Laths are long, thin, and narrow slips of wood nailed to the rafters of a roof to sustain the covering, or to the joists of a room, in order to support or hold up the plaistered ceiling; they are also used for light fencing and various other purposes. Laths are usually made by rending them out of fir or oak; they are made of various lengths, from 2 feet to 4 feet, and are distinguished by three different thicknesses, termed single, lath and half, and double; the latter signifying double the thickness of the single, and lath and a half the medium thickness. In the United States of America, where manual labour is at present more scarce than in this country, machinery has been employed for rending as well as for sawing out laths: there is nothing original in the latter operation, but there is apparently something worthy of notice by our countrymen in the annexed reports of American patents, which we extract from the Franklin Journal of Philadelphia.
In Rice's machine, "a slock is fixed in a frame, in which it slides freely backward and forward; it is moved by a cog-wheel, which works in cogs on one side of the stock in the manner of a rack and pinion. A knife is fixed upon the stock, and the timber to be cut into laths, etc. is fixed in a frame, and is made to bear against the stock, and the lath is cut by the traversing motion of the stock. The knife, it is said, may have a doub'e edge, so as to cut a lath both by the forward and backward motion."
Lynch's machine "consists of a long plank, which operates as a plane stock; this plank is made to slide upon its edge between upright standards upon a firm platform; a wide iron, like a plane-iron, is fixed so as to cut on one face of this plank much in the manner of the cutters of some shingle machines; the throat of the plane, if we may so call it, has other cutters standing at right angles with the first cutter, and at such distances apart as to reduce the laths to a proper width. The cutter plank is made to traverse by means of a pitman at one end, operated upon by any suitable power."