This instrument will be found by those studying the telegraph codes to give good results, equal to any of the expensive outfits sold for this purpose.—Contributed by Chas. J. La Prille, Flushing, N. Y.
Laboratory Force Filter
The sketch represents a force filter which is well adapted for use in small laboratories. The water is turned on at the faucet and draws the air through the side tube by suction, which in turn draws the air in a steady stream through the Wolff bottles. The tubes may be attached to a filter inserted in a filter bottle and filtering thus greatly facilitated. The connection to the faucet can be made, as shown in the detailed sketch, out of a long cork, by boring a hole large enough to fit the faucet through the cork and another slanting hole, joining the central hole, on the side for a pipe or tube. At the lower end of the cork a tube is also fitted, which may be drawn out to increase the suction. The inclined tube should be slightly bent at the lower end.—Contributed by W. M. Mills, Bakersfield, Cal.
A Slight Vacuum is Formed by the Water Flowing through the Cork, Which Forces the Filter
Beginner's Helper for Roller Skating
One of the most amusing as well as useful devices for a beginner on roller skates is shown in the sketch. The device is made of 3/4-in. pipe and pipe fittings, with a strip of sheet metal 1 in. wide fastened about half way down on the legs. On the bottom of each leg is fastened an ordinary furniture caster which allows the machine to roll easily on the floor. The rear is left open to allow the beginner to enter, then by grasping the top rail he is able to move about on the floor at ease, without fear of falling.—Contributed by J. H. Harris, Berkeley, Cal.
Beginner Cannot Fall