2^2 



NATURE 



[July 9, 1903 



The Journal de Physique contains two short papers by 

 M. R. Blondlot on a new kind of light obtained originally 

 after filtering the rays from a focus tube through aluminium 

 or black paper. In studying the action of the radiations on 

 an electric spark, they were shown to present the phenomena 

 of rectilinear polarisation, and it was further found that 

 both quartz and sugar produced rotatory effects. On pass- 

 ing the rays through a plate of mica, double refraction took 

 place ; finally, the existence of refraction was proved by 

 concentrating the rays with a lens, and reflection was also 

 observed. It followed that the radiations were entirely 

 different from Rontgen rays, and must be attributable to a 

 new kind of light. In the second paper in the July number, 

 M. Blondlot finds that radiations possessing identical 

 properties are obtained from an Auer lamp, and that the 

 new rays will pass through certain metals and substances 

 which are opaque to the radiations discovered by Prof. 

 Rubens. 



In the Proceedings of the Royal Society for March, Mr. 

 H. M. Macdonald, F.R.S., gave an investigation of the 

 bending of electric waves round a spherical obstacle, which 

 was suitable to explain Mr. Marconi's successes in employ- 

 ing wireless telegraphy over distances representing con- 

 siderable arcs of the earth's circumference. Mr. Mac- 

 donald 's solution has been called in question in papers com- 

 municated to the Royal Society by Lord Rayleigh and M. 

 Poincar^. It is pointed out that Mr. Macdonald's con- 

 clusion as to the diffraction taking place without the pro- 

 duction of any sensible shadow does not agree with the 

 results known in the case of light ; indeed, if the conclusion 

 were accepted without any limitations, there would neces- 

 sarily be daylight all night. From a mathematical point 

 of view the results depend on the assumption that the 

 spherical functions entering into the expression for the 

 potential satisfy a condition of the form dW/dr^ifcW ; 

 this is true in the case of spherical functions of low order, 

 but unless the series for the potential is uniformly con- 

 vergent, the solution may involve spherical functions of 

 high order, for which the condition in question does not 

 hold good. 



We have received from Prof. B. Sresnevsky a pamphlet 

 containing synoptic tables of the daily rainfall values at all 

 the meteorological stations of the Russian Baltic provinces 

 for the year 1900. 



The Transactions of the South African Philosophical 

 Society for April last contains a lengthy contribution by 

 Mr. J. R. Sutton, superintendent of the De Beers 

 meteorological station at Kenilworth, Kimberley, on the 

 results of some experiments upon the rate of evaporation. 

 For, as the author points out, of the dozens of patterns 

 of evaporators, not one has hitherto been unreservedly 

 accepted as a standard, and the results obtained 

 fforti some of them show a rate of evaporation fully 

 twice as great as others. The greatest mean annual result 

 of seven years' observations by the author gives an evapor- 

 ation of 90- 1 1 inches, and was obtained from a copper pan 

 about 5 inches deep and 8 inches in diameter, kept nearly 

 full of water, and protected from the sun's rays. The 

 monthly means varied from about 3 inches in June to nearly 

 12 inches in each of the months November and December. 

 For the year 1900, the comparative annual values given by 

 four evaporators are :— 8-inch copper pan, 90-82 inches ; a 

 screened iron tub, enamelled white inside and out, 14 inches 

 in diameter and 20 inches high, 61-98 inches; circular steel 

 tank, nearly 4 feet in diameter and 30 inches deep, 55-21 

 inches ; a Piche evaporating tube of the usual pattern, 82-83 

 NO. 1758, VOL. 68] 



inches. The author finds (i) that the most potent agency 

 regulating the rate of evaporation was the humidity of the 

 air; (2) that a wind factor is suggested; and (3) that the 

 great perturbing influence attributed to the temperature of 

 the water has not been exactly confirmed. The paper will 

 well repay a careful study. 



Evidence of a connection between the occurrence of 

 thunderstorms and the moon's age has been referred to in 

 Nature on several occasions. Prof. W. H. Pickering gives 

 a table in Popular Astronomy to show the results of investi- 

 gations of this relationship by various observers. From 

 this table, which is abridged below, it will be seen 

 that, with one exception, the number of thunderstorms 

 occurring near the first two phases of the moon is greater 

 than the number occurring near the last two. 



The Moon's Phases and Thunderstorms. 



Prof. Pickering adds :— " The number of observations here 

 collected seems to be large enough to enable us to draw 

 definite conclusions, without fear that further records will 

 revise or neutralise them. From these observations we 

 conclude that there really is a greater number of thunder- 

 storms during the first half of the lunar month than during 

 the last half, also that the liability to storms is greatest 

 between new moon and the first quarter, and least between 

 full moon and last quarter. Also we may add that while 

 theoretically very interesting, the difference is not large 

 enough to be of any practical consequence. Thus it would 

 seem that, besides the tides and certain magnetic disturb- 

 ances, there is a third influence that we must in future 

 attribute to the moon." 



Fresh evidence is continually coming to light to prove 

 the artistic skill of the cave men of late Palaeolithic times. 

 M. E. Cartailhac has begun a memoir in V Anthropologic 

 (tome xiv. No. 2) on the stations at Bruniquel, on the banks 

 of the Aveyron, which will add materially to our knowledge 

 of these interesting people. Especially remarkable is an 

 engraving, published by the same author (p., 179), of two 

 bands of horses in alignment on a slab of stone from the 

 main cave at Chaffaud, Vienne. This is the first example 

 of regular grouping, and an indication of perspective in 

 Pala;olithic pictorial art. 



The shell-heaps of the Lower Eraser River, British 

 Columbia, have been carefully investigated by Mr. Harlan 

 I. Smith in connection with the Jesup North Pacific 

 Expedition, and his results are now published, with 

 numerous illustrations, in the Memoirs of the American 

 Museum of Natural History, vol. iv. These shell-heaps 

 seem to have certain peculiarities of their own ; the objects 

 found in them are more numerous and of higher artistic 



