The railroad tipple consists simply of a frame building from forty to sixty feet long, fifteen feet high, and from eighteen to thirty feet wide. This structure is set upon four or five plain timber bents, and its floor is usually twenty-seven feet higher than the top of the track rails which run beneath the outer end of it. A platform on this floor is so adjusted by a single shaft that, when a loaded car is pushed on it, it tips forward to an angle of about thirty degrees. The end gate of the wagon is then opened and the coal runs out on to the screen. This screen is simply a set of longitudinal iron bars inclined outwardly at distances apart of one and one half inches. All coal that passes over these bars is called “lump coal” and is run into a sheet-iron pan suspended from the scales platform, where it is weighed, and it is then dropped directly into a car standing on the track below it. The coal which passed through the first set of bars has, in the mean time, fallen on to a second screen with bars only three quarters of an inch apart. The coal that passes over these bars is called nut coal, and is also weighed and dropped into the cars, while the coal that passes through the bars is called “slack.” This is dropped into a shute, is carried by it into a car on the slack track, and is run thence to the dumping ground. When all three kinds of coal are loaded together it is called “run of mine,” while lump and nut coal together make “three quarter coal.” These tipples may, of course, be built with two sets of screens and platforms, and thus be made to do double work, and some of them are so built. Under the projecting end of the tipple there are usually four tracks; the first or outside one for box-cars, the next for lump-coal cars, the next for nut-coal cars, and the last for cars for slack. Four men operate a single railroad tipple; two dump and weigh the coal above, while the others trim and move the railroad cars on the track below. To this number a helper is often added, both above and below. Besides these men a boy is usually employed to rake the nut coal from the lower screening bars where it sticks and prevents the slack from passing through. Sometimes it takes two boys to do this work properly. Boys are also employed to push the slack with a scraper down the shutes into the car on the slack track when the elevation of the tipple above the rails is not sufficient to afford the necessary grade. Bars are being largely superseded now by revolving screens for separating slack from nut coal; they do the work far better, and make the employment of a raking boy unnecessary.