INTER-DEPENDENCE AND INTEGRATION. 409 



measure dependent on the genesis of many other products, 

 but, conversely, many other products are profoundly influ 

 enced by the genesis of each. The many affect the one and 

 one affects the many. 



A striking instance is afforded by the caoutchouc manu 

 facture. Originally called india-rubber in recognition of its 

 place of origin and its solitary use for rubbing out pencil- 

 marks, this substance has in the course of sixty or seventy 

 years not only yielded us numerous articles of personal and 

 domestic convenience, but has also improved various indus 

 tries. It is replacing leather for machine-belting, for fire- 

 engine hose, for the tubing used in various businesses. 

 It is used for buffers, valves for engines and pumps, washers 

 for pipe- joints, piston-packing, squeezing-cylinders, and now 

 most conspicuously for the wheels of carriages and cycles. 

 So that by its radiating influences the india-rubber manufac 

 ture has modified many other manufactures. 



Still more striking, and far more important, have been the 

 radiating influences of the Bessemer-steel manufacture. A 

 material, the expensiveness of which, until 1850, was such as 

 to limit its use mainly to cutting instruments, is now em 

 ployed wholesale for things of large size armoured vessels 

 of war, great fast steamers and ships generally, with their 

 boilers, propellers, shafts, chain-cables, anchors, &c. Steel 

 wire has come into extensive use for traction-ropes, hawsers, 

 and vast suspension-bridges; while viaducts, larger than 

 were before practicable, are now framed of steel. In 

 houses, steel-girders, beams, floor-joists are replacing those 

 of wood ; and in Xew York enormous steel-frameworks hold 

 together their vast, many-storied buildings. In all kinds of 

 machinery steel is replacing iron in cog-wheels, axles, 

 cranks, framings. Thin sheet-steel is being stamped into 

 bowls, trays, cans, saucepans, covers, etc., and from sheet- 

 steel, tinned plates are now made to an immense extent. In 

 1892, in the United States alone, more than 200,000 tons of 

 steel nails were manufactured. But above all there are the 



