DISCOVERY 



A MONTHLY POPULAR 

 JOURNAL OF KNOWLEDGE 



Vol. II, No. 14. FEBRUARY 1921. 



PRICE Is. NET. 



DISCOVERY. A Monthly Popular Journal of Know- 

 ledge. 



Edited by A. S. Russell, M.C, D.Sc, 4 Jloreton 

 Road, O.xford, to whom all Editorial Communications 

 should be addressed. 



Published by John Murray, 5o.\ Albemarle Street, 

 London, W.i, to whom all Business Communications 

 should be addressed. 



Advertisement Office : 16 Regent Street, London, 

 S.W.I. 



Annual Subscription, 12s. 6rf. post free; single numbers, 

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Binding cases for Vol. 1, 1920, are now ready. Price 

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Editorial Notes 



The possibilities of a trans-Pacific flight has been 

 discussed by two writers in a recent number of the 

 periodical Aviation. A look at the map will show how 

 much longer a flight from, say, California to Japan 

 is than one from Canada to England. There are 

 several likely routes that might be tried in attempting 

 to make such a flight. There is, of course, direct flight 

 from America to Asia over about 4,500 miles of sea. 

 A halt might be made, however, at a suitable inter- 

 mediate spot such as Honolulu in the Sandwich Islands. 

 In this case the direct water-stretches would be re- 

 placed by two of about 2,100 and 3,400 miles. A 

 third possible route would be to fly round the Ameri- 

 can and Asiatic coasts, the only stretch of sea to be 

 flown over then being the short distance across Bering 

 Strait. This would involve a flight over a distance 

 from 6,000 to 8,000 miles, depending upon where the 

 flight commenced and terminated. 



***** 



At the present time the record flight of a lighter- 

 than-air machine is that of a Zeppelin during the war 

 which flew 4,000 miles in 100 hours, and of a heavier- 

 than-air machine that of the Vickers-Vimy which 

 crossed from Newfoundland to Ireland, a distance of 



about 1,900 miles. Considering both radius of action 

 and reliability, the authors consider that the rigid 

 airship stands first, the non-rigid second, and the sea- 

 plane third. They have worked out five principal 

 routes after considering the lengths of the stages of 

 the flight, meteorological conditions, and facilities for 

 landing, repair, and re-fuelling. Each route possesses 

 certain advantages as regards the type of machine 

 in which the flight is proposed. The conclusion of 

 the matter is that a rigid airship should be able to do 

 the flight to-day without a stop ; a heavier-than-air 

 machine, however, could do it also, but only by stop- 

 ping for re-fuelling. 



***** 



It is now well known that Colorado is the chief 

 place on the earth's surface at which radium may be 

 found. The other and better-known sources, namely, 

 the mines of Bohemia, Saxony, and Cornwall, contain 

 small quantities of ore compared with the amount 

 found near Denver. The ore there is called carnotite, 

 and has been mined for many years for the substance 

 vanadium (a constituent of certain steels) which it 

 also contains. The size of the deposits varies from a 

 few pounds to many tons, and altogether in the area 

 explored there is estimated to be about 100,000 tons 

 of ore. The quantity of radium in this mass may be 

 calculated from the percentage of uranium (about 

 1-5 per cent.) which it contains. It is about 15 ounces 

 avoirdupois, or 425 grams. This may not seem a 

 great amount, but it is about 425 times more than 

 most research-workers have ever seen or handled. 

 Radium is one of the few things which has not ad- 

 vanced very much in price since 1914, but its advance 

 in the twelve years before the war was so great that 

 it may have felt it had already done quite enough in 

 that particular way. In igo2 the price was 5s. a 

 milhgram — i.e. /250 per gram — next year it was £300 

 per gram, and in 1904 £1,000. The present price is 

 about £25,000. In spite of this the demand for it is 

 steadily increasing. It is to this American source of 

 supply that research-workers, hospitals, and all who 

 need racUum must turn for the material itself ; it is 



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