504 



THE INDIA RUBBER WORLD 



[September 1, 1911. 



A wedge-shaped key-piece is inserted in the split ring and secured 

 by three cap screws. 



The Michclin Demountable Rim was one of the earliest to 

 be put to practical use, especially in speed trials. It has eight 

 wedge-bolt nuts on the front of the wheel, which are removed 

 by means of a brace socket wrench. By inserting the thin end of 

 spur lever between the removable rim and the permanent band, 

 near the highest wedge clamp and using slight leverage, the 

 clamp may be removed bodily and the rim taken off. 



The Dorian rim is in two halves which are hinged together 

 and can be expanded until the tire is secured. The attachment 

 to the wheel is made by means of wedges. The removal of four 

 of these wedges, each of which is held by a single nut, allows the 

 removal of the rim. 



The Howard Quick Demountable Rim has an expansible and 

 contractible rim that holds the tire to the wheel by friction, by 

 lugs that prevent creeping and by lock rivets devised tq prevent 

 slipping. 



The manufacturers of rims have also turned their attention to 

 the requirements of aviators. The tires used on aeroplanes are 

 so much lighter than the ordinary make and the shocks to which 

 they are subject notably in alighting, so severe, that they are 

 very liable to injury and the wise aviator recognizes the import- 

 ance of being able to promptly repair such damage. 



RUBBER TIRE PROTECTION. 



ABRASION against the road surface is the primary cause of 

 rubber tire deterioration ; subsequent unfavorable condi- 

 tions and circumstances — inadequate inflation and consequent 

 rim-cutting, punctures or cuts, bruises, sand or water-blisters, 

 etc. — which complete their destruction, are in most cases only 

 contributory factors, for which hard wear and consequent reduc- 

 tion of rubber substance, has prepared the way. 



Under these circumstances it is only to be expected that the 

 efforts of inventors to perfect some device, whereby, without 

 impairment of its resiliency, a tire would be guarded against 

 this destructive wear, should be watched with interest by auto- 

 mobilists, especially where it is found practicable to combine, 

 with such protection, anti-skidding properties. 



The means thus far employed for this purpose have varied 

 widely in character and include the hardening, by compounding 

 with different substances and otherwise, of the rubber surface 

 and the distribution over it of studs, corrugations, etc., of harder 

 rubber, the complete covering of the surface exposed to wear 

 with a supplementary leather "shoe" or strip, specially tanned 

 and treated to increase resistance to wear and the effects of 

 moisture and in some instances vulcanized to a rubber friction 

 fabric or directly to the body of the tire and made either plain 

 or studded with metal bosses. A similar device is made with a 

 rubber, in place of the leather foundation, and some inventors 

 even encase the tread of the tire in an armor of more or less 

 elastic, overlapping plates, closely resembling the "plate mail" 

 worn 'by knights of old. 



As far as their original purpose is concerned, i. e., the protec- 

 tion of the tire against excessive wear or external injury, some 

 of these devices serve their purpose admirably, but almost all 

 those of a removable character are open to objection for one 

 or all of several reasons. 



In the first place, they are liable to allow grit and sand to 

 find Its way between protector and tire, which, with the almost 

 inevitable friction, be it ever so slight, is disastrous to the rubber 

 surface, or, and this is equally objectionable, they admit water 

 between casing and covering, which, in its effect on the rubber 

 tire, is almost, if not quite as bad. There is also a tendency on 

 the part of some of these protectors to "creep" on the tire, the 

 heat engendered as a result of the consequent friction, especially 

 if moisture be also present, being particularly injurious. 



Thus, while in many respects, the separate tire protector has 

 its good points, it cannot be regarded as perfect and motorists 

 are still looking for some device that will protect this, the most 

 expensive item in their equipment. 



In the meantime, it cannot be denied, that in the case of most 

 of the applied tire protectors, their weak point is to be sought, 

 not in the protective medium itself, but in the means of securing 

 It in place and it is to the improvement of this feature that the 

 inventor must direct his ingenuity, if he wishes to obtain a satis- 

 factory measure of success. 



INDIA-RUBBER GOODS IN COMMERCE. 



EXPOETS FEOM THE UNITED STATES. 



nPHE following is an ofticial statement of the value of exports 

 '■ of manufactures of india-rubber and gutta-percha from 

 the United States, for ten fiscal years, ending June 30 : 



Belting, 



packing 



Years. and hose. 



1910-11 $2,163,416 



1909-10 1.960.825 



1908-09 1,498,445 



1907-08 1.347.775 



1906-07 1,253.369 



1905-06 1,221,159 



1904-05 994,100 



1903-04 879,476 



1902-03 819,985 



1901-02 634,146 



Exports of rubber boots and shoes (in pairs) have been as fol- 

 lows, by fiscal years ending June 30 : 

 Years. 



1902 2,594,708 



1903 2.307,401 



1904 2,310,808 



1905 2,390,539 



1906 2,693,670 



1907 2,310.420 



1908 3,080,253 



1909 2,396,435 



1910 3,791,084 



1911 3,984,312 



Exports (in value) of reclaimed rubber and of waste rubber 

 have been as follows : 



Years. Reclaimed. Waste. 



1910-11 $781,650 $723,664 



1909-10 535,795 578,944 



1908-09 414,861 402,897 



1907-08 418,738 449,727 



1906-07 665,109 548,695 



1905-06 511,843 339,507 



1904-05 522,902 204,945 



IHPOHTS INTO THE UNITED STATES. 



Years. 



1910-11 $875,125 $61,283 $936,408 



1909-10 1,154,347 80,567 1,234,914 



1908-09 1,391,770 71,819 1,463,589 



1907-08 1,956.590 93,545 2,050,135 



1906-07 2,262,783 191 ,064 2,453,847 



1905-06 1,992.413 208,172 2,200.585 



1904-05 1,389,064 117,735 1,506,799 



1903-04 821,562 335,480 1,157,042 



1902-03 665.972 225,198 891,170 



1901-02 449,756 127,780 557,536 



CHEAT BRITAIN AND IRELAND. 



Official statement of exports of manufactures of caoutchouc 

 for the first six months of three years : 



1909. 1910. 1911. 



Boots and shoes £78,742 £86,988 £69,376 



All others 755,903 897,199 961,804 



Total value £,834.645 



In U. S. money $4,061,800 



£984,187 

 $4,789,546 



£1,031,180 

 $5,018,237 



Value of "Apparel" waterproofed by any process — first six months of 

 the year: In 1909, £125,466; in 1910, f221,370, and in 1911, £302,059. 



Exports of rubber footwear amounted to 79,814 dozen pairs in 1909; 

 83,106 dozen pairs in 1910, and 66,521 dozen pairs in 1911. 



