December 30, 19 15] 



NATURE 



489 



of pack, and in the South Atlantic the ice-observations 

 by Dr. Bruce in the Scotia are not incorporated. These 

 latter might conceivably be of direct importance to 

 merchant vessels ; the others could affect only explor- 

 ing ships. It is remarkable that while the extreme 

 limits of ice approximate to the parallel of 40° S. in 

 the Atlantic and Indian Oceans, records of icebergs 

 ire very few in the forties and fifties in longitudes 

 east of Greenwich. In the Pacific, where the ice 

 limits are further south, icebergs are numerous, as 

 they also are in the waters immediately to the east of 

 Cape Horn. The dimensions of some of the bergs 

 recorded by merchant ships suggest probable exaggera- 

 tions, but it would be impossible satisfactorily to edit 

 these data, and so they must stand as given. 



La Nature for December 4 has an interesting popu- 

 lar article on the methods of testing guns and ammuni- 

 tion, being the second article of a series on " Les 

 Laboratoires de la Guerre." The first subject dealt 

 with is the determination of the muzzle velocity of 

 projectiles, measured by the well-known Boulengd 

 chronograph ; then follows a description of the crusher 

 gauge and its use for measuring pressures in the gun 

 The apparatus in use in France for gauging the bore 

 of the guns for possible distortion on firing and measur- 

 ing the horizontal and vertical displacement after 

 firing are described and illustrated. The stability on 

 firing is a most important question, and is registered 

 by means of suitable points attached to the gun and 

 wheel axles which score directly on plates suitably 

 placed in relation to the movement to be traced. With 

 the latest Schneider guns it is stated that a glass of 

 wine placed on the rim of the wheel is not upset on 

 firing the gun. The velocity of recoil and return is 

 measured by means of the tuning-fork method, the 

 vibrations of the fork and travel of the gun being 

 recorded on a blackened bar fixed to the top of the 

 gun. The temperature attained on firing successive 

 rounds is estimated by the use of a series of fusible 

 crayons of chosen melting point to form a scale of 

 temperatures permitting measurement to 20° C. An 

 interesting feature of the article is the description of 

 the drastic tests to which field pieces are subjected. 

 At the Creusot factory four of the carriages are run 

 by electric power over a circular track of pavd ; at the 

 Schneider works the carriage is drawn by an engine 

 running alongside the test track over every conceiv- 

 able object likely to be met with in the field, various 

 road surfaces, ditches, railway lines, etc., and they are 

 also tested under horse traction. In dealing with pro- 

 jectiles the degree of fragmentation is considered, and 

 some illustrations given of the effect of shell fire on a 

 field battery and on a concrete wall. 



The Research Laboratory of the Eastman Kodak 

 Company at Rochester, New York, was organised in 

 1912, and in full working order early in 1913. Since 

 then Dr. C. E. K. Mees and the staff working with 

 him have published the results of their work in various 

 journals in this country and in America, and as it is 

 likely that many who are interested have not these 

 journals available, the company has just issued a 

 seventy-six page pamphlet, which contains abstracts of 

 all the scientific papers published by them during the 

 NO. 2409, VOL. 96] 



years 1913 and 1914. This step cannot fail to be appre- 

 ciated by those who are privileged to receive a copy. 

 Ther^ are three chief departments of the laboratory, 

 namely, chemistry, physics, and photography. The 

 pamphlet contains abstracts of twenty-two papers — 

 none chemical. Perhaps the chemical work done is 

 too intimately connected with the factory to justify its 

 publication. The abstracts give the chief results ob- 

 tained, and hence are useful without reference to the 

 originals. The greater number of the abstracts are 

 intimately connected with photography, and deal with 

 such matters as sensitometry, colour processes, bright- 

 ness of image, resolving power, etc., and some are 

 of more general interest. L. A. Jones has investigated 

 the utility of the standard acetylene lamp designed 

 by Mees and Sheppard, which consists of an acetylene 

 flame from a single jet and a diaphragm in front that 

 isolates about 5 mm. of it. It is simple, requires but 

 little attention, and is otherwise satisfactory. The 

 "Colour of Illuminants," by L. A. Jones, "The Axial 

 Chromatic Aberration of the Human Eye," by P. G. 

 Nutting, "The Visibility of Radiation," by P. G. 

 Nutting, a.re other papers which will appeal to many 

 who may care but little about photography. 



The second series of Science Reports of the T6hoku 

 Imperial University, vol. iv.. No. 4, contains a fifth 

 communication " On the Chief Constituent of Japan 

 Lac," by Rik6 Majima. This is a remarkable com- 

 pound, of a type that has not hitherto been found in 

 nature, namely, an aromatic compound, with a very 

 long aliphatic side-chain. The compound itself, which 

 is described as urushiol, is unsaturated ; but it can be 

 reduced to a saturated compound, hydrourushiol, to 

 which a definite formula can now be assigned, namely, 

 1:2: 3-CjH3(OH)2(Ci5H3,). The aromatic nucleus is 

 of the familiar pyrocatechol type; but it contains a 

 normal pentadecyl group attached as a long " straight- 

 chain " to the nucleus in the position immediately 

 adjacent to the two hydroxyl groups. The position of 

 the double-bonds in the side-chain of the unsaturated 

 urushiol is still undetermined. 



An account of the construction of some laboratory 

 electric furnaces, given in an article in Nature of 

 December 16, contained a sectional diagram and a 

 description of a single-tube furnace. The purpose of 

 the article was mainly to explain the principles fol- 

 lowed in the design of such furnaces ; and Messrs. 

 Gallenkamp and Co., Ltd., wish it to be understood 

 that the diagram, which was drawn by the contributor 

 of the article, should not be taken as an actual repre- 

 sentation of the details of their patented furnaces. 

 The specification of their laboratory furnaces of various 

 types, with particulars as to performance, advantages, 

 and prices, will be found in a special pamphlet (List 

 No. 65) recently issued by Messrs. Gallenkamp, who 

 will send a copy to science teachers and other workers 

 engaged in instruction or research upon application 

 being made to them at 19/21 Sun Street, Finsbury 

 Square, London, E.C. 



A CATALOGUE of books on Africa, just issued by Mr. 

 Francis Edwards, High Street, Marylebone, deserves, 

 attention. In its classified lists are many books from 

 the library of Mr. Charles Cowen, editor of the Cape 



