PENYWERN HOUSE MILITARY AND ENGINEERING COLLEGE, 2 PENYWERN ROAD, EARL'S COURT, S.W. PRINCIPAL-G. W. DE TUNZELMANN, B.Sc., M.I.E.E, Telegrams-" Tunzelmann, London." PUBLIC SERVICE AND UNIVERSITY DEPARTMENT.-For students preparing for the various branches of the Public Service or for Scholarships at, or entrance into, the Universities and Hospitals. ENGINEERING DEPARTMENT -The Complete Courses qualify_Students for entry into Cooper's Hill, the Central Institution, the Royal College of Science, and into Engineering Works. Special Courses in Electrical Engineering. The extensive Physical and Chemical Laboratories are fitted up in the most complete manner for both Elementary and Advanced Work. The College is supplied with very complete Geological Collections for practical instruction. Students are regularly sent to the College by Leading Engineers and Scientific Authorities, whose Names are given in the Prospectus. ST. THOMAS'S HOSPITAL MEDICAL SCHOOL, ALBERT EMBANKMENT, LONDON, S.E. TWO NATURAL SCIENCE SCHOLARSHIPS of £150 and £60 respectively. pen to First-year Students on entrance in OCTOBER. Special Classes in CHEMISTRY and PHYSICS, BOTANY and ZOOLOGY, are held throughout the Year, and may be joined at any time. Free Scholarships are given to distinguished Pupils of MERCHANT TAYLORS SCHOOL, the CITY OF LONDON SCHOOL, and EPSOM COLLEGE. Other Scholarships and Prizes of the Value of upwards of £300, the Mead Medal for Medicine, and the Ches Iden Medal for Surgery are awarded annually. The olly Medal and Prize. biennially, for Surgical Reports. ST. BARTHOLOMEW'S HOSPITA AND COLLEGE. INSTRUCTION IN PRELIMINARY SCIENCE Courses of Lectures and Practical Laboratory Instruction in BOL CHEMISTRY, and PHYSICS, adapted to the requirements of studying for the PRELIMINARY SCIENTIFIC (M.B.) EXA TION of the University of London are given by the Lecturers th the year. Special arrangements are made for Students wishing 1. for Examination in January and for those who have recently marit. Fee for the whole Course of Instruction, £18 185. For Particulars apply Personally or by Letter, Dr. T. WE Warden of the College, St. Bartholomew's Hospital, E.C. GEOLOGICAL SOCIETY OF LONDO The ANNIVERSARY MEETING of this Society will be e Society's Apartments, Burlington House, on FRIDAY, FEBRUA at 3 o'Clock p.m. WANTED.-A Resident Curator, Meter LOGICAL OBSERVER, and CARETAKER for the Ma Library Buildings of the Royal Institution of Cornwall, Tr £50 per Annum, with Rooms, Coal, and Gas-Applicat cates' own handwriti g, stating Age and Scientific qualifian Testimonials and References, to be forwarded, not later that RUARY 14, to MAJOR PARKYN, Truro. WANTED—“ Nature.” Nos. 427, 428, 472, and November 14, 1878. Nos. 618 and No. 651; 1882. No. 705: 1883. Price offered by F. ACM. Elmfield, Stoneygate, Leicester. TELESCOPES FOR SALE. Two very fine reflectors by Cook, diameter of mirror, st by na tively, perfect condition. Apply by letter-Mr. H., 30 Mar Cadogan Square. FOR SALE. A Collection of Minerals Rocks.-Particulars on application to "No. 1," NATS 29 Bedford Street, Strand. ALBERT EDWARD JAMRAC (Late CHARLES JAMRACH), 180 ST. GEORGE STREET EAST. Implements of Savage Warfare, Idols, Sacred Masks, Pervi Netsukis, China, Lacquer, Gongs, Shells, and other Curios. Prospectuses and all Particulars may be obtained from the Medical F. H. BUTLER, M.A. Oxon., Assoc.R.S Secretary, Mr. GEORGE RANDLE. G. H. MAKINS, Dean. EVENING LECTURES TO WORKING MEN. ROYAL COLLEGE OF SCIENCE, LONDON. "Some Recent The Third Co irse, consisting of Six Lectures on Advances in Metal urgy," by Prof. KOBERTS AUSIEN, C.B., FR.S., will be delivered at th: Museu n of Practical Geology, in Jer nyn Street. S. W., com nencing at 8 o'clock on MONDAY EVENING, FEBRUARY 20, 1893. Tickets may be ob ained by Working Men only on application at the Museum on Monda Evening, February 13, from 6 to 10 o'clock. Fee for he Curse 6d. Each applicant is requested to bring his name, address, and o upation written on a slip of paper, for which the Ticket will be exchanged throughth Y-ar. Special Instruction is given for the July Examina NATURAL HISTORY AGENCY, 158 BROMPTON ROAD, LONDON Dealer in Rocks, Minerals, Fossils, and other of Scientific Interest. NOW ON VIEW:-A large and varied assortment of Rocke cently obtained from West Shropshire and North Wales, indistrai Diabases, variegated Volcanic Ash, Agglomerate, and Bree from the Stiper Stones, Spotted Schists, and Granitite; also a exceptionally fine polished examples of Labradorite, Green Quartz, Agate, Jasper, and other Ornamental Stones, Pyrite tite from Cornwall: Chalk Polyzoa from Kent; and a Cou Ostrich Eggs. Sales by Auction. MONDAY, FEBRUARY 13. JABLE MICROSCOPICAL, BOTANICAL, AND NATURAL HISTORY LIBRARIES, SCIENTIFIC WORKS, &c. J. C. STEVENS will Sell by Auction, his Great Rooms, 38 King Street, Covent Garden, on MONDAY. BRUARY 13, at half-past 12 precisely, the Library of Microscopical other Scientific Works formed by the late H. F. Hailes, Esq., a cretary of the Quckett Microscopic Club, a small Library of Botanical orks formed by the late W. W Reeves. Esq., of Pickering, formerly sistant Secretary to the Royal Microscopical Society, also several other all Libraries on Natural History and Scientific Subjects, &c. jew Saturday prior, 10 till 4, and Morning of Sale, and Catalogues TUESDAY, FEBRUARY 14. LECTION OF COLEOPTERA AND LEPIDOPTERA, AND OTHER NATURAL HISTORY SPECIMENS. J. C. STEVENS will Sell by Auction, bis Great Rooms, 38 King Street, Covent Garden, W.C., on ESDAY, FEBRUARY 14, at half-past 12 precisely, a Collection European and Exotic Coleoptera, Heterocera from New Zealand, tish and Exotic Lepidoptera; also, Collection of Shells, Minerals, ads and Horns of Animals. Cabinets, Birds' Eggs, &c., &c. Day prior from 10 till 4 and Morning of Sale, and Catalogues had. SS-TOPPED BOXES, CARD TRAYS, &c. HUGH FULTON (Conchologist), 216 KING'S ROAD, LONDON, S.W. V LIST OF MICROSCOPIC SECTIONS OF INING MANY NEW AND Interesting SPECIMENS es of Collections of Minerals, Rocks, and Fossils, Apparatus and nces, Single Minerals, Chemical Minerals, Empty Cabinets, &c. NOVELTIES IN PRECIOUS STONES. ALL LISTS FREE OF JAMES R. GREGORY, HARLOTTE ST., FITZROY SQUARE, W. HROAT AND COUGH COMPTES RENDUS HEBDOMADAIRES DES SÉANCES DE L'ACADÉMIE DES SCIENCES. Vols. 4 to 23 26 to 33, 42, 43, 45 to 87, 90, 91. 28 Vols. Half Calf, the rest in Numbers (4 Tables, 2 Titles, and 7 Numbers wanting.) In all 75 Vols. 1837 to 1880. 10 10S. A long Series of this important Work, containing Articles by Aoust, Arago, Bailly, Berthelot, Bertrand, Biot, Cauchy, Chasles, Dupin, Encke, Faye, Gauss, Hermite, Jacobi, Jamin, Jordan, Lacroix, Leverrier, Libri, Moigno, Monge, Poinsot, Poisson, Poncelet, Saint Venant, Secchi, Serret, Sylvester, Verdet, and many others. COSMOS. Revue encyclopédique hebdomadaire des progrès des Sciences et de leurs applications aux Arts et l'Industrie. Fondée par B. R. de Monfort, redigée par l'Abbé Moigno. (First Series), 1859 to 1863, 10 Vols (S-cond Series), Les Mondes. 1863 to 1881, 56 Vols. Third Series. Vols. 1 to 3. In all 69 Vols. 8vo, Half Calf. 1859 to 1882. 10 10S. EDUCATIONAL TIMES. 1850 to December A Monthly Journal of Education, Science, and Literature. Vols. 4 to 43. 1890. 41 Vols. in 20, Cloth, and 2 in Numbers. £4 10s. Sets of this important Journal are very scarce. It contains valuable mathematical questions and solutions, the republication of which, in book form, did not commence until 1864. Pages 25 to 48 of Vol. 4, and the Title and Contents of Vol. 40 are want ng; otherwise it is perfect. COLLECTIONS OF MINERALS, ROCKS, OR FOSSILS, For the Use of Scudents, Science Teachers, Prospectors, &c., and to illustrate the leading Text-books, in Boxes, with Trays. 50 Specimens, 10s. 6d.; 100 do., 21s.; 200 do., 42s New Price List of Minerals, Rocks, and Stratigraphical Seriesof Foss Post Free. ROCK SECTIONS for the MICROSCOPE from 1s. 6d. each, Pos Free. CATALOGUES GRATIS. CABINETS, GLASS-CAPPED BOXES, TRAYS, HAMMERS, &c., always in Stock. and Dryness, Tickling and Irritation, inducing Cough, and affect- LIVING SPECIMENS FOR THE ing the Voice. For these symptoms use EPPS'S GLYCERINE JUJUBES. act with the glands at the moment they are excited by the act of he Glycerine in these agreeable Confections becomes actively ld only in Boxes, 74d., and Tins, 15. 1fd., Labelled. S EPPS & CO., Homoeopathic Chemists, LONDON. MICROSCOPE. Volvox globator, Epistylis flavicans, Stentor cœruleus, Spongilla fluviatilis, Rhinops vitrea, Lophopus crystallinus, and other objects Amoeba, Hydra, Spirogyra, and other types (Animal and Vegetable) for Students. Specimen Tube, with Drawing and Description. One Shilling, Post Free. T. E. BOLTON, FARLEY ROAD, MALVERN LINK. CASSELL & COMPANY, Limited, Ludgate Hill, London; and all Bookser By J. F. BLAKE. Now Ready. Pp. 404, Pl. 6, Price 9s. Net. DULAU & CO. ANNALS OF BRITISH GEOLOGY THURSDAY, FEBRUARY 9, 1893. THE MILKY WAY. → Milky Way from the North Pole to 10° of South Declination, drawn at the Earl of Rosse's Observaory at Birr Castle. By Otto Boeddicker. (London: Longmans, Green, and Co., 1892.) R. OTTO BOEDDICKER devoted the clear moonless nights for five years, from October 1884 to tober 1889, to delineating the Milky Way as it apared to his unaided eyes at Parsonstown, Ireland. His awings were deposited in the library of the Royal stronomical Society, and a note accompanying them as read at the meeting of the Society in November 889. The work now before us consists of four excellent thographic reproductions of these drawings, a brief ntroductory preface being added by Dr. Boeddicker. The working maps for the drawings were taken from Argelander's "Uranometria Nova," the Milky Way being nserted by means of stump and lead pencil. This medium was found very unsuitable for photographic reproduction, and in preparing the lithographic stones for these charts photography was used for the stars, and the Milky Way was introduced by hand work. Mr. W. H. Wesley, the Assistant Secretary of the Royal Astronomical Society, is responsible for this latter portion of the work, and the results are a splendid testimony to his care and skill. Dr. Boeddicker is to be congratulated upon having secured the services of so excellent an artist. Plate I. is a detailed drawing of the Section CygnusScutum, Plate II. of the Section Cassiopeia, and Plate III. of the Section Aurigæ-Gemini-Monocerotis. In these plates an attempt has been made to represent accurately the appearance of the galaxy, all the differences of luminosity being represented as they actually appeared to Dr. Boeddicker. In Plate IV. a general view on a smaller scale of the whole Milky Way from the North Pole to 10° south declination is given, the contrast being deliberately exaggerated in order to bring out clearly all the details. The area of the Milky Way indicated on these drawings is very much greater than that on any previously published representations, while for delicate details and faithful reproduction of contrast the plates are unapproached. In many respects Dr. Boeddicker's drawings are a new revelation, branches, wisps, and feelers being shown extending from the main body so as to include stars, clusters and nebula, and even whole constellations not previously recognized as connected with or forming part of the Milky Way. Polaris, y Arietis, Præsepe, the Pleiades, the Hyades, the great nebula in Andromeda, and nearly the whole of the constellation Orion, are thus joined to the galactic circle. Numerous bright patches, channels, rifts, and interlacing lines of luminous matter hitherto unsuspected are revealed by Dr. Boeddicker's long and patient work, and exponents of disc, spiral, and other theories as to the construction of the Milky Way will find considerable difficulty in accounting for the details shown. It is very difficult to compare drawings of the Milky Way made by different observers without optical aid. 337 There are such wide variations in unaided vision, so many peculiarities introduced by long and short sight, by astigmatism, by irradiation in the retina, and by other physical and physiological imperfections, that it may safely be asserted that no two persons get exactly the same naked eye impression of such a vague object as the Milky Way. As no details are given about Dr. Boeddicker's eyes we are probably justified in inferring that they are practically normal, but we doubt whether any other observer, even with special training, could check or correct these charts with reasonable prospect of convincing the original artist of error in the representation of the Milky Way as it appeared to him. Individual peculiarities of sight are minimized by the use of slight optical aid, and two equally experienced observers would be more likely to agree in their delineations of the Milky Way if they used similar telescopes, of say 1-inch aperture, or even ordinary opera glasses. Dr. Boeddicker's appeal to other observers to verify and correct work will probably bring him plenty of correspondence, but can scarcely lead to any important correction in his magnificent drawings. 66 " his Dr. Boeddicker considers that "the first step necessary towards the knowledge of the sidereal universe is a thorough acquaintance with the Milky Way as it appears to the naked eye,” and hopes that by comparison and the superposition of naked-eye drawings on photographs some knowledge of the structure of the Milky Way in the line of sight may be obtained." This idea is founded on the theory that there is a direct connection between the magnitudes of stars and their distances. Littrow's analysis of Argelander's catalogue of stars certainly seemed to justify belief in this connection, but recent work has entirely disproved the hypothesis. Measurements of the parallax of stars indubitably prove that some faint stars are near, while some of the brightest are at such distances as to have no appreciable parallax. Thus a Orionis, a Virginis, a Leonis, and a Cygni have no parallax, while the 5th magnitude star 61 Cygni has a parallax of between o"4 and o′′5. Photographs of the Pleiades show that we have in that cluster stars differing by as much as 13 magnitudes at approximately the same distance from us. Russell's photograph of a Crucis plainly indicates a direct physical connection between that star and many stars of the 14th and 15th magnitudes which should, according to the theory, be nearly 1000 times more distant. Streaks of nebulæ connect a Cygni and y Cygni with long lines and stars of about the 16th magnitude in Dr. Max Wolf's photographs of the Milky Way. From considerations of parallax observations of stars and from examination of photographs we are forced to conclude that there is no real connection between magnitude and distance, and that the differences of magnitude of stars are due to differences of size and physical condition. Stars differ enormously in lightgiving power, and the actual light emitted by a Cygni must be nearly a million times greater than that from the faint stars directly connected with it and at practically the same distance from us. There is therefore very little chance of adding to our knowledge of the Milky Way "in the line of sight" by superposition of naked-eye drawings on photographs. In his preface Dr. Boeddicker frequently speaks of |
