Daily American organ. [volume] (Washington, D.C.) 1854-1856, 1855-12-21
[RrroRrrD yoR THE AMERICAN ORGAN
SMITHSONIAN LECTURES.
THE DISTURBANCES OF THE PLANETS.
BY PROFESSOR n. 8. SMELL, OF AMHERST COLLEGE.

Before entering upon the subject for the ever
ing, Prof Smell gave the illustrations of architect
ure in this country which he had forgotten to in-
troduce at the close of his of lectures upon
that subject.
In the United States, very little has been dore
in Gothic construction, except on q small scale.
Many churches have Gothic details but they are
not cathedrals; our simple worship does not re-
quire them A small edifice could not have the
complexity of a cathedral, without becoming puc-
rile in its details. The Library of Harvard Uni
yersty, in Cambridge, and Trinity Church, in New
York, were referred to as examples of Gothic
structures.
The Smithsonian Institution is Norman build
ing; 1t has semcircular and ntersecting arches,
cylindrical columns, beside PIERS and in their ar,
giles and the battlements of castellated edifces.
The most striking Norman feature, is the want Of
particular symmetry, while there is general
correspondence in the external parts The lecture
room was spoken Of as being admirably construct
ed for the purposes intended.
Having dismissed the subject of architecture lie
entered upon the subject announced for discussion.
The laws and force of motion are everywhere the
same. Whether pebble be thrown by the hand
ofa child, or world launched into space by the will
of the Creator, the same principles will forever
govern the motions Of each. If not disturbed, it
will forever move straight and uniformly. Ii a
second force acts it in another direction, it win
60 between, but still straight and uniformly. But,
II the second force acts permanently toward cer-
tre, it will forever describe an orbit about that
centre as focus. When stone Is thrown by the
hand, or ball fired by gun, the path of tho pro-
jectile is the commencement Of such an orbit
These laws are just the same in the movements of
common life, in the operations of machnery and
in the motions of the heavenly bodies This iden-
tity in the laws of terrestrial and celestial mechan-
les gives tho highest satisfaction to the thorough
student OF astronomy. He sees that he ia treadipg
on safe ground The mechanics of machinery and
locomotien might as vel be abandoned for some
new system, as the laws of astronomy.
s A fundamental fact In rotation is the tendency
to maintain a parallelism in its direction. The
earths axis is about parallel to ITSELF or the sea-
sons would be deranged. The moon brings each
pole in turn into our sight, because its axis is in
the same direction on all sides of u.s. All the
planets and satellites, as well the sun, do tho
same. Here the lecturer showed, by an instri-
ment called the rotascope, that ball suspended
freely, maintains parallel axis, however the frame
which sustains it is turned round, or tipped over
He likewise explained the boomerang, used by the
natives of New South Wales, exhibiting the actual
instrument and showing the experiment with card
models.
But the bodies in the solar system do not in fact
preserve an exact parallelism in their rotations,
because they are disturbed by other bodies The
sun and moon tend TO press the equatorial ring Of
the earth into the plane of the ecliptic; go that
every particle is urged by two forces-one in the
direction of rotation the other around the line of
equinoxes as an axis. Hence they tend to move
between; that is, the equinoxes retrogradc This
was shown By actual experiment with the rota-
scope.
In like manner the moons nodes move back.
ward, because while it advances in its orbit the sun
continually attracts 1t toward the eclipfic
IL the nodes Of two circles move backward, then
the poles of one must revolvc about those Of the
other
The north pole of the earth, for instance moves
round the pole Of the ecliptic. Il is now in the
end of the Little Bears tail, and the little fellow
appears to be whired about every day without
touching feet to the ground. But in $4,000 years
from this he will retire to rest and rise again every
twenty-four hours like other animals and then tho
Harp win be the polar constellation, and Alpha
Lyre will be the pole star.
Several experiments were performed with the
rotascope, 10 show the backward movement Of
nodes as phenomenon Of common mechanics
For instance, when the ball, which was swung IN
gimbals, was set spinning very rapidly on a verli-
cal axis, and the outer ring confined if the exper-
imenter carried the frame around himself In the
same direction, the ball revolved quietly; but il
in the opposife direction, the ball Immediately
whirled over, 80 as 10 revolve the same way This
was repeatedly shown, and explained.
Again, IL the outer ring is spressed aderGys
while the ball Is whirling on a horizontal aka, tho
axis turns up dorm II the inner ring Is crowd
ed up or doon, the outer ring turns round side.
,cays
And, once more, the inner ring with the bail
was hung upon wire let down from the ceiling,
by stem ak inches long, fixed firmly to the ring
the ball was then whirled, and the whole placed
horizontally, and dropped But, instead OF falling
down beneath the wire, il remains horizontal and
whired round, though weighing fifteen pounds,
and the centre OF the ball being more than foot
from the wire by which it was suspended
Another disturbance Of the earth and moon and
many planets and satellites Ia that which Is called
tire ddvance Of opsides. The extremities of the
elhptlcal orbits advance in the same direction "a
the bodies themselves. This is caused by the at
traction Of bodies outside, which diminish the ten
dency to the centre most at the apheon point so
that the planet shoots forward little too far before
turning to approach the centre. This was illastfa.
ted etrkingly, by suspending globe, ard swing
ing IL round In an elliptical orbit The extrcmtes
advanced the same way the globe moved, in which
ever direction 1t was swung. And it was explained
as arising from the central force being too much
diminished, as IN the planets.
lfthcre were but two bodies in the system, they
would describe their mutual orbits, without change
forever But the introduction Of third body,
causes changes The disturbances in the solar
system, in which there are hundreds of bodies, are
almost numberless. The two described this even.
ing are among the most important. And they 90
on, accumulathg forever, but do not produce dc.
rangement as the student would at first suppose,
The Being who made them, governs them by the
same laws, Which operate in all the movements Of
everyday life.
The lecture was largely attended, and the atten
ton of the audience was firmly held throughout
the whole Of il. The experiments were Of the
most convincing character, and 50 perfectly plain
were the illustrations shown, and the conclusions