Page:Popular Science Monthly Volume 91.djvu/399

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Popular Science Monthly

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��Cleaning the Air Fed to Automobile Engine Cylinders

OF interest to every automobilist, and to the Government whose army trucks run in con- voys almost hidden in clouds of dust, is the car- bureter air-cleaner shown in the illustration below. The device is distin- guished by its simplicity; for it has no moving parts. By extracting the dirt and grit from the* air sucked through the car- bureter into the engine cylinders, excessive wear on pistons and piston rings is avoided, as well as scoring of the cylinders, pitting of the valves and cutting out of bearings.

The cleaner operates on the principle of centrifugal action. The air is sucked in near the top and down through the two curved square - sectioned tubes. The circular path of the air down through the tubes throws the heavier particles of dust to the out- / side so that .

when air and A,rm dirt are sucked through the ends of the tubes, the dirt drops down on to a cone- shaped shield in the bottom while the air passes up and out through the center of the top to the engine cylinders. The dirt slides down off the cone into a pocket beneath, which is cleaned out as re- quired when the engine is stopped.

Another point in favor of such a cleaner is that it reduces the carbon forma- tion. The dried out lubricant remaining in the cylinder after each explosion attracts the particles of dirt usually sucked in with the fuel air, forming points on which carbon readily collects.

���In circle: Smoking the rifle sight for use when firing in the sunlight. Above: Using the rifle strap as a sling-grip

Some Rifle-Firing "Kinks" That Are Taught the West Pointers

THE average recruit who starts in at West Point knows as much about the fine points of rifle firing as a long- shoreman about flying. First he masters the elementary steps — the manual of arms and the cor- rect firing positions. Then he must learn a thousand facts not mentioned in the "Drill Regula- tions." Among the rifle kinks, for instance, is the smoking of the glass rifle sights for work in the sun. By simply holding the sights over the flame of a match — or better, over an alcohol flame — a light layer of lampblack is spread over the sight which enables the soldier to fire even when he is directly facing the sun. And when his back is to- wards the sun, the reflected glare is eliminated so that he can work without danger to his eyes.

Another kink is the doub- ling up of the ordinary rifle- strap in order to use it to ob- tain a sling-grip. By making the sling short enough, it is possible for the left hand to obtain a vise-like grip on the rifle. This helps consider- ably in steadying it.

���Air drawn to carbureter'

��Dirt falls to bottom

��Clean out The principle of centrifugal action explains the working of the carbureter air-cleaner

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