168 CHARLES BABBAGE. 



seum at Somerset House. In 1862 it was exliibited at the Great Indus- 

 trial Exhibition, since which time it has been stored at the South Ken- 

 sington Museum. The finished portion of the engine showed itself 

 capable of computing any table whose third difference is constant and 

 less than 1,000; while at the same time it showed the position in the 

 table of each tabular number. In Mr. Babbage's own words: 



"1st. The portion of the machine exhibited can calculate any table 

 whose third difference is constant and less than 10. 



"2d. It can show how much more rapidly astronomical tables can be 

 calculated in any engine in which there is no constant difference. 



"3d. It can be employed to illustrate those singular laws which might 

 continue to be produced through ages, and yet after an enormous inter- 

 val of time change into other different laws; each again to exist for 

 ages, and then to be superseded by new laws." 



It will be borne in mind that- all work upon difference engine ISTo. 1 was 

 stopped in the early part of the year 1833. At the general meeting of 

 the Royal Academy at Brussels in May, 1835, a letter received from Mr. 

 Babbage was read announcing that he had been engaged for six months 

 in making drawings of a new calculating machine of far greater power. 

 "I am myself astonished," he wrote, "at the power I have been enabled 

 to give to this machine : a year ago I should not have believed this result 

 possible. The machine is intended to contain a hundred variables, each 

 consisting of twenty-five figures; it will reduce to tables almost all 

 equations of finite differences; it will calculate a thousand values (of 6.(7. 



al) c dhj the formula jp= -i- j print them, and reduce them to zero, 



and will then ring a bell to give notice that a new set of constants 

 must be inserted." "When there exists," he continues, "a relation 

 between any number of successive co-efficients of a series, provided it 

 can be expressed, the machine will calculate them and make their 

 terms known in succession ; and it may afterward be disposed so as to 

 find the value of the series for all the values of the variable." 



This was the first announcement to the scientific world of a machine, 

 capable of executing not merely arithmetical calculations, but even those 

 of analysis when the laws are known. It was, in fact, the analytical 

 engine, never destined to be com}3leted by its inventor in actual fact, 

 but so perfect in its drawings, so clear in its descriptions, so certain in 

 its sequences, and so logical in aU its principles, that, to the minds of 

 men capable of comprehending the details, it became as certainly the 

 realization of a gigantic idea as if it had been doing its work in their 

 presence. If it be asked, how such a machine could of itself, without 

 recourse to thought, assume the successive dispositions necessary, Mr. 

 Babbage answers that Jacquard solved the problem when he invented 

 his loom. 



In the manufacture of brocade there are two species of threads, the 



