300 
rapid motion, suppose it to be made to 
revolve with a smaller velocity, and 
the dense nucleus would remain in 
the centre, while the train would be 
revolved, and form a globe like the 
earth. 
24. Poise a lever of wood or iron on 
a pivot, with a fixed large ball at one 
end, and on the other end place a ball, 
with a hole through it, by which it will 
readily slide; turn the whole, and it 
will be found that the sliding ball will 
soon adjust itself in equilibrio; then 
put another small sliding ball near it, 
and the two balls, when the whole is 
again revolved, will adjust themselves 
nearer the centre; thus it will be evi- 
dent, that, if the first ball could have 
been gradually increased while in mo- 
tion, it would have described an 
ellipse round the other. Such is the 
cause of the elliptical motions of the 
planets; the earth, for example, ac- 
quires greater momentum in one part 
of its orbit than in another, owing to 
more water being opposed to the mo- 
tion of the sun in one hemisphere than 
in the other; the action of moving wa- 
ters increasing the momentum of the 
mass; it then descends towards the 
centre, as, When the sun opposes the 
southern hemisphere, the earth is in 
its perihelion; but, when the san op- 
poses the northern hemisphere of more 
land, the re-action of the mass becomes 
less, and it ascends from the centre 
or sun, and is in its aphelion. 
25. Suspend a silver-paper globe, 
six inches in diameter, by -a thread of 
silk, from the ceiling of a room, and 
suspend another, only one inch in dia- 
meter, a yard distant; then act on 
both globes with any broad surface, by 
transferring the motion of the broad 
surface through the air to the two 
globes, and, while both are affected, it 
will be perceived that the smaller 
globe will also be affegged by the mo- 
tions of the larger one. The large 
globe may be considered as the earth, 
the small one as the moon, the broad 
surface as the sun, and the intervening 
air as the medium of space, through 
which the motions of the sun are ra- 
diated to the earth and moon. 
26. Take a broad tub of water, and 
by the mechanism of Busby’s Hydrau- 
lic Orrery, make a globe in the centre, 
urge the water with a gentle circular 
movement, then place four smaller 
bodies at different distances from the 
central globe, and it will be found 
that the four small bodies will perform 
2 
Experiments illustrative of the New Philosophy. 
[Nov. 4, 
revolutions, the square cf whose times. 
are as the cubes of their distances; for 
the force of the central ball being dif- 
fused in the fluid, and therefore in- 
versely as the squares of the distances, 
the resulting proportions will be ane- 
cessary consequence. This experi- 
ment beautifully exemplifies the phe- 
nomena of Jupiter and his satellites, 
and the intervening water represents 
the medium of space. Of course the 
same principle of action applies to the 
sun and planets. 
27. Take a glass tube, with a bulb 
at one end, half fill the bulb with a 
coloured liquid, balance the tube on a 
pivot, then revolve the whole, and it 
will be seen that the liquid will rise 
out of the bulb towards the centre of 
motion, or the pivot. This analogi- 
cally illustrates the cause of the tides ; 
the earth revolves round a pivot or 
fulcrum of the earth and moon, and 
the waters on the earth rise towards 
the pivot or fulcrum of both, 
28. Put two bungs on water, a foot 
distant, and they will go together, or 
appear to attract each other ; but load 
them with lead, or use pieces of elm 
or oak, so that no part of the bulks 
float above the water, and no approach 
or attraction will be visible: proving 
that their approach is owing to the 
action of the unequal columns of the 
air on their outer and inner sides, and 
that no attraction existed. This ex- 
plains all the phenomena of capillary 
tubes, ascent of fluids on sides of glass, 
and between glasses, suction, sup- 
posed attraction of plummets by moun- 
tains (as at Schehallien), of poised 
leaden balls (as in Cavendish’s expe- 
riment), of ships on boats, &c. 
—— 
To the Editor of the Monthly Magazine. 
SIR, 
A the time your 360th number ap- 
peared, I was too much occupied 
fo be able to offer those remarks on 
the geological theory advanced by 
Mr. Cumberland, in p. 301 of your 
52d volume, which I then intended, 
and still think it proper to request 
your permissionto make. Throughout 
his paper, Mr. Cumberland contends 
for the sudden production, by means 
of the present laws of crystallization, of 
probably two miles’ thickness of the 
strata, of the south-eastern parts of 
our island; and, in so doing, appears 
to me most unfairly to overlook the 
evident proofs of slow and successive 
creation, 
