Take a glass and fill it to the brim with water, taking care that the surface of the water is raised a little above the edge of the glass, but not running over. Place a number of nickels or dimes on the table near the glass and ask your spectators how many coins can be put into the water without making it overflow. No doubt the reply will be that the water will run over before two coins are dropped in. But it is possible to put in ten or twelve of them. With a great deal of care the coins may be made to fall without disturbing the water, the surface of which will become more and more convex before the water overflows.
Hollow-Grinding Ice Skates
Skate Runner Fastened in Clamp
The accompanying sketch illustrates a practical method of clamping ice skates to hold them for grinding the small arc of a circle so much desired.
The U-shaped clamps are made of 3/4-in. soft steel with the opening 6 in. deep and 5 in. high and are bolted to a block of wood, 2 in. thick, 6 in. wide and 12 in. long. The skate runner is adjusted to the proper height by 1/2-in.. set and thumbscrews. The block of wood holding the clamp and skate can be pushed along on the emery-wheel table in front of the revolving wheel.
If properly adjusted, a slight concave or hollow can be made full length of the runner, true and uniform which will hold on the ice sideways and not retard the forward movement.
Contributed by Geo. A. Howe, Tarrytown, New York.