GETTING THE TRAIN OVER THE ROAD.
The first two miles out of Jersey City a grade of about 40 feet is ascended, but the summit is reached in four minutes; then the links are hooked up to the 8-inch cut-off, which is the ordinary running-point with this train. Next mile is passed in 85 seconds, but is finished by shutting off steam to let the engine roll over a bridge. Here the valves are oiled, a duty which is repeated three times during the trip. Although steam was shut off for only about 300 yards, the speed was perceptibly reduced; and it took a minute and a half to make the next mile. Three miles succeeding that were traversed in 3½ minutes, one of them being run in 59 seconds; but again a demand for reduced speed intervened in the shape of the street-crossings of Newark,—the city being approached by a sharp curve. Here the speed was reduced to 12 miles an hour, and two miles were run at a rate under 30 miles an hour. A spurt is again made; and the second mile, after getting clear of the street-crossings, is passed in 63 seconds, the next mile in 61 seconds, when another reduction of speed for Elizabeth streets and a railroad crossing takes place. After passing this town, a speed of one mile in 57 seconds was attained, several miles having been traversed in a minute each: then came the watering-point, where the speed was reduced under 20 miles an hour. Thus it was through the whole trip,—a struggle to get up speed: then comes the necessity for dissipating part of the power gained in raising the load to the required velocity. The engine maintained a speed of sixty miles an hour easily enough; but it was a laborious proceeding, increasing the speed in a couple of miles from a mile in two minutes to a mile in one minute. Several heavy grades were ascended, one of them three miles long, which reduced the speed in the second two miles to 30 miles an hour, although the links were dropped to ten inches cut-off. The highest speed attained during the run was a mile in 55 seconds. The greatest speed was reached with the links hooked back to cut-off at 7 inches. It is well understood by engineers running these trains, that high velocity can only be attained with the lever well notched back. Sixty miles an hour is nearly the maximum speed these engines will make cutting off at 8 inches, and the train is so heavy that the amount of steam represented by that cut-off is needed to maintain the speed on curves or slightly ascending grades. The fastest running is done under the favorable conditions of a straight, level track, or descending grade, where the engine can handle the train at 6 or 7 inches cut-off. When running over 60 miles an hour, if the lever be advanced a notch the speed will decrease; for more steam gets into the cylinders than can be exhausted at the high piston velocity, and back pressure ensues, which acts as a brake upon the engine. Even with the big driving-wheels of this locomotive, the piston-speed at 60 miles an hour is very high. In traversing a mile in one minute, the wheels make 258½ revolutions, giving a piston-speed of 1,034 feet.