TOUCHSTONE'S DIAL

The Ring Dial, perhaps the most elegant in principle of all the forms of sun dial, has not, I think, fallen into greater disuse than have sun dials of other constructions. To describe, in this place, a modern ring dial, and the method of using it, would be useless: because it is an instrument which may be so readily inspected in the shops of most of the London opticians. Messrs. Troughton and Simms, of Fleet Street, make ring dials to a pattern of about six inches in diameter, costing, in a case, 2*l*. 5*s*. They are, in truth, elegant and instructive astronomical toys, to say the least of the…