Page:Popular Science Monthly Volume 90.djvu/945

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Popular Science Monthly

��929

��A Convenient Method of Handling Dangerous Acids

ACIDS are, at best, a nuisance to handle. x\. The arrangement shown in the illus- tration, however, solves the problem. The original carboy of acid is ^^^^^

shown at A, and 5 is a ^

bottle with a stop-cock at the base and a tightly fitted two-hole rubber stopper in the mouth. The two are connected by a glass tube C. The tube passes from the bottle B down through a loose cover D placed on the car- boy to keep out dust and dirt. It should reach to the bottom of the carboy and be slightly bent at the lower end to allow the acid to flow out freely. The short glass tube in the bottle B, is connected by rubber tubing to an aspirator or suction pump.

Starting the suction pump reduces the pressure in the bottle B, and the acid is forced up into it by the external pressure of the air upon the surface of the acid in the carboy. Thus, the acid is caught and held in a closed vessel, from which it may be conveniently drawn off as desired, without waste or danger. No in- jurious fumes escape into the room and there is no possibility of burns being received from splashing, as the containers are not moved until they are empty. The acid is kept clean also.

���removed carboys suction

��Fine Aluminum Filings Make a Violent Explosive

THAT aluminum filings, made Into a fine powder, form parts of two of the most destructive agents is little known. It has been used in the Austrian shells as a component of the high explosive agent. This explosive is known as ammonal, a rnixture of five or eight parts ammonium nitrate and one part of finely powdered aluminum. Its explosive violence ig tre- mendous. It is one of the few explosives that have never been used as propellants. No gun known to warfare could resist its suddenness. For this reason it is used only in projectiles.

��Uncleanliness the Trouble-Maker for the Vulcanizer

REPAIRMEN are often puzzled when a . tire taken from one mold looks better than one cured at the same time in another mold. Both operations may have been performed in the same way, yet the results were different.

A dusty finger print, drop of moisture, a little oil from a tool, an insufficiently ce- mented spot at the edge of a patch, a tiny smooth space missed by the buffer — any one of these may have caused the difference.

Cleanliness and carefulness are always the first requisites for successful results, and the repairman who always inspects his work carefully after each operation, is the most likely to find the little trouble-makers before it is too late.

��A Screen Door with a Special Exit for Flies

THE fact that a fly will walk over the entire surface of a screen sometimes trying to get out, led to the experiment which resulted in the exit attachment shown in the sketch. An ordinary screen was used in its construction and an outlet formed 6 in. from the top. The screen was placed in the window with the exit-opening pointing outward so that the fly in his travels would walk out. The screen is cut and a V-shaped extension applied. The small end has an opening large enough for the fly to pass out easily.

���The projecting part shown at the top allows the flies to pass out but they cannot return

This device is valuable because it allows the flies within a room to escape and pre- vents their return. — C. H. Thomas.

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