« iepriekšējāTurpināt »
the Nat. Inst. for Promotion of Sci., Washington, &c. &c. &c.
SEARS C. WALKER.
THOMPSON S. BROWN, C. E.
WILLIAM H. EMORY, U. S. Top. Eng.
ELLWOOD MORRIS, C. E.
For Mining and Metallurgy.
Cost of Transportation on Railroads. By CHARLES ELLET,Jr.,C.E.
(Continued from Vol. VI, page 370.) I propose now to continue to produce those details of the cost of transportation on railroads, which enter into the approximate formula for the computation of the average annual charges, preparatory to the indication of certain modifications, which, in time, will be found necessary, in order to adapt the expression more strictly to the various cases which occur in practice. A reference to the table contained in a previous number of this journal, (vol. vi. p. 323) will show with what accuracy the formula, in its present state, applies to almost every variety of roads in the Union.
But it will occur to the experienced reader, that there are certain sections of the country on which the cost of fuel is exceedingly light; others where it is very great; that there are some lines provided with a double track; some on which the engines are unusually large, or on which the company are exposed to peculiar causes of expenditure. It will be readily conceded, therefore, that a formula strictly applicable to all these cases, ought to be expressed in more terms than the mere length of the line, the tonnage, the travel, and the miles run by the locomotive engines—which are all the quantities that appear in the rule which has been presented. But yet we have seen that that formula, as it is, does apply and give consistent results, and results quite close enough for almost any useful practical purpose, without any correction for these varying conditions. This circumstance, therefore, needs explanation; but before explanation can be advantageously
Vol. VII, 3RD SERIES. No. 1. JANUARY, 1844.