would be of great value if it were not for the cost of hauling or transporting it to the mill or furnaces to be worked; in many cases this is done by packing on mules' backs, hauling by teams, or sliding down chutes, as the case may require, and the cost is from 50 cents to $10 per ton per mile, according to circumstances.

During the winter months, when the snow falls to great depths in the Sierra Nevadas, it is not practicable to transport ores, except at intervals, on sleds, and consequently work has to be suspended.

The importance of a cheap and regular mode of transporting the ores from the mine to its reducing-works has called forth many ingenious arrangements by those interested in mining.

In Europe, where the Hodgson wire tramway is in use, which was

Fig. 1.

referred to in the chapter on Mining Appliances, report for 1870, some success seems to have attended these experiments. So far, the only patents

granted to American citizens in the United States have been issued to Mr. A. S. Hallidie, of San Francisco, California, for various improvements and inventions

in endless-rope ways. for transporting ores and other material over mountainous and difficult roads.

In the application of this system, the route to be followed having been determined, and in the selection of which it is better to make sharp horizontal curves than vertical ones, a peculiar pulley called a "grippulley" is placed horizontally at each end of the line, or at whatever point the motivepower is obtained.

The grip-pulley has already been referred to in the last report, (page 564,) its office being to receive the rope in its groove, and by the pressure of the rope on the clips in the circumference of

Fig. 2.

the pulley, to grip the rope and prevent it from slipping in the groove of the pulley. By referring to Figs. 1 and 2, it will be seen how this is accomplished: h, rope; i i, clips working in recesses cast in the circumference of wheel 11, and on fulcrums XX. The part K is cast separately and bolted on to the wheel after the clips are fitted.

On the line of the route, at distances of about 250 feet, but regulated by the configuration of the country, are erected strong posts with horizontal

cross-arms, sufficiently high above the ground to clear obstructions, &c. On each end of the horizontal arm is a bearing-pulley, the groove of which is semicircular, and of sufficient size to allow the rope to run in it, and covering half its circumference. Immediately over each of the bearingFig. 3.

pulleys is another pulley, smaller in diameter, the groove of which is a quarter circle, covering onefourth of the circumference of the rope. Fig. 3 shows the pulleys in position; a the upper pulley, b the lower pulley, h the

rope.

A steel-wire rope of three-fourths inch diameter is stretched along the route around the end or grippulleys, and in the grooves of the bearing-pulleys which are attached to the horizontal arins of the posts. The upper pulley, a, is placed over the bearing

pulley and rope, as shown in Fig. 3, the circumference of the two pulleys running in close contact, but having an open space sufficiently large to allow the carrier f to pass between the pulleys on their outer sides.

The ends of the steel-wire rope (made from spring-steel wire) are spliced together, forming an endless rope; and motion being imparted to it through the grip-pulley, it will travel in the direction actuated, supported at intervals by the bearing-pulleys, and retained in position between the pulleys on the horizontal arms of the posts, as shown in Fig. 3.

Fig. 4.

About 50 feet apart there are attached to the rope, by means of thin steel clasps, projecting arms also of steel, about four inches long, and of a form as shown in Fig. 4, the outer end of which is fitted with a journal and collars so as to take a suspension-bar, which hangs vertically and being at right angles to the arm, keeps it in horizontal position. c and f, Fig. 3, show this arrangement complete. It is designated as the "carrier."

For conveying an ore-sack or box holding about 150 pounds, one of these carriers is used, having a hook at the lower end of a curved suspension-rod; but when it is necessary to convey a car or self-dumping buckets, or a load greater than 200 pounds, the number of these carriers