METAL WORKING MACHINERY. 



BY EDWARD H. SANBORN. 



[Edward H. Sanborn, statistician; has liad chargo of important work in the United 

 States censuses of 1890 and 19UI), most of it being in connection with the manufac- 

 tures division of the bureau ; he was and is an expert in the iron and steel industry, 

 and in the last census was in charge of the investigation into the use of power by 

 manufactories.] 



Wliile the cost of some machine tools is higher now than 

 it was five or ten years ago, the machine of to-day is the more 

 economical because of its greater efficienc}^ The manufac- 

 turer who makes nothing but lathes, and manufactures 500 

 or 1,000 of them in a year, is able, as a rule, to build them 

 better and more cheaply than the maker who builds only a 

 few in a long list of other tools. Concentration on the details 

 of a single kind of machine or tool has been productive of 

 marked progress m construction, and has led to the gradual 

 evolution of new and advanced types. 



Specialization in the manufacture of machine tools has 

 followed closely the differentiation of processes in other lines 

 of industry, and thus there has been created a multitude of 

 special machines, each designed to perform some single and 

 often very simple operation. The bicycle industry furnishes 

 a striking illustration of the readiness with which the machine 

 tool builders met the demand for special tools to produce the 

 various parts required in the construction of a bicycle. The 

 advent of the chainless wheel called for a machine which 

 would cut small bevel gears accurately, rapidly, and economi- 

 cally, and such machines were quickly forthcoming. This, 

 indeed, is a characteristic tendency of the machine tool indus- 

 try — the effort to create new types of tools which will do more 

 and at less cost than can be done by any of the ordinary 

 appliances at the command of the machinist. 



Recent progress in machine tools and machine shop 

 practice has been marked by the following significant features : 



283 



