Mrs. Greene invited young Whitney to her house; as he had been disappointed in getting the place to teach, he was very glad to accept her kind invitation.  While he was there he made her an embroidery frame.  It was much better than the old one that she had been using, and she thought the maker of it was wonderfully skilful.

[Footnote 4:  General Greene:  see paragraph 140.]

179.  A talk about raising cotton, and about cotton seeds.—­Not long after this, a number of cotton-planters were at Mrs. Greene’s house.  In speaking about raising cotton they said that the man who could invent a machine for stripping off the cotton seeds from the plant would make his fortune.

For what is called raw cotton or cotton wool, as it grows in the field, has a great number of little green seeds clinging to it.  Before the cotton wool can be spun into thread and woven into cloth, those seeds must be pulled off.

[Illustration:  POD OF THE COTTON PLANT WHEN RIPE AND OPEN.  On the right a seed with the wool attached; on the left the seed after the wool has been picked off.]

At that time the planters set the negroes to do this.  When they had finished their day’s labor of gathering the cotton in the cotton field, the men, women, and children would sit down and pick off the seeds, which stick so tight that getting them off is no easy task.

[Illustration:  NEGROES GATHERING COTTON IN THE FIELD.]

After the planters had talked awhile about this work, Mrs. Greene said, “If you want a machine to do it, you should apply to my young friend, Mr. Whitney; he can make anything.”  “But,” said Mr. Whitney, “I have never seen a cotton plant or a cotton seed in my life”; for it was not the time of year then to see it growing in the fields.

180.  Whitney gets some cotton wool; he invents the cotton-gin; what that machine did.—­After the planters had gone, Eli Whitney went to Savannah and hunted about until he found, in some store or warehouse, a little cotton wool with the seeds left on it.  He took this back with him and set to work to make a machine which would strip off the seeds.

He said to himself, If I fasten some upright pieces of wire in a board, and have the wires set very close together, like the teeth of a comb, and then pull the cotton wool through the wires with my fingers, the seeds, being too large to come through, will be torn off and left behind.  He tried it, and found that the cotton wool came through without any seeds on it.  Now, said he, if I should make a wheel, and cover it with short steel teeth, shaped like hooks, those teeth would pull the cotton wool through the wires better than my fingers do, and very much faster.

[Illustration:  WHITNEY’S FIRST CONTRIVANCE FOR PULLING OFF THE COTTON SEEDS.]

He made such a wheel; it was turned by a crank; it did the work perfectly; so, in the year 1793, he had invented the machine the planters wanted.