Mowing is an operation generally performed by manual labour, by means of that well-known instrument, the scythe (fig. 1), which is a long, flat, curved blade of steel attached to a handle having a peculiar bend, and with two short pieces of wood attached, by which the mower swings it round with a measured sweep, cutting off the grass almost close to the ground, walking gradually forward as he mows; but of late years machines of various kinds have been invented and used for this purpose. Fig. 2 represents one which not only mows, but at the same time rolls the grass, so as to make it smooth and level. It consists of a heavy iron roller turning a large wheel, which, being united to a small one, causes it to revolve very rapidly. In connection with the small wheel is a series of four spiral knives wound round a cylinder, which cut off the grass close to the ground, throwing it up into a box placed to receive it. There are several varieties, but this is the kind made by Dray & Co., London, for mowing short grass, as in gardens and lawns. Those used for cutting long grass for hay, are exactly similar to the reaping machines. THRASHING-MACHINES. Illustration: (‡ THRASHING MACHINE.) The operation of thrashing, performed for ages by means of the “flail”--two sticks tied together and wielded by the hands, inflicting heavy blows on the bundle of corn spread on the thrashing-floor, so as to separate the grains from the ear--is now being rapidly superseded by the thrashing-machine. It is a sort of box having a cylinder inside with an iron wheel at each end united by bars of iron; this wheel revolves by steam, causing the bars to fall upon the corn with a gliding motion, thrashing out the grain, which falls through and is received below. REAPING MACHINES. Illustration: (‡ DRAY) REAPING MACHINE. Illustration: SICKLE.