432 



THE POPULAR SCIENCE MONTHLY. 



croscopic forms of both vegetable and ani- 

 mal life. 



The experiment of irrigating the lands 

 at Genevilliers with water from the sewers 

 of Paris appears to be working successfully. 

 In answer to protests which have been made 

 against applying a similar irrigation to the 

 forests of St. Germain, the engineers say 

 that the apprehensions that have been ex- 

 pressed on the subject are exaggerated. 

 Many buildings have been put up at Gene- 

 villiers since the sewer-waters were taken 

 there, but the inhabitants have never been 

 sick. Moreover, since the prevailing winds 

 are from the west, places lying east of the 

 irrigated district should be the ones most 

 troubled with the infection if there were any ; 

 but no complaint has come from Clichy, 

 which is thus situated, while the barren 

 tracts on which it looked have been convert- 

 ed into a fertile plain. 



The French journals tell of some per- 

 fectly fresh meat that became phosphores- 

 cent. Some cutlets of raw pork shone so 

 brightly in the kitchen that it was possible 

 by the aid of the light to tell the time by 

 the watch. The butcher from whose shop 

 they came said that all the meat of which 

 they were a part of the stock became phos- 

 phorescent within a short time after having 

 been put into his cellar. The phosphores- 

 cent meat did not otherwise differ in aspect 

 or odor from common meat ; it had not been 

 exposed to a temperature of more than 50, 

 and entire freshness seemed to be a con- 

 dition of phosphorescence, so that when the 

 meat began to smell it ceased to be bright. 

 The phosphorescence generally disappeared 

 on the sixth or seventh day. 



M. L. Cruls has communicated to the 

 French Academy of Sciences notes of ob- 

 servations which he has made at the Impe- 

 rial Observatory, Rio Janeiro, on stars un- 

 favorably situated for observation from the 

 Northern Hemisphere. Some of these stars 

 appear to possess a slow but well-defined 

 orbital motion, amounting in some instances 

 to about six degrees retrograde in forty- 

 three years. They have been observed here- 

 tofore only by Sir John Herschel at the Cape 

 of Good Hope, and by Captain Jacob at 

 Poonah, India, and it is from a comparison 

 with their observations that he has deduced 

 the fact of motion. 



The Royal Society has this year awarded 

 the Copley Medal to Professor' J. J. Sylves- 

 ter, at present occupying the chair of Math- 

 ematics in Johns Hopkins University. 



M. DE Lesseps has a plan for the civiliza- 

 tion of Africa by telegraph. Stations for 

 entertainment and for scientific purposes are 

 to be established at points between the coasts 

 and the interior. Thus a party has already 



arrived in the Oussagura to establish a sta- 

 tion to be connected with Zanzibar, and an- 

 other party has been commissioned to es- 

 tablish a station on the Ogove River to be 

 connected with the French colony at the 

 Gaboon. The stations are to be connected 

 by telegraphic wires, the planting of which 

 will be preliminary to the building of rail- 

 ways, so that these wires, says M. de Lesseps, 

 will become for Africa, as they were across 

 our Western Plains and are for Australia 

 and for the Russians in Central Asia, real 

 conductors of civilization. 



Professor Henry Draper writes in the 

 November number of the " American Jour- 

 nal of Science " that, " during the night of 

 September 30, 1880, I succeeded in photo- 

 graphing the bright part of the nebula in 

 Orion in the vicinity of the trapezium. The 

 photographs show the mottled appearance 

 of this region distinctly. They were taken 

 by the aid of a triple objective of eleven 

 inches aperture, made by Alvan Clark & 

 Sons, and corrected especially for the pho- 

 tographic rays. The equatorial stand and 

 driving clock I constructed myself. The ex- 

 posure was for fifty minutes. I intend at an 

 early date to publish a detailed description 

 of the negatives." 



M. Abel Pifre has succeeded, by chang- 

 ing the form of the reflectors and the heat- 

 ers, in considerably increasing the efficiency 

 of the solar engines invented by M. Mouchot. 

 While M. Mouchot has not been able to util- 

 ize more than fifty per cent, of the heat of 

 the sun, M. Pifre with his improved appa- 

 ratus makes eighty per cent, available for 

 use. With a receiver of 9-25 square metres 

 and a clear sky he boils fifty litres of water 

 in less than forty minutes, and obtains an 

 additional pressure of one atmosphere every 

 seven or eight minutes. 



It is proposed to make use of the hy- 

 draulic constructions and machinery at Ai- 

 rolo and Goeschenen for the maintenance of 

 electric lights in the St. Gothard Tunnel. 



A ROCK-DRILL run by electricity has been 

 devised by Messrs. Siemens and Halske of 

 England. It consists of a rod of steel-head- 

 ed soft iron which moves through three coils 

 of insulated wire ; the middle coil is trav- 

 ersed by a constant current which magne- 

 tizes the rod, and the other coils are trav- 

 ersed by alternating currents which attract 

 and repel the rod with rapid movements. 



"NATrEE" chronicles the death of Dr. 

 Hofrath von Wagner, Professor of Tech- 

 nological Chemistry in the University of 

 Wiirzburg. He was born at Leipsic in 1823, 

 first taught in Niiremberg, and was the au- 

 thor of a standard work on chemical tech- 

 nology, translated into English by Professor 

 Crookes in 1872. 



