ii6 



NATURE 



[March 25, 1920 



other plants, economic and wild, in the Orient, where 

 it is now widely distributed, though in 1900 the 

 disease was practically unknown. 



The Jourqal of the Franklin Institute for February 

 contains the address on "Sound-ranging as Practised 

 by the United States Army during the War" delivered 

 at the meeting of the physics section of the institute in 

 October last by Prof. A. Trowbridge, of Princeton Uni- 

 versity. The methods used were those developed by our 

 own Sound-ranging Section, and are known to many 

 of our readers. They depend on the differences of the 

 times of arrival of the sound of a gun at six stations 

 near the gun, and are both sensitive and instru- 

 mentally very accurate. The residual errors are 

 almost all due to uncertain meteorological conditions 

 at the time of observation. As compared with other 

 methods of location of enemy guns, the American 

 experience is summed up in the following- numbers : — 

 During a three weeks' rapid advance sound-rangers 

 accounted for 21 per cent., and flash-rangers for 79 per 

 cent., of the guns located. During the two following 

 weeks, when the advance had been checked, sound 

 was credited with 54 per cent., and light with 46 per 

 cent., of the locations. These records are charac- 

 teristic, and show that the Sound-ranging Section 

 required a little longer to get into efScient action 

 than the Flash-ranging Section. 



We have received a copy of the first volume of the 

 Chemical Age (June-December, 1919). Besides more 

 or less ephemeral matter, the volume contains a 

 number of important articles possessing a permanent 

 interest. Among these may be mentioned "The 

 Chemist's Place and Function in Industry," by Sir 

 Robert Hadfield; "Recent Developments in Indus- 

 trial Catalysis," by Dr. H. S. Taylor; "The Com- 

 mercial Synthesis of Organic Compounds from 

 Acetylene," by Mr. M. J. Marshall; and "The Syn- 

 thesis of Ammonia," by Dr. E. B. Maxted. A useful 

 feature of the journal is the weekly account, with 

 illustrations, of patent literature ; this keeps the 

 reader early in touch with advances made both in 

 this country and abroad, and will be of value to the 

 industrial chemist and the chemical engineer. It is 

 satisfactory to find that the promising standard of the 

 early numbers is well maintained in the later issues. 



It is more than a hundred years since Sir 

 Humphry Davy first described his wire-gauze safety 

 lamp to the Roj'al Society (1818). The chief use of 

 the lamp has, of course, been in the coal-mining 

 industry. Danger of gaseous explosions also exists, 

 however, in various chemical works where inflam- 

 mable liquids are dealt with, a frequent cause being 

 the use of naked lights in the repair or cleansing of 

 large holders in which such liquids have been stored. 

 Even at some distance from the liquid a naked light 

 may be dangerous, as vapour given off may render 

 the atmosphere capable of propagating flame. Atten- 

 tion is directed to this fact in the Journal of the 

 Society of Chemical Industry (February 28) by Mr. 

 W. Payman, who advocates the use of some form of 

 safety lamp where artificial illumination is required 

 in such circumstances, and describes various forms 

 of lamp suitable for the purpose. 

 NO. 2630, VOL. 105] 



Engineers who have to solve problems based on 

 the properties of steam, and especially those connected 

 with steam turbines, will welcome a new alignment 

 diagram constructed by Mr. D. Halton Thomson, and 

 published in Engineering for March 5. The principal 

 jjart of the diagram is based on Callendar's equations 

 for the properties of steam, and by applying the prin- 

 ciple of duality Mr. Thomson has succeeded in produc- 

 ing an alignment diagram which represents not only the 

 simpler of the Cailendar equations, but also the others 

 not hitherto amenable to this treatment. The diagram 

 has scales showing (a) the total heat of superheated 

 or supersaturated steam, and also the total heat of 

 wet steam ; {h) the amount of superheat ; (c) the dry- 

 ness fraction; (d) the total entropy; (e) the hydraulic 

 efficiency for multi-stage turbines during superheated 

 or supersaturated expansion ; (/) the specific volume 

 of superheated or supersaturated steam, and also of 

 wet steam ; {g) the absolute pressure ; and {h) the 

 saturation temperature. An auxiliary scale gives the 

 relation of the heat drop and the steam velocity, and 

 the Wilson point is marked on the chart. A straight- 

 edge laid across the scales gives the whole of the 

 required properties at once. As an example of the 

 kind of complex problems which can be answered in 

 this way, we quote the following from the article : — 

 In a four-stage turbine the steam expands in thermal 

 equilibrium from 200 lb. per sq. in. absolute and 

 superheat 100° F. to 1-5 lb. per sq. in. absolute; 

 the stage efficiency is 0-65 and the reheat factor 1-045. 

 Required the pressure, specific volume, and quality 

 at the end of each stage. By no means the least 

 interesting part of the article is an appendix showing 

 the methods employed by Mr. Thomson in trans- 

 forming the equations to the form desired. 



Dr. Griffith Taylor, the Australian meteorologist, 

 delivered during the war courses of lectures on 

 meteorology to the Commonwealth Flying School and 

 at the University of Melbourne, and as a result he is 

 now publishing, through the Oxford University Press, 

 "Australian Meteorology, with Sections on Aviation 

 and Climatology." The volume will include chapters 

 on the studv of the weather chart, work at a small 

 station, the peculiarities of the Australian rainfall, the 

 special storms and hurricanes of Australia, actual pro- 

 cedure in upper-air research, the discussion of long- 

 distance forecasting and the application of meteorology 

 to aviation, etc. 



In the Veterinary Review for February (vol. iv.. 

 No. i) Mr. Fred Bullock contributes an instructive 

 article on the compilation of tiibliographies. Full 

 details are given of the proper manner of compiling 

 a bibliography, and a nurriber of examples of correct 

 and incorrect references to journals and other pub- 

 lications are given and criticised. 



Messrs. Crosby Lockwood and Son, 7 Stationers* 

 Hall Court, London, E.C.4, have just issued a new 

 select list of books published by them on chemical 

 technology. A copy will be sent to any reader of 

 Nature post free upon application to this well-known 

 firm of publishers of modern scientific, industrial, and 

 technical books. 



