32 



NATURE 



[March 14, 191 J 



Prof. Inglis in New Zealand; Sefior Augusto Villa- 

 nueva in Chile; Prof. Guye in Switzerland; and Prof. 

 H. Kamerlingh Onnes in Holland. 



Subscriptions should be sent either to the Lord Mayor 

 at the Mansion House, or to the Hon. Treasurer, 

 Ramsay Memorial Fund, University College, Gower 

 Street, London, W.C.i. 



AVRORA AND MAGNETIC STORM OF 

 MARCH 7-8, 



THE auroral display of Thursday last attracted 

 much attention, partly because it coincided with 

 an air-raid upon London. The northern sky was 

 lighted up with a crimson glow both before and during 

 the raid, which started shortly after ii p.m.; and the 

 appearance was thought b\' an observer at Folkestone 

 to be due to a distant fire. Sir Napier Shaw informs 

 us 'that the Meteorological Office has received reports 

 of aurora observations from Lerwick, Stornoway, Esk- 

 dalemuir, Donaghadee, Liverpool, Clacton, and South- 

 end. He has favoured us with the follow- 

 ing account, iby Dr. C. Chree, of the large 

 magnetic disturbance recorded at the Kew Ob- 

 servatory between 9 .p.m. on Thursday and 5 a.m. 

 on the following morning. Mr. A. Lander has sent 

 us photographic traces of movements in declination 

 recorded at Canterbury during Thursday and Friday. 

 Thursday's trace was remarkably even until shortly 

 after 9 p.m., when the magnetic storm began. It is 

 possible that the disturbance was a repetition, after 

 three 27-day intervals, of the large magnetic storm of 

 December 16-17, 1917. There was a very considerable 

 disturbance on January 12 at the end of the first 27-day 

 interval, and a minor disturbance at the end of the 

 intermediate interval in February. 



Dr. Chree writes : " A magnetic storm of no great 

 duration, but very considerable amplitude, was re- 

 corded at Kew Observatory on the night, March 7-8, 

 1918. It began with a ' sudden commencement ' at 

 about 9h. 10m. p.m. on March 7. The largest move- 

 ments occurred in the early morning of March 8, be- 

 tween midnight and 5- a.m., but smaller oscillations 

 persisted for some time after the latter hour. The 

 ' sudden commencement ' Avas especially prominent in 

 horizontal force (H) ; after a small, sudden fall there 

 was a sharp rise of fully 607. The corresponding 

 movements in declination (D) consisted of an oscilla- 

 tion of about 4', the first movement being to the west. 

 The range shown on the D trace was about 51', the 

 extreme easterly and westerly positions being reached 

 at 2.20 a.m. and 4.16 a.m. respectively on March 8. 

 Between i.ii a.m. and 2.20 a.m. of the same day 

 there was a movement of 36' to the east. The range 

 on the H trace was about 2407. A very rapid down- 

 ward movement commenced about 2.3 a.m. on March 8, 

 the fall during the next thirty minutes amounting to 

 fully 185 7. After 5 a.m. on the same day there were 

 only short-period oscillations in H of moderate size ; 

 but up to 10 a.m. the element remained depressed by 

 fully 707 as compared with its value on the previous 

 day before the storm." 



MILITARY AERONAUTICS. 



'T^HE recent night raids on Paris by squadrons of 

 -•• Gotha machines brings the question of defence 

 against such raids before us, and adds much interest to 

 an article by Lieut. Jean-Abel Lefranc, who, writing in 

 the Revue Scientifique. gives an excellent review of 

 the development of German bombing machines, of 

 which the latest type is the Gotha. He also surveys 

 the various methods of defence thait have been adopted, 

 NO. 2524, VOL. lOl] 



particularly against night raids. His article is full ot 

 interesting details, of which it is only possible to quote 

 a few, and to recommend those who are interested to 

 read the original in the Revue Scientifique for Febru- 

 ary 16. A detailed description of the Gotha machine 

 is given, the overall weight being quoted as 84,000 lb., 

 and the weight of bombs carried as about half a ton. 

 The speed is given as ninety miles per hour, and the 

 height to which the machine can rise after discharging 

 its bombs is 20,000 ft. M. Lefranc also states thai 

 the Gotha is likely to be replaced by a "Gotha Riesen- 

 flugzeug," having four motors, and a span of about 

 130 ft. The "large Friedrichshafen Gotha" which wa> 

 captured in one of the Paris raids can scarcely be one of 

 these later machines, as it only had two motors of 

 250 h.p. each. The extreme difficulties of accurate bomb- 

 ing by night are commented upon, and the writer thinks 

 that the demoralisation of industry is a more importani 

 result of night raids than the actual damage done. 

 With regard to defence, camouflage, anti-aircraft guns, 

 and attack (by fighting machines are discussed, but 

 M. Lefranc considers that all these methods are very 

 ineffective, and that the best method of defence is to 

 attack and destroy so far as possible the enemy's 

 aviation centres. Commenting on extreme measures, 

 such as total abolition of artificial lighting at night, 

 he thinks they are a vain sacrifice to public 

 opinion, and may even be a detriment to the Services. 

 M. Lefranc concludes his well-written article with a 

 picture of the bombing machine of the near future, 

 pointing out that a machine of 1000 h.p., carrying two 

 tons of explosives, is within the reach of modern 

 design. 



The National Geographic Magazine for February, 

 published by the National Geographic Society, of 

 Washington, U.S.A., should be read by all who are 

 interest^ in the development of aviation and in the 

 pant which America is playing in the struggle for 

 aerial supremacy. The whole of this attractive issue 

 is devoted to matters of aeronautical interest, and the 

 photographs which illustrate the articles are especially 

 good. Three of the articles deal directly with American 

 activity, and are entitled "America's Part in the Allies" 

 Mastery of the Air," "Building America's Air Army,'" 

 and "The Futureof the Airplane." The second of these 

 merits special attention, and is beautifully illustrated 

 by no fewer than forty-three photographs. The first 

 section deals w^ith the actual construction of American 

 machines, and the manufacture of their parts is de- 

 scribed in some detail. Some really magnificent photo- 

 graphs follow, showing machines in flight and views 

 obtained from aeroplanes, and the article concludes 

 with a description of the training of aviators and the 

 tests which they must pass ibefore being pronounced 

 expert pilots. The magazine also contains a number 

 of descriptive articles giving the experiences of aviators 

 in various countries, which make very interesting read- 

 ing, but which it is impossible adequately to sum- 

 marise in a short notice such as the present. 



THE PRODUCTION OF FUEL OIL AND 

 COAL-GAS. 



MUCH attention lias been devoted recently to de- 

 veloping the home production of fuel oil, the needs 

 of the Navy and difticulties of transport rendering this 

 imperative. Several well-informed articles have ap- 

 peared in the Press, and the subject was dealt with in 

 Nature of February 28 (p. 506). Opinion is divided 

 among experts as to the probability of finding petrol- 

 eum in any quantity in this country, but Lord Cow- 

 dray, who has been so closely associated with the 

 remarkable developments of the Mexican and other 



