After the death of Babbage in 1871 what he had accomplished
on the Analytical Engine was transferred for safe-keeping
to the Museum at South Kensington. The British Association
appointed a committee to examine it; in 1878 they reported
that the part assembled was only a small portion of the mill
sufficient to show the methods of addition and subtraction;
that the drawings were complete in exhibiting every movement
essential to the design of the machine. They concluded that the
labors of Babbage, first on the Difference Engine, and after-
wards on theAnalytical Engine were a marvel of mechanical



CHARLES BABBAGE 83

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 reason-
able 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 id^a to solar light led to the inven-
tion of the heliograph, first brought into practice by the Russians
at Sebastopool and which figured so prominently in the siege of
Ladysmith.
