6o8 



NA TURE 



[April 26, 1894 



basis of all classifications. Many attempts of improving it have 

 from time to time been made, but the problem of obtaining a 

 more perfect nomenclature still remains, to a great extent, un- 

 soiverl. When such an accomplished bibliographer as Dr. 

 Hellmann undertakes the reproduction of a work, we may be 

 sure that he will tell us all that can be known about it, and 

 few persons can read his introductory remarks without learn- 

 ing something. Comparatively few copies appear to have 

 been reprinted from the Philosophical Magazine, and Dr. 

 Hellmann points out that the first part of the text was set up 

 afresh, as some of the lines do not exactly agree ; also, that 

 some small omissions were made in the separate copies of 

 1803 which have been added to this new edition. In 1832 a 

 second edition was issued without plates; but in 1849 L. Howard 

 appears to have drawn a new set of cloud pictures, and these, 

 although not considered to be equal to the first, were included 

 in the third edition, published in 1865. Many other details of 

 great interest are given by Dr. Hellmann, to which we cannot 

 now refer. We may mention that the plates only are actual 

 facsimiles, while the type of the text is as nearly as possible 

 like that of the original work. 



The additions to the Zoological Society's Gardens during the 

 past week include a Slow Loris {Nycticebiis tardigradiis) from 

 Malacca, presented by Captain Spalding ; two Sooty Manga- 

 beys {Cercocebus fuliginosus, 9 ? ), an African Civet Cat 

 ( Viverra civetta), two Royal Pythons {Python regius) from West 

 Africa, presented by the Rev. Canon J. Taylor Smith ; two 

 Crested Porcupines {Hystrix cristata) from South Africa, pre- 

 sented by Mr. Adrian Vander Byl ; a Water Vole {Arvicola 

 ainphihius) British, presented by Colonel L'Estrange ; a Buzzard 

 Buteo vulgaris) British, presented by Colonel C. B. Rashleigh ; 

 a Raven {Corvus corax) British, presented by Miss P. L. 

 Graham ; two Pin-tailed Sand Grouse {Pterocles alchata, i ? ) 

 South European, a Black Gallinule {Limnocorax niger) from 



East Africa, two- -Moorhens {Gallinula sp. inc.) from 



Madagascar, presented by Mr. H. H. Sharland ; four Swain- 

 son's Francolins {Francolimis sioainsoni), a Delalande's Lizard 

 {Nuc)-as delalandii), a Rough-keeled Snake {Dasypeltis scabra) 

 from South Africa, presented by Mr. J. E. Matcham ; a Chim- 

 panzee {Anthropopithectis troglodytes, i ) from West Africa, a 

 Lioness {Felis led) from India, deposited ; a Chimpanzee 

 {Antkropopitheczts troglodytes, 9 ) from West Africa, a White- 

 backed Trumpeter (Psophia leucoptera), a Short-tailed Parrot 

 {Pachynits brachyurus) from the Upper Amazons, a Blackish 

 Sternothere {Sternotharus subniger) from Madagascar, pur- 

 chased ; two Barbary Wild Sheep {Ovis tragelaphus, ? ? ) born 

 in the Gardens. 



OUR ASTRONOMICAL COLUMN. 



Four New Variable Stars. — Prof. E. C. Pickering 

 announces {Astr. Nach. 3225) that four new variable stars 

 have been discovered by Mrs. Fleming from the presence of 

 bright hydrogen lines in photographs of their spectra taken in 

 connection with the Henry Draper Memorial. The first of these 

 is a star in the constellation Sculptor, having the co-ordinates 

 R.A. oh. io'4m. Deck -32° 36'. The range of variability of 

 this star is from magnitude 65 or 6'6 to lo'o, and the period 

 366 days. The second star is Arg-Oeltz 16121, in Scorpius, its 

 exact position being R.A. i6h. 50'3m. Decl. - 30° 26'. Therange 

 of variability is from 7-3 to il'6 magnitude, and the period is 

 278 days. The star B.D, + I°"34i7, in the constellation 

 Ophiuchus(R.A. I7h. I4'5m. Decl.-I- 1° 37') is the third of the 

 variables discovered, the range in this case being from magni- 

 tude 8'5 to I2'5, and the period 348*4 days. The fourth star is 

 B.D. + 4'^'4250, in the constellation Aquila (R.A. igh. 46'5m. 

 Dec!. + 4° 13'). Its period is about a year, and at the last 

 maximum on August 12, 1893, its photographic magnitude was 

 9*5. At a minimum it becomes fainter than the twelfth magni- 

 tude. 



NO. 1278, VOL. 49] 



Speed of Perception of Stars. — When working at the 

 Etna Observatory during a high wind. Prof. Ricco noticed how 

 the pole star and its companion appeared to change their mutual 

 distance at every vibration of the telescope. The phenomenon 

 was not observed on the following night, which was calm, but 

 could be reproduced by shaking the telescope. The pole star 

 appeared in every case to move more rapidly than its companion. 

 This observation has been communicated to the Societa degliSpet- 

 iroscopisti Italiani, and connected with Prof. Schaeberle's inves- 

 tigation of the difference of personal equation between bright and 

 faint stars observed in transit. Schaeberle estimated the appa- 

 rent retardation of faint stars ato'02 sec. per magnitude. Prof. 

 Ricco proposes to redetermine this by measurements of stellar 

 distances by the micrometer as compared with the transit instru- 

 ment. That the colour may have a determining influence is 

 shown by the fact that when a spectrum is displaced rapidly at 

 right angles to its length, the more refrangible portions appear 

 to lag behind. 



Elements and Ephemeris of Gale's Comet {b 1894). — 

 The following elements and ephemeris are given in a supple- 

 ment to Astronoinische Naclirichteii, No. 3225 : — 



T = 1894 April 13-75 G.M.T. 



CO = 324 19 i 



Q, = 206 15 • Mean Eq. i894'o. 



^■= 87 15) 



q = 0-9849 



Ephemeris for Greenwich Midnight. 

 1894. R.A. P.D. 



O / o / • 



April 26 ... loi 38 ... 124 23 



30 ... 115 22 ... 109 31 



The comet is increasing in brightness, and on April 30 it will 

 be 6 "05 times brighter than at the time of discovery. 



A Mistaken Cometary Discovery. — From a note by Prof. 

 Krueger in Astronomische Nachrichten, No. 3224, it appears 

 that the object seen by Mr. Holmes on April 9, and afterwards 

 announced as a new comet, is really ihe nebula No. 6503 in 

 the New General Catalogue. 



THE 



INSTITUTION OF MECHANICAL 



ENGINEERS. 



T^HE meeting of the Institution of Mechanical Engineers was 

 -'- held last week in the theatre of the Institution of Civil 

 Engineers, on Thursday and Friday evenings, April 19 and 20. 

 The chair was taken by the President, Prof. Alexander B. W. 

 Kennedy, F.R.S. Two papers were read at the meeting: the 

 first, " On ^the Grafton High Speed Engine," by Mr. E. W. 

 Anderson ; and the second, " On Fluid Pressure Reversing 

 Gear," by Mr. David Joy. The President's address was, how- 

 ever, the chief feature of the meeting, and to this we shall 

 mainly confine our report, more especially as it would be diffi- 

 cult to give an adequate description of the mechanical devices 

 upon which the two papers were founded without somewhat 

 elaborate illustrations. 



After the usual formal proceedings. Prof. Kennedy read his 

 address. It had been expected that in consequence of the lead- 

 ing part the Pr.esident has recently taken in the development of 

 electrical engineering that the address would deal largely with 

 that subject, and in this respect the result proved to be in ac- 

 cordance with general expectation. The address pointed out 

 that practical electrical problems divided themselves into three 

 main sections, in which electrical energy is used, respectively : 

 firstly, for lighting; secondly, for power; and thirdly, for physico- 

 chemical processes. The third section, which relates to the 

 deposition of metals, the reduction of chemical compounds, &c., 

 was one in which the President had not had experience, but he 

 had no doubt that there was a great future before it. In this 

 section he also included the application of electricity to heating, 

 and said it was to be hoped that there being so many compe- 

 tent workers engaged in the study of this subject, success would 

 soon attend their efforts. The commercial problem of produc- 

 ing the heat sufficiently cheaply to allow of its general use was 

 yet to be overcome. Remembering, however, that something 

 like 95 per cent, of all the energy that goes to incandescent 

 lamps appears only as heat and not as light, there would seem 

 to be an ample opening here for another " thermal storage ' 



