Before leaving this branch of the subject the lawn-mower should not be overlooked, with its spiral blades on a revolving cylinder, a hand lever by which it can be pushed over a lawn and the grass cut as smooth as the green rug upon a lady’s chamber. It is the law of inventions that one invention necessitates and generates another. Thus the vastly increased facilities for cutting grass necessitated new means for taking care of it when cut. And these new means were the hay tedder to stir it, the horse hay-rake, the great hay-forks to load, and the hay-stackers. Harvesters for grass and grain have been supplemented by Corn, Cotton, Potato and Flax Harvesters. The threshing-floor still resounds to the flail as the grain is beaten from the heads of the stalks. Men and horses still tread it out, the wooden drag and the heavy wain with its gang of wheels, and all the old methods of threshing familiar to the Egyptians and later among the Romans may still be found in use in different portions of the world. Menzies of Scotland, about the middle of the eighteenth century, was the first to invent a threshing machine. It was unsuccessful. Then came Leckie, of Stirlingshire, who improved it. But the type of the modern threshing machine was the invention of a Scotchman, one Meikle, of Tyningham, East Lothian, in 1786. Meikle threw the grain on to an inclined board, from whence it was fed between two fluted rollers to a cylinder armed with blades which beat it, thence to a second beating cylinder operating over a concave grating through which the loosened grain fell to a receptacle beneath; thence the straw was carried over a third beating cylinder which loosened the straw and shook out the remaining grain to the same receptacle, and the beaten straw was then carried out of the machine. Meikle added many improvements, among which was a fan-mill by which the grain was separated and cleaned from both straw and chaff. This machine, completed and perfected about the year 1800, has seen no departure in principle in England, and in the United States the principal change has been the substitution of a spiked drum running at a higher speed for Meikle’s beater drum armed with blades.