There is no nicer problem connected with the establishment of a railroad, than, having given the grades, the nature of the traffic, and the fuel to be used, to obtain therefrom by pure mechanical and chemical laws the dimensions complete for the locomotives which shall effect the transport of trains in the most economical manner; and there is no problem that, until quite lately, has been more totally neglected.[3] Of the whole cost of working a railroad about one third is chargeable to the locomotive department; from which it is plain that the most proper adaptation is well worth the careful attention of the engineer. Though it is generally considered that the proper person to select the locomotive power can be none other than a practical machinist, and though he would doubtless select the best workmanship, yet, if not acquainted with the general principles of locomotion, and aware of the character of the road and of the expected traffic, and able to judge, (not by so-called experience, but by real knowledge,) he may get machinery totally unfit for the work required of it. Indeed, American civil engineers ought to qualify themselves to equip the roads they build; for none others are so well acquainted with the road as those who from a thorough knowledge of the matter have established the grades and the curvatures. The difference between adaptation and non-adaptation will plainly be seen by the comparison below. The railway from Boston to Albany may be divided into four sections, of which the several lengths and corresponding maximum grades are as tabulated. Length in miles. Steepest grade Boston to Worcester, 44 30 Worcester to Springfield, 541/2 50 Springfield to Pittsfield, 52 83 Pittsfield to Albany, 431/2 45 A load of five hundred tons upon a grade of thirty feet per mile requires of the locomotive a drawing-power of 11,500 lbs. Upon a 50 feet grade 15,500 lbs. Upon an 83 feet grade 22,500 lbs. Upon a 45 feet grade 14,500 lbs. Now, if the engines are all alike, (as they are very nearly,) and each is able to exert a drawing-power of five thousand pounds to move a load of five hundred tons from Boston to Albany, we need as follows: B. to W.--11500/5000 or 2 engines. W. to S.--15500/5000 or 3 engines. S. to P.--22500/5000 or 5 engines. P. to A.--14500/5000 or 3 engines. From which the whole number of miles run by engines for one whole trip would be,-- B. to W. 44 miles by 2 engines, or 88 W. to S. 541/2 miles by 3 engines, or 1631/2 S. to P. 52 miles by 5 engines, or 260 P. to A. 491/2 miles by 3 engines, or 1481/2 ______ And the sum, 660