148 Serentific Intelligence. 
when w= a, or the weight used is equal to the grees depend- 
ing on the weight of the limb and its appendage 
en the weights were lowered as well as aaaed at fixed rates, 
and no rest at all permitted, the law of fatigue becam 
oe ee (4) 
where n, ¢, are the shina and time of lift, A is a constant 
depending on experiment, and f is a a ais involving the time 
of lift (7) at which the maximum work is don 
Equation (4) denotes a cuspidal cubic. 
yhen the weights are held on the palms of the Sear 
hands, until the experiment is stopped zt fatigue, the law becom 
(w+ a)’t= | 6 
where ¢ is the whole time of holding o 
a equation denotes a cubical Re arols. 
aw of Fatigue seems, in itself, probable enough, but of 
course ois real value depends on its agreement with the results of 
erime 
ex nt. 
te W denote the total work done and FR the rate of work, the 
law becomes, simply 
W x R= const. bi 
If different limbs, or animals were used, each working in net 
way, and under its own conditions, the Law of Fatig gue ‘would 
become— 
WR=W.R, + WR, + WR, + &e. (7) 
and the problem for the engineer would be, so to arrange the 
work and rate of work of each agent emplo ed, as to make the 
of i rk b 
equation (7 \. 
n using equation Lo?) in ar concluding paper, detailing the 
results of experiments made on Dr, Alexander Macalister, 
Haughton treats a as an witkti own quantity, and finds from all 
the observations its most probable value to be— 
‘ ‘a@ = 5°68 lbs. 
This result was compared with that of direct measurements made 
on Dr. Macalister himself, and indirect measurements made on 
the dead i sila from all of which Dr. Haughton enalided the 
value of a t 
a = 5°56 lbs. + 0°125 (possible error). 
This result agrees closely with that calculated from the law of 
fat 
om should be added that a Sie aes was ciclo by Dr. Haughton 
Dr. Macalister to make the experiment conclusive by direct 
Genputattont of his scapula, a course ne ich he, unreasonably, 
objected to, as he draws the line of “vivisection” at frogs.— 
Nature, xxii, 554. 
