November 23, 191 1] 



NATURE 



121 



the more so as the disturbance proceeded from the some- 

 what low latitude of 20° S. 



The marine turbine speed-reducing gear fitted by the 

 Westinghouse Company, of Pittsburg, to the United States 

 collier Neptune is described in The Engineer for 

 November 17. This is a modified form of the Melville- 

 Macalpine gear with double-helical pinion and spur wheel. 

 The power transmitted is 4000 ; the pinion keyed to the 

 turbine shaft runs at 1250 revolutions per minute, and the 

 -crew shaft at 130 — a reduction of nearly 10 to i. The 

 pinion shaft is not carried in rigid bearings, but is borne 

 in a long sleeve, which is provided with three hydraulic 

 pistons above and three below. The movement from the 

 ( entral position is trifling — two or three thousandths of an 

 inch — but the liquid correction gives the gear a certain 

 amount of elasticity, reduces shock and noise, and conduces 

 to the sweet running of the gear. The Neptune has given 

 great satisfaction on its trials. 



With the view of ascertaining the resistance of rein- 

 forced concrete strong-rooms to attack by oxy-acetylene 

 i>Iow-pipes, tests were recently made on a slab prepared 

 Ijy the Indented Bar and Concrete Engineering Company, 

 of \\'estminster. The results are described in The 

 Engineer for November 17. The oxy-acetylene blow-pipe 

 was applied to the slab for twenty-four minutes, at the end 

 of which period, after much raking out of the resulting 

 ;*lass formed by the fusion of the sand, and accompanied 

 L>y a deafening roar from the blow-pipe, a hole 3-5 inches 

 in diameter was made through the slab. Whenever a steel 

 bar was met the metal-cutter, i.e. a stream of pure oxygen 

 directed on to the white-hot steel, was brought into action, 

 and the steel instantly fused away. The concrete was the 

 material which gave the trouble, the metal-cutter being 

 [)Ovverless to act upon it. The same thickness of steel of 

 any grade could not have resisted the metal-cutter longer 

 than about four minutes. The test slab was 6 inches 

 thick ; 055 cubic foot of oxygen and 045 cubic foot of 

 acetylene were consumed in the test, which clearly is 

 strongly in favour of reinforced concrete as contrasted with 

 steel. 



A COPY of the Year Book for 191 1 of the Indian Guild 

 of Science and Technology has been received. The object 

 of the guild is to cooperate in promoting the knowledge 

 and application of pure and technological science in India 

 with a view to the improvement of the methods of economic 

 production and the amelioration of the sanitary condition 

 of tho people. Prof. Smithells, F.R.S., is the general 

 president of the guild ; and among the list of patrons we 

 notice the names of Sir Henry Roscoe, F.R.S., Sir William 

 Ramsay, K.C.B., F.R.S., and Prof. O. N. Witt. The 

 year book runs to 135 pages, and contains an oflicial re- 

 port of the annual general meeting, held on December 19, 

 [910, of the activities of the various sections, and the 

 speeches at the annual dinner. In addition, a number of 

 scientific articles, many of them concerned with pressing 

 Indian problems, are in"luded. Altogether the guild, which 

 is only in the third year of its existence, has entered upon 

 a career of great usefulness. 



Messrs. Newton and Co., 3 Fleet Street, B.C., have 

 just issued a supplementary list of lantern-slides, in which 

 several sets of slides of scientific interest are included. 

 Among these subjects are remarkable examples of achieve- 

 ments of photography, pictures taken by Prof. R. W. 

 Wood with ultra-violet and infra-red rays, photographs of 

 snow crystals taken by Mr. W. A. Bentley, wild How. r^, 

 glaciers, and other scenes in Switzerland, ;in<l :in hi^ > 

 tural hygiene. 



NO. 2195, VOL. 88] 



OUR ASTRONOMICAL COLUMN. 



The Spectrum of Brooks's Comet, 1911c. — With the 

 three-prism slit spectrograph (No. iii.) and a small 

 objective-prism spectrograph of 10 cm. focal length, both 

 attached to the Pulkowa 30-inch refractor, Prof. Belopolsky 

 secured several photographs of the spectrum of Brooks's 

 comet during October. Eight hours' exposure with the 

 slit spectrograph on October 4, 5, and 6 showed the bands 

 473 MM and 431 fi/j. clearly, and others faintly; in each 

 case the several maxima in each band were measured, and 

 the wave-lengths are given to six figures. Measures of 

 the radial velocity of the comet gave +1$ km., agreeing 

 with the ephemeris. 



With the smaller spectroscope monochromatic images of 

 the comet were found at 560, 516, 473, 405, and 388 n/x, 

 each image being sharply defined on the red side ; special 

 measures gave the values 388-36 fifi and 387-52 fifi. Bands 

 in the continuous spectrum extended from 420 to 421 fifj. 

 and from 402 to 405 nfi. On October i the bands were 

 equal in intensity, but on October 10 that at \ 388 was 

 the brightest ; this band only gave a faint trace of the tail 

 {Astronomische Nachrichten, No. 4535). 



The Chemical Unity of the Cosmos. — In the current 

 number of Scientia Prof. Fowler has an interesting article 

 in which he sums up the evidence showing the chemical 

 unity which exists among all the bodies of the visible 

 universe, so far as our present means permit us to examine 

 them. Kant and Laplace suggested such a unity ; but it 

 was not until Kirchhoff and Bunsen, in 1859, supplied the 

 key which opened up to us celestial spectrum analysis 

 that the suggestion could be practically tested. Several 

 factors still interfere in many cases with the proof of 

 absolute coincidence of wave-length in comparing radia- 

 tions in different spectra, but Prof. Fowler believes that 

 all celestial spectra will sooner or later come within the 

 scope of laboratory reproduction. Most of the strong lines 

 in the solar spectrum are already origined, and the sun 

 has been shown to take its place in an orderly sequence 

 of stellar forms. Then, again, the study of the various 

 elements, under varying laboratory conditions, initiated by 

 Sir Norman Lockyer, has provided us, so far as the main 

 variations in celestial spectra are concerned, with terrestrial 

 parallels for the stellar departures from the sun's spectral 

 features. 



Sun-spots and Flocculi in 19 10. — In addition to the 

 values for December, 1910, No. 12, vol. i., of the Boletiti 

 Mensuel del Observatorio del Ebro contains the risumi of 

 the solar and meteorological observations made during 

 1910. The spot areas were low throughout the year, and 

 no spots were recorded at all in August, September, and 

 December. The reduced area for spots, in both hemi- 

 spheres for the whole year, was 165 millionths of the sola- 

 hemisphere, and for flocculi the analogous value was 40: 

 hundred-thousandths, the ratio between the two being 24-3. 

 Taking the hemispheres separately, the values for the 

 northern was 42, and for the southern 123, millionths fo: 

 spots, and 114 and 287 hundred-thousandths for flocculi. 

 The mean heliographic latitude of spots was loi, and for 

 flocculi 10-2. During the year there were 301 groups of 

 flocculi occurring with spots and 525 occurring without, 

 and the tabulated summary shows that those groups occur- 

 ring with spots were decidedly of a more compact character 

 than those occurring without. 



ASTROGRAPHIC CATALOGUE, PERTH (W.A.) SECTION. — In 



the preparation of the International Astrographic Cata- 

 logue the section dec— 31° to -41° was allotted to the 

 Perth Observatory, West Australia, which has just pub- 

 lished the first volume of results. The complete measures 

 will occupy thirty-six volumes ; and the present issue, th.- 

 first to be completed, is vol. iv. The method of work i- 

 briefly explained by Mr. Cooke, but a general introduction 

 will appear later. It is believed that the faintest stars 

 shown on the centre of the Perth plates are of about 

 mag. II-5, those at the extreme corners 10-5; and th- 

 present volume contains the measures of the rectangulai 

 ( (MJiIinates and magnitudes of 13,636 star images between 

 R.\. iSh. to 24h. on plates with centres in declination 

 -32°- 



