December 21, 191 1] 



NATURE 



255 



approval, and as they are frankly based on the recent 

 French competition rules, and call in some instances for 

 more difficult tests, it is felt that the winning machines 

 will represent the best productions at present obtainable. 

 The prizes are divided into two classes : (a) For aeroplanes 

 made in any country (open to the world), first prize, 4000/. ; 

 second prize, 2000L (6) For aeroplanes manufactured 

 wholly in Great Britain, except the engines (open to British 

 subjects), first prize, 1500Z. ; two second prizes, lOooL each ; 

 three third prizes, 500Z. each. There are, in addition, con- 

 -olation awards of looZ. each for ten machines wnich 

 undergo all tests and do not receive a prize, and the War 

 Office is to have the option of buying any of the prize 

 machines at loooZ. apiece. The chief conditions to be 

 fulfilled are as follows : — The machine, which must be a 

 two-seater fitted with dual controls, must rise without 

 damage from long grass, clover, or harrowed land in 100 

 yards in a calm, carrying a live load of 350 lb. in addition 

 to instruments and oil and fuel for 4I hours' running. In 

 rising, the height of 1000 feet must be reached in five 

 minutes, and it must fly for three hours continuously, of 

 which time one hour must be passed at an altitude of 

 4500 feet. Before landing, a glide of not more than 1000 

 feet will be required, and the angle must be not less than 

 I in 6. The landing must be made without damage on 

 any cultivated ground, including rough plough. Among the 

 desirable attributes of the aeroplane are mentioned a 

 silencer to the engine, flexibility of speed, and an engine 

 capable of being started from on board. 



It is with much regret that we see the announcement of 

 the sudden death of Prof. Andrew G. Ashcroft, of the City 

 and Guilds (Engineering) College, South Kensington, S.W., 

 at fifty-two years of age. Prof. Ashcroft was a student at 

 University College, London, and at the conclusion of his 

 student career he was attached to the staff of the Engineer- 

 ing School. For some time he was engaged in construc- 

 tional engineering work at the Alexandra Palace, and in 

 other practical work of a similar nature. He returned to 

 the Engineering School of University College, London, to 

 act as assistant to Prof. T. H. Beare and Prof, (now Sir) 

 Alexander Kennedy. Whilst acting in this capacity he 

 lectured on engineering subjects at the East London 

 College, then the People's Palace. At this period of his 

 career, coincident with the recognition of the importance 

 of technical education, he was appointed head of the 

 Woolwich Polytechnic, and his work in this position 

 showed that he was a shrewd and capable organiser. He 

 left Woolwich to take up the work of assistant professor 

 of civil and mechanical engineering at the Central Tech- 

 nical College, London. Prof. Ashcroft was keenly 

 interested in the subject of the strength of materials, and 

 was an expert in the measurement of small strains. 

 Amongst other instruments, he designed an extensometer 

 for measuring elastic strains ; a delicate cross-strain 

 " asurer for the determination of Poisson's ratio; and a 

 iid-testing machine for small tension pieces with a 

 'ially delicatf autograpiiic recorder. His written con- 

 ibutions to various societies include papers on properties 

 malleable iron, instruments of precision, and the 

 asurement of air supply to internal-combustion engines. 

 )f. Ashcroft was a member of many societies, and took 

 active interest in the welfare of each one of the 

 merous social clubs which exist at the college where he 

 nked. He was universally popular with the students, 

 • uid the engineering profession is the poorer for the loss 

 of so attractive a personality. 



A SERIOUS explosion, resulting in injury to eighteen 

 officers and men, occurred on December 12 during certain 



NO. 2199, VOL. 88] 



trials which were being carried out on board H.M.S. Orion 

 at Portsmouth. From the newspaper accounts it appears 

 that official tests of one of the dynamos were in progress 

 when the explosion took place. The explanations put for- 

 ward attribute the accident to the ignition of inflammable 

 vapour given off from the oil used as a lubricant of the 

 dynamo. One suggestion is that the production of vapour 

 was due to overheating of the bearings : this would imply 

 either that the lubricant was unsuitable or that it was not 

 properly applied. Whether in this particular case the ex- 

 planation is the true one or not, it seems at least probable. 

 Lubricating oils are generally composed of high-density 

 petroleum products, used either alone or mixed with a 

 proportion of vegetable or animal oil. Numerous varieties 

 are made to suit different types of machinery. For each 

 type, of course, it is important to choose the appropriate 

 lubricant. As regards inflammability, it is well known 

 that petrol and ordinary petroleum oil for burning give 

 off vapour at relatively low temperatures, but it is prob- 

 ably not so well recognised that at higher temperatures 

 some lubricating oils may do the same. In fact, a deter- 

 mination of the flashing point, or at least a proof that the 

 oil does not " flash " below a given temperature, is usually 

 required in deciding upon the suitability of certain kinds 

 of mineral oil for use as lubricants. 



The annual Christmas course of juvenile lectures at the 

 Royal Institution will begin on Thursday next, December 

 28, at three o'clock, when Dr. P. Chalmers Mitchell will 

 deliver the first of six lectures on " The Childhood of 

 Animals." 



At the recent annual meeting of the Yorkshire Numis- 

 matic Fellowship, held at Leeds, Mr. T. Sheppard, of the 

 Municipal Museum, Hull, was elected the president for the 

 year 1912, and editor of the society's Proceedings. 



A JOINT meeting of the Institution of Mining and Metal- 

 lurgy and the Canadian Mining Institute will be held at 

 Toronto on March 6, 1912, and the following days. The 

 meetings for the reading and discussion of papers will 

 occupy three days, March 6, 7, and 8. The annual dinner 

 of the Canadian Institute will be held on March 8, and 

 on March 9 an excursion to the mining districts of Cobalt 

 and Porcupine will be arranged, provided a sufficient 

 number of the members of the English institution wish to 

 visit those localities. Further details of the arrangements 

 may be obtained from the secretary of the institution, Mr. 

 C. McDermid, at Salisbury House, London, E.C. 



In proposing the toast of " The Institution of Mining 

 and Metallurgy " at the annual dinner of the institution, 

 held on December 15 at the Savoy Hotel, Sir Alfred Keogh 

 announced that the Bessemer Memorial Committee will, in 

 January, hand over to the Royal School of Mines the 

 laboratory which it has presented to the Imperial College 

 of Science and Technology. Mr. Sulman, in responding to 

 the toast, said that the world's production of gold in the 

 form of standard metal since 1880 has exceeded 

 i,ooo,ooo,oooZ. sterling, more than one-half of which has 

 been won from mines within the British Dominions. The 

 British capital involved in metalliferous mining, apart from 

 coal and iron, during the past twenty-five years exceeds 

 900,000,000?. sterling. During the past four years there 

 has been subscribed as working capital for metalliferous 

 ' mining, outside coal and iron, above 4,500,000?. sterling. 



! It is well known that the late Mr. J. R. Mortimer, the 



I Driffield antiquary, was an authority on the prehistoric 



i and other earthworks of East Yorkshire, and during the 



I past half-century be made a careful survey of all that 



