The slope mine differs from the drift mine in that it enters the ground at an angle to strike the coal vein. The angle is usually about 45 degrees, and the cars are lowered into and hauled out of the pit on this inclined plane. The mouth of the mine is always decorated by a tall, gloomy-looking engine house, from whose portals, like the web from the body of the spider, stretches the long wire cable down into the dark depths below. There is a constant rattle of machinery. First comes the snarling clang of a bell. The swarthy engineer throws over the huge lever, and the big drum begins to revolve, slowly at first but with increasing pace until without warning a “trip” of coal pops up out of the blackness of the pit, with one or two miners clinging to the cars, their begrimed eyes blinking in the sunshine, and their little oil lamps flaring and flickering in the day breezes.
The slope mines are generally provided with a double track, letting down an empty trip and hauling up a loaded one at the same time. Next to the drift mines they are the most numerous in the Connellsville region. They do not require such heavy machinery as a shaft mine, and are not so expensive to operate. But they do not, from their nature, drain themselves, and are under heavy expense usually for pumping. They are also more liable to be flooded than any other mine.
After the coal reaches the surface it is distributed to the ovens either by steam power, or more commonly by the effort of the patient and much-enduring mule. The ovens are usually on a lower level than the mouth of the slope, necessitating considerable trestling.
The shaft mine is the most expensive and at the same time the most imposing. Over its black yawning mouth, like a great sentinel, stands the huge hoisting house. With its small peaked roof and pointed skyward proportions and its back rapidly increasing downward, it looks in the distance like an Egyptian sphinx conchant. Nearby the engine house with its ponderous engine driving a huge double iron drum, around whose corrogated iron body winds the heavy wire cable that disappears out the end of the building into the top of the hoisting house. There it passes over a pulley and is attached to the top of the “cage” in which the coal wagons are lowered and hoisted into the shaft. There are two of these cages, one goes down while the other comes up. They are built of iron and hold but one wagon or car at a time, but they make rapid trips. It is 200 to 300 feet below. The gong strikes and the engine starts. The iron drum rattles a little and the escaping steam makes a hissing noise, but over in the hoisting house there is scarce a sound. Before the rapidly moving second hand on your watch has made the one minute lap, the loaded cage slides noiselessly up its oiled groves and stops exactly level with the platform. The car is run out, an empty one run upon the cage, and in an instant it is swallowed up again in the darkness.
The loaded car with its 40 or 45 bushels, is run out and dumped into a huge bin. At the bottom of this bin the coal is let out into the big iron larry, holding about 120 bushels,and conveyed to the ovens. The coal is handled automatically from the time it is shoveled into the pit wagon at the bottom of the shaft until it is drawn from the red-hot oven mouth in the shape of silver-gray coke. The meek and soulful mule is the constant companion of the larry. All day long he draws it up and down the fiery line of oven tops. Latterly some soft-hearted inventor, pitying his hard and hot lot, invented an endless cable system to convey the larries along the ovens. It was put in operation at the Leisenring works, but it didn’t prove a glaring success, and was abandoned. Since then it has been adopted, with some improvements, by the Moyer works. But the idea does not meet with favor. The mule and the larry seem to be made for each other. In the eyes of coke men they look pretty together, and there is a deep-rooted objection to their elimination from coke region scenery.