864 



THE POPULAR SCIEXCE MONTHLY. 



Mn. Harris, of the Institute of Civil 

 Engineers, contradicts the belief, which is 

 general, that niine-cxplosions are always 

 accompanied by a low barometer. Very 

 few of the explosions of 1S86 and 1887 

 were thus accompanied ; and out of the list 

 of disasters in the eleven years ISYS-'oS, 

 given by Sir Frederick Abel, only IS'Vo 

 per cent of the accidents and 1'7'4 per cent 

 of the deaths occurred when the mercury 

 was at 29 i inches or below. One half of 

 this small percentage of explosions took 

 place with a low but rapidly rising barom- 

 eter, when gas had begun to issue from the 

 strata. 



Mr. Francis Galton has described his 

 ideal of an anthropometric laboratory as a 

 place wliere a person may have any of his 

 various faculties measured, and where dupli- 

 cates of his measurements may be preserved 

 as private documents. Besides the ordinary 

 simpler apparatus, such an institution should 

 contain instruments for psycho-physical re- 

 search, for determining the efficiency of each 

 of the various senses and certain mental 

 constants. Instruction might be afforded to 

 those who wish to make measurements at 

 home, together with information about in- 

 struments and the registration of results. A 

 library would contain works relating to the 

 respective influences of heredity and nur- 

 ture. It might also fulfill a welcome pur- 

 pose as a receptacle for biographies and 

 family records. 



Otto Wikner, having made certain meas- 

 ures of the thickness of a film of silver 

 which can just be perceived by the eye, con- 

 cludes that 0-0000002 of a millimetre is 

 an upper limit of the diameter of a silver 

 molecule. 



Mr. W. H. Preece said, in papers read in 

 the British Association on " Copper Wire," 

 with particular reference to its use in teleg- 

 raphy and telephony and high-speed teleg- 

 raphy, tliat the speed of transmission on 

 inland circuits had increased from eighty 

 words per minute in 1870, to six hundred 

 in 1887, and on the most difficult line to 

 Dublin, from fifty words in 1870 to four 

 hundred and sixty two in 1887. In fact, as 

 many words could now be transmitted on 

 one wire as on nine in 1870. Those im- 

 pvovements had been the results of greater 

 perfection in apparatus, the elimination of 

 electro-magnetic inertia, the improvement 

 of the circuits (the wire and its surround- 

 ings), and the introduction of high-speed 

 repeaters. 



OBITUARY NOTES. 



George W. Tryon, Jr., the distingui.shed 

 conchologist, died at his home in Philadel- 

 phia, February 5th. \\v. was conservator of 

 the conchological collections of tlie Acade- 



my of Natural Sciences of Philadelphia, 

 which is said to outrank even those of 

 the British Museum, and was himself the 

 owner of the most numerous collection in 

 the world. He spent the later years of his 

 life in arranging and systematizing the 

 Academy's collection. He prepared tlie 

 " Manual of Conchology, Structural and 

 Systematic," which, although it has reached 

 its fourteenth volume, is left unfinished. 

 He was the author of a work on the marine 

 conchology of the eastern United States and 

 of a general manual of recent and fossil 

 conchology, and was one of the founders 

 and editor of the " American Journal of 

 Conchology." His fame was world-wide, 

 and his standing among conchologists in the 

 highest rank. 



Dr. Joseph B. Holder, Curator of the 

 American Museum of Natural History, died 

 suddenly at his home in this city, February 

 2Sth. He had been connected with the 

 museum for several years, and had taken an 

 important part in the arrangement and clas- 

 sification of its collections. He was a fre- 

 quent writer on subjects connected with his 

 lines of work, being the author of many 

 articles in public journals, magazines, and 

 scientific periodicals, and of books. 



Emil Rousseau, a French chemist, died 

 in Paris, February 4th, in the seventy-fourth 

 year of his age. After working in the lab- 

 oratories of Orfila and Dumas, and in the 

 Central and Municipal Schools, he estab- 

 lished a manufactory of chemical products, 

 at which subsequently Sainte-Claire Deville 

 and Debray with his aid worked out the in- 

 dustrial fabrication of aluminum. He first 

 applied pyrites to the fabrication of sul- 

 phuric acid, introduced a new preparation 

 of charcoal, and devised the sugar process 

 known as the Rousseau process. 



The death is announced of Dr. J. T. L. 



Boswell, a well-known English botanist, 

 who was for many years Curator to the Bo- 

 tanical Society in London. 



Anton de Bary, the eminent botanist 

 of the University of Strasbiu'g, died Janu- 

 ary 19th after a painful illness. He was 

 born in 1831, was Professor of Botany suc- 

 cessively at Freiburg, Halle, and Strasburg, 

 was famous for his researches on the algaj 

 and fungi, was for many years after 1807 

 editor of the " Botanische Zeitung," and 

 was the author of numerous treatises chief- 

 ly relating to cryptogamic vegetation, physi- 

 ology, and morphology. 



Mr. Georoe RonERT Wateriiouse, late 

 keeper of the department of geology in 

 the British Museum, died on the 21st of 

 January, in the seventy-eighth year of his 



