343
•
For the Journal of the Franklin Institute.
P~zrticulars of the Sleamer .Elan. Hull built by Laird & Co., Gree~aock. Intended service, Havre to New York. ]ttrLL.--
Length on deck, , t3readth of beam, (molded,) Depth of hohl, " " to spar deck~ Tonnage, I hull, engillO r O0 FII~
304 feet. 37 " 20 28
" "
2 2
" "
1222. I 2223. 100].,
M:asts--3.--Barquc rigged.-]~NGINgs.--Over-head beam. Diameter of cylinder, J,ength of stroke, Cut-off at Avcrage rcv01utiolls, Gcaring,.
8 inches,
76~ inches. 5 fcet.
~. 27, 2~ to t.
B 0ILE II.s.--Foll r--tubul ar.
Load on safety valve per square inch,
.-Number of furnaces, Consumption of coal per day,
14 lbs. 14. 45 tons.
PROPELLER.--
Diameter of screw, Pitch of screw,
14 feet
23
6 inches.
"
Remarks.--Frames, shape L 5~ ins.X~ in. and 15 ins. apart. Thickness of plates, .~ to 1 inch. Number of bulkheads, 5. Diameter of rivets, ¼. Distance apart, 3~ ; single riveted• Independent steam, fire, and bilge pumps, "2. C.H. H, For the Journal of the Franklin Institute.
Memoir :--On a new method of applyin~ the pozoer of steam, and of Con. densi~g lhe same after it has been so applied ; the former is designated The " D[ff~erential'' syslern o f Steam Power, and the latter, The Hot Water system of Condensation. By THomAs PaossEn, Cir. Eng., New York. There are two methods of applying steam as a motor, the positive and the negative; to which I purpose to add a third, and to call it the differential method. In the first or " Positive" method i the steam drives the atmosphere before it, and then loses itself entirely in it, without leaving a particle of the heat by which it had been created, to be returned into the boiler; all is lost after it has left the cylinder, and this constitutes th~ high pressure non-condensing engine. In the second or" Negative" method, the principal use of the steam is to negative or remove the pressure of the atmosphere ; the pressure of the steam may be insufficient to overcome the friction of the engine,