f 6 SELECT EXERCISES.

24, which turns a wheel S of 63 teethround in 29 days 12 hours 45 minutes,on whose axis is an index that shewsthe days of the Moon’s age On a circleof 29s equal parts, on the plate thatcovers the wheel-wqrk.

On B, the axis of the handle, is apinion T of 8 leaves, turning a wheelU of 25 teeth, which turns anotherwheel V of the fame number and size,pn whose axis is a pinion IFof 7 leaves,turning a wheel X of 69 teeth, onwhose axis is a pinion T of 7 leaves,turning a wheel Z of 83 teeth onceround in 365 days 5 hours 48 minutes57 seconds, and carrying the Earthround the Sun in that time. For, inthis wheel are four short pillars, whoseupper ends are fixed into the lowerplate of a move able frame aaaaaaa,(Plate VI.) that turns round on a fixedupright pin in the center of the plateAAAA, and contains the above-men-tioned wheels belonging to the Earthand Moon: so that the whole frame

goes