f air through the fuel box to the furnace. At the and no shot is lost in. the operation. The bag, which is of IMPROVED PRESSURE GAUGE. rear end of the furnace casing, opposite the fire door, is ar- leather, has a wooden bottom. The aperture for the escape The annexed engraving represents a novel… … piston of small area, whose outward motion is opposed by a This tube, when the plate, A, is placed as shown in Fig. 1, spindles of the air-supply and exhaust valves, eande’. When strong.adjustable spiral spring, and whose outer extremity registers with the aperture in the bag bottom. In the tube is…
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