About the year 1855, James G. Gibbs heard of the Grover and Baker machine, and having a turn for mechanics, began to ponder over how the action described was produced. He got an illustration, but could make nothing of it, and not for a year did he obtain sight of a Singer machine at work. As in the case of Singer with Wilson's machine, so Gibbs thought he could improve on Singer's, and turn out one less ponderous and complicated. He set to work, and in a very short time took out a patent for a new lock-stitch machine. But he was not satisfied with this, and experimented away, with an idea of making a chain-stitch by means of a revolving looper. This idea he eventually put into practical form, and took out a patent for the first chain-stitch sewing-machine. Since the days of Elias Howe, the number of patents taken out for sewing-machines has been legion--certainly not less than one thousand--and probably no labour-saving appliance has received more attention at the hands both of inventors and of the general public. There is scarcely a household in the land now, however humble, without a sewing-machine of some sort, and in factories and warehouses they are to be numbered by the thousand. Some machinists have directed their ingenuity to the reduction of wear and tear, others to the reduction of noise, others to acceleration of speed, others to appliances for supplying the machine in a variety of ways, others for adapting it to various complicated processes of stitching and embroidering. Some users prefer the lock-stitch, and some the chain-stitch principle, and each system has its peculiar advantages according to the character of the work to be sewn. A recent development is a combination of both principles in one machine. Mr Edward Kohler patented a machine which will produce either a lock-stitch or a chain-stitch, as may be desired, and an embroidery stitch as well. By a very ingenious contrivance the machinery is altered by the simple movement of a button, and (when the chain-stitch is required) the taking out of the bobbin from the shuttle. If the embroidery stitch is wanted, the button is turned without removing the bobbin, and the lock-stitch and chain-stitch are combined in one new stitch, with which very elaborate effects can be produced. It is said that the Kohler principle can be easily adapted to all, or most, existing machines. [Illustration] CHAPTER IV. WOOL AND COTTON. WOOL.--What is Wool?--Chemical Composition--Fibre--Antiquity of Shepherd Life--Varieties of Sheep--Introduction into Australia--Spanish Merino--Wool Wealth of Australia--Imports and Exports of Wool and Woollen Produce--Woollen Manufacture. COTTON.--Cotton Plant in the East--Mandeville's Fables about Cotton--Cotton in Persia, Arabia, and Egypt--Columbus finds Cotton-yarn and Thread in 1492--In Africa--Manufacture of Cloth in England--The American Cotton Plant. WOOL.