396 Correspondence of J. Nickles. 
ary engines, of a series of parallel straight tubes, surrounded by co 
water on their outside to determine the liquefaction of the vapor; and 
the heat <ahan up to the cnnideneliig water is also availed ie im part in 
feeding the boiler 
In Piensa led the condensation acts in a still more dials manner. 
Four openings are provided in the hull of the ship on each side of the 
keel, two forward and two aft, covered and connected respectively by 
large copper tubes, open at te ends to allow the free circulation of wa- 
ter, when the vessel is in motion. These openings are controlled by large 
stopcocks. If within these large tubes, one or more condensing tubes 
are extended, on liquefaction of the steam is effected freely, and without 
the need of any mechanism, or the consumption of any power. 
system of Alxie Sauvage, for feeding steam boilers with condensed va- 
bos claims the following advantages : 
Ist, An increase of power in all engines, and especially in ee pres- 
sure ei 
2d, eines simplification of the condensing engine 
3d, Diminished consumption of fuel, due, (1) to the use of water at 
35° to 40° C. (= 95° to 104° F)5 (2) to the absence of solid or muddy 
incrustations in the boiler; (3) to the absence of foam or spray in the 
steam from pure des giving dry steam, or steam free from water me 
4th, The preservation of the boiler from the injuries resulting from the 
mechanical operation of removing the deposits, and above all, from all 
dan. ruising the iron. 
[It is but just to an ingenious American inventor, Mr. Stephen A. 
Gold, to say that he many linia since constructed a steamboat for ocean 
navigation, in which the condensation of the steam was effe in & 
hollow metal keel, with perfect suce ease ie 
Telegraph_—The Academy of Sciences has recently had un- 
der discussion the question whether the passage of an electric wire _—- a 
of powder, would be a source of danger. It was referred to 
upports. 
it is dierent with atmospheric electricity, which may be of great power, 
and serious in its consequences, if a pow wder magazine were near by. A 
stroke of lightning _— fase the wire for some length, and throw the 
melted g a considerable distance, and farther still, with the aid 
ides, the inflamed ends of the wire could no t fail to 
ds of a = poder 
ra enough from the sree i 
