4i6 



NATURE 



[November 24, 192 1 



herd having increased by 32 per cent., while the yield 

 per cow has also been greatly increased. At the 

 outbreak of war a larger quantity of food was being 

 produced than at any previous period. During the 

 war there was a setback in food production, the 

 amount of cereal food being increased, but other kinds 

 of food being markedly reduced. Whether the pre- 

 war standard of total output has been regained is 

 regarded as doubtful, but such facts as are accessible 

 point to the conclusion that the output of food has 

 been increased. Indeed, the agricultural land of the 

 country is capable of producing more food, for on a 

 large proportion of it the output is undoubtedly 

 lamentably deficient. 



"State Aid and the Farmer" forms the subject 

 of an interesting paper contributed by Mr. S. L. 

 Bensusan to the Fortnightly Review for September 

 last. At the end of the war agriculture was at the 

 summit of expectation, and the machinery required 

 for the big development foreshadowed by the Prime 

 Minister was gradually assembled. The passing of 

 the Agricultural Act left the farmers under certain 

 obligations to the State and to his employees, and in 

 receipt of guarantees to enable him to face foreign 

 competition in wheat and oats. The general p>olicy 

 of the Minister of Agriculture was to further the 

 development of research, to protect the industry from 

 diseases, to organise the agriculture of each county, 

 and at the same time to make conditions as free as 

 possible to encourage enterprise. But the Agricul- 

 tural Act is now in large part repealed, and the 

 farmers' position is not an enviable one. Not only 

 have all costs increased, but the farmers have also 

 to contend with the grave difficulties introduced by 

 the Labour Bill and the new hours of labour. 

 Farmers have a deep sense of grievance against the 

 Wages Board, and they tend to take up an attitude 

 towards the farm labourer that will lead to wide- 

 spread disturbance throughout the rural area. It is 

 of the utmost importance that farmers and labourers 

 should meet in a spirit of justice and right endeavour, 

 and should seek by co-operation to fuse into one the 

 great agricultural interests of the country. The 

 author concludes that "to-day the whole fabric of 

 reconstruction is in ruins," whereas it probably would 

 have been better if the Agricultural Act could have 

 been suspended rather than destroyed, for the Act 

 itself was based on sound principles and caij'ried a 

 promise, not for agriculture alone, but for the whole 

 country. 



In a paper in the October issue of the Quarterly 

 Journal of Forestry Mr. H. J. Denham directs atten- 

 tion to the fact that in calculating the times of fall 

 of seeds of forest trees it has been the custom to neg- 

 lect the resistance of the air. In the case of small 

 seeds this leads to results much less than the actual 

 time of fall, which is determined mainly by what is 

 known in physics as the " terminal " or " limiting " 

 velocity when the gravitational acceleration is exactly 

 counterbalanced by the air resistance. The seeds ex- 

 perimented on attained this velocity in the first three 

 metres of fall, and the time taken to fall the next 



NO. 2717, VOL. 108] 



four metres was observed. For certain species of ash 

 and sumach the limiting velocity was 1-5 metres per 

 second, for a maple 1-25 metres, while for a great many 

 species of pine and cedar it is only about 08 metre 

 per second. Seeds provided with a thin lamina fre- 

 quently spin in falling, and the centrifugal force 

 brought into play flattens the lamina and increases 

 the time of fall. The bearing of the limiting velocity 

 on the dispersal of seeds is obvious, and further 

 research is desirable in the interests of forestry. 



We have received vol. i, No. i, issued on October 

 17, of the Bulletin of the Hill Museum, a newly 

 instituted magazine devoted to Lepidoptera, and edited 

 by Messrs. Joicey and Talbot. Great credit is due 

 to Mr. Joicey for establishing this journal, and giving 

 the results of studies carried out in his private museum 

 at Witley to the entomological world. It is only a 

 wealthy man or a public body that is in a position 

 to amass collections on the scale carried out by Mr. 

 Joicey. No apology is needed for this practice, since 

 it is only by means of extensive collections that it 

 is possible to carry out research into many of the 

 problems concerning Lepidoptera. W^ork on variation 

 and geographical distribution, for example, is very 

 dependent upon access to large numbers of specimens. 

 The appearance of an addition to the already long 

 list of entomological periodicals may cause exclama- 

 tion in some quarters, but it must be pointed out 

 that most of the existing journals which usually 

 accept papers on Lepidoptera are greatly taxed for 

 space, and the high cost of publication has entailed 

 an inevitable reduction in their pages. The sample 

 issue before us is clearly printed and fully illus- 

 trated by twenty-four half-tone plates. Intending sub- 

 scribers to this magazine should communicate with 

 Mr. G. Talbot, curator, the Hill Museum, Witley, 

 Surrey. The editors will be glad to hear from any 

 societies or institutions desiring to exchange their pub- 

 lications. The subscription price is 30s. per annum 

 post free. 



Mr. Bailey Willis describes in Science (vol. 54, 

 1921) a new and interesting method of tracing the 

 course of a great earthquake-rift by photography from 

 an aeroplane. One of the most important rifts is 

 that of San Andreas, along which the Californian 

 earthquake of 1906 originated. It has been traced 

 tor a distance of about 600 miles, from Humboldt 

 County in northern California to the Mohave Desert 

 in the south of the same State. The fault is an 

 ancient one, and has been the scene of innumerable 

 movements which have given rise to pronounced topo- 

 graphic features. Mr. Willis's photographic survey 

 was carried out during flights from San Francisco 

 to Los Angeles and back, over a distance of about 

 400 miles. In the northern part, where rainfall is 

 abundant and erosion efficient, there is not much to 

 be seen after fifteen years. Farther south the rift 

 can be traced by the linear arrangement, sometirhes 

 for 25 miles, of numerous landsl'de scars and small 

 ponds. When it enters the desert country, in which 

 the aridity of the climate limits erosion, the signs 

 of the rift become more distinct and continuous. 



