The republic. [volume] (Washington [D.C.]) 1849-1853, 1851-05-01
From a.. London Globe, .Aprii g..

A0GAGlOn 6okGn kS0nOoH0O
The experiment now being exhibited in Paris, by
which the durnal rotation Of the earth II rendered
pnlpable TO the Senses 10 OF tho most kAble
Of the modern vcri6catons Of theory. Although the
denomination by which the rotation of the earth has
been established be such TO carry conviction TO
the minds Of all who are capable Of comprchending
it, TO which nothing can be imagined to add either
force or clearness, nevertheless even the natural
philosopher himself cannot regard the present ex,
pertinent without feelings Of profound interest and
satisfact:on, and to tho great mass, to whom the
complicated physical phenomena BY which the rota-
ton of the earth has been established are inconpre
hensible, this experiment 10 invaluable. AZ the
centre Of the dome Of the Pantheon fine wire is at
tached. from which sphere OF metal, four or hve
inches In diameter, il suspended TO hang near
the floor Of the building This apparatus l. put in
and concentrated within il, il placed circular Ia
BILE, some twenty feet in diameter, the circumfer-
enee Of which is divided into degrees, minutes,
&c., and the divisions numbered. Now, 1t can be
shown by the most elementary principles OF mo
chanics that, supposng the earth to have the dur
nal motion upon its axis which 10 imputed to it,
aud which explains the phenomena Of day and
night, &C., the plane in which this pendulum vi
brstes viii not be affected by this durnal motion,
but will maintain strictly the same direction DUR
ing twenty four hours. In this interval. however,
the table over which the pendulum 10 suspended
will continually change it, petition in virtue OF the
diurnal motion, 10 a. TO make complete revolu-
ton round its centre.
Since then, the table thus rsvolvcs, and the pen
winch VlOfuteo over ~ OOc0 not TeVOIVop inc
consequence il that line traced upon the table by
point projecting from the bottom Of the ball will
change IT. direction relatively TO the table, from
minute to minute and from hour to hour, that II
such point pencil and that paper were spread
upon the table, the formed by this pencil dur
ing twenty -four hours would form system Of lines
radatng from the centre Of the table, and the two
lines formed after tho interval Of hour would al
ways form angle with each other Of is deg, being
the twenty fourth part OF the circumference. Now
this il rendered actually visible to the crowds which
daily flock 10 tho Pantheon to witness this remarkA-
BILE experiment. The practised eye of correct
observer, especially If aided by proper optical
instrument, may actually see the motion which the
table has, in common with tho earth, under the
pendulum, between two successive vibrations. II
IL, in fact, apparent that the ball. or rather the
point attached to the bottom OF the ball, docs NOT
return precisely TO the samc point Of tho circum-
ference Of the table after two successive vibrations
Thus il rendered visible tho motion which tho ia
bic has In common with tho earth. II 10 true that
correctly speaking, the table does not turn round
ts own centre, for although the table be turned In
common with tho surface of tho earth, round the
earth's axis the point Of suspension OF tho pendu-
lum turned also in the same time round the same
axis, being continually maintained vertical
above the centre Of the table, The plane in which
the pendulum vibrates does not, however, partakt
Of the motion, and, consequently, has the appear
ance Of revolving once in twenty four hours over
the table, whiie In reality, il il the table which
wolves once in twenty -four hours under 1t.