked, on the part of certain classes of 
animals, more particularly of those which, by reason of their size 
or their habits, are naturally brought into close contact with the 
earth, such as small quadrupeds, fowl, cats, dogs, snakes, &e. Now 
this may fairly and reasonably be attributed to the emission of 
gases of a nature hurtful to such animal life, such as carbonic acid, 
certain carbides of hydrogen, hydrogen itself, or even sulphuretted 
hydrogen, all which are intimately associated with volcanic and 
seismic manifestations. This view is strengthened by the frequent 
alterations reported as occurring before earthquakes in springs and 
streams, such as their drying up or disappearing by reason of joints 
or fissures presenting an easy escape for gases which may be im- 
prisoned in depths, and the excessive pressure of which is a main 
cause of many if not of most earthquakes. How long before the 
earthquake may such escapes of gas have been going on on a minute 
scale, hardly, if at all noticeable, is a question of much interest, and 
would point to the importance to be attached to the careful exami- 
nation of the waters of springs, particularly if they have their 
sources in districts at all affected by earthquakes. The well-known 
variations in the volume and temperature of already existing hot- 
springs consequent on earthquakes justify this pomt of view as 
well as the equally well-established 16/e of these in giving rise to 
such springs. We can thus see that there is an intimate relation 
to be recognised between earthquake action and emission of gases, 
and between these and fissuring or jointing. Now, the tendency of 
all recent seismical research and observation is to connect earth- 
quake action with the existence of systems of joimting and fissur- 
ing. And thus we have a relation established between these 
emissions of gases and earthquakes. But such gases, by reason of 
their specific densities and temperatures of emission, influence more 


458 Scientific Proceedings, Royal Dublin Society. 


or less the barometric pressure at the place of their source. Of small 
quantities given off probably no account could be taken, since 
their influence on the barometer would be insignificant; but for 
great quantities of gases given off the effect would be all the more 
marked, proportionally to the volume, temperature, power of dila- 
tation, and lowness density of such gases, since ascendant currents 
must then arise with consequent fall in the barometer. Therefore 
there may be cases where a fall in the barometer would really and 
truly serve as an indication of an impending earthquake, but would 
also imply an escape of gases on a very large scale. This con- 
nexion goes far to explain also many manifestations frequently 
recorded as following on or accompanying earthquakes, such as 
sudden whirlwinds or local storms, great electrical tension and 
display of lightning, balls of fire or meteors, and even the so fre- 
quently-mentioned seasons of disease or bad harvests, since great 
quantities of noxious gases thus poured out from the earth would 
necessarily saturate the pores of the earth, be retained there, and 
consequently influence both vegetable and animal life, We know 
little yet as to the constitution of the atmosphere at heights such 
as 10,000 m. above the sea level, or even, indeed, between 8000 
and 10,000 m.; but it has been distinctly ascertained that the 
quantity of ammonia increases with height, while the carbonic acid 
decreases ; and we may therefore assume that hydrogen and the 
volatile carbides of hydrogen increase in quantity also with height 
where they are subjected to the action of electricity and solar action, 
giving rise thus to combinations accompanied by emissions of light 
such as to present the appearances of meteors. Is there not some 
similarity between the conditions presented by the highly rarified 
atmosphere at those heights and those presented by the vacuum 
tubes experimented on by Crookes, by means of electrical currents P 

This idea of foreseeing earthquakes, by the careful observation 
of all the phenomena connected with them, is one involved in 
De Rossi’s proposed seismical and endodynamical map of Italy. 
In the address alluded to he commences by calling attention to 
one of the results of his studies, that is, “that we always find a 
certain identity as regards the manner and the quality or energy of 
action of all the earthquakes which in the course of time have af- 
fected or affect a given locality ; whence follows the possibility of 
affirming that with the aid of certain geological and orographical 


O’Rutty—De Rossi’s Seismical and Endodynamical Map. 459 


observations, the seismical topography of any district may be 
traced out beforehand.’ Further on he says: “The want of a 
seismical and endodynamical map of Italy soon made itself felt, 
once the new methods of seismical study were initiated, and which 
consist essentially in a great chronological and topographical co- 
ordination of the history of the dynamo-geological phenomena 
having affected our country, and in a similar co-ordination of the 
continuous observations made of the sensible as well as insensible 
manifestations of internal dynamic action.” 

He alludes to the maps which have been frequently published, 
showing the actions of earthquakes in certain countries and dis- 
tricts, and states: “One thing alone constantly appears on these 
maps, the perimeter of the surfaces shaken always presents an 
elliptical form. My manner of understanding this elliptical form 
of the area shaken,” he says, “is that the centre of percussion 
tends to assume a lineal form; or, as Serpiéri so well expresses it, 
the seismical centre assumes the form of a radiant (radiante). 
This radiant would consequently be the major axis of the ellipsis.” 

He calls attention to Ponzi’s studies “as pointing to the tact 
that geological iractures of the earth (swolo) are the means of 
communication of the endogenous cause of earthquakes, and act 
as lines of interruption to the uniform propagation of the seismi- 
cal wave.” 

Wishing to verify by actual observation the truth of this result, 
he took occasion to map out the effects of the earthquakes which 
affected the country near Rome in January, 1873, “ wishing to 
profit by the occasion to make an accurate study of the relations 
which came to be established between the well-defined geological 
fractures of the volcanic system of the district and the form otf the 
earthquakes having occurred. I saw that in each case it was evi- 
dent that the fracture had acted as a seismical radiant, and that 
by tracing out the map of the volcanic fractures I at the same 
time traced the axes of propagation of the seismic undulations. It - 
was then that I formulated the mechanical law of earthquakes, 
well known to all, according to which the seismical wave is, in any 
given country, always first parallel and then normal to the axis 
of the nearest system of geological fissuring (secondo la quale 
l’onda seismica in ciascuna contrada é mai sempre parallela prima, 
e poscia normale all’asse della fenditura geologica piu vicina). 


460 Scientific Proceedings, Royal Dublin Society. 


Whence I formulated the axiom, never sufficiently repeated, be- 
cause it is the basis of the new architectonic precepts preservative 
against the action of earthquakes— The shock communicated to a line 
of fracture is followed by the transverse oscillation of its sides or 
margins.” : 

Serpieri took advantage of the great earthquake of 12th March, 
1873, to thoroughly control the observations of De Rossi, and the 
result was the most complete confirmation of the laws established 
by De Rossi on the propagation of earthquakes by the fractures 
with waves parallel and normal to the axis of the systems of frac- 
ture. 

This earthquake of 12th March, 1873, was mapped by Captain _ 
Gatta, and from this map there resulted “that the central zone 
coincided with a long lineal tract of the axial crest of the Apen- 
nines, and that the arrows (of direction of wave) parting all from 
this crest, assumed directions along the two slopes parallel to the 
axes of all the valleys of the rivers. It is a most notable thing 
that nearly all the valleys of the Apennines are thus shown to be 
geological fissures dividing the masses of the mountain chain.” 

Further on he says: “The fissures of the earth wherever met 
with represent a series of obscisses and ordinates. It is clear that 
where the seismical agent breaks out it should propagate itself 
with greatest violence and rapidity in the direction of the fissure 
that it penetrates.” Thence it propagates itself into the lateral 
fissures, which thus become derived or secondary radiants. So that 
im some sort the zone affected presents somewhat the appearance of 
the backbone of a fish with the spines, “round which if a peri- 
meter be traced it assumes the form of an ellipsis.” 

“My map (p. 8), although very imperfect, shows a system of 
coicidences between the geological fissures and the seismical radi- 
ants which cannot be fortuitous, and which, therefore, is in itself a 
demonstration of its scientific truth.” 

“Tt has been already shown that my seismical map is equivalent 
to a map of the geological fractures or fissures; but it may be observed 
that it is at the same time in some sort a hydrographical map of 
Italy. Whence it follows that the main lines of the geological 
and orographical structure of Italy, of its hydrography and its 
seismical lines of works, become identified, or at least are brought 
into very close connexion.” 


O’ Rurmty—De Rossi’s Seismical and “ndodynamical Map. 461 


He considers (p. 9) that the seismical map is not sufficient for 
the objects of his studies, which must be extended to all the phe- 
nomena having an origin internal to the surface of the earth, in 
order “to prepare from them a synthesis which will reveal the 
secrets of telluric dynamics—of that telluric dynamics up to the 
present so very little studied and not at all known, although it 
covers So many menaces for our very existence as well as innume- 
rable aids to our prosperity.” 

Speaking of Pella’s definition of an earthquake as an attempt, 
or unsuccessful effort of eruption from the interior of the earth, 
he says: “Asa matter of fact, there never is a volcanic eruption 
without earthquakes, nor is there an earthquake, even in non- 
voleanic regions, without eruption or at least emission of gases and 
vapours.” 

Having alluded to microseismical movements and their micro- 
eruptions, he says: “In one word, the subterranean circulation of 
water is to be considered as a factor of the first importance in the 
incessant labour of the internal agents of the globe.” 

Speaking (p. 12) of the method which he proposes to employ 
for the co-ordination of his work :—“ The system of division, the 
best appropriated to the scope of my undertaking, is that of con- 
sidering separately the hydrographic basins of Italy. This divi- 
sion, from what has been already explained, leads mechanically, 
so to speak, to tracing out the network of the fissures and of the 
seismic radiants, and to defining the axes of the valleys, along 
which will be found the secondary manifestations of activity, the 
thermal springs of the present, and the geological traces of a telluric 
action which has ceased to show itself.” | 

He shows (p. 18) that the surface hydrography of the country 
is intimately connected with internal telluric action, and adds: “Ii 
the valleys are in the most cases fissures of the earth’s crust (swolo) — 
they must, consequently, be the passages by which absorption of 
the surface waters takes place, so as to reach directly the internal 
laboratories and join the subterranean system of circulation.” 

Alluding (p. 14) to the frequency of earthquakes in and about 
the Lago di Garda, he states: “‘Ihe most recent geological re- 
searches have demonstrated that the lake is an immense geological 
fissure. .The courses of the great rivers are very frequently the 
_ axes of earthquake shocks. Whence,” he says, “the study of the 
2K 


SCIEN. PKOC, K.D.S.-—VOL. 1V. PT. VIII. 


462 Scientific Proceedings, Royal Dublin Society. 


hydrography of a country is equivalent to the study of what may be 
called the keys of the internal telluric activity.” He adds (p. 15): - 
‘‘The tempests and the extraordinary storms, the centres of baro- 
metric depressions which have sojourned more or less in a river- 
basin, will be found to be phenomena proper to each particular 
basin, and capable of influencing its endogenous activity.” 

Referring to the importance to be attached to the examination 
of precipices and cliffs as connected with fissuring, and thus with 
former earthquake-action, he says (p. 15): “ Taramelli with good 
reasons thinks that in a post-glacial epoch, but pre-historical, the 
surface of Italy was subjected to an extraordinary endogenous 
activity and to seismical convulsions far greater than those known 
or recorded in historical times, and that at that period were pro- 
duced the great fracturings, having giving rise to clifis, and the 
consequent incumbering of the valleys of fracture with detritus, 
and to alterations in the regimen of the hydrographical basins.” 

With these phenomena he connects that of the formation of 
travertine, and considers that both together point to an immense 
development of endogenous activity during the post-glacial period, 
which also was that of the littoral voleanoes of Italy ; so that the 
littoral vuleanism and its secondary and inland manifestations | 
correspond to a same geological era. 


[ 463 ] 


LXI.—ON THE STRUCTURE OF THE FLOWER OF BON4- 
TEA SPECIOSA, WILLD. By W. R. M‘NAB, M.D., 
F'.L.8., Professor of Botany, Royal College of Science, 
Scientific Superintendent of the Royal Botanic Garden, 
Glasnevin; and Consulting Botanist to the Royal Dublin 
Society. 


[Read, May 18, 1885.] 


On the 29th of April, 1885, Mr. F. W. Moore directed my atten- 
tion to a plant of Bonatea speciosa, Willd, then in flower at the 
Royal Botanic Garden, Glasnevin. The plant is a native of the 
Cape of Good Hope, and the specimen in the Glasnevin Garden was 
obtained from the Leyden Botanic Garden in 1883. As the flower 
was evidently one of great interest, Mr. Moore kindly sacrificed the 
whole spike, and I have since examined the structure carefully. On 
making a direct examination of the flower, without having consulted 
any book or paper on the subject, I came to the conclusion that in 
the flower of Bonatea speciosa all the typical parts of a monocoty- 
ledonous flower were represented, and that therefore the plant was 
one of singular interest. The three parts of the calyx, the three 
petals, were present as usual, as well as the one fertile stamen of 
the outer row. But, in addition, there were two petal-like struc- 
tures, but more conspicuous than the petals, and these I at once 
considered to be petaloid staminodes. Next, two gland-like struc- 
tures attracted my attention, at the base of the staminodes, and 
these were put down as representing two of the inner row of sta- 
mens, aud a conical fleshy projection on the labellum immediately 
in front of the spur completed the inner series of stamens. The 
rostellum and two fertile styles and stigmas projected outwards 
over the labellum, and thus completed the flower. 

Bonatea speciosa was carefully studied by Darwin from dried 
specimens (see Fertilization of Orchids, p. 302, et seg.), and he con- 
siders Bonatea to be an exception in regard to its structure; but he 
considers the wide separation of the anther cells to be the cause of 
the distortion. He also holds the view of all descriptive botanists, 
that the lateral petals are cleft into two. Further, he points out 


SCIEN. PROC. R.D.S.—VOL. IV. PT. IX. 28 


& 


464 Scientific Proceedings, Royal Dublin Society. 


two anomalies in the supply of the vessels to the different parts. 
Those are: first, that the vessels which supply the sides of the 
upper sepal enter the postero-lateral or paired petal bundles; and, 
secondly, that the vessels to the anterior side of the upper petals 
enter the antero-lateral or paired sepal groups. 

I have examined both longitudinal sections of the flowers ren- 
dered transparent, and a consecutive series of transverse sections, 
and I am able to confirm Mr. Darwin’s statement that the lateral 
sepaline bundles join the paired petal bundles. Ramification of 
the sepal bundles occurs, while the ultimate paired petal bundle 
remains unchanged after giving off the bundle to the sepal. It 
seems remarkable that the position of the bundle of vessels to 
the so-called anterior parts of the upper or paired petals should 
not have led Mr. Darwin to consider the structures to be staminodes, 
as they are in the proper position. 

I can trace no vestige of bundles to the three rudimentary 
stamens of the inner row, if such they be, although I have spe- 
cially searched for them. 

In making sections of the inferior ovary, six bundles can be 
observed—three corresponding to the placentas and three alternat- 
ing with them. Two of the placental bundles have each three minute 
bundles on their inner side, and the third, corresponding to the 
labellum, has two large bundles. These eight small bundles quite 
disappear in the upper part of the ovary, and the shortest placenta 
is that corresponding to the position of the labellum. We thus have 
in this Orchid flower three bundles which have to supply the pla- 
centas, and three that do not. The bundles supplying the pla- 
centas must be called upon to supply water and much nutrient 
matter to the growing ovules, and their development in the flower 
above must be hindered. Hence, as they correspond to the petals, 
the petals will be feeble in Orchid flowers, and the stamens super- 
posed to the petals more or less completely wanting. On the other 
hand, the sepaline bundles are well developed, and they give off 
bundles to the fertile stamens and lobes of the stigma, the bundles 
to the stigmas being given off very early before those to the lateral 
stamens. ‘The Orchid flower is much developed anteriorly and pos- 
teriorly; but the posterior petal, the labellum, cannot get much 
nourishment from a bundle which has to supply the placenta, and 
therefore its supply must be supplemented. In the leaves of mono- 


M‘Nas—On the Structure of the Flower of Bonatea speciosa. 465 


cotyledons the bundles entering the leaf are directly proportional to 
the circumference of stem occupied by the leaves, and to the number 
of bundles in the stem. In the Orchid ovary the posterior part is 
flattened in Bonatea, and this evidently permits an additional supply 
of nourishment to be obtained from the more vigorous lateral sepa- 
line bundles, the petaline bundles not even being able to send off 
a filament to the extremely reduced structures in the flower which 
obviously represent two at least of the inner verticil of stamens. 
Thus, many of the peculiarities of the Orchid flower probably de- 
pend upon the vascular supply, and this subject is one that will 
certainly well repay further careful. research. 

The flower of Bonatea speciosa is well described and figured by 
Mr. Roland Trimen, in Jowr. Linn. Soc., vol. ix., p. 156; but he 
gives no critical remarks on the structure of the flower. 


282 


f Aaa). 


LXIJ.—ON APOSPORY IN THE THALLOPHYTA. By W. R. 
M‘NAB, M.D., F.L.8.; Professor of Botany, Royal College 
of Science; Scientific Superintendent of the Royal Botanic 
Garden, Glasnevin ; and Consultmg Botanist to the Royal 
Dublin Society. 


[Read, May 18, 1885. ] 


Mr. Druery’s remarkable discovery of Apospory (Journal of Linn. 
Soc., vol. xxi., pp. 354, 358, and 360) may help to explain certain 
peculiarities observed in the Peronosporez and also in Vaucheria. 
As apogamy is not limited to the higher plants, it is therefore most 
natural to expect the occurrence of apospory in the Thallophyta. 
As apospory seems to be a very peculiar change occurring only 
under certain special conditions, it is not to be expected that the 
process will be common in the Thallophyta; and the two sets of 
examples here brought forward as apospory are both met with in 
highly specialized non-cellular plants, the one being a green Alga, 
the other instances being from a remarkable group of parasitic 
Fungi. . 

In Cystopus candidus there is produced below the epidermis of 
its host a moniliform series of cells, and the cells of this series may 
become separate when mature. These cells are almost always 
described as conidia. Van Tieghem (Zratte de Botanique, p. 1021) 
simply calls them spores, while Vines in the fourth edition of 
Prantl’s Botany calls them sporangia. ‘That they cannot be coni- 
dia is abundantly evident from the fact that the contents escape 
as ciliated zoospores; while conidia seem always to germinate di- 
rectly, by sending out one or more tubular prolongations. By 
comparing the closely allied genus Achlya with Cystopus, the 
necessary proof seems to be obtained of the identity of the zoo- 
sporangia of Achlya with the so-called conidia or spores of Cysto- 
pus. ‘I'he single terminal bodies of Peronospora, and the some- 
what similar bodies in Phytophthora may also be regarded as true 
sporangia, although there is a special peculiarity in Cystopus; 
namely, that the sporangia are superposed to one another in a 


M‘Nas—On Apospory in the Thallophyta. 467 


moniliform series, a condition which, however, is also met with in 
the allied Monoblepharis polymorpha. 

We may therefore regard the so-called conidia or spores in the 
Peronosporeze as detachable sporangia, dissociation of the sporan- 
gium and sporophore being of importance in the scattering of the 
ciliated zoospores which takes place under favourable conditions. 
Many modifications occur in the formation of the zoospores, as 
fully described by Van Tieghem (Traite de Botanique, p. 1022), 
and while in many instances zoospores are normally produced, 
under other conditions they are always wanting: while in a third 
series zoospores may or may not be produced. When the spores 
are not produced, and direct development occurs, we have un- 
doubted examples of apospory. ‘This is best shown in Oystopus 
- portulace, and in Phytophthora infestans (Van Tieghem, Joc. cit.). 
In Cystopus portulace the first and oldest sporangium of the 
moniliform series behaves differently from the others of the same 
series. The lower ones all develope as sporangia, and liberate 
zoospores; but the upper one does not liberate its contents, and 
sending out hyphae, developes directly into a new thallus. This 
is an example of apospory. Phytophthora infestans exhibits 
apospory when the sporangia are grown in moist air, as hyphae 
are directly produced ; but zoospores are developed in the usual 
way when the same sporangia are placed in water. Lastly, in a 
number of species of Peronospora a single spore may be formed, 
and escape from the sporangium, after which it germinates in the 
usual way; or else the sporangium sends out hyphae, and the 
spore is suppressed. ‘This is seen in Peronospora gangliiformis 
P. parasitica and others: all of which are to be regarded as truly 
aposporous (see Van Tieghem, Tiaite de Botanique, p. 1022). 

In Vaucheria, where the structure is in many points remarkably 
like that ot the Peronosporez, no question has ever arisen as to 
the propriety of regarding as a sporangium the cell, cut off from 
the rest of a thallus by a transverse wall, in which the zoospore is 
formed. ‘There is in Vaucheria the most complete series of grada- 
tions, from the production of ciliated zoospores to spores which 
have no cilia, and do not leave the sporangium, to complete apos- 
pory in Vaucheria tuberosa. In this species all the phenomena 
associated with the formation of a sporangium are observed, but 
the isolated sporangium developes into a new thallus without 


468 Scientific Proceedings, Royal Dublin Society. 


giving rise to a spore (see Van Tieghem, Traite de Botunique, 
p. 11338). 

There seems to me to be some little difficulty in accepting 
Professor Bower’s statement that the artificial production of proto- 
nema and buds from cut pieces of the sporangium of certain 
mosses is an example of apospory (see Journal Linn. Soc., vol. xx1., 
p. 866). It much more closely resembles the production of conidia 
by certain Fungi under unfavourable conditions of growth, and is 
thus blastogenesis. No mosses seem to produce a leafy axis directly 
from a protonema developed by the ovum; but looking at the con- 
dition as possible, we may regard the development of the Characeze 
as exhibiting apospory ; and we can thus account for the absence 
of spores in this most remarkable group. In the Characez the 
fertilized ovum contains a rudimentary sporophore generation, 
which by apospory forms the prothallus and lateral bud from 
which the Chara plant arises. While thus regarding apospory as 
probably wanting in the Bryophyta, Chara may be looked upon 
as habitually aposporus. 

In Batrachospermum (Van Tieghem, Traite de Botanique, p. 
1185), where the spores (protospores, v. Th.) are suppressed, and 
the ovum gives rise directly to a protonema, we have also a pro- 
bable example of apospory, and an analogy indicated with Chara 
and the Bryophyta. 

The Peronospores, as we have just shown, exhibit apospory, 
and it is remarkable that the next group, the Saprolegnez, exhibit 
apogamy, direct development occurring in many of them without 
the female cell being fertilized by the male cell. If, therefore, 
we have direct development without the formation of spores (apos- 
pory), and direct development without the formation of the gyno- 
gametes (apogyny), may we not also have direct development to a 
limited extent of the male, the androgametophore or androgame- 
tangium stage, and thus have apandry? (lor further remarks on 
apandry and apogyny, see Van Tieghem, Zraite de Botanique, p. 
956.) If we regard the sexual stage of the plant merely as the 
oophore, we lose the significance of this development, where no 
androgametes are formed, and the androgametangium, or even the 
androgametophore, seems to develop directly. I would regard the 
remarkable development of the male reproductive stage in the 
pollen grain as apandry, and I would further consider that in the 


M‘Nas—On Apospory in the Thallophyta. 469 


Saprolegnew there is apandry where the antheridium fuses with the 
oogonium, and no androgometes are formed (Achlya, Saprolegnez, 
Aphanomyces). Those remarkable parasitic Fungi, the Perono- 
spores and Saprolegnes, are examples of apospory and apogamy, 
in its two forms apandry and apogyny. 

Itis possible that in such a plant as Ulothrix, where the gametes 
are similar, and where, as Dodel-Port! has shown, the gametes may 
develop directly without conjugating, both apandry and apo- 

vyny may be present. Indeed the whole subject of reproduction 
will require to be reconsidered in the light of such discoveries as 
those of apospory and apogamy. 

Lastly, Professor Bower (Jowrnal Lin. Soe., loc. cit.) mentions 
the remarkable development of buds in Isoetes as an example of 
apospory. It appears to me that this process is more closely re- 
lated to the production of buds in Lycopodium selago. The pro- 
duction of buds in Lycopodium is a remarkable process admitting 
of several variations; and it is at present very difficult to separate 
apospory from ordinary budding, leaves being so often sporophylla. 


1 Jahrb fur wiss. Bot. x., 1876. 


[ 470) 


LXIII.—_THE DISTRIBUTION OF THE STARS IN SPACE. 
By W. H. 8. MONCK. 


[Read, May 18, 1885.] 


Tat the fixed stars are not uniformly distributed in space is a 
fact too obvious to insist upon; but, nevertheless, I believe some 
important consequences may be derived from tracing the re- 
sults of an uniform distribution, and then comparing these with 
the results of observation, and pointing out where the most re- 
markable deviations take place. 

Supposing the stars to be all of equal absolute brightness, and 
to be situated at equal distances from each other throughout all 
space, it will appear that if we describe a sphere with the earth as 
centre, the light of the stars which intersect or touch this sphere 
will be a constant quantity ; for the number of stars which inter- 
sect or touch the sphere will vary directly as the square of the 
radius, while the intensity of the light of each star will vary 
inversely as the square of the radius. This result will not be 
affected by giving to the surface of each sphere a small but uni- 
form thickness; and by adding together a number of such surfaces 
it becomes evident that the total light of the stars comprised 
within any sphere will vary directly as the radius of the sphere— 
this radius measuring the number of surfaces of which the sphere 
may be considered to be made up. But the number of stars com- 
prised within each sphere will evidently vary as the cube of the 
radius. If, taking any sphere as unit, we describe other spheres 
with twice, three times, four times, &c., its radius, the stars com- 
prised within these spheres will give twice, three times, four times, 
&e., the light of the stars comprised within the inner sphere; 
whence it follows that the stars comprised in the space included 
between any two adjacent spheres will give the same amount of 
light as that of the stars in the inner sphere. Since the total 
number of stars in each sphere is proportional to the cube of its 
radius, the number of stars in these interspheral spaces is easily 
calculated. Representing the number of stars in the inner sphere 


Moncx—The Distribution of the Stars in Space. 471 


as unity, the number in the successive interspheral spaces will be 
7, 19, 37, 61, &c., the general expression being (n + 1)? — n’. 
Hach of these sets of stars will (on the hypothesis of uniformity) 
give us the same amount of light. 

One obvious consequence follows from the foregoing considera- 
tions. If the radius of the sphere becomes infinite, the quantity 
of starlight becomes infinite also. Strictly, of course, this could 
not be true. One star would get in the way of another, and there 
are probably a number of dark bodies in space which would in- 
tercept some of the light without giving any themselves. But 
after making a very liberal allowance for this kind of obstruction, 
the entire sky ought to glow with a brightness exceeding that of 
the full moon. There seem to be but two possible reasons why 
something approaching to this state of things is not found to exist 
by observation. The first is, that all the stars belong to one vast 
system occupying a particular region of space, and that beyond 
this region there is a practical vacuum The other is, that there 
is some medium widely diffused through space which intercepts 
a portion of the starlight, and produces very sensible effects in the 
case of extremely remote stars. The motions of Encke’s comet afford 
some reason for believing in the existence of such a medium, and 
other reasons will, I think, appear before the close of the present 
Paper. 

If we suppose the inner sphere of which I have spoken to in- 
clude twenty stars, these stars will, on the hypothesis of unifor- 
mity, be the twenty stars of the first magnitude recognized by 
astronomers. The second, third, fourth, &c., sets will consist of 
140, 380, 740, &c., stars in the descending order of brightness, 
and the light given by each set of stars will be constant and equal 
to twenty, if we represent the average light of a first magnitude 
star as unity. Now, Dr. Ball, the Astronomer Royal of Ireland, 
in his Elements of Astronomy, has given us the number of stars 
of each magnitude from the first to the ninth, and also several 
determinations of the ratio of the light of the stars of any magni- 
tude to that of the magnitude next above it—a ratio which appears - 
to be nearly constant. This ratio has been variously determined, 
the figures ranging from 0°346 to 0:464. I take 0-4 as the mean, 
which cannot be far from the truth. The number of stars of each 
magnitude after the first are, according to Dr. Ball, second mag- 


472 Scientific Proceedings, Royal Dublin Society. 


nitude, 65; third magnitude, 190; fourth magnitude, 425; fifth 
magnitude, 1100; sixth magnitude, 3200; seventh magnitude, 
13,000; eighth magnitude, 40,000, and ninth magnitude, 142,000. 
Now, dividing the stars into sets which ought to give equal light 
on the hypothesis of uniformity, we can easily ascertain to what 
magnitudes the stars in each set belong; and multiplying the 
number of stars of any magnitude by the figure which represents 
the intensity of light for that magnitude, we obtain a result which 
shows in what direction the deviation from uniformity takes place. 
Thus the second set consists of 140 stars which will embrace the 
whole 65 second-magnitude stars, together with 75 stars of the 
third magnitude. If the average light of a star of the first mag- 
nitude is represented by 1, that of a second-magnitude star will be 
represented by 0-4, and of a third-magnitude star by 0:16. Hence 
the actual light of this second set will be represented by 65 x 0-4 
+75 x 0:16 or 38, whereas on the hypothesis of uniformity the 
value of the total light ought to be 20. There is, therefore, 
in this instance a very marked deviation in the direction of excess. 

Carrying on this computation I found that several successive 
sets will, in many instances, consist altogether of stars of the same 
magnitude. As the number of stars in each set is greater than 
in any preceding set, there would in such cases appear to be a con- 
tinual increase in the light if, in each case, I multiplied the num- 
ber in the set by the average intensity for that magnitude. But 
the smaller sets contain the brighter, and the larger sets the 
fainter stars of any given magnitude, and the apparent increase 
has therefore, in all probability, no foundation in fact. I have 
therefore thought it best to strike a general average for all such 
sets, without attempting to trace whether the total light increases 
or diminishes as we pass from the earlier to the later. This plan, 
however, is not available when a set includes stars of two different 
magnitudes; and it is evident that if it includes only a few of the 
fainter stars of one magnitude while it contains a large number 
of the brighter stars of the following magnitude, its total ight will 
be underrated on the principle of averages. When this state of 
things is reversed. the light will in like manner be overrated. I 
have applied the principle of averages throughout for want of 
a better, but I desire to state that the sudden increase of light at 
the tenth set, and the equally sudden diminution at the fifteenth 


Moncx—The Distribution of the Stars in Space. 473 


set, appear to be due to the causes which I have mentioned, and 
that I have no reason for believing that these sets present any 
abnormal characteristics. With this preface I give the following 
Table as the result of my computations :— 


Total light 

Ist set, 20 stars of the first magnitude 20 
2nd set, 65 2nd magnitude+ 75 38rd magnitude = 388 
drd set, 115 3rd magnitude + 265 4th magnitude = 35:4 
4th set, 160 4th magnitude + 580 Sth magnitude = 25-1 
5th set, 520 5th magnitude+ 700 6th magnitude = 20°5 
6th set, 1820 6th magnitude sae : 5 = ISG 
7th set, 680 6th magnitude + 1860 7th magnitude = 14:6 
8th set, 3380 7th magnitude 5 : : : 15°8 
9th set, 4340 7th magnitude 3 : : : 7 
10th set, 38420 7th magnitude + 2000 8th magnitude = 17:3 
11th set, 6620 8th magnitude : . ; : 
12th set, 7940 8th magnitude i : : 5 j 
13th set, 9380 8th magnitude : f = Eee 
14th set, 10940 8th magnitude 


15th set, 3420 8th magnitude + 9500 9th magnitude = 11:3 
16th set, 14420 9th magnitude : . : 

17th set, 16340 9th magnitude 
18th set, 18380 9th magnitude 
19th set, 20540 9th magnitude 
20th set, 22820 9th magnitude 
21st set, 25220 9th magnitude 


= 112¢ 


In this Table the second and third sets are largely in excess of what 
they ought to be on the assumption of uniformity, and the excess 
is partly carried on to the fourth set ; from whence it would appear 
that the stars of the second, third, and fourth magnitudes are 
much more numerous, comparatively speaking, than those of the 
first. We seem to be in fact traversing a comparatively barren 
region surrounded by regions much richer than itself—regions 
which our remote ancestors may have traversed, and which our 
remote descendants may traverse—regions I may add which may 
have left their impress behind them in those vestiges of the past 
which it is the province of the geologist to trace. But still more 
remarkable is the steady decline of the total light from the second 
set down to the twenty-first, beyond which my data did not suffer 
me to proceed. I have already given my reasons for not regarding 
the tenth and sixteenth sets as exceptions to this law, and the 
apparent deviation at the eighth set seems to admit of a similar 
explanation. Few astronomers will, I think, be of opinion that 


474 Scientific Proceedings, Royal Dublin Society. 


a steady thinning-out of the star-system sets in as early as the 
average distance of a star of the fourth magnitude; but I do not 
see on what other principle the results embraced in the foregoing 
Table can be explained unless it be the absorption of light by some 
interstellar medium. In the case of a star of the ninth magnitude 
I cannot estimate this absorption at less than one-third of its total 
light—probably more. At all events the aspect of star-distribution 
on which I have dwelt deserves more attention than it has hitherto 
received; and now that photographic measures of the intensity of 
the light of stars are being superadded to the photometric measures 
previously employed, more numerous and reliable results may ere 
long be expected. 

There are two other modes of regarding the problem which I 
may briefly notice. The first is:—We have seen that on the 
hypothesis of uniformity the 20 inner stars whose average light 
is 1 are succeeded by a set of 140 stars whose average light is 1; 
these by a third set of 8380 whose average light is ;5, and so on. 
Now, instead of dividing the stars into successive sets of 20, 140, 
380, &c., in order of brilliancy, and ascertaining whether their 
total light exceeds or falls short of the constant quantity supposed 
by our hypothesis, we may divide them into successive sets whose 
average light is 1, 1, =, &e., and examine whether the number of 
stars in each set exceeds or falls short of that given by the theory. 
I endeavoured to apply this method, and the results were rather 
singular. ‘The first set of course contains the 20 first-magnitude 
stars as before, but the second set, instead of containing 140, was 
found to contain no less than 508. After such a figure a deficiency 
in the succeeding set was perhaps to be expected. At all events 
it appeared, for the set only contained 245 stars while theory gave 
380. But when I came to the fourth set I found that it vanished 
altogether. Its average light is ;; but the third set, constructed 
on the present principle, terminated among the fifth magnitude 
stars, whose average brightness is between 345 and 75. It thus 
appeared as if all the stars whose light averaged 54 were required 
to balance the brighter stars of the third set, and bring down the 
average of that set to 745. Probably, however, the complete vanish- 
ing of the fourth set was illusory. The set commences in the 
first hundred of the 1100 stars of the fifth magnitude, and there 
can be little doubt that the brillianey at this stage exceeds 3b. 


Monex— The Distribution of the Stars in Space. 475 


But though the set does not vanish, it must contain a much smaller 
number of stars than the 740 afforded by the theory—probably not 
half that number. After such a check in the arithmetical compu- 
tation as this, I did not think it necessary to proceed any farther. 
The result, however, strikingly confirms my former conclusion as 
to the great richness of the region of stars immediately beyond that 
through which we are travelling. 

The third mode of looking at the problem would be much the 
most satisfactory if we possessed the requisite data for applying it, 
but unfortunately we do not, nor are we likely to do so for a very 
long period. ‘This method would consist in taking the 20 nearest 
stars as our first set; the 140 nearest to them as our second set; the 
080 next in point of nearness as the third set, and so on; and then 
to compare the light of the several sets as thus determined. But 
to go no farther than the first set, what astronomer would venture 
to specify the 20 stars.that are nearest to us? While, however, 
we thus lack the requisite data, we can see in a general way the 
kind of effect that would be produced by substituting the nearest 
for the brightest stars in arranging our successive sets. The light of 
the first set would be reduced. Several stars of the first magnitude 
would be excluded from it, and their places taken by stars of much 
inferior brightness, such as 6 and 61 Cygni. In fact the leading 
20 would probably include four or five stars of a magnitude not 
superior to the sixth. Probably the light of the second set would 
also be reduced, but not to the same extent. Several stars of the 
second and third magnitude would, no doubt, be excluded from it, 
and their places taken by fainter stars. But as a set-off we should 
find included in it several first-magnitude stars among them, per- 
haps such giants as Canopus, Wega, and Arcturus. ‘he relative 
preponderance of the second set over the first would thus be in- 
creased. Somewhat similar observations will apply to the subse- 
quent sets. Hach would contain many stars of inferior magnitudes 
to those assumed in my Table, but they would also contain many 
stars of superior magnitudes; and probably by the time that we 
reached the tenth or twelfth set, the brighter and fainter stars thus 
introduced would balance each other, and the average brightness 
would be sensibly the same asin the Table. If further researches 
should show that the steady decline in the total light of each set 
continues below the point where this equivalence may be supposed 


476 Scientific Proceedings, Royal Dublin Society. 


to exist, the evidence in favour of an absorptive medium will be 
proportionally strengthened. 

In conclusion, I am well aware that the data on which I have 
proceeded are not sufficiently reliable to warrant very positive 
conclusions on the subject, though I think the Table which I have 
constructed exhibits in at least two respects—the great rise after 
the first set, and the subsequent steady decline—features which can 
hardly be ascribed to insufficient or erroneous observations. I am 
likewise aware that I have only attacked one branch of the question 
of star-distribution—the distances of the star-masses as_distinct 
from their directions. But notwithstanding this, I believe that 
the views which I have put forward are in some respects new, and 
that they possess a basis of truth; which will, I trust, be a suf- 
ficient apology for laying them before a meeting like the present. 


ean 3 


LXIV.—NOTE ON THE SPECIFIC HEAT OF THE ETHER. 
By GEORGE FRANCIS FITZGERALD, M.A., F.R.S., 
F.T.C.D. ; Hrasmus Smith’s Professor of Natural and 
Experimental Philosophy in the University of Dublin. 


[Read, May 18, 1885.] 


Ir is not quite accurate to describe the quality of the ether that is 
here called its specific heat by that name. The energy of the ether 
per unit volume is not in exactly the same form as heat-energy in 
matter. It is in the form of vibrations transmitted continually 
through it, and is more nearly analogous to sound vibrations in 
matter. As this energy of the ether is, however, intimately con- 
nected with the temperature of the matter that is in it; and as 
its amount depends on that temperature, it is quite intelligible to 
speak of the temperature of a volume of ether, meaning that it 
is on all sides in temperature equilibrium with surrounding matter: 
on these accounts it is intelligible, and, with proper restrictions as 
to its meaning, quite right to speak of the specific heat of the ether. 
There is no danger of the words being mistaken as referring to 
anything else than what they are intended to describe. It must, 
however, be clearly kept in view that the energy per unit volume 
of the ether is not exactly like that of matter. We can also only 
calculate the energy per unit volume, for we don’t know whether 
any perfectly intelligible meaning can be attached to the mass of 
the ether. 

The problem to be solved in determining the specific heat of 
the ether is, What is the increase in the quantity of energy per 
unit volume of the ether that corresponds to its temperature being 
raised one degree? If we consider the temperature equilibrium 
of a surface of lampblack, which is assumed to be approximately a 
perfect absorber and radiator when it is one degree hotter than its 
surroundings, it is seen that it is radiating energy outwards at a 
certain rate, and receiving it at a certain less rate. Now, the 
energy per cubic centimeter of the ether considered as transmitting 
radiations outwards is greater than its energy considered as trans- 
mitting radiations inwards, and it is this difference that causes the 


478 Scientific Proceedings, Royal Dublin Society. 


transference of energy at a certain rate away from the lampblack. 
If we could calculate the whole energy of either of these radiations, 
it would tell us the whole energy per cubic centimeter of the ether 
considered as a medium transmitting radiations in a particular di- 
rection, and six times this amount would evidently be the total 
heat per cubic centimeter of the ether at this temperature. This 
very calculation has been performed approximately for the solar 
radiations, where we can approximately measure the total radiation 
in a particular direction ; but as we only know very roughly, in- 
deed, what is the temperature of the surface of the sun, we can 
only calculate very roughly what is the total heat of the ether per 
cubic centimeter at that temperature. As in addition we don’t 
know the laws of cooling for any sufficiently large range to apply 
it safely to the sun, we could only very roughly, indeed, calculate 
the total heat of the ether per cubic centimeter at temperatures 
with which we are in the habit of dealing. We can, however, from 
experiments on the rate of cooling of lampblack, calculate pretty 
accurately the difference between the energy per cubic centimeter 
of the ether at slightly different temperatures, and this tells us the 


! : i 
specific heat of the ether at this temperature. If 5 be the quantity 


of heat per second lost by each square centimeter of surface of 
lampblack when its temperature is 1° C. hotter than its surroundings 
at the temperature of 0° C., then this energy is distributed over V 
cubic centimeters of ether where V is the velocity of light in 
centimeters, and consequently “ = a is the equation by which 
to calculate c, the specific heat of the ether. The 6 comes in owing 
to this being the energy required to raise the temperature of the © 
ether by radiations going in only one direction. rom several 
sources which, however, only approximately agree with one another, 


I gather that 2 = 0026. The great difficulty in determining this 


is to distinguish between the heat carried off by the gas present, 
and that lost by radiation alone. As V = 3 x 10", we see that 
e=0'2x 10. Of course, as was to be anticipated, this is a very 
small quantity, and is very small even compared with the specific 
heat per cubic centimeter of the gas in a good vacuum. The specific 
heat per cubic centimeter of an air vacuum of one millionth of an 


FirzceraLp —WNote on the Specific Heat of the Ether. 479 


atmosphere, such as we can probably attain, is about 7 x 10°", so 
that the energy required to heat up such a vacuum would be prac- 
tically all used in heating the matter present, only the one thousandth 
part being required to increase the vibrations of the ether present. 

If we apply Dulong and Petit’s law to calculate the specific 
heat of the ether at different temperatures, we obtain the following 
results :— We have obtained the equation that 


dq _ eV 
aa 


= 
expresses the relation connecting | —,, the rate of cooling with c, the 


specific heat of the ether. 
Now, according to Dulong and Petit’s law, 
gq=k (a - a), 

where q is the quantity of heat per second lost by radiation, when 
one body is at ¢ and its surroundings at 4. He also calculated 
that for all bodies a = 1:0077. As I am assuming the theory of 
exchanges, I may as well at once assume that the total quantity 
of heat lost per second is 

Q a ha’, 

Q. = ka” 
radiated in the opposite direction, so that what I have called the 
total heat of the ether is 


and that there is 


_ Cha’ 
= 
To calculate c we can use the result I have just used, and say 
dq a ; ; 
AGH a ka’ . log.a, 
and we thus get 
ip = BS e 


so that, approximately, Q = °35 x (1:0077)’. From this we can 
calculate the total heat per cubic centimeter of the ether at different 
temperatures, and get 

Jib NO se (LOOr a 
and the specific heat per cubic centimeter 

C= 2) ME x DONT 


SCIEN; PROC. R.D.S.—VOL. Iv. PT, IX. 2a 


480 Scientific Proceedings, Royal Dublin Society. 


Hven at the estimated temperature of the sun at 8000° C. this would 
be still only 
e=5:2x 10°; 

but it is evident that if the specific heat of the matter in a gas is 
at all nearly constant up to these temperatures, a very large part 
of the heat energy would be in the ether if the gas were rare. 
This is what one would expect in considering temperatures of spark 
discharges, and accounts for their very short duration. 

It is quite easy to apply the same considerations to calculate 
these quantities upon other laws of cooling, but this whole subject 
is so uncertain it is hardly worth doing more than point out 
what is to be done. 


481 5) 


LXV.—ON SOME METHODS OF MEASURING THE DENSITIES 
OF GASES. By GEORGE FRANCIS FITZGERALD, 
M.A., F.R.S., &e. 


[Read, June 15, 1885.] 


Tur following methods depend on determining the amount by 
which a body is buoyed up when immersed in the gas. 

The first arrangement consists of a large thin glass ball sealed 
up and suspended by a bifilar suspension. The period of oscillation 
of such a ball round a vertical axis depends on the distance apart 
of the suspending fibres, on its moment of inertia, and on the 
weight of the ball. This latter depends on the density of the gas 
in which it is immersed, and by observing the time of oscillation 
of the ball it is possible to determine the density of the gas. In 
order to do this conveniently it is well to make observations of the 
period of oscillation in two gases of known densities, as for in- 
stance in air at the ordinary atmospheric pressure, and at a very 
much lower pressure obtained by exhausting by an air pump the 
vessel in which the ball is suspended. As the relation connecting 
the number of oscillations per second (IV) of the ball with the 
density (8) of the gas in which it is immersed is of the form 

N*= A+ Bo, 
two observations serve to determine A and B, and then any other 
density can be determined in terms of WV, the number of oscilla- 
tions performed by the ball. From experiments I made I believe 
it is easy to arrange that the ball shall perform one hundred oscilla- 
tions without their amplitude being either initially too large or 
finally too small; and if by making the length of the suspending 
threads long (this is better than making their distance apart small, 
as this latter introduces a correction depending on their torsion), 
the period of oscillation be considerable, it is evidently possible to 
determine this period very accurately. It is better to determine 
the period of this oscillation round a vertical axis than its period of 
oscillation as a pendulum, because, without a very long suspension, 


this latter would be more rapid, and would besides be more damped 
Ue D) 


482 Scientific Proceedings, Royal Dublin Society. 


by the gas present. If, however, means were employed for keeping 
up the oscillations, as, for instance, by attaching a small piece of 
iron to the ball, and attracting it when in the middle of its swing 
by means of a magnet, or by moving the point of suspension, or by 
other means, the period of oscillation could be determined to any 
desired degree of accuracy. ‘The complete theory of the experi- 
ment is, however, very complicated. The highest mathematics 
have been expended on calculating the effect of the gas present on 
the period of oscillation of a pendulum; and although the theory 
of a sphere performing oscillations round one of its diameters is 
enormously simpler, yet the way in which its period of oscillations 
depends on the viscosity of the gas is rather complicated, and this 
would make it a rather complicated operation to calculate accurately 
the density of the gas from observations with this instrument. It 
might, however, be used for rough observations, and as the same 
series of observations by giving the logarithmic decrement of the 
amplitudes of oscillations would give a measure of the viscosity of 
the gas, it would be an interesting instrument to make observa- 
tions with on a considerable series of gases and vapours. 

The second instrument I constructed works upon the same 
principle as an old philosophical instrument called a “‘ Baroscope”’. 
It was constructed for the purpose of demonstrating the amount by 
which bodies are buoyed up by the air in which they are immersed. 
A piece of cork or a glass bulb is balanced in a rough balance by 
a lead weight. Ifthis be placed under the receiver of an air-pump, 
the lead weight no longer balanced the cork or bulb, as it is no 
longer assisted by the presence of dense air. A delicate apparatus 
of this kind is evidently capable of exactly the same accuracy as 
the ordinary method of weighing the gas in the bulb, as in Dumas’ 
method, for it is only weighing the gas displaced by the bulb in- 
stead of that in it. As, however, most delicate balances are large, 
I thought it might be well to construct an apparatus of this kind 
on a very small scale, so as to be able to deal with comparatively 
small volumes of a gas. I have, therefore, constructed one as 
follows :—I blew a thin glass bulb of about 1 cm. diameter on a 
fine quill tube which I drew out to a thinner stem about 2 em. 
long. To the end of this I attached a mirror such as is used for 
galvanometers with its plane at right angles to the stem. Ata 
point in the stem close to the bulb I attached two very small and 


FirzgeraLp—Wethods of Measuring Densities of Gases. 483 


sharp splinters of glass which projected away from the stem in 
such a way that the whole thing could be supported on the two 
sharp points of the glass splinters. By bending the stem judi- 
ciously, and attaching small pieces of glass to regulate the balance, 
it is comparatively easy to arrange that the whole thing shall 
balance on these two sharp points, and perform slow oscillations, 
proving that its centre of gravity is close below the line joining 
these points. The mirror should be vertical, and the stem nearly 
horizontal. If it be now supported by the two points resting in 
the concave side of a splinter of a fine glass tube, the whole 
apparatus can bear to be moved about freely without shaking off 
its supports. Ifit be now placed so as to reflect a spot of light 
from the mirror to a vertical scale, or if an image of a vertical scale 
in its mirror be viewed through a telescope, it is possible to observe 
the position of the instrument very accurately. If the density of 
the air in which the apparatus is immersed be changed its position 
of equilibrium alters, and the spot of light is reflected to a different 
point of the scale. I have constructed an instrument of this kind, 
in which the alterations of position on a scale about one meter off 
are as great as the alterations of the mercury barometer gauge of 
the air-pump, showing that it is possible to determine pressures 
with this instrument’ nearly as accurately as with a mercury 
barometer gauge. ‘This is of course the same as determining the 
density of the air, for itis the density and not the pressure of the 
gas present that affects the position of the instrument. I have 
found that the most satisfactory way of using the instrument is to 
have some means, as by an attached sprengle or other air-pump by 
which to alter the pressure of the gas in which the instrument is 
immersed, until the spot of light or image of the scale is in some 
standard position, such as it takes up in air at a known temperature 
and pressure. Under these circumstances the density of the gas 
is the same as that of this air, and an observation of the tempera- 
ture and pressure of the gas enables its density at any other 
temperature and pressure to be calculated. As the whole thing 
can be put inside a tube four centimeters long, and three in 
diameter, it could evidently be easily jackitted so as to keep it at 
a high temperature, and then be used to measure the densities of 
vapours, the only precaution required being that the temperature 
should be sufficiently high to prevent the gas from condensing as 


484 Scientific Proceedings, Royal Dublin Society. 


a liquid on the apparatus. A small correction might also be re- 
quired for the expansion of the glass by heat. As the whole thing 
can be made of glass, for even the mirror need not be silvered, 
it is applicable to such corrosive gases as chlorine, bromine, and 
iodine. 

It is evident that a large number of applications of the same 
general principle are possible: as, for instance, by weighing a 
bulb immersed in a vapour, asin Mr. Joly’s calorimeter, in an ordi- 
nary balance, or by using spring balances to determine the weight 
of the bulb. A very pretty one might be made by an application of 
Messrs. Ayrton and Perry’s shaving springs, and it might be made 
very delicate by reading the position of the bulb by reflection from 
a mirror attached to it. By suspending a thin balloon of collodion, 
distended by a heavy gas in a gas, the density of the latter might 
be measured with a very delicate balance that would not bear the 
weight of a glass: bulb. 


[ 25) 


LXVI.—ON THE COLOURING MATTERS EMPLOYED IN THE 
ILLUMINATIONS OF THE “BOOK OF KELLS.” By 
W. N. HARTLEY, F.R.S., Royal College of Science, 
Dublin. 
[Read, June 15, 1885.] 


No one who has visited the Library of Trinity College, and had the 
privilege of examining the ‘ Book of Kells” can fail to have been im- 
pressed with the beauty, quaintness, and intricacy of the designs, 
and the brillianey of the colours of the illuminated letters and 
embellishments. Owing to the unsatisfactory character of some 
of our modern water-colours and oil paints, I have been asked to 
give an opinion upon the nature of the colours which have re- 
mained permanent after a period of possibly 1200 years. For 
obvious reasons the pigments in question could not be submitted 
to any process of chemical manipulation; hence conjecture, judg- 
ment, and comparison were exercised in deciding upon an answer. 
As any information concerning this interesting and beautiful relic 
of ancient Irish art may possibly be acceptable to the Royal Dublin 
Society, I beg that this may be accepted as an apology for present- 
ing so unimportant a scientific contribution. It is my desire to 
state at the outset that this question was put to me by Mrs. D’Olier, 
whose very beautiful reproductions of the designs in the “ Book of 
Kells” have been executed with such loving care as to excite the 
admiration of all who carefully examine them. Mrs. D’Olier has 
rendered me a very remarkable amount of assistance in some cases 
by giving me a true description of the pigments, and to her my 
best thanks are due. Accepting the earliest supposed date of the 
manuscript as being of the seventh century, it is necessary to restrict 
our ideas of the colours that could be used to those known at, or 
prior to, this time. A very careful examination of the work shows 
that the pigments mixed with gum, glue, or gelatine are laid on 
somewhat thickly—there is no staining of the vellum and no 
mingling of tints. ‘There is, however, as was pointed out to me 
a painting of blue over a ground of green. The colours, which 
are not very numerous, consist of a black, a tint resembling burnt 


486 Scientific Proceedings, Royal Dublin Society. 


sienna, a bright red, a yellow (largely used), a neutral green, an 
emerald green, two blues, a lilac, and a reddish purple. The 
yellow is much employed in filling up finely-traced designs. The 
black of course is lampblack, or possibly fish-bone black, that is 
to say, charred fish-bones, or some other form of carbon artificially 
prepared, in a finely-divided state. The reds, the yellow, the 
greens, and the blues could be obtained either—first, by grinding 
natural mineral substances; second, by grinding artificially coloured 
enamels or glasses. The very appearance of the.colours is in 
favour of the first rather than the second, and altogether against a 
third, possible process of preparation, namely, by the formation of — 
those substances known as lakes which are precipitates of vegetable 
or animal pigments in combination with alumina or lime. By 
making comparisons with ground minerals, I conclude that the 
bright red is realgar (arsenic disulphide, As, S,); the yellow is 
orpiment, auripigmentum, the gold colour of the ancients (arsenic 
tersulphide, As, 8;); and the emerald green is malachite, an ore of 
copper (basic carbonate of copper, Cu,Co,;CuH,O,). The deep 
blue might be lapis-lazuli, the natural ultramarine, but I am in- 
clined to think not, for the following reason: where the green is 
enhanced in beauty by an overlying coat of blue, the effect is that 
of a transparent pigment, such as could not be produced by lapis- 
lazuli. The reddish purple, I am of opinion, is either a finely 
ground glass coloured with gold, or a preparation similar to that 
known as the purple of Cassius. Its very sparing use must not 
be overlooked, and may be justly regarded as an evidence of its 
costly nature. It is not alone that it is employed in a few places, 
but it is put upon the vellum in very thin washes. 

I have sought for information concerning the colours used by 
the ancients, for the reds and yellows recalled to mind the colours 
of Egyptian and Assyrian decorative paintings. There are three 
or four works which deal with this subject: Sir Humphrey Davy’s 
Paper in the Philosophical Transactions of the Royal Society for 
1814, on colours employed by the painters who executed the frescoes 
on the walls of the Baths of Titus and the houses of Pompeii ; 
Dr. Thomas Thomson’s History of Chemistry, vol. i., p. 77, pub- 
lished in 1830; and a recently published Paper by M. Berthelot, 
“Sur les Notations Alchimiques,” in the Annales de Chimie et de 
Physique, 6th series, vol. iv., p. 870; also a work by the same author, 


Hartitey—On the Illuminations of the Book of Kells. 487 


of great value and remarkable interest which has just been published, 
Les Origines de ? Alchimie. The information given by Dr. Thomas 
Thomson is derived from the writings of Pliny, Vitruvius, and 
Dioscorides, he likewise quotes from Sir Humphrey Davy’s Paper. 
M. Berthelot quotes largely from manuscripts and papyri preserved. 
in the National Library at Paris, the Greek manuscript in the 
Library at St. Mark’s, Venice, and the papyrus in the Museum at 
Leyden. According to Thomson, Pliny describes two kinds of 
colours, namely, the florid and the austere. The names of the 
florid colours were, minium, armenium, cinnabaris, chrysocolla, 
purpurissimum, and indicum purpurissimum. ‘The austere colours 
were of two kinds, the native and the artificial. The native were 
known as sinopis, rubrica, pareetonium, melinum, eretria, auripig- 
mentum. The artificial were, ochra, cerussa usta, sandaracha, 
sandyx, syricum, and atramentum. The Greek manuscript from 
the Library of St. Mark is the earliest work on alchemy extant ; 
it dates from the tenth or eleventh century, but the information it 
contains is derived from much earlier Egyptian sources. In de- 
scribing the colours mentioned above, it will be convenient to 
‘quote occasionally from Thomson’s work, and to give the original 
Greek names which appear in the fac-simile representations of 
pages of the manuscripts quoted in M. Berthelot’s work. 

Placing the NaruraL Coxours first, we have the follow- 
ing :— 

feds. 


Cinnabar. KivvaBapic (St. Mark MS.), KwvaBapa (Leyden 
MS.), mercury sulphide, the most abundant ore of mercury. It 
was called minium; and red lead, an artificial colour, was also 
known by the same name. The modern pigment vermillion should 
correspond to this. 

Armenium, a yellow ochre or orange colour. Sinopis. Swwzicn, 
also Siwwaig wov7icn (St. Mark MS.), a red substance now known 
as Venetian red, or raddle. It is used for sheep-marking, and in 
parts of England for reddening the brick floors of cottages. It 
was procured from Pontus in the Balearic Isles, and it was doubt- 
less an iron ore with more or less combined water. 

Ochre. Qypa (St. Mark MS.). “Ochre is merely sinopis 
heated in a covered vessel.” ‘‘ Rubrica, from the name, was pro- 


488 Scientific Proceedings, Royal Dublin Society. 


bably a red ochre.” Substances now known as ochres consist of 
highly ferruginous clays. 

Sandaracha. Savéapacn or Savdapaxy (St. Mark MS.). This 
was realgar, the red arsenic disulphide, As, 8,. Both this sub- 
stance and ochre were found in the island of Topazos in the Red 


Sea. 
Vellows. 


All pigments of this colour examined by Davy proved to be 
iron ochres, sometimes mixed with a little red lead. ‘‘ Orpiment 
was undoubtedly employed, as is obvious from what Pliny said on 
the subject.’’ Davy found in one instance massicot, or lead pro- 
toxide, mixed with some red lead. 

Misy. Muov (St. Mark MS.) was a yellow copperas. 


Greens. 


Chrysocolla. XpucoxodX\a (Leyden MS.). This was a green- 
coloured paint, and, from Pliny’s description of it, could have been 
nothing else but the basic carbonate of copper, now known as 
malachite. All green paints examined by Davy were carbonates 
of copper. The mineral chrysocolla is a blue silicate of copper, 
CuSi0,°2H,0. 


ARTIFICIAL CoLouRs. 
Reds. 


Cerussa usta and minium both signify red lead; this is an 
artificial colour made by roasting lead. 

“‘Sandyx was made by torrefying equal parts of true sandar- 
acha and sinopis,” that is to say, by heating a mixture of realgar 
and ochre. 

Siricum. Supucov (St. Mark MS.). This was made by mixing 
sinopis with sandyx. 

Blues. 


The blue pigment kvavoy (St. Mark MS.) is made by preparing 
a frit or glass made from wood ashes, or alkali, sand, and copper ore. 
It is very largely employed in the different apartments of the Baths 
of Titus. Different shades of colour were obtained by an admixture 
of body colour, most usually chalk. This pigment is quite un- 
altered by exposure to the air and sun. 


Harriey— On the Illuminations of the Book of Kells. 489 


Indicum purpurissimum—“ From the statement of Pliny that, 
when thrown upon hot coals, it gives out a beautiful purple flame, 
this was obviously indigo.” 


Purples. 


Purpurissimum was a high-priced pigment, made by putting a 
kind of white clay into caldrons containing the ingredients for 
dying purple: it was therefore a lake. The celebrated purple dye 
uf the Tyrians was obtained from a shell-fish, the murex or bucci- 
num. Davy ascertained that the colouring matter of the ancient 
. purple examined by him was combustible; the probability is very 
great that it was a preparation of this character. Berthelot says, 
however, that the ancients were undoubtedly aware that glass 
could be coloured purple by means of gold, and that they appear 
to have been not unacquainted with the purple of Cassius, which 
is obtained from a solution of gold by the action of a solution 
of tin. According to our knowledge of this substance, it appears 
to have been discovered by Cassius of Leyden in the year 1683, 
for the earliest description of its preparation we owe to him. In 
Les Origines de ? Alchimie, p. 93, it is remarked that there appears 
to have been an intimate connexion between the preparation of me- 
tallic compounds and the process of dying purple. This is sugges- 
tive of the probability that gold was used for the purpose. 

From the work attributed to Democritus, itis evident that several 
purple colours were in use, namely, cochineal ; archil, obtained from 
lichens; garancine, from the madder root; and likewise indigo. 
The lilac tint in the “ Book of Kells” was probably a lake prepared 
from lichens. See Les Origines de ? Alchimie, pp. 350-861. 

As to the source of supply of these colours, one cannot other- 
wise suppose than that, in the early days of the Christian era, and 
still further back, the art of preparing colours was inseparable from 
the art of painting, for even at the present day there are English 
painters who can prepare their own colours, vehicles and varnishes, 
and whose processes have been handed down to them by their masters. 
The master who taught the art of designing and painting to the artist 
who executed the “ Book of Kells” unquestionably knew how to pre- 
pare the colours. As for the materials, malachite, CuCO,CuH,0,, 
. green in colour, is found near Cork and Limerick; chrysocolla, 
CuSi0,°2H,0, green to blue in colour, is found in the county Cork; 


490 Scientific Proceedings, Royal Dublin Society. 


chrome, heematite, and ochres occur in the county Wicklow ; of red 
hematite of an earthy nature, such as is termed raddle, there is a 
plentiful supply in the county Antrim. Orpiment and realgar must 
have been obtained from elsewhere, and the purples were undoubt- 
edly of artificial origin; it is probable they were brought from 
abroad, and, such colours were no doubt treasured as jewels. 


pce 


LXVII—ON AN ABNORMAL SOLAR SPOT. By WENT- 
WORTH ERCK, LL.D. 


[Read, June 15, 1885.] 


For the last three weeks the disturbance of the photosphere has 
been confined to the southern hemisphere, chiefly between the 
parallels of 12° and 15°. It has manifested itself in the production 
of large, isolated spots, and not, as frequently, in numerous small 
ones. | 

The northern hemisphere has been perfectly free from distur- 
bance. 

On the 9th June a very great spot was observed in lat. 15° S., 
and 385° HK. of central meridian. The umbra, or nucleus, of this 
spot was very much elongated in the direction parallel to the 
solar equator. 

June 10, 675.—The disturbance on this parallel was evidently 
increasing; the single elongated umbra had then resolved itself 
into two, entirely distinct, but both enveloped in a common pe- 
numbra. 

This igs not an unusual occurrence; but the mode in which it 
took place was most remarkable. Hach of the component umbre 
was roughly pear-shaped, the small ends pointing toward each 
other. ‘The penumbra was continuous round the two umbre, but 
much constricted at the place of their separation. 

The general appearance strongly suggested an oblong mass of 
viscous material, stretched till torn asunder by external forces 
applied at each end, the penumbra maintaining a constant 
breadth from the edge of the umbra outwards, and therefore 
being constricted where the breadth of the umbra vanished. 

The appearance presented was utterly inconsistent with the 
idea of an internal disruptive or explosive force, and seemed 
absolutely to require the operation of pulling forces applied at 
each end; or of two powerful currents converging from the fol- 
lowing side on the centre of the original spot. Next day the 
penumbra also had divided itself at the point of constriction, and 
there appeared two ordinary spots, completely separated from each 
other by a central interval of seven helio centric degrees, or about 
39,000 miles. 


492 Scientific Proceedings, Royal Dublin Society, 


The existence of powerful southerly currents was inferred from 
the manner in which the umbree of both—but specially of the preced- 
ing spot—was invaded by bridges of photosphere, entering from the 
southern side, and which promised rapidly to disintegrate the 
entire spot. It is important to ascertain whether either of these 
spots occupied the position of the original. The longitude of the 
original was fortunately observed on the 9th, previous to the dis- 
ruption. | 

Again, on the 11th, after disruption, the longitude of the largest 
of the two separated spots was taken; again on the 13th, and again 
on the 15th. The daily amount of rotation during the first inter- 
val, between the 9th and 11th, was 12°°5; that during the 
second interval, between the 11th and 13th, 12°:80; that during 
the third interval, between the 13th and 15th, 12°°81; while the 
average movement due to latitude 15°, according to Carrington, 
is 13°]. 

The differences, between the quantities are less than the 
possible errors of observation, and therefore we seem justified in 
assuming that the position of the spot observed was the same .as 
that of the original spot, and that the separation of the spots was 
wholly due to the motion of the smaller, or the preceding, of the 
two. 

Tt is to be remarked that the difference of longitude of the two 
spots had increased from 7° on the 11th, to 12° on the 15th; and | 
as the primary spot appears to have retained its original longitude 
unaltered, the secondary spot must have been endued with a proper - 
motion in longitude of its own, the motion being in that direc- 
tion which would shorten the rotation period, and so approximate 
to the rotation period of the equator. 

“I would ask have we here any analogy to the state of affairs 
disclosed by the Jovian atmosphere, in which the red and the 
white spots, having nearly the same latitude, give different periods 
of rotation, and are therefore endowed with a proper motion of 
their own, as though different spherical envelopes of the atmosphere 
were rotating in different periods? 

Position of original spot, lat. 15 S., and it crossed the central 
meridian, June 12, 7°75, G. M. T. 


oe gy 


LXVITI.— FURTHER REMARKS ON STAR-DISTRIBUTION. 
By W. H. 8S. MONCK. 


[Read, June 15, 1885.] 


In a Paper, read before this Society (antea, p. 470), I assumed 
that, although the brightness of an individual star is no test of its 
distance from us, the average distance of the stars of any given 
magnitude is less than that of the stars of the next succeeding 
magnitude. As this assumption did not appear to meet with uni- 
versal acceptance, I desire, on the present occasion, to state some 
reasons in its favour. I need hardly say that the very faintest of 
fixed stars would appear brighter than Sirius, if it approached us 
sufficiently, while Sirius itself might be removed to such a distance 
as to become invisible to our most powerful telescopes. Reasons 
more definite than this will, however, be expected from me, and 
these I proceed to give. 

Assuming that there is no medium in space which absorbs light, 
the general expression for the brightness of a star will be ~ ; 
where / represents the illuminating power of each unit of surface, 
and s the area of the illuminated surface. If there is an absorbing 
medium, the expression will, of course, be somewhat different ; but 
into this I shall not at present enter. Now, if we compare a con- 
siderable number of instances taken at random, in which the value 
of = is high, with a considerable number, likewise taken at ran- 
dom, in which the same value is much lower, is it reasonable to 
suppose that the difference depends wholly on the factors / and s, 
and that the average value of d is either unaltered or increases 
when the average value of the fraction diminishes? I think not. 
But we are able to take another step. ‘There is probably no 
instance in which we are able to ascertain the value of.s or the ex- 
tent of illuminated surface which the star turns towards us; but 
we can form a very fair estimate of the value of /, and are thus 
enabled to conclude positively that several of the stars of the first 


494 Scientific Proceedings, Royal Dublin Society. 


magnitude do not owe their position in the stellar scale to the in- 
tense illumination of the unit of surface. When a cold body is 
gradually heated it gives forth at first dark heat, and then a red 
light, after which the other hues in the solar spectrum gradually 
spring up, and finally the ultra-violet chemical rays make their 
appearance. At every stage in this heating process the illumina- 
ting power of the unit of surface increases; and the illuminating 
power of the unit of surface can thus be determined within certain 
limits by the nature of the stellar spectrum, being lowest in the 
ease of the red stars, and highest in that of the brilliant white or 
blueish stars—at least, unless the latter owe their peculiar hue to _ 
the loss of the red rays, which fact would always be revealed by 
the spectrum. We are in this manner able to conclude that the 
degree of illumination of several stars of the first magnitude is not 
above, but below, the average. Such stars, for instance, are - 
Aldebaran, Antares and Arcturus. If these are really distant 
stars, the extent of illuminated surface must be enormous. From 
their lower temperature these stars are probably in a more con- 
densed condition than the brilliant white or blueish stars already 
alluded to, and the masses which we would have to assign to them, 
if they were very remote stars, would be almost incredible. Before 
leaving this subject, | may remark that our early astronomers, at 
least in the northern hemisphere, appear to me to have framed 
their nomenclature with a view to the colour of the stars. If we 
examine the stars of the first magnitude visible in this country in 
alphabetical order, we shall find ourselves passing at almost every 
stage from a redder to a whiter or bluer star—the few departures 
from which rule may perhaps be explained by a change of colour 
since the names were imposed. ‘Thus, Capella, which stands pretty 
high in the alphabetical list, is described by many of the earlier 
writers as a red or reddish star. 

However, it is said that, though much labour has been expended 
in trying to ascertain the parallaxes of stars of the first magnitude, 
very few of them present a sensible parallax, while several of the 
fainter stars do so, and also that many faint stars exhibit a larger 
proper motion than the stars of the first magnitude. ‘This reason- 
ing would be conclusive against a theory which supposed that the 
distance of a star was invariably indicated by its magnitude; but 
T think it has little force against one which only supposes that the 


Moncocx— On Star-Distribution. 495 


average distance of the stars of any given magnitude is greater than 
the average distance of the stars of the magnitude next above it. 
Nearness and remoteness in the case of the fixed stars must be deter- 
mined on a different scale from that which we employ in dealing with 
the solar system. ‘The nearest of them is much more remote than 
Neptune; but it is not improbable that there are stars within the 
range of our telescopes whose distance exceeds that of a Centauri 
more than a thousandfold. Any star whose distance does not ex- 
ceed ten times that of a Centauri must be regarded as a near star. 
On the hypothesis of uniformity there would be one thousand such 
stars, and the actual number is as likely to exceed one thousand 
sa to fall short of it. But, taking the annual parallax of a 
Centauri at =% of a second, the annual parallax of a star ten times 
as distant would be only 52,5 of a second; and I think it will be 
admitted that such a parallax could not be measured by our pre- 
sent methods and with our present instruments with any approach 
to accuracy. ‘That we have.tried to find a parallax for any given 
star and have failed is therefore no proof that it is not a near star. 
In fact, the number of stars which are universally admitted to have 
a sensible parallax might almost be counted on one’s fingers. But, 
to revert to the parallax of stars of the first magnitude, I turn 
again to Dr. Ball’s Elements of Astronomy, which contains a valu- 
able collection of facts which are quite sufficient for my present 
purpose. Beside a Centauri I find a very fair concurrence by 
different observers in the case of Sirius, the parallax of which can ~ 
hardly be less than + of a second. ‘Two measures only are given 
of the parallax of Arcturus, but they agree in fixing it at between 
1 and £ of a second. The more recent determinations of the paral- 
lax of Wega are also in fair agreement, and give a result larger 
than in the case of Arcturus, and perhaps equal to Sirius. There 
is therefore, I think, good reason to conclude that four stars of the 
first magnitude possess a sensible parallax; and, judging from 
Dr. Ball’s figures, there are at least four more with regard to 
which further investigation may not improbably lead to the same 
conclusion, though the present data are either too insufficient or 
too discordant to afford any positive result. These are (3 Centauri, 
Al Tair, Capella and Procyon. If I am right in these conclusions, 
20 per cent. of the stars of the first magnitude have a sensible 
parallax, and further research may not improbably increase this 


SCIEN. PROC. R.D.S.—VOL. IV. PT. IX. . 2U 


496 Scientific Proceedings, Royal Dublin Society. 


number to 40 per cent. Now, is there the smallest probability that 
a similar per centage of the stars of any other magnitude will be 
found to possess a sensible parallax ? I think not. When fainter 
stars have been examined for parallax they have been almost 
always selected for large proper motion, or some other supposed 
indication of nearness, and were not therefore fair specimens of 
their class. But what do we find even as regards these selected 
stars? Of four hundred and nine, examined by Dr. Ball at Dun- 
sink, two only gave a sensible parallax. Granted that a parallax, 
equal to that of Sirius or Wega, might have escaped observation 
on the methods employed by Dr. Ball, still the fact that only 4 
per cent. of the specially selected stars turned out to have a sensi- 
ble parallax is, I think, rather a startling one. No doubt astrono- 
mers were at first a little surprised at finding that several stars of 
the sixth magnitude have a sensible parallax; but, as the stars of 
that magnitude are one hundred and sixty times as numerous as 
those of the first magnitude, it would require one hundred and 
sixty stars with sensible parallaxes to compensate for a Centauri 
alone. There seems to be no chance of detecting one-fourth of 
that number. The evidence afforded by researches on parallax 
hitherto is therefore, I think, entirely in favour of the smaller 
average distance of the brighter stars. Individual faint stars are 
sometimes nearer than individual bright ones; but this does not 
affect the question when we are dealing with averages. 
From parallax I pass to proper motion. I think there is no 
doubt that the great proper motion of some faint stars is mainly 
due to the fact that the actual velocity of their motions is very 
great. Grounds might, perhaps, be alleged for holding that the 
average velocity of small stars is greater than that of large ones ; 
but, at all events, there is no more reason to believe that all stars are 
moving with the same velocity than that all stars are equally bright 
at the unit of distance. The test of proper motion, however, has 
a defect from which that of brightness is free. Besides the dis- 
tance of the star and the velocity of its motion; the direction of the 
motion must also be taken into consideration, for, if the star is 
moving towards us or away from us, the proper motion will appear 
insignificant, although the distance may not be great, and the 
actual velocity of motion may be considerable. However, the evi- 
dence of proper motion is, I think, likewise favourable to the 


Moncx—On Star- Distribution. 497 


smaller average distance of the brighter stars. In M. Flam- 
marion’s Introduction to his Star Atlas I find a table of sixty stars 
having the greatest proper motion observed up to that period, ar- 
ranged in order of magnitude; and, comparing these with the 
total number of stars of each magnitude as given by Dr. Ball, I 
ascertained what per centage of the stars of each magnitude fell 
into this selected batch of sixty. The result is as follows :— 


Per Cent. Per Cent. 
Ist Magnitude, . 20: 6th Magnitude, . 0°41 
2nd Magnitude, . 1°54 7th Magnitude, . O11 
érd Magnitude, . 1°58 8th Magnitude, . 0:02 
4th Magnitude, . 1:17 9th Magnitude, .. 0:003 
oth Magnitude, . 0°63 All others, . t (0) 


Here, again, no doubt, the proper motions of the stars of the 
first magnitude have been examined more carefully than those of 
the fainter stars; and, in the case of some of the latter, even since 
the publication of M. Flammarion’s Table, large proper motions 
have been discovered. But I think it very unlikely that the stars 
of the first magnitude will be displaced from the position which 
they occupy ; for, the last of the four which are included in M. 
Flammarion’s list—Procyon—is the thirty-eighth in the Table; 
and it will therefore be necessary to discover twenty-two fainter 
stars with larger proper motions to exclude him from the leading 
sixty. But even if we lost both Sirius and Procyon, the two 
stars which there is‘no chance of displacing—a Centauri and Arc- 
turus—would secure the first place for the stars of the first magni- 
tude, which would still contribute ten per cent. of their total 
number to the list in question. | 

I proceed to mention some other indications of comparative 
nearness, which, so far as I am aware, are almost exclusively con- 
fined to the brighter stars—that is, to the stars of, say, the first 
four magnitudes. One of these consists of two well-separated 
stars, one of which nevertheless revolves round the other in a 
moderate period. Such a star, for instance, is § in the Great Bear, 
where the two stars can be easily separated, while the period of 
revolution is only about sixty years. Sirius is in the same position, 
though his companion is so faint that a powerful telescope is neces- 
sary, not to separate the stars, but to detect the smaller one. We 

2U2 


498 Scientific Proceedings, Royal Dublin Society. 


cannot suppose such double stars to be very distant from us with- 
out ascribing an almost incredible velocity to the revolving star. 
It is otherwise, of course, when the double star is a very close one, 
or when the period of revolution is very long. But, I believe that 
duplicity of any kind occurs more frequently in the case of the 
brighter than of the fainter stars, and that the average distance of 
the pairs is also greater in the former case than in the latter. 
This is exactly what we should expect to find if the brighter stars 
were nearer. In speaking of double stars, I exclude cases in which 
the two stars are not known to have any physical connexion, and, 
though nearly in the same direction, may be at very different dis- 
tances from us. Excluding these stars, I believe the feature on 
which I am insisting will be much more frequently found among 
the brighter than the fainter stars, though I am unable to give any 
statistics as to the proportion. 

My next reason is founded on what I may call star-systems— 
stars fairly separated from each other, yet moving in nearly the 
same direction and with nearly the same velocity. Such, for in- 
stance, is the case with five of the seven stars which form the 
Plough, or Charles’s Wain, in the Great Bear. They are all 
bright stars, but probably further examination will show that some 
faint stars in the same direction are also members of the system. 
Now, considering the great angular distances of these stars from 
each other, their mutual action would be almost inconceivable if 
they were not near stars in the sense in which I have been using 
that phrase. I think I may go a step farther. ‘This system ap- 
pears to be sweeping through space uninfluenced by the action of 
the numerous fainter stars which we see around it; for if it once 
got entangled in a mass of stars moving in different directions and 
with different velocities, it is difficult to see how the common mo- 
tion of the system could be preserved. ‘The natural inference 
therefore is, that these faint stars are much more distant from us 
than this system of five—that, great as the mutual distances of the 
members of that system must be on the lowest computation, the 
distance of the system from the general mass of the stars in the 
Great Bear is still greater. A somewhat similar system exists in 
Cassiopeia’s Chair, embracing most of the brighter stars in that 
region. The angular distance of its members is less than in the 
Great Bear, but the component stars are also less brilliant—the 


Moncx— On Star- Distribution. 499 


two indications of greater distance thus concurring. Still, if the 
motions of this system are independent of those of the great 
mass of the stars in Cassiopeia’s Chair, as they appear to be, this 
mass of faint stars must be much more remote than the brighter 
stars which form the system. This result is the more remarkable 
because the fainter stars are unusually dense in this region. 

Further evidence on the same subject is afforded by clusters of 
stars. Of course if any cluster was brought nearer to us the com- 
ponent stars would appear to widen out, and though for some time 
the density of the cluster might be preserved by the springing up 
within it of faint stars, which were invisible at the greater distance, 
if it still continued to approach us, a pretty wide separation of the 
component stars would ultimately be effected. Now itis, I believe, 
a fact that in every cluster where the component stars are tolerably 
bright, as in the case of the Pleiades and the Hyades, a wide sepa- 
ration is effected by the telescope, while in all very dense clusters 
the component stars are extremely faint. Our densest clusters in 
fact are not visible to the naked eye at all, and in inferior tele- 
scopes they appear only as nebule. It seems difficult to explain 
the inverse relation between the density of the clusters and the 
brightness of the component stars on any other hypothesis than 
that the average nearness of any group of stars increases with 
their average brightness. 

I may likewise allude to the general distribution of bright and 
faint stars over the sky. If brightness did not depend on distance, 
we might expect to find the same proportion existing everywhere, 
or at all events to find this proportion as variable in one direction 
as in another—to find, for instance, that if the density of the faint 
stars increased more rapidly than that of the bright stars in one 
rich region, another rich region would be found in which this state 
of things was reversed. ‘This, however, does not appear to be the 
case. When we pass from a poorer to a richer region I believe 
the brighter stars are never found to increase as rapidly as the 
fainter. Their arrangement seems to indicate that they are moving 
at a comparatively short distance from us, while the great mass of 
the faint stars lie far beyond them. There is no instance, I believe, 
in which a really bright star is known to belong to a cluster or to 
a system, the other components of which are much inferior to it in 
brilliancy. Hxcept in the case of the faint companions of a 


500 Scientific Proceedings, Royal Dublin Society. 


bright double or multiple star, the brighter stars seem to keep 
aloof from their inferiors, and when they form systems they keep 
these systems to themselves. 

I may further remark that the principle that faintness is a 
mark of great distance has been acted on by astronomers in their 
researches after parallax, and in several instances it has been 
verified by the results thus obtained. This was the mode in which 
Bessel first determined the parallax of 61 Cygni. Suspecting from 
its large proper motion that this star was near us, he selected two 
fainter stars in the neighbourhood, which he assumed to be so re- 
mote that for practical purposes their distances might be regarded 
as infinite. The same operation was repeated by Struve on another 
faint star in the neighbourhood, and the near coincidence of their 
results seems to prove that the stars thus selected are really much 
more remote than 61 Cygni. Struve’s star was fainter than either 
of Bessel’s, and the slight discrepancy in their results would be 
explained by supposing that it was also more distant. The same 
method has subsequently been adopted by other observers. Had 
the stars which Bessel and Struve selected for reference been much 
brighter than 61 Cygni, their results might not have met with such 
universal acceptance. Possibly, too, these results would have been 
different. 

On these grounds, I am inclined to think that there is a suffi- 
cient average correspondence between the magnitude of a star and 
its distance to justify the conclusions: which I draw from that 
assumption as approximations to the truth. Of course it is only 
when we are dealing with wide averages that such results are of 
any value, and therefore their value increases with each successive 
magnitude, provided that we have sufficient data to work upon. 
When we take in a wide region of space, distributed impartially in 
every longitude and latitude, it seems probable that the peculiari- 
ties of different portions of this region will compensate each other, 
and that the general average, computed on the hypothesis of uni- 
formity, will not be far from the truth. I already noticed that as 
the twenty brightest stars are certainly not the twenty nearest 
stars, the average distance of a first magnitude star is almost 
certainly greater than it would be on the hypothesis of uniformity. 
But this is only partly true of the stars of succeeding magnitudes. 
All subsequent magnitudes will indeed contain stars which owe 


Moncx—On Star- Distribution. 001 


their position, not to their distance, but to their great brilliancy 
at the unit of distance, but they will also contain stars whose dis- 
tance is less than the average, but whose want of absolute brilliancy ' 
has prevented them from figuring in a higher class. How far we 
should have to go before this kind of compensation would become 
perfect it is not easy to determine, but at all events we would ap- 
proach nearer to the theoretic value at every stage—the average 
increase of distance being below the theoretic value during the 
earlier stages of the process. This theoretic value is easily com- 
puted if we assume that no light is absorbed in passing from the 
stars to us. The average light of the stars of any magnitude 
being taken as 2 of that of the stars of the preceding magnitude, 
the average distance will be found by multiplying the average 
distance of the stars of the preceding magnitude by £,/10 or 1:58 
nearly. ‘This value of 2, I may add, is closely approached by the 
. recent computations of M. Littrow and Mr. Pogson, as well as 
being very nearly the mean of Dr. Ball’s authorities. This theo- 
retic value of 1:58, however, is liable to be reduced at the earlier 
stages of the process by the cause which I have mentioned, while 
if there is in a space a widely-diffused medium which absorbs light 
it would also be affected by the absorption, especially at the later 
stages. Tio what extent this would affect the theoretic value 
would depend on the law of absorption. 

It occurred to me since my former Paper that the effects of 
this supposed absorptive medium might be revealed in a somewhat 
different way. On the hypothesis of uniformity the entire number 
of stars up to any given magnitude would be included in a sphere 
having the earth as its centre. The total light of all these stars 
would be proportional to the radius of this sphere, while the total 
number of the stars in question would be proportional of the cube 
of the radius (assuming that no light was lost in the passage). We 
would thus have two modes of calculating the proportion which 
the radius of any of these spheres bore to the radius of any pre- 
ceding sphere, viz. :—Ist., by computing the total light in each 
case (which could be easily done when we know the number of 
stars of each magnitude and their proportionate brilliancy) ; and 
2nd, by finding the total number of stars comprised in each sphere, 
and comparing the values of the cube roots of these numbers. If 
there was no absorption, and the averages derived from the hypo- 


502 Scientific Proceedings, Royal Dublin Society. 


thesis of uniformity were approximately true, we should arrive at 
the same result by both modes of computation ; but if light is ab- 
sorbed by the medium, the value derived from the total light should 
always be less than that derived from the total number of stars. I 
accordingly tried this method on the stars from the first to the 
ninth magnitude inclusive, taking the numbers of the stars from 
Dr. Ball’s Table, and computing the total light on the assump- 
tion that the average light was represented by the multiplier 2 at 
each stage of the descent. The first pair of figures shows a wide 
divergence in the opposite direction from that which would be pro- 
duced by the absorption of light, which I attribute to the great 
richness of the region of the second magnitude stars, our field not 
being yet wide enough to render the uniformity-hypothesis approxi- 
mately true. At the next step the divergence is in the same direc- 
tion, but much reduced; at the third stage the figures are practically 
equal; and in the remaining five the figure derived from the num- 
ber of stars is considerably in excess of that derived from the total 
quantity of light, both figures displaying a good deal of steadiness, 
as appears by the following Table :— 


‘ 


pe alee 
Ist to 2nd, 1°62 2°30 
and to 3rd, 1:48 | 1:66 
3rd to 4th, 1°37 | 1°36 
4th to Sth, 1:37 2 aenry 
5th to 6th, 1-41 1:25 
6th to 7th, 1°53 1:32 
7th to 8th, 1:48 1:30 
8th to 9th, 1:51 1:33 


The divergence in one direction, at the earlier stages, does not 
compensate for the opposite divergence at the later ones. The 
multiplier which represents the total change from the first to the 


Moncx—On Star- Distribution. 508 


ninth sphere, as computed from the number of stars, is 21°54, while 
that computed from the total light is only 18°82. This would 
seem to indicate a loss of at least 123 per cent. of the total light 
of all the stars up to and including those of the ninth magnitude, 
which of course implies a much greater loss in the case of an 
average ninth magnitude star; and if I had made the computation 
between the second and ninth spheres instead of the first and 
ninth, the loss would appear to be over 35 per cent. 

As our knowledge of the ether increases, I think the chances of 
its proving a light-absorbing medium are becoming greater, on 
purely physical grounds, and apart from astronomical data. We 
know of no other medium which transmits vibrations without ab- 
sorbing some of them. The ether is an active agent in the produc- 
tion of electric and magnetic phenomena, and thereby, no doubt, 
assists in the production of light and heat otherwise than by trans- 
mission. Independently too of the supposed evidence of Encke’s 
comet, there are magnetic phenomena in which the ether, when in 
a particular condition, appears to be capable of resisting the motion 
of ponderable matter. ‘There seems, moreover, to be some reason - 
for thinking that all bodies in the universe (except a small number, 
- which are temporarily heated by collision or some similar cause) 
are perpetually cooling ; and if so, what becomes of the heat unless 
it 1s absorbed by the ether? However, I shall not pursue this 
subject farther. 

The absorption or non-absorption of light will of course make 
a considerable difference in our estimates of the distances of very 
faint stars. From the foregoing figures it would seem that the 
average distance of a star in the ninth sphere is about twenty-one 
and a-half times that of a star in the first sphere. The ninth sphere, 
however, includes not merely the stars of the ninth magnitude, but 
those of all magnitudes higher than the ninth, so that the average 
distance of a ninth magnitude star will be greater than this. It 
cannot, however, be very much greater, because 71 per cent. of the 
total number of stars included in the ninth sphere are stars of the 
ninth magnitude. If we assume it to be twenty-six times as great 
as that of a first magnitude star, we shall probably have made a 
sufficient allowance. On the hypothesis of uniformity, however, 
and not allowing for any absorption, the ratio would be (4,/ 10) 
to one, or very nearly thirty-nine times as great. I have already 


504 Scientific Proceedings, Royal Dublin Society. 


given a reason for thinking this figure too high, but the two re- 
sults could evidently be reconciled by a large absorption. On 
that view the loss of light would be so considerable that a star 
should be placed at twenty-six times the distance of a first magni- 
tude star, in order that the light which reached us should be that 
due to thirty-nine times the distance, none being supposed to be 
lost. The absorption would thus amount to % of the total light. 
Probably the absorption is not so large as this, but if we halved 
the difference between the two results the loss would still amount 
to at least 36 per cent. Ii there is an absorption therefore a faint 
star will always be nearer to us than we would infer from the 
intensity of its light, on the hypothesis of uniformity. How much 
nearer will of course depend on the amount of the absorption. 


[ 505 J 


LXIX.—ON THE OCCURRENCE OF BERYL. WITH SCHORL 
IN GLENCULLEN VALLEY. By PROFESSOR J. P. 
O’REILLY. 


[Read, June 15, 1885.] 


Iw the mineral collections existing in Dublin may be found speci- 
mens of beryls, from various places in the neighbourhood of 
Dublin where granite occurs. Samples from Dalkey Quarries, 
from the Three-Rock Mountain, from places in Wicklow, such as 
-Glenmalure and Glenmacanuus, have been mentioned. The speci- 
mens now shown were found in quarries, known locally as the 
Kearneystown Quarries, situated in the Glencullen Valley, near 
Glencullen Bridge, on the south side of the stream. These quarries 
are opened in granite, and have been worked for some time, so 
that the excavations are extensive, and show a considerable front 
of rock. The distance from the stream is about eighty to one 
hundred yards, and in the principal quarry there exists a joint or 
fissure which, so far as I could judge, is parallel to the course of 
the stream, presenting a direction about N. 62° 40’ W. (being the 
same as that of the group of jointings which I described as occur- 
ing frequently in the environs of Dublin with a mean direction of 
N. 60° 41’ W.). This joint is filled in certain parts of the quarry 
with what is called “rotten stuff” by the quarrymen, that is, 
granite much broken and decomposed, and presenting in several 
places along its direction, bunches of schorl, large crystals of 
orthoclase and muscovite mica, these assuming a somewhat plumose 
arrangement. At one particular point a rock was detached, which 
contained not only these minerals but also well-marked crystals 
of beryl. The quarrymen threw it aside, and broke off some of 
the stuff. The large bunch I secured, and it is now in the gallery 
of the Royal College of Science. The small hand samples now ex- 
hibited show the crystals with some well-marked forms of the prism 
and. basal section; at the same time it is clear that the interior 
of the erystals is not homogeneous, and has undergone a certain 
amount of decomposition. It is evident that these crystals were 


506 Scientific Proceedings, Royal Dublin Society. 


formed prior to the schorl, as they are completely enclosed by this 
mineral, the crystals of which are flattened on the faces of the 
beryls. In other places the beryl is completely decomposed, and 
has resulted in a clay of a light-green colour and unctuous feel, which 
may be remarked in many other granites of the county Dublin, 
but which we may thus presume to have resulted from the decom- 
position of beryls. It will be of interest to determine whether 
these clays contain any glucina, or whether, in the process of de- 
composition, all the glucina is carried off in a soluble state. It 
will also be interesting to determine whether the green earths, here 
and there noticeable in the Dalkey granites, are really to be accepted 
as resulting from the decomposition of beryls, or to be considered 
as independent minerals. 

There is a further point in connexion with this occurrence of 
beryl worth noticing. It is the evidence it furnishes as to the 
depth and extent of the main jointing affecting the granite masses 
of the county Dublin, and the probability that it points to some 
of these joints developing into lodes at their contact with the mica 
slates, which in this particular case are not far distant. 

Lastly, I look upon the existence of this well-marked jointing 
as an evidence that Glencullen Valley is a fissure valley, which is 
quite in keeping with its markedly rectalineal direction. 


L ale J 


LXX.—NOTE ON THE OCCURRENCE OF GRANITE POR- 
PHYRY IN THE THREE-ROCK MOUNTAIN, COUNTY 
DUBLIN. By PROFESSOR J. P. O'REILLY. | 


[Read, June 15, 1885. ] 


THE mass of granite which has received the name of the Three-Rock 
Mountain, though apparently of very simple outline, presents in cer- 
tain places channels and gorges which become recognizable from a 
distance towards sunset when the rays of the sun, passing at a very 
low angle, bring out the inequalities of the surface very markedly. 
It may thus be seen that certain shallow gorges and channels occur, 
and that their directions are apparently parallel. One of these is 
known to the quarrymen of the village of Sandyford and environs 
as “ Phuldhu,” and in the southern end of it I found last year a 
block of granite, partly detached from the mountain, the texture 
of which struck me as interesting by reason of the great develop- 
ment of the orthose crystals. I had the blocks separated from the 
main mass, and saw-cut and polished in the part where these 
crystals appear. The slab resulting, now exhibited, presents a 
very agreeable colour, owing to the size and structure of the 
flesh-coloured orthose crystals. I had already noticed the direc- 
tions of these gorges, and included this one in the group of joint- 
ings, having the mean direction N. 6° 57’ W. I, therefore, assume 
that the porphyritic character points to the presence of one of these 
joints in the gorge, along which the same character may be found 
to present itself in other places. Were the rock thus character- 
ized more abundant, it might give rise to an adaptation for orna- 
mental purposes; but I am not aware of it occurring with this 
appearance in any other locality of the mountain. 


008 Scientific Proceedings, Royal Dublin Society. 


LXXI.—NOTE ON AN ABNORMAL DEVELOPMENT OF PICEA 
PINSAPO. By GREENWOOD PIM, M.A. 


j Read, June 15, 1885. | 


Passtne through Powerscourt demesne, a week or two ago, my 
attention was arrested by a curious growth, on a rather large speci- 
men of Picea pinsapo, of which I submit a photograph. A large 
side branch had divided into two, each of which was about 14 inches 
in diameter. Of these one grew in the usual horizontal manner, 
while near its origin the other developed into a gouty swelling, 
from which the normal branch was not much more than half an 
inch thick. At right angles to this, and from the swelling, arose the 
- growth which caught my eye, a dense bush of short rather slender 
shoots, of a pale yellow green, quite different from the usual colour 
of the young growth in this species, and so thick as to be quite 
impenetrable to vision, somewhat reminding one of the “nests” 
of a birch tree. It contrasted in colour much more than appears 
. in the photograph. Further examination showed several other 
instances of a similar growth on this tree, but none so large or 
perfect as this one, which was about 2ft. high by 1 thick. The 
tree is a very fine one, about 30 ft. in height, and the trunk at the 
base about 15 inches in diameter. 


fF 509° 4 


LXXII.—ARTIFICIALLY-PRODUCED GOLD CRYSTALS. BY 
WILLIAM N. ALLEN. 


[Read, December, 15, 1884. ] 


Gop crystals are occasionally found native; the occurrence, how- 
ever, of the crystalline metal in the laboratory has, as far as I can 
find, not yet been published. 

The crystals which are microscopic were donectcd by a neutral 
solution of chloride of gold and sodium, and appear as regular 
three- or six-sided tables perfectly crystalline in structure; the 
forms are those of octahedra, the largest observed being >;%5 inch 
in diameter. 

Many present surface-markings, of which I exhibit a good 
example; there is considerable difficulty in obtaining definition, 
owing to the great surface reflection. 

With a very oblique light, it can be observed that the edges 
present a bevelling, the reflection being such as would be given by 
erystals having the forms figured in Muspratt’s Chemistry, vol. i1., 
ps 200: 

The only note I find which refers to gold separating in lamine 
from solution has been kindly given me by Mr. R. J. Moss, F.c.s. 
It is from a work by M. Golfier Bessayer, Annales de Chimie et de 
Physique, published in 1832, in which it is stated that a solution of 
gold chloride, prepared with as little acid as possible, and which 
was laid aside for some time, then contained a quantity of small and 
very brilliant spangles (paitletes) of gold, the author apparently 
did not recognize them as erystals. 

The word “spangle” is used by Fresenius in his Qualitative 
Analysis, 8th ed., p. 144; but the spangles of gold obtained as 
directed by him do not present crystalline structure. 

In connexion with this subject, I exhibit copper crystals de- 
posited in a mixture of cupric sulphate, treacle and vinegar; the 
forms are similar to those of the gold crystals, and to those of 
copper, which occur in the well-known “ Aventurine glass.” 


TB J 


LXXIII.—_NOTES ON SOME IRISH FISHES. By J. DOUGLAS 
OGILBY, Senior Assistant-Zoologist, Australian Museum, Sydney. 


[ Read, June515, 1885. ] 


Tue recent publication of Dr. Francis Day’s important work on 
the Fishes of Great Britain and Ireland has led me to a close 
examination of the Irish species and localities mentioned, and as 
my notes have extended to a considerable length, I now offer them 
as a contribution towards a revision of the Irish Fishes, upon 
which my friend Mr. A. G. More and myself have been for 
some time engaged. 

Labrax lupus..—In addition to the example mentioned ey. 
p. 10) as having been recorded from Portrush, county of Antrim— 
which, if mine from Zoologist, 1876, p. 4754, should by rights be 
from Portstewart, county of Derry—lI have since obtained a mag- 
nificent specimen, scaling 133lbs., caught in my presence with a 
seine on the west strand, Portrush, Oct. 8,1878. The stomach con- 
tained numbers of Paguri, and two young coal-fish, each about 
five inches in length. Shortly after this date I was informed of 
the capture of another specimen, weighing over 10 lbs., by a boy 
engaged in fishing for flukes with a lug-worm bait, a short distance 
inside the mouth of the Bann. On the 17th July, 1888, I saw a 
bass of about 6lbs. weight, which had been taken in the Foyle, 
opposite St. Johnston, and about thirty miles above the mouth of 
the river. Although the man who had it stated that he had seen 
one previously, it was so little known that he called it a “big 
herring.’ From these observations it would appear that the 
bass only visits our northern coasts in the autumn, as a straggler 
of large size and solitary. In the Belfast market they begin to 
appear about the middle of June, from the nets set in the Lough. 

Polyprion cernium.—The only specimen of which I have heard 
is that recorded by Andrews (Wat. Hist. Rev., vol. i. p. 38), as 
having been caught off Ventry, Dingle Bay, during September, 
1854; weight, 1031bs; length, 254 inches; and is probably the 
same as that mentioned by Dr. Day. 


1 The Latin names are taken from Dr. Day’s Work. 


Ocitsy—On some Irish Fishes. oll 


Mullus barbatus.—Is said to occur, but very rarely, in the Bel- 
fast market. I have failed to obtain an example. 

Pagellus centrodontus.—Abundant at Portrush, where it is called 
“brazier”’. Fished for with hand-lines from a boat anchored at 
the edge of a tide or in eddies, the first two hours of the flood 
being the best time for this fishery, and the baits employed being 
erab, or boiled limpets. Also taken commonly on “ spotty ground’’, 
i.e. patches of rock and shell-sand, upon lines set in a slack tide, 
and baited with mackerel, garfish, or sand-eel, with a mixture of 
whelk. I have known a single example to have taken an india- 
rubber eel while whiffing for pollock. 

Cantharus lineatus.—Rutty was evidently mistaken in his iden- 
tification of this species, which has not been since taken in the 
localities mentioned, though his record would lead one to suppose 
that it was not uncommon. I never saw one either at Kingstown, 
Dalkey, or Killiney, in all which places I have frequently fished. 
In botanical matters also, as well asin his account of the Mammals 
of Dublin, little reliance can be placed on Rutty’s accuracy. 

Sebastes norvegicus.— There seems to be an error in the first 
Irish record given by Dr. Day, p. 44; the notice in the Dublin 
Nat. Hist. Proc. runs. somewhat as follows :—“ Two fine specimens 
taken in the month of March last, on the long lines set for ling in 
deep water off the Wild Bank, Dingle Bay.” The Paper was read 
on May 4, 1849, in above Proc., vol. u. p. 61. 

[ Cottus gobio.—There seems to be no doubt that this species 
does not exist in any of our northern rivers. | 

Cottus scorpius.—Both this, and the next species, C. bubalis, 
are called “Johnnie Doran” (never, that I have heard, “ miller’s 
thumb,” as stated in the foot-notes to pp. 80, 81, of Thompson) 
on the coast about Portrush, and ‘“ cobbler” at Bray, where both 
are common, the latter, however, being the more numerous of the 
two. 

Trigla cuculus.—Next to the grey gurnard, this is the most 
abundant species about Portrush, its proportionate numbers with 
T. hirundo being about three to one (vide Thompson, p. 73, contra). 
It is probable that Thompson was led astray in his computation, 
because of this fish being kept mostly for home use, while its larger 
congener is sent to market. 

Trigla hirundo.—I have on several occasions taken this fish 

SCIEN. PROC. R.D.§8.—VOL, IY. PT. IX. 2X 


912 Scientific Proceedings, Royal Dublin Society. 


whilst whiffing for mackerel, but generally when putting the boat 
about, and in water not exceeding five fathoms ; when thus hooked 
they play fiercely. I have, however, observed individuals not un- 
frequently on the surface above a considerable depth, and once 
unsuccessfully pursued an example, which had captured a fluke 
too large to be swallowed with ease. The largest example which 
I have ever taken measured exactly two feet, and weighed 
d41bs.; this was in July, and the fish in perfect condition. I 
cannot imagine one of 14l1bs.; surely there is some mistake or 
slip of the pen? 

‘Agonus cataphractus.—I have never known of a specimen being 
caught by trawlers or shrimpers on the Derry coast. My only 
example was taken from the stomach of a cod, caught about six 
miles from land, in twenty-five fathoms. 

Lophius piscatorius.—Locally called “ Brahwin,” and not un- 
common. The largest example which I obtained measured 5 feet 
7 inches, and contained a ling of 8 lbs. weight, in so fresh a 
condition that it passed muster when thrown out on the quay 
without exciting suspicion in the mind of the purchaser. The 
colours of this fish—the only individual I have ever seen caught 
on a hook—when first taken out of the water were most beautiful, 
the upper parts being of a deep-rich purple, shading on the sides 
through mauve into the white of the belly; within half an hour, 
however, these tints faded away, leaving behind only the ordinary 
dirty brown and white livery in which they generally come under 
the observation of naturalists. There was no sign of breeding in 
this specimen, which was caught during the month of January, 
1877, in thirty fathoms, mixed bottom. They are generally 
washed ashore in a dead or dying condition, and are not used as 
food on the north coast, being looked upon with great disgust by 
the fishermen, who invariably kill them and throw them over- 
board. 

[ Trachinus draco.—In Miss Cusack’s History of Kerry, p. 443, 
Dingle Bay is given as a habitat of this fish. This is no doubt a 
repetition of Andrews’ record in Dublin Nat. Hist. Proc., vol. 1. 
p. 122; Paper read 1854. The list of Kerry fishes was contributed 
by him, but no specimens were ever sent to Dublin. | 

Trachinus vipera.—In the Zoologist for Jan., 1876, I mentioned 
the fact that this species will rise to a small white fly, from per- 


Oagi1tBy—On some Irish Fishes. 5138 


sonal experience, not from hearsay, as the text, p. 82, would lead 
one to believe; but in all the cases in which I caught them thus, 
the sun had been some time set, so that it was difficult at a glance to 
distinguish between this and the young coalfish for which I was 
angling. It is known at Portrush by the suggestive name of 
“brute.” On our coast the usual remedy applied to cure its 
wound is to prick the puncture until it bleeds freely, and while 
the blood is flowing immerse the affected part in spirits of turpen- 
tine or whiskey. I have been pricked several times, but I never 
felt any inconvenience, so much depends on the state of health of 
the sufferer. So numerous are they sometimes that I took thirty- 
five, one of which was 6? inches long, during two hours’ shrimping 
by night, in the ladies’ bathing-place, Portrush. 

Scomber scomber.—Common at Portrush, from July to Septem- 
ber inclusive. Owing probably to some local cause, they appear 
earlier and in larger numbers at Ballintoy to the eastward, and 
Magilligan to the westward. Numbers of small mackerel were 
taken on the Donegal and Dublin coast during December, 1882. 
I have never previously remarked them at that season. Young 
fry, up to 4 inches long, are caught at Portrush in August. 

[ Scomber cohas.—In the Dublin Nat. Hist. Soc. Proc., vol. i. 
p- 106, Andrews records one sent to him, but without stating from 
whence it came. In Miss Cusack’s Kerry he gives the locality as 
“off Tearaght Island, county of Kerry,” but the fish does not 
seem to have been satisfactorily identified ]. 

Orcynus thynnus.—In the record of this species, p. 97, two 
distinct occurrences seem to have been confused together. ‘Three 
Irish examples are now authenticated as follows :—(1) Dr. Jacob’s, 
caught off Dublin Bay about the year 1828, and measuring about 
2 feet; (2) William Thompson’s, which came ashore living, in 
Ballyholme Bay, near Bangor, county of Down, in the autumn — 
of 1841; it measured 8 feet 3 inches long, 5 feet 4 inches in girth, 
and weighed fully 300 lbs. ; (8) my own, hitherto unrecorded. This 
example was obtained at Portrush on the Ist September, 1878 : its 
total length was 8 feet; girth 5 feet 1 inch; length of head to 
total length as 1 to 4; weight computed at as between 3 and 4 
ewts. Its stomach contained a number of mackerel in different 
stages of digestion, and about a quart of thick brownish-red fluid 


matter. We had been for some time aware of the presence of 
2X2 


O14 Scientific Proceedings, Royal Dublin Society. 


several large fish in the bay, from seeing them shoot along the 
surface in pursuit of the shoals of mackerel, glassan, and lythe, 
and after the capture of this example others presumably of the 
same species were observed, so that it is probable that a small shoal 
of tunnies had visited us, attracted no doubt by the abundant 
supplies of food obtainable, for which that year was especially 
remarkable. The individual in question was, it is supposed, 
frightened by an incoming steamer, and passing through the 
harbour mouth, traversed its entire length, and stranded with such 
impetus as to jamb itself between the dock-wall and a sunken 
lighter, where it was easily despatched. It was carried about 
from village to village as a show, until it became a nuisance, and 
was finally buried. [One taken off Dingle in December, 1883, is 
in the Dublin Museum of Science and Art.—A. G. M. | 

Thynnus pelamys.—Referring to the specimen preserved in the 
Andersonian Institute, and obtained from the neighbourhood of 
the estuary of the Clyde, Dr. Scouler is careful to state that it 
“could not be mistaken for Pelamys sarda (vide Thompson, Nat. 
Hist. Ireland, vol. iv. p. 95); and I cannot see any reason for 
doubting his correctness. Yarrell’s 33-inches example, of which 
I see no notice in the 38rd edition, can hardly have been the Cork 
(Bennett’s Court) fish, which is distinctly stated to have been 
294 inches long, 21 inches in girth, and 19} lbs. weight. The 
specimen from Wexford has long ago perished, but Mr. More 
informs me that one taken near Clifden, county Galway, in the 
autumn of 1883, is in the Science and Art Museum. 

Centrolophus pompilus:—In Miss Cusack’s Kerry, Andrews 
records this fish as found in Brandon Bay, Dingle Harbour, and 
off the Skelligs. ‘The only example of which I have any know- 
ledge was forwarded by the late Mr. W. Andrews to the Museum 
of Science and Art, Dublin, where it is now preserved in spirit; it 
had previously been salted by a fisherman, and is referred by 
Mr. More, the curator of that Museum, to the above species. 

Brama raii.—In the month of July, 1878, an example of this 
rare fish was washed ashore dead, but in a perfectly fresh condition, 
on the east strand, Portrush, after a severe north-westerly gale. 
Though the person who picked it up would not part with it, he 
kindly allowed me to make such an examination of it (comparing 
it with Yarrell’s and Ginther’s descriptions) as sufficed to 


Ocitpy—On some Irish Fishes. 515 


thoroughly satisfy me of its identity. The length was 15 inches, 
and the dorsal and caudal fins were considerably injured. I was 
subsequently informed by its finder that it was “very good eating”’. 
I may mention in this connexion that Thompson does not state 
that this fish specially is called “hen-fish” in Ireland, and that 
Tramore is the name of the locality whence Dr. Burkitt received 
his specimen. M‘Skimmin was undoubtedly wrong in his identi- 
fication. 

Schedophilus medusophagus.—During the second week of August, 
1878, I obtained a fine specimen of this fish, the first recorded from 
the British seas, which was taken in a salmon net, at Portrush, and 
measured 91 inches. For further particulars see Dr. Giinther’s 
account in the Trans. Zool. Soc., vol. xi. part vii1., p. 223, 1882. 

Lampris luna.—The fish taken in the Foyle during July—not 
June—1835, was Zeus faber, as stated in the “ Ordnance Survey of 
the parish of Templemore, county of Derry;” and as shown by 
the fin rays given, D. 9 (spinous), p. 13 (vide infra, Z. faber). The 
example of June, 1849, cannot be said to have been taken “in 
Derry,” having been caught at Innistrahull, off the Donegal coast. 

Caranx trachwrus.—Called “rock herring” at Portrush, where 
it is very irregular in its visits. During eight years’ acquaintance 
with that coast, it occurred but once, in the autumn of 1878, when 
vast shoals appeared following the herring fry, which on many 
occasions were driven ashore in such numbers that they were lying 
heaped up in masses several inches deep at the edge of the tide 
while their pursuers were caught in small seines by actual cart- 
loads, and hawked about the neighbourhood at almost nominal 
prices. So plentiful and fearless were they that I caught, within 
an hour, eight dozen scad and mackerel with my hands, while 
wading in water up to my knees. 

Naucrates ductor.—Crookhaven (in Cork) is the name of the 
place where the only Irish example was obtained. _ 

Capros aper.—The first announcement made by Andrews of 
the capture of this fish occurs in the Dublin Nat. Hist. Soc. Proc., 
vol. ii., p. 104, and was read April 9, 1858, when the capture was 
probably recent. This example was “taken in a trawl off Ventry 
harbour.” There are two specimens, both presented by Mr. 
Andrews, in the Dublin Museum of Science and Art, but they are 
not dated. Im Miss Cusack’s Kerry, p. 443, Andrews gives 


516 Scientific Proceedings, Royal Dublin Society. 


“Dingle Bay,” but does not mention how many specimens were 
obtained, nor date of capture; and as Ventry harbour opens 
into Dingle Bay, this is probably the old record reproduced in 
a different form. Such carelessness is very reprehensible, and 
materially increases the difficulty of obtaining reliable records in 
all branches of Irish natural history. 

Zeus faber.—Dorees are by no means common about Portrush, 
where such as are obtained are chiefly taken by the trawlers. They 
are of small size, about 2lbs. being the average, and 4 lbs. the 
largest I have ever seen there. In the ordinance survey of Temple- 
more (v. supra, Lampris luna) this fish is mentioned as having 
been taken on the 9th July, 18385. All the species included in this 
report are stated to have been captured “in or above the salmon 
nets at Culmore,” some twenty miles above the mouth of the 
Foyle. 

Scicena aquila.—The single Irish specimen was caught opposite 
the town of Passage, which is above Queenstown, Cork, and quite 
six miles from the entrance to the harbour. (This mistake pro- 
bably arose from the omission of the capital letter in Thompson’s 
Nat. Hist. of Ireland, vol. iv.; p. 90.) 

Trichiurus lepturus.——Mr. More tells me that the first Irish 
specimen was recorded by the late Dr. A. Leith Adams from 
Kinsale, county of Cork, in the Fie/d for January 28, 1871. In 
the Dublin Nat. Hist. Proc., vol. vi., p. 68, Andrews also gives the 
date as January, 1871; and in Miss Ousack’s Kerry the record 
is given, “five specimens obtained in Brandon and Tralee Bays 
(Dr. Bustead).” 

| Obs. — Lepidopus caudatus.—Ball, in the Nat. Hist. Review, 
vol. ii., p. 45, gives it as a “probable occurrence”: only a head 
was examined. Couch mentions, no doubt, the same example. 
For the present it can scarcely be included in the Irish list. | 

Gobius ruthensparri.—Thompson (p. 116) records the example 
taken from the stomach of a tern. It is remarkable that I never 
obtained a goby of any species at Portrush. 

Gobius niger.—Mr. More is of opinion that Thompson’s Tory 
Island specimens belong to this form, not to G‘. paganellus, to which 
latter all the other localities are to be assigned. 

Callionymus lyra.—I have taken the male at Bray, county of 
Wicklow (where they are called “‘sandfish”’), on a line set for 


OcitBpy—On some Irish Fishes. 517 


flukes, and baited with lug-worm, in five fathoms of water. The 
females are sometimes common in Portrush harbour during 
summer and autumn; but I never caught a male there. They 
are somewhat uncertain in their appearance, being numerous in 
some seasons and scarce in others. (Achill Island.—A. G. M.) 

Oyclopterus dumpus.—Adult examples are occasionally taken in 
the salmon nets at Portrush during April and May, but they are 
never common. During the summer and autumn months I have, 
however, frequently taken the young, of from half an inch to an 
inch in length, adhering to crab-creels and tangle. 

[ Liparis vulgaris.—We do not think that this species has any 
claim to a place in the Irish list. | 

Anarrhichas lupus.—The records of this fish as Irish are not 
very satisfactory. Templeton only mentions having seen them in 
Belfast market, and merely conjectures that they may have been 
caught in the Bay. I never saw or heard of one in the Portrush 
market. Dr. Jacob’s record is possibly correct, as may be also 
Dr. Ball’s; but in no case is it positively proved where the ex- 
amples were captured. There has not been any native specimen 
in the National Museum within Mr. More’s recollection, that 
alluded to by Thompson having disappeared. 

Blennius galerita.—Dr. Day has transferred the Irish localities 
of this species to Carelophus ascanni (see below), a fish which Mr. 
More has not personally taken. The announcement of the dis- 
covery of Montagu’s blenny on the Irish coast runs thus: “Several 
at Dingle harbour, 1868 ; coast of, and islands off, Connemara, 
1869.” (A. G. More, in Zoologist, 1878, p. 297.) 

Blennius pholis.—It is not necessary that the water should flow 
at every flood into the rock-pools frequented by the shanny, since 
I know many haunts, which only receive an accession of sea water 
during stormy weather or exceptionally high spring-tides. This 
species is more numerous and of larger size in shallow pools along 
the rocky shore to the north of Inver, Donegal Bay, than I have 
met with it elsewhere. 

Carelophus ascanii.—Since noticing the above species in the 
Zoologist for January, 1876, I obtained so many examples from 
crab-creels during the warm months of that and the two following 
years, that I consider it quite as numerous as Blennius gattorugine, 
with which it is usually found associated, They are only taken 


o18 Scientific Proceedings, Royal Dublin Society. 


in fairly deep water where the bottom is rocky and weedy. All 
those over five inches had lost the transverse bars, which I there- 
fore take to be a sign of immaturity. The Dalkey and Neweastle 
fishes—Yarrell’s Wicklow (Dublin), and Down records—though 
possibly correct, rest on insufficient authority. Transfer More’s 
records to B. galerita. See under that species. 

Centronotus gunnellus.—As local names, it is called “‘ nine-eyes” 
at Portrush; “nanny nine-eyes” at Bray; and, according to 
Thompson, “clavin” and “ flutterick”’ in the north; “ coddick” 
at Carrickfergus (J. Doo); and “lamprey ” at Roundstone (fide 
M‘Alla). 

[ Obs.—Zoarces viviparus.—Templeton’s record is insufficient ; 
and we are, therefore, of opinion that this fish should be omitted 
from the Irish list: and indeed it is one of those eastern species 
which need hardly be expected on our shores. | 

Cepola rubescens.— Dr. Farran’s specimen was obtained at 
Stradbally, county of Waterford. It is exceedingly doubtful 
whether the report of its abundance in that locality is correct, 
resting as it does on the unsupported testimony of fishermen alone. 
(Often found in the stomach of turbot; also taken off Howth and — 
in Dublin Bay.—A. G. M.) 

Trachypterus arcticus.—Mr. William Darragh, of the Belfast 
Museum, kindly writes me, under date Dec. 14, 1883, that the 
Donegal example, when received, was in so advanced a state of 
decomposition, as to be unfit for preservation. (See Zoologist, 1875, 
p. 4348). 

Atherina presbyter.—Small examples—two to three inches long 
—when split longitudinally into four pieces form an irresistible 
bait for pollock, glassan, and all other fishes, which can be caught 
by whiffing. 

[ Obs.—Mugil capito.—In addition to Dr. Harvey’s statement in 
the Fauna of Cork, Professor M‘Coy (Ann. Nat. Hist., vol. vi., 
p- 403) records this species from Dublin Bay. Requires proof. 

Mugii chelo.—All the mullets—many scores—which I have 
examined from the coast-line between Lough Foyle and Belfast 
belonged to this form. Mr. More’s experience of specimens from 
the shores of Dublin, Cork, and Kerry is similar. 

Gasterosteus aculeatus.—I have examined numbers of these 
little fishes from many northern localities, varying in elevation 


OcinBy—On some Irish Fishes. 519 


from drains opening into the sea, but not entered by the tide, to 
streams and ponds up to 700 feet above the sea level, and in every 
case but one, they belonged to the var. gymnurus ; the one excep- 
tion, var. brachycentrus, was obtained in a stream near Donemanagh, 
county of Tyrone, and measured three inches. From this, and 
probably from many others of our. northern streams, the sprickly- 
bag, as it is here called, has been almost entirely banished by the 
reprehensible practice of turning flax-water into the rivers; how- 
ever, they still exist in numbers in the small streams, ponds, and 
drains, where this pollution does not occur. 

- Gasterosteus spinachia.— Known at Portrush as “ horn-eel,” 
from a fancied resemblance to Belone vulgaris. 

Labrus maculatus. — Called ‘“ rock-bream” at Bray, and 
“merrin ” at Portrush, where Z. mirtus is distinguished as 
“‘merrinroe.” They are specially sought for on the north-coast 
as bait for crab, lobster, and buckie-creels, and also for conger 
and deep-sea lines, the method employed being as follows :— 
Strong, but fine, boulters, known as “ merrin lines,” baited with 
buckies and hermit-crabs, are set on a rocky weed-covered bottom, 
about an hour before the turn of the tide, and are taken up before 
the new tide has time to set down upon the line, since, should it 
do so, the masses of tangle on which the line rests, being reversed, 
would cover the line, and thus probably cause its loss, or at any 
rate strip it of all its hooks. The wrasses are also salted and 
kept for winter use both by the fishermen and country people 
living near the shore, and are considered good food. 

Labrus mixtus—Not uncommon at Portrush, where it is taken 
in the same manner as the preceding species. The largest example 
measured 124 inches. 

Ctenolabrus rupestris.—Myr. Blake Knox’s assertion (Zoologist, 
1866, p. 506), that this wrasse is so abundant in Dublin Bay as to 
merit a local proverb and name must, I think, be looked upon 
with some suspicion. I have caught many dozens of small wrasses 
on the Dublin coast, but all were either Crenilabrus melops or the 
young of Labrus maculatus ; and it is a significant fact that our 
National Museum does not yet contain a native spécimen, though 
we would be only too happy to see it there. Barncleugh is on the 
coast of Northumberland, and Selby’s example was, therefore, 
English, not Ivish. 


020 Scientific Proceedings, Royal Dublin Society. 


Gadus morrhua.—Both the cod and the ling, Molwa vulgaris, 
are greatly subject to blindness, the eyes of those thus affected 
being entirely covered with a thick bluish skin; this, however, 
does not in the least affect their condition. On the north coast 
the fishery is carried on from October to March inclusive, but usu- 
ally all have spawned by the end of February. So sensitive are 
they to the approach of bad weather, that they leave the banks and 
retire to the deeper water outside, about three days previous to 
the commencement of a gale. The young, about an inch long, 
are common during June and July under Meduse floating sea- 
weed, &e. Those of medium size, from 3lbs. to 8lbs. in weight are 
called “ half-guages” at Portrush, and “‘ buddaghs” at Portaferry. 
During the winter of 1877-78 I caught a cod which had no trace 
of a pectoral fin on one side externally, but internally there was 
a hard lump. Cod taken on rocky or mixed ground are superior 
to those from sandy or muddy ground: probably owing to the 
more abundant supply of crustaceous food. 

Gadus eglefinus.—Prior to 1865, haddocks were very numerous 
at Portrush, where the lines set for them were baited with various 
Helices. About that year they deserted this part of the coast, and 
did not appear again in any quantity till 1877, when shoals of 
small fish arrived during the summer, in company with whiting. 
The same desertion and return has been noticed in Dublin Bay. 
Larne Lough mostly supplies the Belfast market. 

Gadus luscus—Common at Portrush, frequenting rocky and 
weedy ground, and called “maggelagy.’’ Two, which I captured, 
measured—(1) Oct. 17, 1877: length 183 inches; weight 4 lbs. ; 
prime. (2) July 20, 1878: length 182 inches; weight 34 lbs. ; 
out of condition. Large examples, when prime, are quite equal to 
haddock and whiting for the table. 

Gadus minutus.—Very common at Portrush, where it is con- 
founded with the young of G. /uscus, frequenting sandy spots near 
rocks and weeds. ‘They are found in Kingstown harbour, east 
coast.—(A. G. More). I have seen no example exceeding six 
inches in length. 

Gadus merlangus.—On the north coast the lines are always set, 
if possible, along the edge of the coarse ground, the best baits 
being pieces of garfish or launce, in lack of which whelks or hermit- 
crabs are used. Since Thompson’s time we have, I presume, had 


Ocitpy—On some Irish Fishes. 521 


our taste educated, as I always find whitings selling well, which 
occasions a regular fishery for them from October to January on 
parts of the Derry coast. After having been scarce for many years, 
they became abundant, along with the haddocks, in 1877. 

Gadus poutassou.—In the Dublin Nat. Hist. Soc. Proceedings, 
1865, vol. iv., p. 9, Mr. William Andrews records this fish, under 
the name of Werlangus albus, as having been noticed by him in the 
Claddagh market at Galway. But this specimen unfortunately 
was not preserved, and thus the identification remains doubtful. 

Gadus pollachius.—The young, up to 6 inches long, are called 
“rackies”’ at Portrush. Young eels about 4 inches long, which 
have been steeped for some time in brine, form an excellent 
bait for whiffing, while boiled limpets and crabs are excellent for 
bottom fishing. My largest examples weighed — (1) 15 lbs., 
caught by whiffing, August, 1877; (2) 173 lbs., caught on a cod 
line, March, 1878; (3) 213 1bs., caught as preceding, April, 1878, 
in about thirty fathoms water. 

Merluccius vulgaris.—So rare on the coast about Portrush, that 
I have never seen an example, and have heard of only one, which 

occurred many years ago. 
Phycis blennioides—The earliest authentic Irish record of this 
fish is Templeton’s, who obtained it among haddock (in Belfast 
market ?) on the 24th January, 1812. There is also an example 
in the Dublin Museum of Science and Art from the Ordnance 
Collection, but no locality or date is mentioned, though doubt- 
less it came from the north of Ireland. 

Molva vulgaris.—On the Derry and neighbouring coasts, ling 
and cod are sought for together, the fishery for conger being car- 
ried on in a different manner. The boutlers are here baited 
alternately with a slice of fresh fish and a whelk, the former being 
considered better for ling, the latter for cod. Young ling are 
caught frequently on the “merrin-lines” during summer and 
autumn at Portrush, generally about one foot long; and, as 
Thompson mentions and describes a young fish of about that 
length taken in January, it would appear that there must be 
a considerable variation in the date of their spawning at different 
localities. The season continues from December to April with us. 
In May they are little fished for, and are for the most part 
spent. 


522 Scientific Proceedings, Royal Dublin Society. 


Motella mustela.n—Not nearly so plentiful about Portrush as 
MW. tricivrata, and only obtained of small size and between tide- 
marks. 

Motella tricirrata.—At Portrush called “catfish”? in conjune- 
tion with the last species. JI have never known of one taking 
a hook, but numbers are caught in the wicker crab-pots during 
the spring months, when these are first laid down, their sense of 
smell being so powerful, that a very few days suffice to exhaust 
the locality. These examples, being all of large size, pay the 
penalty of their temerity by themselves forming a bait for the 
creels. Immature examples are often obtained in four to six 
fathoms water in the buckie creels in winter; these are unspotted 
to at least six inches long. 

Raniceps raninus.—In addition to those mentioned by Dr. Day, 
I learn from Mr. A. G. More, that Mr. Andrews forwarded two 
other specimens to the Museum of Science and Art, Dublin :— 
(1) Dingle Bay—the second recorded by him from this locality— 
caught in thirty fathoms, 1856; (2) Dalkey Sound, June, 1856. 
My two recorded examples from Portrush have been confused: 
their records should run thus:—(1) Second week of November, 
1875, length 83 in.; (2) 15th March, 1876, length 43 in.; these 
two are also in above-mentioned Museum. A third example, like 
the others, washed ashore dead, but in this case in a badly muti- 
lated condition, occurred to myself on February 16th, 1878, at the 
same place. (Kor Sir J. Corrigan, read Sir D. Corrigan.) 

Brosmius brosme.—This species should be omitted from the 
Trish catalogue, there being no reliable evidence of its occurrence. 
The name Torsk or Tusk is often given to codfish. 

Ammodytes lanceolatus.— Frequently takes a small white fly 
(or a small strip of white leather.—A.G. M.), especially towards 
evening, when the shoals are drawing inshore to their usual hiding 
places. About two days after a severe N.-W. gale, which occurred 
in January, 1876, large numbers of this species were found on the 
east strand, Portrush, about fifty yards above high water-mark, 
buried in the sand, from which their heads protruded about an 
inch, having evidently being driven in to this unusual distance by 
the violence of the waves. I have seen several twelve inches 
long. 

Hippoglossus vulgaris—A few are taken yearly at Portrush 


Ocgirpy—On some Irish Fishes. oe 


during the sprmg mouths. ‘They are also used as bait for the 
deep-sea lines, as cod and ling are said to be very partial to their 
flesh. Small examples (up to 50 Ibs.) are excellent as food. In 
the stomach of one taken in March, 1878, were several lumps of 
boiled beef and two large bones, the whole weighing nearly 8 lbs. 
Thompson mentions an Irish example from Ballywalter, in the 
county Down, which exceeded 300 lbs. Called “halibut” in the 
north. : 

Rhombus maximus.—With us, the bait considered best for turbot 
is a piece of the flesh of a conger which has been hung for several 
days in the open air, so as to become partly stale. The largest 
which I have obtained weighed 36 lbs. Legislation is greatly 
needed to put a stop to the reckless destruction of the young fry 
of this species and its allies by shrimpers. I have returned to the 
water thousands of turbots, britts, plaice, flounders and soles, by 
sumply gathering up the leavings of these people. 

Rhombus levis—Thompson’s statement, that this species out- 
numbers its larger relative by about four to one, must be qualified 
as regards Portrush, for here the two species are about equally 
plentiful. On the 4th June, 1881, I obtained a very curious 
monstrosity. The head was horned, similarly to the specimen 
figured by Yarrell (vol. i., p. 648), but the protuberance was even 
longer, and the lateral line branched off anteriorly into two parts, 
one running forward to the end of the horn, the other bending 
‘downwards along the snout. 

Zeugopterus punctatus.—In addition to those mentioned by 
Dr. Day, I have to record two examples obtained at Portrush, 
both taken in crab-pots:—(1) April, 1876, length 63 in.; (2) 
_ August, 1877, length 43 in. Thompson’s two recorded Dublin 
examples—Carmichael’s and Warren’s—were not obtained in the 
market. (The Museum of Science and Art, Dublin, possesses a 
specimen from Dingle, county of Kerry, presented by Andrews.— 
J (Ge Ni) 

Arnoglossus megastoma.—In June, 1881, I obtained in the Bel- 
fast market a small example, which had been forwarded with other 
flat fishes from Magilligan, county of Derry, and was the only one 
I ever saw trom that district. ‘lhe lateral le was shaped as in 
the figure of Z. velivolans, Yarrell, vol. i., p. 606. (Common in the 
Dublin market.—A. G. M.) 


024 Scientific Proceedings, Royal Dublin Society. 


Arnoglossus laterna.—The hundreds mentioned by Mr. Blake 
Knox (Zoologist, 1866, p. 508) as landed in Dublin from trawlers, » 
if correctly identified, may have been captured at a considerable 
distance, and do not necessarily belong to the Dublin coast. 
Andrews obtained specimens from Dingle and Ballinskelligs 
Bays, and forwarded one to the Dublin Museum of Science and 
Art. 

Pleuronectes platessa.—‘‘ Spotty fluke” about Portrush. Out 
of two-score large plaice from Glenarm, county of Antrim, which 
I observed in the Belfast market on June 16th, 1881, no less than 
five were coloured on both sides; one of these was slate-blue, the 
orange spots, however, being on the upper side only. Very 
large examples, from 8 lbs. upwards, rarely take a bait, the 
stomachs of those which I have examined being invariably filled 
with shells. With the first fine weather in spring, large shoals of 
plaice, from 1 lb. to 3 lbs. in weight, draw inshore, and as they take 
a bait greedily, these “scull-flukes”’ are eagerly sought, a mixture 
of lug- and rag-worms, shrimps, razorfish, hermit crabs and cuttle, 
being used as a bait. I caught a very handsome example at Bray 
in August, 1872, in which the spots on the upper surface were ex- 
ceptionally large and brilliant, while the under surface was beauti- 
fully marbled with white, buff, and olive green. 

Pleuronectes microcephalus. —“ Bastard-sole”’? at Portrush ; 
‘“lemon-”’ and ‘‘maiden-sole” in the Belfast market, where it 
frequently occurs. 

Pleuronectes cynoglossus.—Yarrell mentions a skin of cone from 
the Firth of Forth measuring 19 inches. 

Pleuronectes imanda—On the 38rd November, 1877, I caught 
my two largest examples, measuring 143 in. and 14 in., and | 
weighing 213 oz. and 18 oz. respectively. Dabs caught on mixed 
ground are of a finer flavour than those from sand or mud. They 
are used as bait for the conger lines, for which purpose they are 
unequalled, as also they are for lobster-creels; they are frequently 
caught with a piece of whelk, a bait which their congeners will 
rarely look at. I have never met with the fry of the dab among 
the debris of the shrimp-nets. 

Pleuronectes flesus—I kept two small flounders, taken from 
muddy ground, and therefore of an immaculate dark brown colour 
above, in a bath, the bottom of which was white, and in which; no 


OcitBy—On some Irish Fishes. 525 


foreign substance was placed, and within a week they had become 
pale grey, with some scattered brown spots. 

Solea lascaris—Seems to be rare on the Irish coasts; it has 
never occurred personally to either Mr. More or myself. 

Solea variegata.—I may remark that in Thompson’s specimen, 
obtained in Belfast Lough, 18th June, 1838, the rays of the D. and 
A. fins are in both cases less than the number given by Day, being 
only 63 and 49. In the Ann. & Mag. of Nat. Hist., vol. vi. 
p- 405, Professor M‘Coy states that this species is found in toler- 
able abundance off Dublin Bay, between the Kish lightship and 
the harbour. 

Solea lutea.—The first example preserved, though not recorded 
at the time, seems to have been Ball’s, from Youghal, county Cork, 
taken in October, 1834 or 785; (2) Three taken by Thompson and 
Hyndman off Dundrum, county Down, 23rd August, 1836; (3) 
Four by Hyndman in Belfast Lough, 18th June, 1838; (4) By 
M‘Calla, off Dublin Bay and coast of Down, in or prior to 1840; 
(5) A few off Bundoran, Donegal Bay, by Thompson, July, 1840 ; 
(6) By M‘Coy, along with the last species (which see) ; (7) Off the 
Dublin coast by Ball, no date given. The largest Irish specimen 
recorded measured 43 in., and two examined by Thompson had 
76 rays in the D. and 58 ain 59 in the A. fins, respectively, these 
numbers exceeding the maximum given by Dr. Day. 

Salmo salar.—In the Foyle tributaries the fry of all the Salmoni- 
dee, before putting on the migratory dress, are known as “‘Jinkins.” 
After the anadromous forms have assumed the silvery dress, simply 
as “fry.” During the season of 1884, the fisheries in the Foyle 
above Londonderry were ‘exceptionally poor, a fact which was par- 
tially attributed to artillery practice having taken place in that 
city at the time when the main body of fish were running up the 
river. In the summer of 1876 I saw a curiously deformed salmon 
taken at Portrush, which, owing to spinal disease, had the back so 
much humped that its girth in front of the rayed dorsal was exactly 
the same—19 inches—as its total length. During February and 
March numbers of small dark-coloured fish! run up the Burnden- 


1 Owing to the date of their appearance, I have never been able to obtain a speci- 
men for examination; but it is possible that these may be a barren variety, similar to 
those observed in the Rhine by Barfurth. 


526 Scientific Proceedings, Royal Dublin Society. 


net, a tributary of the Foyle in the county Tyrone, where they do 
great harm by rooting up the redds of larger fish, previously 
spawned, either in order to consume the eggs and fry, or to make 
their own redds. There can be little doubt that the fisheries. 
would be improved if these and all other salmon remaining in the 
river were allowed to be caught after the loth February, at which 
date the. season might commence. On the other hand, the 
month of October might be advantageously added on to the close 
season, since the main body of the trout and sewin spawn during 
that month, and are certainly not in good condition for the table. 
After spawning is over, the kelts consume, on the average, at 
least a dozen fry per diem, almost all of which are young salmon 
and sewin, which are then dropping down the river. Granting 
that but one-half of these are salmon-smolts, every kelt which 
remains in the river for one hundred days after February 15th— 
not an inordinate assumption—consumes six hundred salmon-fry ; 
reducing this number again by one-half, to allow for losses which 
might have occurred from other causes during the perils of migra- 
tion, we arrive at a dead loss to the fishery of three hundred grilse, 
which, on their return in a few months, would have weighed 
about 1000 Ibs. : against which we have only a single kelt, which, 
if it should have chanced to escape the dangers of the sea, would 
have returned the larger by 4 lbs. or 5 lbs. During the summer of 
1875 I took from The Bush, county Antrim, a grilse of about 4 lbs., 
which was so completely covered with fungus that on the fins and 
part of the head alone was the skin visible; this fish was fresh-run, 
and taken not a mile from the sea. ‘The following fact seems to 
prove that salmon do not invariably breed annually :—In January, 
1878, numbers of salmon were seen, and one actually captured 
with a gaff, leaping and sporting on the surface, about five miles 
out to sea off Portrush, county Antrim. The captured fish proved 
to be in perfect condition, showed no signs of breeding, and 
could not therefore have intended so doing that winter. This, and 
presumably those in company with it, were Foyle fish, which are 
easily distinguished from those which ascend the Bann. The 
large salmon, too, which run up our rivers early in spring, could 
hardly have spawned during the preceding winter and so quickly 
_ have recovered their condition. It is probable that local, or even 
individual causes, which may be either temporary or persistent, 


Oairpyv—On some Irish Fishes. 527 


may induce fish to become annual or biennial breeders, according 
to circumstances. On the 30th April, 1883, I caught a small 
female salmon in Lough Ashe, county Tyrone, in which the ova 
were ready for extrusion. This Lough has no outlet to the sea, up 
which fish could make their way, and the individual in question 
was undoubtedly one of the number of fry put in from the adjacent 
stream just two years previously. There can be no doubt that this 
fish would have shed its spawn in the feeder of the Lough—at the 
very mouth of which it was taken—and it would seem to show that 
a small non-migratory race might be propagated in this and many 
other loughs, where there is sufficient space and food. The fish 
was in good condition, and as silvery as if fresh run from the sea; 
it is now in the British Museum, and has been examined by 
Dr. Day. During the spring of 1875 I saw three salmon in the 
Dublin market, weighing respectively 58, 55, and 53 lbs., and 
all three were said to have been taken at one haul of a net in the - 
Shannon. 

Salmo trutta.—Known in the north of Ireland as “ white 
trout” only. The variety cambricus is alone found in our north- 
ern rivers, and of this we also have a long-headed and short-headed 
form—a difference, however, which will be found on dissection to 
be greatly attributable to sex, the short-headed being, as a rule, 
females, and of the two much the handsomer fish. Once only have 
I captured a “‘sewin”’ in the open sea, on a sand-launce, while whip- 
ping for pollook at night outside the Skerries, off Portrush. Of the 
fry placed in Lough Ashe, as mentioned above, in, the spring of 
1881, I took several in 1883, which proved to be ‘“‘sewin”’; they had 
increased in size to nearly 1 lb. average weight, had retained a 
more or less silvery colour, but had gained a few dark-edged red 
spots above the lateral line; they were,in May, in magnificent 
condition, and of flavour superior to the fresh-run autumn trout ; 
two of them contained ova about the size of turnip-seed. The 
largest “sewin” which I have handled weighed 83 lbs. 

Salmo fario.—The “estuary trout”’ of the northern rivers, which 
is here known as a “dolachan,”’ is, I believe, a large brook trout, 
which lives for the most part on small fishes, and resides during 
the greater portion of the year in the tidal reaches, making its way 
into the upper waters of our streams about October, where they | 
feed principally upon the fry and eggs of their congeners, of which 


SCIEN. PRUC. 2:D.S.—VOL. IV. PY. IX. DONG 


528 Scientific Proceedings, Royal Dublin Society. 


they consume an incredible amount. ‘They are seldom taken under 
2 lbs. weight, and I consider these overgrown trout the worst enemy 
with which the salmon have to contend in these rivers, not even ex- 
cepting an old male kelt. These “ estuary’’ fish do not resemble any 
of the figures in Dr. Day’s work, their colours being as follows :— 
For about two-thirds of the length below, and one-third above the 
lateral line, the body is thickly studded with brick-colowred spots 
about the size of a threepenny piece, the upper parts being covered 
with similarly-sized brown spots; while from head to tail there is a 
distinct lead-coloured longitudinal band, comprising about four rows 
of scales below, and two above, the lateral line.! These fish, though 
living so long in salt or brackish water, never assume a silvery 
appearance ; in fact, some of the most brilliantly coloured and 
spotted trout that I have ever seen, were taken in almost pure salt 
water, close to the mouth of the Bann. © 

From careful examinations made during the last three years— 
1882-’84—I find that although about 70 per cent. of our brook 
trout breed during September and October, there is no month 
during spring and summer in which some do not shed their 
spawn.’ While conducting the same series of observations, I have 
also arrived at the conviction that the size of the ripe ova cor- 
responds to the size and age of the parent fish. Mr. Meenan, of 
Belfast, writes me that the largest Lough Neagh trout, which he 
has received of late’years, weighed 27 lbs. 

Salmo alpinus.— Among local names should be mentioned 
“murneen,’ by which, according to Wilde, they are known in 
several of the Galway and Mayo lakes. Charr are common in 
many of the Donegal loughs, and these loughs have no appear- 
ance of a glacial origin, and in some cases at least, as in the 
small bog loughs of Innishowen, they are nowhere deep. I do not 
think that we have any positive proof that the disappearance of 
this fish from Lough Neagh is due to the agency of man; and it 
is remarkable that their disappearance from Inchigeelagh and 


1 In a male, partially spawned, killed October 3rd, 1884, there is but one tooth on 
the head of the vomer, and an irregular double row, in which many were wanting, 
along the body of that bone, a slight mandibular hook, fifty-eight vertebra, and only 
thirty cecal appendages ; teeth largely developed. 

® T have never had an opportunity of examining specimens from November to Feb- 
ruary, inclusive. 


Ocirpy—On some Lrish Fishes. 529 


Gougaunbarra—the “lakes at the source of the river Lee” alluded 
to by Professor Allman—occurred about the same date, and that 
from Loch Leven not long afterwards. Though, judging from 
well-known habits in its congeners, it is probable that charr would 
gladly make a meal of trout-fry and -ova; still the breeding haunts 
of the two species are so diverse, that they can hardly do much 
damage. ‘The lake near Dunfanaghy, mentioned by Templeton, is 
probably Sessagh, where Mr. Lucas, of Letterkenny, tells me they 
are found. ‘T'o him I am also indebted for the locality of Lough 
Veagh in the same county ; and Mr. Connison, of Londonderry, has ~ 
taken numbers with the fly in the Mindorin and Minteagh lakes 
of Innishowen. In Westmeath, Lough Owel, and in Wicklow, 
Luggela, must also be added, while it appears that, in Cork, Inchi- 
geelagh should not be expunged from the list of localities. They 
_ have lately been introduced into Lake Gartinardress, county Long- 
ford: jide W. J. Hamilton. ‘The usual size of Donegal examples 
is from 7 to 10 inches. 

[Osmerus eperlanus might be omitted from the Irish list. 
There can be little doubt that Thompson’s conjecture as to confu- 
sion existing between this fish and the Atherine is correct. | 

Coregonus pollan.—Dr. Day does not mention the occurrence of 
this species in salt or brackish water, though the fact is indisput- 
able, as the following, from four distinct localities, will show :— 
Two of these localities are recorded in the Fiedd. Whether their 
migration to salt water is unavoidable or intentional, remains an 
open question; but I certainly incline to the former opinion, be- 
lieving that heavy floods, with which these fish are not strong 
enough to cope, have swept them to the sea, where they have 
lost their reckoning, and hundreds have probably perished, for 
one that attained to a safe resting-place. ‘The first occurrence 
was recorded in the Fiedd of January 5, 1878, by the late Mr. 
Francis Francis, who obtained his examples from the coast of 
Cheshire, between the mouths of the Dee and Mersey, where they 
appear to have been taken in considerable numbers; and in the 
following issue of the same paper the identity of his specimens with 
C. pollan is fully established on the authority of Dr. Giinther, who 
personally examined them. Again, in the Meld of January 19, 
1878, Mr. R. G. Symes, of the Irish Geological Survey, records 
examples from the estuary of the Erne; it would seem also from 

2¥2 


530 Scientific Proceedings, Royal Dublin Society. 


the wording of his letter, that pollan are found in Lough Melvin, 
and the Bundrowes river. In addition to these localities it is well 
known in the estuary of the Bann, and I now propose to give a 
short account of its recent colonization of the estuary of the Foyle. 
Here they appeared first in 1881, but were scarce and of large 
size, while, in the following season, they were slightly more 
plentiful, about a dozen being taken at each tide, and up to the 
ordinary standard of size; but in 1883 they were much smaller— 
all those which I personally weighed scaling from 7 oz. to 9 oz.—but 
infinitely more numerous, as many as 7 doz. being not uncommonly — 
taken in a tide. In this year, positive proof of their breeding was 
obtainable, examples of about three inches long having been caught, 
and hundreds of others were seen to pass through the meshes. 
Owing to the unusual lowness of the river, consequent on the long 
drought, the season of 1884 proved exceptionally unsuccessful for 
all kinds of fishing, and it is not, therefore, surprising that the 
numbers of these fish which were taken were far less than in the 
preceding year; but it is remarkable that with the. decrease of 
numbers the increase of size again became most marked. Nothing, 
however, was seen of those which where bred last year, nor any 
sign of this year’s brood. The bay between Dunnalong and 
Magheramason points, on the Tyrone bank, is the only part of the 
river in which they seem to be permanently established, probably 
because at all states of the tide there is slack water there; it has 
for the most part a muddy bottom, but with occasional patches of 
stony ground. It isin this bay, about five miles above London- 
derry that they bred in 1883. Odd examples are captured in the 
nets, further up the estuary towards Strabane. Whatever may be 
the opinion of the edible qualities of the Lough Neagh pollan, 
these brackish-water fish, when obtained perfectly fresh from the 
net, are of excellent flavour. So full are they of oil, when in con- 
dition, that after having been kept for a few hours, it will see 
drip from them when hung up. 

Belone vulgaris. Rie eel is the only local name now in use 
in the Portrush district; never, so far as I can ascertain, “ spear- 
ling.” Here they are common during the autumn, but are more 
solitary than gregarious. The nets used are loosely hung within 
a wooden frame, about one yard square, and are anchored in eddies. 
They are almost the best bait for whiting and sea bream. They 


OaILBy—On some Irish Fishes. 5381 


run up the Foyle estuary to at least as high as Culmore. I have a 
note of one captured by myself in October, 1878, of 343 inches in 
length. (At p. 148, line 15, “latter” should be changed to 
‘‘former,”’ since it it is B. ocus, which wants the vomerine teeth.) 

[ Carassius vulgaris.—1 do not know of any mention of this. fish 
by Thompson. | 

Gobio fluviatilis—Add to localities: Dublin canals, and lakes 
and rivers near Killashandra, county of Cavan (W. J. Hamilton). 
For “ Dodden ” write “ Dodder.” - 

Leuciscus erythrophthalmus is very capricious in taking an 
artificial fly, occasionally snapping it up at every cast, and again 
on a day, to all appearance in every way similar, refusing to look 
at it, though rising in numbers all round it. I have found it best 
to use a single small bright fly, cast very light, and as soon as ever 
the fly lights upon the surface flick it off ; a calm bright day is the 
more suitable: I have caught thirty-two small rudd within an 
hour in this manner: In Leitrim Lough, a small pond near 
Donemanagh, county of Tyrone, many of the rudd have the 
upper lobe of the caudal slightly shorter than the lower. 

Leuciscus phorinus.—I have never seen minnows more abundant 
anywhere, not even in the Itchen, than they are in the main river 
and Kellswater, near Bellaghy, county of Antrim. Mr. W. J. 
Hamilton also tells me that they are common in some of the rivers 
of Cavan. I think that the theory of its introduction is excessively 
doubtful; its scarcity is more probably due to the nature of the 
country. 

Abramis blicca.—Not being found in Ireland, it seems probable 
that the local names given belongs to A. brama. 

Nemacheilus barbatula is unfortunately quite as good a bait 
on night-lines for large trout as for eels; numbers are thus caught 
in the rivers near Omagh: the county of Tyrone may, therefore, 
be added to the list; as also may Kilkenny, Wexford, Clare, 
and Galway. 

Olupea alosa?—A fish called the “craig herring” is taken in 
the Foyle during the latter part of June and July: sometimes as 
many as eight in a tide. This year, 1884, only one was taken, 
which I failed to see. As it is said to grow to 5 lbs. weight, I pre- 
sume that it must be this species, rather than C. finta. 

Anguilla culgwis.—In our rivers eels do not as a rule hiber- 


b) 


532 Scientific Proceedings, Royal Dublin Society. 


nate; at least I have caught numbers of all sizes by setting night- 
lines in deep still holes during each of the winter months. Here, 
in the north, the skins are considered excellent as bandages in 
cases of sprain. Since forwarding the note published by Dr. 
Day—vol. iii., p. 249—I have examined several specimens from 
the Burndennelt, which are exactly intermediate in the measure- 
ments, as given in the last edition of Yarrell, between the so-called 
A. latirostris and A. auctirostris. Alluding to the mortality among 
eels in the Lagan—vol. iii., p.248—Thompson is misquoted: he does 
not say the “three previous days,” but “three successive days in 
the previous month.” 

Conger vulgaris.—Congers are sought for at all seasons on the 
north coast, but more especially in spring and autumn. During 
the winter they are often taken on the cod-lines set some distance 
off shore, and these examples are never more than 20 lbs. in 
weight, and are always light-coloured. They are known as “ scull- 
congers,”’ and their appearance is always hailed with much satis- 
faction, not only because they command a higher price in the 
market than cod and ling, but also that when cut up they form the 
best bait for, and ‘are supposed to denote a plentiful supply of, 
those fish. The fat round the intestines is used as an external 
remedy in cases of rhumatism and kindred diseases, being rubbed 
well into the parts affected. Large ones, preserved with brown 
sugar and pepper, and dried in the sun, are excellent if cut thin 
and fried like bacon. ‘Thompson only mentions £3 as the value 
of nets destroyed in a single night, not £5. I am told by a trust- 
worthy fisherman, who was present at its capture, that’one of over 
90 lbs. weight was left stranded by the receding tide at Prehen, 
about two miles. above Londonderry, some thirty years ago: the 
largest he has since seen was taken in a salmon net three miles 
higher up the river, and weighed 53 lbs. 

Siphonostoma typhle.-—Might not this be noted as very rare in 
Treland ? 

Nerophis equoreus.—I have seen one of 31 inches length. 

Nerophis ophidion.—The only two Irish examples: certainly 
known are those mentioned by Thompson, under the head of 
“ straight-nosed pipefish,” from the coasts of Down and Antrim. 
Those recorded as ‘“‘ snake pipefish ” belong to VV. equoreus. 

N. lumbriciformis.—I must demur to Thompson’s statement, 


OcitBy—On some Irish Fishes. 033 


that this species and S. acus are “by far the most common pipe- 
fish” on the Irish coast ; for, according to my experience, IV. equo- 
reus outnumbers the two together by two to one, at least. 

Tetrodon lagocephalus.—For “'Tranmore,” read “'Tramore.” 

Orthagoriscus mola is uncertain in its visits to the north coast. 
Occasionally it appears to be common, as in 1876; but from that 
date till 1879—when I left Portrush—I did not see a single one. 
During the summer of 1876 one over 5 ft. long was caught in the 
salmon nets. 

Acipenser sturio.—About a dozen are got annually in the 
salmon nets of the Foyle estuary. The largest which my informant 
(Mr. Wm. Donaghy, of Dunnalong) remembers to have seen 
measured 9 ft. 2in., and was sent by the Fishery Company to 
London for use at the Queen’s coronation dinner. 

Carcharias glaucus.— For “Nymph brand,” read “ Nymph 
bank ’”’—this is off the coast of Waterford. I am afraid that Mr. 
Blake Knox has overstated its abundance in Dublin Bay (see 
Zoologist, 1866, p. 509). 

Galeus vulgaris.—Locally “ famrie” on north coast. 

Alopias vulpes.—That this species is “ often very common in 
Dublin Bay,” as stated by Mr. Blake Knox, cannot but be 
erroneous. That no specimen has ever been captured there, and 
no competent icthyologist ever recorded it from so thoroughly well- 
known a locality, speaks for itself. 

Scylliwm canicula 1s commonly eaten by. the poorer classes 
about Portrush, and esteemed superior to the piked dog, which is 
also largely consumed. It is equally common in summer and 
winter, and feeds quite as much by day as by night. 

Acanthias vulgaris.—I can quite vouch for the boldness of this 
horrid fish; many a time I have amused myself, while my fisher- 
man was hauling the deep-sea lines, by gaffing the “ goboys”’ as 
they swam round the boat, in readiness to seize anything which 
might fall off the hook while coming up; and more than once I 
have seen the whole pack, perhaps as many as a score, start like 
hounds after a ling or cod which had managed to struggle clear of 
the hook. There is no doubt that the wound caused by the dorsal 
spines is excessively painful, and frequently suppurates; but per- 
haps the continual wetting with salt water may induce, or at least 


534 Scientific Proceedings, Royal Dublin Society. 


increase, the latter. Although they eat about a third of the hooked 
cod and ling, I never knew a conger to be touched. 

Torpedo nobiliana.—In his summary of the two species (p. 331), 
Dr. Day correctly mentions the difference in the comparative sizes 
of the dorsal fins in the two British species, but these are not 
shown at all in his figures; or, if anything, are more prominent in 
T. marmorata. 

Raia batis.—“‘ Caillach”’ on the north coast is, next to the 
thornback, the most abundant species about Portrush. By con- 
noiseurs in skate small “ caillachs”’ are considered almost. the equal 
of “thornies” for eating fresh ; while large examples are said to 
be infinitely the best for, if not the only ones worth, salting. I 
have taken a thornback of 74 lbs. weight from the stomach of one 
of these fishes. JI must exonerate the fishermen of the north coast 
from so grave a charge of laziness (see Day, vol. 11., p. 337) as that 
of cutting their lines in order to save themselves the trouble of un- 
hooking fish caught by the pectoral fin, which a slight cut of a 
knife would do; but I have known large examples thrown over- 
board, and sometimes even cut adrift, in order to lighten an open 
boat in a heavy winter sea. In my experience of the capture of — 
many hundred skates of all sorts, I never knew of a single example 
being caught by the pectoral fin. They will take greedily whelks 
and any kind of fish cut up as bait, and are sometimes quite a nui- 
sance on the deep-sea lines. 

Raia fullonica.—Only captured on the deep-sea ae in winter. 
It is not at all uncommon at Portrush, where it is locally known as 
the “ piper,” and is considered fair eating. The largest that I 
have caught measured 42 inches. ‘The teeth in a female example, 
examined March 29th, 1878, were as sharp-pointed as those in 
males captured on the same day, strong and slender in both. 

Raia clavata.x—Enormous numbers are taken in summer on 
Magilligan strand, both by trawl-boats and by lines baited with 
sand-eels or fresh herrings. They are shipped fresh to the Liverpool 
market. It is by far our most abundant species, and most prized 
as food. When in good condition and cooked in a similar manner, 
it can hardly be distinguished from dressed lobster. 

Raia maculata.—The “bengore skate” of Lough Foyle. Com- 
mon in winter, and found in deeper water, with a FOUBHEE) bed than 
the preceding ; considered worthless as food. 


Octrsy—On some Irish Fishes. 535 


Raia cirewlaris.—This species is not uncommon on the bank off 
Portrush, where it is taken on the winter cod-lines. I have notes 
of ten caught in my own boat between December, 1877, and October, 
1878, inclusive ; of these, seven were females. In the largest ex- 
ample—883 inches total length—the pectoral blotch was absent, — 
and, in its place, were eight white dusky-margined ocelli, placed in 
regularly corresponding pairs, on the opposite sides of the disk: 
this specimen weighed 133]bs. In the nine others, which corre- 
spond to the “sandy ray” of Couch, the blotches were present, and 
one of them measured 30 inches over all, and weighed nearly 7 lbs. 
There can be no doubt of their specific identity. I think it proba- 
ble that old individuals lose the blotch characteristic of the small 
examples. 

Trygon pastinaca.—It must be observed that no competent 
icthyologist—and we have had many good observers on all sides of 
our island of late years—speaks of having personally examined an 
Irish example. I would, therefore, reject it ix toto from our list, 
which is far too much filled up with species of whose occurrence 
and identification there is no sufficient proof. 

Myliobatis aquila should certainly be omitted for the same 
reasons. 

Petromyzon marinus. —Common in the Foyle; but invariably 
thrown away. 

Petromyzon fluviatilis—I know of no Irish rivers in which this 
species is found. 

Petromyzon branchialis.—Is found in streams and mill-races, 
lying on the southern water-shed of the Foyle. On one occasion . 
I got a lampern adhering to a cod taken in 20-fathom water at a 
considerable distance from the shore, which, when examined, 
proved undoubtedly to be this form, with undivided dorsals. 

Branchiostoma lanceolatun.—There is a mistake about my spe- 
cimens (mentioned on p. 366). ‘They certainly could not have 
belonged to this species, as the eyes were easily visible. I con- 
sidered mine to be much more likely a Leptocephalus. 

Schedophilus medusophagus.—¥or ‘‘ south coast” read ‘north 
coast,” and see ante, p. 019. 


[ Be 


LXXIV.—NOTE ON THE BLASTODERMIC VESICLE OF MAM- 
MALS. By ALFRED C. HADDON, M.A., M.RB.I.A., 
Professor of Zoology, Royal College of Science, Dublin. 


[Read, June 15, 1885.] 


Havine recently had occasion to refer to the development of 
mammals, it occurred to me that the significance of the so-called 
‘“blastopore of van Beneden” might be capable of elucidation. 
I therefore beg to offer the following note on the subject which 
may tend towards that. object. 

The following is a brief account of the segmentation of the 
rabbit’s ovum, as described by Ed. van Beneden (8, 4, 5) :— 

Within an hour or two after fertilization the ovum commences 
to segment ; the whole process of segmentation occupies from 
seventy to seventy-five hours, by which time the ova have just 
entered into the cavity of the uterus. 

The ovum divides into two nearly equal spheres; the larger is 
clearer and somewhat differently acted upon by reagents than the 
other. Van Beneden believes that this indicates a fundamental 
difference between the two celis; the larger cell representing, ac- 
cording to NM the “ectoderm,” and the smaller granular cell the 

“endoderm.” In Quain’s Elements of Anatomy, vel ii. (9th edi- 
tion, 1882), p. 744, they are spoken of as “upper” and “lower ” 
spheres respectively ; but in the description of the figures (figs. 
630-1) ‘ectomere”’ and “entomere,” Heape adopts the preferable 
plan of simply terming them and their derivatives “outer” and 
“inner ”’ spheres. 

Further segmentation into four and into eight spheres occurs 
in the usual manner. As is usually the case in holoblastic ova, 
the early-formed spheres are more or less spherical, and directly 
the third stage has been completed, the eight spheres lie in two 
tiers of four each in the ordinary manner; but very shortly one of 
the inner spheres passes into the interior of the mass, and the 
whole ovum regains its spherical contour. 

The fourth stage is marked by the segmentation of the outer 
cells only, the blastula now consisting of eight outer cells and four 


Happon—WNote on the Blastodermic Vesicle of Mammals. 587 


inner cells, the former being smaller than the latter, and tending 
to enclose them. 

The inner cells next divide, forming thirteen cells in all, and 
become markedly more opaque and granular; four of these cells 
pass into the interior of the mass. 

Further subdivision of the outer cells into sixteen cells causes 
them to extend still further over the inner cells. 

Segmentation continues in both sets of spheres till the tenth 
stage is arrived at, when the ovum consists of a solid central mass 
of thirty-two inner cells, entirely surrounded by sixty-four outer 
cells, except at one spot which van Beneden calls the “ blastopore.” 
The outer cells, however, soon entirely surround the inner. 

A cavity makes its appearance between the outer and the inner 
cells at the opposite pole of the ovum to that at which van Bene- 
den’s blastopore is situated. ‘This cavity rapidly enlarges, and the 
inner cells depend as a small mass from one pole of the ovum. 

About ninety-four hours after fertilization the ovum measured 
0:28mm., the diameter having tripled within the twenty-four hours 
since the ovum entered the uterus. It now consists of a thin walled 
vesicle, the blastodermic vesicle, the wall of which consists of a single 
layer of flattened cells, the products of the outer spheres. At one 
pole the inner cells form a flattened disc, the centre of which is two 
or three cells thick; the periphery is constituted of several rounded 
and more or less completely isolated cells. Later, these two por- 
tions of the inner mass become more distinguishable; the more co- 
herent central portion initiates the circular embryonic area (area 
pellucida), while the irregular outer zone is formed of a single 
layer of amoeboid cells, and gradually extends over the inner sur- 
face of the blastodermic vesicle, constituting the area opaca. 

During the fifth day the blastoderm consists of three layers, 
which van Beneden regards as the three embryonic layers. He 
tabulates them thus (p. 179) :— 

Stage V. (102 hours, or four days, six hours). 

Stage VI. (124 hours, or five days, four hours). 


Vv. VI. 
Ectoderm = Epiblast 
Mesoblast 

Endoderm = NM ceypopinat 


In other words, the diploblastic fifth stage is succeeded by a tri- 


5388 Scientifie Proceedings, Royal Dublin Society. 


ploblastic sixth stage. Although van Beneden makes this assertion, 
he does not prove it, and he gives no sections in support of his 
statement; so I take it we are at liberty to doubt this identifica- 
tion, as it lands us in so much difficulty. The upper layer is formed 
of the flattened outer cells of the blastodermic vesicle, and the lower 
layer, which is the true hypoblast, also consists of flattened cells, 
which are continuous outside the embryonic area with the zone of 
amceboid cells which is creeping round the blastodermic vesicle. 
Between these two layers is a third layer of rounded cells (Meso- 
blast of van Beneden), which is now recognized to be the embry- 
onic epiblast. 

Kolliker (12) regards the outer-layer as protective and belong- 
ing to the blastodermic vesicle, and the middle layer to be the true 
epiblast, and the deepest layer the hypoblast. He states that the 
outer layer disappears, the epiblast becomes columnar, and that the 
mesoblast develops later in connexion with the primitive streak. 

Rauber (16) also believes that the outer layer of the blastoderm 
of the rabbit (“‘ Deckschicht”’ or covering layer) early disappears, 
and that the epiblast is derived from the inner mass. 


Balfour and Heape (2, ii., p. 181), found on the sixth day that 
the embryonic area is throughout composed of— 

1. “A layer of flattened hypoblast cells. 

2. “A somewhat irregular layer of more columnar elements, 
in some places only a single row deep, and in other places two or 
more rows deep. 

3. “ Flat elements on the surface, which do not, however, form 
a continuous layer, and are intimately attached to the columnar 
cells below.” 

They believe they have in many instances been able to trace 
the flattened elements in the act of becoming columnar. Later, 
Heape (10) has afforded additional evidence for the rabbit, and 
has also shown it for the mole. 

Lieberkihn (14), from his researches on the dog and mole, also 
believes that the epiblast is formed from the superficial portion of 
the inner mass, together with the overlying outer layer, after the 
differentiation of the hypoblast from the former. 

Kupffer (13) finds that in the field-mouse (Arvicola) the cover- 
ing layer (Deckschicht), which is by-the-by attached to the uterine 


Happon—WNote on the Blastodermic Vesicle of Mammals. 539 


wall, is the seat of a rapid and early proliferation which pushes the 
embryonic area into the blastodermic vesicle. ‘The underlying em- 
bryonic area alone enters into the formation of the embryo itself, 
the epiblastic layer of which consists, apparently from the first, 
of a single layer of cells. 

In the earliest stage of the rat, figured by Fraser (8), six days, 
eight hours after impregnation, the blastodermic vesicle is elon- 
gated, and its cavity is greatly reduced by the projection of a solid 
mass of epiblast cells which projects into the cavity of the vesicle ; 
the inner aspect of these cells is lined by a single layer of hypo- 
blast. A well-marked layer of rounded cells (covering cells, Deck- 
enzellen) occurs at the placental pole of the blastodermic vesicle. 
In twenty-four hours the epiblast forms a single layer of colum- 
nar cells enclosing a central cavity, the neuramniotic + the false 
ammion cavity. ‘The Deckenzellen have by this time greatly in- 
creased in number. 

From the above it is quite clear that the outer cells of the fully 
segmented mammalian ovum correspond to the epiblast of the area 
opaca, or yolk-blastoderm, and that the epiblast of the embryo is 
formed from the upper portion of the inner mass, the lower portion 
giving rise to the hypoblast. There is still some discrepancy as to 
the fate of the outer or covering cells which grow over the “ blasto- 
pore” of van Beneden, and which form the flattened upper layer 
of the rabbit’s blastoderm. According to Balfour (rabbit), Heape 
(rabbit and mole), and Lieberkiihn (dog and mole), this layer 
enters into the formation of the embryonic epiblast; Kolliker and 
Rauber believe it disappears in the rabbit; Kupffer (Arvicola) and 
Fraser (rat and mouse) assert that the rounded cells of this layer 
become attached to the decidua, and do not form any portion of 
the embryo proper. 

A. consideration of these facts has led me to the view that we 
must recognize in the inner mass a germinal dise perfectly com- 
parable with that of the fowl during the later stages of segmenta- 
tion (cf. The Elements of Embryology, by Foster and Balfour, 1888, 
fig. 8, p. 22), which has sunk into the blastodermic vesicle owing to the 
absence of yolk. The outer layer corresponds to those epiblast cells 
which are gradually enclosing the yolk, the so-called blastopore of 
van Beneden indicating in an exaggerated manner the distinction 
between the embryonic and non-embryonie germinal layers. 


540 Scientific Proceedings, Royal Dublin Society. 


Haacke (9) and Caldwell have recently demonstrated that 
the previously known (ef. W. B. Spencer, “The Eggs of Mono- 
tremes,”’ Nature, xxxi., p. 132, December 11, 1884) but discredited 
fact that the Monotremata are oviparous, and that the eggs are per- 
fectly comparable with those of reptiles. Thus Balfour’s deduc- 
tion, from purely embryological data, that the mammalian ovum 
originally possessed a large quantity of food-yolk, has been tho- 
roughly verified. 

Van Beneden has shown that this ‘“blastopore”’ is a marked 
feature in the ovum of a rabbit. Balfour (2, fig. i844, p. 178) 
and Allen Thomson (in Quain’s Ana- 
tomy, ii., 1882, fig. 631a, p. 744) have 
reproduced the stage just before it is 
closed over, and thus do not show it at 
its greatest development. Van Beneden 
and Ch. Julin (6) figure a segmented 
ovum of the great horse-shoe bat in a 
very similar stage (woodcut, fig. 1), the 
chief differences being that in the for- 
mer the outer cells are quadrate and eer le teary iting 
not somewhat flattened ; the inner mass great howe: og ‘bet (after van 
entirely fills up the cavity of the blas- 
todermic vesicle, instead of there being a considerable cavity as 
in the bat. In the former, the cells of the inner mass are well 
defined, whereas in the latter ‘‘it is impossible to distinguish the 
limits of the cells;” and, lastly, “the break in the continuity of 
the ectoderm, occupied by several ‘ endodermic’ cells, appears to 
be homologous with the ‘blastopore’ of the rabbit; it is here of 
much greater extent and persists longer. In the rabbit it nearly 
always closes before the blastodermic cavity commences to form.” 

In the earliest euaee of the mole, figured by Heape (10), the size 
of this “‘ blastopore”’ and the general appearance of the ovum suffi- 
ciently resemble the last stage of the rabbit’s Moen men- 
tioned above. 

Dr. A. Fraser informs me he has not yet satisfied himself as to 
the presence of such a “ blastopore”’ in the rat or the mouse. 

The accompanying diagrams (figs. 2-5) may render this view 
more clear. Fig. 2 represents the ovum of a hypothetical primi- 
tive inammal (the monotreme’s ovum is doubtless very similar to 


Happon—Wote on the Blastodermic Vesicle of Mammals. 541 


this) in which the yolk is still present, and the yolk is partially 


Fig. 2. 
Diagramatic transverse section through the blastoderm and yolk of the ovum of a 
hypothetical primitive mammal. 4%. embryonic epiblast; ef’. non-embryonic 
epiblast, z.e. the epiblast of the area opaca; Ay. hypoblast; 7. yolk. : 


surrounded by the yolk blastoderm, the blastoderm itself consist- 
ing of an epiblastic layer and lower-layer cells. In fig. 3 the 


Sy Ss> 
LAAT TTT LSS 
a eS 


2 


SSSOERs Res 
SSas 


"4 
Fig. 3. Fig. 4. 

Diagramatic transverse sec- A later stage than fig. 3. The 

tion of a hypothetical mam- non-embryonic epiblast ef}. 

mal’s ovum, at a stage cor- has now grown over the em- 

responding to Fig.1. The bryonic area to form the 

yolk of the.primitive mam- covering cells. 

malian ovum is now lost. Lettering as above—y. s. yolk 

sac. 


yolk is supposed te have been lost, and owing to its absence the 
yolk blastoderm, i.e. outer cells, have completed the blastodermic 


eee 
PEL 
IOS a 


<s> 
LEAS 


Goo 


Fig. 5. 
Diagramatic section of a mammalian blastodermic vesicle, in which the primitive in- 
vagination of the blastoderm is rectified, and the covering cells have extended 
over the blastoderm. Lettering as before. 


vesicle, and the blastoderm has sunk within the vesicle. This prac- 


542 Scientific Proceedings, Royal Dublin Society. 


tically corresponds to the ovum of the bat figured above, fig. I. 
In fig. 4 the yolk blastoderm has grown over the embryonic area, 
forming the covering cells (Deckenzellen). Lastly, in fig. 5, the in- 
vagination of the embryonic area is rectified, and there is a diplo- 
blastic ovum, the covering cells (Deckenzellen) forming the spurious 
third layer which misled van Beneden. 

If the above interpretation be correct, it further follows that we 
have a very abbreviated segmentation occurring in the mammalian 
ovum. Accepting van Beneden’s very precise statements, the inner 
mass (germinal area) is derived from one of the two primary seg- 
mentation spheres, the blastodermic vesicle being derived from the 
other. In other words, the first cleavage furrow demarcates the 
embryo from the yolk-sac. 

Embryologists are now paying considerable attention to the 
orientation of the primitive segmentation spheres. 

Agassiz and Whitman (1) have quite recently given a very care- 
ful account of the segmentation of some pelagic eggs of certain 
Teleostei (Ctenolabrus, Pseudorhombus melanogaster, P. oblongus, 
and T'antoga), and they find that the first cleavage plane corre- 
sponds with the long axis of the future embryo. It is a well- 
known fact that the nuclear spindles of one cell-generation tend 
_ to arrange themselves at right angles to those of the preceding 
generation. ‘The primary spindle (archiamphiaster), during divi- 
sion to form a polar globule, almost invariably coincides with the 
axis of the ovum (¢.e. is radial); hence the first cleavage spindle 
usually assumes a position perpendicular to this axis (¢.e. 1s bilate- 
ral), and the corresponding cleavage falls in a meridian plane 
which coincides with the median vertical plane of the embryo... . 
“We would carry the generalization one step farther, and say it is 
highly probable that the first cleavage spindle invariably hes at right 
angles to the axis of the ovum throughout the metazoa, and that there- 
fore the first cleavage plane is always a meridian plane, at least in all 
cases where the first cleavage spindle is accompanied by cleavage” 
(p. 33). 

Concerning the mammalian ovum, they say: “ ‘The researches of 
van Beneden on the maturation, fecundation, and cleavage of the 
mammalian ovum, of which we have thus far received only a preli- 
minary account, leave it doubtful whether the first cleavage spindle 
is parallel with the axis of the ovum or at right angles to it. He 
calls attention to the pronounced polarity of the ovum, but expressly 


Happon—Wote on the Blastodermic Vesicle of Mammals. 548 


states that he has not yet obtained a complete history of the first 
cleavage spindle. The relation of the plane of first cleavage to the 
axis of the ovum is therefore undetermined. If the first cleavage 
divides the ectodermic from the entodermic pole, as supposed by 
van Beneden, it is most probably equatorial. If further researches 
prove that the cleavage begins with an equatorial groove, a very 
important exception to the general rule will be established. If, on 
the other hand, it turns out that the first cleavage is meridian, it 
_will be difficult to reconcile this fact with van Beneden’s opinion 
on the destination of the first two cleavage-spheres”’ (pp. 36-7). 

Remembering the great disturbance to normal segmentation, 
which must result first from an increase in the amount of food 
yolk, and secondly from its loss, it is not surprising that the 
segmentation of the mammalian ovum apparently forms an ex- 
ception to the general rule—an exception, moreover, which would 
but emphasise the rule. 

Hoffmann (11) states that he has observed in the ova of certain 
Teleosts (Scorpeena, Julis, &c.), the axis of the primary nuclear 
spindle (archiamphiaster) is identical with that of the ovum; and 
when two nuclei have been formed, beth le in this plane, the subse- 
quent cleavage results in the division of the egg into two very un- 
equal portions, an upper and smaller ‘ archiblast”’ (germinal disk), 
and a very much larger “ parablast”’ (yolk). ‘‘'The archiblast alone 
segments, its nucleus is the parent of all the cleavage nuclei; the 
parablast doos not segment, nuclear division only takes place within 
it ; it is altered into a multinucleated cell.” Agassiz and Whitman 
discuss Hoffmann’s conclusions so keenly that until further evidence 
is forthcoming we can only accept their view of Teleostean segmen- 
tation. 

Ryder (17, 18) supports Hoffman’s conclusions, but without 
giving a sufficiently precise account of his own observations on 
the point. 

There can be but little doubt that the first immigration of blas- 
topheres into the interior of the ovum (van Beneden’s stage 3) 
indicates the gastrula stage. It would further appear that this 
immigration was asymmetrical, much as there is an asymmetrical 
invagination of the hypoblast in telolecithal ova. 

Unfortunately, van Beneden’s is the only account we possess 
at the present time of the segmentation of the mammalian ovum. 

SCIEN. PROC., R.D.S.—VOL. IV. PT. IX. 2Z 


544 Scientific Proceedings, Royal Dublin Society. 


When this process has been described in forms other than the 
rabbit, we shall be in a position to see how far the development 
of this rodent agrees with or differs from that of other mammals. 

The extension of cells of the blastodermic vesicle over the em- 
bryonic area is probably to be accounted for in most cases by the 
sinking of the latter into the cavity of the former. I have pre- 
viously alluded to the various views which are held concerning 
their fate. These Deckenzellen are really a portion of the blasto- 
dermic vesicle, that is, of the yolk-sac, and they form the first adhe- 
sion between the ovum and the parent. ¢ 

It has recently been demonstrated that in marsupials the yolk- 
sac forms (at all events at first) the only adhesive surface of the 
embryo. Osborn (15) states that in the Virginian opossum 
(Didelphys virginiana), and in other unnamed forms from Australia, 


Fig. 6. | Fig. 7. 


Diagram of the foetal membranes of the Virgi- Diagram of the foetal membranes of the 
nian opossum (D. wzrg¢ntana) with two villi native bear (Phasoolarctos cinercus), 
greatly enlarged. The processes of the cells also showing the amceboid processes 
of the villi have been drawn too large and of the (epiblastic) cells of the subzonal 
too numerous; they doubtless correspond to membrane. After Caldwell. 


the pseudopodia described by Caldwell.— 
After Osborn, slightly modified. 


al. allantois; am. amnion; amb. amoeboid processes of subzonal membrane; hy. hypoblast of 
yolk-sac; s. ¢. sinus terminalis; s. z.. subzonal membrane; y.s. yolk-sac. The black line 
in both figures indicates the extension of the vascular system. 


that portion of the subzonal membrane which is in contact with 
the yolk-sac, chorion of the yolk-sac, gives rise to very simple vas- 
cular villi, by means of which the embryo is slightly attached to the 
uterine wall (fig.6). Caldwell (7) found that in Phascolarctos cinereus 


Havpox—Wote on the Blastodermic Vesicle of Mammals. 5465 


and Halmaturus ruficollis the cells of the subzonal membrane over- 
lying the yolk-sac outside the sinus terminalis become amceboid, 
and throw out pseudopodia-like processes which fit in between the 
cells of the uterine epithelium and serve to attach the blastodermic 
vesicle to the uterus (fig. 7). This attachment is entirely non-vas- 
cular, and is the sole means by which the vesicle is attached to the 
uterus, no villi being formed. 

From the nature of the case no adhesion occurs between the 
embryo and the parent in the Prototheria. In the Metatheria a 
very shght connexion does occur, but in this the yolk-sac alone 
takes part. As the latter was the sole nutritive organ of the 
earlier mammals, it would but slowly part with this function. 
Ryder (19) has suggested that the degeneracy of the yolk of the 
mammalian ovum may be due to the development of the so-called 
uterine milk from the uterine glands, and to have atrophied in 
consequence of the perfectly parastic connexion subsisting tempo- 
rarily between the maternal organism and the embryo, as was sup- 
posed by Balfour. At this stage of evolution the allantois was 
purely respiratory, as it is in the Sauropsida, and the yolk-sac’ 
(blastodermic vesicle) was becoming less nutritive in function. 

In the Eutheria the placenta is formed by fusion of the allan- 
tois alone with the subzonal membrane, the yolk-sac becoming in- 
creasingly reduced. In the rabbit the yolk-sac spreads over a large 
portion of the subzonal membrane, leaving but a small area for the 
necessarily discoidal placenta; and, save for the non-adherence of 
the yolk-sac, and for the production of an allantoic placenta, a 
diagram of a rabbit’s ovum in an advanced stage of pregnancy 
(cf. Balfour, Joc. cit. 11., fig. 148, p. 200), corresponds closely with 
that of Caldwell’s Marsupials (fig. 7). In higher mammals the 
yolk-sae has a diminished and the allantois an increasec extension. 

Bearing the above in mind, it is very interesting to find that 
the first attachment of the embryo to the parent in some rodents 
is by the covering cells (Deckenzellen) which are later replaced by 
the villi of the allantoic placenta. It may be that this has relation 
merely to special cases; but it is probable that when our knowledge 
is more complete in such details it will be found that in many 
Eutheria there is a temporary adhesion of the walls of the blas- 
todermie vesicle to the uterus which is subsequently supplanted by 
the allantoic villi. 


546 


iO; 


3. 


5 Lhe 


Scientific Proceedings, Royal Dublin Society. 


LIST OF REFERENCES. 


. Agassiz and C. O. Wurrman :— 


‘“On the Development of some Pelagic Fish 

-Kegs.’”’-—Proc. Am. Acad. of Arts and Sci., 
vol. xx. 1884. 

M. Batrour, .... A Treatise of Comparative Embryology, vol. ii. 
London: 1881. 

vaN BENEDEN,. . ‘‘ La Maturation de l’Oeuf, la Fécondation et 
les premieres Phases du Développement 
Embryonnaire des Mammiféres.”’— bull. de 
V Acad. Roy. des Sci. de Belgique. 1875. 

ee “ Journ. de Zoologie., vol. v, 1876. 

SA ae ~ Formation des Feuillets chez le Lapin.’’— 
Arch. de Biologie, vol. i. 1880. 


. VAN BENEDEN and Cx. JuLin :-— 


‘Observations sur la Maturation, la Féconda- 
tion et la Segmentation de Oeuf chez les 
Cheiroptéres.—Arch. de Biologie, vol. 1., 
p. 551. 1880. 


. CanpwELL,....‘‘On the Arrangement of the Embryonic 


Membranes in Marsupial Animals.” — Quart. 
Journ. of Mic. Sci., n. s., vol. xxiv. 1884. 


ERASER AIT. Vi). ‘‘On the Inversion of the Blastodermic Layers 


in the Rat and Mouse.’—Proc. Roy. Soc., 
vol. xxxiv. 1883. 


HN VELA Gt. cuca. ‘‘Meine Entdecken des Hierlegens der Kch- 


idne.’’—Zoolog. Anzeiger, vol. vil., p. 647. 
1884. 


W. Heapz,...... “The Development of the Mole (Talpa euro- 


pea).”—Quart. Journ. of Mic. Science, n.s., 
Vol. xxi. © 1883 


11. C. K. Horrmann, . . ‘‘ Zur Ontogenie der Knochenfische.”’ Amster- 


dam, 1881, and Vorlaufige Mittheilung zur, 
&¢.—Zoolog. Anzeiger, vol. iii., p. 632. 1880. 


12. A. Konnmer,..... ‘Die Entwicklung der Keimblatter des Kan- 


inchens.’’—Festschrift zur Feier des drei- 
hundertjihrigen Bestehens der J. Max. 
Univ. zu Wirzburg. Leipzig: 1882. 


Happon-—Note on the Blastodermic Vesicle of Mammals. 547 


18. C. Kurrrer,...... ‘‘ Das Hivon Arvicola arvalis und die vermein- 
bliche Umkehr der Keimblatter an demsel- 
ben.”’—Sitzungsb. der kK. B. Akad. d. Wiss, 
zu Miinchen. 1882. 

14. N. Limperxtun, .. . ‘‘ Ueber die Keimblitter der Siugethiere.”’— 
Zu der Finfzigjahrigen doctorjubelfeier d. 
Herrn H. Nasse. Marburg: 1879. 

15. H. F. Osporn, ... . ‘‘ Observations upon the Foetal Membranes of 
Opossum and other Marsupials.”—Quart. 
Journ. of Mic. Sct., n. s., vol. xxill. 1883. 

16. A. Rauber, ...... ‘“Ueber die erste Entwicklung des Kanin- 
chens.’’—Sitzungsb. der Naturforsch. Ges- 
ellsch. z. Leipzig: 1875. 

V7. Ji A RYDER, fst ‘A Contribution to the Kmbryography of 
Osseous Fishes.’—U. 8S. Fish. Commiss. 
Reports for 1882, p. 455. 1884. 


18. S a ‘The Law of Nuclear Displacement, and its 
Significance in EHEmbryology.” — Science, 
WOlle Map JO PAB GIS 

19. 3 5 ‘‘On the position of the Yolk-blastopore, as 


determined by the size of the Vitellus.’’— 
American Naturalist, p. 411. 1885. 


END OF VOL. IV. NEW SERIES. 


IPINCOKC SARS 


DUBS SOC. N.S: VOL DV: 


PLATE 


PROC. R. DUB. SOC. N.S. VOL. IV. 


Z Wy = 


“JSP OReilly, del. 


MW vi\} \ Tip sa beet \\ 


PLATE II. 


Seale atout F707, 


Forster & C° Lith Dublin. 


Crystats. 


2 Glesarilt (ME 


Plate III. 


Proce. R.D.S., N.S., Vol. 4 


7 
: 
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Sectional Elevation thro a. 


eT. 


un, 


borster & CT, 


KE, 


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One half 


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Proc. R,D.S., N.S., Vol. 4 Plate1V.. 


Proc. R.D.S., N.S., Vol. 4. Plate V. 


H- St. J. B., del. FoRSTER & Co,, Lith., DUBLIN. 


wa) Lape! 
rho posh ea NRT a 


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Proc. R.D.S., N.S., Vol. 4. Plate VI. 


H, St. J. B., del. FORSTER & Co., Lith. DUBLIN, 


Aut 
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Proc. R.D.S., N.S., Vol. 4. Plate VIII 


fa er ner ET a 


H. St. J. B., del. Forsrer & Co., Lith., DUBLIN. 


Proc. R.D.S., N.S., Vol. 4. Plate IX. 


FORSTER & Co., Lith., DUBLIN, 


Ry 


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nia 


Plate X. 


Proc. R.D.S., N.S., Vol. 4, 


a0. Pe: 


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ForsTER & Co., Lith,, DUBLIN 


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Proc. R.D.S., N.S., Vol. 4, : Plate XI. 


storia es 


A, C, Haddon, Del. ForstErR & CoQ,, Lith., DUBLIN 


K 


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Proc. R:D:S., N:S., Vol. 4. Plate XII. 


Forstk: & Co., Photo.-Lith,, DUBLIN 


Proc. R.D.S., N.S., Vol. 4. Plate XIII. 


Forster & Cc., Photo.-Lith., DUBLIN 


phe kA 
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Plate XIV. 


Proc. R.D.S., N.S., Vol. 4. 


Fo | 
Jarrow Channel and the One foot Coal (Queen's Co. portion trom Mr Meadows Working Section | 


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Plate XV 


Proc. R.D.S., N.S., Vol. 4. 


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Proc. IQnIDEISe INeSas Vol. 4 J nf se Plate XVIL 


9 


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Proc. R.D.S., N.S., Vol. 4. ; Plate XVIII. 


ACH ad. nat. del. ForRSTER & Co., Lith., DUBLIN 


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Plate XIX, 


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STAMEN HAITRS. 


Plate XX. 


Proc. R.D.S. N.S. Vol. 4. 


West Newman & C2? lth. 


SoM INE ISURIUISC'S) - 


Proc, IRD) Sag N. Sho Vol. 4. Plate XXI. 


T. H. Thomas, del. et lith. Forster & Co., Imp., DUBLIN 


——— 


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