The following table is calculated for the average of the different gauges in use, thus,—

4.7
5.0
5.5
6.0
4)21.2
Average gauge,5.3feet.
TABLE OF ELEVATION OF OUTER RAIL.
Radius of curve in feet, beingELEVATION OF OUTER RAIL IN FEET AND DECIMALS, THE VELOCITY IN MILES PER HOUR BEING
10.15.20.25.30.40.
250.130
500.070
1,000.037.079
2,000.018.040.074.111
3,000.013.026.048.074.106
4,000.009.020.037.058.079.154
5,000.007.016.031.045.065.119
6,000.006.013.024.037.053.095
7,000.005.011.021.033.046.086
8,000.004.010.018.029.039.077
10,000.003.008.010.022.032.059

CHAPTER XIV.
EQUIPMENT.

PART I.
LOCOMOTIVES.

As the locomotive engine is the power by which railroads are worked, and as its proportions and dimensions are so intimately connected with the physical character of the road, it is thought proper to take space enough at this point to examine the general principles of its construction, and of its adaptation to the work required of it upon railroads.

Under the general principles, we recognize the production and consumption of steam, the disposition of weight upon the several pairs of wheels which shall secure the necessary adhesion, the application of the power generated in the boiler to the moving of the wheels, and that general arrangement of parts which shall render the use of power economical.

BIRTH AND GROWTH OF THE LOCOMOTIVE.

294. The first idea of the application of steam to locomotion, is due to the unfortunate Solomon de Caus, of Normandy (France), who was confined in a madhouse for insisting that steam could be made to move wheeled carriages.

295. In the year 1784, William Murdoch, the friend and assistant of James Watt, built a non-condensing steam locomotive engine, on a scale of about one inch per foot, having