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Ast Eee ve gy 1a ena aN ea wa Pest 0 Py Media Uw ‘ weeny \ ‘ SRE ci TY et ‘ ve hea geet 0 +¥ ' wh ve gh a ee wees few wise Reiss 7 MT Se bh | wee Ll hd Wathetad gieeage iden * me rn ai ae st “ rah ’ ‘ OCR Cees cr ry , a4 PLATA IPRS POR MER a Rare 4, tet dan ay § , Ces rh Hoy alae) Thea} ore a) We Y Ve aw ately VVireaid bey oe Fv Mises Mts bash alye taeda eh yet ehietob PI iH Gt Tevon d tein ae Pa ony ayicera hres bpauhebausny vopsacray ya Hes Sete bran dds eee ied ets nssags peal ape ene eae ry grate Gas, na ws he Welatint MY Tis by Sr Lae ' Py Abed gh Gabre wea ty Rt brewtipreeage. ‘ yes Peery Hy Mew 44 top| 4 ‘yt vee ser | on seta atan ths setae tor Mave ait OUrTs Weaics Peat ied Vie ' Wovity 1 hig Ooty wrored ‘ Aisin yy WAV te Ae Dr anderata, ey 40 dy hited ale DONOR es Pe PO er ee WAL Ole dy, eka ty Hepes bin tena 910 See we ee o8 Pte eh Oabela yet ores WO yy tes Vana ts § W Mine SMe en Nei tee ait ah iitetion she Abie vbr wher, OR Ce ai ena ou 0 yy ipa OP Ay vy * 7 Lae SO ed pam bbe VS CO eee er rao i ete Pt a tat ty Tela leatitan ge bah Aas ak De ee ea eT ree v * Mi Te bibease Miho miy oto dee pene POA AnASLRA OURO RA COEATIC UTM AN ER ATL RO HEY IEC SOEs Sean Aol PRE ae nd Rei es A Bch Reka Ve BOGOR To Or Mrapbee bees Wort Pee is See BU Ce LURE EY ae Ware hed ‘ i] rated Pree rs ee a va yo ie Hyer eos OLE ed yal SECS) UMRAO UA aCe Ea Bri On were Bibra) TUNG re Lg ere aC Trony RN Vases hey at ce wiped, LAL CRO ret WEA ae baat yee a Ste en ed be ber eraet ee ee Pe pha viye wah hee CO rT i POINTES VRO UO eye een nee ey i ee Meet gine MVE vine» Ae Orb tede oak - wa VST EPR ape iny Pe ee es bee oye Wales vb ML TE Jerre hve rh eoce, chp, Su.tila wae sue yg wong rigeh vr et ath ‘ wi * Ste ee ae 34 )) bs Bite f ie HH) ney UR Fe yen) 3% Skt ey Tay Wey At ifs eee aes) Deere at How pee le Wt Gt wig wae : Re Bilyarotdedidan den a dlsbetad de bd, ta Pa , HAT War ) ue deutacges-std Salat odenkd a4 Hone eae bys hedetiae b wide Vga eat 5 a ‘a f ehiiue 44 Lee dae te aera lb y LR eo duo ahh ops Pee is rere Pn earner are maaan CBC wan SG foe cic ae dept tenth yhar abe nude tal Ke Pad oy be bagihe bed ry aes “ ye iV fe tcgiegee teat tse i iF Pyity ah Hien ivi spied etre Si gaeasiae nity Ie! ros ata se oh :! sete: om Eh are iadaes Bay » ane olathe’ Pan cece . oe SORE a Pe arr y Pare wid Cpe Tee petal Bate “ soe TE Ee ei a pda a eb ae ed ae Rea ORE Cin a wheat ere ay "a rene Mapes . hei \ Sts 4 Danae ren rvs a Hotbard\ he es Wid rf me ais pe! uae aie se en ate uf th pe a it on ; Are hr tne Fn ee lpearen: eee ’ DUA atte fed Wadd du ashen rice a . ‘ ret te Oe er Wr | eae rae © al he ee > BOReron tres t 1 see a See ee te ay fa ae ia’ shen Ai i stig a . batve ete ly RN RIN isang ay ity svat A alee ares 0 ‘ > ’ ‘e stone A Ea Wa Sah Wa ate A oem pets he aw ‘ bh oe od “ ioe a LA “ ' A be Pe are ar gre ere i We Tae hh by bee baetes. beth anni “ ay ‘ t : ‘ ‘ Tht. ge leew ial 4 ead bree aii sald isons ' . ‘ + ‘ . 4a hopes we she tity Shey ‘ “ ‘ . Fy yeu Wire) a UH Pa ‘ ibe ‘a wend wliw a} vag 1 seedteana a ‘ - . eink Sat hg ws cave devia het g Lie ti oe Cob etreas totes ve ‘ et ED het a) eal aby me ay baa ien a % THE SCIENTIFIC PROCEEDINGS OF THE ROYAL DUBLIN SOCIETY. Tue Society desires tt to be understood that they are not answerable for any opinion, representation of facts, or train of reasoning, that may appear in this Volume of their Proceedings. The Authors of the several Memorrs are alone responsible for their contents. THE SCIENTIFIC PROCKEDINGS OF THE ROYAL DUBLIN SOCIETY. Hew Series. V Onn Ui 2 lie 218 ASA DUBLIN: PUBLISHED BY THE ROYAL DUBLIN SOCIETY. PRINTED BY ALEX. THOM & CO., 87, 88, & 89, ABBEY-STREET, THE QUEEN’S PRINTING OFFICE. FOR HER MAJESTY’S STATIONERY OFFICE. 1883. Ob. Ti> inion T Or. ot rhe COND Folie Uw TORS TO VOLUME THREE, WITH REFERENCES TO THE SEVERAL ARTICLES CONTRIBUTED BY EACH. ARGALL, PHILIP. Notes on the Tertiary Iron Ore Measures, Glenariff Valley, County Antrim. Plates 16, 17, 18, and 19, . ARGALL, Puinip, and KINAHAN, GERRARD A. Notes on the Recovery of Copper from its Solution in Mine Drainage with Special Reference to the Wicklow Mines. Plates 22 and 23, Bau, V., M.A., F.G.S. On the Identification of certain Localities mentioned in my Paper on the Diamonds of India, Catalogue of the Examples of Meteoric Falls in the Museums of Dublin, . Burton, Cuas. E., F.R.A.S., and Gruss, Howarp, F.R.A.S. On a New Form of Ghost Micrometer for use with Astro- nomical Telescopes. Plates 1, 2, 3, and 4, Cameron, Cartes A., M.D., Fellow and Professor of Chemistry, Royal College of Surgeons, Ireland. On the Composition of the Milk of Forty-two Cows, Ciosz, Rev. Maxwett H., M.A. On the Definition of Force as the Cause of Motion, with some of the Inconveniences connected therewith, PAGE 151 336 Vi List of the Contributors. FITZGERALD, GEORGE Francis, Fellow of Trinity College, Dublin, and Erasmus Smith’s Professor of Natural and Experimental Philosophy in the University of Dublin. Note on Mr. J. J. Thomson’s Investigation of the Hlectro- Magnetic Action of a Moving Electritied Sphere, On Comets’ Tails, ; : : 3 - FREKE, Percy Evans. North-American Birds crossing the Atlantic, . : é On Birds observed in Amelia County, Virginia, . - Gruss, Howarp. (See Burton, CHARLES E.) Harpman, Epwarp T., F.C.S8. On a Travertine from Ballisodare, near Sligo, containing a considerable amount of Strontium, . Harpman, Epwarp T., F.C.S., and Professor Hutt, LL.D., F.R.S. On the Metamorphic Rocks of Cos. Sligo and Leitrim, and the enclosed Minerals, with Analysis of Serpentine, and Microscopical Notes on the Serpentine, &c. Plate 33, Hartiey, W. N., F.R.S.E., &c., Professor of Chemistry, Royal College of Science, Dublin. Description of the Instruments and Processes employed in Photographing Ultra-Violet Spectra. Plates 12, 13, 14, and 15, Huveeins, Wiiiram, D.C.L., F.B.S., &c. Photographic Spectrum of Comet, . Huu, Epwarp, LL.D., F.R.S8., Director of the Geological Survey of Ireland. On the Geological Structure of the Northern Highlands of Scotland ; being Notes of a Recent Tour. Plates, 9, 10, and 11, On the recent remarkable Subsidences of the Ground in the Salt Districts of Cheshire, (See also HarpMAN, EDWARD). PAGE 250 344 22 61 357 93 150 34 133 List of the Contributors. Hut, Epwarp, B.A. On the Origin and probable Structure of the Domite Mountains of Central France, KINAHAN, GERRARD A. “Black Sand” in the Drift North of Greystones, Co. Wicklow, On the Mode of Occurrence and Winning of Gold in Treland. Plates 20 and 21, Some Notes on the Geology of Bray Head, with a Geo- logical Map and Sections. Plates 24, 25, 26, (See also ARGALL, Putuip). Kinanan, G. H., M.R.LA., &e., President Royal Geological Society, Ireland. Cork Rocks, On the thicknesses of the Irish Bedded Rocks. Plates 7 and 8, Anniversary address to the Royal Geological Society of Ireland, Glacial Moraines on Mount Leinster, Counties Wexford and Carlow. Plates 27, 28, and 29, . Paleozoic Rocks of Galway and elsewhere in Ireland, said to be Laurentians. Plates 30, 31, and 32, M‘Arpte, Davip. Notes on some New or Rare Irish Hepatice. Plates 5 and 6, Ociupy, J. Douatas. A Catalogue of Birds obtained in Navarro County, Texas, Rzynoips, J. Emerson, M.D., F.R.S., Professor of Chemistr University of Dublin. 5) On a New Analysis of the Lucan Sulphur Spa, Vil PAGE 145 165 263 329 47 108 109 334 347 17 169 vill Lust of the Contributors. SmitH, W. Preliminary Note on the Manufacture of Paper from Molinia coerulea, Concluding Note on the Manufacture of Paper from Molinia cceerulea, Stoney, G. Jounstons, D.Sc., F.R.S. On the Physical Units of Nature, . On Musical Shorthand, Ticuporne, C. R., LL.D., F.C.S., &e. On a New Form of Apparatus for Estimating Ammonia in Potable Waters, TRAILL, GEORGE WILLIAM. Alphabetical List of the Parasitical Algze of the Frith of Forth, PAGE 14 141 51 371 255 286 | (THE SCIENTIFIC PROCEEDINGS ROYAL DUBLIN SOCIETY. Vou. III. (New Ssrizs)) JANUARY, 1881. Pari I. CONTENTS. i Page I. On a New Form of Ghost Micrometer for use with Astro- i nomical Telescopes. By Cuas. E. Burro, F.R.A.S., and Howarp Gruss, F.R.A.S. Plates 1,2,3,and4, . Li II. On a Travertine from Ballisodare, near Sligo, Nene ania! a considerable amount of Strontium. By Epwarp T. Gace: F.CS., : 5 : 12 III. Poissy Note on the ae of Pape from Molinia cerulea. By W.Smirn, . 5 14 IV. Notes on some New or Rare Irish Hepatic by Davi M‘Arpre, Plates 5 and 6, 17 -V. North-American Birds ne the eae By ee Evans FRexe, : 22 “at "0, oe National Mi Muse’. DUBLIN: | PUBLISHED BY THE ROYAL DUBLIN SOCIETY. PRINTED BY ALEX. THOM & CO., 87, 88, & 89, ABBEY-STREET, THE QUEEN'S PRINTING OFFICE. - FOR HER MAJESTY’S STATIONERY OFFICE. 1881, Roval MBublin Society. FOUNDED, A.D. 1731. IN CORPORATED, 1749. Evening Scientific Meetings. The Evening Scientific Meetings of the Society and of the associated bodies (the Royal Geological Society of Ireland and the Dublin Scientific Club) are held in Leinster House on the third Monday in each month during the Session. The hour of meeting is 8 o’clock, p.m. The business is conducted in the undermentioned sections. Section I.—PuysicaL AND EXPERIMENTAL SCIENCES. Secretary to the Section, R. J. Moss, F.c.s. Section II.—Narurat Screnozs (including Geology and Physical Geography). Secretary to the Section, R. M‘Nap, m.v. Section I{].—Scrence Appuiep To THE Userun Arts AND INDUSTRIES, Secretary to the Section, Howard GRUBB, M.E., 7.C.D. Authors desiring to read papers before any of the sections of the Society are requested to forward their communications to the Registrar of the Royal Dublin Society (Mr. R. J. Moss), or to one of the Sectional Secretaries, atleast ten days prior to each evening meeting, as no paper - can be set down for reading until examined and approved by the Science Committee. The copyright of all papers read becomes the property of the Society, and such as are considered suitable for the purpose will be printed with the least possible delay. Authors are requested to hand in their MS. in a complete form and ready for transmission to the printer. THE SCIENTIFIC PROCKEDINGS OF THE ROYAL DUBLIN SOCIETY. I.—ON A NEW FORM OF GHOST MICROMETER FOR USE WITH ASTRONOMICAL TELESCOPES, sy CHAS. E. BUR- TON, F.na.s.. AND HOWARD GRUBB, rF.r.a.s. Puatzs 1, 2, 3, AND 4, [Read, November 15th, 1880.] BEFORE describing the special and novel form of micrometer we have to introduce to your notice this evening it may be well to mention very briefly the various existing forms which this in- strument usually assumes, and note the special points in which it fails to fulfil its requirements with as much satisfaction as desired. The ordinary micrometer in general use consists essentially of a metallic box attached to the draw-tube of the telescope, in which are one or two frames or forked-shaped pieces sliding in carefully- planed grooves, actuated by a fine screw and micrometer head, and carrying spider’s webs or other very fine lines. These lines are so placed as to be exactly in the focal plane of the objective. When, therefore, the eye-piece is focussed on any image formed by the objective of the telescope it is also in focus for the wires or webs of the micrometer. According as the micrometer has one or two movable wire-frames and screws it is termed a unifi- lar or bifilar. In order to see these fine lines at night it is almost always necessary to illuminate them insome way. There are two distinct methods of doing this, viz. :— Ist. By throwing a little false light into the field, in which Scren. Proc., R.D.S. Vou. m1., Pr. 1 B 2 Scientific Proceedings, Royal Dublin Society. ease the lines appear black on a faintly illuminated ground, this is called the Bright Field Iumination. 2nd. By throwing light on the wires in such a direction that none of the beam can by possibility enter the eye-piece, in which case the lines appear luminous on a dark ground. ‘This is called the dark field or the Bright Line Illumination. The first, which can be used for all stars but those whose visibility is so slight as to be interfered with by the necessary amount of false light required to render the webs visible is more specially suited for faint stars and nebulee, but can be used for any class of object. The optical arrangements by which the Bright Field Illumina- tion is obtained are too obvious to require detailed description. Sometimes a small, diagonal mirror is used, placed centrally in the tube and illuminated by a lamp hung in gimbals so as to pre- serve its verticality ; sometimes an elliptical diagonal mirror, with an elliptical hole sufficiently large to admit the pencil of light from the objective. But this is a matter of extreme simpli- city, requiring no special care further than that the illumination should be as far as possible symmetrical and not one-sided, a condition easy to fulfil in this case. The optical arrangements, however, for producing the “ bright light” in “dark field” illumination are not so simple, and as this is a matter in which no thoroughly satisfactory result has yet been attained, we purpose describing the various arrange- ments at present in use somewhat more particularly. One of the most common arrangements in use is to have four lamps attached to the micrometer-box, directing beams of light at an angle of about 45° on the wires. This plan has several disadvan- tages. The angle of 45° is about the largest that can well be used, and this is not sufficiently great to prevent some stray light from impinging on the field lens of the eye-piece, and though it does not actually enter the eye as a beam of light, it renders the field lens slightly luminous and destroys the blackness of the field which is essential to this class of illumination. Another disadvantage is the extreme inconvenience of having lamps attached to a micrometer close to the observer’s eye. These lamps cannot well be hung in universal joints, consequently every time the telescope is turned, or micrometer revolved into different positions, the lamps must be re-arranged, and if this be not done On a New Form of Ghost Micrometer. 3 constantly and carefully, the lamps, not being vertical, allow the oil to escape over the micrometer and person of the observer ina highly objectionable manner. So great is this nuisance that almost invariably observers try and work with one lamp; but this is essentially bad, giving a one-sided illumination to the wires, and thereby causing serious errors of estimation. The next plan we would notice is that of surrounding the system of wires by a thin, translucent substance such as a very thin tube of ivory, and rendering this luminous by light thrown in any direction. This plan answers tolerably well for a faint illu- mination ; but it is difficult to obtain sufficient brilliancy for any save faint objects, andif any considerable brilliancy is obtained it is almost impossible to prevent the field lens of the eye-piece becoming luminous and destroying the blackness of the field. As before stated, however, it can be made to answer for faint objects, and this plan has occasionally been used by one of the authors of this paper (Mr. Grubb), when other plans were not conveniently adaptable, as in the case of the Dunsink Refractor. A third plan is that for which arrangements have been made in the Vienna Telescope, but which, so far as it goes, has frequently been used before (see Plate 1, fig. 1). Four prisms or reflectors are placed in the telescope tube opposite the Dec. axis, which prisms direct the light down through four tubes placed in the interior of the main telescope tube. In the diagram (Plate 1, fig. 1), are two of these four prisms (the other two could not be shown with convenience). These four beams of light are then received on four small reflectors, two of which are shown in diagram. (r.r.) These reflectors surround the wire plate, and the light reflected from these mirrors passes across the wires at such a considerable angle as prevents any danger of the field lens being illuminated or the blackness of the field injured. A fourth plan is shown in Plate 1, figure 2, and is that adopted generally by one of the authors (Mr. Grubb) for his smaller in- struments. A prism, P, on outside of telescope tube receives light from a swinging lamp and reflects it down through a small tube attached to outside of main telescope tube, where it is thrown ona reflector, R. This reflector, R, is carried on the end of a T tube which is capable of revolution round the tube which carries the micro- Scien. Proc., R.D.S. Vou. r1., Pr. 1. Bee 4 Scientific Proceedings, Royal Dublin Society. meter. The tube which carries the micrometer is cut up with slots, so that it forms a “cage ’’ into which the beam of light can enter at any part of its periphery, excepting only for the slight obstruction of the bars of the cage. Inside this cage is another piece of tube carrying a diagonal reflector, m, m, with an elliptical hole large enough to allow the whole pencil of rays for objective to pass. By a simple mechanical arrangement the inside tube carrying the diagonal reflector, m, m, and the outside tube carry- ing the reflector, R,are made to revolve simultaneously by the action of one pinion head. Thus, the reflector, R, and the reflector, m, m, can always be kept in such a position as to receive the light from the prism, P, which is thus reflected from R to m, m, and from m, m, to the four reflectors, r, r, surrounding the wire frame, as in Plate 1, figure 2. A fifth plan is shown, Plate IL., figure 3, as used by Mr. Grubb for some of his larger instruments. In this plan the lamp is hung at end of Dec. axis, and sends a beam through that axis. At a certain point of that axis is placed a low power condensing lens, b, having a small opaque disc, o, attached to its centre. In the tele- scope tube opposite Dec. axis is fixed a prism, R, ground on one of its faces, concave, and having a convex lens cemented on to it thus forming an achromatic lens as well as a reflector. This reflector directs the rays in a diagonal direction down to the draw tube of the telescope, and when the curves of this prism and lens are properly proportioned it forms an image of the con- denser, b, and its opaque spot, 0, on the upper end of the draw tube, P P. The image is, therefore, of the form of a ring of light. At P P is placed a portion of an excentric lens, with a hole in the middle to allow the cone of rays from objective to pass. This lens serves a double purpose. It alters the direction of the beam so that it may travel down between two concentric tubes to the little prisms, p p, round the wires, and it also condenses the beam so that none need be lost, but all be caught by those small prisms, pp. From these prisms, p p, the light is sent across the wires as in the former cases. But few objections can be urged against the last three systems here described, except that they are all, more or less, difficult to diss, 1:12:05: wa3a adjusted, and, at the best, only afford - lumination for the fainter class of objects. On a New Form of Ghost Micrometer. 5 The attention of one of the authors of this paper (Mr. Grubb) was called to the subject lately, partly by the necessity of devising some special instruments for special work, but more particularly by a letter from Mr. S. W. Burnham, of Chicago, the well-known and successful observer of double stars, At the same time the attention of the other author (Mr. Burton) was called to the same subject by perusal of Prof. Kaiser’s paper, referred to further on,and on mentioning the special points of the matter to Mr. Grubb, Mr. Grubb was enabled to place in Mr. Burton’s hands a model of a micrometer, which he had devised to fulfil some of Mr. Burnham’s conditions, made without special reference to the points raised in Prof. Kaiser’s paper, but which did, nevertheless, meet them. On trial of this model micrometer Mr. Burton found it to work admirably, and since then the two authors, working together, have so far perfected the instrument which you see, bringing it into a convenient and workable form. The following short notice, which formed part of a paper read at a recent meeting of the Royal Astronomical Society, will help to convey an idea of the special point of the matter. It is well known that the ordinary wire micrometer is unsuit- able for the direct measurement of two classes of objects, namely, planetary discs and double stars near the limit of separability for the object glass employed. The difficulties attendant on its use in the cases above mentioned are briefly these—(a) (1.) on bringing a material line in contact with the image of a luminous object of sensible magnitude, diffracted light appears on the side of the wire furthest from the image to be measured; and (2nd), if a wire be placed on the image of a star, that image becomes elongated in a direction perpendicular to the wire: defect (1) rendersit extremely difficult to ascertain when a micrometer wire is accurately in contact with the limb of a planet—(b) by reason of the interval between components of extremely close doubles becoming filled with light when the wires are placed on the components, it is impossible to obtain direct measures of such objects with the required certainty. The difficulties above indicated have been treated very com- pletely by Professor Kaiser,in volume 3 of the Leyden Observations, pp. 104-5, where he refers with approval to a proposal by Lamont 6 Scientific Proceedings, Royal Dublin Socrety. (Jahrbuch der K.S. bei Miinchen; seite 187) to employ ghost lines for such measurements, and by the Rev. W. R. Dawes, in Mem. Royal Astronomical Society, vol. 35, pp. 153 and 161. The suggestions of Professor Kaiser seem never to have been carried into effect. In the proceedings of the Vienna Academy of Sciences for 1856, vol. XX., page 253, H. Karl v. Littrow describes a mode of forming a “ghost” of a system of lines, applicable and actually applied to a meridional telescope. In this instrument the “ghost” lines are in- terrupted at or near their centres, by the interposition of an opaque bar, and the star is caused to traverse the series of blank spaces thus formed. It does not appear, however, that any attempt was made to adapt this to a position micrometer of an equatorial instrument. An instrument somewhat resembling that of Dr. Littrow, and designed for use as a position micrometer was devised by Mr. G. P. Bidder, and is described by him in the Monthly Notices, Roy. Astr. Soc., for June, 1874. In this form of “ghost” micrometer, the image of the lines is formed by a unilateral oblique pencil of rays, and it would, probably, be difficult to avoid loss of definition, due to dispersion by the lenses of the eyepiece, as well as to preserve an invariable scale value, on account of the want of a sufficiently rigid connexion between the several parts of theinstrument. Any movement of the second prism of the optical train, as proposed for the purpose of transferring the system of “ghost” lines to any part of the field, would directly tend to alteration of the scale value, and introduce a variable parallax of serious amount. The instrument now to be described is one of several forms contrived with the object of avoiding the difficulties encountered by those who have hitherto worked at this subject, and of extend- ing the powers of the wire micrometer into the field occupied by the double image micrometer, by rendering the measurement of planetary discs and close double stars practicable without the production of interference phenomena, or the necessity of halving the light of the image, this last being a great objection to the use of the double image micrometer in the measurement of faint objects. At the same time the connexion between the several parts of the instrument is so rigid and permanent that variation in the scale value will be produced only by tempera- On a New Form of Ghost Micrometer. i ture, and the corrections thereby necessitated will be of the same order with those already familiar to observers. Plate IIL. figure 5, represents the most simple form of the in- strument hitherto devised by us, one-third of its actual size. Ex- ternally it consists of a pair of tubes, one in the axis of the telescope, and the other at right angles thereto. The first of these tubes is attachable to the draw tube by an ordinary ‘Tulley’ screw at S, and carries at its lower end the eyepiece E. The cross tube carries at one end a ‘ Reticule’ or wire frame F, movable or stationary, according to requirements, and at the other a cell containing a concave silvered mirror M, the radius of curvature of which is slightly greater than the distance between F and M. At the junction of the tubes is mounted (at 45° to F. M) a plane silvered mirror PP, perforated by an ellip- tical hole slightly larger than is necessary to allow the pencil of rays from the object glass to pass. Immediately below PP is in- serted a perforated achromatic lens LL to increase the conver- gence of the rays from M, thus diminishing the length of the eye tube, while forming an image of F at the focus of the object glass. F being illuminated by a faint external light the rays from it pass to M through the hole in PP, and being reflected by M in a cone of smaller angles are received on the inner edge of PP, and are thereby diverted into the eye-tube where they are still further condensed by LL and brought to a focus at F—the focus of the object glass. In Plate IV., fig. 7, is shown the original form which Mr. Grubb placed for trial in Mr. Burton’s hands. The principle is precisely the same, but greater compactness is obtained by bending back the rays as in Plate III, figure 5. Tn some cases the lens L (Plate IIL, fig. 5) may be unnecessary, in others it may be found better to use a plane mirror at M, and throw the whole work of forming the ‘ghost ’ images on the lens L. It is, of course, not necessary that the cross tube should be at right angles to theeye tube; and, in some cases, it may be ad- visable to use different arrangement of the parts. Ifit should prove to be difficult to adapt the instrument to any existing telescope on account of its length (4 inches), a Barlow lens can be inserted at S; but some forms of the apparatus have been de- vised, in which there is no cross tube, and the ‘ghost’ images 8 Scientific Proceedings, Royal Dublin Society. are formed by a perforated concave mirror, mounted in a tube capable of being pushed into the draw tube of the telescope. (See Plate III, tig. 6.) The best form of condensing lens L is under con- sideration, and it may possibly be found desirable to superachro- matize it to compensate for the undercorrection of the usual eye- pieces for lateral pencils. In two of its simplest forms including that represented in the figure, the ‘ghost’ micrometer has been severely tested by one of us (Mr. Burton) as regards the effect of the images of the lines upon the images of various celestial objects formed by an equatorially mounted objective of six inches aperture and six focal lencth. The objects scrutinised for this purpose were the following :—Lunar details, near the terminator, and fully enlightened ; Jupiter and Saturn, with their satellites; and numerous stars, both single and double. In all cases the result was the same, not the slightest change of form or false light beyond the limb (of the planets), being visible or even suspected when the objective images were brought in contact with or were occulted (covered) by the ‘ghost’ lines, powers up to 400 linear being employed whenever definition was suitable. The illumi- nation of the reticules employed was extremely easy, and readily adjusted to suit the brightness of the object observed. It was possible, with the direct light of an ordinary candle, unas- sisted by any optical arrangement for rendering it parallel or convergent, to increase the brightnes of the lines sufficiently to make them clearly visible against the brightest parts of the moon’s image. The reticules employed were systems of lines cut through an opaque film deposited upon glass. Suggested forms of “ Ghost” micrometers with their applications. In its most simple form, this micrometer will do duty as a transit eyepiece displaying dark lines on a bright field, or r. r., and can be fitted with reticules of any kind for mapping groups of stars, or details of the moon or planets, including of course circles for ring micrometer work. (1) By substituting for the reticule a wire micrometer with one or two screws, the instrument can be used (a) instead of an ordinary wire—or bifilar micrometer with bright field, On a New Form of Ghost Micrometer. 9 or (b) as a unifilar micrometer with bright lines cut through an opaque film; or (c) as a bifilar micrometer with bright lines, the object lines (at F), being in this case spider webs, illumi- nated by a Wenham paraboloid or other similar contrivance. (2) By splitting the plane mirror P centrally in the plane M.P.E., and mounting one-half on an axis perpendicular to that plane, attached at its upper end to a lever arm terminating in a sector actuated by an endless screw with divided head, a double set of “Ghost” lines might be formed by inclining the two parts of the plane P to another by a movement of the arm screw. One of these sets of lines would be stationary, while the other set would have its movement registered by the turns and parts of a turn of the endless screw. Of course the lines might be either dark on a bright field or bright on a dark field, the latter being best; for in the former case, the lines would not be black, but would be of half the brightness of the field. We have experi- mentally proved that the definition of the lines is practically unaffected by stopping off half the aperture of M or P, in a direction perpendicular to them, and that their brightness does not sensibly diminish for a considerable distance past the centre of the field. (3) By substituting diaphragms pierced with small circular apertures, as in the instrument of Professor Stampfer (vide Note at end), illuminated by polarized light variable in intensity and colour, this micrometer can be made available for photometric and colour comparisons of stars after the method of Zollner, and . not only can the field, in the case of bright field illumination, be illuminated with light of any desired tint, but, if bright lines are employed, they can be coloured as the observer may prefer, for there is always a superabundance of light, which is yet completely under control. The lines can be shown broken or continuous as may be desired. The first mentioned arrange- ment may be advantageous under some circumstances. A useful modification of the reticule mentioned above, would be a bright ring (photographed), divided into numbered degrees, and nearly of the same diameter as the field, which would assist materially in estimation of position angles when the faintness of the object viewed rendered measwrements impossible. 10 Scientific Proceedings, Royal Dublin Socrety. Lastly, when a slight loss of light is of no importance, a glass plate with plane and parallel sides, the preparation of which is a matter of no difficulty in the present state of practical optics, may be substituted for the plane mirror iP, with the advantage of securing a large field, which may be surveyed by a low power eyepiece, or by one of high power so mounted ag to be traversable over the whole field. Many other forms and modifications have occurred to us, some of which may eventually he found practicable, but we deem it unnecessary to crowd this paper with suggested forms which have never been tried, and some of which will probably be useless. The difficulties met with by Mr. Burnham, which originally drew the attention of one of the authors (Mr. Grubb) to this subject had reference mostly to adaptations of recording apparatus to micrometers, as he felt the great inconvenience of rising from his chair after making a bisection, probably in some most awkward position, to read his micrometer head and circles with the aid of a handlamp. We have had some experience of recording apparatus ° attached to circle microscopes, and while we believe in their feasibility, we question the desirability of such attachments to delicate instruments.* We believe, however, that the same end can be obtained by some simple adaptations to this new form of micrometer. It does not take much imagination to conceive an optical * In some cases the recording apparatus consisted merely of an arrangement for pro- ducing ink dots on an ivory head attached to micrometer head, and thus five or six observations could be made, and all read off together. In the case of a special micrometer, however, made for the Earl of Rosse, one of the authors (Mr. Grubb) adapted a peculiar system which has not been elsewhere described. The micrometer head terminated in a flat plate, represented in fig. 4 plate II., by the central circle a a. Surrounding this, and in same plane, was a ring, 6 65, which formed part of a wheel centered on the micrometer head, and by a simple contrivance caused to revolve once for every ten revolutions of head itself. Surrounding this again was another ring, ccc, stationary. The platesa a a, therefore, revolved with the screw directly, 6 bd at ten times this speed, and c c c was always stationary. In the centre was a small point, d, and on outside ring two smaller points, e¢ and f; A similar needle point was fixed in some part of each of the rings b 66 and ccc, as at y and #. A folding piece of brass, covered with cardboard or indiarubber, was hinged in such a position that a piece of paper could be conveniently applied to and stamped against the end of the micrometer head. The stamping produced five holes, de fgandh. A line drawn through d ef gave the zero, the angular position of g gave the whole turns of micrometer screw, and that of h, the angular position of the micrometer screw itself; or, in other words the reading of the micrometer head. In reading off these records the next day the paper was placed under a glass scale, divided in one annulus, to read the whole turns and on the other the parts of a turn, the point d giving the centre, and e and / the zero of the scale. On a New Form of Ghost Micrometer. iil arrangement of mirrors such, that after a bisection is satisfactorily made, images of the divisions of the micrometer heads and position circles: could be thrown into the field of the same eye-piece just as the image of the reticule is here thrown in, and then the read- ings of all the graduations could be taken without shifting the eye from the eye-piece of the telescope. Lastly, as to the source of illumination. The illumination of this micrometer is a much simpler matter than in any other form of micrometer for bright line illumination, on account of the small quantity of light required. Still, if some simpler plan could be contrived that would enable a source of faint light to be placed close to the micrometer, instead of having to throw it from a distance, or conduct it down the tube by mirrors, We. a great advantage would be gained. We are, therefore, engaged in ex- periments to investigate whether such illumination could not be obtained from platinum wire or carbon rendered incandescent by an electric current of low tension. ‘These experiments are mentioned to show that every branch of the subject is receiving due attention. Notre.—Since this paper was read we have had an opportunity of examining the original papers of Dr. Lamont, Dr. Littrow, as well as notes on a kindred instrument devised by Professor Stampfer of Vienna, by himself and by Herr Reslhiiber, Director of the Observatory of Kremsmiinster in Bavaria. Dr. Lamont used a glass plate, set trans- parently at a small angle with the optic axis of the telescope to intro- duce the image of the lines into the field of the eye-piece. Professors Littrow and Stampfer’s instruments are essentially similar, the images of the points or lines employed being formed by a small segmental lens immediately outside the cone of rays from the O. G., the lines or points used being external to the telescope tube and at one side of it, and the light from them directed to the image-forming lens by a small prism of total reflection. The beam of light was thus unilateral, and the prin- ciple of the instrument identical with that figured on Plate III., fig. 5. Professor Stampfer preferred bright points to bright lines, which last were used by Dr. Littrow. Il—ON A TRAVERTINE FROM BALLISODARE, NEAR SLIGO, CONTAINING A CONSIDERABLE AMOUNT OF STRONTIUM, sy EDWARD T. HARDMAN, F.c.s. [Read, May 21st, 1880. ] ALONG the shores of the minor bays which indent the coast near Sligo, there is often a considerable deposit of travertine, owing to the water which trickles over the limestone cliffs, dis- solving a portion of the carbonate of lime, and again depositing it in a porous form on the slope. Travertine is thus found in abundance at Drumeliff Bay, to the north, and at Ballisodare Bay, to the south ; and that at the latter place is interesting from the fact that it contains a very appreciable amount of the rare metal, strontium—probably the only instance in which it is known to occur in a recent calcareous deposit. The manner in which I noticed this is sufficiently curious to be mentioned. A silver-lead, and zine mine is at present being worked close by. A mining captain, who was brought from England to examine this, saw the travertine deposit, declared it to be zine ore, equal to anything he had seen in Spain, and took some specimens for analysis to England. The owner asked my opinion about it, and was incredulous when I pronounced it to be common travertine. However, eventually it was proved to the satisfaction of himself and his practical friend that it was nothing else. As I had been making some researches on the presence of zine in limestone rocks, I obtained some specimens for analysis, deeming it likely that from its proximity to the zinciferous limestone the deposit might contain a small amount of the metal. It proved, however, to contain not the slightest trace; but in the course of the examination the presence of strontium was clearly marked. It is easy to render this visible. Chloride of strontium is soluble in alcohol, and on ignition gives out the well known crimson. colour. On a Travertine from Ballisodare. 13 Taking some of the travertine, therefore, and placing it in a vessel with hydrochloric acid and alcohol, and then setting fire to the mixture, the presence of the strontium is at once apparent. The composition of the travertine is as follows :-— Carbonate of Lime, 5 D , . 91:05 Carbonate of Magnesium, . 3 2 . 4:50 Carbonate of Strontium, . - 3 5 Rh 895 Ferric Oxide and Alumina, . : 9 SO Insoluble residue, . 5 : 3 - 0:50 100:00 [| 4 ] TII.—PRELIMINARY NOTE ON THE MANUFACTORE OF PAPER FROM MOLINIA CQ@ARULEA, sy W. SMITH. [Read, November 15th, 1880.] THE botanical name of Melic Grass, which, with paper made from it, is exhibited,is Molinia cerulea, butfor the purpose of indicat- ing the use for which it is so well suited, I have called it “Irish Esparto.” The natural habitat of this grass or sedge appears to be bog, though it is sometimes found on clay land. It is easily distinguished by the seed stems, and by the absence of knots on these stems, except one close to the root. It grows in tufts, or rather mats, sometimes of considerable size, on the margin of bogs or sides of bog drains, ditches, and where the surface of bogs has been dug up, or in some way deprived of its natural growth of heath, &e., &e. It is generally known that Esparto is extensively used in the manufacture of paper, its use for this purpose may be said to date only from about 1860. It is as a paper making material, and a rival of Esparto, to which it bears some resemblance, that the Melic Grass promises to be of commercial importance. The paper exhibited has been made solely from the grass gathered this year on the bogs at Tyaquin, in the County Gal- way, on the estate of Mr. N.S. Richardson, who has made some experiments in cultivating the grass from seed. Last year Mr. Richardson sent me some of the grass, which I tested as to its paper making qualities ; and, though the quantity sent was small, and the trial was the first ever made, the result was so favourable that several Galway gentlemen joined Mr. Richardson in ex- perimenting on the best method of growing the grass. The infor- mation obtained from these trials and from observation of its natural habit, is that the grass grows well on partially drained bog, that when by accident or design the surface of the bog had been burned, there the grass was most luxuriant—in some cases springing up after a fire in places where it had not previously On the Manufacture of Paper from Molinia cerulea. 15 been observed. It seems to confine itself to flat bogs, as I have not found it, nor have [ met anyone who has seen it growing on mountain bogs. I have found it growing luxuriantly in the counties Galway, Roscommon, King’s, Kildare, and Fermanagh, and have received samples from Kerry and Donegal; so that it is probable the grass will be found more or less in all the flat bog districts of the country. It is said to have been formerly used in the Island of Skye for the manufacture of fishing nets. Tt is now used in Kerry for making creel handles, and is locally known as fedget grass. From the trials already made, both in quality and yield of paper, the grass appears at least equal to Spanish and Algerian Hsparto. Two independent trials—one in Scotland—are now in progress, which I have no doubt will confirm the favourable re- sults already arrived at. . From 1860 to the present time the use of Esparto has been gradually increasing, and now the import amounts to nearly 200,000 tons per annum, at prices varying from £5 to £10 per ton, according to quality and supply. As each year the yield per acre of Ksparto diminishes, to keep up the supply, it has to be gathered from a constantly extending area; and as the American paper makers have now begun to use Esparto, the supply to Eng- land is likely to be diminished or the cost increased. There are in Ireland upwards of 1,000,000 acres of flat bog, at present useless for any agricultural purpose. The entire of this area might be made to grow “ Irish Esparto.” Mr. Richard- son estimates the yield to be about half a ton to the statute acre if grown as a crop; and, therefore, to supply the English market, some 400,000 acres of what is at present a wet spongy mass would require to be drained, and, as considerable quantities might be exported to America, the area of bog to be drained need not be limited by the home demand. One obstacle to the drainage of bogs has hitherto been that there was no known crop of any value which could be grown on partially drained bog. The Melic Grass, which is a perennial,’ supplies this want, and there is now no reason why a large portion of these worse than useless bogs should not be drained, and the climate not only of their own immediate neighbourhood, but also of the country in general, be improved. 16 Scientific Proceedings, Royal Dublin Society. As the value of the grass at a railway station, canal, or seaport would be at least £3 per ton, its cultivation is worth the atten- tion of bog owners, and of exceptional assistance from Government, by loans for drainage through the Board of Works, at the lowest possible rate of interest. The cost of draining 400,000 acres, so that they might grow Melic Grass, would not amount to one million sterling, as the partial drainage of deep bog, sufficient to prevent the accumulation of stagnant water on the surface, is comparatively an easy matter. In addition to the employment which would be given in culti- vating the grass, another industry might be created by making the grass into “paper stock.” Wherever a sufficient quantity might be grown, peat being used as fuel, the quantity of material to be exported would be considerably reduced, whilst the value would be more than doubled. It is even quite possible that it might be cheaper to manufacture the Caustic Soda which would be required on the bog, than to import it from England, as on a bog, turf is certainly a cheap fuel. ee ea IV.—NOTES ON SOME NEW OR RARE IRISH HEPATICA, BY DAVID M‘ARDLE. Puates 5 aAnp 6. [Read, November 15th, 1880. ] Iv is now more than four years since the late Dr. Moore read before the Royal Irish Academy his “ Report on Irish Hepaticze,” the result of many years research and investigation of this interesting tribe of cryptogams. In this paper he enumerated 137 species, and appended to it a list of all previous papers and works relating to the Hepaticee of Ireland. Since the publication of that Report* a few additional species have been determined, and new localities for some of the rarer ones have been discovered, which were hitherto confined to one locality. The record of these additions forms the subject of the present paper. I had the honour of accompanying the late Dr. Moorein many of his excursions through the country in search of Hepatice and mosses, and remember that on one of these occasions when collecting on the damp sandy flats at Malahide where the rare Codonia Ralfsit and Palavicinia Hibernica are found, he pointed out to his son, Mr. F. W. Moore, the present Curator of the Royal Botanic Garden, Glasnevin, and to me, a single plant of the rare Scalia Hookeri (Lyell) B. Gray. This unique speci- men we unfortunately lost before reaching home, and conse- quently had only the opportunity of examining it in the field with a pocket lens. There can be no doubt as to its being the right plant, and probably it occurs in some quantity in the locality where before long we hope to make a careful search, and endeavour to verify the station. The only authority for record- ing Scalia Hookeri as an Irish plant was from a small portion collected at Connor-bill near Dingle, county Kerry, in 1873, by Dr. Lindberg of Helsingfors. To the genus Cesia I have added two species hitherto unknown to occur in Ireland, it being held by many good botanists that we have but one—viz., C. crenulata, Gott. When looking over the specimens in the Herbarium at Glasnevin, there were two packets containing specimens which | * Proceedings of the Royal Irish Academy, Vol. 2, Ser. 11—Science, p. 591. Scien. Proc., R.D.S8. Vou, O1., Pr. 1. Cc 18 Scientific Proceedings, Royal Dublin Society, thought different from the type; I therefore sent them to Professor Lindberg, who identified them as C. coralloides and C. obtusa. Though closely allied to each other, they are nevertheless quite distinct from C. crenulata, and when our eyes get accustomed to their distinguishing characters they will be easily recognised, and no doubt will be found to be as widely distributed as the old species. I have made rough drawings of both species to enable the student to distinguish them. The material at my disposal for drawing was not’all that could be wished, having been a long time collected and sterile. A good description and figure of C. coralloides is given in Carrington’s British Hepaticee, Part I., page 9, PL I, Fig. 3. It is very rare in Scotland, and has a geographical range northwards to Lapland. J have lately re- ceived a packet of specimens of C. obtusa from Mr. J. Sim, who collected them on Mount Strade, Aberdeenshire, October, 1880, and they agree in every respect with the Irish specimens named by Lindberg. Cresta, Bennett Gray. Jungermannia. Lightfoot, Fl. Scot. 2, p. 786 (1770); Hook. Brit. Junger (1816). Cesia, B. Gray, in Gray’s Nat. Arr. Brit. Pl. I, p. 705, 1851. Gymnomitrium, Corda, in Opiz. Beitr. 1, pool, 1329) Involucral leaves several, Colesule wanting. Bases of the pistil- lidia immersed in the hollow apex of the stem. Antheridia axillary. Amphigastria none. Cesia corallordes, Lindberg. Resembling the common C. crenulata, Gott, but smaller and not so much branched, branches erect, clavate, of a dull white colour, growing in compact patches. Leaves closely imbricated, emarginate, margin plane with none of the cells projecting as in C. crenulata. Hab. Brandon Mountain, county Kerry—Dr. Moore, 1840. Cesia, obtusa, Lindberg. Closely allied to the preceding, stems erect, regular in outline, longer and more slender, very much branched, of a dark olive Some New or Rave Irish Hepatice. 19 colour. Leaves oblong, emarginate, sinus obtuse, margin plane, closely imbricated, more so than in the last, and with difficulty detached perfect. Hab. Mwellrea Mountain, county Mayo-- Dr. Moore, 1874. — Lejewnen patens, Var. cochleatu, Spruce. Hab. Glenfarm demesne, county Leitrim, 1875; Kylemore, county Galway, 1874, and on Benbulbin, county Sligo, 1871—Dr. Moore. This very distinct variety is generally found growing on the larger Hepaticze, such as Radula, Frullana, &e., and creeping amongst the branches of Thamiwm alopecurum. It at first sight appears to be distinct, but when a patch is closely examined where it is growing, some stages of its growth are to be found so close to the normal form as to show that they cannot be separated from it. — Lejewnen flava, Swartz. LL. cavifolia 6 planiuscula, Lindberg. Hab. Cromaglawn, Killarney, 1873—Dr. Moore. Closely allied to Z. Moorei, Lindberg, but is more branched, leaves more closely placed. Amphigastria smaller and more cordate at the base. Formerly collected at Killarney by Dr. J. F. Mackay, but not again observed until rediscovered by Dr. Moore in 1873. Cephalozia bicuspidata y ulogvnosa, Nees. Syn. Hepat., pp. 139. O’Sullivan’s Cascade, Killarney, July, 1869, and in same year on wet bogs near Kylemore, county Galway, Dr. Moore. Killakee Glen, Dublin Mountains, May, 1874. Loughbray, county Wick- low, September, 1877. This form is new to the Irish Flora. Cephalozia cladorhizans, Spruce. C. obtusiloba, Lindberg. Jungermannia inflata 6 fluitans, Synops. Hepat., p. 105, n. 68. Hab. Wet bogs near Kylemore, county Galway, May, 1869— Scien. Proc., R.D.S. Vou, 111., PT. 1. Cc DA 20 Scientific Proceedings, Royal Dublin Society. Dr. Moore. Bracklin bog, near Killucan, county Westmeath, growing on Sphagnum rubellum and S. cuspidatwm. Apparently closely allied to J. inflata, the stem is unbranched or rarely branched, attenuated, flagelliferous, of a bright green colour, leaves distantly placed, divided to about one-third of the leaf into two obtuse lobes. This is also new to the Irish Flora, but it is well known on the Continent. The specimens collected in both the localities mentioned above are covered with the Zygogoniwm ericetorwm one of the conjugate algze, which appears to injure the leaves, and adheres so closely to the stem that small portions might be mistaken for amphigastria. A figure of this plant is given in Plate VI. Scapania curta, Dumort. Jungermannia nemorosa 6 denundata Hook. Brit. Jung, (Bs ally Hab. Upper Lough Bray, county Wicklow, 1879. Growing on the decaying stems of Ulex. This is a new locality for the species. Jungermannia (Aplozia) cuneifolia (Hook.), Dumort. Hab. Connor Hill, near Brandon Mountain, county Kerry, 1877. Growing parasitically on Frullania Tamarisci. This curious minute species, which is very rare in Ireland, was previously confined to Killarney. It may be known from all the other species by its curiously wedge-shaped leaves. Jungermannia (Lophozia) ventricosa, Dicks. Hab. Connor Hill, near Brandon Mountain, county Kerry, though widely distributed is rare in the county Kerry. Amongst the various communications recently sent to Glas- nevin, the most interesting was one containing a quantity of good specimens of Anthelia Turnert, Dumort. It was found by G. Davies, Esq., in North Sussex. This plant was hitherto confined to Ireland, where it was first collected by Miss Hutchins, near Bantry, county Cork, in 181], and was not reported to have Some New or Rare Irish Hepatice. 21 been collected by any one until Dr. Lindberg found it at Killarney, in June, 1873. The rare Lejewnea patens and L. Moorei both occur in Scotland, having been found by Mr. J. Sim in Aberdeenshire. From Mr. Sim I have also received many specimens of Scottish Hepatice, amongst them I may mention Cephalozia elachista ; Jungermannia cordifolia, J. capitata, and J. Dicksoni, all rare Trish plants, which show an interesting geographical distribution. Reference to Plates. Plate V. Fig. I. Cesiacoralloides, Lindberg. Plant natural size ; 2, highly magnified ; 3, outline of leaf highly magni- fied ; 4, cells magnified x 250 diameters. Fig. II. 1, Cesia obtusa, Lindberg. Plant natural size ; 2, highly magnified ; 3, leafand cells, x 250 diameters. Plate VI. Fig. IIT. Cephalozia cladorhizans, Spruce,—C. obtusiloba, Lindberg. 1, Plant natural size; 2 and 3 highly magnified ; 4, leaf and portion of stem highly magnified. [ 22 ] V.—NORTH-AMERICAN BIRDS CROSSING THE ATLANTIC, BY PERCY EVANS FREKE. [ Read, November 15th, 1880. ] THE following tables are based upon a paper which I read before this Society last year, entitled “ A comparative Catalogue of Birds found in Europe and North America,” (vide Proceedings, Vol 2, n.s., p. 873). In the present article I have selected only those occurrences which seem to be generally accepted as authentic by the best authorities. This has entailed a very large reduction in the number of instances quoted, which now amount to 394, and it also curtails considerably the list of species by the omission of such birds as the Nyctale acadica and Scops asio. Others, also, such as Chen hyperboreus and Puffinws obscwrus, may have come to us across the Atlantic, yet as they inhabit Africa or Asia as well as America, they have been omitted here, as have such birds as Thalassidroma oceanica which make the ocean their home, with a widely extended range. I have, how- ever, included Xema sabinie, for although it probably may be considered as belonging to northern Asia, yet our European specimens being taken in the west, may I think fairly claim to have come to us from America, especially when we consider the prevalence of strong winds from the west, and the greater liability of stragglers to be found east of their natural habitat. In the case of Bernicla canadensis, I have only included the two ex- amples which have occurred at the Faroe Isles, as its presence with us in numbers as an ornamental waterfowl throws great doubt upon its occurrence here in a really wild state. In preparing this paper I have received the greatest assistance from the excellent article of Mr. Dalgleish, * which has lately ap- peared in the Bulletin of the Nuttall Ornithological Club,and which may now be considered as the standard authority on the subject. As a means of arrangement I have placed the different species under the three heads of land birds, waders, and swimming birds, as I think this plan best agrees with the manner in which they have been influenced by the circumstances attending their im- migration. * “List of Occurrences of North American Birds in Europe,” by J. J. Dalgleish. Bulletin of the Nuttall Ornithological Club, Vol. V., Nos. 2, 3, and 4 (1880). North-American Birds crossing the Atlantic. 23 Of land birds there are 120 occurrences belonging to thirty-one species. Of these one occurred in Iceland; and thirty-three including fifteen species, only in the British Isles. Fifteen belonging to seven species have been found in Ireland, of which Ceryle aleyon has occurred nowhere else in Europe, Coccyzus erythrophthalmus only in Ireland and Italy, and Astur paluwm- barius Var. atricapillus only in Ireland and Scotland. Twenty-seven occurrences, of ten species are recorded from Scotland, of which Buteo lineatus has not occurred elsewhere in Europe. England is credited with fifty-three cases belonging to eighteen species, of which twelve including seven species, have occurred nowhere else in Europe, and Turdus migratorius has been found only in England in the British Isles, although it has also occurred on the continent of Europe. Progne subis is recorded only from England and Ireland, and Regulus calendula, Zonotrichia al- bicollis, Surnia ulula Var. hudsonica and Nauclerus furcatus only in England and Scotland. Nine instances belonging to eight species have occurred in the small island of Heligoland, and of these Harporhynchus rufus, Galeoscoptes carolinensis, Anthus ludovicianus, Dendroica virens and Charadrius virginicus have occurred nowhere else in Hurope. We have records also from Spitzbergen, Sweden, Germany, Pomerania, Austria, Belgium, Switzerland, and Italy. Of those occurrences where I have been able to ascertain the monthly date, eight have taken place in February ; six in March; eight in April; four in May; four in June; one in July; two in August ; five in September ; eleven in October ; five in November ; and nine in December. Thus in the six months from October to March inclusive, thirty-nine out of sixty-three, or nearly sixty- two per cent. of all the occurrences have taken place; besides which there are five marked spring; two summer; ten autumn, and one winter. Forthe spring (March, April, and May) twenty- three cases, as compared with thirty-one for the autumn months (September, October, and November). Of wading birds 125 instances are recorded, comprising sixteen species. One Numenius hudsonicus has occurred in Iceland. In Ireland we find twelve occurrences, including six species, of 24 Scientific Proceedings, Royal Dublin Society. which Porphyrio martimicus has been found there only. In Scotland there are sixteen cases of seven species, of which Rhya- cophilus solitarius has occurred nowhere else in Europe. In England there are eighty-two occurrences, including twelve species, of which one of Gallinago wilsoni, two of Tringa minu- tilla, and three of Gambetta flavipes have occurred in England alone, Tringa maculata only in England and Scotland, and Tringa fuscicollis only in England and Ireland. On the continent of Kurope, one occurrence each is reported from Heligoland, Holland, Malta, Italy, and Spain ; two from Germany, and five of three species from France. In those cases in which I have obtained the monthly date, I find that two have occurred in January, two in March, one in April, six in May, one in June, two in July, five in August, twenty in September, twenty-eight in October, thirteen in No- vember, and five in December. Therefore in autumn, including September, October, and November, we have received sixty-one out of the whole eighty-five occurrences, or more than 71 per cent., besides four cases marked autumn and one winter, to con- trast with only nine in spring. Of swimming birds there are 149 instances of twenty-two species. From the Faroe Isles we have seven records of three species. From the British Isles 103 records of nineteen species, of which thirty-seven of nine species have occurred there only. In Ireland there are twenty-four instances of seven species, of which Chen albatus and Anous stolidus have occurred nowhere else in Europe. Scotland is credited with twenty-three cases belonging to nine species, of which Cygnus americanus has occurred there only, and Clangula albeola only in England and Scotland. From England are recorded fifty-six cases, including sixteen species. Of these eight cases of four species have occurred no- where else in Europe, and one, Fuligula affinis only in England and Holland, and another, dstrelata hesitata, only in England and France. From the rest of Europe thirty-eight occurrences, belonging to twelve species, are recorded from Spitzbergen, Munsterland, Sweden, Russia, Heligoland, Holland, France Gncluding Picardy) North-American Birds crossing the Atlantic. 25 Germany, Holstein, Austria, and Italy; Phaleris psittaculus having been found only in Sweden, and Uria columba only in the Spitzbergen seas. Where I have ascertained the date, I find that, out of ninety- two occurrences, six have taken place in January, six in February, four in March, three in April, four in May, six in June, one in July, eight in August, twelve in September, fifteen in October, five in November, and four in December, while one is marked spring, one summer, four autumn, and twelve winter. Altogether twelve instances in spring as against thirty-six in autumn. Concerning the routes and means by which these visitors have reached us from America I can say but little* A few may have escaped from aviaries or from ornamental waters, and in our climate, having met with surroundings not very different from those of their native land, and having been for some time at liberty, and successfully accomplished their moult, they may have become indistineuishable from a purely wild bird. But I am of opinion that their number is but few. Among the land birds it is highly improbable that the small warblers, the cuckoos, the kinefishers, and others, which are seldom or never kept in confine- ment, should have been brought over here as caged birds, and the large percentage of all which occur in the latter part of autumn or in winter (especially among the waders) would lead us to suppose that they were members of the great flocks of American birds which breed every summer in the north, where the Atlantic is contracted to its narrowest limits, and the eastern land most nearly approaches to the west. On their return southward their numbers are composed largely of young birds who are seeking a land where they have never been before, and who, from their youth, are less able than their parents to contend with rough weather and contrary winds. Adverse gales carry them far to the eastward, and, blown out of their course, their return is im- possible against the strong westerly winds which prevail so much at this time of the year, and by which they are borne irresistibly eastwards, a few of those who survive finally reaching our shores in company with our own migrants returning from the north. The comparative absence of American visitors from the flocks miorating northward in spring along our coasts, is easily accounted * On this subject vide Professor Baird’s article in the “ American Journal of Science and Art,’ Vol. XVI. May, 1866. 26 Scientific Proceedings, Royal Dublin Society. for by the reverse of the conditions referred to above. The birds are older and stronger ; the Atlantic further south is a great expanse of ocean, across which few birds, whose home is not upon the open sea, could ever pass unaided, and the easterly winds which so often prevail in spring would also probably prevent, even the most aquatic of the American birds, from visiting us at this season. The very large proportion of these visitors which have been recorded from the British Isles, especially from England, as com- pared with the rest of Europe, is most striking; but this arises probably from the number of reliable observers being much greater in England than upon the Continent. In conclusion, the most decided result which I have obtained is the remarkable preponderance in the number of birds which have visited us during the autumn and winter months, which I pro- pose to join together as representing the autumn migration, both because many of the birds must have arrived upon our coasts in autumn, although not captured or recognised until long after- wards, and others have been driven to us from time to time during the winter, under the pressure of cold winds, snow, or a continu- ance of unusually severe weather. Altogether we have forty-two arrivals for the spring migration, during March, April, and May, to which I think we may fairly add the nineteen more instances in Juneand July, making sixty- one. While for the autumn migration there are 132 in September, October, and November, to which, if we add the fifty-four winter occurrences from December to February, we shall have 168 to represent the autumn migration, which appears to be the period during which we receive by far the greater number of our Trans- atlantic visitors. TABLES SHOWING NORTH-AMERICAN BIRDS WHICH HAVE CROSSED THE ATLANTIC. 28 Scientific Proceedings, Royal Dublin Society. Lanp Brrps. Total |Iceland No pe No. of | and Ire- | Scot- | Eng- Continent of Occur-| Faroe | land. | land. | land. Europe. rences.| Isles. 1 | Turdus fuscescens, . 1 1 Pomerania. 2 | Vurdus swainsoni, 3 1 Heligoland. 1 Belgium. 1 Italy. 3 | Turdus pallasi, : 3 ; 3 1 Heligoland. 1 Germany. 1 Switzerland. 4 | Turdus migratorius, ‘ : 6 : : ; 1 1 Heligoland. 1 Germany. 3 Austria. 5 | Harporhynchus rufus, 1 1 Heligoland. 6 | Galeoscoptes carolinensis, il 1 Heligoland. 7 | Regulus calendula, 2 1 1 8 | Anthus ludovicianus 2 5 2 Ieligoland. 9 | Dendroica virens, 1 : 1 Heligoland. 10 | Progne subis, 2 1 6 il Ii | Hirundo bicolor, 1 1 12 | Vireosylvia olivaceus, 2 2 13 | Loxialeucoptera, . : : 11 a : 4 a 14 | Zonotrichia albicollis, . F 2 1 1 15 | Agelaius pheeniceus, 9 i 11 2 8 1 Italy. 16 | Sturnella magna, : 3 3 ° 3 17 | Ceryle alcyon, . : : : 2 A 2 : 18° | Coccyzus americanus, € 2 2 3 1 Belgium. 19 | Coceyzus erythrophthalmus 2 1 4 ‘ 1 Italy. 20 | Picus villosus, : 3 : ‘ 3 21 | Picus pubescens, . ; i 1 1 22 | Colaptes auratus, 1 : 1 23 Surnia ulula var. hudsonica, 4 : 2 2 24 | Falco candicans, . : 30 1 6 13 9 1 Spitzbergen. Iceland. 25 | Nauclerus furcatus, 0 9 5 5 5 1 4 26 | Astur palumbarius var atrica- 3 : 2 1 pillus. 27 Buteo lineatus, ; 1 3 : 1 5 28 | Haliaétus leucocephalus, * ; 1 5 : : i 1 Sweden. 23 | Ketopistes migratorius, . 7 - 1 1 4 1 Austria. © 30 | Charadrius virginicus, . é 1 : . 5 1 Heligoland. 31 Aigialitis vociferus, 1 3 1 120 1 15 27 53 24 * Dalgleish. Bull. Nutt, Orn, Club, Vol. V., No. 3, p. 143. North-American Birds crossing the Atlantic. 29 Lanp BIrRps. No. Jan. | Feb. | March.| April.) May. | June. | July. | Aug. | Sept. | Oct. | Nov. | Dec. | 1 Xe : 2 A 69 47 Autumn 43 3 4 Autumn} 3 = 25 4 Spring.| 76 0 ‘ 74 51 Autumn 46 20 5 4 : x s Autumn 38 6 40 17 A 5 . jSummer) 52 o ° 9 : 8 58 5 ; 0 3 : 51 '9 58 '10 il 2 3 : : : 12 . 5 : 6 59 59 13 4 41 F 49 ; ‘ 6 0 45 : 5 F 49 59 44 . 49 49 59 49 14 0 : 72 . 0 : 0 67 , 0 0 , 15 “ 5 66 . 65 43 : 0 Autumn) 44 0 63 67 66 74 16 A 6 : 0 17 : 5 0 6 . 0 ° n : 45 45 1s F 0 : 3 i S F . |Autumn) 25 Autumn 32 70 74 19 y 5 6 ; : : : : 71 5 20 : : ° 21 9 6 5 6 5 0 : 5 F : 36 22, : . 9 5 , A : . |jAutumn] 36 , 23 5 5 30 0 : . 0 47 0 . 68 5 24 . 37 66 75 ° 5 61 5 Autumn} 62 ume 47 37 76 76 Autumn} 62 54 38 48 Spring. 62 Winter. 68 63 |Spring.-| 63 25 5 . fe O38 . Summer] 33 O 05 43 26 3 70 |Sprin-.| 69 Spring. 70 27 63 . 28 , ‘ : : 5 : c 0 : 6 3 6 29 6 c A o 0 44 . Z é 76 . 25 30 : O 47 31 57 8 6 8 4 4 1 2 5 11 5 9 In eases where more than one bird has been taken on the same occasion, or from the same flock, I have included the dates within a bracket. 30 Scientific Proceedings, Royal Dublin Society. Wapine Brrps. Total |Iceland N No. of |} and lre- | Scot- | Eng- Continent of ep iat Occur-| Faroe | land. | land. | land. Europe. rences.| Isles. 1 | Botaurus lentiginosus, 5 17 3 6 8 2 | Gallinago Wilsoni, . 1 < 1 3 | Macrorhampus griseus, . 15 3 9 3 France. 4 | Tryngites rufescens, 20 : 4 1 13 1 Heligoland. 1 France. 5 | Symphemia semipalmata, 3 : : 3 France. 6 | Tringa maculata, . 19 1 18 7 | Tringa minutilla, 2 2 8 | Tringa fuscicollis, 14 1 13 9 | Gambetta flavipes, . 3 3 10 | Rhyacophilus solitarius, . 1 1 : 11 | Tringoides macularius, 11 2 2 6 1 Germany. 12 | Actiturus longicaudatus, 10 6 6 1 Germany. 1 Holland. 1 Italy. 1 Malta. 13 | Numenius hudsonicus, 2 Ihe . 0 9 1 Spain. 14 | Numenius borealis, . 5 1 2 2 *Iceland. 15 | Porzana carolina, 1 ‘ 1 16 | Porphyrio martinicus, 1 1 125 1 12 16 82 14 North-American Birds crossing the Atlantic. WADING Brirps. No. Jan. Feb. |March.| April.| May. | June.| July. | Aug. | Sept. | Oct. | Nov. | 1 73 0 C 5 6 5 i 44 45 70 54 70 68 75 77 Autumn 04 Autumn 62 2 5 f 0 6 5 5 a 63 - ; 3 0D 6 O 9 é 6 6 : 35 01 58 45 57 62 Autumn 3 4 29 6 82 51 26 64 47 41 3 46 60 70 Autumn| 39 6 68 : 6 5 40 55 0 53 53 30 65 41 70 53 On, 67 70 | 70 70) 70 71 7 69 53 , 38 : , 46 70 ) 54 70 ! 57 70 70 70 of 70 9 58 Winter 71 10 6 3 11 49 75 63 28 67 28 66) a a 66) 12 55 5 6 c A . Q : 3 51 65 59 65 79 13 72 - , 14 55 70 78 15 64 6 16 ‘ , 6 45 iD, 2 1 6 i 2 5 20 28 13 Dec. 32 Scientific Proceedings, Royal Dublin Society. SwimMMING Brrps. Total |Iceland N No. of | and Ire- | Scot- | Eng- Continent of 2: ivy Occur-| Faroe | land. | land. | land. Europe. rences.| Isles. 1 | Cygnus americanus, (?) il 1 6 2 | Cygnus buccinator, 4 4 3 | Chen albatus, . 5 5 4 Bernicla canadensis, 2 2 Faroes. 5 | Mereca americana, . 7 y 1 3 1 France. G6 | Querquedula discors, 4 1 2 1 France. 7 | Querquedula carolinensis, 2 2 S | Fuligula collaris, 1 o . 1 9 | Fuligula affinis, 2 : 1 1 Holland. 10 =| Clangula albeola, 5 2 2 3 11 | Gdemia perspicillata, . 344) 3 1 10 4 3 Russia. Faroes. 3 Sweden. 1 Heligoland. 8 France. 12 | Mergus cucullatus, . 15 c 2 4 9 13 | Phaleris psittaculus. 1 1 Sweden 14 | Uria columba, ] ; c 1 Spitzbergen. 15 Puffinus griseus, 9 2 1 4 2 France. Faroes. 16 | Aistrelata hesitata, 2 1 1 France. 17 | Larus atricilla, 6 4 1 France. 1 Austria. 18 | Larus philadelphiz, 7 3 1 2 1 Heligoland. 19 | Xema sabinii, . 32 8 2 13 2 Munsterland. 1 Holstein. 1 Heligoland. 1 Holland. 1 Picardy. 3 France. 20 | Sterna fuliginosa, 5 2 1 Germany 1 France. 1 Italy. 21 | Sterna anestheta, 1 < 1 22 Anous stolidus, 3 3 149 d 24 23 56 38 * Including one, locality unknown. = OOHNH® oO BR OW = = 12 13 14 15 16 17 i8 19 North-American Birds crossing the Atlantic. : 2 | 28 41 | 44 64 ie Glen 78 75 66 76 70) 705 Spring. 45 48 March.| April. 70 75 Swimmine Brrps. May. | June. 76 46 47 Summer] 58 17 64 ScrEN. Proc., R.D.S. Vout, 11., Pt. 1. July. Aug. 56 28 Sept. 56 Autumn 72 Autumn Autumn 78 Autumn 78 Oct. 79 Novy. 69 75 Winter. ‘Winter. Winter. Winter. Winter. Winter. Winter. Winter. 33 ih f y : aS ny Ty We ae | ; F rie AL, } ay aR eae een Gate idee ae hv 4 Fi apni) ! Hi { eae A Gi 7 \ ‘ ton Pierre OS aAT yiem ia al Dh oe ( 4 Ae ee EOD aerti O , } p 5 22 62 43 34 66 63 37 66 58 72 66 67 67 70 67. Autumn} 39 78 Autumn 66 78 20 4 Re 6 S 54 0 4 : . 3 69 21 ‘ : 3 ‘ 5 ; : = 75 6 , 5 22 5 - . : : : 6 2 c ; - : 6 6 4 3 4 6 1 8 12 15 5 4 Scren. Proc., R.D.S. Vou, u1, Pr, 1. D [ 84] VI—ON THE GEOLOGICAL STRUCTURE OF THE © NORTHERN HIGHLANDS OF SCOTLAND; BEING NOTES OF A RECENT TOUR, sy EDWARD HULL, LL.D., F.R.S., DIRECTOR OF THE GEOLOGICAL SURVEY OF IRELAND. Puates 9, 10, anv 11. [Read, December 20th, 1880.] The following notes were made during a tour in the North Highlands of Scotland during the spring of 1880, under the guidance of Professor Geikie, Director of the Geological Survey of Scotland, in company Mr. R. G. Symes, of the Geological Sur- vey of Ireland, and several other friends; the object being to observe the character of the geological formations of that district, with a view to a comparison with those of the north-west of Ireland, where the operations of the Survey are about to com- mence.* The author could not hope to be able to communicate much information (if any) absolutely new, but the physical features and geological phenomena proved of such interest, and of so re- markable a character that he hoped a brief outline of his obser- vations would not prove unacceptable. The course taken was as follows :—Reaching the village of Garve, near Dingwall, by the Highland Railway, the road lay right across that part of Scotland to the head of Loch Broom and Ullapool, through the beautiful glens of Braemore, which open on the head of Loch Broom. Thence to Inchnadamff, which lies at the head of Loch Assynt, and close to the base of Ben More, Canisp, and Quenaig. Thence to Scourie and Rhi- conich, which is only a few miles distant from Cape Wrath, and then across Scotland to Lairg, where the railway to the south was reached. By this route two traverses across the country, at a distance of about thirty miles from each other, were made, and the western coast for a distance of about fifty miles was examined. The geological structure of this district has only recently been clearly and definitely demonstrated by the researches of the late * This visit was an official one, made with the sanction of the Director-General. On the Geological Structure of the Highlands of Scotland. 35 Sir R. I. Murchison,* following on the discovery by Mr. Charles Peach, of Lower Silurian fossils in the Durness and Assynt limestone (1854). Previous to that period the crystalline schists of the Central Highlands were considered to be of “ pri- mary” age; and the red sandstones and conglomerates of the north-west coast were supposed to be of the same geological age as those of the north-east coast—namely of “ Old Red Sandstone ” age. Sir R. I. Murchison demonstrated that the red sandstones and conglomerates of the west lie beneath all the crystalline schists, quartzites, and limestones of the Central Highlands, to which they are unconformable,t and as the latter are shown, by the fossils found in the Assynt (or Durness) limestone, to be of Lower Silurian age, the underlying sandstones are inferred to be representatives of the Cambrian, and the fundamental gneiss and schists, which underlie the Cambrian, are also inferred to be representatives of the Laurentian group of Canada, which lies at the base of the Cambrian and Silurian rocks of that country. The general section may be stated as follows :— FoRMATIONS OF THE NorTHERN HIGHLANDS. Lower Silurian Beds, probably from 7,000 to 10,000 feet. Approximate thickness . ‘ bs s : in Feet. (a.) Gneiss, quartzite, mica-schist passing down into the Upper Quartzite of Benmore in Assynt, . (over) 5,000 (6.) Ribband glossy slates and flagstones, 5 . (about) 500 (c.) Assynt limestone—upper part yellowish anid dolomitic in places ; lower white, and full of cavities like casts of fossils, but rarely with fossils themselves, . . 100 to 1,000 (d.) Ferruginous sandy flags, shales, and bands of limestone, containing “‘ fucoid ” markings, d 3 . 100 to 200 (e.) Lower Quartzite ; purple, grey, and white quartzite, the upper beds penetrated by annelid burrowings, . 500to1 ;000 (Great hiatus and unconformity.) Cambrian Beds. Red and purple sandstone, sometimes pebbly, and towards the base passing into a conglomerate, with large pebbles and blocks of quartz, quartzite, jasper, felstone, gneiss, &c., in thickness from i : ; : F - Oto 3,000 * Quart. Journ. Geol. Soc., London, vols. xv. and xvii., 1858-61. +“ Siluria,” 4 Edit., p. 163, with section p. 169. Figures of the fossils are given by Murchison; they consist of Maclurea, Ophileta, Oncoceras, and Orthoceras. Scien. Proc,, R.D.S. Vou, m1, Pr, uw. D 2 36 Scientific Proceedings, Royal Dublin Society. Laurentian Beds. (a.) Upper part; hornblende schist, hornblende gneiss, and | Of great but hornblende rock, sometimes micaceous, and pene- | uncertain trated by quartz veins, E ; . ; thickness (o.) Lower part ; reddish gneiss, penetrated by veins of | om 20,000 granite or ‘“ pegmatite,” : : j feet.) The above may be regarded as the general succession of the rocks about Loch Assynt, and as far as Loch Broom towards the south, and Loch Laxford towards the north. It need hardly be stated that within this compass the beds vary much in thickness ;—but not in character. Throughout this region, and as far as the shores of Loch Dow, the Cambrian beds often rise into isolated precipitous hills or break offin grand escarpments and precipices, formed of nearly horizontal beds, rising tier above tier to elevations of 3,000 feet or upwards. Amongst the most remarkable is the north shoulder of Quenaig (Plate IX., fig. 3), which rises in the form of a great terraced buttress of red sandstone, its sides cut into deep gullies by mountain torrents, and accessible only by stiff climbing. The western shoulder of Suilven, as seen from the banks of the ferry at Kylesku, the remarkable escarpment of Benmore Coygeagh, (Plate IX., fig. 2), and the isolated truncated pyramid of The Stack (Plate IX., fig. 1), are all instances of the results of denudation, acting upon masses of horizontally bedded sandstone, in producing bold and massive scenery—differing in character from that of any of the formations either above or below. On reaching the Inn of Aultguish we came in sight of the mountains of Cambrian sandstone, at a distance of about ten or twelve miles to the westward, seen through a gap in the schis- tose rocks, and rising above Loch Broom in massive terraces; the horizontal stratification being clearly discernible by the aid of the binocular glass. The winter's snows still lingered on the summits and on the surfaces of the upper terraces. In front of them were the quartzite mountains of Ben Dearig and the neigh- bouring heights, generally capped with snow, which rise in bold rounded masses to an elevation of 3,551 feet. On descending towards the head of Loch Broom, along the valley of Braemore, we visited one of the most re- markable river gorges in the British Isles—a veritable On the Geological Structure of the Highlands of Scotland. 87 miniature canon (Plate X.,fig. 6), hewn by the mountain torrent out of slightly inclined beds of quartzite. Crossing on toa pretty little suspension bridge, thrown across the gorge by Mr. Fowler, c.z,, 60 feet in width, we looked down on the bed of the stream below, at a depth of 222 feet—that is, over three and a half times the width of the chasm at the spot where spanned by the bridge. We could follow with our eyes the chasm for a considerable distance above and below the bridge—the sides bounded by nearly vertical walls of quartzite, decorated with a natural growth of ferns, shrubs, and climbing plants—to the rapids by which the torrent descended from a loch situated higher up the glen. Look- ing down the stream, the chasm could be followed for about a mile before it opened out on the wide glen of Braemore. This miniature canon is itself situated in a much wider valley, bounded by mountains of quartzite, and im excavating it the stream has been facilitated in its operations by numerous nearly vertical joints, represented in Plate X., fig. 6, traversing the beds of quartzite in the direction of its course, as well as by smaller joints and fissures crossing these at obtuse angles. On descending along the shore of Loch Broom, we observed the horizontal beds of Cambrian sandstone, about 3,000 feet in thick- ness, appearing from below the inclined beds of quartzite on the southern banks ; and at the bridge of Ault Corry crossing a burn, about a mile from Ullapool, we had an opportunity of examining the “ Assynt limestone,” here only ten feet in thickness, for the first time,(Plate X.,fic.7).* Just outside of Ullapool we passed a bluff, showing the superposition of the lower quartzite on the red sand- stone and conglomerate of the Cambrian formation, with a clear unconformity in the stratification. We had thus in our first day’s journey made a transverse section of the Lower Silurian meta- morphic series of the Northern Highlands. It seemed clear to us that notwithstanding some slight fissures, some faulting, and possibly local foldings or inversions, we had traversed a gradually descending series of highly metamorphised beds of quartzite, gneiss, and schist, down to less highly altered beds in contact with the Cambrian, inasmuch as the Assynt limestone and the associated shales and flagstones could scarcely be recognised as having undergone metamorphic action. This was pointed out to * Murchison and Geikie, Quart. Journ. Geol. Soc., vol. xvii., p. 184. 38 Scientific Proceedings, Royal Dublin Society. us by Professor Geikie, and was readily acknowledged by his fellow travellers. On the second day our route from Ullapool to Inchnadamff, a distance of twenty-six miles, lay along a tract of country border- ing the Silurian and Cambrian formations. We passed under several grand escarpments of Cambrian sandstone; the most remarkable being that of Benmore Coygeagh (Plate IX., fio. 2), which faces the south, and terminates abruptly on the side next the ocean. The cliffs of horizontal sandstone rise to a height of about 3,000 feet, and are worn into deep gullies by the action of torrents. Nevertheless, the face of the escarpment rises like a great wall of red sandstone from the crest down for a thousand feet, where the slopes commence. A short distance further north we came in view of “The Stack,” an isolated mass of Cambrian sandstone, (Plate IX., fio. 1) also in horizontal beds; and, beyond, the heights of Coulmore* and Coulbeg, the former capped by the lower quartzite of the Lower Silurian series. Throughout this tract the “Durness Limestone” became more and more conspicuous as we proceeded northwards ; its thick- . ness increased till, on approaching the head of Loch Assynt, it expanded to about 1,000 feet, and rose in a conspicuous escarp- ment above the foot of the quartzite slope at the eastern base of Canisp. The presence of the limestone amongst the hills and valleys is marked by a band of verdure in the midst of the sterile tracts of heather formed by the quartzites both above and below. The limestone is generally weathered as white as chall, but in some places contains beds of dolomite weathering rusty brown. It is but very slightly altered, and frequently contains cavities exceedingly like those left by fossil shells; but with the excep- tion of an Orthis (?) found by Mr. Symes, we did not succeed in obtaining a single specimen of organic origin. On approaching Inchnadamff we skirted the eastern base of Canisp. This is an escarpment of Cambrian sandstone capped by quartzite, rising in a grand mural cliff facing the Atlantic. It terminates abruptly along the shore of Loch Assynt, and from the north shore of the loch the whole structure of the mountain is clearly revealed. The lower quartzite is seen to descend with a _ * Coulmore, together with Canisp and Suilven, are represented in one of the illus trations in Murchison’s“ Siluria,” 4 Edit., p. 170; and are graphically described by Hugh Miller. —— On the Geological Structwre of the Highlands of Scotland. $9 gentle slope across the truncated horizontal beds of Cambrian sandstone till the latter is cut out altogether, and the base of the Lower Silurian series rests directly upon the Laurentian gneiss.* The saction (Plate XI.,fig. 9 )taken across Quenaig, on thenorth shore of Loch Assynt, shows a similar structure amongst the formations. This disappearance of the Cambrian beds as we proceed north- wards is a remarkable feature in the physical geology of the district. The abrupt truncation of the sandstone at the edge of the Silurian quartzite, leaves no doubt that the formation was enor- mously denuded, even before the Lower Silurian beds began to be formed. At that period, however, the beds were tilted towards the west. Their present horizontal position being in consequence of the tilting towards the east of the Silurian beds. On approaching the deep inlet called Loch Dhu (or Dow) and the ferry of Kylesku, we passed near the base of the grand precipices along which Quenaig terminates towards the north. The bold bluffs of Cambrian sandstone rise about 2,000 feet, and form certainly the noblest cliffs I had seen (Plate IX., fig. 3.) Not- withstanding the great thickness of the formation (about 2,000 feet) in Quenaig, the whole had actually disappeared under our feet; and we could trace the Silurian quartzite margin resting directly upon the dark hornblendic schists of the Laurentian formation which extends from the base of Quenaig to the coast, and to the shores of Loch Dhu. From Kylesku to Scourie our course lay over a tract of broken and comparatively featureless country, highly gla- ciated by an ice-sheet which had moved towards the Atlantic. The rocks belong to the Upper Laurentian series, are chiefly hornblendic, highly crystalline in structure, schistose, and gneissose; occasionally schist of bronze mica was observed. Quartz veins are of frequent occurrence, and the beds are slightly crumpled, These rocks we had a good opportunity of examining during our last excursion northwards, on the following day, when we drove from Scourie to Rhiconich, a distance of twelve miles, the whole over Laurentian rocks. Our course lay over an exceedingly rugged country, with numerous little lochs, rock-basins, gullies, and deep ravines, Every where the rocks were exposed to view, presenting remarkably ice-worn surfaces, often strewn with boulders of quartzite and * The scenery at the head of Loch Assynt forms the Frontispiece to “ Siluria” 4 Edit. 40 Scientific Proceedings, Royal Dublin Society. of other rocks from the interior mountains. There is no mistaking the direction of the ice movement, which has here been west- ward; but it is only in protected spots that boulder clay. or moraine matter, is to be found. In general the rocks are bare to a remarkable degree, the ice having apparently swept the loose materials out into the ocean. On this day we passed under Ben Stack (Plate X.,fig. 4),a pyramid of dark Laurentian hornblendic gneiss, rising 2,364 feet above the sea, and the highest elevation (as I was informed by Professor Geikie) to which the Laurentian rocks rise on the mainland. We were also close under the escarpmentsof Ben Arkle (Plate X1I., fig.8) and Foinaven, the former 2,576 feet, and the latter 3,016 feet. These are formed of Laurentian beds, capped by Lower Silurian quartzite-—the whiteness of the latter contrasting with the dark tints of the former. As already stated, the Cambrian sandstones have been entirely denuded away over this part of the country previous to the deposition of the Lower Silurian beds. The section (Plate XI., fig.8) may be compared with that across Quenaig (Plate XI., fig. 9), in order that the changes in the stratification and physical features may be better understood. It should be observed that throughout the district we examined, the lower quartzite at the base of the Silurian series generally crops out as an elevated escarpment, towards the south, capping unconformably the Cambrian sandstone ; towards: the north, the Laurentian gneiss. As this escarpment crosses transversly the general drainage of the country, andthe course of those rivers which rise in the interior and flow westward towards the ocean, it is intersected by deep and wide valleys, so that it is exceedingly broken, and the lines of cliffrun far up the valleys towards the east. Coulmore, Canisp, Quenaig, Ben Arkle, and Ben Foinaven are all situated on the margin of the lower quartzite. On the other hand, the upper quartzite rises into equal, or still higher elevations such as Ben Dearig, Ben More in Assynt, Ben Hee, and Meal Horn, and generally forms the watershed of the North Highlands. The Cambrian beds generally form isolated, or partly detached masses. In no district I have ever visited do the physical features give more clear expression to the geological structure than in the North Highlands of Scotland. The Laurentian rocks extend all the way from Scourie to Bhiconich and Laxford Bay, and from thence to Cape Wrath. On the Geological Structure of the Highlands of Scotland. 41 On leaving Scourie, we pass transgressively over a descending series of hornblendic beds, sometimes micaceous, belonging to the upper part of the series. Sometimes the crystals of hornblende are here two inches in length. At Loch Naclaishfearn the beds are highly micaceousand garnetiferous. Atthe head of Loch Lax- ford we pass into the lower series, consisting of gneiss, well foliated, of red felspar, quartz and mica. Veins of pegmatite become more frequent as we proceed, and in crossing Laxford bridge, on the road to Rhiconich, fine sections are laid open in beds of gneiss penetrated by numerous dykes and veins of pegma- tite (a kind of granite), consisting of red orthoclase, crystals of pale yellowish or grey oligoclase, often of large size and showing the fine parallel lines which characterize a triclinic felspar. Along with the above are quartz and green mica. The pegma- tite veins traverse the gneiss and schists in all directions, some- times vertically, at other times obliquely, and cross the planes of foliation. They have been noted by Murchison as characteristic of the Laurentian beds ; but it is chiefly in the lower portion they become conspicuous. About Rhiconich, the dip of the beds is southwards or 8. 8. W., at various angles ; and as this dip was more or less prevalent all the way from Scourie, I estimate that the Laurentian beds must be over 20,000 feet in this district ;-— how much more no one can say as the base never appears. As we returned to Scourie by sea, we had an opportunity of sur- veying the coast cliffs of red gneiss, and had a fine view of Suilven, Canisp, and Quenaig towards the south, rising from a rugged plateau of Laurentian beds. The horizontal beds and terraces of red sandstone were easily discernible, even at the distance of over twenty miles.* The white dome of Ben More, and its adjoining quartzite ridges of Ben Arkle and Foinaven, bounded the horizon towards the west, while Ben Stack rose above the head of Loch Inchard (Plate X., fig. 4), which we were leaving behind, in the form of a dark shapely cone. Looking northwards over the heaving surface of the Atlantic we could see the islands of Ellen- a-Vullig in the direction of Cape Wrath. On the day following (2nd June) we left Scourie and again erossed the North Highlands from sea to sea, reaching the rail- * See View of these Mountains in Ramsay’s Phys. Geol., Gt. Britain, 5 Edit., p. 288. 42 Screntific Proceedings, Royal Dublin Society. way at Lairg. The road lay along the valley of the Laxford, and by the banks of Loch Stack, Loch More, and Loch Shin, crossing the low watershed under Ben Hee. As far as regards this journey I have only to observe that we had an opportunity of observing the general succession of the beds from the lower quartzite up- wards through the limestone series, the upper quartzite, into the metamorphic schists, and that, with occasional undulations in the stratification, there appeared to be a continually ascending series till we reached the granite of Lairg. Thus the results arrived at in reference to the succession of the beds between Scourie and Lairg were found to correspond with those arrived at by the more southerly traverse between Garve and Ullapool. Do Pre-Cambrian beds re-appear in the Central Highlands ? The question has been asked and answered in the affirmative by some geologists, “Do the Laurentian (or pre-Cambrian) rocks re-appear in the Central Highlands of Scotland after disappear- ing below the Cambrian sandstones and Lower Silurian quartzites of the western districts?” As far as the observations which we were enabled to make are calculated to throw light on the ques- tion, | can only state my own impression, that the evidence is against this view. Throughout the districts of Sutherland, Ross, and Cromarty which we visited, it was clear that the Laurentian beds must be buried at enormous depths underneath the Lower Silurian beds the further we proceed eastwards from the outcrop. It is quite possible that the whole of the Cambrian sandstones may be absent under the centre of the North Highlands. From the direction in which these rocks disappear through the effects of denudation, it was evident that even at a short distance below the upper quartzite they might be absent even when they were in greatest thickness at the western outcrop. The sections at Canisp and Quenaig are very suggestive of this. Therefore we may well suppose that under the centre of the North High- lands the Lower Silurian beds rest directly on a Laurentian floor ; and it seems to me highly improbable (though possible) that these latter rocks reappear at the surface, as there is clearly an ascending series all the way from the west towards the east of that part of Scotland. In the above statement I only refer to the region north of the Caledonian canal. Until the geological sur- vey of the Grampian range throughout the Inverness and Aber- On the Geological Structure of the Highlands of Scotland. 43 deenshire Highlands is completed, it will be impossible to affirm positively whether or not Laurentian beds actually reappear.* The two Unconformities. Bearing upon the geological history of this region, there is nothing more remarkable than the occur- rence of the two unconformities,—the lower, between the Lauren- tian and Cambrian beds, and the upper, between the Cambrian and Lower Silurian series. Both of these are of the most trenchant description. The abrupt truncations, and the sudden change of characters in the beds lying on either side of the boundary lines, suggest long intervals of time and great changes in the physical conditions under which deposition took place. In the first place, the Laurentian beds were metamorphosed, contorted, elevated out of the sea-bed, and denuded, before the Cambrian beds began to be spread over the uneven floor thus con- structed. Professor Ramsay considers the Cambrian sandstones to be of fresh water or lacustrine origin, and that glacial conditions were to some extent prevalent during their formation.} A large pro- portion of the pebbles and blocks found in the Cambrian beds is composed of fragments torn from the Laurentian masses. Of the Cambrian formation itis clear that only a fragment now remains in the North West Highlands. Its base is often visible,but its original upper limit never. It bears evidence of the effects of at least two great denudations. The first before the deposition of the Lower Silurian beds ; the second at a later period, probably often repeated, and coming down to recent times. The great buttresses of horizontal sandstone—against which the Lower Silurian beds rest—may be regarded as the eastern margin of continental land of the Lower Silurian period, embracing the outer Hebrides, and an unknown region beyond.|| At that period the Cambrian sandstones were tilted and the Lower Silurian beds * The only rock resembling Laurentian which we noticed in the central districts was a remarkable massive red gneiss, at Inchbrae, seven miles from Garve, ina N. W. direction, on the Ullapool road. This gneiss consists of red felspar, black mica, a little quartz and epidote. As far as its composition is concerned, it might be of Laurentian age; but in position it appears to be high up in the Silurian metamorphic series. + Phys. Geol. and Geog., Gt. Britain, 5 Kdit., p. 285, { Pres. Address, Brit. Assoc, Rep. 1880, p. 17. This view is founded on the dis- covery by Professor Giekie of glaciated surfaces of Laurentian rock passing underneath Cambrian sandstone at intervals all the way from Cape Wrath to Loch Torridon, together with large blocks of gneiss in the Cumbrian bed. || Ramsay, Phys. Geol. and Geog., ps 87. AA Scientific Proceedings, Royal Dublin Society, were in approximately horizontal positions. The case is different now, for the Silurian beds have an easterly dip, while the Cam- brian sandstones are nearly always horizontal. It is clear, there- fore, that the present horizontality of the latter is due to a second tilting in a direction opposite to the first. In the accompanying diagram (Plate X.,fig.5) Ihave attempted to restore the beds of the three formations to their positions at the time the Lower Silurian rocks were in their original horizontal position. It will be observed that then the Cambrian rocks had a dip westward, while the original denuded surface of the Laurentian schists sloped at a smaller angle in the same direction.* Upon this horizontality of the Cambrian beds depends in a large measure the peculiarities of the west Highland scenery, and it is doubtful if a stranger series of events in stratigraphical geology is to be found in any other part of the world.t Do Laurentian Rocks occur in the North or West of Ireland? All that one can say at this moment is, that the district lying north of Galway Bay in Connemara, Belmullet in Mayo, and parts of north- west Donegal contain beds of gneiss similar in appearance and composition to those which constitute the Laurentian beds of Sutherlandshire, and that these beds stand in some sort of rela- tionship to the recognized Lower Silurian metamorphic beds consisting of quartzites, limestones and schists. But until the Highlands of Donegal have been thoroughly explored by the officers of the Geological Survey, and the relations of the beds clearly established, no positive answer can be made to the above question, the Cambrian beds being (as far as we know) unrepresented. * From this diagram, which was made at Quenaig (see Plate XI., fig 9), not being drawn strictly to scale, I cannot be certain that the slope of the Laurentian floor is correct. + The peculiarities of this district have been described by Macculloch, Hugh Miller, Murchison, Ramsay, Geikie, and others. { The author proposes to make a preliminary examination of the Donegal Highlands during the ensuing summer with a view to determine the question here raised. On the Geological Structure of the Highlands of Scotland. 45 REFERENCE TO PLATES. Puate IX. Plate IX. Fig. 1. This is a drawing of “The Stack,” which, with its neighbours Coul Beg and Coul More, consists of nearly horizontal beds of. Cambrian sandstone and conglomerate, resting on a floor of Laurentian schist and gneiss. The position of this isolated mass is iniand from Lough Enard in Cromarty. Plate IX. Fig. 2. Represents the grand escarpment of Ben- more Coygeagh, in Cromarty, also consisting of hori- zontal beds of Cambrian sandstone, breaking off in precipices towards the south and west. The rocks of the foreground are of the same formation, and have an eastward dip. ‘The view is taken from the shore of an inlet from Loch Broom, looking north. Plate IX. Fig. 3. Represents the great buttress of Cambrian sandstone, in nearly horizontal layers, along which Quenaig ends off towards the north. From the base, the Laurentian floor from which the sandstone beds rise, stretches away northwards and westwards in a rough boulder-strewn tract to theshores of the A tlantic and the dark inlet of Kylesku. The manner in which the lower quartzite of the Silurian series stretches over the denuded edges of the Cambrian sandstones is represented in section, Plate XI., Fig. 9. PLATE X. Plate X. Fig. 4. Ben Stack in Sutherlandshire, seen from the entrance to Loch Inchard. This is a remarkably symmetrical cone of Laurentian hornblende schist, rising 2,364 feet above the Atlantic. The bedding, as also the system of joint planes by which the rock is traversed, are clearly visible, and their relationship to the outline of the cone will be recognised at a glance. The shores of Loch Inchard are composed of the red gneissose beds underlying those of Ben Stack. Plate X. Fig. 5. This is a diagram to illustrate the point to which I have drawn attention (p. 11), that at the time the Lower Silurian beds (s. 1) were being deposited ina nearly horizontal position, the Cambrian sand- stone (c.) of the district around Loch Assynt must have had a westerly dip. Upon the upheaval of the former, and on its assuming an easterly dip, the Cambrian beds were placed in their present position of approximate horizontality. 46 Scientific Proceedings, Royal Dublin Society. Plate X. Fig. 6. Is a section, drawn to scale, of the deep gorge ‘or cafion of Braemore, at the head of Loch Broom. The nature of this remarkable river-channel has already been sufficiently described. Plate X. Fig. 7. The section at the Bridge of Ault Corry, near Ullapool, in which the following beds in des- cending order are seen—all of the Lower Silurian series :— S. 5.—Hard, massive, reddish pebbly grit at the base of the upper quartzite—6 feet thick. 8. 5'—Whitish quartzite in regular beds—4 fect thick. S. 4.Thin band of shale and flags. S. 3.—Limestone in several beds with bands of shale—6 to 10 feet. 8. 2.—Grayish sandy shale with fucoid markings. S. 1._Upper beds of lower quartzite. General dip, E.S.H. at 5 to 6 degrees. Puate XI. Plate XI. Fig. 8. Section taken across Ben Stack and Ben Arkle. The former 2,364 feet, the latter 2,576 feet in eleva- tion ; direction about W. to H. Ben Stack, as already stated, is formed of dark horn- blendic schists, &c., of Laurentian age (L), penetrated by granite or pegmatite veins.. The Cambrian sand- stone being here absent, the Laurentian beds are immediately overlaid by the lower quartzite (s. 1) of the Lower Silurian series, forming the escarpment of Ben Arkle; this is followed by ferruginous sandy shales, with fucoids (s. 2), then by the Assynt lime- stone (s. 3), the glossy slates and flagstones (s. 4), the upper quartzite (s. 5), and finally by the micaceous schists of the interior (s. 6), at the margin of which the section ends. Plate XI. Fig. 9. Section drawn across Quenaig, 2,240 feet, and Ben More in Assynt, 3,281 feet, and passing a short distance to the north of Inchnadamff. This shows the basement hornblendic schists of Laurentian age (LL), overlaid by Cambrian sandstone and conglomerate (C), the beds of which are truncated along the eastern side of Quenaig by the lower quartzite of the Lower Silurian series. The succeeding beds are lettered and numbered as in the preceding section. [ 47 ] VII.—CORK ROCKS, sy G. H. KINAHAN, w.r.1a., é&c. | [Read, December 20th, 1880.] When describing the Cork Rocks in the fourth chapter of the “Geology of Ireland,” I pointed out that the Carboniferous rocks north of an irregular line drawn from Kenmare, county Kerry, to Passage West, Cork Harbour, have different relations to the underlying “ Glengariff Grits” (Jukes) from those that are tound to exist between the “ Carboniferous Slate” and the “ Glengariff Grits” (Jukes) south of this line; for while in the latter case there is a continuous sequence between the two, north of the line a similar sequence has nowhere been found. On the north side of this line the proximity of the Carboniferous Limestone to the “ Glengariff Grits” (Jukes) was pointed out by Griffith, Jukes, and their assistants, while the recent researches of Mr. M‘Henry seem to prove that there is an undoubted unconform- ability between the older and newer strata. He has not, however, brought forward any evidence which proves an unconformability between the Carboniferous Slate of S. W. Cork and the “ Glengariff Grits” (Jukes). On the contrary, all his work would seem to prove that Griffith and Jukes were right in stating that there was no unconformability or hiatus between these two groups of strata. The reason for the unconformability between the Carboniferous rocks north of the previously mentioned line and the “ Glengariff Grits” (Jukes) is a subject which as yet has not been properly considered or investigated, at first the problem may appear com- plicated, but if similar phenomena in action at the present day in different places are studied, the difficulty in a great meagure disappears. In north Europe, Scandinavia divides the Baltic from the seas to the westward. ast of Scandinavia the sea bottom for a long period has been continually rising and sinking, while west of Scandinavia the sea bottom has been comparatively stationary. Consequently in the first area the different accumulations ought 48 Scientific Proceedings, Royal Dublin Society. to be more or less unconformable to one another, while in the latter all the strata should form a continuous sequence, and in the straits connecting the two sea areas, various complications partaking of the nature of the two different systems of accumu- lations might be represented. | Let it be supposed that a similar state of things to that now going on in the Scandinavian seas gradually had been in existence in the area now represented by Cork and the adjoining portions of Kerry and Waterford. Furst, the rocks now represented by those called by Jukes “Glengariff Grits,”* were accumulated over a large area. Second, along an irregular line from Dingle Bay to Kenmare, and thence to and beyond West Passage, Cork, a mass of country began to rise, and in connexion with it a spur of country extend- ing from this line at Mangerton eastward for some distance. Third, in the area southward of the rising tract last mentioned the eround was stationary or gradually sinking so as to allow successive strata to accumulate on it; while northward of the rising ground, the land had already been rising before the accumulation of any new strata. Fowrth, south of the irregular line the accumulations formed a continuous sequence, while northward of it including | the tracts north and south of the spur of land extending east- ward from Mangerton, the newer accumulations would lie more or less unconformably on the older. Fifth, east of about the longitude, of Cork, at the hinge line where the elevation adjoined the depression, there would be considerable complica- tions, the accumulation of the two types being mixed and dove- tailing into one another. If the above suggestions are correct, northward of the line of rise, the newer rocks of the central Ireland Carboniferous type, ought to lie unconformably on the older in the following localities, viz.,in the vicinity of Dingle Bay, at Killarney lakes, in the valley of the Flesk and Blackwater, at Kenmare, and in the valley of the Lee at Macroom, Coachford, Innishcarra, Blarney, and Passage West. The localities just mentioned, beginning to the northward, give the following :—In the promontory of Dingle the Upper or * It is necessary, for the sake of distinction, to connect Jukes’ name with this group of rocks, as Prof. Hull has given a nearly similar name to a more extensive group of which these rocks form but a part. Cork Rocks. 49 Carboniferous Old Red Sandstone les unconformably on the “Dingle beds,” the representative of a portion of Jukes’ “Glen- gariff Grits ;” while south of Dingle Bay, between Doulus Head and Killarney, there seems to be a somewhat similar unconforma- bility. In the neighbourhood of the middle lake of Killarney, in Glenflesk, and in the western portion of the Blackwater Valley, there is the great fault with a downthrow to the northward, but at the same time the Carboniferous rocks appear to be much nearer to the “Glengariff Grits” (Jukes) than they ought to be, if a regular sequence intervened between them; as, however, in the places where the sections are best exposed, the rocks evidently lie in inverted folds, nothing positive can be said as to the original relations of one group to the other. Further south- ward at Kenmare, and in the valley of the Lee, the relations between the Carboniferous Limestone, and the red and bright coloured older arenaceous and argillaceous rocks are very remark- able. As pointed out in the Geological Survey Memoirs and elsewhere, some miles westward of Kenmare in the neighbourhood of Sneem and Kilmackilloge, respectively north and south of Kenmare River, there are the “Carboniferous Slate,” the upper member of the sequence that extends downwards conformably into the “Glengariff Grits” (Jukes); but in the neighbourhood of Kenmare there is a conspicuous difference as red rocks, not to be found to the westward, or in the country to the 8. W., suddenly make their appearance, and associated with them are the rocks ealled Lower Limestone Shale, and the Lower Limestone; these red rocks appear to lie conformably on the “Glengariff Grits” (Jukes), but it is questionable whether the Lower Limestone Shale and the Limestone lie conformably on them or not. Further eastward in the valley of the Lee, at Macroom, Coachford, Innishearra and other places, the Carboniferous Limestone seems to lie nearly directly on the “ Glengariff Grits” (Jukes). In these different places “ Lower Limestone Shale” is associated with the Limestone, and in the maps it is generally represented as en- circling the different masses of the latter, this, however, seems to me to be improbable, as the Lower Limestone Shale is essentially a littoral accumulation and consequently must have only accu- mulated in those portions of the different areas where the con- Scien. Proc., R.D.S. Vou. m., Pt, 11. i 50 Scientific Proceedings, Royal Dublin Society. ditions were favourable for its being deposited, such as shallow bogs and the like. In connexion with these outliers of Carboni- ferous Limestone “Lower Limestone Shale,” 2m situ, has been observed in places, but in others no trace of it can be seen, and apparently it is altogether absent, the limestone lying directly on the older rocks. The rocks in the valley of the Lee, would seem to suggest a solution of the difficulty at present felt in reference to the differ- ence in the arrangement of the rocks north and south of the pre- viously mentioned irregular line between Kenmare and Passage West (Cork Harbour), as hereabout the newer rocks evidently were deposited in a valley margined with high cliffs of “ Glen- garitf Grits” (Jukes); but the rocks in the Kenmare valley are so peculiar that before offering an opinion on them they would require a very careful examination. In the vicinity of Cork Harbour, is the locality of the hinge line, between the depression and elevation where the rocks of the Central Ireland type, and of the Cork type, meet and inter- mingle. Consequently from Cork Harbour eastward to the sea near Dungarvan, the rocks in the sections may he of either types, or of the two types mixed up together, while in places they seem to lie unconformably on the “ Glengariff Grits ” (Jukes). The “Glengarit Grits” also seem to be changing eastward, and T suspect that the rocks of the Commeragh mountains (conglo- merates, &c.), although lithologically different, yet eventually will be found to be the littoral accumulations of the “Glengariff Grits” (Jukes). rota VIIL—ON THE PHYSICAL UNITS OF NATURE,* psy G. JOHNSTONE STONEY, D.sc., F.R.8., SECRETARY TO THE SOCIETY. [Read, February 16th, 1881.] When mathematicians apply the sciences of measurement to the investigation of Nature, they find it convenient to select such units of the several kinds of quantity with which they have to deal as will get rid of any coefficients in their equations which it is possible in this way to avoid. Every advance in our knowledge of Nature enables us to see more distinctly that it would contribute to our further progress if we could effect this simplification not only with reference to certain classes of phenomena, but throughout the whole domain of Nature. Hitherto the practice of mathematicians has been governed by the demands of the science of mechanics, in the greater part (though not in the whole), of which science it is possible to derive the units of all the other kinds of quantity from any three which may be chosen. A system built in this way upon a foundation which is arbitrarily assumed is necessarily an artificial system. The units which are usually selected as the fundamental units of a series of arbitrary systematic measures, are— The metre for lengthine, or unit of length, The gramme for massine, or unit of mass, and The solar second for timine, or unit of time. These three, and all the units which may be derived from them may be called the metric series of units, and in this investigation they will be represented by small letters. Thus— The fundamental metric units being, l,, the metre, the metric lengthine, or unit of length. t,, the solar second, the metric timine, or unit of time. m,, the gramme, the metric massine, or unit of mass. some of the derived units will be, v, the metric velocitine, or, unit of velocity, which is a velocity of one metre per second. * This paper was read before section A., of the British Association at the Belfast Meeting in 1874. + Since this paper was written the centimetre has been suggested as a unit of length, and has been largely made use of. 52 Scientific Proceedings, Royal Dublin Society. fj the metric forcine, or unit of force, which is the Hyper- decigramme,* this being the force which if it acted in a fixed direction on a mass of one gramme for a second would in that time change its velocity by one metre per second. mm! #,, the metric unit of the coefficient in the expression » 7a for the gravitation of two masses towards one another. This unit is the coefficient which should be used if each gramme mass attracted other ponderable matter at a metre distance with such intensity as would impress on it an acceleration towards the attracting gramme of one metre per second per second. é,. the electromagnetic electrine, or the electromagnetic unit quantity of electricity in the metric series, is that quantity of each of the two kinds of electricity which must be discharged every second in opposite directions along a wire, in order to maintain in it the metric unit current ; this currentine or unit current being defined as the current which must exist in a wire a metre long in order that it may exert a force of a Hyper-deci- gramme on ponderable matter at a metre distance charged with a unit of magnetism; and the unit charge of magnetism of either kind being defined as that quantity which acting on ponderable matter at a metre distance, charged with an equal quantity of magnetism, exerts on it the unit force, that is one Hyper-deci- gramme. * The hyper-decigramme means the gravitation or downward force towards the earth of a mass which exceeds a decigramme in the ratio of ; where g is the acceleration of gravity measured in metres per second per second. The appropriateness of the term : . : . 10 hyper-decigramme arises from the circumstance that the coefficient — everywhere exceeds unity, whether within the earth, outside it, or on its surface; and the convenience of the term arises from the circumstance that on the earth's surface the coefficient nowhere exceeds unity by more than a small fraction, so that the hyper-decigramme is a force which but little differs in value from that gravitation or weight of a decigramme with which we, inhabitants of the earth, have become familiar; so that the name suggests to us the amount of the force. Gravitation is the downward force and gravity is the downward acceleration towards the earth as observed. They are chiefly due to the attraction of the earth, and in a small degree, when the observation is made on or within the earth, to the earth’s rotation. Tbis is the meaning of the word gravity as it is used by the classical writers on mechanics, (see Pouillet’s Mécanique, passim), and the practice of some modern writers, who use this term to designate a force instead of an acceleration, is to be deprecated. On the Physical Units of Nature. 53 It is easy to ascertain the relation of this metric electrine to the B.A. (British Association) standards for electrical measure- ment, which are those most in use. The B.A. units are electro- magnetic units based on the following fundamental units—the second for unit of time, the metre-seven (the quadrant of the earth, or 10’ metres) for unit of length, and the eleventh-gramme ‘(or gramme divided by 10") for unit of mass. These were so chosen as to furnish a connected body of systematic units with such values that the practical electrician could conveniently use them. Now the ‘dimension’ of electromagnetic quantity of elec- tricity is [VIM] (see B.A. Report for 1863, p. 159).* Hence and from the foregoing values of the lengthine and massine of the B.A. series— 7 é, : One Ampére = |: ye 104 Therefore e, = 100 Ampéres. The term Ampére is here used to designate the B.A. unit of quantity, corresponding to the Ohm (the B.A. electromagnetic unit of resistance), the Volt (the corresponding unit of electro- motive force), the Weber (unit of current), and the Farad (unit of capacity). The electrostatic units of the B.A. series might with great advantage be called the static-Ampeére, static-Ohm, static- Volt, and static-Farad. Units like the above, whether of the metric or of the B.A series, of which three are fundamental and all others derived from them in such a way as will exclude unnecessary coefficients from our equations, are called systematic units. In forming the existing artificial series of systematic units it has been usual to regard the units of length, time and mass as fundamental and the rest as derived, but there is nothing to prevent our regarding any three independent members of the series as fundamental and derwoung the others from them. It is the aim of the present paper to point out that Nature presents us with three such units; and that if we take these as our fundamental units, instead of choos- ing them arbitrarily, we shall bring our quantitative expressions into a more convenient, and doubtless into a more intimate, rela- tion with Nature as it actually exists. I will then approximate * This follows. at once from the fundamental equations of electromagnetism, viz. :— KE: ° Fo 7a? E Crs 2 eee Phd pe 54 Scientific Proceedings, Royal Dublin Society. to the values of the units of length, time, and mass, belonging to this which is a truly natural series of physical units. For such a purpose we must select phenomena that prevail throughout the whole of Nature, and are not specially associated with individual bodies. The first of Nature’s quantities of abso- lute magnitude to which I will invite attention is that remark- able velocity of an absolute amount, independent of the units in which it is measured, which connects all systematic electrostatic units with the electromagnetic units of the same series. I shall call this velocity V,. If it were taken as our unit velocity we should at one stroke have an immense simplification introduced into our treatment of the whole range of electric phenomena, and probably into our study of light and heat. Again Nature presents us with one particular coefficient of gravitation, of an absolute amount independent of the units in which it is measured, and which appears to extend to ponderable matter of every description throughout the whole material uni- verse. This coefficient I shall call G, If we were to take this as our unit of coefficients of attraction, it is presumable that we might thereby lay the foundation for detecting wherein lies the connection which we cannot but suspect between this most won- derful property common to all ponderable matter, and the other phenomena of nature. And, finally, Nature presents us in the phenomenon of electro- lysis, with a single definite quantity of electricity which is inde- pendent of the particular bodies acted on. To make this clear I shall express “Faraday’s Law” in the following terms which, as I shall show, will give it precision, viz.:—For each chemical bond which 1s ruptured within an electrolyte, a certain quantity of electricity traverses the electrolyte, which is the same in all cases. This definite quantity of electricity I shall call E,. If we make this our unit quantity of electricity, we shall probably have made a very important step in our study of molecular phenomena. Hence we have very good reason to suppose that in Vj, G,, and E,, we have three of a series of systematic units that in an eminent sense are the units of Nature, and stand in an intimate relation with the work which goes on in her mighty laboratory. The approximate values of V,; and G, are known, and I will presently endeavour to evaluate H,, V, has been variously de- On the Physical Units of Nature. 55 termined by experiment as 3:10 metre-eights per second, 2'82 metre-eights per second, 2°88 metre-eights per second and may be assumed to be not far from 3 metre-eights per second. Accordingly we may put— V,=3 VIII. metres per second......... (DE Similarly, if we use the value given by Sir John Herschel for the mass of the earth, viz., 5942°X VIII* english tons, which = XXIV. grammes, we find that— i stall = 3 ee (2); To determine E,, we must first establish a relation between the gaseous molecule of a body, and what in chemistry is called its atom. To do this, let us start with the definition that a chenucal atom is the smallest mass of each kind of ponderable matter that has been found to enter or leave a combination. Now from Boyle and Charles's law we know that in all gases there are approximately the same number of molecules per litre, if they be taken at the same temperature and pressure; from ex- periments on diffusion we know that these molecules are alike in mass; and from the phenomena of chemistry we know that they are alike in other respects. Let, then, a litre of hydrogen and a litre of chlorine be mixed and exploded, and let the resulting hydrochloric acid gas be brought back to the original temperature and pressure. It ig then found to measure two litres. Hence, if N be the number of molecules in a litre of gas at that temperature and pressure, we learn by this experiment that N molecules of hydrogen, and N molecules of chlorine produce 2N molecules of hydrochloric acid. Hence, and since the molecules within each gas are alike, each _ molecule of hydrochloric acid must contain the quantity of hydro- gen represented by a semi-molecule of hydrogen gas, and the quantity of chlorine represented by a semi-molecule of chlorine gas. We are thus introduced to the semi-molecule of each of these gases as a quantity which enters into combination ; and as no. other experiments suggest’ a smaller quantity, the semi- G * The Roman figures following a number stand for cyphers. Thus 3.VIII signifies 3 xX 108, and 5942 XVIII stands for eighteen cyphers following 5942. Where no number precedes the Roman figures, the number 1 is to be understood, so that in XXIV. grammes, the Roman figures stand for 1 followed by 24 cyphers, in other words for 1074, a number which may conveniently be called the Unit-twenty-four. 56 Scientific Proceedings, Royal Dublin Socrety. molecule of hydrogen, and the semi-molecule of chlorine, are, in the present state of science, to be accepted as the chemical atoms of these substances. Hence we may write— H, the atom of hydrogen = the semi-gaseous molecule of hydrogen, and Cl, the atom of chlorine = the semi-gaseous molecule of chlorine, and we see that HCl is the proper formula for hydrochloric acid. We may further deduce from the observed densities of the gases that the masses of the atoms of hydrogen, chlorine, and Hydrochloric acid are to one another in the ratio of 1, 355, 363. Another experiment shows us that a litre of steam may be resolved into a litre of hydrogen and half a litre of oxygen at the same temperature and pressure ; in other words, that N molecules of steam are formed of N molecules of hydrogen and molecules of oxygen. Hence each molecule of steam contains a whole molecule (or two atoms), of hydrogen, and a semi-molecule of oxygen. We thus arrive at the semi-molecule of oxygen as a quantity that enters into combination, and as all other experiments with oxygen concur, the semi-molecule of oxygen is to be received as its atom, and H,O is the proper formula for what is both the gaseous molecule and the atom of water. From the densities we may also deduce that sixteen is the atomic weight of oxygen, i.e. that an atom of oxygen is sixteen times as heavy as an atom of hydrogen. Similarly from the densities of ammonia and of its constituents we learn that the atom of nitrogen is the semi-molecule and that the mass of its atom is 14 times that of hydrogen. It must not be assumed that the atom is always the semi- molecule. In some cases it is found to be the entire molecule, and in other cases the quarter molecule. Thus the mercuric compounds of mercury give vapours of the same bulk as the vapour of the mercury they contain, and indicate an atom of mercury equal to its molecule, while the other volatile compounds of mercury contain more than one molecule of mercury in each molecule of the compound, and therefore do not disturb this conclusion. Again, a litre of phosphuretted hydrogen yields a quarter of a litre of the vapour of phosphorus and one and a-half On the Physical Units of Natwre. 57 litres of hydrogen, indicating that the quarter molecule of phosphorus is its atom. The same is true of arsenic. A similar treatment of marsh gas furnishes twelve as the mass of an atom of carbon, although carbon is not sufficiently volatile to enable us to ascertain the relation of its atom to itsgaseous molecule. By extending this method to all the available cases, we may deduce from the fundamental properties of gases a demonstration of a great part of the modern table of atomic weights, and of the doctrine of atomicity which depends on it. Thus, two bonds* are necessary to connect the group SO, with the two atoms of hydrogen that are united to it in sulphuric acid, while one bond is sufficient to join the atoms of hydrogen and chlorine in an atom of hydrochloric acid and so in other cases. Now the whole of the quantitative facts of electrolysis may be summed up in the statement that A DEFINITE QUANTITY OF ELECTRICITY TRAVERSES THE SOLUTION FOR EACH BOND THAT IS SEPARATED. Thus, if a current pass in succession through vessels containing solutions of sulphuric acid and hydrochloric acid, two atoms of hydrochloric acid will be decomposed in the one vessel for each atom of sulphuric acid that is decomposed in the other, but the nwmber of bonds separated will be the same in both vessels. It is the quantity of electricity that passes per bond separated that we have now to determine, and this may be done approximately in the following manner. Several inquiries (see Prof. J. Loschmidt ‘Zur Grésse der Luftmolecule’ Academy of Vienna, Oct., 1865; G. Johnstone Stoney on ‘The Internal Motions of Gases’ Phil. Mag. August, 1868; and Sir William Thomson on ‘The Size of Atoms’ Natwre, March 31, 1870), have led up to the conclusion that thé number of molecules in each cubic millimetre of a gas at atmospheric temperatures and pressures is somewhere about a unit-eighteen (10). Hence the number of molecules in a litre will be about a unit-XXIV. Now, a litre of hydrogen at atmospheric pressures, and temperatures weighs, roughly speaking, a decigramme. Hence the mass of each molecule of hydrogen is a quantity of the same order as a * The word bond is here used of the connexions between atoms when they enter into combination. When we employ the term in this sense, which seems its proper signification, bonds are to be distinguished from the hands or feelers which each atom has, and which by grappling with the hands or feelers of other atoms establish bonds between them. Scren. Proc., R.D.S. Vou. 111., PT. 11. EF iZ- Scientific Proceedings, Royal Dublin Society. decigramme divided by a unit-X XIV, ve. a XXVth gramme. The chemical atom is half of this. Hence the mass of a chemical atom of hydrogen may be taken to be somewhere about half a twenty- fifth-gramme. There is no advantage in retaining the coefficient half in an estimate in which we are not even sure that we have assigned the correct power of 10, and I will therefore, for the sake of simplicity, take the XXVth gramme as being such an approach as we can attempt to the value of the mass of an atom of hydrogen. _ Now ic has been ascertained by experiment that for every Ampére of electricity that passes ninety-two sixthgrammes, 1... ninety-two millionths of a gramme of water, are decomposed (see B.A. Report 1863, p. 160). This water is the result of a secondary action in the voltameter, but that does not effect the present inquiry. Ninety-two VIth grammes of water contain about one Vth gramme of hydrogen, which is therefore the quantity evolved. The metric unit of electricity e, 1s 100 Amperes, and will there- fore set free 100 Vth grammes of hydrogen, 7.¢., one milligramme, Now it appears, from the last paragraph, that this quantity of 2 ROXERY, : : hydrogen contains a atoms, v.¢., XXII. atoms. And as there is a bond ruptured for each atom of hydrogen set free, this is also the number of bonds broken. In other words the quantity of electricity corresponding to each chemical bond separated is 1 E, i XXII (Gy BoadousodcoudooudcoonsaqKd0 (3). Collecting our numerical results they are V, = 3. VIII, metres per second....(1). ae fi G, = SCT Coober eso reer csoee roGKee (2) @; K, = NOGIICMEN se ae ae (3) 1 = xx Amperes Bd set rec aees ge (4). We have thus obtained approximate values in known measures for the three great fundamental units offered to us by Nature, upon which may be built an entire series of physical units deserving of the title of a truly Natural Series of Physical Units. It now only remains to deduce the units of length, time, and mass belonging to this series. For this purpose we may use On the Physical Unats of Nature. 59 dimensional equations. Remembering, as is well known, that the dimension of a unit of velocity is lel; that of a unit of coefficients 3 of attraction [sr | and that of an electromagnetic unit of quantity [VLM], we find from equations (1), (2), and (3) respec- tively, that L, dy ioe i Pi Shh 4), Ts nee - L3 i, 4 MT? = B mA, ook (5). ENTE CN Aig ee (6). im which L,, M,, and T, are used to designate the units of length, mass, and time in the ‘ Natural’ series, while /,, ™,, and t, repre- sent the corresponding units in the metric series, viz., the metre, gramme, andsecond. A, B, and C also are used, for brevity, to stand for the numerical coefficients of equations (1), (2), and (8), Dae eh De Canies Re one Solving equations (4), (5), and (6), we find viz. :—For the numbers 3 VIII CvB ‘ i ee (7). CVB iM — Aa t, e@oceceece (8). CA M, = VB M0 ooonocone (9). Substituting for A and B their numerical values, and writing metre, second, and gramme, for J,, ¢,, m,, 1 1 L, = C 3/15 XTv’ metres. Lier 1 T, =C 3 BVip XX’ seconds. Mh ee SOAS Sany grammes. or, more simply, (inasmuch as 10 is sufficiently near to 8715 to be used instead of it im an approximation like the present) 1 L, = C Xy metres... (10). 1 Il TT = C 3 XXIII SCCONGSH ese eae (11). M9 CeXGV orammiesi ay ease (12). In obtaining these equations we have only used the numerical values of V, and G,, which are known to a satisfactory degree of 60 Scientific Proceedings, Royal Dublin Society. approximation, and if we go no farther there will remain but one arbitrary member in the entire of the resulting series of systema- tic physical units. If we also introduce the numerical value found above for C which depends on H, and is less accurately known, we obtain the following actual values for these units of Nature. 1 L, = XXXVII of a metre......... (13). Leena T, = 3 XLV Olarsecond: 2) 0 Rey (14). 1 M, = Vil OH Ay UPMANTINEs go mncnca9s (15). or, in other words— The natural unit of length approaches in value to the thirty seventh-metre, (7.¢., the metre divided by 10%). The natural unit of time approaches in value to one-third of the forty fifth-second, (7.¢, one-third of the second of time divided by 10”); and The natural unit of mass approaches to the seventh-gramme, (i.e., the gramme divided by 10”). This appears the best attempt we can yet make to determine these remarkable units. In the series to which they belong all the electrostatic units will be identical with the corresponding electromagnetic units ; all the forces of Nature that are known to obey the law of the inverse square, whether they arise from gravi- tation, electricity, or magnetism will be expressed without coefficients; and the chemical bond which seems to be the unit of concrete Nature is brought into its proper relation to physics. Postscript.—Many persons find it difficult to conceive of G, as a unit. G, may be avoided and M, substituted for it, if M, be defined as a mass such that it attracts an equal mass at a distance with the same force with which two units of electricity as defined on p. 56 (7.e. each equal to E,), would, if placed at the same distance asunder, act on each other, The three fundamental units of the Natural System will then be V,, H,, and M,, from which all others are to be derived. This M, is the same as the M, of equation (15). PUBLICATIONS OF THE ROYAL DUBLIN SOCIETY. TRANSACTIONS : Quarto, in parts, stitched. - Vol. I. (new series). (Recently published.) i Part 10.—On the Possibility of Originating Wave Dishinbanesde in: ae the Ether by means of Electric Forces. -By G. F. Frrzcrrap, M. Ay F.T.C.D. (February, 1880.) yj Part 11.—On the Relations of the’Carboniferous, Devonian, and Upper Silurian Rocks of the South of Ireland to those of North Devon. By Epwarp Hutt, M.A., LL.D., F.R.S., Director of the Geological Survey of Ireland, and Professor of Geology, Royal College of Science, Dublin. With Plates IV. and V., and Woodcuts. (May, 1880.) Ratt, Part 12.—Physical Observations of Mars, 1879-80. By C. E. Burton, B.A., M.R.LA., FLR.A.S. With Plates VIL, VIL, and VIII. (June, 1880.) Part 13.—On the Possibility of Originating Wave Disrabaeees in the Ether by Means of Electric Forces. Part 2. By Gnorce Francis Fitzerrap, M.A., F.T.C.D. (November, 1880.) Part 14.-Explorations in the Bone Cave of Ballynamintra, near __ Cappagh, County Waterford. By A. Leira Apams, M.B., LL.D., — E.R.S., F.G.S. G. H. Kinanan, M.R.J.A. and R. J. UssHer. Plates 1X. to XIV. (April, 1881.) at ie: Vol. II. (new series). Part 1.—Observations of Nebule and Clusters of Stars made with the Six-foot and Three-foot Reflectors at Birr Castle, from the year 1848 up to about the year 1878. Nos.1 and 2. By the Right Hon. the Earl of Rossz, D.C.L. With Plates I. to IV. (August, 1879.) Part 2—Do. do. No.3. With Plates V. and VI. (June, 1880.) ia ae PROCEEDINGS: 8v0., in parts, stitched. Vol. IT. new series, ) (Recently pablished: ) Part 6.—Pages 417 to 550. (July, 1880.) Part 7.—Pages 551 to 634. With Title. (November, 1880.) _ Vol. IIT. (new series). ‘ Part 1.—Pages | to 32. (January, 1881.) Part 2.—Pages 33 to 60. (April, 1881.) * THE SCIENTIFIC PROCHEDINGS OF THE ROYAL DUBLIN, SOCIETY. roe i (Ney Summ). JULY, 1881. io Bin Wm: - CONTENTS. a: IX. On Birds observed in Amelia a Virginia. By Prrcy ee 4 * _ &. Frexe, 4 61 X. Description of the ee “a Brvdiloee Saploged in Photographing Ultra-Violet Spectra. By W. N. Harruixy, F.R.S.E., &c., Professor of Chemistry, Royal es of Science, Dawiin: Plates 12,13, 14, and 15, . 93 XI. On the Thicknesses of the Irish Beaded Rocks. By G. H. Kinanan, M.R.1A., President a Geological Spee Ireland. Plates 7 and 8, : 108 _ XII. Anniversary Address to the Royal Gealoaiel iGocicey oF Ireland. By G. H. Kivaway, M.R.LA., “President, :.* 109 XIII. On the ee of the Milk of Boek: two Cows. By ig Cuartes A. Cameron, M.D., Fellow and Professor of Chemistry, Royal College of Sur ceons, Ireland, ‘ .- 125. XIV. On the recent remarkable Subsidences of the Ground in the Salt Districts of Cheshire. By Professor Enwarp Hurt, LL.D., F.R.S., Director of the Geological oe of Treland, . : 133 XY. On the Identification of penta Bacalttes meniened in my Paper on the Diamonds of India. By V. Baun,M.A.,F.G.S., 139 XVI. Concluding Note on the Manufacture of Paper from Aoi cerulea. By W. Suiru, C.E., 5 141 XVII. On the Origin and probable Sinncinre of the Dome Moun. tains of Central France. By Epwarp Hutz, B.A., eV TAS XVIII. Photographic Spectrum of Comet. By eee Hugues mae DCL; ER:S 3 .cac., ; : A i Rae Ola: (os The Authors alone are responsible jor all opinicns expressed in their c mein OE 4 19h] @, tonal Museus ; DUBLIN: - PUBLISHED BY THE ROYAL DUBLIN SOCIETY. PRINTED BY ALEX. THOM & OO0., 87, 88, & 89, ABBEY-STREET, THE QUEEN'S PRINTING OFFICE. FOR HER MAJESTY’S STATIONERY OFFICE. ae es 1881. “Bap al Dublin Society. FOUNDED, A.D. 1731. INCORPORATED, 1749. Evening Scientific Meetings. The Evening Scientific Meetings of the Society and of the adsocihell bodies (the Royal Geological Society of Ireland and the Dublin Scientific Club) are held in Leinster House on the third Monday in each mcnth during the Session. The hour of meeting is 8 o’clock, p.m. The bustaees » is conducted. in the undermenticned sections. Section I.—Puysicat anp EXPERIMENTAL ScIENCEs. Secretary to the Section, R. J. Moss, ¥.c.s. Section IT.—Narurat Scrences (including Geology ae Physical Geography). Secretary to the Section, R. M‘Nap, wp. Section ILI.—Scrence Apriiuy to THE UsErun ARTs AND INDUSTRIES. Secretary to the Section, Howarn GRUBB, M.E., T.C.D. Authors desiring to read papers before any of the sections of” the Society are requested to forward their communications to the Registrar of the Royal Dublin Society (Mr. R. J. Moss), or to one of the Sectional Secretaries, at least ten days prior to each evening meeting, as no paper can be set down for reading until examined and approved by the Science Committee. The copyright of all papers read becomes the property of the Society, and such as are considered suitable for the purpose will be printed with _ the least possible delay. Authors are requested to hand in their MS. in a complete form and ready for transmission to the printer. [ 61 ] IxX.—ON BIRDS OBSERVED IN AMELIA COUNTY, VIRGINIA, sy PERCY E. FREKE. [ Read, February 21st, 1881.] I HAVE lived altogether for six years in Virginia, about thirty miles south of Richmond, the capital, and during that time I have carefully observed and noted the habits of the resident and migratory birds of the district, verifying my observations, as far as possible, by securing specimens and preserving skins. The fact with which I have been most struck is the apparent total absence of so many species, which, from their known range, I consider I ought to have met with, and the rarity of others which I ex- pected to have found more numerous. The period during which I have resided there, and the time and pains which I have given to the subject, preclude the possibility of a species frequenting in any numbers the district in which I have been working, without my being aware of it. Some birds, certainly, I have noticed which I have never been able to obtain, or to determine satisfac- torily, and which are therefore omitted here; but they are not many. The distance at which I lived from the sea, or from any large river, must account for the absence of the host of waders and swimming birds, which a residence near the coast would have added to my list; but still, as there were two small rivers with swamps and ponds in the vicinity, which I constantly and carefully searched, I think I was justified in expecting a larger number of species than appear in the following paper. I can only suppose that many species having a widely extended range, are yet within that range, but local in their distribution, and that the district in which I lived was not a very favoured one in this respect. To the study of migration I have given especial attention, noting first arrivals and last appearances. In autumn I wrote a list every evening of all the migratory birds I had observed during the day, and noted how one by one the different species disappeared. Many species become unusually numerous for a short time before their departure, being reinforced, no doubt, by the northern contingent on its way southward, Others, with which Virginia Scien. Proc, R.D.S. Vou m1, Pr. m1. G 62 Scientific Proceedings, Royal Dublin Society. seems to form about the limit of their northern range, band together in some numbers for a day or two, and then abruptly disappear, as our own swallows may often be observed to do at home. . . In migrating north the smaller birds generally arrive suddenly in some numbers, often in large flocks, which after a while scatter themselves over the country to breed, or wholly, or partially pass on to the north. At this time of the year fifty birds will probably be noticed for one that will be observed a few months later, although the bird population of the country is always pretty numerous. This is probably caused not only by the absolutely greater numbers which are present at the time, but also because they are much more conspicuous when collected together in flocks, or when the males, while seeking their mates, display themselves as much as possible ; whereas, later in the year, when they have commenced the duties of the summer, they are scattered in pairs over the country, and seek concealment for themselves and for their young. The trees and bushes too are then in full leaf, and their dense shade affords the forest-loving species an almost impene- trable screen. In travelling south again they generally come in small parties or families at first, then in numbers or in flocks, which may be met with everywhere for a while, and then disappear. Some, as the geese, appear in much larger flocks when going southward than when advancing to the north; whereas, with others, as the different species of Molothrus, Grackels, &c., the reverse is the ease. Some, as the gold-crests, that I have observed assembled in small family parties, a little earlier in the year, in Canada and the Northern states, seem to visit us singly, or at the most in pairs, and during some years I have observed species appearing by no means uncommon, which in other years were totally absent. Go into the pine woods late in the autumn and you may wall for half an hour without seemg anything of bird hfe; then you hear a note, and you see several little birds in the tree tops. Probably it was the Carolina tit that attracted your attention, for this restless little creature is generally the first to see you and give the alarm. If you remain still, you may perhaps see five — or six species of birds busily searching for insects, and flitting restlessly from tree to tree, passing and crossing each other, but all { On Birds observed in Amelia County, Virgonia. 63 tending in one direction. You will probably see the Carolina and the tufted tit, one or two of the smaller woodpeckers, the white- bellied nuthatch, perhaps the gold-crested wren, and one of the small warblers, generally Dendreca coronata. Busy as they are searching for insects, they all seem to keep together, and in a few minutes pass away; not one will remain, and the woods will be as silent as if there were no living thing for miles around. In an hour perhaps you may meet another little flock, acting just in the same way. In the spring you may see somewhat the same thing, but the flocks are smaller, and composed generally only of tits, and perhaps a couple of woodpeckers. At first I was under the impression that in autumn these little flocks were all moving southward, but longer experience has convinced me that this is not the case, but that their regular migrating movements are performed, in most instances, during the night, and that in the daytime they devote themselves to searching for food, ard move about the woods without any regard to the points of the compass, generally following the direction of the valleys or streams where veins of deciduous trees run through the forest of pines. T have also often noticed a sudden incursion of some species not generally abundant. The locality where they are observed will now be alive with them, quarrelling, chattering and fussing about looking for food, moving on their course being apparently the idea furthest from their thoughts; perhaps another day may be spent by them in the same way, at the same spot, and on the next not one will be found in the district. The migration southward seems to be performed more regularly and leisurely than when going north. In spring they will some- times, with favourable weather, pass through in a great hurry, the bob-o-links, for instance, seldom staying more than two days or three. In other years they will often hang about for a long time, and a spell of bad weather will sometimes drive them away from the district entirely, to reappear when it is over, when they remain in varying numbers, occasionally for weeks, and that with species not one of which stays all the summer. Partial migration, I think, also takes place to a very large extent, but is not so easily observed. For instance, the robins (Turdus migratorius), bluebirds, tits, and nuthatches, which we Soren. Proc., R.D.<. Vou. ut, Pr. m1. G2 64 Scientific Proceedings, Royal Dublin Society. see in winter, are not, I think, the same individuals which have remained and bred with us during the summer. The two former species migrate to a considerable extent during the daytime. In autumn I have constantly seen small flocks coming from the north. Like specks in the distance they come steadily on, the robins in little bands of from half a dozen to twenty; they light on a tree, and sit there apparently resting themselves for some time, then suddenly they al! start again and fly off straight, as far as the eye can follow them, to the south. I have often timed the robins by my watch, and generally find they remain for ten minutes or a little more, but sometimes they willstay for half an hour. The bluebirds come in fewer numbers—from one or two to half a dozen. They do not fly so far at once, and generally alight on the very top of some tall tree, where they often stay scarcely two minutes, though sometimes they will remain a long time, generally incessantly uttering their call note. Although I have noticed this form of migration in robins, yet I also observe that they, perhaps more than any other bird, are prone to appear suddenly in flocks in a particular locality, which they will frequent in great numbers for a few days, and then dis- appear, following what I believe to be the ordinary rule of migra- tion among small birds. Wild pigeons also migrate largely during the daytime ; in com- paratively small bands in spring, which often stop with us some time, but often in immense armies in autumn, which rarely halt. The males of some birds, especially the warblers, often arrive before the females, and are sometimes quite numerous for some days before a single female has been seen. This is, perhaps, most markedly the case with the black-and-white creeping warbler. _ Regularly every year, also, I have noticed that in the autumn migration southward, the localities frequented by some birds differ entirely from those which are sought by the same species when advancing northward in spring; this is notably the case with the pine warbler, as mentioned under the head of that species. Although scarcely more than one hundred miles from the Atlantic, I have never, during all the time I have been there, seen a single gull, or truly saltwater bird in the district of which I write, even after the worst and most stormy weather, nor at any season of the year. On Birds observed in Amelia County, Virginia. 65 In Virginia I have noticed especially the tameness and fami- liarity of many species during the breeding season, some of which at other times of the year, are comparatively wild and unap- proachable. This, I believe,is very commonly the case with birds generally, but I have never noticed it so markedly as I have there. TURDUS MIGRATORIUS (Linn.) American Robin.—A few may be seen all through the winter, but they arrive in large flocks from the south early in March, when they collect in great numbers on the tree tops, chattering and screaming. The earliest note I have of their arrival is the 2nd of March. This was in 1878. They scatter themselves over the open ground in search of food, hopping about with a remarkably upright carriage. They are very fond of the berries of the cedar, and on the edges of the woods these trees are often covered with them, swarming about among the branches, and devouring the berries as fast as they can, fluttering and chuckling all the time in a most fussy manner. As evening draws on, or at the sound of a gun, they collect in flocks on the tops of the highest trees. A few pairs remain with us all the summer and rear their young, but most of them pass on to the north. They generally choose as a site for their nest a low tree near a house, or some open spot, and I have never found them building in the woods, as some of the thrushes do. The i2th October is the earliest date at which I have seen the flocks returning from the north, and they continue to pass on southward for some time. Their chuckling note reminds one much of our own blackbird, and their song is rather good. TuRDUS PALLASE (Cabanis.) Hermit Thrush—This is a resident species, apparently not migrating eyen in the most partial manner; nor have I noticed it in any way more numerous at one season than another. It is a shy, retiring bird, and never seems to collect in flocks, but is met with singly or in pairs—generally the latter. It loves best the deep dark woods, where it builds its clay-lined nest in the fork of some cedar or dogwood bush, at the height of eight or ten feet from the ground, and there lays its blueeges. Itisrathera silent bird, gliding noiselessly through the trees, seldom rising to any height, and as evening comes on, frequently uttering its whistling note when it thinks itself unobserved ; but I once saw it singing 66 Scientific Proceedings, Royal Dublin Society. vigorously in the sunshine, on the topmost boughs of a tall tree in an exposed situation. | HARPORHYNCHUS RUFUS (Cabanis.) Brown Thrush.—This fine songster, whose note always reminds me of our own thrush, arrives in spring; but whether a few remain all the winter or not, I am not sure. J have seen it as early as the 18th March, with snow on the ground, and a cold north wind, in very wintry- looking weather, but they do not become common for a month later. One generally sees it flitting about near the ground, among thick bushes. The nests I have taken have always been in situations of this kind, in thick tangled places. Its life is pro- tected by law on account of its fine voice, but it has a very bad reputation for pulling up sprouting corn. It is in my opinion the best songster in Virginia, even the mocking bird cannot compete with it as a vocalist. . MIMUS POLYGLOTTUS (Boie.) Mocking-bird—It is now a permanent resident, being found all through the winter, which formerly I am told was not the case. Although it builds, and spends its life, generally in the close vicinity of the homestead, I have always found it very distrustful about its carefully con- cealed nest, and prone to desert it on slight provocation. It is generally believed among the negroes, that if young mocking birds be confined in a cage, although the parent birds will feed them at first, and exhibit the greatest anxiety to procure them their liberty, yet when they find that this is impossible, they invariably bring them something which poisons them. Unfor- tunately I have never been able to decide this by experiment. As an imitator of the notes of other birds, and sounds with which it is familiar, it is certainly unequalled by anything I have ever heard, although in this respect some individuals are much more proficient than others. In listening to an accomplished mocking bird one hears the most vivid impersonation of the songs of many birds, the chirping of young chickens, the cry of the little sparrow- hawk, the twittering of a fiock of partridges, followed by their frightened scream as a hawk dashes among them, this last performance is a great favourite with the mocking bird, who seems to enjoy dwelling upon a scene which he has probably often witnessed. Perhaps the nervous excitement, caused by the tragedy which he has beheld from the safe shelter of some thick On, Birds observed in Amelia County, Virginia. 67 bush, has impressed it upon hismind. They are most pugnacious birds themselves, attacking and vanquishing every bird which frequents the neighbourhood of the house near which they have established themselves. In the Purple Grackle, however, they find more than their match, and the contest between them always ends in the defeat of the mocking-birds, and their expulsion from the vicinity. Although it is such a perfect mimic, yet as a vocalist I do not think it approaches to our own song thrush. It some- times sings to itself at night, in a low, monotonous, dreamy sort of way, and several of them outside my window, have often thus kept me awake in the hot summer nights. Its life is protected by law, and its exportation from the State prohibited. GALEOSCOPTES CAROLINENSIS (Caban.) Cat-Bird—It arrives about the end of April. The earliest date I have seen it was on the 23rd, though I heard it squalling in the bushes late on the previous evening. They remain until autumn, and from every bunch of briars, and the bushes lining the streams, comes their absurdly kitten-like ery; and though they dive into the thickest part on the first alarm, they are not shy birds, but in half a minute or s9, will come out and mew at you a few yards further off They sing rather well, and are tolerably good imitators of the notes of other birds. They are protected by law. _ SIALIA SIALIS (Band.) Blwe-Bird—tThere is something about this little bird which, though it differs so much in colour yet, strikingly reminds us of the English Robin. It is I believe a partial migrant, appearing in flocks in the end of February, and again in October ; but they may be seen at any time of the year sitting on some post or twig, and flying to the ground now and then, to pounce on some grub or insect, and flitting down the fence from post to post in front, as one rides along the road. They breed early in spring, and generally lay their pale blue eggs in a hole in some decayed tree or post. They are protected by law. REGULUS SATRAPA (Licht.) Gold-Crest—This is a winter visitor. During some years I have found it not at all uncommon, and in others I have not seen a single specimen the whole winter. The earliest date I have observed its arrival has been the 2nd of December ; but it is more common in January. It is generally found in pairs, frequenting chiefly deciduous timber, often alone 68 Scientific Proceedings, Royal Dublin Society. though sometimes in company with other small insectivorous birds. POLIOPTILA CHRULEA (Sclat.) Blue-gray Gnat-catcher—The earliest note I have of its arrival is the Ist of April. I think the males come a little before the females. They remain until autumn, and build a beautiful, thick, felt-like nest, strikingly resembling that of the ruby-throated humming-bird, only of course larger ; the rim, however, is not turned in as in the humming-bird’s nest. I have sat, watch in hand, looking at it feeding its young, and found the same bird return about every two minutes; but insects were abundant, and it never had to go far—indeed, it was generally in sight all the time. LOPHOPHANES BICOLOR (Bonap.) Tufted Tit—This bird is very abundant, the most so I think of the Tit family, being found commonly all the year, but especially in spring and summer, arriving in numbers about the middle of February. In summer it is found chiefly among deciduous trees, in winter it seems to prefer the shelter of the pine woods. I have found it building in: holes in trees, at some height from the ground. Its call-note is a Clear whistle; its note of alarm resembles “is-is-ha is-ha- ah-ah.” PARUS CAROLINENSIS (Aud.) Carolina Tit—It is a permanent resident, and common throughout the year, but still I believe a partial migrant. It very much resembles the English cole tit, both in habit, and general effect. It is a busy, fussy little bird, scolding and chattering at an intruder in its haunts, and busily searching for insects all the time. It generally selects for its nest some old deserted hole of the downy woodpecker, so common in decayed timber by the river sides. SITTA CAROLINENSIS (Lath.) White-bellied Nuthatch—Com- mon throughout the whole year. In early spring their courtship is very amusing. J have seen as early as the 18th February, two or even more males, following one female, up and down the tree stems, and round and round, with their tails spread out to the utmost, and performing all sorts of strange antics; but I have never seen them fight for the possession of the fair one, as many birds do. Yet this nuthatch is by no means deficient in courage; for I have seen it attack a Blue-bird, who is generally well able to take care of himself, and snatch from it a large white grub On Birds observed in Amelia Cownty, Virginia. 69 which it had caught, and to eat which at its leisure, it had flown to a tree on which the nuthatch was searching for insects. SITTA CANADENSIS (Linn.) Red-bellied Nuthatch—On the 10th of January, during some ver~v cold weather, with snow on the ground and the thermometer below zero, I noticed a pair of small nuthatches, whose ery was not familiar to me, fly across the road and light on a tree behind me. I followed them, and easily approached within a few feet. They remained for some time running over the boughs close above my head, and almost within reach, and were easily identified as the present species ; but hav- ing no gun I was unable to secure one. This is the oe occasion on which I have met this bird in Virginia. CERTHIA FAMILIARIS (Linn.) Brown Creeper.—This is a winter visitor, and generally arrives rather late. I have never noticed it before the 22nd of December, nor have I seen it after the 5th of April. It is a solitary bird, being generally found singly, though sometimes in pairs. It is not very common, and seems to prefer large tracts of timber, to the trees round the homestead. TROGLODYTES LUDOVICIANUS (Bonap.) Carolina Wren.—lIt is very common all the year, and does not seem to migrate even locally. Its song of “ dear-wife, dear-wife,’ may be heard at almost any season of the year, on a fine day, from the uppertwigs of a heap of brushwood, into which it dives as soon as youappear. Itisa familiar, fussy little bird, in habits and manner very like our own wren. It generally hatches out its large family very early, and they are probably the first young birds one sees in the spring. : TROGLODYTES AEDON (Vieill.) House Wren.—In appearance it reminds me more of the European bird, than any other of the Virginia wrens do. I have only noticed it in summer, when breeding, during which time it always remains about the home- stead. Its song is good, and very sweet, and it is protected by law. TROGLODYTES PARVULUS VAR. HYEMALIS (Vielll.) WinterWren. —This little bird comes to Virginia for the cold months of the year, and I have not found it very common, and always singly Though not a shy bird, itis not as fond of human society as the two preceding species, and is seldom seen near the house, but prefers the wild forest, or the timber and brushwood growing by 70 Scientific Proceedings, Royal Dublin Society. some lonely river’s bank. It seems to me to be generally darker in colour than the European wren, and rather stronger on the wing. CISTOTHORUS STELLARIS (Caban.) Short-billed Marsh Wren.— I have occasionally met with this bird on the margins of swampy ponds, but have not found it common. ANTHUS LUDOVICIANUS (Licht.) Titlark.—It arrives in flocks early in March. The first I have noticed was on the 6th of that mouth. They make a stay of some weeks, longer or shorter according to the weather, and especially frequent newly ploughed lands. A few individuals remain long after the flocks have gone northward, but I doubt if any of them breed in the district, They appear again in autumn, in smaller flocks, but do not stay so long, though an occasional bird may be met with all through the winter. I have notes of having seen it on the Ist of Decem- ber, and on the 15th of January. MnrorittTa VARIA (Vieill.) Black-and-White Creepvng-Warb- ler.—Common. It arrives generally in the beginning of April. The earliest I have noticed was March the 30th. The males appear to arrive a considerable time before the females, and to be generally more numerous. In its way of running about the bark of trees, it much resembles the brown creeper, but it visits the smaller branches more than that bird does. Its song is a run of three notes, ascending by full tones, repeated four times, and ending with a single note one tone below the lowest of the ~ others; but it is so rapid that it is difficult to distinguish it with certainty. . PARULA AMERICANA (Bonap.) Blue Yellow-backed Warbler. —Not a common bird, and some years I have not seen it at all. I have only noticed it in spring and early summer. ‘The earliest I have taken was on the 13th of April. Itis generally found in pairs, among deciduous timber near some stream. Its song is a trill, ending with an abrupt jerk, like “ whee-t.” . DENDRECA CORONATA (Baird.) Yellow-rumped Warbler.— This is one of the commonest warblers in the district, and spends great part of the year there. They come about the end of April, or the beginning of May, and remain until very late in the autumn. On one cccasion I met a small flock on the 16th February during some very warm weather, ina sheltered valley ina On Birds observed in Anelia County, Virginia. 71 Y> 9 pine wood, and secured one; but with this exception I have never met with it after winter has thoroughly set in. DENDR@CA BLACKBURNIZ (Baird.) Blackburnian Warbler. —TI have never met this bird in the district but once. On Sep- tember the 4th I took a young male of the year among some tall forest trees near my house. DENDR@CA STRIATA (Baird.) Black-polled Warbler. Itis not a common bird, and during several years I have not seen it at all. I have only noticed it in spring, when I have found it among deciduous timber. ‘The earliest note I have of its arrival is the 13th of May. DENDRGCA CERULESCENS(Baird.) Black-throated Blue Warbler. —This handsome warbler is not very common, but may be obtained any day in the latter part of May at a place they have been observed to frequent, and every year one may be found now and then in the forest during spring and early summer; indeed I have never seen them except in deciduous timber. They are always in pairs, or a single male by himself. They arrive about the middle of May; the earliest I have noticed was on the 10th of that month. DENDRG@CA PINUS (Baird.) Pine Warbler.—This little bird out- numbers all the other Virginia warblers manyfold. The earliest date I have noted ofits arrival is the 2nd of March, and it generally appears before the middle of the month. In about a week after its first arrival it is quite numerous, keeping itself exclusively to the pine woods, and by the middle of May those who intend to go further north have left, though a large number remain during the summer and build in the pine woods; indeed during spring and summer I have never seen one away from the pines. Karly in October the return flight begins, and they come for some time in great numbers. Strange to say they then avoid the pine woods, and are found chiefly near the edges of the deciduous forests, and along the snake fences in the open land. One fence near my house has always been a favourite locality with the autumn flocks, which are composed largely of young birds, and every autumn I have seen them there in great numbers, though in spring I have never seen one on it. They are pugnacious little birds, and I have often seen them in autumn attack the tufted tits and chip- sparrows. ‘The former always fledignominiously, but the plucky 72 Scientific Proceedings, Royal Dublin Society. little sparrows like nothing better than a rough-and-tumble fight, yet, with their stout bills and their warlike dispositions, I could never see that they gained any advantage over the warblers, who in spite of their feeble appearance seemed quite their equals. Their song is rather sweet, but consists of only two notes very rapidly repeated. DENDR@CA DISCOLOR (Baird.) Prairie Warbler—A summer visitor, and not common. ‘The earliest note I have of its arrival is the 29th of May, but I have no doubt it comes much earlier, as I have found its eggs hard-set on the 1st of June. As its nesting has been but rarely observed I shall describe it. It had built in the fork of a dogwood bush about eight feet from the ground. The external diameter of the nest was 3:10 inches, in- ternal diameter 1-70; depth, external, 3 inches; internal, 1:60. It was composed of dry grass and fine grass stems, mixed with soft vegetable down, and long shining vegetable fibres like tow, and lined with the finest of these materials, chiefly very fine stems and cotton. It contained four eggs which were white, specked with dark and light shades of brown, the latter having a lilac tinge. These specks are massed together near the larger end, forming a very distinct ring round the egg. Although called the Prairie warbler it confines itself almost entirely to trees and brushwood. SEIURUS AURICAPILLUS (Swains.) Golden-crowned Thrush.— This little bird is not uncommon in spring and summer. I have taken it first on the 17th of May, and have found it in full song and apparently breeding on the 25th of that month. It sings with a monotonous, unmusical note. SEIURUS LUDOVICIANUS (Bonap.) Long-billed Water Thrush.— I have first observed its arrival from the south on the 16th of April, after which, in spring and summer, one may commonly hear in the woods its song, resembling “ tu-wee, tu-wee, tu-wee, te witte witte witte.” Itis fond of running over the mud by the river-side, catching insects, and jerking up its tail in a very wagtail-like way, but it is also commonly found in the woods far from water, generally, I think, in spring. GEOTHLYPIS TRICHAS (Caban.) Black-masked Ground-warbler. —This very handsome little bird, sometimes called the Maryland Yellow-throat, is common in spring and summer near swampy On Birds observed in Amelia County, Virginia. 73 ponds, some seasons much more so than others. The earliest I have taken was on the 10th of April. Its song is very peculiar, though not musical, resembling “ éete-wet-t,” generally three times repeated. It always remains near the ground, among the thick low bushes. Its note of alarm is “cher-r,” delivered in a very wren-like manner, as it peeps at the intruder from the thickest part of the cover. ICTERIA VIRENS (Baird.) Yellow-breasted Chat.—They come every spring, and remain during the summer. The earliest arrival I have noted was on the 30th of April, and sometimes | have not seen them until nearly the middle of May. It is a handsome bird, and its song, though rather metallic, is not bad. SETOPHAGA RUTICILLA (Swains.) American Redstart—This is another very handsome little bird. It prefers trees to low bushes, and is generally seen at some height fromthe ground. It arrives early in May, the first comers being single males. The earliest I have noticed was on the 23rd of April. They pass again in September in little families, but some remain throughout the summer. Their song is rather metallic, and resembles “ d'way-de-de-da-le,” repeated perhaps two or three times. PROGNE PURPUREA (Linn.) Purple Martin.—I1 have taken the first purple martin on the 2nd May. They remain all the summer,andare very common, especially frequenting the homestead, where a box, like a small pigeon cot, is often erected on a pole for them to nest in. They are encouraged to build near the farmyard, in order that they may protect the poultry, by mobbing any hawk which may come prowling about. PETROCHELIDON LUNIFRONS (Baird.) Cliff Swallow.—I have only seen this bird once in Virginia. On 18th May, 1878, I saw a single pair, hawking about for some time in company with other swallows, of which large numbers were present at the time. HIRUNDO HORREORUM (Barton.) American Barn-swallow.— This bird, which so forcibly reminds one of our own chimney swallow, arrives in the first part of May, the 2nd of that month being the earliest date on which I have noticed it. They remain but a short time and then go on to the north. A few may be seen returning in autumn, but they pass without stopping, and one does not see so much of them as in spring. 74 Scientific Proceedings, Royal Dublin Society. HiRUNDO BICOLOR (Vieill.) White-bellied Swallow.—lIt arrives in company with the last species, and their migrating movements seem very similar. They are about equally numerous, but H. bicolor seems perhaps to mix more freely with other species than does H. horreorum. STELGIDOPTERYX SERRIPENNIS (Baird.) Rough-vwinged Swallow. —This is the most numerously represented species among the swallows. It arrives at least a fortnight earlier than the two preceding species, and in considerable numbers. The earliest that I have taken was on the 17th April, and though most of them appear to leave by the beginning of June, yet a few may be seen now and then throughout the summer. CoTYLE RIPARIA (Boie.) Sand Martin—I have never taken this species, but I believe I have seen it not unfrequently, and once, 18th May, I have certainly done so. VIREOSYLVIA OLIVACEA (Bonap.) Red-eyed Vireo—In summer this is perhaps the commonest bird found in the woods. I have not noticed its arrival as soon as many of the other small spring migrants—not, indeed, until May is well advanced. They are indefatigable in hunting for larvee, on which I believe they chiefly subsist, but on one occasion I saw one eating a large brownish beetle or cockroach, holding it on the bough with its foot, picking off first the legs and wings, and shifting its foot now and then to get a better hold. During the blazing heat of the midday sun, when the leaves hang down from the trees, when all life is still, and the woods seem asleep, the little red-eyed vireo may yet be seen hopping quietly about among the branches, the only living thing that has energy to move. VIREO NOVEBORACENSIS (Borap.) White-eyed Vireo.—Not nearly so common as the last, and is found among the thick bushes which border the streams and rivers instead of in the woods. The earliest note I have of its arrival is 20th of April. Its song is very marked and peculiar, though not musical, and-resembles “ kit-a-witch-ha-wai-e-o.” . AMPELIS CEDRORUM (Sclat.) Cedar Bird.—This is a winter visitor, being most common in December. I aoubt if any of them nest in the district, though I have taken immature birds as early as August the 7th. I have seen it stated that they are perfectly mute, but although they are remarkably silent birds, On Birds observed vr Amelia County, Virginia. 15 they often utter a low call note resembling “isth,” like the noise made by drawing the breath between the teeth. COLLURIO LUDOVICIANUS (Baird.) Logger-head Shrike—This bird is by no means common. I tooka pair on March the 16th and 20th, and have occasionally seen a solitary individual in other years. The male of the pair I took contained a number of feathers of the song sparrow. PYRANGA RUBRA (Vieill.) Scarlet Tanager.—This is not a common bird, but a few may be seen every summer. The first I have noted was on the 29th of April. They remain through- out the summer, and in some years are more plentiful than in others. PYRANGA STIVA (Vieill) Summer Red-bird.—Common throughout spring, summer, and autumn, arriving in the end of April. For several years I have noticed it first on the 24th, and once on the 21st of that month. At onetime I thought the male arrived before the female, but later observations convinced me that this was not the case, but the bright scarlet plumage makes him a much more conspicuous object than his mate, whosedull dress often causes her to be overlooked. His song is rather good, and the bright colour of the male makes him a handsome object among the green leaves. They are always found in the woods. CARPODACUS PURPUREUS (Gray.) Purple Finch—Not com- mon. Some years I have not noticed it atall. I have generally found it in spring, or the end of winter, frequenting cither the edges of deciduous forests, or the thick pine woods. CHRYSOMITRIS TRISTIS (Bonap.) American Goldfinch—All through the year they are not uncommon, but they arrive in large flocksin April, and during that month are very plentiful. They are locally known as the “lettuce-bird,” on account of their partiality for the seeds of that plant; and a large flock, if per- mitted, will soon cause great havoc in a garden among the beds of lettuce seeds that have been lately sown. It is an extremely handsome little bird in spring and summer, and a flock of them dressed in full nuptial plumage is very striking. PASSERCULUS SAVANNA (Bonap.) Savanna Sparrow.—This is a winter visitor. ‘The earliest arrival I have observed was on the 24th of October. They remain until quite late in the spring, but I do “not think any of them stay through the hot season. They are com- 76 Scientific Proceedings, Royal Dublin Society. mon in open fields, and creep away quickly through the grass, or run along the path before one’s horse like a mouse, often tumbling over a stone or clod in their haste, but exhibiting the greatest reluctance to take wing; but if persistently followed up, they will rise and fly a few aapihed yards before alighting. COTURNICULUS HENSLOWI (Bonap.) Henslow’s Sparrow.— This rare, or perhaps I should say very local little bird, I have met but on one occasion. On the 8th of April, when collecting early in the morning, I saw a sparrow dive into some low scrub, uttering a note that was strange to me. On being approached he darted from bush to bush, just as the European wren does, and soon hid himself away securely. However I sat down, and waited patiently, and in about ten minutes he came out and commenced searching about through the grass at the roots of the bushes and was secured. CoTURNICULUS PASSERINUS (Bonap.) Yellow-winged Sparrow. This little bird is not uncommon in summer in open fields, where there is coarse grass or stubble. There it may often be found singing its remarkably feeble song, from the top of some low bush or pile of stones. The earliest note I have of its arrival is the 30th of April. ZONOTRICHIA ALBICOLLIS (Bonap.) White-throated Sparrow.— It arrives in October, the earliest I have noted being on the 12th of the month. It remains throughout the winter and leaves again in April. I do not think I have ever seen them in May, except once when I shot one on the 10th of that month. They are hardly ever seen in the fields, like the preceding species, but confine themselves chiefly to the vicinity of the homestead. There however they are in winter, one of the commonest of the small birds, frequenting bushes, or piles of logs and brushwood, into which they dive when alarmed. As spring approaches they sing generally on a wet morning or when rain is threatening, if it be not too cold. Often just at dawn before getting up if have known that it was a misty morning by hearing the song of this little bird; it is a very poor or rather doleful performance, con- sisting of but five notes—one a high one, then three tones below, another repeated slowly four times. JUNCO HYEMALIS (Sclat.) Snow Bird.—They spend the winter in Virginia, coming soon after the first sharp frosts. The earliest On Birds observed in Ainelia County, Virginia. 77 T have noted was the 23rd of October. They are by far the most numerous of the small birds in winter, hundreds of them being often seen together. They generally begin to leave again in March, but an occasional straggler will sometimes remain until late in April. Two or three cold nights will sometimes bring back a few, when none have been seen for a week or more. I once noticed three on the 20th of April, and in another year, a solitary individual on the 23rd of that month. They must not be confounded with the Snow-bunting, which is known in Canada as the Snow-bird. SPIZELLA MONTICOLA (Baird.) American Tree-Sparrow—A rather uncommon winter visitor. I have taken it first on the 7th of December. Like all the species of the genus Syizella it shows, when in the district, no partiality for the farm-yard, but prefers trees and bushes in the open fields, or along the margins of woods. SPIZELLA PUSILLA (Bonap.) Sield Sparrow—It remains all the year, but seems most numerous in winter, when it congregates in little flocks of from ten to twenty. After a few very cold days their numbers always seem to increase, as if they had _ been re- inforced ky a partial migration from further north. They are chiefly met with on the bushes in the open fields, or along the road side. SPIZELLA SOCIALIS (Bonap.) Chipping Sparrow.—This little sparrow arrives in flocks late in March, and in a few days after its first appearance it becomes very plentiful. The earliest note I have of its arrival is the 23rd of March. The males fioht incessantly in the most determined manner, screaming and twittering most viciously, three or four battles being often carried on together close to each other, and they are so engrossed in their occupation, that one might almost take them in one’s hand; they fly up and down, and tumble over each other, and I once found one so exhausted that he was unable to fly. On catching him, I saw that he had all the feathers pulled off his forehead, and all his remaining tail feathers broken. It is a great fly catcher, and I have seen it capture, and pick to pieces, even large beetles. Its song consists of only one tone the same note repeated slowly three times, followed by a long rapid trill. SciEN. Proc., R.D.S. Vou, w1., Pt. m1. H 78 Scientific Proceedings, Royal Dublin Society. They leave during November, and by the end of the month not one remains. MELOSPIZA MELODIA (Baird.) Song Sparrow—They arrive in December, the earliest I have noted is on the 7th, and remain during the winter, leaving in spring as soon as the weather beginsto getwarm. Early in spring they sing incessantly, and their song is very sweet and pleasing. During their stay they frequent the vicinity of the homestead, in company with the white- throated sparrows. PASSERELLA ILIACA (Swains.) Jox-colowred Sparrow.—tThis is not an uncommon bird during winter, being generally seen singly. It comes rather late, the earliest arrival I have noted being November the 10th; and it leaves early. JI have never seen one after the 15th of March. Early in that month they sometimes congregate in little parties of five or six, and then disappear; but most of them have left by the end of February. GUIRACA CHRULEA (Swains.) Blwe Grosheak.—Not uncommon in the end of April, and in May. The earliest I have taken was on the 26th of April. They are generally found singly, or in pairs. Whether a few remain throughout the summer or not, I am. not certain. CYANOSPIZA CYANEA (Baird.) Indigo Bird.—For several years I have first noticed its arrival on April the 30th ; and they seem to be among the first birds to leave, departing soon after the young are strong on the wing. They are very common, and in spring they sing incessantly. Their song resembles “ éet-et-te-é, déet-eet-te-€, wet-et-te-é, tue tue tue tue,’ with a loud scolding | alarm note. ‘They very often, however, sing only part of their song. I have frequently seen them singing vigorously on the wing, as they fluttered and floated from one tree to another, a distance of sometimes as much as two hundred yards. The female seems much shyer than her mate, and partly owing to this, and partly to her more sober dress, is comparatively seldom seen. . CARDINALIS VIRGINIANUS (Bonap.) Curdinal Grosbeak.—This bird, often known in England as the Virginia Nightingale, is very common all the year round, and I believe does not migrate, even in the most partial manner. They were especially numerous On Birds observed in Amelia County, Virginia. 79 round my house, where they were not molested, and though they never assemble in flocks, I have counted as many as thirteen on one small tree near my corn house, nine of which were males. They are very bright, handsome birds, and their song is sweet and powerful, but rather monotonous. I have seen the female in spring, singing in the woods just as well as the male. They build their nest in some bush or low tree, generally only a few feet from the ground. It is generally composed chiefly of the stalks of the Michaelmas-Daisy (Aster Americanus), and I do not think I have ever seen a nest that had not some of this material in it. It is locally known as the Red-bird, and is pro- tected by law.. PIPILO ERYTHROPHTHALMUS (Vieill.) Red-eyed Towhee—lIt is commonly known as the Ground-robin. In March they are often quite numerous; the earliest that I have taken was on the 22nd of February. Some remain all the summer, and assemble in flocks in the autumn, and these being augmented probably by those migrating from the north, it becomes a very common bird in the beginning of October, After the middle of that month most of them have left, and I doubt if any remain during the coldest part of the year. It frequents thick bushes and under- wood, and always keeps near the ground. EREMOPHILA ALPESTRIS (Boie.) Shore Lark.—lIt comes to this district in flocks during winter. Some years I have not seen one; in others I have noticed that they appeared whenever the weather was unusually severe, and then only, leaving whenever it became the least warmer. They prefer open pasture fields, or stubble that has been grazed bare, and seem during their stay to be much attached to a locality which they consider suits them. I have always found them rather wild and hard to approach within shot; and I have noticed a flock that I had disturbed, fly over another flock—who were feeding in a valley where they had not observed me—and swoop down at them several times, until they induced them to rise and join them, when they all flew off out of danger. DoLIcHONYX oRYZIVoRUS (Swains.) Bob-o-link or Rice-bird. —Ii arrives in flocks about the middle of May. I have not seen it before the 8th of that month. They stay but a very short H 2 ScIEN. Proc., R.D.S. Vou. 111, Pv. 111. 80 Scientific Proceedings, Royal Dublin Society. time—only a few days—and then are not seen until autumn, when they pass as before. MoLorHRuS PECORIS (Swains.) Cowbird—They arrive in large flocks in the latter part of February ; I have taken them first on the 25th of that month. They remain for some time, frequenting in great numbers ground that has been newly sown, or where the grass has been burnt off. Whenever there is a return of cold hard weather they disappear, but the first few fine days bring them back again. With them are mixed flocks of the red-winged blackbird, and smaller flocks of the purple-grackle, which act in the same manner. When the weather has settled down to be warm and fine, the cowbirds leave for the north. AGELAIUS PHENICEUS (Vieill.) Red-winged Blackbird.—These arrive in flocks about the same time as the last; the earliest I have seen was on the 21st of February. They however remain throughout the summer, and during the nesting season frequent swampy places near rivers or ponds. The female often suspends her nest from the reeds about a foot or two above the water, while the male spends the whole day among the willows close by, singing and chasing the female whenever she appears. He comes up to her with a flood of song, his tail spread to the utmost, his wings extended and fluttering, displaying to the greatest ad- vantage the bright patch of scarlet. As he sails slowly up, he looks twice his real size, and is quite a beautiful bird. Then when she bolts, as she generally does, he chases her rapidly round and round, with much singing and squalling. STURNELLA MAGNA (Swains.) Meadow Lark.—A permanent resident, and very common. It frequents pastures and open lands, and does not seem +o migrate in any way. In winter they assemble in flocks, somewhat as the European starline does, but more scattered and irregular, and not in such numbers. In changing their quarters from one field to another, a few will get up and fly perhaps a quarter of a mile, followed at a distance of a few hundred yards by one or two more, and so on until the whole of them have assembled again, but I have never seen them fly in a compact mass, as starlings do. They build their nest in some hollow in the ground, and it is roofed over with grass stems, like that of the ortyx, but flatter. On Birds observed in Amelia County, Virginia. 81 IcTERUS SPURIUS (Bonap.) Orchard Oriole.—It arrives in May, the 8th of that month being the earliest that I have taken it. It remains throughout the summer, but is not very common. SCOLECOPHAGUS FERRUGINEUS (Swains.) Rusty Grackle—They arrive in flocks about the same time as the cowbirds, and associate with them. I have never taken them before the 19th of March. They leave when the weather gets warm, and return in November in flocks, passing south. The earliest date at which I have found them returning was on the 9th of November. QUISCALUS PURPUREUS (Bartram.) Purple Grackle—Arrive at the same time as the cowbirds (end of February), but do not associate with them so much as the last species, and are in smaller flocks. They remain until autumn. Numbers of them nested in some ivy-covered trees, near a house of one of my friends, and being very pugnacious they would permit no other bird to remain in the compound, or yard, as it is there called. They were very noisy, and assembled every evening making the most horrible, metallic, discordant sounds, intended, I believe, for song. I have always found them thus assembled before sunset on some high treetop, from the time the flocks first arrive, and their chatter can be heard at a long distance. CoRVUS AMERICANUS (Aud.) Crow—A permanent resident, and in its habits much like the rook. The flocks, however, are but, from three or four to twenty in number, and in its nesting it is solitary like the carrion crow, which it closely resembles. It has not, however, the pointed feathers on the neck like that bird, nor the bare skin at the base of the bill like the rook. Its voice is a much shorter “caw” than that of the rook, and more jerky, and reminds a new comer of a dog barking, though the resem- blanee seems to wear off when one gets accustomed to it. CYANURA CRISTATA (Swains.) Blue Jay.—I have not found this bird very common, it is most numerous, I think, in winter and spring. It is a shy bird, and generally keeps to the woods, and as much out of sight as possible. TYRANNUS CAROLINENSIS (Baird.) King Bird—The Bee- martin, as this bird is called in Virginia, comes in the end of April. I have noticed its arrival in different years, from the 23rd to the 28th of that month. It appears to have paired before its arrival, as I have always noticed two of them together from the 82 - Scientific Proceedings, Royal Dublin Society. first. It is a common bird throughout the summer and early autumn, and then leaves for winter quarters. Myrarcuus crinirus (Caban.) Great Crested Flycatcher— Not uncommon in the woods in summer. It arrives, I think, about the beginning of May, but the earliest that I have taken was on the 23rd. I have found it most common in warm summers. SAYORNIS FUSCUS (Baird.) Pewee Flycatcher.—lt arrives in ‘March, and leaves after the first frosts. But I have several times, to my no small surprise, seen it in the middle of winter, on the 3rd and 4th of January. It is a common bird in summer, and may often be seen perched on a post, or the top of a tobacco- barn. CONTOPUS VIRENS (Caban.) Wood Pewee.—It arrives in the middle of March. The earliest note I have of it is on the 10th. I have never seen it in winter though it will stay for some time after frost commences, and remains longer than the last species. It is common in the woods all through the warm weather. CERYLE ALCYON (Boie.) Belted Kingfisher—I have never seen this bird in winter. They appear in spring, and disappear when it gets cold, but I have unfortunately no notes of their arrival or departure. I have found it nesting in a hole ina steep bank, the side of a cutting through which the public road passed. Yet so cautious was the bird in approaching its nest, that I had great difficulty in finding it, and it eventually brought away its young brood in safety to the river, which was about a hundred yards off. CHORDEILES POPETUE (Baird.) Virginia Goatsucker.—This bird is locally known as the “bull-bat.” The earliest date at which I have noted its arrival was the 23rd of April. They soon become common, and remain until the middle of September. At that time I have seen focks of them sailing round high up in the air, after which they disappear entirely. They fly a good deal by day, but are then high up, only coming down and skimming near the ground in the early dawn or late in the evening. ANTROSTOMUS VOCIFERUS (Bonap.) Whip-poor-Will—I have noted first arrivals of this bird in different years from the 7th to the 17th of April. During May their cry is incessantly ringing through the woods in the morning and evening, especially if it happen to be a little cooler than usual. They are very tame, On Birds observed in. Amelia County, Virginia. 83 and if one remains quiet they will often come and cry within a few feet of one, generally selecting a log or rail, or some bare spot of ground. I have noticed that a white patch, where some mortac had formerly been made up, was always especially attrac- tive to them, and two or three of these patches were always fre- quented nightly by the males calling to their mates. On these white patches they were most conspicuous in their dark dress, and I believe that was their reason for frequenting them. ‘hey remain all the summer, and leave about the middle of September. Some years they are much more abundant than others. CHETURA PELAGICA (Baird.) Chimney Swift—My earliest note of its arrival is the 19th of April. It is common throughout summer and remains until autumn. TROCHILUS COLUBRIS (Linn.) Ruby-throated Humming-Bird. —lIt arrives in the beginning of May. I have taken it as soon as the 18th of April, but that is earlier than usual. For the first two weeks in May they are quite abundant; afterwards when many have passed north, they are not so numerous, though com- mon until autumn. After the 25th of August they are very numerous for a little time ; the young broods, I suppose, perhaps augmented by arrivals from the north. I have never noticed one after the Gth September, although in Lower Canada I have seen them up to the 7th. I have taken their nests, with the eggs hard set, on the 27th May and Ist of July. I have never seen the female act as Mr. Webber describes ;* mine when returning to their nests always flew up boldly, and settled on or near it, just as any other bird might do. T find that on account of the turned-in lp, with which these beautiful little nests are furnished, they will bear. being inclined at an angle of 135° from the perpendicular, or nearly upside down, before they wili allow the eggs to fall out. They are hot-tempered little birds, and I have often seen the males quarrelling with each other, darting up and down perpen- dicularly, to a height of twenty or thirty feet so rapidly that the eye can hardly follow them, uttering all the time a sharp, squeaky note of anger. I have sometimes myself been attacked in the same way by one of these little birds whose indignation I had in *‘¢ Wild Scenes and Song Birds.” 84 Scientific Proceedings, Royal Dublin Society. some manner aroused, and they dart up and down within three or four feet of one’s face squeaking most viciously, though there was no nest in the immediate vicinity that I could find, and I have never seen any such display when their nest has been approached. CoccyzUS AMERICANUS (Bonap.) Yellow-billed Cuccoo.—This bird is locally known as the “rain-crow,” from its being supposed to call before rain, or when rain is much wanted. I have generally noticed it most noisy in very sultry weather, and it will call persistently in the middle of the hottest summer’s day, when all other birds are silent. I once (June 30th) heard it calling at 10.30 P.M., no moon, after heavy rain. It comes early in May, and remains throughout the summer. The earliest arrival I have noted is the Ist of May. Picus vinLosus (Linn.) Hairy Woodpecker.—Not very com- mon. I think it is a resident all the year, but it is most usually seen in winter, spring, and early summer. PICUS PUBESCENS (Linn.) Downy Woodpecker—This is the commonest of the woodpeckers in the district, and the smallest. It remains throughout the year, but migrates partially I believe. SPHYRAPICUS VARIUS (Baird.) Yellow-bellied Woodpecker.— This is a common bird in the woods in winter, but leaves gene- rally before the end of March. The earliest note I have of its return is the 15th of October. I have noticed this woodpecker sitting on a tree soon after its arrival, constantly launching itself into the air, and catching insects on the wing like a flycatcher. I have also repeatedly found the crops of those I have shot con- taining numerous cedar berries. All woodpeckers seem to prefer deciduous timber, but this one may be found on the pine trees more frequently than the others. I think the females remain a little longer in the spring, and return a little earlier in the autumn than the males. This and the last are locally known as “sap-suckers.” HYLOTOMUS PILEATUS (Baird.) Pileated Woodpecker.—This large woodpecker, locally known as the “log cock,” is a per- manent resident. Its size, and its brilliant crest, make it a very striking object in the woods; and the beautiful pale primrose of the underside of the wing is very conspicuous when it is flying. On Birds observed in Amelia County, Virginia. 85 I have noticed, that in all the specimens I have taken, the iris of the male was fawn colour, and that of the female the colour of the inside of a pomegranate. CENTURUS CAROLINUS (Bonap.) Red-bellied Woodpecker— This bird remains all the year, and is not uncommon at any time. It is found chiefly in the deciduous forests, where there are large trees, and is seldom met with among the large bushes or smaller trees by the road-side, as P. villosus, and P. pubescens often are. MELANERPES ERYTHROCEPHALUS (Swains.) Red-headed Wood- pecker—This is the handsomest of the Virginia woodpeckers, and not very common. It is a summer bird, the earliest arrival I have noted is the 10th of May. On the 19th of September, 1877, my house was visited by quite an incursion of them; they were principally young birds, and remained for two or three days; and were, during that time, more numerous than all the other birds put together. I suppose they were the northern con- tingent going south. This woodpecker may often be found on single trees, away from the forest, or any other timber; indeed, it almost seems to prefer trees that are thus dotted about the open country, to masses of woods. COLAPTES AURATUS (Swains.) Golden-winged Woodpecker— Tt is locally known as the “yucka.” It is found all through the year, but I believe migrates partially. Their courtship in spring is very amusing. They may be seen,I think, more frequently on the ground than other woodpeckers, and I have often seen them perched crosswise on a bough, as birds generally do, instead of lengthwise, or on the stem in the more approved woodpecker fashion. SYRNIUM NEBULOSUM (Aud.) Barred Owl.—This is a rather common. species, about equally so with B. virginianus. They much frequent the woods round my house, and in spring make the most unearthly noises at night, laughing, screaming, and caterwauling at each other, like demons or madmen. Their usual note is in a higher tone than that of the great owl, and resembles “huh, huh, hoo, hooo, hooo.” They often hoot in the day-time, and even come out about 4p.m.,if rain is threatening. I have often sat near a tree on which the young were perched, and watched the proceedings of the parents. The male always seemed more anxious and bolder than the female. I have never found 86 ‘Scientific Proceedings, Royal Dublin Society. their stomachs to contain anything, except crayfish, and a sala- mander that lives under old logs. Scops Asio (Bonap.) Mottled Owl.—This little owl is very common, especially in July, when the young begin to fly. In the summer evenings may be constantly heard their long, plain- tive, tremulous cry: “, t, 01, U, u,” except before rain, when they are generally silent. The red and gray form seem to occur indis- criminately in any age or sex. The grays are not bad eating, tasting something like woodcock; but the red ones that I have tried, were not nice. Buzo VIRGINIANUS (Bonap.) Great Horned Owl—Not an uncommon bird, and its deep “hoooo-hoo-hoo,” may often be heard in the moonlight, or early dawn, especially in spring. In the distance their voice seems to have a tremulous tone, and the first note is the longest. A friend of mine shot one in the act of carrying off a ae and the bird smelt so dreadfully of its ee odoured captive, that he could not preserve the skin. FALCO SPARVERIUS (Linn.)