ingenuity; that the realization of the latter would be of utility; that the complete design is not more than a theoretic possibility; and that the mill portion of it might be constructed at reasonable expense.
Babbage was distinguished for his skill in solving ciphers. He wrote a paper "On the properties of letters occurring in various languages" and it appears that these researches gave the keys which he used. In 1851 he communicated to the Trinity House a note respecting occulting lights in lighthouses. His idea of making each lighthouse publish its own name was forthwith adopted by the English and American Governments. The application of the same idea to solar light led to the invention of the heliograph, first brought into practice by the Russians at Sebastopool and which figured so prominently in the siege of Ladysmith.
Babbage's last book, published in 1864, was a kind of autobiography entitled Passages from the Life of a Philosopher. Like many of his works it was brilliant in conception but incomplete in execution. In his later years he came before the public as the implacable foe of organ grinders. He estimated that onefourth of his entire working hours had been wasted through audible nuisances to which his highly strung nerves rendered him peculiarly sensitive.
Charles Babbage died on October 18, 1871 in the 80th year of his age. To the public he was known as an eccentric and irritable person, as a crank on the subject of calculating machines. But his books show true nobility of nature; his engines exhibit marvelous mechanical ingenuity. He sowed many valuable seeds which less able but more thrifty minds turned to advantage. As a reformer he accomplished much for exact science, especially in the foundation of the Astronomical Society, the British Association, and the Statistical Society. The money expended by the Government on his machine was fully repaid, according to Lord Rosse, by the improvement in mechanical tools which he made incidentally in his designs. The main defect in his character was a want of persistence and an imperfect adjustment of his aims to what was practicable.
