© Committee on Public Information 



"doping" the wings op airplanes 



In the parlance of the day, "dope" suggests sluggishness and lowered vitality, but in the 

 manufacture of airplanes it means speed. Dope is a liquid compound with which the linen 

 covering the wings of a flying machine is treated to shrink the fabric and make it taut over 

 the framework, thus reducing its resistance to the air. 



out in places of extra weight, and made 

 ready as unit pieces. This is a task 

 for the finest woodworkers or cabinet- 

 makers. 



Then comes the laying of the keel, as 

 we may call it, the putting down of the 

 basic wing-spars, simple enough in ap- 

 pearance, but so carefully selected that 

 their final cost is estimated at from $30 

 to $50 each. Next is the fitting in of the 

 ribs, or cross-pieces, as many as 30 to a 

 wing, and themselves coming to a final 

 cost of about $9 each. Obviously, again, 

 only an expert in woodworking can se- 

 cure the exact setting required. 



When finally all the ribs are firmly 

 joined, the wing remains but a skeleton 

 without the necessary covering to make 

 it solid. Linen is the one perfect ma- 

 terial known for this purpose, because it 

 is light, strong, and will not rip, as cotton 

 does, when pierced with bullets. But the 

 supply of linen also ran short under the 

 tremendous war demands, especially with 

 that from Belgium and northern France 



cut off, and it was only when England 

 mobilized all her strength that the world's 

 best supply center in Ireland was able to 

 rise to the demand. A little idea of how 

 much is needed for the American pro- 

 gram alone is found in the fact that each 

 of our thousands of machines requires 

 201 square yards. 



A MAXIMUM OP STRENGTH AND 

 TIGHTNESS 



Once secured, the linen must be cut to 

 size, reinforced in places of stress, and 

 then sewed in back and forth over each 

 rib to make it absolutely tight and able to 

 withstand a 150-mile wind pressure. This 

 work is mostly done by women working 

 in pairs, pushing a long 3-inch needle 

 from one side to the other. Xo one has 

 ever estimated the number of stitches 

 necessary for a single plane. 



When the sewing is completed, our 

 wing is in a semi-finished state. It rep- 

 resents the maximum of strength and 

 lightness which human ingenuity has as 



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