The wheel fixed on the arbor, on the outside, has twenty-four teeth, and its pinion sixteen.
The wheel, which turns the fly, has ninety teeth, and the pinion turn’d by this wheel ten.
The greater the number of teeth in the rochets, the better.
This machine may also be applied to other useful purposes at mines; and it may be easily made to turn a mill to grind corn; or to turn a wheel to raise coals, or whatever else is wanted to be raised from the mines. As I have not met with any thing of the kind described, I take the liberty of desiring you to lay it before the Society; and I hope it may be made some way useful to the public.
I am, Sir,
Your most obedient humble Servant,
Kea. Fitz-Gerald.
Poland-Street, June 7th, 1758.
Explanation of the Three Tables.
The wheel A (Tab. [26.]), which is turned by the lever B (Tab. [27.]), or rather moved up and down by it, is loose on its arbor; and likewise one of the rochets C (Tab. [26.]), and the wheel next to it D. The outside rochet E, and outside wheel F, are fixed on the arbor.
There are two pinion-wheels G and H fixed on one arbor; one on each side, near the edge of the wheel A, moved by the lever.
There are also two clicks a and b; one a fixed to the great wheel A, the other b fixed to the frame. These exclusive of the wheel I, that moves the pinion c, on the arbor of which, the crank d, and fly e, (Tab. [27.]) are fixed.