COTTON CULTTTEE. 47 



with its thousands of little saw teeth, upon bearings, and 

 let it revolve, bringing a considerable mass of cotton in 

 the seed to press against these teeth. It is easy to see that, 

 if the cylinder revolves rapidly, the teeth must very soon 

 pull off the lint from the seeds to which it is attached. 

 These teeth play between steel bars, which allow the lint, 

 but not the seed to pass. 



Now below the saws fit a set of stiff brushes upon an- 

 other cylinder, and let them revolve in the opposite direc- 

 tion. Their effect will be to brush off and clear away 

 from the saw-teeth of the cylinder the lint which they 

 have just pulled from the seed/ You need now a fan, re- 

 volving so as to -make a blast of air, in order to throw the 

 light and downy lint, which has thus been liberated, to a 

 convenient distance from the revolving saws and brushes. 



These three are the essential parts of the Whitney cot- 

 ton-gin. All the rest is cabinet work. A number of im- 

 provements have, of late years, been made in this machine, 

 the effect of which is to pick the cotton more perfectly 

 from the seed, to prevent the teeth from cutting the 

 staple, and to give greater regularity to its operations. 

 But when you have purchased a gin, the principal consid- 

 eration will be, how to place it in such a way that the 

 cotton may be brought to it with the least labor, and how 

 the lint may be taken to the screw, or other arrangement 

 for pressing, with the greatest convenience. 



The power for driving the gin is produced by two or 

 more horses acting on an upright, which revolves on an 

 iron pivot. Horizontal arms extend, say, ten feet. There 

 are, usually, four of these arms, to which the horses are 

 attached. At the upper end of this vertical revolving 

 shaft, is a large cog-wheel, say twenty feet in diameter, 

 the teeth of which play into a ratchet wheel, to the axle 

 of which a large drum is attached. This gearing gives 

 sufficient rapidity of motion to the drum, from which a 

 band passes directly to the gin. 



