1 693' 



NOTES AND COMMENTS. 655 



however, has at last been made, and Messrs. J. S. Diller and 

 A. Hyatt {Bull. Geol. Soc. Amcvica, 1892, pp. 369-412) announce the 

 occurrence of the formation near the summit of the Sierra Nevada, 

 in Plumas Co., California. ^ 



In a paper on the Trias of Cannock Chase (read before the 

 Liverpool Geological Society, 1892), Mr. T. Mellard Reade refers to 

 certain "indented pebbles" the depressions in which have usually 

 been attributed to the effects of pressure. He is of opinion that the 

 surfaces of siliceous pebbles at the point of contact in the Triassic 

 rock have been eroded by the solvent power of water. 



In reference to M. Carnot's observations on fluoride of lime in 

 fossil bones noticed last month (p. 565), Mr. T. L. Phipson contributes 

 to the Comptes Rendus (vol. cxv., p. 474) an observation of some 

 interest. He remarks that many years ago he analysed a piece of 

 fossil wood from Cretaceous sandstone (evidently Wealden) in the 

 Isle of Wight, and found so large a percentage of phosphoric and 

 fluoric acids, that mineralisation appeared to be almost entirely 

 effected by phosphate of lime with a small admixture of the fluoride. 



The most detailed account of the Dover Boring hitherto pub- 

 lished in any journal has just appeared in the Anitales des Mines (1892, 

 pp. 227-232). The particulars are given on the authority of Mr. 

 Brady, the Engineer, and they are communicated by M. E. Lorieux. 



In the October number of the Scottish Geogvaphical Magazine the 

 Prince of Monaco publishes a new chart of the currents of the North 

 Atlantic, presented to the British Association at the Edinburgh 

 meeting this year. Nearly 1,000 floats were used by the Prince in 

 the course of his researches, and of these 227 were returned with 

 particulars of their discovery on various coast-lines. A curious great 

 vortex is recognised in the ocean to the west of the Azores. " Just 

 as in an atmospheric cyclone, there exists in this oceanic vortex a 

 region of calm, where the waters do not follow any regular direction, 

 and when the floats enter this region they remain there often for 

 months or years." 



The Times publishes news of Mr. W. M. Conway's Expedition to 

 Mount Godwin Austen and its vicinity in the Hindu Kush, already 

 referred to in Natural Science (March, p. 6). The exploration of 

 the glaciers is being prosecuted with success, and Mr. Conway has 

 reached an elevation of 25,000 feet. 



Another expedition has just left England for Eastern Africa 

 under Lieutenants C. H. ViUiers and Bennett Stanford of the Horse 



