594 



NA TURE 



[April 19, 1906 



ation of the arrangement by which the palaeontologists 

 were- enabled to accompany the party — a very proper plan, 

 and one which in this case greatly facilitated the speed 

 and exactness of correlation and mapping, besides 

 accumulating material for an import- 

 ani monograph on the fossils. 



The report contains two geological 

 maps and several views of the scenery. 

 An appendix on the reported ore de- 

 posits of the Wichita Mountains, by 

 Mr. II. Foster Bain, should be of use 

 as a warning to prospectors. 



(3) Henceforth let no man say there 

 is coal in Perry. For seventy years 

 have the dwellers in south-eastern 

 Maine cherished the hope that coal 

 lay within their borders ; ami had the) 

 not good reason '? Perry lies near tin- 

 edge of a structural basin, and the: 

 had been told that the " Perry " beds 

 were Triassic, conseauently that coal 

 might be found beneath them ; the 

 Canadian Geological Survey had 

 coloured the beds Carboniferous on 

 their map — in spite of Sir William 

 Dawson's diagnosis of the plants and 

 mining "experts," glancing at the 

 same obscure plant remains, had said, 

 " Here you an-, the very thing," and 

 had gladly bidden the people to bore; 

 and they bored, through the Pern 

 beds into the Silurian lavas, but into 

 no coal. Still in hope, the sum of 15,000 dollar- was 

 for to put down more bore-holes; it n;s decided, however, 

 first to call in the aid of the U.S. Geological Survey De- 

 partment, with the result that Messrs. Smith and White 

 were sent to examine the ground. Then, hey presto ' the 



preserved plants confirmed the age of the beds to be 



Devonian, probably Chemung, and, incidentally, produced 



two new generic tvpes. The plants are figured in six 



plates. ' J- A- H. 



rHH 



-"Jail Rock,"sho 



sked 



»» V 





g castellated form of weathering of G 

 clay ; valley of North Platte in the distano 



STUDIES OF TEMPERATURE AND 

 PRESS I 'R F. 1 iRSER V ATION S. 



obscurity vanished a ten days' reconnaissance was 

 enough. There is no coal in the Perry beds, only con- 

 glomerate with a little sandstone and shale and inter- 

 stratified basic lava. Subsequent examination of the badly 



no. 1903, VOL. 7j] 



]W|"ETEOROLOGISTS will be interested in a paper 

 recently published by Dr. van Rijckevorsel, and 

 entitled " {Constant auftretende secundare Maxima und 

 Minima in dem jahrlichen Verlauf der meteorologischen 

 Erscheinungen, " part ii. (Rotterdam: Van Hengel, 1905). 

 This is really the second portion of a previous publication, 

 only in this instance the number of stations dealt with 

 is more numerous, and the stations themselves more 

 generally distributed over the earth's surface. 



By the method explained in the pamphlet the author 

 has obtained for twenty-two stations the mean annual 

 1 jmperature variations, the resulting curve representing 

 the mean of observations of altogether 3636 years. The 

 author then proceeds to eliminate the annual period of 

 twelve months, and also discusses the residuals. The 

 main result at which he arrives is that, no matter whether 

 he deals with all the observations collectively, with the 

 European stations alone, or with stations collected in 

 north or south hemispheres, there is over the whole 

 earth's surface during twelve months a half-yearly period 

 of temperature the epochs of which are identical. It 

 shows maxima in the beginning of March and September, 

 and two minima in the first days of June and December. 

 Another oscillation which is referred to is one composed 

 of .1 series of very small maxima and minima. 



Willi regard, however, to the six-monthly oscillation of 

 temperature, a variation which seems to be clearly marked, 

 it is interesting to note that the epochs of maxima seem 

 lo pick out the times when the north and south poles of 

 I he sun are consent I ivelv turned towards the earth. 



As the author finds that stations representing the north 

 arid south hemispheres give practically identical results, it 

 would be interesting if he would try an east and west 

 system of grouping of stations, and see if the same result 

 is obtained. In the light of recent work, it seems quite 

 possible, but not probable, that if stations in North- 

 West Africa, South and North America, Honolulu, and 

 Siberia lie formed into one group, and the rest oi the world 

 into another, the same variation, but of opposite or nearly 

 opposite phase, might be the result. The attempt is well 

 worth trying, since the author his all the material at his 

 hand, and the more stations employed in South America to 

 counterbalance the larger number used and more easily 

 obtained in the European area the better. In this pamphlet 

 curves are given showing the variations derived, and 



