May 9, 1918] 



NATURE 



191 



i^ rrage. The week with the greatest deficiency of 

 nperature is the week ending April 20, when the 

 an was 40-4°, with a deficiency of 6-9°; during this 



A«ek the rainfall at Greenwich measured 179 in., 

 which is 02 in. more than the average for the whole 

 month. In London, at Tulse Hill, in a Stevenson's 

 -creen, the maximum thermometer only rose to 60° 

 01- above on three days in April, and the highest tem- 

 perature was 63°; whilst in March there were seven 

 such warm days, and the highest temperature was 

 •69°. April this year was peculiarly sunless, and this, 

 coupled with the low temperature, kept vegetation 

 throughout the month greatly at a standstill. 



The first of a series of articles descriptive of the 

 Jiiachinery of the S.S. Wuhty Castle appears in 

 Engineering for May 3. This, the first seagoing 

 vessel fitted in this country with steam turbo-electric 

 propelling machinery on the Ljungstrom system, ran 

 her trials on the North-East Coast last week. In 

 the Ljungstrom turbine the flow of the steam is radial, 

 and the arrangement differs from other turbines, in 

 •which fixed and moving blades alternate, in that both 

 ■sets of blades revolve in opposite directions. Hence 

 ■a high relative speed can be obtained without excessive 

 shaft speed. In this ship there are two turbo-alterna- 

 tors, each developing 625-kw. three-phase .current at 

 650 volts, 60 cycles per second, at 3600 revolutions 

 per rninute. These supply current for two main 

 induction motors, coupled to the single propeller shaft 

 through double helical gearing. These motors are 

 together capable of delivering 1500 shaft h.p. con- 

 tinuously at sea with a propeller speed of about 76 re- 

 volutions per minute, and also of driving the 

 ship ahead or astern at full power. The auxiliary 

 machinery is for the most part electricallv driven. 

 The boilers are fitted with, Schmidt superheaters, and 

 supply steam at a temperature of 625° F. The Ljung- 

 strom turbine has been proved to have a high efficiency, 

 and Sir William Beardmore has taken the initiative 

 in this country in its marine applications. 



In Prof. H. C. H. Carpenter's presidential address 

 to the Institute of Metals reference was made to the 

 work of the Corrosion Research Committee, which is 

 Investigating the corrosion of brass marine condenser 

 tubes by salt water. A laboratory specially designed 

 and equipped for the work has been installed in the 

 metallurgical department of the Royal School of 

 Mines, and the experimental plant has been removed 

 from Liverpool to the Southwick power station at 

 Brighton, and is being run under strictly practical 

 conditions. It has also been rendered possible for 

 the comrnittee to arrange that the problem should be 

 attacked in the laboratory ab initio with pure metals 

 corroding under the simplest conditions, and this 

 should greatly enhance the value of the work being 

 done. Prof. Carpenter also sketched in outline the 

 most suitable educational course for the metallurgical 

 engineer, and emphasised the point that the training 

 cannot be wholly undertaken at a technical school or 

 university. On completing his college course and 

 entering works, it should be the function of the works 

 to find out what special aptitudes the student pos- 

 sesses. He should have sufficient time to become 

 acquainted with the practice of each of the operating 

 ■departments, to find his feet, and to acquire the works 

 atmosphere. A discerning management will have little 

 difficulty in judging how best to utilise the services 

 of such a man after this probationary period, during 

 which he should be paid, at any rate, a living wage. 



An interesting article appears in the Fortnightly 

 Review for May under the combined authorship of 

 Mr. Claude Grahame-White and Mr. Harry Harper. 

 The title is " Sovereignty of the Air and its Relation 



NO. 2532, VOL. lOl] 



to Civil Aerial Transport," and the authors discuss 

 the conditions which should be adopted for the regula- 

 tion of air traffic after the war. Three plans are 

 considered: the air mav be completely free to all • 

 it may be under the sovereignty of the country over 

 which It lies; or a combination of these is possible 

 by malcing the air free to all only above a specified 

 ^[^"l''-. }^ }^ pointed out that if war could be 

 abolished by mternational consent, a free air would 

 be the best solution. It is, however, fairly obvious 

 that, for at any rate some years after the declaration 

 of peace, the nations will be forced to take strong 

 defensive measures in the air, and the only solution 

 of the problem rendering this possible is a complete 

 sovereignty of the air. The authors are of the opinion 

 that commercial aeronautics will make great advances 

 in the near future, and that the rapid inter-communi- 

 cation possible by the use of aircraft will do much 

 to foster the development of friendlv sentiments 

 among the nations, and so to advance progress 

 towards the goal of universal peace. They suggest 

 also the desirability of a universal language to facili- 

 tate international relations in general, and this is 

 certainly a point which cannot be overlooked. The 

 whole question of international relations after the war 

 is one of absorbing interest, and the article under 

 discussion is worthy of perusal by those whose 

 thoughts turn to the aeronautical side'" of such 

 relations. 



At the annual general meeting of the Society of Glass 

 Technology, held at Sheffield University on April 17, 

 Mr. Frank Wood, the president, compared the position 

 of the glass industry to-day with that before the 

 war. Dealing with various sections, Mr. Wood said 

 that the quality of British table and decorative ware is 

 supreme, but owing to competition the output is almost 

 negligible. Given three years' freedom of action, the 

 position of the manufacturers would be unassailable. 

 The plate- and window-glass trade is developing, and 

 the outlook for optical glass is hopeful, but it is very 

 necessary that the country .should be rendered inde- 

 pendent of foreign supplies of the latter; similarly 

 with chemical glass, electric bulbs, and pressed ware, 

 in which good progress has also been made. The 

 production of bottles and jars — the largest section — is 

 in a very healthy position, due to the introduction of 

 new machinery. The president also stated that with 

 united action amongst masters and men of all sections 

 he has every confidence in the future of the industry. 

 He then referred to the raw materials used by the 

 industry, giving statistics and discussing the degrees 

 of purity required, and concluding with some interest- 

 ing remarks on devitrification. The contents of tank 

 furnaces are subject to devitrification on a large scale; 

 this is known as "dogging." A certain amount of 

 "dog" serves to protect the tank-bottom, but in excess 

 it gives rise to difficulties which seriously affect out- 

 put. The formation of "dog" may be checked by 

 increasing the proportion of alkali or of alumina in 

 the batch. However, the addition of alkali, besides 

 increasing the attack on the sides and roof of the 

 tank, reduces the durability of the resultant glass, 

 whereas the addition of alumina, with less attack on 

 the tank, gives a more durable and tougher product. 



In response to the wishes of the American refrigera- 

 tion industries, the Bureau of Standards at Washington 

 has undertaken to redetermine the thermodynamic pro- 

 perties of ammonia, and three papers have recently 

 appeared in the Bulletin of the Bureau, by Messrs. 

 N. S. Osborne and M. S. Van Dusen, on the specific 

 heat of liquid ammonia, on the heat which must be 

 given to the liq lid to keep its temperature constant 

 when the pressure to which it is subjected is changed. 



