72 ANNUAL OF SCIENTIFIC DISCOVERY. 



the crank, with its connecting-rod, etc., is enclosed in a steam- 

 tight head, so arranged as to form an extension from one end of 

 the cylinder in which the piston works, and to this piston the con- 

 necting rod is directly 43ivoted, the opposite end actuating the Hy- 

 wheel. To close the communication between the cylinder and 

 tlie hollow head, a transverse slide is fitted with a rocking-block 

 through which the connecting-rod passes, the combined action of 

 which provides for the free motion of the connecting-rod, and, at 

 the same time, forms a sufficiently steam-tight division between 

 the cylinder and head. — American Oas-Light Journal. 



HUGON GAS ENGINE. 



In this engine, as now perfected, by a simple arrangement, the 

 gas, as soon as it is turned on, enters the cylinder mixed with 

 about 9 times its bulk of common air. All that is necessary to 

 start the engine is to light 2 ordinary jets of gas, which in their 

 turn light 2 others ; these last inflame the explosive mixture of 

 gas and air conveyed to the cylinder, and, being extinguished by 

 the explosion, are relit by the 2 jets fixed outside the cylinder. 

 At the moment of explosion, a very fine spray of water falls on the 

 piston, and (the heat being then 1,200'^ F.) becomes steam, thus 

 reducing the heat and equalizing the pressure throughout the 

 stroke, so that the engine lubricates itself by its own action. 

 Among its advantages are : from perfect rest to full activity not 

 2 minutes elapse ; it is as easily set to work as a gas-jet is lit, 

 and is as instantly stopped, and is thus, at all times of day or 

 night, at the service of its owner. It is simple, economical, clean, 

 safe, and remarkably steady in its working ; it requires no skill to 

 start it, nor attention while in operation. 



TREATMENT OF ANIMAL REFUSE. 



In the second Annual Report of the New York "Metropolitan 

 Board of Health," is a paper upon the operations of the " New 

 York Rendering Companj^" by Drs. Morris and Janes, from 

 which the following are extracts : — 



. A dock at the foot of 38th Street, North River, was set apart 

 by city ordinance for the reception of butchers' ofl:al and all dead 

 animals found in the city limits ; boats, provided for the purpose, 

 were moored at this dock during the day, upon which the materials 

 were loaded until night, when they were taken down the bay to 

 Barren Island and discharged. In consequence of the daily ac- 

 cumulation and of the delay in removal, this dock had been for 

 years a most offensive nuisance; many kindred obnoxious kinds 

 of business had gradually been located in the neighborhood, for 

 several blocks around, whose offensive odors impregnated the air 

 for a great distance. The accumulations of butchers' offal, dead 

 animals, and market refuse, exhaletl the most obnoxious and air- 

 poisoning odors, lying upon the dock during the whole day, and 



