Page:Popular Science Monthly Volume 89.djvu/608

 594

��Popular Science Monthly

��certained. The front wheels are the worst offenders and if the wheels "toe- in" or out unduly, rapid tire depreciation is unavoidable because the wheels do not roll freely and the tires ha^•e a combined rolling and sliding action which is very destructi\'e to the treads. The method of using this hxlure is also clearlv outlined.

��Accelerating the Cooling Water Circulation

THE engines of many popular light automobiles are cooled by the natural or thermo-syphon system of water circulation, which depends upon the displacement of hot water in the water-jacket by heavier, cooler water from the radiator. This method of circulation gives good results, but some favor the more positi\'e and faster movement of the cooling liquid such as is produced by the use of a pump.

I'nfortunateh', it is not alwa>-s pos- sible to instal a pump in a s\stem designed for natural circulation. The flow of water ma\' be accelerated by the simple dcN'ice shown in the illustration. One of the water-pipes is fitted with a

��BALL CHECv

���An arranKcmcnt for qiiickcnini; tlic- cool water circulation by an injector action

tube so thai liu- enclosed end jjoinis uji and on the outside carries a nozzle con- nected In I he exhaust manifold b\' a tube at Lulled 111 .1 ball-clu'ck fitting. At every explosion an easih' variable <|uanlity of gas is by-passed to the

��nozzle and circulation is quickened by an injector action. The check-\alve is necessary to prevent water being drawn back into the engine should it backfire. .Arrows show the direction of gas and water. — \'. W. Page.

���By loosening the outer set- screw the blade is adjusted

��A Pencil Sharpener with an Adjustable Blade

M.WV persons find it a serious ob- jection to pencil sharpeners that it is impossible to get a sufificient length of point on a pen- c i 1, the sharpen- ers ordin- arily cut- ting the lead at the same taper as

the wood, bringing it to a point only a short distance beyond.

A pencil point of any length ma>- be obtained by the use of one of the familiar forms of sharpeners such as il- lustrated, in which the blade is adjust- aiile by means of set-screws at each end, the cutting edge of the blade extending across the axis of the pencil.

By loosening the outermost set-screw and m\ing that end of the blade out- wardly to a slight extent, as indicated b\- the dotted line, the lead is allowed to pass the blade without being cut. and the thickness of the jioint portion may be determined by the distance the blade is swung. — Christi.vn Nie:lson, Jr.

A Quick Method of Repairing a Broken or Cracked Die

PART of a broki'ii tooth on a male gear-die which was wanted in a liurr\- had to be renewed. The broken liinlh was do\etailed (after annealing) .uul a |)iece of cast steel fitted in and rdiighK- finished. It was then carefulb' iiiM/i'd and anne.ded while cooling, .\ller (doling, the brazed tooth was tinishetl with a lile and the whole die tempered as usual, care being taken not to heat enough to melt the brazing.

Tile job stood well, thousands of br.iss ge.us 1! in. thick having been jjuiicheLl with the repaired die.

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