92 



NATURE 



[September 19, 1912 



has taken the matter up himself, and publishes an 

 abstract of Avanzini's work in The Aeronautical 

 Journal for July- The work in question was pub- 

 lished in the Memorie deW Istituto nasionale italiaiio 

 at Bologna early last century, and deals with experi- 

 ments on the relations between the velocity of a plate 

 in still water, the angle of attack, the position of the 

 centre of pressure, the density of the fluid, the length 

 and breadth of the plate. The paper is illustrated by 

 copies of the original diagrams, and contains experi- 

 mental data. There are, however, several errors 

 which require correction in the formulae. 



The annual report of the results of sight tests in 

 the Mercantile Marine, for the year ending on Decem- 

 ber 31, 1911, just published as a Parliamentary paper 

 (Cd. 6370), shows a slight increase in the percentage 

 of failures, both in form and in colour vision, over 

 the returns of the preceding year. 7309 candidates 

 were examined, with 117 failures in form vision, none 

 of whom were re-examined, and with 192 failures in 

 the first examinations for colour vision, of whom 56 

 passed on re-examination. This gives a percentage 

 of 189 failures in colour vision, as against i"5i in 

 19 10, and is the largest proportion yet recorded. The 

 methods of testing employed were the same as in 

 1910, the recommendations of the Departmental Com- 

 mittee appointed in that year not having yet been 

 acted upon. Those recommendations included the 

 substitution of a dark brown test skein for the deep 

 red at present in use, and the employment of a special 

 lantern, designed by the committee, for all candidates. 

 Preparations are being made to carry these alterations 

 into effect at the earliest possible time, and they seem 

 calculated to meet all reasonable objections to the tests 

 hitherto employed, .^n article on the report of the 

 committee appeared in Nature of July 4 (vol. Ixxxix., 

 P- 453)- 



Vol. v. of the Journal of the Municipal School of 

 Technology, Manchester, a record of investigations 

 published by the staff and students during 191 1, ex- 

 tends to nearly 300 pages. Like its predecessors, it 

 shows the unique position as a centre of research in 

 applied science occupied by the Manchester School 

 amongst the technical schools of this countrv. Three 

 of the nineteen papers reprinted deal with pure science, 

 and of them that by Prof. Gee and Mr. .^damson, 

 describing a neat and simple "dioptriemeter " for 

 measuring the focal lengths of lenses bv the deviation 

 produced, may be specially mentioned. Of the tech- 

 nical papers, the most important are that on electricitv 

 meters, by Messrs. Ratcliff and Moore, read before 

 the Institution of Electrical Engineers, that on the 

 electrical theory of dyeing, by Mr. W. Harrison, who 

 finds in the theory explanations of manv facts pre- 

 viously not interpreted, and that on boiler economics 

 by the use of high gas speeds, by Prof. Nicholson, 

 who shows how boilers may be reduced in size about 

 30 per cent, without any diminution in their steam 

 production. The journal is printed in the printing 

 crafts department of the school, and its execution does 

 credit to that department. 



I'mihh the title of " Geostatic Funiculars,'^ Prof. 

 A. F. Jorini, writing in the Rendiconfi del R. IstiUito 

 NO. 2238, VOL. 90] 



lombardo, xlv., 13, gives a solution of the problem 

 presented by a cylindrical tunnel subjected to earth 

 pressure, the surface of the superincumbent earth 

 being horizontal. 



Prof. C. M-W.-vix's papers on aeroplane stability in 

 the Rez'ista de la Sociedad matemdtica cspaiiola con- 

 clude with the July number. The author succeeds in 

 satisfying the conditions for longitudinal but not 

 lateral stability. The latter failure is due to the 

 character of the systems of surfaces assumed in the 

 investigation. Tf the author had studied a system 

 furnished witli two vertical auxiliary surfaces or fins, 

 he would have had no difficulty in satisfying the neces- 

 sary conditions, and it is to be hoped that readers of 

 the paper will not accept the conclusion that all 

 systems of planes are laterally unstable. 



In a paper read recently by Mr. Edwin O. Sachs, at 

 the New York International Congress on the testing 

 of materials, the author directs attention to the very 

 small amount of scientific testing of reinforced con- 

 crete which has been carried out in Britain. Our 

 public institutions have been very remiss, for there 

 is practically nothing to place beside the elaborate 

 researches carried out by engineering professors in 

 the public laboratories of the United States, Germany, 

 and France. The author thinks that it is almost 

 hopeless to e.xpect our Government or our engineering 

 colleges to pay now any attention to the matter, so 

 that we can only look for a continuance of the efforts 

 of private bodies, such as the professional societies 

 intimately concerned. 



OUR ASTRONOMICAL COLUMN. 



G.^le's Comet, 1912a. — The comet discovered by 

 Mr. Gale on .September 8 is apparently becoming 

 brighter and travelling northwards. A second tele- 

 gram from Kiel states that it was observed at Santiago 

 on September 11, when its position at 7h. 4g'2m. 

 (Santiago M.T.) was : — 



R..'\. = i3h. 54m. 2'4s., decl.=33° 10' 50" S. 

 Comparing this with the position at the time of 

 discovery, we see that the comet moved about 4° 15' 

 to the east and 3° 20' northwards in a little more than 

 two and a half days. In a telegram announcing the 

 discovery. Renter's .Agency gave the magnitude as 6 ; 

 the Santia^go observer reports it as 5, so that there 

 is a possibility of the comet becoming a more or less 

 conspicuous object in our evening sky. When dis- 

 covered, the comet was about half-wav between 9 and 

 1 Centauri, and is apparently travelling towards the 

 neighbourhood of a Librae; this region now sets at 

 about 7 p.m. 



In the Astronomische Nachrichteu (No. 4601) Herr 

 Prager describes the object seen at Santiago as round, 

 diameter 2', magnitude between 3 and 6, nucleus, no 

 tail. 



The Totm. Sour Eclipse of Octomer 10. — From 

 The Observatory, No. 452, we learn that the eclipse 

 party from Greenwich, consisting of Messrs. Edding- 

 ton and Davidson, with Mr. J. J. .\lkinson as a 

 volunteer, left for Brazil on .\ugust 30. They expect 

 to make their observations from Christina, some 150 

 miles inland from Rio de Janeiro, and the programme 

 includes the direct photographv of the corona, the 

 photocraphy of the ultra-violet spectra of the corona 

 and chromosphere, and an attempt to secure mono- 



