236 Mr. Babbage's Calculating Engines. 



tion of simpler mechanical means for executing the elementary 

 operations of that Engine, now acquired far greater importance 

 than it had hitherto possessed. 



In the Engine for calculating by differences, such simplifications 

 affected only about a hundred and twenty similar parts, while 

 in the new, or Analytical Engine, they might affect several thou- 

 sand. The Difference Engine might be constructed with more 

 or less advantage, by employing various mechanical modes for 

 the operation of addition. The Analytical Engine could not 

 exist without inventing for it amethod of mechanical addition pos- 

 sessed of the utmost simplicity. In fact it was not until upwards 

 of twenty different modes for performing the operation of addition 

 had been designed and drawn, that the necessary degree of simpli- 

 city required for the Analytical Engine was ultimately attained. 



These new views acquired great additional importance from 

 their bearings upon the Difference Engine already partly exe- 

 cuted for the Government ; for if such simplifications should be 

 discovered, it might happen that the Analytical Engine would 

 execute with greater rapidity the calculations for which the Dif- 

 ference Engine was intended; or that the Difference Engine 

 would itself be superseded by a far simpler mode of construction. 



Though these views might, perhaps, at that period,have appear- 

 ed visionary, they have subsequently been completely realized. 



To have allowed the construction of the Difference Engine to 

 be resumed while these new views were withheld from the Go- 

 vernment, would have been improper ; yet the state of uncer- 

 tainty in which those views were then necessarily involved, ren- 

 dered any written communication respecting their probable bear- 

 ing on that engine a matter of very great difficulty. It therefore 

 appeared to Mr. Babbage that the most straightforward course 

 was to ask for an interview with the head of the Government, 

 and to communicate to him the exact state of the case. Various 

 circumstances occurred to delay, and ultimately to prevent that 

 interview. 



From the year 1833 to the close of 1842, Mr. Babbage repeat- 

 edly applied to the Government for its decision upon the subject. 

 These applications were unavailing. Years of delay and anxiety 

 followed each other, impairing those energies which were now 

 directed to the invention of the Analytical Engine. This state 

 of uncertainty had many injurious effects. It prevented Mr. 

 Babbage from entering into any engagement with other Govern- 

 ments respecting the Analytical Engine, by which he might 

 have been enabled to employ a greater number of assistants, and 

 thus to have applied his faculties only to the highest depart- 

 ments of the subject, instead of exhausting them on inferior ob- 

 jects, that might have been executed with less fatigue by other 



