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 



