6/8 



NATURE 



[February 20, 191 



lie on the same curve, taking account, of course, 

 of the scale of the model. AH the values of the 

 vertical components for the aeroplane fall exactly 

 upon the curve for the model, and five out of seven 

 for the horizontal components likewise, the other 

 two showing- but slight difference. The paper 

 contains other results obtained in this new labora- 

 tory from which much may be expected in the 

 future. 



In his paper 2 M. Gandillot makes frequent c;i!ls 

 upon the experimental results obtained by M. 

 Eiffel to support the mathematical analysis he 

 gives of the action of bodies moving through the 

 air and the thrust of aeroplane propellers. He 

 considers the air as an elastic medium in which 

 disturbances are propagated according to well- 

 known laws. The mass of air acted upon by a 



-Discbarge end of the Ve 



uLe(.\uleil bbor.-ito 



plane surface moving through it may be calculated 

 by these considerations, and the deductions are 

 supported by M. Eiffel's results. Thus a plane 

 surface moving at a constant velocity at a known 

 gradient acts upon a mass of air greater than the 

 volume swept through, as is .shown by the fact 

 that the force necessary to move the plane is 

 greater than would be accounted for by displace- 

 ment. In the light of the experiments of M. Eiffel 

 on propellers in a current of air, the discussion of 

 the action of propellers during llight is interesting, 

 especially the law connecting speed of flight with 

 angular velocity of propeller. This mathematical 

 summary is a valuable work taken in connection 

 with the researches at the Champ de Mars and 

 Auteuil. R. S. B. 



Par Maufcc Gandilbt. 



NO. 2260, VOL. 90] 



THE WHEAT SUPPEY OF GREAT BRITAIN. 



'T'HE recent announcement by Mr. R. H. Rew 

 -L that this country produces about one-half 

 of its own food lends interest to the volumes of 

 statistics periodically issued by the Board of 

 Agriculture, setting forth the respective amounts of 

 agricultural produce raised at home and imported 

 trom abroad, and the home production of agricul- 

 tural produce. Even those who professed to be 

 experts in the matter were not prepared to find 

 that so much of our food was home-grov^n. There 

 is no doubt that the wheat statistics had been 

 responsible for the misconception. Only about 

 one-fifth of our wheat is supplied by the British 

 farmer, the rest all coming from abroad. It had 

 been too hastily assumed that the other imports 

 of food supplies 

 worked out in the 

 same proportion. 



In the latest 

 figures published 

 in the Journal of 

 the Board of Agri- 

 culture (No. 6, 

 iqi2), it is shown 

 that the home crop 

 amounted to more 

 than 8 million 

 quarters for the 

 previous season 

 (11)11-12). Al- 



though this is far 

 below the lo mil- 

 lion quarters 

 raised in 1885, it 

 is, nevertheless, 

 the highest crop 

 obtained for many 

 years, a highly 

 satisfactory result 

 on which agricul- 

 turists are much 

 to be congratu- 

 lated. The" total 

 im ported was 

 roughly 27^ mil- 

 lion quarters, 

 which came most from India, next from Canada, 

 followed by the United States, Argentina and 

 Australia, and least (among the principal 

 countries) from Russia. Oiie of the most 

 remarkable de\elopments has been the Indian 

 supply. So recently as 1908-9 India came rather 

 a bad fourth on the list of wheat-supplying 

 countries, Canada third, and the Argentine and 

 the United States respectively first and second. 

 But the Indian export made a big jump up in 

 lOog-io, and a further one in 1910-11, and it 

 n-aintained this new high level in 1911-12. 



So much admirable work has been done at 

 i'usa on the production of Indian wheats for the 

 British market, and so much interest has been 

 aroused among the more progressive cultivators, 

 thai we m.av confidently expect India to maintain 

 a high position among wheat-producing countries. 



