January i8, 191 2] 



NATURE 



3^7 



13-5° and 25-8° respectively. Once in F"ebi'uary 

 was recorded (which is not unusual on the 



pressure and temperature. The regularity of other pheno- 

 mena also made it possible to obtain mean values for them 

 also, rainfall being the most uncertain. The mean pressure 

 (altitude 2370 metres) is : — winter, 577-5 mm. ; summer, 

 573"3 '■ )''"'> 5755 ; temperature for same periods, 14-2°, 

 20-6°, 17-5^ C. Mean annual humidity, 50 per cent. ; rain- 

 fall. 452 mm. The daily range of temperature is very 

 large, c-prciall}' in winter. The mean minimum in winter 

 is about 4-8°, mean temperature at 2h. p.m., 24° ; in 

 summer, 

 -0-4 



plateaux I; the absolute maxima at 2h. p.m. often exceed 

 30°, and a reaumg of 33^ has been recorded by the maxi- 

 mum thermometer. In 1883 the rainy period lasted from 

 ^March to August, with a complete break in June (which 

 |Was abnormal). During thunderstorms rain and hail 

 showers are often heavy (on July 23, 52 mm.). From May 

 to October north and north-east winds, January to April 

 south winds, were most prevalent ; the latter are mostly 

 Hght morning breezes; all the stronger winds are northerly, 

 and sometimes reach storm force. 



The Scientific American for December 23, 1911, contains 

 an illustrated one-page article on Sir Joseph Thomson, by 

 Dr. P. Phillips. It gives a short sketch of his education, 

 and describes how Sir Joseph, after his appointment as 

 professor of experimental physics at Cambridge when a 

 " mere boy," gradually built up the present school of re- 

 searcii and made the Cavendish Laboratory famous 

 throughout the world. A clear picture is drawn of the 

 great master amongst his students ; and at this stage the 

 author cannot keep up the formal references to " Sir J. J. 

 Thomson," but lapses into the old affectionate "J. J." 

 The portrait which illustrates the article shows Sir Joseph 

 in a \' i\ characteristic attitude. 



'//((' Central for December, 191 1, has an interesting 

 article oil a new aluminium industry, by Mr. A. V. Hussey. 

 It describes the methods used in the manufacture of large 

 vats and tanks from sheet aluminium. The joints, which 

 are generally butt joints, are welded by means of an oxy- 

 hydrogen blow-pipe, which melts the metal at the joint, 

 while a special flux dissolves the oxide formed and allows 

 the two edges of metal to run together. When the joint 

 has 1). . n trimmed and hammered it is as smooth as the 

 rest <>l I lie sheet, and under test proves as strong as the 

 uinvork'd p.irts. The development of the industry has 

 a[)iiaiinil\ h.cn in the hands of old students of the City 

 and (uiilil- Collei^,. throughout. The editors appeal to old 

 student'- Inr ihiir views as to the values of individual por- 

 iums 1)1 ill." tiirei' \i :ii>' course at the college. These mav 

 l)e of ^j|, ( ial valie , a^ it is not often that those taught 

 get .-111 .i]i])niuiiiii\ ol expi . ^-,in- themselves. W'e ini-t the 

 aiixief. . M,r-,-,,(| by tile edilui- .•!•.; to the future- ul the 

 '>l'l ^ \ -<M intion, ovviiie uj the numerous changes 



iiii^'' ■ -, |,.,iie at South Kcii.siiigtun, will prove to be 



Uill.MM:.!. .1. 



*>i'Mi '.! \'. -■]-.-, li.i'.i |j/-.ii ill u'.i- |(ir a lono ij,,,,-, but 

 111' gradual' (I tint was .-liwax-- iiarmw in inoport imi in its 

 leit.^th. ii is only about ei-hi,-, a iminllls a-.i llial |)|-. 

 <e,'.i:M;:j M-ested the lis.. ,,| •• \\,-ilo..^s( r.'.ii-," ami 



"lid \y prndui < i\ \tv east in- pi-n e 1 1 1 ed 

 ,, ■ iA luai >!e i IS ,,l -las. ihal luucll at 



<>'i'- ' :i-liilN- s,.p .Ii,. ,,p|„,,ite edge. 



■'A- made ,. , > i 111. ley Ijy Messrs. 



.1 recMit m.-iiiu; of th- Royal Photo- 

 Reiiwii k described sm-i nf di,.;.- i.^os, 

 '• tif tile wedge-sci' is 



llf..i 

 SJl .11 



.\'.'. - 



_'Uj, VOL. 88] 



wide, that is, square or approximately square, and this 

 allows of another plate upon which, for example, a 

 graduated tint has been produced for testing purposes, being 

 rotated upon the wedge-screen. If the gradation of the 

 plate is exactly the same as that of the screen, and they 

 are brought face to face in reversed positions, the two 

 together give a uniform tint. Then, knowing the values of 

 the screen, the gradation of the plate is known also. 

 But if the two gradations are not equal, by isolating 

 a strip and rotating the one upon the other it is possible 

 to get the visible strip of equal density throughout its 

 length ; and Mr. Renvvick showed the exact relationship 

 between the angle of rotation and the comparative steep- 

 ness of gradation of the screen and the plate, whether the 

 plate is steeper or less steep than the screen. The one 

 screen plate, therefore, permits of the measurement of the 

 steepness of gradation of any plate, the sere-en with its 

 known values being the standard, without the us, uf anv 

 photometric instrument, except perhaps in a secondary 

 sense and of the simplest description, to determine the 

 equality of the density of the observed strip. 



In connection with the application of photography to the 

 detection of adulteration, the current (Januarv) number of 

 The World's Work contains some interesting reproductions 

 of photomicrographs, by Mr. Ernest Marriage. Of these, 

 the following may be specially mentioned : — pure apple jam ; 

 "improved" strawberry and gooseberry; "improved" 

 raspberry and currant ; pure blackcurrant jam ; b!a( k- 

 currant " improved " with fruit jelly. In all these s,ini])l. s 

 of so-called " improved " jams the characteristic apple- 

 cells are clearly discernible. The photographs are pub- 

 lished in illustration of an article by " Home Counties " 

 entitled " Unsophisticated Jam." 



The Bulletin of the St. Petersburg Academy of Sciences, 

 part XV. of 191 1, contains an important paper, bv Prof. 

 Walden, of Riga, on formamide as an ionising solvent. 

 This solvent has the property of imitating in a remarkable 

 degree the physical characteristics and constants of water. 

 In the present paper its behaviour as a solvent in cr\(iscopic 

 measurements and the electrical conductivity of its s,,lii- 

 tions are described. It is shown that when binarv salts 

 are used as solutes, solutions are obtained for whieli the 

 coetlicient of ionisation may be even greater than in wali 1 . 

 Moreover, the cryoscopie .md th-- elecirieal nieasiuements 

 agree in giving concordant rigurcs for iIt eoi iVk ieiu of 

 ionisation over a range of dilutions fiom 5 ki mo lin. s 

 per gram-molec iile. Sirone organie ai 

 tribromoacetic Ai'\t\. dn nei, lu,\\e\,i, i., , 



any marked extent wleii dis 

 found that siareh dissciU-d 

 cular weigiit .M--645, corn 

 (^-'t.H,„0,),, and tliat its ^ 



4- iSi) '. ( 'asiin Lj.ivi- .1 nu 

 spccilie nil ati )i \ pow er 1 eo 



Till- U, ■:■!!,■ ■■riirniir ,/, ^ s, :,),, < ^ i.| 

 contains an ;irliile \<\ \] . i.aiiH.iie ,.11 

 the Cryogenic l..ilior.itoiy of I.eyd.n. 



givnn of th'> niilhiids iis.d ill lieu, t 

 .-\|.-nsi\-.' seal.', and 1 \s . 1 di,.::iaii! 

 lie- ,-irr.-illi;'iiii'iil nl lii- appaia;;. - 

 .allied out uith lie- li' Ip <d liqiiid I 



helium includes: (1) .1 (l.:..ei;.iii 

 pressure of neon (20 .mnosp 

 the triple point (3-; . > .. 

 the constants of at 



mof;i!s- .'It low temp- ........ -. .-v 



that lie 1 . si-iaiie.- ul eolii .-ind of 11 



. il 111 lorinai 

 torniaiiiid.- ; 

 indiiie wiih 

 ilie rol;aoi\ 

 iilar \\.-i-lil 

 .sN 



sueii 

 innisri 



. . il 



111 \\(ll 



an. I 



loll. 



k of 



Hint Is tli.-i.- 

 I'lini on an 



'■ le sluiW 



1 . I ellth 



I .1 .lK|ui.l 



nil 



dim 



