52 



NATURE 



[November 9, 191 1 



whether it can be shown that deforestation has augmented j 

 droughts and floods, an article is published in Ihc Indian \ 

 Forester (September) citing data and observations to prove 

 that forests do exercise a marked influence on the regula- 

 tion and maintenance of water supplies. The evidence sub- j 

 mitted falls under three heads. First, deforestation produces 

 a diminution or cessation of flow in the streams ; most of 

 the examples quoted belong to this category. Testimony 

 from Monroe, Wisconsin, affirms that in seventy years the 

 forest region has been reduced from 83 to 6 per cent. ; 

 coincidently, streams have dried up entirely, and mills 

 have ceased to operate. Secondly, reafforestation leads to 

 an increased water supply. An instance from Burma is 

 noted, according to which renewal of the forests on Popa 

 Hill, Myingyan, has averted the periodic drying up of the 

 streams. Thirdly, corroborative conclusions are derived 

 from a comparison of the flow in neighbouring streams, 

 fed in one case from protected, in the other from denuded, 

 catchment areas. 



The Board of Agriculture issues leaflets calculated to 

 serve a very useful purpose by giving information to 

 farmers on such problems as plant diseases, crop manage- 

 ment, and manures. The leaflets are short, concisely 

 worded, and where possible illustrated. Some of the recent 

 issues deal with bacteriosis of the potato and tomato ; 

 actinomycosis in cattle, a disease caused by the growth on 

 the animal's tongue of the parasitic fungus Actinomyces 

 coming from grasses, cereals, or the soil. Another leaflet 

 deals with the three weed grasses Triticium repens, 

 Agrostis vulgaris, and Arrhenatherutn avenaceum, all de- 

 scribed by the farmer as couch or twitch ; whilst a third 

 gives an account of the composition of seaweed and its 

 use as manure. 



The eleventh annual report of the Midland Agricultural 

 and Dairy College shows that the members of the staff 

 are responding in a splendid manner to the demands made 

 on them by students and farmers. The principal says of 

 one of the departments : " Every use has been made of the 

 time and facilities that are available, and often leisure 

 that ought to have been spent in recreation has been 

 devoted to extra work," a statement fully borne out by 

 the separate reports from the individual members of the 

 staff. The Board of Agriculture has increased the grant 

 to the maximum of loooi., but more space seems to be 

 needed in several departments. Favourable reports were 

 sent by the examiners, except only in one instance, and 

 there a perusal of the examination questions shows that the 

 fault lies with neither students nor staff. 



The summary of the weather for the week ending 

 November 4, issued by the Meteorological Office, shows 

 that the conditions were very stormy throughout the period. 

 Several large and important storm areas arrived from the 

 Atlantic and extended over the British Islands and their 

 neighbourhood. Severe gales were experienced on several 

 days during the week, and on Saturday, November 4, the 

 barometer at Thorshavn fell below 28-0 inches as the 

 central area of the storm traversed Fasroe. The rainfall 

 for the week e.xceeded the average in all districts except 

 in the north-east of England and in the English Channel. 

 In the west of Scotland the measurement was 3-89 inches, 

 which is 2-59 inches more than the average, and in the 

 north of Scotland the excess was 2-29 inches. The aggre- 

 gate rainfall for the nine weeks of the present autumn is 

 now in excess of the average in the south-east and north- 

 west of England, in the English Channel, and in the south 

 of Ireland, whilst the deficiency in other districts is being 

 NO. 2193, VOL. 88] 



greatly lessened by the recent heavy rains. At Greenwich 

 the rainfall for October was 3-29 inches, which is 0-44 inch 

 more than the average of the past sixty years ; and 

 October was the wettest month since November of last 

 year. 



Among several useful papers in the Journal of the 

 Meteorological Society of Japan for August is one, by Mr. 

 Y. Tsuiji, on earth temperature at Taihoku (Formosa 

 based on eleven years' observations (1897-1907). The 

 surface layer of the ground is clay, and underground water 

 is met with at a depth of about 20 feet. The tables show 

 that the average annual air temperature is 21-54° ^-t *"'' 

 at the surface of the ground 23-55' ; at 05 metre the mean 

 is 23-39°, 3t I metre 23-31°, at 3 metres 23-11°. The 

 mean decreases with depth, while the rate of diminution 

 also becomes smaller as the depth increases ; the annual 

 range diminishes with increase of depth, while the epoch 

 of extreme temperature is retarded. The author submits 

 the results to harmonic analysis, and remarks that they 

 show that if we are satisfied with a rough determination 

 of the mean values for practical use, there is no need for 

 that laborious process adopted in modern meteorology. 



In The Cairo Scientific Journal for September detail 

 are given of a slight earthquake shock which was felt in 

 Cairo on August 22 at loh. 23m. east European time. It 

 was characterised by the very rapid character of th 

 vibrations. 



In Petermann's Mitteilungen for October the results of 

 the census of Mexico taken in October, 1910, are dis- 

 cussed and presented in a map which shows the distribu- 

 tion of population density. The northern portion to the 

 north of lat. 25° is scantily peopled, having a population 

 of from one to three to the square kilometre. The most 

 densely peopled region is in the central part by Mexico, 

 where a small portion is shown as having 480 inhabitant 

 per square kilometre. 



We have received a catalogue of surveying and drawing 

 instruments made by Messrs. C. F. Casella and Co., Ltd., 

 of II Rochester Row, London, S.W. Besides the usual 

 types of instruments, this firm constructs several of a 

 special character, and full descriptions of some of these 

 are given in the catalogue. Among these we may not 

 Reeves's tangent micrometer for use on sextants arni 

 theodolites; Reeves's distance-finder alidade, in which the 

 3-foot alidade rod can be utilised as a distance finder, so 

 that when used on a plane table the distance of objects 

 can be determined either by intersection or by direct 

 measurement. Hep worth's electric artificial horizon is a 

 simple attachment by which, when a line on the horizon 

 glass is in alignment with the eye of the observer and the 

 natural horizon, the observer is notified by an audible 

 signal, so that the use of the sea-horizon is no longer 

 necessary, and observations can be taken when fog or mist 

 may obscure the horizon. 



The Journal of the Franklin Institute for October con- 

 tains an abstract of a paper on the rSle of water in 

 minerals, by Dr. \\'. W. Coblentz, of the Bureau of. 

 Standards, Washington, which gives an account of a 

 method of investigating the question which seems likely to 

 furnish more definite information than has been available 

 in the past. Dr. Coblentz examines the infra-red absorption 

 spectra of a number of minerals having water of crystal-, 

 lisation by means of a vacuum bolometer and a mirror;; 

 spectrometer. He finds that in some cases the absorption 

 spectrum of the crystal is not, while in other cases it is. 



