which had appeared in but faint perspective in 1834, as likely to lead to important consequences, had, by this time, assumed a form and distinctness which fully justified the anticipations then made. By patient inquiry, aided by extensive drawings and notations, the projected Analytical Engine had acquired such powers, that it became necessary, for its further advancement, to simplify the elements of which it was composed. In the progress of this inquiry, Mr. Babbage had gradully arrived at simpler mechanical modes of performing those arithmetical operations on which the action of the Difference Engine depended; and he felt it necessary to communicate these new circumstances, as well as their consequences, to the Chancellor of the Exchequer.
On the 20th of January, 1836, Mr. Babbage wrote, in answer to the communication from the Chancellor of the Exchequer, that he did not, on re-examining the statement addressed to the Duke of Wellington, perceive that it contained any application to take up the new or Analytical Engine; and he accompanied this reply by a statement relative to the progress of the Analytical Engine, and its bearing upon the Difference Engine belonging to the Government/ The former, it was said,
"Is not only capable of accomplishing all those other complicated calculations which I had intended, but it also performs all calculations which were peculiar to the Difference Engine, both in less time, and to a greater extent: in fact, it completely supersedes the Difference Engine."
The Reply then referred to the statement laid before the Duke of Wellington in July, 1834, in which it was said,
"That all the elements of the Analytical were essentially different from those of the Difference Engine;"
and that the mechanical simplicity to which its elements had now been reduced was such that it would probably cost more
