Hour-Glass. An hour-glass may be made thus: - Procure a cork that will fit the nocks of two oil-flasks, and make a neat hole through it with a round file. In the middle of this hole fasten a bead, or

Piece of tobacco pipe, a quarter of an inch long. Dry some common house-sand in a ladle over the (ire, and shake it through a tine sieve or muslin bag; till one of the flasks with it, fit in the cork, and invert it over a jug or the neck of a wine-bottle ; let it run for an hour; collect the sand that has passed through, pour the rest away; return, the sand to the flask, and fit in the other. Place the whole in a wooden frame for support. Egg glasses are to he made with two small phials, furnished with sand to run for three minutes. The flasks should be well dried by the fire, and the cork sealed in. If oily, they may be cleaned with a little hot water, sand, and salt of tartar.