436 Miscellaneus Intelligence. 
deaux, has presented some Researches on the laws of the magnetism of 
rotation. It is impossible to give here details of these memoirs, which 
moreover will all appear in the official organ of the Academy of Sci- 
ences, the Comptes Rendus, published every Saturday. 
Manufacture of Powder.—In the No. of this Journal for Sept. 1853, p- 
270, I have spoken of an improvement in the manufacture of powder, ap- 
plied for the first time at the manufactory of Esquerdes which produces, 
owing to this improvement, the products highest in reputation in France 
or other countries. The improvement depends on a new method of pre- 
paring the charcoal, which is obtained by calcination of the wood by 
means of a current of overheated steam. This charcoal, called charbon 
roux, has but one objection, which is its price. 1e 
To overcome this difficulty, another member of the commission on 
powder and saltpetre, M. Gessart, has devised a method of executing 
this process, by heating with gas, which saves about 80 per cent. of 
proposed, 100 kilograms of wood may be carbonised at once. ‘The tol- 
lowing is the method.—The water for evaporation is injected through 
p whose piston is charged with a weight little above the force of 
tension desired for the vapor. The pressure causes the water to rise 
through a graduated orifice, in a series of tubes arranged like a ladder, 
and enclosed in tubes of larger bore. These last convey the gas, and 
also serve for the condensation of the steam after it leaves the carbon- 
ising apparatus. The circulation goes on from above downward. 
tine with parallel tubes arranged so as to cover the top and sides of the 
furnace. The water vaporises in these tubes and is overheated 1M 
its passage across the metal turnings or granulated metal with which 
they are filled. The steam thus overheated is conducted into a reset 
voir of cast iron furnished with a thermometer and a manometer indi- 
now nearly cold, pass out to be rejected by an arrangement for this 
purpose at the lower part of the apparatus. The air for promoting the 
combustion is heated by passing along a portion of the walls of the 
chimney and the vent-holes before arriving under the grating, by whic 
a heat is economised. The following are the advantages of the 
method. 
1. Only one fire is used for producing the overheated steam; and @ 
i fireman suffices. nae 
steam is heated, and just as it is soanile 
+ 
