1822.] Mr. Babbage’s Letter to Sir H. Davy. 383 
with an achromatic telescope, four feet long, and magnifying 100 
times, it seemed like a star of the sixth magnitude, with three 
other spots much smaller, one of which was more brilliant than 
that first noticed. The largest was surrounded by a nebulous 
appearance, which could not be perceived about the smallest 
and the two others were similar to faint nebulz, increasing im 
intensity towards the middle, but without any defined luminous 
point. On the 29th, the large spot was as bright as before, two 
others were nearly invisible, and the small brilliant one had 
disappeared. 
XVIII. On the Difference in the Appearance of the Teeth and 
the Shape of the Skull in different Species of Seals. By Sir 
Everard Home, Bart. VPRS. 
This notice is accompanied by three plates, showing the great 
difference existing between the skulls and teeth of three seals - 
one from the South Seas, another from the Orkney Isles, and a 
third from New Georgia. Sir Everard conceives that the know- 
ledge they impart will be an advantage, when fossil remains of 
the seal shall be met with. 
The mean height of Six’s thermometer, in the year 1821, is 
stated in the Meteorological Journal kept at the Society’s 
apartments, to have been 51°8°; the mean height of the baro- 
meter 29°86 in.; and the quantity of rain for the year 23-567 
inches. 
— 
2. A Letter te Sir Humphry Davy, Bart. President of the 
Royal Society, &c. &c.on the Application of Machinery to the 
Purpose of Calculating and Printing Mathematical’ Tables, 
From Charles Babbage, Esq. MA. FRS. L. & E. Member of 
the Cambridge Philosophical Society, Secretary of the Astro- 
nomical Society of Lendon, and Correspondent of the Philo- 
mathic Scciety of Paris. London, 1822. 
We had occasion, a few months since, to notice a work, in 
which is detailed the progressive improvement and present high 
state of perfection and importance of the Steam-Engine, a 
~ machine which has been preductive of such stupendous effects 
in its application to the arts and manufactures. We have now 
to state the applications of an imvention in mechanics, which is 
calculated, extraordinary as it may appear, to produce as momen- 
tous consequences in science, by the substitution of its move- 
ments for intellectual labour, as those to which the steam-engine 
has given rise, in the arts of civilized society, by the abridgment 
of bodily toil. 
The high rank which Mr. Babbage sustains as a mathemati- 
cian must be well known to our readers, He commences the 
