December I, 1913. 



THE INDIA RUBBER WORLD 



127 



due to swelling or blowing of the molds is reduced to a minimum. 

 All of the machines mentioned above and many others now in 

 use in shops and foundries, were invented after the inlroduction 

 of the rubljer hose and most of tliem as a direct consequence 

 thereof; for were it not for the flexibility of rubber these tools 

 would not be in existence. In the United States there are ap- 

 proximately 30,000 machine shops and 30,000 foundries, about 

 80 per cent, of which, according to a prominent machine manu- 

 facturer, employ such tools and appliances as those mentioned 

 above. The amount of hose used in these shops for all purposes 

 varies from 100 to 1,000 feet or more, with an average of 

 approximately 300 feet. Therefore it will be seen that with 

 the 64,000 or more establishments using this hose, the amount 

 of rubber going into its manufacture for these few purposes alone 

 is by no means small. An equal amount of hose is, at certain 

 intervals of time, required for replacements, and it is gratifying 

 to the rubber industry to realize that no other substance will 

 meet the requirements and stand up under tlie alnise to which 

 rubber hose is too often subjected. 



MORE RUBBER TILING AND PAVING. 



QINCE the question of rubber tiling was dealt witli by The 

 *^ Indi.\ Rubber World in the issue of August, pages .S83 and 

 589, other instances besides those recorded at that time have 

 been quoted by the English and Colonial press. 



The opinion is freely expressed tliat with rubber at its i)resent 

 price we may look forward to its more e.xtensive use for offices 

 and for like purposes, as well as for many other uses. Tn this 

 connection the London Metal Exchange is showing the way by 

 adopting rubber as its principal flooring material, with a view 

 to deaden the noise, and enable operators to follow the bidding 

 with ease. A contract has been placed with the Leyland & Bir- 

 mingham Rubber Co. for 250 square yards, at a cost of 30s. 

 ($7.29) per square yard. The design will be of a special char- 

 acter, the ground harmonizing with the color of the walls. 



An interesting experiment was lately made at the junction of 

 the New and Old Kent Roads (one of London's most crowded 

 corners), with the rubber-capped wood blocks invented by M. 

 M. Dessau. As compared with the ordinary concrete founda- 

 tion of wood pavement the new- system is claimed to be an im- 

 provement, as the wood blocks are imbedded in an ordinary 

 asphalt grouting, while rubber caps prevent the penetration of 

 moisture into the wood. A few weeks' experience has shown no 

 disturbance under ordinary traffic. 



There is apparently no difference in the condition of the rub- 

 ber tiling of the Silvertown company, laid down eighteen years 

 ago in the large entrance hall of the "White Star Line" offices. 

 Liverpool, while the stone threshold has worn below tlie tiling 

 and required to be replaced. 



"Silvertown" tiling is used in the corridors of the new House 

 of Assembly, at Cape Town, as well as in Buckingham Palace 

 and Marlborough House, London. 



A laudable effort to use its domestic product is reported from 

 the Kuala Lumper (F. M. S) Sanitary Board, one of the 

 members expressing the opinion that it was now worth while 

 trying an experiment of paving "Jalan Raja" with ruliber. in 

 view of the present price. He agreed to provide a practical 

 test of the strength and durabiUty of plantation rubber under 

 tropical conditions. The Board decided to obtain further in- 

 formation from Singapore rubber manufacturers as to the cost 

 of producing plantation rubber blocks suitable for the purpose 

 intended. 



Should be on every rubber man's desk — Crude Rubber and 

 Compounding Ingredients; Rubber Country of the .Amazon: 

 Rubber Trade Directorv of the World. 



A FEW MORE FIGURES ON OVERSIZED TIRES. 



In our last two issues we published articles setting forth 

 the advantages of oversized solid rubber tire equipment on 

 motor trucks and gave some figures which demonstrated the 

 unwisdom of trying to economize by the adoption of smaller 

 and cheaper tires. As much or more has been done in the 

 collection of similar data for pneumatic tires and we present 

 herewith some figures supplied us by a prominent rubber 

 company. 



IT has been shown time and again that overspceding is one of 

 the worst enemies of the rubber tire, because of the con- 

 tinued distortion to which the rubber is subjected. The rubber 

 compound does not have time to recover from the shock before 

 it hits the road again, and often the distortion is permanent. 

 F.qually as important as the question of speed is the proper size 

 of tire for the load it is called upon to carry. It stands to 

 reason that for a given weight of car the larger-sized tire will 

 stand the greater amount of wear. But the percentage increase 

 (if the life of the tire far exceeds the increase of cost as well as 

 that of the amount of rubber. In short, oversized tires are 

 proven beyond any doubt to be a great economy. 



Tlie ligures in the following table are taken from five differ- 

 ent pleasure cars before and after equipping the wheels with the 

 larger tires. In each case both the front and the rear wheels 

 were of the same size, and not only was the capacity increased 

 as indicated, but the life of each set of tires was lengthened to 

 more than compensate for the extra cost. 



Tire size. Capacity. Oversize. Capacity. 



30x3 1400 lbs. 31x3^4 1700 lbs. 



32x3/2 1800 " 33x4 2900 " 



34x4 3000 " 35x4^ 3700 " 



36x4'A 3800 " 37x5 4400 " 



36x5 4300 " 37x5^ 5100 " 



Here it is seen that the larger equipment resulted in an in- 

 crease in the carrying capacity of the car of nearly 25 per cent. 



.-\gain, consider the standard car equipments. It is regrettable, 

 but none the less a fact, that some car manufacturers are in- 

 clined to place tires of too small size on their cars when they 

 are sent out froin the factory. The table below presents data 

 taken from four .American-made pleasure cars noted for their 

 pcior tire service, the names of the cars in question being desig- 

 nated by letters. The third column gives the capacities with the 

 tire equipment as ordinarily supplied, while the last column indi- 

 cates the capacity which would be realized by the adoption of 

 oversized tires on the same rims. 

 Car. Tire size. Car weight. Tire capacity. Oversize. 



A 32x3^ 2333 lbs. 1800 lbs. 2900 lbs. 



B 36.x4 3450 " 3200 " 3900 " 



C 36x4'^ 4100 " 3800 " 4400 " 



D 37.xS 4<575 " 4400 " 5200 " 



These figures require no further proof of the advantages 

 gained by the adoption of tires of adequate size. 



It should be remembered, however, that an oversized tire does 

 not take care of abuse and ovcrspeeding. With pneumatic tires 

 it is found that a car which averages 20 miles per hour and 

 never exceeds 30, will realize fair service even with undersized 

 tires. Such a car often runs 4000 miles on one set of tires, but 

 by running within the above speed limits on oversized tires the 

 same car should give at least 5000 miles of service. In excep- 

 tional cases, a set of oversized tires has been known to give a 

 mileage almost double that of the old equipment. 



THE PASSING OF THE STEEL TIHE. 



.All motor vehicle? in Germany must in future be equippel 

 with rubber tires, and France and England are expected to fol- 

 low with similar legislation. This will greatly increase the de- 

 mand for rubber tires, as many, especially of the commercial 

 motor vehicles, are still running on wood-block, spring and 

 other tires, which are highly detrimental to road surfaces. 



