THE SCIENTIST. 
Proceed n^^s of the Academy of Science. 
The Human Mechanism. 
By. Joseph Sharp, M. D. 
No doubt to consider man as a machine 
is on the first thought, a shocli to our 
higher intelligence. Abhorrent to a cer- 
tain degree to our consciousness, that 
part of us that has recently been desig- 
nated, as "simply the part perhaps of an 
outer concentric Psc3a^hic circle ; the rest 
of circumference of which we could never 
know," However we all readily admit 
that the economic value of a man, de- 
pends entirely on what and how much he 
does in a given time. In other words it is 
his '^mechanical daily duty,'' the product 
of three quaniities, the efi'ort the velocity 
and the number of units of time per day 
during which work is continued." Cer- 
tainly just the estimate we would put 
upon the utility of a machine. 
Let us consider the theory of machines 
as set forth in the article on Applied Me- 
chanics in the Encyclopedia Britan- 
ica and see in how far it applies 
to the human Mechanism. First, the parts 
of a machine C(»nsist of the frame and 
mechanism. In considering the frame the 
stability and the stifiness and strength of 
the frame and mechanism are of primary 
importance. In considering the machine 
in motion, we natiu ally take up the ques- 
tion in the following order. First, some 
natural source of energy communicates 
motion and force to a piece or pieces of 
the mechanism called the receiver of 
power or prime mover. 
Secondly, the motion oi- force are trans- 
mitted from the prime mover through 
the train of mechanism to the working 
piece or pieces and during the transmis- 
sion the motion and force are motlified 
in amount and direction, so as to be ren- 
dered suitable for the purpose for which 
they are to be applied. 
Thirdly, the working piece or pieces 
by their motion, or by their motion and 
force -combined produce some usefid 
effect.' This is considering the pheno- 
mena of machines in the order of causa- 
tion. While for simplicity's sake proba- 
bly, the order adopted by the above 
named vvriter is the best, that is first the 
modification of motion and force by the 
train of uiechanism, second, the efi'ect or 
purpose of the machine, and last, the 
action of the prime mover. Giving the 
following classification: 
I. Pure mechanism under which we 
have, motion of a point, 2, motion of the 
surface of a fluid, 3, motion of a rigid 
solid. 4, motion of a pjir of pieces, 5, 
motion of a trdin of pieces, 6, motions 
of sets of two or more connected pieces 
or an aggregate combination. 
II Applied Dynamics, under which 
comes 1, balanced foi-ces, 2, defleeling 
foi-ces. 3, working of machines of varying 
velocity. 
in. Purposes and eftects of machines. 
1, observing machines, (a) counting ma- 
chines, (b) measuring machines, (c) 
copying and drawing machines, (d) 
weighing machines, (e; recording ma- 
chines, 2, working machines, (a) lifting 
and lowering solids, (b) hoi-izontal trans- 
portations, (c)projecting solids, (d) lift- 
ing fluids, (e) propelling or projecting 
fluids, (f)dividing bodies, (g) shaping by 
removal of a pai t of these machines, (h) 
uniting into fabric machines, (i)sound 
producing machines, (j) miscellaneous 
machines. 
IV. Applied enegetics or theory of 
prime movers, under which we have, I; 
prime movers in general efficiency. The 
useful work ofthe prime mover is the ener- 
gy exerted on the piece it directly drives 
and the ratio which this beais to the 
source oi energy is the efficiency. 2; 
source of energy, (a) strength of animals 
(b) weight of liquids, (c) motion of fluids 
(d) heat, (electricty and magnetism.) 
Following this classification, let us 
then look at the human mechanism. 
