470 



Popular Science Monthly 



% A by % in. in size, nailed thereto. The 

 two lower depending strips, arranged in 

 V-shape, are secured together at their 

 lower ends by a cross-strip which rests on 

 the keel strips, in the manner described in 



rusted from water working in around the 

 beads when the tires are run soft, or 

 through neglected cuts in the tires, or from 

 neglect to put proper fittings on the valve 

 stem, the rust should be removed with 



reference to the end frames. Pins or 

 Screws may be used to hold the seat 

 frames to the body of the canoe, but small 

 bolts are preferable for this purpose. 



The entire framework, together with the 

 Canvas and oars, can be knocked down and 

 folded in a space 6 ft. long, I ft. wide and 

 6 in. thick, and can easily be shouldered and 

 carried by a boy. The end extension 

 pieces B, swing down and rest between the 

 keel strips A . The hinges on the side bars 

 D, provide a means for swinging the end 

 pieces alongside the bars for packing 

 purposes. 



The Cause and Prevention of Rim 

 Cuts on Tires 



PROTECTION from rim cutting is not 

 afforded by any particular type of tire 

 but depends rather upon the design, quality 

 and usage. No good tire of standard type 

 will be cut by any standard rim, if properly 

 used. On the other hand, any type of tire 

 will be injured if subjected to abuse. 

 Under-inflation, dented and irregular rims, 

 excessive loads, tire fillers and stiff reliners 

 are the common causes for cutting and 

 breaking above beads. The flanges of a 

 rim may be battered down and roughened 

 as a result of a tire being used deflated for a 

 considerable distance. When another tire 

 is applied it is sure to cut above the beads. 

 Tires carrying heavier loads than those 

 for which they are designed may break at 

 the beads where they are engaged by the 

 clinchers of the rim. If rims become 



Detail of the parts for making the frame 

 in the construction of the canvas canoe 



emery paper and the rims painted with a 

 coat of aluminum, graphite and oil. 



It is not uncommon for tires to be 

 applied to rims of wrong size through a 

 mistake as to dimensions. Sometimes a 

 36 by 43^-in. tire is placed on a 36 by 4-in. 

 rim. The diameter of this rim is ap- 

 proximately 28 in. and the diameter of the 

 beads of the tire approximately 27 in. for a 

 quick detachable type, and approximately 

 26 in. for the regular clincher type, there- 

 fore it becomes necessary to stretch and 

 strain the beads considerably. Again, the 

 43^-in. beads are not constructed to fit a 

 4-in. rim, and will not engage properly in 

 the clinchers. Good results cannot be 

 secured when the beads are strained and 

 crowded in this manner. 



Trick of Passing Cigarette Smoke 

 Under Handkerchief 



PLACE an ordinary china saucer over 

 an empty glass tumbler and cover the 

 whole affair with a handkerchief. Place 

 the bundle on a table. Light a cigarette 

 and blow a few rings of smoke towards 

 the hidden tumbler. Then make a few 

 magical passes. Remove the handkerchief 

 and saucer and the smoke will be found 

 in the glass. 



To effect this you rub a few drops of 

 hydrochloric acid on the inside of the glass 

 and some ammonia on the saucer. The 

 two fumes combined produce a vapor 

 resembling cigarette smoke. 



