Los Angeles herald., 1906-07-29
BROdRf5> IN SutNCt AND INDUSTRY E6|zHIE E4Ell

mid for the plumb-bob, and the greater attrac-
tion OF the large body, the earth, for the plumb
bob. The weight of the pyramid having been
estimated, the weight of the earth will be cal
culated by multiplying the pyramids weight by
the number of times the attraction of the earth
for the plumb-bob is greater than the attraction
OF the pyramid for the plumb-bob. From the
standard thus fixed the weight of all other bodies
in the solar system be estimated.
1t is easy enough to ascertain just about how
many cubic feet of material there in the
Pyramid One cubic foot of the rock Professor
Newcombe will take and weigh on an ordinary
pair of scales. Suppose that it weighs 125
pounds. Then, if the number of cubic feet in
the pyramid be multiplied by 125, the result
will be the total weight of the mountain. But
the mountain attracts in proportion to it's mass
and so, likewise does the earth The pendulum
tells the amount of attraction exerted by the
mountain, and the attraction of the earth, (Which
we call gravity is exactly known. Hence, it is
easy enough to figure out just how many times
as heavy as the mountain the entire planet is
The dimensions of the earth being accurately
known the number of cubic feet the planet con-
tains may be readily ascertained, But it would
not do for Professor Newcombe to multiply this
number by 125 in order to find out the weight
of the globe in pounds because the crust is much
lighter than the interior the density increasing
toward the centre of the sphere. An average
piece of the crust is only about two and a half
times as heavy as an equal bulk of water, whereas
a fragment of the inner core is eleven times
as heavy water.
ESTIMATING THE DENSITY
Nearly all the seas have been mapped and
sounded, and it is known that they have an
average depth of somewhat less than three miles
shoalng considerably toward the poles. It will
be, then, mere matter of arithmetic for Pro
fessor Newcombe to determine approximately
how many cubic feet they contain, and to as
certain the total avoirdupos represented by the
salty fluids which cover more than two-thirds
of the globe.
1t is known that the number Of cubic miles in
the earth is 250 800 600, 900 and each cubic mile
contains 1472OO, 100000 cubic feet; scientists
have long told us that cubic foot of earth,
upon the average, weighs 5.67 times as much as
cubic foot of water, or 354 pounds G ounces
avoirdupois. there's a frstcass brain tester
/ Get out half dozen well sharpened pencils and
"A ream of paper and if you are lucky YOU will
reach result something like 5,00S, 900 600 600
100000 tons as the weight of the world accord,
ing to present standards. Then watch Profes.
sor Newcombe, for he, with his nicely adjusted
implements, is likely to make some discoveries
which viii send the results of the effort madc
to weigh the earth half a century ago and the
result Of your calculations, into ancient history
1t was over fifty years ago that the first az.
tempt TO weigh the earth was made for the bene.
fit of the astronomers and the torment of the
school boy, An English scientist by the name
of Airy undertook the work and great credit il
due him. for he il was who evolved the pendu.
lum system of weighing the world and it 4
practically this same system which will be used
by Professor Ncwcorhe.
Under Airy's direction. penduluns were swung
p at the top and the bottom Of coal pit near