Popular Science Monthly
��449
��other penwipers. The pen and pencil spaces have curved bottoms to facilitate the removal of the pencils and holders.
One side of the bottom part of the case contains a long tray with rounded bottom, partitioned off to hold different kinds of steel and other pens. The remaining space is taken up by two telescoping trays, the upper one being shallow and holding French cur\'es, protractors, etc., while the bottom tray holds the drawing instruments. When ,in use all these trays may be taken out and set at any convenient point. If the case is to be kept at the right side of the drawing-board, which is the usual place, care must be taken that the ink-bottle partition is located at the left side of the box, as shown, as the ink will be much easier to reach. — H. H. Parker.
��A Mixture for Removing Paint From Wood
SOME very satisfactory- paint removers can be made by mixing up proportions of such substances as acetone, amyl alcohol, carbon bisulphide and ethane tetrachloride. Any one of these liquids will suffice and may be applied with a brush or made up in paste form and applied with a pad. A good preparation may be had by mixing together 3^ lb. of potassium hydroxide, I pt. of acetone, 14. pt- each of methylated spirit, oil of turpentine, petroleum spirit and 5 oz. castor oil. A thin coat of this is spread over the paint surface and a few minutes later another application is made. This will soften the paint so that it can be removed with a scraper or spatula.
��Cleaning the Oil -Pump Screen on an Automobile Engine
FAULTY lubrication of an automobile engine may be traced to the clogging of the pump- screen by particles of dust and dirt from the incoming oil, with the result that a portion of the screen is defective and instead of allowing the oil to pass freely into the pump-chamber it serves as a barrier to its passage. For this reason the bearings receive an insufficient amount of oil and they become hot, causing the engine to lose power. It is necessary to remove the pump-screen and wash it thoroughly. Experience will teach the motorist that if this is done frequently, less trouble will result from improper lubrica- tion. — Adolfh Klein.
��To Make a Triangle Gage for a Cross-Section Liner
THE gaging of lines accurately for cross section work on a drawing requires some mechanical device. Lines cannot be drawn evenly spaced by dividing with a scale. The illustrations show the parts used in the construction of a cross-section
���Manner of placing t±ie triangle and gage on the drawing board against the T-square
liner which is used in connection with a T- square and triangle on a drawing board.
An old wood T-square or triangle and gages cut from brass or aluminum (pref- erably aluminum) are the necessary- parts. The binding posts taken from discarded dr>^ batter>' cells will make good thumb nuts. Cut all the slides to fit the grooves as true as possible to avoid any side motion. Make all the parts according to the details in the illustration and glue them together as designated.
To operate the liner place it on the edge
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���The parts made of an old T-sqnare with metal gages of aluminum. These are glued together
of the T-square as shown in the illustration. Adjust the gage A to the desired spacing distance on the scale and in the same man- ner adjust the gage B for a variable dis- tance. Start by placing the triangle tight
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