1803.] 
the invention cannot, with propriety be 
refufed him. 
3. He has brought to perfeétion the 
mechanifm of the machine for laminating 
or plating metals—fo that the fame move- 
ment which carries along the inferior 
cylinder, carries, likewife, the fupe- 
rior cylinder. He has eftablifhed fure me- 
thods to regulate the parallelifm and the 
deviation of the cylinders. 
4. Important impovements have been 
made in the machine for cutting the pieces 
to be ftamped, which are entirely owing 
to his genius and ability. 
5» There is fcarcely any piece of the 
dye or ftamp in which he has not made 
ufeful improvements, as for inftance, fub- 
ftituting the cylindrical {crew for the co- 
nical f{crew, inventing the melting-box 
(Soite coulante), furnifhing accurate and 
folid methods of adapting the fuperior 
coin to it, and laftly, he has invented and 
added to it the mechanical hand which 
brings under the dye or ftamp, by the 
fame movement which is impreffed upon 
it, the piece to be itruck, and removes 
the one that had been ftruck jult before ; 
an operation which was always hitherto 
performed by the hand, not without dan- 
ger to the performer, or at leaft, without 
affright for the fpectators. In a word, 
it appears from the ftatement of the com- 
miflaries, that the machine of Citizen 
Droz, when it is properly managed, pro- 
duces about fixty ftrokes a minute, and 
that it is, in every refpeét, worthy of the 
high reputation which it enjoys. 
From all thefe details, the Commiffaries 
conclude that Citizen Droz merits a very 
honourable mention among thofe who 
have contributed the molt to meliorate 
the money-making fyftem. The Clafs has 
adopted this report, as likewile, the con- 
clufions deduced from it. ye 
- SE ara 
BOARD. OF LONGITUDE OF 
PARIS. 
‘EXTRACT of @ REPORT made to the Bu- 
REAU des LONGITUDES (BOARD of 
LONGITUDE,) of PARIS, om the LuU- 
NaR TABLES, fent tothe CONCOURS, 
opened in the MONTH of MESSIDOR, 
YEAR 8. 
HE public are no ftrangers to the inte- 
re(t with which the National Inftitute 
received, two years ago, the Memoirs of the 
aftronomers Biirg and Bouvart, on fome of 
the elements of the Lunar Tables. ‘Struck - 
with the importance and immenfity of 
their labour, the Clafs of Mathematical 
and Phyfical Sciences, influenced that day 
Proceedings of Learned Societies. 
251 
by the perfon who of all its members 
could the beft infure the ec/at and the fuce_ 
cefs of its deliberations, agreed'to double 
the prize which it was to beftow. In do- 
ing much more than had been required of 
them, the candidates had given rife to 
a gueftion more difficult than that 
which they had refolved. One and the 
fame mean motion could not compleatly 
account for the epochs which they had 
eftablifhed, for the commencement, the 
end, and the middle, of the 18th century. 
This irregularity, fo alarming for the 
future precifion of the tables, could only 
be explained, by fuppofing, either that 
the inequalities already included in the 
tables were not fufficiently well known, 
or that fomz equations were yet wanting, 
which had hitherto efcaped the refearches 
of all the geometers. © 
The difcouraging labour which thefe 
new confiderations demanded, gave no 
reafon to expect a folution fo prompt as 
was requifite for the calls of aftronomy 
and of navigation. It feemed like mak- 
ing a fort of appeal to all aftronomers, in 
the hopes that fome individual might have, 
perhaps, amaffed, in a courfe of time, all 
the neceflary materials. The Bureau des 
Longitudes applied with confidence toa 
Government conftituted in fuch a manner 
as to feel the value of the {ciences, and the 
utility of their applications, better than 
any other that ever exifted. With its ap- 
probation, the Minifters of the Interior 
and of the Marine raifed, in equal por- 
tions, the fund of an extraordinary prize 
‘of 6000 francs, which they quickly pro. 
pofed to the emulation of the aftronomers 
of all countries. I’wenty months after 
this announcement, the Bureau des Longi- 
tudes received the new Tables, of which 
we fhall give fome account. 
In order to verify Tables conftruéted on 
the total amount of the good obfervations 
publifhed heretofore, other obfervations, 
equally good, but new, were found necef- 
fary. One hundred and fifty: were choten, 
as well from the regifters of the National 
-Obfervatory of Paris, as from the laft 
numbers publifhed by the Royal Aitrono. 
mer of England, and from a correfpon- 
dence maintained: with the Director of the 
Oblervatory of Gotha. Indeed, it was 
impoffible to find any that merited more 
confidence, either from the excellence of 
the inftruments, or from the acknowledged 
ficrit of the obfervers. 
We fhall paricularize, in a few words, 
the difficulties which the author of the Ta- 
bles had to furmount, and the precifion 
which he has been enabled to attain, 
ka ca 
