PSYCHIC FORCE AND PSYCHIC MEDIA. 
35 
and this hemispherical bowl rests in the water, supported at 
the end of an arm of an iron stand, placed some two inches from 
the board and unconnected with it. Into this bowl, inside 
the vessel, Mr. Home placed the tips of his fingers, and after a 
little time the balance showed slight displacements. These, 
however — and here is a very important point — were displace- 
ments in both directions, upwards and downwards, but it is 
only to one of these that we are more particularly referred. 
Now, let us examine this experiment very carefully. It is at 
once obvious that any displacement of the centre of gravity of 
the whole system must produce motion in the board. Any- 
thing, therefore, which tends to change the position of the 
centre of gravity from this, its original position of equilibrium, 
causes motion in the board which will obviously be registered 
on the balance. But just as the centre of gravity may be 
thrown either on one side or on the other, so we may get the 
end of the board tilted up or down ; or, in other words, we may 
have what is ascribed to “ a diminution of the force of gravi- 
tation as well as an increase ! ” 
We would wish most forcibly to impress the significance of 
this source of error in this so much vaunted experiment on our 
readers, as it is typical of the whole set we are criticising. For 
its better elucidation the following diagram is necessary : — 
a B is the board resting on the fulcrum or knife edge at c, and 
the end b fixed to a self-registering spring balance. The bowl 
D e we will suppose placed, as it really was, immediately over 
c (although the position is indifferent), and the spring balance 
adjusted to equilibrium. It is obvious that any displacement 
of the centre of gravity of the bowl will amount to a displace- 
ment of the centre of gravity of the whole system, and it may 
be displaced in two directions. Firstly, let us suppose it dis- 
placed to g. The board a b becomes then immediately a lever 
of the first kind, with one force acting at h, and the other at b, 
and the fulcrum at c. Now, although the distance hc will 
always be very small, the weight of the bowl and its contents 
is very large, so that the moment will be quite appreciable and 
the movement will be duly magnified at b in the ratio of cb to 
hc. By this motion the end b will rise. Similarly, if the 
centre of gravity be displaced to g" there will be the force 
