MEASl 
Imwever, far too ntmierous ami powerful to 
be cafily overcome, or removed, in matters 
of itifinitely less moment. W e caiinot, 
theiefore, entertain the slightest hope that 
national partiality will be subdued in eveiy 
quarter of the globe, so as to produce a ge- 
neral resignation oi favourite methods, in 
order to adopt a new one recommended by 
a congress of philosophers, which it would 
be equally difficult to assemble, or pievail 
upon to agree to any plan unanimously. 
The theories of eminent men on this subject 
are useful, and deserve attention, as they 
may suggest improvements of great impor- 
tance. Huygens proposed the length ot a 
pendulum that should vibrate seconds, to 
be measured from the point of suspension 
to that of oscillation. The third part of 
this pendulum he termed a horary foot, and 
such he recommended should be the stand- 
ard by which the measure of every toot in 
Europe might be regulated. Admitting his 
plan to be woi thy of adoption, and an experi- 
ment made, it appears that the Paris foot 
would bear a proportion to the horary foot 
of 864 to 881, which is demonstrated in this 
manner : The length of three Paris feet is 
864 half lines, and that of a pendulum vibrat- 
ing seconds consists of 881 half lines. The 
principal objection to this ingenious sngges- 
tion of Hnygens is founded on the assump- 
tion that the action of gravity is the same 
in all parts of the globe, which is certainly 
not the case ; consequently, instead of its 
serving universally, it would be useful only 
in those places which lie under the same 
parallel of latitude. Thus, if each different 
latitude had its foot equal to -the proposed 
third part of the pendulum vibrating seconds 
there, any given latitude must have a differ- 
ent length for the foot. Exclusive of this 
objection, there would be a second pro- 
ceeding from the difficulty attending the 
exact measurement between the centres of 
motion and oscillation, which is such, that 
it is highly probable no two persons would 
agree in their accounts of the space. 
Many attempts and expedients were sug- 
gested after tlie rejection of the above 
plan, with similar want of success. This 
circumstance did not escape the notice of 
the Society for the Encouragement of Arts, 
Manufactures, and Commerce, the officers 
of which, with a commendable zeal, adver- 
tized a premium of one hundred guineas, 
or a gold medal, as a reward to those who 
would propose the approved means “ for 
obtaining invariable standards for weights 
and measures, conmiunicable at ail times 
JRE. 
and to all nations.” This invitation pro- 
duced a communication troni Mr. Hatton, 
in 1779, in wliich he proposed the applica- 
tion of a moveable point of suspension to 
one and the same pendulum, and by this 
means he intended to accomplish the full, 
effect of two, the difference in the lengths 
of which was the desived measure. 
The ideas of Mr.. Hatton were approved 
by the ingenious Wiiitehui'st, vviio im- 
proved upon them, and invented some verjr 
curious and excellent machinery ; besides 
wliich, he published, eight years after, a 
work entitled “ An Attempt towards ob- 
taining invariable Measures of Eength, Ca- 
pacity, and Weight, from the Mensuration 
of Time,” &c. Mr. Whitehurst thought it 
convenient and proper for attaining this 
most desirable end, to endeavour to obtain 
a measure of the greatest convenient length 
from two pendulums, the vibrations of which 
are in the ratio of two to one, and of lengths 
agreeing with the Englisn standard in whole 
numbers. 
To explain our philosopher’s intentions 
more fully, let ns admit the supposition that 
the length of a pendulum vibrating seconds 
in the latitude of London is 39.2 inches; 
the length of one vibrating 42 times in a 
minute amoimts to 80 inches ; by the same 
unerring rule, another vibrating 84 times iii 
a minute must be 20 inches ; the difference 
resulting from these data is 60 inches and 
Ins proposed standard measure. Pursuing 
his experiments to the very acme of perfec 
tion, he found the variation in the length of 
the two pendulums to be ,59.892 inches, 
instead ot 60, arising from an error in the 
assumed length of the seconds’ pendulum: 
’ It is generally admitted, that Mr. White- 
burst has succeeded in his design, and de- 
monstrated to the learned how an invariable 
standard may at any time be found for the 
same latitude. Besides this discovery, the 
world is indebted to him for the accurate 
ascertaining of a fact of very considerable 
importance in natural philosophy. A per- 
son tvho wrote with ability on this point 
observes, wdth respect to the fact just men- 
tioned, ‘‘ The difference between the length# 
of the rods of two pendulnms, whose vibra- 
tions are known, is a datum troin which may 
be derived the true lengths , of pendulnms, 
the spaces through which heavy bodies tall 
in a given time, with many other particular.? 
relative to the doctrine of gravitation, the 
figure of the earth,” &c. Mr. Whitehurst 
perceived from this experiment, that tlie 
length of a second’s peudulum vibrating in a 
