The Atlantic Monthly, Volume 02, No. 13, November, 1858. Various

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СКАЧАТЬ Engineers. By GEORGE L. VOSE, Civil Engineer. Boston and Cambridge: James Munroe & Company. 1857.

Baltimore and Ohio Railroad Reports, from 1830 to 1850. BENJAMIN H. LATROBE, Chief Engineer.

Railways and their Management, being a Pamphlet written by JAMES M. WHITON, ESQ., late of the Boston, Concord, and Montreal Railroad. 1856.

Report of the President, Treasurer, and General Superintendent of the New York and Erie Railroad Company to the Stockholders. March, 1856.

Final Report of JOHN A. ROEBLING, Civil Engineer on the Niagara Railway Suspension-Bridge, May, 1855.

2

Lest these statements should sound extravagant, the reader will please reckon up the amounts for himself. A bank twenty-five feet wide on top, eight hundred feet long, and two hundred and thirty feet high, would contain two million cubic yards of earth; which, at twenty-five cents per yard, would cost half a million of dollars, exclusive of a culvert to pass the river, of sixty, eighty, or one hundred feet span and seven hundred feet long. Twenty trains per day, of thirty cars each, one car holding two yards, would be twelve hundred yards per day; two million, divided by twelve hundred, gives 1,666 days.

3

The most careless observer has doubtless noticed that the front part of a locomotive rests upon the centre of a track, having four small wheels; the back and middle part, he will also remember, is borne upon large spoke wheels,—which are connected with the machinery; upon the size of these last depend the power and speed of the engine. The larger the wheels, the less the power, and the higher the velocity which may be got; again, the wheel remaining of the same size, by enlarging the dimensions of the cylinders the power is increased; and the wheels and cylinders remaining the same, by enlarging the boiler we can make stronger steam and thus increase the power. There may be seen upon the road from Boston to Springfield engines with wheels nearly seven feet in diameter, used for drawing light express-trains; while upon the roads ascending the Alleghanies may be seen wheels of only three and a half feet diameter, which are employed in drawing trains up the steep grades. Increase of steepness of grades acts upon the locomotive in the same manner as increase of actual load; as upon a level the natural tendency of the engine is to stand still, while on an incline the tendency is to roll backwards down-hill.