A narrow gauge railroad runs from the refinery out upon and halfway across the lake. Then it swings back in a great loop to the shore. Little cars run on the tracks drawn by a wire cable guided by rollers between the rails. Here and there, near the line, you may see workmen digging asphalt and loading trains of cars. When these are filled they are drawn around the loop to the refinery; or to the pier where asphalt in its crude form is shipped to the United States and to nearly every other civilized country in the world. The loaded cars are halted under a conveyor cable. Very rapidly the hooks which swing from the cable are thrown into place, and the big bucket is lifted from the truck and goes off down the hill. The carriers are clamped to the moving cable, all the buckets moving along at the same rate of speed. The weight of those going down helps to pull the empties back again, so that not very much power is needed to keep the cable moving. Most of the cars, however, are stopped at the refinery, which is at the edge of the lake, close to the power house and the shops. Refining Trinidad asphalt consists mainly of driving off twenty-nine per cent. of contained water. The crude asphalt is dumped into large tanks heated by coils of steam pipes. The asphalt softens and boils, evaporating the water completely. The melted asphalt is drawn into barrels, in which it is shipped away. This refined Trinidad Lake Asphalt contains all of the constituents of the crude asphalt that are valuable from the chemical or commercial viewpoint. [Illustration: Panoramic view of Trinidad Asphalt Lake. The lake occupies a bowl-like depression, in area about 114 acres. It is bordered by low hills. The surface is dotted with clumps of trees and bushes, and broken by irregular pools of surface water. In the background to the left is part of the asphalt refinery, which extends from the hilltop to the edge of the lake] Digging the asphalt is a simple operation. A mattock is the only tool required, and under its blows the asphalt breaks readily. The negroes employed in digging are skilled in the work, and break out lumps that would be far too heavy for an untrained laborer to carry. An astonishingly small amount of the material is broken into pieces. A laborer simply lifts one or two lumps, raises them up on his head, walks a few yards, and drops them in the car. The crude asphalt as broken out is brownish, usually quite wet with surface water, and filled with cavities made by gas up to an inch or more in diameter.