OF ARTS AND SCIENCES : JUNE 4, 1872. 457 



the wonderful powers of this machine. - It bore about the same rela- 

 tion to the other that algebra does to arithmetic, and, instead of merely 

 computing arithmetical tables, it was designed to deal with all forms of 

 analytical operations. Suppose we have any formula whatsoever from 

 which we wish to compute a series of numerical values. Two sets of 

 cards, like those of a Jacquard loom, are furnished the engine, the first 

 to direct the nature of the operations to be performed, and the second 

 to show which variables are to be acted upon. The numerical values 

 of the constants being placed on the wheels, it would compute and 

 print the results of the formula. If, during the operation, it wanted 

 some other quantity, as the logarithm of a given number, it would ring 

 a bell, and then stop. The attendant would find out what was wanted, 

 and, procuring the logarithmic card, would place it in the machine. The 

 latter would first see if it was correct, and, if not, would ring a louder 

 bell and again stop. It would express every number it used to fifty 

 places of figures, and would multiply two such numbers, giving a hun- 

 dred places in the product, in about a minute. The complication of 

 this instrument was such that it was impossible to represent it by or- 

 dinary drawings. Babbage, therefore, used a system of mechanical 

 notation which he had devised, and without which he claimed that it 

 could not have existed even upon paper. 



In 1833, a portion of the Difference Engine was put together 

 and worked admirably, computing tables with two or three orders of 

 differences to sixteen places ; but, unfortunately, the new invention 

 seemed to supersede it, and finally, in 1842, the government, after 

 spending £17,000 on the project, refused to give any further aid. 

 Babbage now devoted his whole attention to the engrossing subject of 

 the Analytical Engine, and succeeded so far that, with sufficient 

 means, there seems to be little doubt that he would have attained all 

 that he claimed. 



His health suffered severely from the intense mental strain to which 

 he was subjected in designing his engines, and, in consequence, he 

 travelled a great deal both in England and on the Continent. As he 

 seems to have availed himself of every opportunity to inspect in per- 

 son any novelty he met with, we find him in many strange positions, 

 and often narrowly escaping serious accidents. Thus, as a boy he was 

 nearly drowned while testing a swimming-machine he had constructed. 

 Again, in the Thames Tunnel, in company with Brunei, the water 

 breaks in, and, but for the presence of mind of the latter, both would 



vol. viii. 58 



