L. F. MENABREA ON BABBAGE’S ANALYTICAL ENGINE. 667 
chinery. By Charles Babbage, Esq-—Philosophical Transac- 
tions. London, 1826. 
7. On Errors common to many Tables of Logarithms. By 
Charles Babbage, Esq.—Memoirs of the Astronomical Society, 
London, 1827. 
8. Report of the Committee appointed by the Council of the 
Royal Society to consider the subject referred to in a communi- 
cation received by them from the Treasury respecting Mr. Bab- 
bage’s Calculating Engine, and to report thereon. London, 
1829. 
9. Economy of Manufactures, chap. xx. 8vo. London, 1832. 
10. Article on Babbage’s Calculating Engine.—Edinburgh 
Review, July 1834. No. 120. vol. lix. 
The present state of the Difference Engine, which has always 
been the property of Government, is as follows :—The drawings 
are nearly finished, and the mechanical notation of the whole, 
recording every motion of which it is susceptible, is completed. 
A part of that Engine, comprising sixteen figures, arranged in 
three orders of differences, has been put together, and has 
frequently been used during the last eight years. It performs 
its work with absolute precision. This portion of the Difference 
Engine, together with all the drawings, are at present deposited 
in the Museum of King’s College, London. 
Of the ANALYTICAL Eneine, which forms the principal ob- 
ject of the present memoir, we are not aware that any notice has 
hitherto appeared, except a Letter from the Inventor to M. 
Quetelet, Secretary to the Royal Academy of Sciences at Brus- 
sels, by whom it was communicated to that body. We subjoin a 
translation of this Letter, which was itself a translation of the 
original, and was not intended for publication by its author. 
Royal Academy of Sciences at Brussels. General Meeting of the 
7th and 8th of May, 1835. 
“A Letter from Mr. Babbage announces that he has for six 
months been engaged in making the drawings of a new calcu- 
lating machine of far greater power than the first. 
“*T am myself astonished,’ says Mr. Babbage, ‘at the power I 
have been enabled to give to this machine; a year ago I should 
not have believed this result possible. This machine is intended 
to contain a hundred variables (or numbers susceptible of chan- 
