Page:The American Cyclopædia (1879) Volume XIII.djvu/229

 PEAT 219 is driven by levers under the cutter. A mass is thus loosened of 24x28 in. and perhaps 10 ft. in length. This is lifted by reversing the crank, and the mass cut with the spade into blocks. With this machine four hands will cut and lay out 3,000 cubic feet of peat daily. When peat exists as a paste or mud, sat- urated with water, it is dredged from the bottom of the bog by means of an iron scoop, like a pail with sharp upper edges, to which is fastened a long handle. The bottom is made of coarse sack- ing, so that the water may escape. The fine peat is emptied upon the ground, where more water is ab- sorbed or evaporated, so that the mass is left somewhat plastic. It is then, placed upon a drying bed enclosed by boards 14 in. wide set on edges. As the peat cracks on the surface by further drying, it is compressed with a mallet or flail or by being trodden by men who have flat boards attached to their feet. The mass is thus reduced to FIG 2 a continuous sheet of half its for- irish siane. mer thickness, and becomes too firm to receive the impression of a man's foot. After it is cut into blocks, every alternate block is placed crosswise upon the other, air is admitted to the whole, and the blocks are rapidly dried. Peat that cannot be cut, and yet is not so saturated with water as to make mud, is often worked into a paste and moulded into blocks, which when dried become very firm. This is called hand peat or moulded peat. The mechanical preparation of peat may be effected by pressure, by drying, and by the two combined. Fresh peat has been pressed by direct pressure and between rollers. The latter method is the more effective ; but while simple pressure will bring the material into smaller bulk, if it be fibrous and light it is also elastic, and when the pressure is removed it acquires again much of its original volume. At Neu- stadt, in Hanover, a fibrous peat has been prepared for metallurgi- cal purposes by passing it through iron rollers; it was reduced two thirds in bulk, burned more regu- larly, gave a coherent coal, and withstood carriage better. On the whole, methods which rely upon pressure alone have not been suc- cessful. Other methods reduce the peat to a pulp by grinding it in a sort of pug mill, and then moulding and drying the purified pulp either in sheds, in the open air, or by artificial means. The inventor of the original process was Weber of Staltach in Bavaria. His ma- chine and process have undergone many modi- fications both in Europe and America. In this country, Mr. T. II. Leavitt of Boston has patented machinery which operates essentially after the plan of Weber, the hot drying omitted. The apparatus consists principally of a strong box 3 ft. square and 6 ft. high, supported upon a stout framework about 4 ft. above the floor of a suitable building, which should be near the bog, and is best constructed on a side hill, so that easy access can be had to the lower story on one side from the foot of the hill, and to the second story on the other side. The top of the tank should be open, and even with the floor of the second story, so that the raw peat can be dumped directly into it, as represented in fig. 3. Within the tank, and firmly fixed to its sides, are numerous projec- tions of a variety of forms, adapted to the treatment of the material in its several stages as it passes through the mill, which is divided into three apartments; through the centre of the tank revolves an upright, to which are affixed knives and arms varying in form and structure to correspond to the stationary pro- jections in each apartment ; below the tank is a receiver or hopper; and under this is a moulding or forming machine, 2 ft. wide and 12 ft. long, of simple construction, which re- ceives the condensed material from the hopper FIG. 3. Leavitfs Peat Machine. and delivers it in blocks of any desired form and size. The whole is adapted to be driven by a small steam engine, and requires about six and ten horse power respectively for the