History of Astronomy for the Year 1805. 243 
according to Herschel’s memoir. He finds 3°5” for Piazzi 
for distance ; diameter 587 leagues: Olbers, 4:5”; diameter 
_760 leagues: Harding, 31”; diameter 515 leagues. 
In the Bibhothéque Britannique of the month of August 
there is an ephemeris of the three planets up to the month 
of May 1806. 
The astronomical medal founded by Lalande, which is 
adjudged every year towards the spring equinox, has been 
decreed by the Institute to M. Harding for the discovery of 
his planet. 
The prize which M. Bode had been charged to give for the 
best memoir on astronomy, has been raised to 600 francs. 
M. Laplace read at the Institute a memoir upon the ca- 
pillary tubes, in which he gives the analytical calculation of 
their attraction perfectly conformable to experiments. There 
is an extract of it in the Journal de Physique for January 
1806. I read one myself upon levelling = where I explained 
the table of the level made use of in going from the north 
to the south, and that which must be employed when we 
level from the east to the west, on account of the figure of 
the earth ; a consideration which has hitherto escaped all the 
authors who have written of levelling. 
- 
The fifth volume of the Institute, which appeared on the 
14th of January, contains fourteen memoirs on astronomy. 
I have there given researches upon the motions of Mercury, 
Mars, and Venus; some calculations of occultations of the 
stars, and a description of the zodiac of Strasbourg. M. De~ 
lambre there treats of the stereographic projection, and of the 
astrolabe of Senezius, which M. Gail had stated to the class. 
There is also a memoir of M. Messier upon the transit of 
Mercury; observations of M. Ferrers in America; on the 
oscillation of Mars, by M. Duc la Chapelle; and a notice 
of the grand tables of logarithms which M. de Prony has 
caused to be calculated ; and some remarks upon the history 
of the trigonometric tables. M. Cassini there gives the de- 
scription of his compass. 
The London Transactions for 1803 contain a memoir of 
M. Herschel uppn the transit of Mercury, where he has not 
Q2 perceived 
