March 8, 1906] 



NA TURE 



447 



ten pounds per acre, and it is estimated that the farmer 

 would receive from seventeen to twenty shillings per ton of 

 trimmed roots delivered at the factory. 



In a paper read before the Royal Geographical Society 

 on January 29 Prof. G. F. Scott Elliot gave an account 

 of his observations on the various plants that aid in the 

 formation of alluvial flats in the valleys of such rivers as 

 the Aconcagua, in Chile, and the La Plata. The compo- 

 site shrub, Baccharis marginalis, protected from drought 

 by gum-containing leaves, was found to be one of the first 

 settlers to fix the banks on the Aconcagua, after which 

 other plants, including poplars and willows, could secure 

 a hold, and gradually a river-side wood might be formed ; 

 or in the deeper backwaters plants of the nature of 

 Scirpus americanus or ] uncus dombeyanus, and in the 

 shallows species of Eleocharis, spread out their horizontally- 

 creeping stems and upright stalks holding the mud and 

 catching the drift until, in the marshy condition, grasses 

 could grow over and fill up the swamp. 



An experimental station for the study of sugar-cane 

 cultivation and of the diseases of the sugar-cane was 

 opened at Samalkot by the Madras Government In 1902. 

 Mr. C. A. Barber presents a report of the work for the 

 year 1903-4 in Bulletin No. 51 of the Department of Land 

 Records and Agriculture, Madras. Two local varieties, 

 Bonta and Yerra, and an introduced cane, Red Mauritius, 

 were selected for special experiment ; the Bonta was eaten 

 out by jackals, the Yerra did not suffer much and gave 

 good results, but the Red Mauritius produced the greatest 

 weight of cane and the largest amount of jaggery. The 

 practice of wrapping the canes that is usual in the 

 Godavari district will form the subject of experiment ; the 

 older leaves are twisted and wrapped round bamboos fixed 

 in the ground ; the object is two-fold, the leaves serving as 

 a protection against jackals, and the bamboo supports 

 preventing the canes being blown down in cyclonic storms. 



A tornado of considerable violence occurred at Meridian, 

 in the State of Mississippi, on the evening of March 2, 

 involving much loss of life and causing great destruction of 

 property. The tornado is said to have travelled at the rate 

 of seventy-seven miles an hour, and to have passed away 

 in two minutes. It apparently travelled from south-west 

 to north-east, and in its progress it is reported to have 

 ploughed a path 600 feet wide and one mile long. 



A severe hurricane occurred in the South Pacific on 

 February 7 and 8, and was attended by very serious loss 

 of life and property. According to the report received in 

 this country from San Francisco, received there through 

 the steamship Mariposa, damage to the value of 20o,oooZ. 

 was wrought in Tahiti, and it is believed that similar 

 damage was caused in the Tuamotu Islands. The loss of 

 life is rumoured as numbering several thousands. Papiete, 

 situate on the north side of Tahiti, is said to have been 

 inundated, and it would appear that the hurricane was 

 accompanied by a series of high waves. The storm is re- 

 ported to have struck the islands with a wind velocity of 

 120 miles an hour at midnight on February 7, and to have 

 continued until four o'clock on the following afternoon. 

 In this part of the world storms usually travel from the 

 north-westward. According to the Admiralty sailing direc- 

 tions for the Pacific Islands, the hot months, December to 

 March, are those in which storms may be expected, and 

 clearly they are of fairly common occurrence in the Society- 

 Islands and in the Tuamotu Archipelago, but as a rule the 

 hurricanes do not appear to be so severe as those of the 

 Atlantic and Indian Oceans or of the China Seas. At 

 NO. 1897, VOL. 73] 



present the information to hand with respect to the recent 

 storm is very meagre, and further details will be anxiously 

 looked for. 



Japan has gained her supremacy in the East by a careful 

 and minute study of the methods of the West. It is now 

 the turn of the West to look towards the East for enlighten- 

 ment, and we do not look in vain. Weather is an 

 important item in commercial prosperity, and the study 

 of it is therefore of the highest importance to every nation. 

 If a country is subject to devastating cyclones, it is of the 

 utmost necessity that inquiry should be set on foot to try 

 to solve the causes of their frequency, and forecast, if 

 possible, their advent, in order to mitigate so far as 

 possible the damaging results which will eventually ensue. 

 One old British possession, a valuable asset to the British 

 Empire, is occasionally visited by these destructive air 

 movements, and instead of concentrating a meteorological 

 att.uk by erecting a first-class station, the British Govern- 

 ment reduces the already microscopic annual grant of 100/. 

 to 50/. In Japan science is respected, and respected prob- 

 ablv because that country knows that scientific method is at 

 the base of progress. In meteorological matters Japan 

 does not mean to be left behind, and as the first duly of 

 a German colonist seems to be to set up a barometer and 

 thermometer and read them, so Japan follows suit by 

 organising a meteorological service in Korea and Man- 

 churia. An article upon this service, and the first-class 

 observatory at Chemulpo, appeared in the U.S. Monthly 

 Weather Review for September, 1905, and has already been 

 noticed in these columns (February 15, p. 374). 



A conspicuous and valuable feature of recent numbers of 

 the Proceedings of the Tokyo Physico-mathematical Society 

 is the number of short papers containing simple applications 

 of deductive reasoning to physical phenomena. Thus we 

 have an extension of Gibbs's phase rule to systems in which 

 the potential differences between the phases enter into the 

 equations, by Shizuwo Sano (ii., 25); a theory of the rain- 

 bow due to a circular source of light, by K. Aichi and 

 T. Tanakadate (ii., 27); a discussion of the whistle pro- 

 duced by the vibration of a liquid drop, by T. Terada 

 (ii., 26); and an explanation of the existence of secondary 

 vibrations in seismic waves, by H. Nagaoka (ii., 28). 

 based on the supposition that the acceleration due to the 

 elastic force of the rock contains terms proportional to 

 powers of the displacement higher than the first. 



" A Problem in Analytic Geometry with a Moral " is 

 the somewhat attractive title of a paper by Prof. Maxime 

 Bocher in the Annals of Mathematics, vii., 1. The 

 problem, which is quite elementary, consists in the deter- 

 mination of all the families of conies which cut a given 

 conic, sav .\- 2 -y 2 = i, at right angles. Taking the inter- 

 secting conic as given by the general equation of the 

 second degree, the method of solution is to find the locus 

 of the points the polars of which with respect to the two 

 conies are at right angles, and to make this locus pass 

 through the intersection of the two conies. At this stage 

 the author advises the reader to complete the solution 

 himself before reading further ; if he does so, there is con- 

 siderable probability that he will fail to obtain all the 

 four solutions. The reason of this is that there is one 

 family of orthogonal conies such that the polars of any 

 point with respect to one of these conies and the original 

 conic are at right angles, so that the coefficients in the 

 equation of this locus vanish identically. The interesting 

 point is that these conditions determine, not a single 

 curve, but a family of curves with the same degree of 

 generality as the families determined by the other con- 

 ditions. 



