As shown in Fig. 5, there may be applied to this engine a variable expansion of the Farcot type. The motor being a single acting one, a single valve-plate suffices. This latter is, during its travel, arrested at one end by a stop and at the other by a cam actuated by the governor. Upon the axis of this cam there is keyed a gear wheel, with an endless screw, which permits of regulating it by hand.
This engine, which runs at a pressure of from 5 to 6 kilogrammes, makes 150 revolutions per minute and weighs 2,000 kilogrammes.—Annales Industrielles.
FOOT LATHES.
We illustrate a foot lathe constructed by the Britannia Manufacturing Company, of Colchester, and specially designed for use on board ships. These lathes, says Engineering, are treble geared, in order that work which cannot usually be done without steam power may be accomplished by foot. For instance, they will turn a 24 inch wheel or plate, or take a half-inch cut off a 3 inch shaft, much heavier work than can ordinarily be done by such tools. They have 6 inch centers, gaps 7½ inches wide and 6½ inches deep, beds 4 feet 6 inches long by 8¾ inches on the face and 6 inches in depth, and weigh 14 cwt. There are three speeds on the cone pulley, 9 inches, 6 inches, and 4 inches in diameter and 1½ inches wide. The gear wheels are 9/16 inch pitch and 1½ inches wide on face. The steel leading screw is 1½ inches in diameter by ¼ inch pitch. Smaller sizes are made for torpedo boats and for places where space is limited.
ENDLESS TROUGH CONVEYER.
The endless trough conveyer is one of the latest applications of link-belting, consisting primarily of a heavy chain belt carried over a pair of wheels, and in the intermediate space a truck on which the train runs. This chain or belt is provided with pans which, as they overlap, form an endless trough. Power being applied to revolve one of the wheels, the whole belt is thereby set in motion and at once becomes an endless trough conveyer. The accompanying engraving illustrates a section of this conveyer. A few of the pans are removed, to show the construction of the links; and above this a link and coupler are shown on a larger scale. As will be seen, the link is provided with wings, to form a rigid support for the pan to be riveted to it. To reduce friction each link is provided with three rollers, as will be seen in the engraving. This outfit makes a fireproof conveyer which will handle hot ore from roasting kiln to crusher, and convey coal, broken stone, or other gritty and coarse material. The Link Belt Machinery Company, of Chicago, is now erecting for Mr. Charles E. Coffin, of Muirkirk, Md., about 450 ft. of this conveyer, which is to carry the hot roasted iron ore from the kilns on an incline of about one foot in twelve up to the crusher. This dispenses with the barrow-men, and at an expenditure of a few more horsepower becomes a faithful servant, ready for work in all weather and at all times of day or night. This company also manufactures ore elevators of any capacity, which, used in connection with this apparatus, will handle perfectly anything in the shape of coarse, gritty material. It might be added that the endless trough conveyer is no experiment. Although comparatively new in this country, the American Engineering and Mining Journal says it has been in successful operation for some time in England, the English manufacturers of link-belting having had great success with it.