S74 Mi* Babbage Machmer^ for Cdkulaiing 
tween the formations which I observed in Hungary, and those 
which resemble them in different parts of our globe ; the collec- 
tions of the islands of Paros, Milo, Nipoligo, Patmos, Santorin, 
&c. have been for me a source of precious comparisons. The 
collections of different parts of Germany were still well adapted 
to arrest m}^ attention, and those which M. Freisleben has ga- 
thered in Mansfeld and Thuringia, and which form the founda- 
tion of the excellent work which he has published on these coun- 
tries, still presented a mass of details and of geological relations 
of the highest interest. Lastly, the geological maps of Saxony, 
which all the lovers of science are anxious to see published, and 
which M. Kuhn, professor of geology, had the kindness to sub- 
mit to my inspection, accompanying them with a multitude of 
details, which are still nowhere to be found, were to me a sub- 
ject of very instructive investigation. 
Art. XIV . — On Machinery for Calculating and Printing Ma^ 
thematical Tables By Charles Barrage, Esq. E. R. S. 
Lond. and Edin. &c. 
Among the brilliant inventions which have distinguished the 
present age, the machinery invented by Mr Babbage for perform- 
ing intellectual labour, is entitled to a prominent place. Low as 
that species of mental exertion undoubtedly is, when the mathe- 
matician performs the monotonous round of arithmetical calcula- 
tions, in which neither the power of combination nor of judgment 
is called into action ; yet we were not prepared to see even these 
humbler functions placed under the surveillance of wheels and 
pinions ; and hence the first intelligence of a calculating machine 
has been received with as much incredulity by the wise as by the 
vulgar. 
The object which Mr Babbage had in view in constructing 
this new machinery, was to produce printed copies of any msu 
thematical tables, without the possibility f an error existing in 
a single copy. This result he proposed to attain solely by ma- 
* This paper is drawn up from different private sources of information, but 
particularly, from Mr Babbage’s printed letter on the subject, addressed to Sir 
Humphry Davy, Bart. — En. 
