274 
that what he had taken for a fpot was a 
ftar. At 7 minutes 12% feconds paft two, 
the black point had reached the fun’s 
edge, when the fimall Hine of light which 
yet grazed it was inftantaneoufly extin- 
guifhed ; a phenomenon which leaves no 
room to doubt that it was fome body 
which had paffed over the fun. 
Citizen COULOMB read a memoir; in 
which he gives the refult of a number of 
experiments calculated to afcertain the 
quantum of action which men may con- 
tcibute by their daily labour, according 
to the diiferent modes in which their 
force is employed. . 
Two things are to be diftinguifhed in 
the labour of men; the effeé produced 
by the exertion of their force, and the 
fatigue which they undergo to produce 
that effet. In the carriage of burthens, 
the effect produced is the greater as in 
proportion to the greater weight of the 
burden each journey, to the greater dif 
tance of the carriage, and to the greater 
length of time the labour lafis; fo that 
two men will have produced equal effects, 
2f one of them has tranfported a double 
weight to a finele diftance, and fhe other 
a fingle weight to a doube diftance. 
Whether the force of men be employed 
in carrying loads, in moving machines, 
tilling the earth, or in any other labour, 
the effect muft always be eftmated by a 
yeight equivalent to the refifance it will 
have to furmount, multipled by the 
fpace which that refiftance vill have to 
pafs while the labour lafts. 
Yo overcome refiftance, nan exerts a 
‘preffure on a point which hefets in mo- 
tion, and the fatigue confift of the ex- 
tent of the preflure, of the véocity of the - 
point prefied, and of the tme that the 
aétion lafts; fo that the fatgue may be 
exprefied in numbers, by th: produce of 
a weight equivalent to thepreffure ex- 
erted, multiplied by the vescity of the 
point prefied, and by the tme that the 
preflure lafts. 
How are we to combineche different 
degrees of preffure, of velcity, and of 
time, fo as that a man, wth equal fa- 
tigue, may furnifh the greaeft quantity 
of action? 
In the folution of this inerefting pro- 
lem, Citizen CouLomBapplies the 
principles here laid down. He confiders 
ducceflively the labour of a 1an who rifes 
by a ladder, or a ftair-cafi or ome who 
walks over an horizontalplain, either 
carrying a load or without ne, carrying” 
~.. the load in his arms or orhis back, or 
earrying it in a barrow, 
National Inftitues sth Germinal, 1798: 
% 
, 
Pec ys 2 : : . ~ 
Se oe ee - ¥¢ : 7s 
4 p ‘ 


In analyfing the labour of carriage, he 
diftinguifhes two things in the effeét pro- 
duced; one is the a&iual carriage of the 
load, which is the ufeful effeét. But mar 
alfo tranfports his own body along with’ 
the load, and afterwards réturns without 
aload, which is the fecond part of the. 
effect ; it requires a certain quantity of 
action, and, confequently, a certain fa~ 
tigue, which does not at all contribute 
to the ufeful effet, and which thould be 
deduéted from the total a&ion, in deter- 
mining the real effect which tefults fron 
that action. “ 
Citizen CotuLomB next diteéts his 
enquiry to the labours of men employ- 
ed in driving and finking ‘piles, of mer’ 
who work on handles (as the whipftaff of 
4 fhip’s helm, the-rourice of a printing- 
prefs, &c.) or with a fpade in digging; 
&c. ‘The refults obtained by the analyfis 
of his different labours, give quantities 
of action lefs confiderable than thofe 
which moft authors reckon upon in the 
calculation of machines; this proceeds 
from thofe authors commonly reafoning 
by experiments, which only laft a few 
minutes, and are performed by fele&t men. 
_ The fame author prefented a new edi- 
tion of his enquiries into the methods by 
which to execute all forts of hydraulic 
labours under water, without having re- 
courfe to draining, or emptying,.of any 
kind. It is to be hoped, that the means 
propofed in this work may then be duly 
applied, when the return of peace fhalt 
allow the entering on conftruétions of ge- 
neral and fuperior utility, and which can 
only be attempted properly by govern- 
ment. 
[ The remainder of this Sitting will be given in a 
future Number | 

TOUR OF ENGLAND. 
(Continued from page 194.) 
Journal of a Tour through almo# every county 
in England, and part of Wales, by Mr.Joun 
Housman, of Corby, near Carlifles whe 
was engaged to make the Tour bya gentle- 
man of diftinG@ion, for the purpofe of col- 
leGting authentic information relative to 
the flate of the poor. The Journal com- 
prifes an account of the general appearance 
of the country, of the foil, furface, build- 
ings, Sc. with obfervations agricultural, 
commercial, &c, 
CTOBER izth, went from South- 
ampton to Wimbourn, in Dorfet- 
fhire, twenty-nine miles. The road very 
good; foi] various; it is net Temagaar 
or 
FOR: 
’ 
> 
