202 
<<‘ Dhe ee to the north ought to be 
Jarger than the others; however, notwith- 
ftandingallthe care and accuracy beftowed 
on this fubject, itwas!found that under the 
latitude 43° 31’ ihedeprce mealured 57,048 
toifes; and in45° 43',it was 57,040 accord- 
ing toone meafurement, and 57,050 accord- 
ing to another. 
<' This difference of ten toiles thews 
that I have not exaggerated in fuppofing 
it poffible, and even Bpacebe that 
an error might be committed, amounting 
to no lefs than fix toifes ina ingle degree. 
«* Henee it may be feen that even fuch 
accurate aftronomers as Caffini and La 
Caille have not been able to come nearer 
the truth than one toife in ten thoufand, 
and I fufpeét never will make a clofer ap- 
proximation; and from their own calcula- 
tions the metre ought to be 3.0807 French 
feet. 
‘* Since, however, the decree of the 
18th Germinal fixed it at 3.0794. French 
feet, Bouguer’s admeafurement of the me- 
ridian at Peru muft have been adhered to, 
in which the elevation of the earth under 
the equator is reckoned at a three hundred 
and twentieth of its axis. But who is 
not ftruck with thefe arpitrary hy pothefes, 
and with the difference which exifts be- 
tween thefe two bafes for determining the 
metre, each of which appears as probable 
as the other, and yet differing the tenth of 
a line! 
fions of the metre are ftill fubject to a 
greater uncertainty than the length of the 
fimple pendulum under a given latitude; 
and it cannot yet be affirmed with truth 
that the length of the metre is juftly given, 
that it is invariable, and fixed by a natural 
ftandard. 
“© It has befides been taken for granted 
that the curvature of the are of the meri- 
dian, from the equator to the pole, forms a 
erfe&t ellipfis. But this is ftill a mere 
aa for the degrees meafured by 
Beccaria at Turin, by ‘Liefeanig i in Hon- 
gary and Auftria, and by La Caille on the 
coafi of Africa, feem to prove that this 
curvature is by no means a perfecily regu- . 
lar ellipfis. "This therefore would make 
it impoflible to calculate the length of the 
whole meridian from the meafurement of 
only a few degrees, and confequently 
would throw an equal difficulty on -the 
valuation of the true length of the 
metre. 
<< Inthenew Fath fyfemevery divifion, 
from the higheft to the loweft, is made by 
tens. This undoubtedly affords the 
greateft facility for calculations; butit may 
he doubted whether this mode of divifion. 
_ inftrument- makers. 
In my opinion the true dimen- 
Profe effor Byers on the French Weights and Meafuures, [O&ober 1, 
is equally eligible for mechani I am 
Hs Aye that actual fubdivifions of 4 
4, 4, +, &c. may be made with muctr 
more accuracy than thofe of tenths. 
Thefe laft area real {chool of patience for 
In practical -me- 
chanics it is an undoubted truth that it is 
impoffible to divide by tens and hundreds 
with the fame ‘exaétnefs as by two; and 
this is fhewn particularly in the éonftrue: 
tion of o€tants, quadrants, theodolites, 
graphometres, &c. 
«< If the new metrical fyftem fhould 
come to be adopted univerfally, our fuc- 
ceffors would ceafe to have any connection 
with the fcience of their predeceffors. 
Let us imagineour potterity employing the 
New Republican Calendar, ufing inftru- 
ments divided into 160 degrees, and di- 
viding the day into ten hours, under- 
taking to read aftronomical, geographi« 
cal, and nautical abiceraiaed made in 
pat times. To underftand thefe obfer- 
vations, they muft be reduced at every 
line, to tranflate our prefent language of 
calculation into their own idiom, and all 
their time will be taken up in reducing the 
antient divifions of time and fpace into 
correfpondent modern terms. Soon they ~ 
will be fatigued with thefe Ree petually re. 
curring calculations, and wil IE reje€t alto- 
gether all books of ‘the old ftyle ; and 
thus the fruit of fo much laberious re- 
fearch made by our predeceflors will be | 
entirely thrownafide. The famewill hap- 
pen in works of natural philofophy and 
chemiftry, in every cafe where weights 
and mea(ures are concerned. 
“‘ This is a real and powerful obftacle 
to the progrefs of arts and fciences ; for, 
to bring to perfection the fciences of 
aftronomy, geography, and hydrography, 
it is pa aticularly neceflary to compare 
the refult of antient and modern obferva- 
tions, 
<‘ Cenformably to the new fyftem the 
day was to be divided into ten hours, the 
hour into 100 minutes, and the minute inte 
100 feconds. 
‘© The two excellent watch-makers, 
Berthoud and Breguet, along with fome 
others, made however remonitrances with 
the dire€tory, in the name of their whole 
body, on the great inconveniences which 
would enfue from fuch a divifion of time, 
and the particular injury which the whole 
trade would fuffer thereby. é 
‘© This had theeffeét of obtaining from 
the government a refolution to poftpone 
this innovation. I have only feen’ in 
Paris two clocks conftructed on thefe di- 
vifions, ~ One is a large — fet up in the 
, middle 
