Page:Popular Science Monthly Volume 81.djvu/184

178 from petroleum oil, which contains practically no sulphur derivatives.

In proximate composition Bermudez is very similar, as far as the bitumen is concerned, to that of the Trinidad material. The proportion of malthenes is slightly larger, and the asphalt in consequence somewhat softer, but in general, it is of a very similar character.

As will be seen in the accompanying illustrations, the crude asphalt is won from the surface of the pitch lake by laborers with picks, in the form of flakes which have been mentioned. Those are thrown into

skips carried on small platform cars, which are run over the surface of the lake in a loop by cable, the rails being supported by palm-tree ties, which must be realigned almost daily, owing to the movement of the surface of the pitch. The loaded skips are brought to the terminal station at the shore of the lake, where they are hoisted and clumped into other skips, which are carried on a cable-way down the surface of the country between the lake and the shore, and out into the ocean on a pier some thousand feet in length, where they are emptied into chutes and dumped into the hold of the vessel awaiting a cargo. A thousand tons or more can be put on board a large steamer in this way in a day. During a large part of the year, three to nine vessels a day are lying off of or alongside the pier, waiting to be loaded.