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THE DIFFUSION PROCESS.steam; the direct steam becomes condensed in the coil, and pressure is madein the rubber tube by the steam acting on the condensed water.Attached to each cell or dipper is the juice heater b; this is of the verticaltube type, exhaust steam being admitted at o, and the condensed waterdrawn off at p. Communication between diffuser and juice heater maybemade either at top or bottom by the pipes k or c. The main juice circulatingpipe is shown at m, the controlling valves or cocks appearing at i. The floorlevel on which the operator stands is at the line l, all valves and cocks beingwithin easy reach; g is a small pipe let into the cover of the diffuser to act asan air vent to allow the air to escape when the diffuser is being filled.Elevators.—The other adjuncts of the diffusion battery which remainto be described are the elevator and charging apparatus ; these are very variedin design and arrangement. In case the canes are sliced on the basement,they are elevated to a floor above the level of the battery by means of an endlessscraper carrier similar to those employed to convey megass to the boilers;in other cases, the cane cutting machine is placed above the level of thediffusion battery, and the canes are elevated as such, and the sliced cane distributeddirectly from the cutting machines.Charging.—The method by means of which the cells are filled withchips varies with the arrangement of the battery; the latter may be arrangedeither as a circular or as a line battery. In the former case the cutter is placedabout twenty feet above the level of the top of the cells and directly over thecentre of the battery, or in case the canes are cut on the basement the chipsare elevated to a hopper similarly placed. The hopper or cane cutter is mountedon rollers, so that it can be revolved through a complete circle. The hopperterminates in a shoot, the discharge of which can thus be brought over any cellat will. When the cells are placed in line, the chips cut on the basement aredelivered into a truck running on an over-head line, from which pass shootsdirecting the chips to the diffusers. Line batteries are generally placed in twoparallel rows, between which is the platform on which the attendants stand.Circulation.—The water requisite for the diffusion process is containedin an overhead tank, placed considerably above the level of the diffusers. Thecirculation of juice throughout the battery is secured by means of the hydrostaticpressure obtained from the head of water in this tank. When it is desired toempty a cell of its liquid contents, this hydrostatic pressure cannot of course beused, and an air compressor, in nearly all cases, forms a part of the plant. Thelatter is used also in starting the first round of the battery, and afterwards inthe regular routine when a cell contains exhausted chips.Working of the Battery.—In Fig. 136 is given a plan of atwelve-cell line battery, arranged in two rows, showing the pipe connectionsbetween cells and heaters, and in Fig. 137 a diagrammatic sketch of a batteryintended to illustrate the method of working. Let the battery consist of twelve229