174 



NATURE 



[May I, 1919 



The composition appears to be approximately 60 per 

 cent, nickel, 14 per cent, chromium, a little molyb- 

 denum, and the remainder iron. It is melted in 

 crucibles and poured into sand moulds. Its tensile 

 strength at air-temperature is 50,000 lb. per sq. in., 

 while at 1800° F. it is still 30,000 lb. It melts at 

 2800° F., and withstands repeated heatings to 1800° F. 

 and coolings without serious oxidation or diminution 

 of strength. It works well, and can be drawn into 

 wire. It is not acted on by chemicals even when 

 heated, and is already being freely used for the valves 

 and valve-seats of internal-combustion engines and for 

 domestic utensils. The possibility of using the alloy 

 in place of plumbago for crucibles is under investiga- 

 tion, and the results so far obtained are most en- 

 couraging. The field of usefulness of an alloy with 

 these properties is obviously extensive, and it is un- 

 fortunate that the Scientific American gives no hint 

 as to where the material can be obtained. 



In the Proceedings of the Indian Association for 

 the Cultivation of Science (vol. iv., part ii., 1918) Mr. 

 S. Banerji deals with the vibrations of elastic shells 

 partly filled with liquid. The problem here con- 

 sidered is chiefly of acoustical interest in relation to 

 the theory of " musical glasses." This class of 

 instrument consists of a series of thin-walled elastic 

 shells the gravest modes of vibration of which are 

 tuned to form a musical scale by partially filling them 

 with a liquid, and are excited either by strikmg or 

 by tangential friction on the rims. The principal 

 features of interest requiring elucidation are (a) the 

 dependence of the pitch of the vibration upon the 

 quantity of liquid contained in the vessel, and (b) the 

 mode of vibration of the liquid itself. These features 

 are discussed in this paper for the three cases in 

 which the elastic shell is respectively (i) a hemi- 

 spherical one, (2) a cylindrical one with a flat bottom, 

 and (3) a conical cup, these forms approximating 

 more or less closely to those used in practice. The 

 analytical expressions show that the motion of the 

 liquid is very marked near the margin of the vessel, 

 but is almost imperceptible near the centre and 

 at some depth inside the liquid. Numerical results 

 have also been obtained and tabulated, and the graphs 

 plotted, showing the theoretical relations between 

 the quantity of liquid in the vessel and the vibration 

 frequency. The lowering of pitch due to addition of 

 liquid is greatest when the vessel is nearly full. 



Messrs. Bernard Quaritch, Ltd., ii Grrafton 

 Street, W. i, have just issued a Catalogue (No. 352) 

 of second-hand books and periodicals which they 

 have for disposal. The 1700 odd works listed range 

 over many branches of literature, but the sections 

 relating to natural history and periodicals and trans- 

 actions of learned societies will appeal more especially 

 to readers of Nature. In them we notice a set, with 

 supplement, of Gould's "The Birds of Australia," 

 FJwes and Henry's "The Trees of Great Britain and 

 Ireland," Sargent's "The Sylva of North America: A 

 Description of the Trees which Grow Naturally in 

 North America exclusive of Mexico," Butler's " Illus- 

 trations of Typical Specimens of Lepidoptera Hetero- 

 cera in the Collection of the British Museum," 

 R. Bowdler Sharpe's "Hand-list of the Genera and 

 Species of Birds," Edwards's "The Botanical 

 Register" (a set), and long runs of the Berichte of 

 the Deutsche Chemische Gesellschaft, the Quarterly 

 Journal of Microscopical Science, and the Proceedings 

 and Transactions of the Zoological Society of London. 

 The catalogue is published at is. 



The following books of science and education are 



announced for earlv publication : — " Euclid in Greek " 



(Book i.). Sir T. L. Heath, and "A Short Histoiy 



of Education," Prof. J, W. Adamson (Cambridge Uni- 



NO. 2583, VOL. 103] 



versity Press); "Practical Vaccine Treatment for the 

 General Practitioner," Dr. R. W. Allen {H. K. Lewis 

 and Co., Ltd.)', "George Westinghouse : His Life 

 and Achievements," F. E. Leupp {John Murray); 

 "Scientific Factory Management," Dr. A. D. Denmng 

 {J. Nisbet and Co., Ltd.); "Gas and Oil Engine 

 Operation," J. O'Kill {Sir Isaac Pitman and Sons, 

 Ltd.). 



OUR ASTRONOMICAL COLUMN. 



The April Meteors of 19 19. — Observations were 

 obtained at Bristol on the nights of April 18, 20, 21, 

 and 22, but the display was by no means a rich one. 

 The night of chief activity was April 21, when fourteen 

 meteors were recorded between 8h. 40m. and iih. 3sni. 

 G.M.T. Of these, nine were Lyrids and indicated a 

 radiant point at 272°-t-3o°. Several fine meteors were 

 observed on this night, and particularly at 9.30 and 

 9.40 G.M.T. The first of these appeared as bright as 

 Sirius, and slowly floated from 236°—!^° to 246° — 2° 

 in about 5 sees. This must have been a fine object as 

 seen from the eastern counties of England. The 

 second was one of the true April meteors, with a 

 bright streak, and moved swiftly from 297°+65° to 

 3i°+47i°. It was of about the same apparent magni- 

 tude as Jupiter. 



The Meteoric Shower of Halley's Comet. — The 

 celebrated comet of Halley has an accompanying 

 meteor system. The shower was discovered in 1870 

 by Capt. G. L. Tupman, and shown by Prof. A. S. 

 Herschel, a few years later, to exhibit a significant 

 resemblance to the cometary orbit. The meteors are 

 visible in the mornings of the first week in May, and 

 their flights are directed from a point near the equator 

 in R.A. 337° in Aquarius, and close to the stars 

 ^ and ri in that constellation. The meteors have not 

 been witnessed in the same splendour and abiindance 

 as those of November from Tem pel's and Biela's 

 comets, but they are individually very fine objects, 

 traversing long paths extending occasionally over half 

 the visible firmament, and worthy representatives of 

 the notable comet from which they are derived. 



The reappearance of this shower is now due, and 

 it is very desirable that a watch for its meteors should 

 be maintained on the next few mornings. We wai r 

 more data with regard to its duration, whether or 

 not the point of radiation moves eastwards, like that 

 of the Perseids, and what annual differences affect 

 the number of meteors appearing. Double observa- 

 tions of identical objects will be valuable as enabling 

 their heights and velocities to be determined. Th<? 

 materials already acquired affirm that the observed 

 motion is decidedly slower than that implied from 

 theory, and this is probably due to the resistance of 

 the atmosphere. The radiant does not rise until the 

 morning twilight is in evidence, and when a short 

 period onlv remains available for observation. 



Heis, so far back as Mav 2, 1848, witnessed a rich 

 display of streaking meteors, and this may quite pos- 

 sibly have been an early return of this system. 



Occultation of Stars by Venus. — Mr. Arthur 

 Burnet, honorary secretary of the Leeds Astronomical 

 Society, who has achieved success previously in pre- 

 dicting phenomena of this kind, writes to us from 

 France that the stars 79 Leonis, magnitude 5-^, and 

 B.D. + 2-2422*', magnitude 8-6, No. 6927 in the d'Abba- 

 dia Catalogue (1900), will be occulted by the planet 

 Venus on August i next as seen from certain places 

 in the southern hemisphere. Geocentric conjunction 

 of the planet with 79 Leonis will take place on 

 August id. 8h. 54m. G.M.T., and the occultation 

 may be seen from South America. Mr. Burnet com- 

 putes that the duration of the occultation as seen 

 from Rio de Janeiro will be about nine minutes. 



