46 



A'A TURE 



[November ri, 1909 



fulfil, namely, (i) to determine the maximum, as well as 

 the mean stress, on the material tested ; (2) to be easily 

 adapted to specimens of varying diameters ; (3) to be easily 

 adapted to specimens of varying length ; (4) to measure 

 accurately strains of at least one hundred-thousandth part 

 of an inch ; (5) to be of reasonable expense. The results 

 •of a large number of tests made with the instrument are 

 given. These tend to prove that copper, aluminium, and 

 other non-ferrous metals have very varying elastic proper- 

 ties, and it is consequently impossible to establish any 

 •definite law for elastic failure. It appears, however, that 

 elastic failure always does take place according to a law 

 which approximates closely to the maximum shear-stress 

 theory. 



In an article on the development of modern road surfaces 

 in the Journal of the Franklin Institute for October, Mr. 

 \\'. H. Fuhveiler divides the methods of applying tar into 

 three general heads : — (a) Brushing with a hot coating of 

 coal-tar and dusting it lightly with sand ; in general use 

 In France, (b) Painting the surface by machine and dust- 

 ing with sand ; in general use in England, (c) Coating the 

 surface with a fairly heavy coating of hot tar or tar com- 

 pounds, and then covering with a light coat of screening, 

 the surface being finally rolled. The latter is the general 

 system adopted in America, and seems to be better adapted 

 to the rougher surface of American roads. A refined grade 

 of tar, considerably heavier than that used in France or 

 England, is used, having more body and greater binding 

 properties, and the coating applied is about twice as heavy. 

 .\ light coating of clean gravel or fine stone chips is then 

 put on instead of sand and rolled, thus renewing the wear- 

 ing surface and filling the voids better than can be done 

 by the use of sand. The treatment produces deeper penetra- 

 tion and more lasting effect, and succeeds best on macadam 

 roads. It is practically mud-proof, absolutely free from 

 load dust, apparently proof against very heavy motor 

 traffic, and is the most satisfactory for American conditions. 

 The cost is higher than that of the French and English 

 inethods. 



An interesting pamphlet dealing with water-hammer in 

 steam pipes has been issued by Mr. C. E. Stromeyer, 

 chief engineer of the Manchester Steam Users' Association. 

 .\ccording to the Board of Trade reports, water-hammer 

 I1.1S been the cause of about 120 steam-pipe explosions. 

 Mr. Stromeyer finds that nearly one-half of these have been 

 •due to the absence of drain-cocks on steam pipes, or to 

 their injudicious use. A large number, chiefly on steamers, 

 have been produced by admitting steam into pipes con- 

 taining water. Others have occurred when water was 

 admitted into steam pipes, or when steam condensed in 

 them. Steam being admitted through valves on which 

 water was resting, injudicious opening of valves having 

 sLeam and water on both sides, and injudicious manipula- 

 tions of steam valves, whereby plugs of water have been 

 set in motion, have all contributed to swell the total of 

 explosions. Mr. Stromeyer considers it inadvisable to lay 

 down at present definite rules for the design of pipe 

 arrangements in general, having been led to this conclusion 

 by the fact that draining arrangements, designed to obviate 

 explosions, have caused the majority of accidents, and also 

 ■because in many cases of complicated pipe arrangements 

 the water-hammer may often be attributed to any of the 

 above-mentioned causes. Mr. Stromeyer complains of the 

 insufiiciency of the official reports of explosions having 

 given him much difficulty in arriving at definite con- 

 clusions. 



Mr. W. B. Clive, of the University Tutorial Press, Ltd., 

 has published a second edition of " First Stage Sound, 

 NO. 2089, VOL. 82] 



Light and Heat." The book has been revised and re- 

 written by Dr. R. W. Stewart, who has introduced a course 

 of experimental work. The price of the book is as. 



In connection with the Winnipeg meeting of the British 

 -•Xssociation last August, the Manitoba Free Press published 

 a series of illustrated biographical sketches of the president, 

 Sir Joseph Thomson, F.R.S., the presidents of the sections, 

 the evening lecturers, and the general officers of the 

 association. These biographies have now been re-issued in 

 pamphlet form at the price of 50 cents. Copies of the 

 booklet can be obtained from Mr. A. V. Thomas, c/o 

 Manitoba Free Press, Winnipeg, at yid. each. 



We have received a copy of the second part of vol. xiii. 

 of the Transactions of the Leicester Literary and Philo- 

 sophical Society. The booklet contains abstracts of lectures 

 delivered before the society, the report of the council, and 

 the annual reports of the sections of the society presented 

 at the annual general meeting in May. The report states 

 that the balance of the fund raised in connection with the 

 visit to Leicester, in- 1907, of the British Association has 

 been voted to the council of the society for investment as 

 the nucleus of a fund, the interest accruing from which is 

 to be devoted in a manner to be decided by the council, 

 annually, or at such times as the council may determine, 

 to the development of local scientific knowledge, including 

 that bearing upon the industries of the town. A cheque 

 for 80/. has been received, and the council has appointed 

 a special committee to consider and report as to the best 

 means of applying the money in furtherance of the object 

 intended. 



OUR ASTRONOMICAL COLUMN. 

 Astronomical Occurrences in Novemrer: — 

 Nov. II. loh. 27m. Mercury in conjunction with the Moon. 

 (Mercury 1° 21' S.). 

 16. i6h. 27m. Venus in conjunction with the Moon. 



(Venus o' 6' S. ). 

 ,, igh. cm. Vesta in conjunction with ihe Moon. 



(Vesta 1° 15' N.). 

 I7- 5^- 39'"- Uranus in conjunction with the Moon. 

 (Uranus 5° o' N.). 



22. loh. iim. Mars in conjunction with the Moon. 



(Mars 4' 26' N.). 



23. I3h. 15m. Venus in conjunction uith Uranup. 



(Venus 2° 33' S.). 

 ,, I4h. 53m. Saturn in conjunction with the Moon. 



(Saturn 1° 32' N.). 

 „ 7h. 3gm. Minimum of Algol (/3 Persei). 

 26. 2oh. S5m. Eclipse of the Moon, partly visible at 



Greenwich. 

 ,, 4h. 28111. Minimum of Algol. 



29. 23h. 22m. Neptune in conjunction with the Moon. 

 (Neptune 4° 14' S.) 

 Re-discoverv of Winnecke's Comet (igogd). — A tele- 

 gram from the Kiel Centralstelle announces that 

 Winnecke's comet 'was re-discovered at the La Plata 

 Observatory, Argentina, on October 31. Its position on 

 that date' at 8h. 14.1m. (La Plata M.T.) was 

 I7h. iim. 5i-6s., —27° 18' 43", and its magnitude was 

 about 100 ; this position lies a little to the south-west of 

 S Ophiuchi. .According to Prof. Hillebrand's elements, the 

 perihelion passage took place on October 40 (G.M.T.). 



Hallev's Comet. — According to a note in the November 

 number of the Observatory^ Halley's comet is steadily 

 increasing in brightness, and ten minutes' exposure, pre- 

 sumably with the Greenwich 30-inch reflector, gives a 

 strong image. Reproductions of photographs are given in 

 the Observatory (Greenwich, September 23), Knowledge, 

 and the Astrophysical Journal (Verkes Observatory, 

 September 16, 17, 24, and 26). The Observatory (No. 415, 

 p. 435) also gives an ephemeris for April and May, 1910, 

 the time of perihelion passage being taken as April 19-65 



