The Strip on the Rocker Prevents the Child Tipping the Chair Too Far Either Way
A strip, A, is fastened on the outside of the rocker with small screws so that it may be removed without injuring the chair. A rubber-covered tack driven in on the under side at each end of the strip modifies the shock and the baby can rock to its heart's content without danger of turning over.—Contributed by Mrs. G. W. Coplin, Bay City, Mich.
Homemade Countersink for Wood
A round or flat-head bolt can be made into a good rosebit or reamer for countersinking holes for screw heads. In the illustration, Fig. 1 shows a reamer made of a round-head bolt, and Fig. 2, one made of a square-head bolt. The round-head makes the best reamer as more cutters can be filed in the surface and less work is required to file it into shape.
Round and Square Heads of Bolts Shaped and Notched to Make Countersinks (Fig. 1, Fig. 2)
To Maintain a Constant Level of Liquids in Vessels
It is frequently desirable in laboratory experiments, and in practical work as well, to maintain a constant level in a tank without allowing it to become full. In many cases an outlet pipe at a certain height in the side of the tank is not desirable, and in laboratory experiments with beakers or crocks is, of course, impossible.
The diagram shows a simple but effective constant-level device. The outer end of the inverted U-tube is curved upward so that it never empties. If desired, the upward curve may be omitted and the straight end immersed in a small vessel of water. All that is necessary now for the successful working of the device is that the inner or tank end, A, of the tube be lower than the outer end—in other words, below the level of the end B—and the inner end below the level of the fluid. Of course, the U-tube must be first filled with liquid and will then act as an intermittent, never-breaking siphon. Should the tank fill above the end B, the siphon drains the fluid down to that level and no lower, even if the inner leg of the tube reach the bottom. To maintain this level against loss by evaporation some slight inflow is necessary.