Evening journal., 1910-09-16
WEIGHS THE EARTH.
LIKE A BIG CHEESE.
This Terrestrial Sphere Tips
Beam at Seven TrilliOn
Tons
AND THE SUM
WELL FORGET IT

NEW YORK, Sept 16.-Scores of
studious looking persons crowded q
class room OF the College OF the City |
of New York when Reinhard A. Wetzel |
weighed the earth There were DEM
onstrations of photography in colors |
and Of wireless telegraphing and tele-
phoning. but soon after the doors of
the college were opened at p. M, Il |
was made plain that the throng was !
chiefly interested In Wetzel and the
wonderful machine by which he had
found that this planet weighs 7,000,-
900 5000 tons or 5000 900 900 ,000,-
600 900 900 100000 grams.
The spectators, who stood about
near blackboard upon which were
many figures and signs, were chiefly
men with gray hair, middle-aged wo-
men with Eyeglasses and youths who
asked questions. Wetzel explained
that his method was not new but had
been used by Henry Cavendish in
Cambridge University in England as
far back as the Eighteenth century.
But Wetzel went on to say with
pride that he was the first man in
America to compute the weight OF the
earth and the planets. Two other
men had made calculations which diff
] AtItu AAOlh AnOnt ht saw NAN WIN W
| Thursday by only a fraction Of a per
cent.
The apparatus Wetzel used Is
/ known as torsional gravitauonal
balance. Il is an upright telescope
affair, through which a fused quartz
filament Is suspended from the top.
Two silver balls are balanced on a
piece of steel wire. A framework
within the base contains two large
lead balls, which are moved back and
forth beside the smaller silver balls
to adjust the instrument and to equal
ize the attraction of the suspended ar
mature.
The instrument Is set upon a pedes-
tai of concrete embedded in the reath
about 10 feet, just above the bedrock
fupon which the college buildings are
'constructed. From a powerful electric
globe placed at one side of the stand
a ray is thrown by magnifying glass
against a mirror to which the thread
of quartz fiber Is attached. When the
suspended silver balls have been ad-
iusted by means Of the larger lead
balls. a ray of light is thrown upon
canvas marked OF I'm scales. The
rest of the process is purely mathe-
matical
MASSES attract one another" said
Wetzel TO his audience yesterday, "and
have used the theory Of attraction as
the fundamental rule Of my calcula-
! tons"
, He explained that the degree Of at
: traction In certain parts OF the eartf
. is known to scientists, and, hgurint
?. with that known degree. he was abl
S to find the earth contained 100000,
= 600 900 tons OF matter.
d Hundreds of questions were fun
J. at him. Some one asked If he Ia
N been able 10 determine how much
the earth was composed Of minerali
81 others wanted to know how muS
ST Mars and Jupiter weighed.
Of To these questions he answered
o. pointing to the blackboard made
ar plate glass with one side frosted an
n bIackened. where the names of plane
IA appeared, each with the weight wri
d ten beside It.
+ Some of the interesting figures TO
m low:
"a 100000 grams.
600. 600 600 grams.
4 Jupiter-1 $50. 900 000, 900, 100000 600
q O0O.O0O.OOO grams.
- Saturn - 563.0OO0O0, 100000, 1000
n OO0,000.00O grams.
"a Venus-4's7O 900 600, 900 ,OOO, 10000
100000 grams.
Neptune-1O5. 900 600, 900 900 900, 900
600 100000 grams.
Mercury-263 900 5000 900 900, 900
h, 100000 grams.
Wetzel explained that, using tn
earth as a unit for his calculation
e. the weight of the planets was easil
n found. He also said II not dreai
at that If a hole we're dug through Il
d, earth persons could travel through
Sc 40 minutes.