In a few months, however, he had a model ready. Mrs. Greene was so interested in his work and so proud of his success that she induced him to show the model and explain its working to some of her planter friends, especially those who had induced him to engage in the work. When they saw what he had done, and were convinced of the truth of what he told them,--that they could clean more cotton in a day by his machine than in many months by the old hand-picking way,--their excitement was great, and the report of the wonderful invention spread far and wide. Shall we say here what this machine was like? The principle was simple enough, and from that day to this, though the machine has been greatly improved, Whitney's first idea still holds good. It was a saw-gin then, and it is a saw-gin still. "Gin," we may say here, is short for "engine." This is the plan. There is a grid, or row of wires, set upright and so close together that the seeds will not go through the openings. Behind these is a set of circular saws, so placed that their teeth pass through the openings between the wires. When the machine is set in motion the cotton is put into a hopper, which feeds it to the grid, and the revolving saws catch the fibre or lint with their teeth and drag it through the wires. The seeds are too large to follow, so the cotton is torn loose from them and they slide down and out of the way. As the wheel turns round with its teeth full of cotton lint, a revolving brush sweeps it away so that the teeth are cleaned and ready to take up more lint. A simple principle, you may say, but it took a good head to think it out, and to it we owe the famous cotton industry of the South. But poor Whitney did not get the good from his invention that he deserved, for a terrible misfortune happened to him. Many people came to see the invention, but he kept the workshop locked, for he did not want strangers to see it till he had it finished and his patent granted. The end was, that one night some thieves broke into the shop and stole the model, and there were some machines made and in operation before the poor inventor could make another model and secure his patent. This is only one of the instances in which an inventor has been robbed of the work of his brain, and others have grown rich by it, while he has had trouble to make a living. A Mr. Miller, who afterward married Mrs. Greene, went into partnership with Whitney, and supplied him with funds, and he got out a patent in 1794. But the demand for the machines was so great that he could not begin to supply them, and the pirated machines, though they were much inferior to his perfected ones, were eagerly bought. Then his shop burned with all its contents, and that made him a bankrupt.