December 5, 1895] 



NATURE 



109 



Mr. W. H. Pennington. The volume represents a large 

 amount of industry and research on the part of associates of 

 the Society, and it will give a stimulus to the study of science 

 in Lancashire. Another volume just published by a provincial 

 Society is the Annual Report and Transactions {\o\. xxix.) of the 

 Naturalists' Field Club and Archaeological Society of North 

 Staffordshire. This volume is, as a whole, more scientific in 

 character than that of the Rochdale Society. Reports are given 

 i)f the work of the various sections of the Society concerned 

 \\ ith observations in different branches of science, and we notice, 

 among the other contents, an address by Dr. W. Hind ; a paper 

 nn glacial theories, past and present, and their application to 

 Staffordshire, by Mr. C. E. De Ranee, and one on the occur- 

 rence of marine fossils in the coal-measures of North Stafford- 

 shire, by Mr. John Ward. Both volumes are very creditable 

 records of the work of provincial scientific Societies. 



We have on our table several new editions of books pre- 

 viously reviewed in Nature. Among these volumes is a 

 second edition of " Modern Microscopy " (Bailliere, Tindall, 

 ind Cox), a handbook for beginners, comprising a section on 



I- microscope, and instructions for its use, by Mr. M. I. 

 ' I OSS ; and on the preparation and mounting of microscopic 

 objects, by Mr. Martin J. Cole. We welcome a second 

 edition of "A Manual of Physics" by Dr. W. Peddie, 

 bearing the same publishers' names. The work is an 

 admirable text-book, which students of physics would do 

 well to obtain. Messrs. Longmans, Green, and Co. have 

 jHiblished an eighth edition of Mr. John Thornton's "Ele- 

 mentary Physiography"; and Messrs. Blackie and Son, the 

 ninth edition of " Earth- Knowledge," by Mr. W. Jerome 

 Harrison and H. Rowland Wakefield ; both these books being 

 intended for students in the physiography classes of the De- 

 partment of Science and Art. Messrs. Blackie have issued 

 also a fourth revised and enlarged edition of " Elementary 

 Inorganic Chemistry," by Prof. A. Humboldt Sexton. 



The additions to the Zoological Society's Gardens during 

 the past week include a White-backed Piping Crow {Gymno- 

 rhina leiuonota) from Australia, presented by Mr. Percy A. 

 (iore ; a White-headed Sea-Eagle {Holuettis leiuocephaltis) from 

 Newfoundland, presented by Mr. Leicester Curzon Howe ; a 

 Chough {Pyrhocorax gractilus), British, presented by Mr. 

 Gerald Strickland : two Blood-breasted Pigeons {Phlogcenas 

 cruentata) from the Philippine Islands, presented by Captain 

 Harvey; two Greater Sulphur-crested Cockatoos [Cacatua 

 galerita), a Crimson-winged Parrakeet (Aprostnictiis erythrop- 

 terus) from Australia, presented by Mrs. Morgan ; two Barbary 

 Wild Sheep (Ovis tragelapkus, 6 $) from North Africa, 

 deposited ; a Great Northern Diver {Colyiiibtis glacialis), twelve 

 Snow Buntings {Plectrophanes nivalis), four Dunlins ( Tringa 

 alpina), a Golden Plover Charadrius plnvialis), a Grey 

 Plover {Squatareola helvetica), British, a Bahama Duck 

 (Dafila bahantensis) from South America, four Green-winged 

 Doves {Chalcophaps indica) from India, two Bearded Vultures 

 (Gypatus barbatus), European, purchased. 



OUR ASTRONOMICAL COLUMN. 



Positions of the New Comets.— As we go to press, the 

 following calculated positions for the two new comets have been 

 received from Kiel. The places are for Berlin midnight. 

 Perrine's Coviet. 

 Date. R.A. Decl. 



h. m. s. o / 



Dec. 7 ... 14 52 37 ... -13 37-2 



Brooks's Comet. 

 Date. R.A. Dect. 



h. m. s. o / 



Dec 8 ... 8 II 2 ... -f-44 28*2 



10 ... 7 45 57 ••■ +51^ 367 



12 ... 7 16 42 ... -t-57 23-5 



NO. 1362, VOL. 53] 



Swift's Comet, 1895 H-— Another comet has put in a claim 

 to be considered the long-lost comet of Lexell ; and the claim is 

 perhaps based on a better foundation than any of the other 

 competitors can show. Le Verrier has supi^rted the comets of 

 Faye and De Vico ; more recently Brooks' comet of 1889 found 

 a supporter in Dr. Chandler, but the claim was routed by the 

 calculations of Mr. Lane Poor. M. Schulhof looked favourably 

 for a while on the merits of Finlay, but finally inclined to the 

 belief that the two comets had a common origin rather than 

 absolute identity. The new comet Swift has much to recom- 

 mend it to the consideration of a.stronomers {Astr. Nach., 

 No. 3318). In the first place, Tisserand's criterion is fairly well 

 satisfied ; next, the closest approach to the orbit of Jupiter, in 

 the case of both comets, falls very nearly in the same longitude ; 

 further, of the various orbits along which Le Verrier showed 

 Lexell might move, after the heavy perturbations of 1779, one 

 can be selected which agrees very closely with the orbit of 

 Swift. Moreover, this particular selection of the various orbits 

 suggested by Le Verrier is supported by Clausens's work on the 

 same comet. Here is the comparison : — 



Long, of perihelion 



Long, of node 



Inclination 



Excentricity 



Semi-axis major ... 



" Tisserand's criterion " 



Long, of approach to 7i 



It is a question if the agreement is not too good, for the 

 comet of Swift made a close approach to Jupiter in 1886, and 

 underwent heavy perturbations. M. Schulhof is at present 

 considering these ; but till their character and amount is known, 

 it is premature to decide this vexed question of identity. It is 

 possible the question will not be set at rest till 1931, for the 

 returns previous to that date are not very favourable for 

 observation, and the comet may pass unnoticed. But in any 

 case observations in large telescopes should be prosecuted as 

 long as possible, in order to determine the mean motion with 

 accuracy, with the view of assisting the re-discovery. 



A Peculiar Variable Star.— A variable star recently dis- 

 covered by Mr. Chandler presents some very remarkable 

 features (^Astronomical Journal, No. 358). In the singularly 

 short period of 5h. 3i-i5m., the magnitude of the star varies 

 between 8*9 and 97, so that three or four of the principal 

 phases may be observed in a single night. The variations are 

 distinctly not of the Algol type, but maxima and minima are 

 equally and sharply marked. The light-curve is also unlike 

 those of the other class of short-period variables, such as 

 5 Cephei and i\ Aquilse, inasmuch as the rise to maximum and 

 fall to minimum take place in equal periods. 



The newly-discovered variable is designated U Pegasi, and its 

 position for 1900 is R.A. 23h. 52m. 53s., Decl. IS°23''9; the 

 elements of the variability are as follows : — 



";^nhs''-3--9-os.E. 



The probable error of the period is believed to be only a 

 moderate fraction of a second. 



It appears that Dr. Chandler discovered the variability of the 

 star more than a year ago, but erroneously inferred that it was 

 of the Algol type with a period of 2*06 days. Mr. Yendell con- 

 firmed the variability, and concluded that the period was o-69d., 

 or one-third of that assigned by Dr. Chandler ; but it was still 

 supposed to be of the Algol type. A more recent discussion of 

 the observations, however, has established that this period must 

 again be divided by three, and that the light-curve has the 

 character to which reference is made above. 



Saturn's Rings. — Some remarkable observations of the rings 

 of Saturn are reported by A. Mascari, of the Catania Observa- 

 tory {Ast. Nach., 3318). Observing from July 25 to August 6 

 of the present year, he noticed certain dark spots on the crape 

 ring, as well as bright ones on the brighter rings. Perhaps the 

 most curious feature of these spots is their apparent permanence 

 of form ; for this is not easy to explain if the idea that the rings 

 are composed of separate particles be accepted, as in that case 



