Jffonthly .Meeting of the Franklin h~stltufe. ~ 13

For the Journal of the Franklin Institute.

Economy of the Steam Engine.

In the last number of the Journal I stated the causes of loss, which were, first, insufficiency of power produced, by having an engine too small for the work to be done, or boilers too small for the engine, or from both these causes combined.

The great loss that ensues in this city from the use of too small an en- gine can hardly be estimated. Those who use them appear not to be aware of the advantages of using steam expansively; and as, in fitting up their works, first cost instead of economy of fuel has been the principal object kept in view, they go into operation with an engine much below the size required, and with boilers just sufficient to supply it with steam; and go on working steam full stroke, with their fires constantly agitated to make a sufficient supply. If they would double the size of the engine, the same steam, used expansively, would do much more work, or the same work could be done with three-fourths of the fuel; and if, in addition to this, they will add 50 per cent. to their boilers, an additional saving will be made. Two instances have occurred, to my knowledge within .the last twelve months where a great saving has been made; the first engine had three plain cylinder boilers, 30 in. diameter and 26 ft. long. They were taken out, and three of the same diameter and 36 ft. long used. With the first set of boilers, the fires required a good deal of attention to make steam; the second set makes steam ti'eelv with two-thirds of the fuel;--no change was made in the engine. In the second case, the engine had four 30-inch boilers, 2"2 feet long; four 30-inch boilers, 40 feet long, were put in their place, and a cut-offvah'e applied to the engine. The consumption of fuel was reduced from 5~r tons in 24 hours to 3~r tons, and does nearly 10 per cent. more work. I will consider the other items of loss in your next.

W.

F R A N K L I N I N S T I T U T E .

Proceedings of the Staled Alonthly .Meeting, February 21st, 1850.

Samuel V. Merriek, President, in the chair. Thomas Fletcher, Vice President. Isaac B. Garrigues, Recording Secretary. The minutes of the last meeting were read and approved. Donations were received from the Royal Irish Academy, Dublin; Win.

Jackson, Esq., Boston, Mass.; Win. M. Wadly, Esq., Savannah, Ga d the Young Men's Library Association, Cincinnati, Ohio; Thos. H. Forsyth, Esq. and Win. H. Souder, Esq., Pennsylvania Legislature; Hon. Jos. R. Chandler, U. S. Congress; Charles E. Smith, Esq., A. B. Hutton, Esq., Dr. Win. Pettit, Solomon W. Roberts, Esq., Major Hartman Bache, M. W. Baldwin, Esq., The Library Company of Philadelphia, and Prof. Jno. F. Frazer, Philadelphia.