These difficulties have prevented the universal adoption of this means of slag disposal, and have caused the development of others, of which by far the most important is "granulation." This was first practiced in this country, so far as known to me, by Captain T. C. Jones, at a small blast-furnace near Lynchburg, Va., and was subsequently applied by him, and is still continued in use, at a furnace at Iron Gate, Va., where the slag is flushed directly into the James River and carried away by the current of that stream. .

The method consists in running the cinder out through a trough with a projecting end, just beneath which is placed a flat jet or nozzle about the same width as the trough. When the cinder starts to run a powerful current of water is turned into this nozzle, and the cinder running from the end of the trough falls onto this jet whose velocity is sufficient to tear it into small shot as it runs, and these, of course, are prevented from recementing by the chilling action of the water.

Most plants which use this method of slag disposal are not so located that they can flush the cinder directly into a river, and these have installed huge concrete-lined pits or tanks, sunk in the ground, into which the cinder and water from the jet fall together, and from which the cinder is recovered, generally by means of a clam-shell bucket., and loaded on to cars. It is cold by that time so that there is no danger of fire; the cinder is between coarse sand and fine gravel in size, generally rounded, and a very easy material to handle. It of course may be carried any distance desired to make fills on railroads or the like, since the time element does not enter into its disposal as it does when handled molten, and it can be bandied virtually without expense in outward bound empty cars, and has in the past been very generally handled in this way by the railroads, without charge, on account of its value to them as a filling material.

Fig. 229. Brown hoist traveling crane and grab bucket for handling cinder.

The clam-shell bucket for recovering the cinder from the pit is operated in various ways, either by an overhead crane, a crane trolley without lateral movement, or by a locomotive crane running on a standard or broad-gauge track. An arrangement of the latter kind may be seen in Fig. 228, which shows a Brown Hoisting Machinery Company crane engaged in this service. The pit cannot be seen, but its position can be judged from the ropes running from the end of the boom down to the clam shell which is out of sight in the pit, also by the steam rising from it. The granulated cinder is raised out of this pit and swung over into the hopper cars, steam from which is seen rising on the right-hand side of the picture.

Fig. 229 is a view of the same plant and crane from a different position. The pit may be distinguished by the steam rising from it at the extreme left of the picture, while the white granulated slag in the car showing just under the crane boom is plainly visible.

Fig. 230. Browning grab bucket rising out of pit, water draining off.

Fig. 230 shows a clam shell operated from a trolley on an overhead runway, installed by Victor R. Browning & Company of Cleveland. The clam shell just at the top of the pit may be clearly seen with the water contained in the slag running from it. The clam shell open, dropping into the pit, is more plainly shown by Fig. 231. In this the perforations in the bucket for allowing the water to run off are plainly visible. The clam shell in its open position with the cars of loaded slag under the runway, are clearly shown by Fig. 232.

A different design but with the same general arrangement by the same company is shown by Fig. 233. The trolley for handling the bucket with its mechanism and the operator's cage are shown by Fig. 234.

This method of handling slag has the great advantage that it gives several hours leeway, since slag can be stored in the pit without requiring to be removed for a considerable period, so that breakdowns of the slag handling apparatus may occur without necessitating the shutting down of the furnace.

Fig. 231. Browning grab bucket open over pit.

By providing a pit a little larger than common it would be very easy to store the slag for twelve hours or more, and so eliminate the operation of the slag trolley on one shift. Where the railroads take the slag, and the shifting engine is available for handling empty and loaded cars, this method is more economical for a single or even for a two-furnace plant than the liquid cinder method because it can be run by a single operator, whereas the other requires a locomotive and crew for two shifts as before stated.