J. Mynde sc.
The great wheel I, fixed on the arbor K, turns the pinion c, on the arbor of which the crank d (to move the ventilator), and the fly e (to help the motion), are fixed. The pinion c, is turned three times by each alternate motion of the lever; which may be increased, or diminished, according to the number of teeth in the pinion c.
The number of teeth in the wheel A is sixty-six, but need not be toothed above half way. Instead of this wheel there might be a barrel, with a chord round it, fixed at each end of the arch of the lever, and projecting somewhat from it; which, by the motion of the lever, would work in the same manner in other respects, and be easier made, and at less expence.
The wheel D fixed to the rochet C has thirty-three teeth, and its pinion G eleven.
The wheel F fixed on the arbor K has twenty-four teeth, and its pinion H sixteen.
The greater the number of teeth in the rochets, the better.
[Tab. 26.] contains the plan (in parts) of the whole machine, except the lever B and fly e, which are in [Tab. 27.]
[Tab. 27.] also contains the elevation of the arbor, with its different fixtures; viz.
| Fig. 1. | The rochet C and wheel D ([Tab. 26.]) fixed together. |
| 2. | The outside wheel F that works the pinion-wheel H ([Tab. 26]). |
| 3. | The two pinion-wheels H and G ([Tab. 26.]) fixed on their arbor. |
| 4. | The same fixed to the wheel A ([Tab. 26.]) by means of two cocks u and w ([Tab. 26.]). |
| 5. | The arbor, with the wheel L and rochet E fixed; t the place, where the wheel A is fixed. |
| 6. | The elevation of the whole arbor. |
[Tab. 28.] The elevation of the whole machine, the lever B ([Tab. 27.]) working the wheel A ([Tab. 26]).