1801.] Profeffor Bygge on the French Weights and Meafures. 201 
various Curiofities, and the colleGtions re- 
lative tothe arts and {ciences, with which 
the metropolis of the French republic 
abounds, have already been prefented to the 
Britifh public in an Englifh tranflation. 
A. fecond volume: has lately been pub- 
lifhed by the fame author, containing, 
among other matter, remarks on_ the 
French fyftem of weights and meafures, 
which we fhall give to our readers. 
Profeffor Bygge fhews himfelf confideta- 
bly averfe to this fyftem ; and perhaps the 
time is come in which this important plan 
may be examined with more impartiality 
in France, as the firft impreffions produced 
by this bold and ingenious undertaking are 
very confiderably worn off. 
Profeflor Bygge begins by fhewing the 
great inconvenience which was felt by the 
extreme variety of weights and meafures 
in common ufe in France, which differed 
not only in diftant provinces, but even in 
neighbouring towns; and he juftly praifes 
the wife intentions of the government, in 
reducing the whole to acommon ftandard. 
‘¢ The eafieft, fimpleft, and leaft expenfive 
method of accomplifhing this objeét,’” he 
obferves, ** would have been, doubtlefs, to 
have taken for the ftandard of length the 
French foot (pied de roi), the ufe of which 
was univerfal throughout France, and its 
relation with the meafures of other coun- 
tries moft accurately afcertained. In like 
manner, for admeafurement of weight, 
the poids de marc might have been rigidly 
adhered to, as it is much ufed throughout 
Europe, and well known in commerce, 
The Paris pint, which legally contains 
forty-eight cubic inches, would have 
anfwered all the purpofes of a meafure 
for fluids; and the Paris bufhel for dry 
goods. By thefe fimple means, all the 
well-known meafures might have been pre- 
Served, which have been in conftant ufe 
for centuries ; and the public would not 
have loft the French foot, and the poids de 
marc, which have been employed in a vatt 
number of mathematical, philofophical, 
and chemical calculations ; and in a mul- 
titude of books, French and_ others. 
There would have been no difficulty in 
-having accurate ftandards of thele mea- 
fures fent to the different departments, 
and their ufe enjoined by law. 
‘‘But this idea appeared tco fimple. 
It was wifhed not only to procure an equa- 
lity of weights and meafures for France, 
but to take a bafis of admeafurement from 
nature herfelf, to introduce it in every 
country and to give to the whole world 
the fame fyftem of weights and meafures. 
It was likewife fuppofed that their ac- 
MontTu_iy Mac. No. 78. 
curacy could never be impaired, or at 
leaft might always be reftored, fhould the 
original (tandards be deftroyed by fire or 
any other accidents, or injured by the lapfe 
of time. 
“¢ The plan of the new French metrical 
fyftem is certainly due to Borda, whofe 
knowledge and ingenuity are well known. 
I have often obferved to him that I 
was furprized that the fimple pendulum 
under the latitude 45° fhould not be’ 
afflumed asthe unity for a meafure of 
length, fince this ftandard is fo eafy to be 
found, and to be fixed with rigorous 
exactnefs, — : 
‘¢ His anfwer was, that it would not 
fuit their purpofe to ufe it, fince it would 
be neceffary, in determining its lensth, to 
employ the divifions of time, which them- 
felves arearbitrary. But furely time and 
its divifions muft be confidered as fixed and 
unalterable in nature, as long as the globe 
continues to turn on its axis with an equal 
motion. 
«© Themetre is the bafis of thenew French 
fyftem of admeafurement. It is a ten mil- 
lionth part of theare of the meridian from 
the equator to the pole. The lengthof a 
degree of the meridian has been mea/ured at 
45° of latitude; every thing therefore de- 
pends on the accuracy with which this has 
been afcertained. Now, the imperfection 
of our mechanical inftruments, joined to 
the comparative weaknefs of our organs 
of fight, the greater or lefs ferenity of the 
atmofphere, the difficulty of well diftin- 
guifhing the fignals, and many other ob- 
fiacles, all of thefe expofe the moft prac- 
tifed aftronomer, when ufing the beft in- 
ftruments, to commit errors, which he is 
afterwards obliged to corre& in an arbi- 
trary manner. _ With the moft accurate 
inftruments, he may commit an error of 
one toife in ten thoufand. This affertion 
is not founded merely on hypothefis, 
but on the experience of many years 
which I have had in trigonometrical fur- 
veys. 
“¢ Befides, the inftruments made ia 
France, not being conftructed with as 
much accuracy as they are capable of being 
brought to, I think I am authorifed to 
confider the error which I mentioned as 
more confiderable; but allowing only 
this, it would make the difference of a 
twentieth of a line in the metre, and 
certainly this is not inconfiderable. But 
I am perfuaded, from the dimenfons 
of the meridian taken for the metrical . 
bafis, that the error may eafily be double 
what I have mentioned, or the tenth of a 
line. , 
Dd. “ss The 
