June 1. 1916.] 



THE INDIA RUBBER WORLD 



Rubber in the Construction of Aeroplanes. 



THE balloon has not received as much attention in America 

 as in Europe. Americans have never believed that it 

 would become really practical, and heavier-than-air ma- 

 chines have possessed more attraction for our inventors. The 

 problem of mechanical flight has given birth to many chimerical 

 plans and projects, but the fact remains that, although most of 

 the earlier theoretical literature on the subject came from 

 France, practical results with machines heavier than air were 

 first obtained by Americans. 



As far back as 1894, Hiram Maxim, an .American residing in 

 England, constructed a flying machine, provided with a steam en- 

 gine, which showed flying capability but lacked stability. Pro- 

 fessor Langley, secretary of the Smithsonian Institution at 

 Washington, built several working models of flying machines 

 propelled by steam engines, of which two, in 1890, made aerial 

 flights of about a mile. Then followed, also in .\merica, the re- 

 markable "gliding" experiments of Lilienthal, Chanute, Herring 

 and finally of the Wright lirothcrs who, as far back as 1902, had 

 completed gliders 

 possessing most 

 of the refine- 

 ments of modern 

 aeroplanes, minus 

 the motor. Since 

 Wilbur Wr i g h t 

 made his histori- 

 cal flight in 1908 

 — the first me- 

 chanical flight 

 worthy of the 

 name — gigantic 

 strides have been 

 made towards 

 perfec t i o n in 

 navigating the 

 atmosphere with 

 machines heavier 

 than air, and 

 thousands of suc- 

 cessful aeroplanes of many types have been produced. The 

 flying machine has proved its value both as a vehicle 

 of sport and as an instrument of war. The new industry 

 has been growing rapidly all over the world. Forty American 

 aeroplane factories are now working full force on foreign gov- 

 ernment orders for flying machines, and consequently it seems 

 quite worth while to go somewhat into details concerning this in- 

 dustry and the extent to which rul)ber is used in the construc- 

 tion of aeroplanes. 



AEROPLANE CONSTRUCTION. 

 There are four important ways in which rubber is used in the 

 construction and use of aeroplanes : First, in the pneumatic 

 tires with which the wheels are equipped; second, in the rubber- 

 ized fabric for covering the wings and other surfaces; third, 

 m the construction of shock absorbers, and fourth, in the equip- 

 ment of the aviator and passengers. 



All aeroplanes — some water-aeroplanes excepted — are equipped 

 with wire wheels similar to motorcycle wheels and provided with 

 pneumatic tires which are either cemented, glued or attached 

 with lugs to the rims of the wheels. The Dunlop type of tire 

 is most favored for aeroplane service on account of the facilities 

 it offers for light construction. The size of wheels and tires 

 varies with the type of machine. Aeroplane tires must be at- 

 tached very tightly to their rims, for the slipping off of a tire is 

 even more dangerous to an aviator bringing his machine to earth 



Aeroplane Flown Duri 



than it is to an autonioliilist taking a corner on the road. Aero- 

 plane tires must have great resiliency and strength of fabric to 

 withstand the terrific shock when an aeroplane alights on rough, 

 uneven ground. A blow-out at such a moment might prove fatal. 

 The plain tread is perhaps most used, although aeroplane tires 

 are also made on the non-skid plan. The tire and the rims of 

 the wheels of aeroplanes should be constructed so as to make 

 rim-cuts impossible even when the landing shock flattens out the 

 tires. 



AEROPLANE FABRICS. 

 Fabrics play an important role in aeroplane construction. As 

 long as the cloth covering the sustaining planes of a flying 

 machine stays taut in all kinds of weather, little attention is 

 paid to it, but when it alternately shrinks and stretches, when 

 it shows itself as sensitive as a hygrometer to the presence or 

 absence of atmospheric moisture, aviators and aeroplane con- 

 structors soon realize the importance of aeroplane cloth. The 

 quality of the cloth affects the efficiency and even the safety of 



a flying machine. 

 Aeroplane cloth 

 must be mois- 

 ture-proof, heat- 

 proof and cold- 

 proof, and it 

 must not oxidize 

 in the sun or be- 

 come affected by 

 gasolene or en- 

 gine oil. 



The following 

 fabrics are used 

 in the construc- 

 t i o n of a e r o- 

 planes; Cotton 

 canvas, either 

 u n b 1 e a ched or 

 colored in yellow, 

 and weighing 

 from 145 to 150 

 grams (4.90 to 5.07 ounces) per square meter (10.764 square 

 feet), is used single-fold for covering the sustaining sur- 

 faces of flying machines. The tensile strength of this 

 canvas is from 2,200 to 2,800 pounds per running yard 

 and its thickness about 0.18 millimeter (0.007 inch). 

 Some constructors use cotton canvas weighing from 180 to 2(X) 

 grams (6.34 ounces to 7.05 ounces) per square meter (10.764 

 square feet), having a tensile strength of about 2.600 pounds to 

 the running yard and a thickness of about 0.18 millimeter (0.007 

 inch). Flax fabrics or linen are most used. Linen fabrics 

 weigh about 145 grams (4.90 ounces) to the square meter (10.764 

 square feet) and their tensile strength is in the neighborhood 

 of 3,600 pounds to the running yard or 18.80 pounds to the square 

 millimeter (0.00155 square inch), while their thickness is around 

 0.20 millimeter (0.0078 inch). Silk fabrics, though stronger than 

 others for their weight, are not used in the construction of aero- 

 planes on account of their excessive cost, 



French constructors use quantities of ramie fabric. This 

 weighs 120 grams (4 ounces) per square meter (10.764 square 

 feet), its tensile strength is 2,120 pounds per running yard, or 

 13.64 pounds per square millimeter (0.00155 square inch), and its 

 thickness 0.17 millimeter (0.0066 inch). Ramie fabrics are very- 

 tough «nd hard to tear. 



MAKING THE FABRIC MOISTURE PROOF. 

 Rubberized fabrics were used almost exclusively for coverinjf 



THE New York Preparedness Parade, May 13, 1916. 



