Adjusting the diaphragm contact on the ratchet wheel will change the tone of the horn.—Contributed by P. Mertz, Jamaica, L. I.
Retarder for Plaster of Paris
When it is desired to lengthen the time of setting after preparing plaster of Paris, dissolve 1 oz. of citric acid in water used for mixing 100 lb. of plaster, and it will retard the setting for about three hours.
An Inkwell Stopper
A good way to keep an inkwell of the type shown in the sketch clean is to place a marble over the opening. The marble keeps out flies and dust, is easily rolled aside and is no obstacle to the pen entering the well.—Contributed by James M. Kane, Doylestown, Pennsylvania.
A Grass Rake
This adaptation of an ordinary iron rake for use on a lawn was the outcome of not having a lawn rake at hand. Two spools, each 1-1/2 in. in diameter, were procured and one forced on each end tooth of the rake. The spools were forced on the teeth just far enough to allow the rake to slide on the ground and prevent the other teeth from digging out the grass. The end of the spools may be rounded and smoothed so that they will slide easily on the ground.—Contributed by H. E. Gray, Montclair, N. J.
