p20 
afterwards read in a public fitting of the 
Inftitute. 
On the 22d of June the Inftitute pre- 
fented to the two councils the original 
ftandards of the metre and kilogramme 
of platina, which were placed in,the mag- 
nificent depot of the national archives in the 
national palace, formerly the Tuilleries. 
On the 17th of November the confuls 
propofed a law to declare that the metre 
and the kilogramme -are the definitive 
fiandards of France, and to*caufe a medal 
to be ftruck in commemoration of this 
grand undertaking. On one fide is to be 
reprefented the Republic holding the metre” 
and the kilogramme, with this inf{cription, 
«¢ Toali ages and all nations ;*’ and onthe 
exergue, ** French Republic, year 7.” 
‘The figure will be on a plinth of five cen- 
timetres. ‘ 
The reverfe will exhibit the globe of 
the earth, a pair of compaffes extended” 
from the equator to the pole, the conftel- 
lation of the lefler bear, and the following 
infcription — ‘* Unity of meafures, ten 
millionth part of a quarter of the me- 
ridian.”” 
By reducing thefe meafures to the tem- 
perature of ten degrees, which is the mean 
degree of the heat at Paris, and that in 
the caverns below the obfervatory, I find 
the 45th degree to be 57012 toifes, inftead 
of 57031 which I had adopted in my 
aftronomy. ‘This is 19 toifes lefs ; the 
mean radius of the earth 3268159 toifes, 
lefs by 1323 tcifes than my Table, which 
hitherto has. ferved as a rule in books of 
natural philofophy. This, without doubt, 
is very little in regard to the extent of the 
earth: we are therefore preity well ac- 
quainted with its fizé, but we are not fuffici- 
ently acquainted with its irregularities ; 
and this, at any rate, is one important 
refult from this new labour. 
This year has furnithed us with three 
new comets. On the 6th of December, 
1798, C. Bouvard difcovered, at the ob- 
fervatory, 2 {mall one in the conftellation 
of Hercules ; it was feen only during fix 
days, and difappeared on the rrth of De- 
cember in Aquarius, but C. Burckhardt 
calculated its orbit with all poffible pre- 
cifion. 
Mechair, to whom we are already in- 
debted. for the difcovery of fo many co- 
mets, found one on the morning of the 7th 
of Auguft, which is the goth according 
to the general catalogue in the third edi- 
tion of my Aftronomy. It was very {mall 
and without any tail, but exceedingly 
eleay ; it was above the Lynx, in the con- 
Hi ftiry of Afirenomy, for 1799, by Lalande. 
' ¢he meridian and the metre, which was 
[ Aprils, 
ftellation which Hell formed in 1790, un- 
der thename of the Grand Telefcope of 
Herfchel. At three o’clock in the morn- 
ing it had 107° 47’ of right afcenfion, and 
43° 54' of north declination. It was 
among the ftars which Lefrancais obferved 
on the 9th of March, 1794, fo that very 
exact pofitions were obtained. 
Mechain and Burckhardt each calcu- 
lated the orbit with that ardour and readi- 
nefs which are natural to thefe able aftro- 
nomers: C. Meffier followed its progrefs, 
according to his ufual cuftom, with inde~ 
-fatigable affiduity, for more than two 
months, till the 25th of O&tober, when it 
difappeared on the eaftern knee of Ophi- 
uchus. Durjng this long appearance our 
collection of 50,000 fiars has often fur- 
nifhed important points for the reduction 
of thefe obfervations. On the laft day it 
was near a ftar of the fixth magnitude, 
the pofition of which I have given in the — 
Connoiffance des Tems for the year 10. All 
the obfervations of C. Mechain and Mef- 
fier will be publifhed in detail: fome of 
them have a wonderful degree of perfec- 
tion, becaufe they were made by means of 
an excellent meridian telefcope, by Le- 
francais and Burckhardt. | 
This day alfo, December 26, 1799, at 
half after five in the morning, C. Mechain 
difcovered a new comet in Ophiuchus, 
which will be the gift. It had about 
"269° of right afcenfion and 5° of northern 
declination, It appeared tothe naked eye 
as a ftar of sth and 6th magnitude in the 
telefcope. Its nucleus was exceedingly 
luminous, and almoft bounded: it hada 
very narrow-tail, of a pretty intenfe light, 
and about 7° in length. It advanced to- 
wards the fouth fo rapidly that it was 
apprehended it could not long be ob- 
ferved, unlefs it fhould appear in the welt, 
after having traverfed a part of the fouth- 
ern hemifphere. ; 
As the moft defective part of aftronomy 
at prefent is what relates to comets, 
mult recommend them to all our corre- 
{fpondents. The Bureau des Longitudes 
has fent a night-telefcope to C. Flau- 
gergues at Viviers, who has promifed to 
make ufe of it. 
Mougin, in the department of Doubs, 
has promifed the fame thing ; but, being 
a prieft, he'was obliged to quit La Grand 
>Combe-des-Bois, where he was curé, and 
where, fince 1766, he had made many ob- 
fervations and calculations, and had been 
banifhed to a hollow valley where he could 
no longer have a proper view of the hea- 
vens. The government has thought pro- 
per to fuffer him to refume his ihe 
an 
