At the time this more systematic mining was begun, some cheaper mode of transportation was also sought. First, a wire tram on the English system was tried, consisting of an endless wire rope, with buckets of the capacity of fifty pounds, and a stationary engine of 80-horse power at the bottom. This plan involved much trouble, and never could supply the requisite amount of clay ; and when winter came, with its extreme cold and snow, the plant was practically useless. Then the regular three-rail incline was adopted, which is in common use in this coal region, and which has worked well ever since. The only peculiarity of this incline is its great length. It is a mile and a quarter long, and the rise from the bottom to the top is 1,240 feet. Six cars run up it at a time ; three loaded ones coming down haul up the three empty ones. The rope is of steel, and five-eighths of an inch in diameter, and runs over two shrive wheels twelve feet in diameter, on each of which is a hand brake. One man to run these brakes, two men to load, one man to unhook at the bottom, and one to look after the rollers on the incline, are all that are necessary to run 100 tons of clay per day. The cars when empty weigh 1,800 pounds, and two tons of clay are loaded on each car. It takes seven minutes, on an average, to run one trip. This is said to be the longest gravity road of its kind in the world. From the bottom of this inclined plane a tramroad is built, two miles, to the factories at Mount Savage, and a substantial narrow-gauge locomotive placed upon it brings all clay direct to the factory, where it is dumped in the extensive yards, convenient to the grinding-pens.
The coal which is used at the works is obtained on the property from the coal measures above the clay. It is mined from a vein twenty-two inches thick, and is brought down to the head of the tram-road by a short incline, and there it is run in with the clay, and trains made up of both are run down to the brickyard.
Not all fire-clay works would, of course, require such ex tensive facilities for handling and transporting clay as are necessary at Mount Savage, Maryland, but wherever it is pos sible horse and mule power should be abandoned.
As steam has taken the heavy work of transporting the pro ducts of the country from the horses which formerly did the overland hauling, so it is doing now In the brick factories.
The apparatus for drawing the clay into the factory by the engine being in the first place cheaper than horses and carts, and doing the work without a driver, besides not being at ex pense when idle, it was a natural result that the winding drum and automatic dump-cars were adopted by all enterprising brick manufacturers.
To suit different demands, manufacturers of brick-making machinery usually construct two sizes of winding-drums and dump-cars, which are self-contained in substantial iron frames and which can be operated by a cord from the clay-pit or by the engineer from any point in the factory.
The frames of these machines are so constructed that they can be bolted to the upper part of the track timber, which does away with extra framing for that size. The pulley on No. machine is 36x8 inches, and should be run 450 revolutions per minute.
Weight of No. 1, with 400 feet of iron cable, 1300 pounds.
The manufacturers commonly build two standard sizes of dump-cars of good heavy timber, well ironed, and arranged to dump automatically when desired.
No. i dump-car holds 1 cubic yards of clay, while No. 2 has a capacity of but one yard of clay ; light wrought-iron T rails are employed for the cars to run on, the width of track between centres of rails being forty inches.
The bottom of the dump car is usually in two parts, hanging on chains which are attached to a bell-crank, which is keyed to a steel cross-shaft that has a lever on the outside of the car, which is held in position by a catch that hangs down between the wheels near the track. A stop fastened to the track re leases this catch and lets the bottom drop, when the car runs back, and the diggers by a pull of the lever again place the bot tom in position. This is done very quickly. Side dump-cars, arranged to dump on one or both sides, are also built to suit dif ferent localities, by The Frey-Sheckler Co., Bucyrus, 0.