86 + 



THE POPULAR SCIENCE MONTHLY. 



jected to a hydrographic examination by Mr. 

 A. T. Drummond. It is a deep-water lake, 

 giving soundings of six hundred feet, and is 

 found by Mr. Drumrnond to be also a cold- 

 water lake, giving bottom temperatures in 

 August of 44 - 75° Fahr., with the high sur- 

 face temperature maintained for relatively 

 only a few feet ; beneath this depth the mer- 

 cury falls rapidly toward the lowest reading. 



A writer in the Lancet calls attention to 

 our still persisting lack of practical knowl- 

 edge on the hygiene of schools, although a 

 complete revolution has taken place during 

 the past fifty years in our ideas relating to the 

 management of children and the methods to 

 be adopted in educating the young. This 

 position of affairs seems to have arisen, not 

 from any want of knowledge in sanitary af- 

 fairs, but rather from lack of system in fol- 

 lowing up the subject. We habitually in- 

 sist that certain conditions shall be fulfilled 

 before a dwelling house shall be considered 

 habitable or a hospital fit for the reception 

 of patients, and in other matters, but do not 

 as firmly stipulate that certain rules shall be 

 followed in the building of schoolhouses. 



A number of the plates — so many of them 

 being missing as to preclude the formation of 

 couplete sets — of Audubon's Birds of Amer- 

 ica, are offered for sale by Estes and Lauriat, 

 Boston, at largely reduced prices. Of many 

 of the plates but few copies are in store, and, 

 the original stones having been destroyed, it 

 is certain that no more copies will be pub- 

 lished. 



Volume V, No. 2, of Insect Life is chiefly 

 filled with proceedings of the sixth meeting 

 of the Association of Economic Entomolo- 

 gists, which was held in connection with the 

 meeting of the American Association at 

 Rochester in August, 1892. 



Metallurgy is tending to become one of 

 the most efficient producers of manures in 

 the world. Twenty years ago, says the Annates 

 indvstr idles, twenty thousands tons of phos- 

 phoiic acid were as poison to the two million 

 tons of cast iron which England produced, 

 while English ships were ransacking the 

 most distant regions of the globe for phos- 

 phoric acid for agriculture. The basic pro- 

 cess has been the end of this anomaly. Ap- 

 paratus attached to the furnaces in Scotland 

 for the recovery of the ammonia out of the 

 furnace gases have furnished a new and im- 

 portant source of sulphate of ammonia for 

 agriculture. 



A curious method of anthropometiical 

 measurement for the determination of iden- 

 tity is described by the French Captain Cu- 

 pet as in use in southern Anam. A sliver 

 of bamboo is placed between the middle and 

 fore fingers of the left hand of the person it is 

 desired to identify, and on it notches are cut 

 to mark the base of the nail and the distance 

 between the phalanges. The stick is kept, 



to be used as occasion requires when the 

 identity of the person in question is to be 

 established. 



The emerald mines of Muzo, Colombia, 

 are situated on the Minero River, about 

 eighty miles northwest of Bogota, and are 

 farmed out to a French syndicate. They are 

 situated in a very rough, wild country, with 

 nearly impassable roads, and are worked by 

 open cuts, with provision for washing away 

 the debris. The rough stones are for the 

 most part sent to Paris to be cut. About 

 three hundred natives are employed at the 

 works, and the yield is about one hundred 

 thousand dollars a year. 



The advance in the knowledge of the 

 coal fields of India, promoted by the Geo- 

 logical Survey of the country, is great. The 

 centers of production, which a few years 

 ago were almost confined to Bengal, have 

 been extended to Assam, the Punjaub, the 

 central provinces, the Nizam's territory, and 

 Burmah. The survey has also done much to 

 determine the character of the oil resources 

 of the country. The Government is anxious 

 to associate natives educated in the country 

 with the European officers in the work of 

 original investigation and research ; but the 

 attempt has had to be abandoned for the 

 present in consequence of the difficulty of 

 finding young men suitably educated for such 

 a career. 



OBITUARY NOTES. 



The Rev. Charles Pritchard, D. D., Savil- 

 ian Professor of Astronomy in the Universi- 

 ty of Oxford, whose death was recently an- 

 nounced, was in his earlier life a teacher in 

 the English upper middle-class schools, in 

 which he distinguished himself by his efforts 

 to exhibit an improved method of education. 

 After thirty years of this occupation, he re- 

 tired to become an active clergyman, but in 

 1870 was offered and accepted the professor- 

 ship at Oxford. Here he secured the estab- 

 lishment of the university observatory ; ap- 

 plied photography, before the gelatin plate 

 came into use, to the moon and other bright 

 objects ; devised and used a method of in- 

 vestigating the magnitude of the brighter 

 stars through a process of extinction by 

 means of a wedge of neutralized glass ; visit- 

 ed Egypt to determine the amount of atmos- 

 pheric absorption; studied the mutual proper 

 motions of the stars of the Pleiades ; and 

 began the investigation of the parallax of 

 stars of the second magnitude. 



The death, on August 16th, is announced 

 of M. Jean Martin Charcot, of the Salpetriere, 

 Paris, the eminent specialist in diseases of 

 the nervous system. He was most distin- 

 guished for his researches in the field of in- 

 sanity, hysteria, hypnotism, and of all those 

 nervous phenomena which have been asso- 

 ciated by many with magnetic influences. 



