“Third Mile” Type of Smoke-House.
In essence the design consists of a building, having two storeys for rubber-drying, and a shallow inverted pyramidal base, ending on the ground in “Third Mile” furnace, already described and illustrated.
It will be seen that the principles of ventilation employed are those indicated for an ordinary house—viz., air-inlet near the ground (with little draught), and smoke-vent at the roof-ridge. The windows shown in the drawing are only for purposes of inspection of the rubber during the day, and form no part of the scheme of ventilation during the hours of smoking.
It is claimed that the efficiency of the house is high. Certainly the work of attending to the furnaces is simplified, and there should be small ground for excuse if negligence is displayed.
Jackson House.—This was brought into notice under the description of the “Jackson Cabinet,” and it was claimed that average sheets could be dried in a few days. It consisted of a small house of one storey, having several tiers of racks. Smoke and heat were generated in a small stove placed outside the wall. A smoke vent was provided in the roof. These cabinets had a certain vogue as part of a small unit installation, with a fair degree of success. It is not clear, however, that such speed in drying is required. (This point will receive further attention in a [subsequent chapter].)
“Devon” Type.—In its full original design this type owes its origin to Mr. H. E. Nixon, General Manager of the Devon Estates, Malacca, where it forms part of unit divisional installations worked under a scheme of decentralisation.
The original units consisted of a building erected with an iron framework covered with sheets of asbestos-slate, and a roof of galvanised iron.
The novelty in design lies in the utilisation of external platforms upon which the racks of bars supporting the sheets of rubber may be drawn out of the smoking chambers, and on which the racks are loaded and unloaded. By this device it is possible to remove the contents of any compartment bodily without interfering with the continuity of curing in the other compartments. That is to say, smoking in such a house can proceed day and night if necessary, and yet the rubber in any part of the house can be examined, can be removed, or can be replaced without cessation of smoking.
It will be seen from the illustrations that the house is more or less of the same general design as the “Third Mile” type, with the addition of external platforms. It has two storeys for the reception of rubber; and a basal furnace-room with sloping sides converging downwards into a pit containing a large drum-furnace. This is mounted on a low truck, and travels on a short length of railway.