456 



Popular Science Monthly 



A dustguard is made from the canvas 

 piece as shown at B. This is cut large 

 enough so that a seam at the edge may 

 be made for holding the % ^^- rod, which 

 is drilled, or a turn is put in at the right 



Details of the parts for making a seat 

 over the rear wheel of a motorcycle 



place for fastening it to the mudguard 

 and seat-frame. The upper edge of the 

 canvas is tacked to the lower board of 

 the seat. The lower edge is tacked to a 

 small piece which is used as a footboard. 



When these parts are finished, it is 

 ready for the leatherette covering. This 

 is fastened with tacks having leatherette- 

 covered heads. Horsehair is packed in 

 between the leatherette covering and the 

 seat-board to form a cushion. The 

 leatherette is tacked to the upper board 

 and all surplus edges are cut away, 

 leaving only enough for a flap over the 

 rear opening between the boards where 

 there is space for tools. This flap 

 has some gimp binding sewed to its 

 lower edge to keep the material from 

 fraying. Two eyelets are made and 

 buttons are attached to the wood so that 

 the flap may be used to keep tools from 

 falling out. 



The seat is finished with a ^-in. brass 

 rail, which must be bent in the shape 

 shown and attached with screws to the 

 edge of the upper board. A rubber foot 

 pad attached to the footboard adds to the 

 appearance of the seat — Ray E. Stewart. 



Chemical Composition to Make 

 Uninflamraiable Benzene 



ONE of the most extensively used 

 cleaning mixtures on the market 

 has its wide sale because it is not inflam- 

 mable as benzene and similar products are. 

 It is practically nothing but a mixture of 

 benzene and carbon tetrachloride which 

 when mixed in certain proportions will 

 not burn or explode when a match is 

 applied to the mouth of the container. 



It was found that the best results were 

 obtained when these two substances were 

 mixed in the proportion of nine parts, by 

 volume, of carbon tetrachloride to one 

 part of benzine. This mixture does not 

 detract from the cleansing properties of 

 the benzene but rather adds to them. 



A Leaky Tire Valve and Its Method 

 of Repair 



A LEAKY valve is the cause of many 

 a flat tire, but the valve itself is not 

 always at fault. Very often, even after 

 a new "insert" (the inside part or valve 

 proper) is bought and put in, the slow 

 leak is as bad as ever. The trouble is in 

 the rubber gasket inside the cap. This 

 becomes displaced and swung around so 

 that it presses on the stem and causes 

 the air to pass out slowly. The motorist 

 naturally screws the cap down tighter in 

 an attempt to stop the leak which only 

 aggravates the trouble. Straightening 

 the cap will effectually stop the leakage. 



Cements for Securely Fastening 

 Celluloid Parts 



CELLULOID scrapings dissolved in 

 acetone make a very good cement. 

 The resultant solution should be heated 

 slightly to clear it up. Another satisfac- 

 tory way is to moisten the two surfaces 

 with ordinary wood alcohol and press a 

 weight over them. Shavings of vulcanite 

 dissolved in sulphuric ether also serve 

 the same purpose. 



Making a Substitute for Brass 

 Paper Weights 



A LARGE corporation recently made 

 a canvass of its oflices and collected 

 all of the brass paper weights for the metal, 

 .^ In order to supply 



' %ood P'^P®^ weights to 



Wood-, . , '.screw take the place of 



I "^ V those collected, 



j l> ',|\ ^ one was devised 



coi,t iror,^"^'^ ^>iht7d^ that is inexpen- 



(jiued on sive. Ornamental 



Wooden covering for ^nd useful. The 



a metal paper weight ^^^^ -^ ^^^^ ^j 



wood, which is turned in a lathe. A 

 recess is made in the bottom, in which 

 a piece of cast iron is held in place with 

 a wood screw. — J, R, MiNTER. 



