Evening star., 1927-04-26

order to produce an effect at the other
end Of the wire.
The problem would have been some.
what simpler IL continued bright
light could have been allowed to shine
on the object, but in the case of a
human being this would have been
binding. Consequently, the idea of
small spot of light continually NOV
ing over the features was worked out.
This spot moves so rapidly that it has
the effect, so far as the sitter is con-
cerned, of weak continued light and
causes no discomfort whatever.
The operation involves the sending
| of approximately 10000 changes of
| current second.
In concluding his lecture DR.. Ives
said that the inventors of television
had no conception of what it's future
| Of practical use would be, but, al
| though employees of a great CONNER
! cial concern. found their reward in
| the faith common to all scientists
| that no increase of human knowledge
| is without eventual usefulness.
| DIR. Frank b. Jewett, president of
| the Bell Laboratories, where televi-
sion was perfected, preceded DIR. Ives
and spoke of the other great accom-
| plishment of the company during the
present year--the establishment of
regular telephone communication be-
tween the United States and England.
Interocean Telephoning Cited.
Interocean Telephone communica-
ton has been possible for the past
10 years. DR.. Jewett said and the
intensive research work in the in
terval has been to turn a possibility
into a practical thing. The weak
link, he said, was the necessity of
using radio for transmission across
the Atlantic with all the attendant
uncertainties. If the world could be
girdled with land lines, he said, 1t
would be possible to send the human
voice several times around the globe
without any sensible diminution.
The difficulties of working out a
practical system, DR.. Jewett said,
were not all physical, but involved
the training of personal and synchron-
ization of the telephone systems of
the United States and Great Britain.
He said that while the present system
extended only to Great Britain, it
was only a matter of time before
anybody in the United States with a
telephone could call up anybody on
the European continent owning a
telephone.
Within the past two years, DR.,
Jewett said, there have been three
revolutionary developments in COM
munication. The first of these was
the construction of cable lines of a
new alloy which enabled them to
carry six or seven times as much
traffic as previously. The others have
been the transmission of pictures,
transoceanic telephony and television.
Papers on Physical Sciences Read.
The session yesterday afternoon was
devoted to the physical sciences. with
papers by some of the principle fig
ures in that field.
DIR. Paul II. Heyl. head of the divi-
sion of sounds at the Bureau of Stand
ards. told of the recent completion
of his work of reweighing the earth
or rather of checking up on the grav-
itational constant of Sir Isaac Newton.
The law of gravitatiou as stated by
Newton says that any two masses of
matter attract each other by a force
directly proportional to their masses
and inversely proportional to their
distance apart The exact force is
found by multiplying the masses,
dividing by the distance and then
multiplying the result by the gravi-
rational constant. This constant must
be known very precisely in physical
experiments, and DIR. Heyl has calcu-
ated little more finely than ever be-
fore. He has found 1t 70 be the frac-
tion 6.664 over 00,000.0 900.
Earlier methods of determining this
constant consisted of hanging a plumb
bob beside a mountain. the weight of
which was guessed at, and measuring
the detection from the vertical, de-
teErri2e6 by observations Of the fixed
stars.
Employs Improved Method.
D-. 5svz nsad En- improvement on
the SyEe- br which rM0 tiny masses
ara attached nc -hs end Ct a rod which
is ha2aDcaG AT THE end of q long wire.
Two heavy spheres Of lead near the
ends o9 tas rod pull on the little
masses and twist the wire slightly.
This twist can be measured BY
little mirror attached the the wire,
which reflects a spot Of light across
the room, small twist producing a
much larger motion Of the light spot.
Much the same experiment was made
in 1901 by DIR. George X. Burgess,
now director Of the Bureau Of Stand
ards, at the Sorbonne in Paris, but
he was not satisfied with the result
and when he became director of the
bureau saw to It that the experiment
was performed more accurately.
Light and Heat Radiation.
Dr. Charles c. Abbot, acting director
of the Smithsonian Institution told of
what seems to be the solution OF the
problem Of how light and heat radiated
from the sun vary. While it has been
known for nearly century that the
sun undergoes an 11-year cycle. dur
ing which the sunspots wax and wane,
and that the intensity of the radiation
is somewhat proportional, the cor
respondence has not been close enough
to permit advance predictions of what
the radiation will be. DIR. Abbot took
values for the intensity Of solar radia-
tion for II months, ending last Octo-
ber, and these were analyzed by DIR.
Dayton c. Miller Of the Chase School
of Applied Sciences at Cleveland by
an ingenious machine known as the
harmonic analyzing machine.
The results show that there is a
marked period of about % % months
and two others less strongly marked
Of Is 2-5 months and II months. It
already has been found that the
worlds rainfall average undergoes a
variation of Is rs months and other
weather variations may be found to
correspond with the sunspot yaria-
tions.
Describes Moons Surface.
The studies Of DR. f. r. Wright of
the Geophysical Laboratory of the
Carnegie Institution of Washington,
which he described, Indicate that the
surface cf the moon consists of such
rock as pumice and granite with no
basalt. And as basalt is almost In
variably associated with volcanic ac-
tivity as far as is known, this is
rather a jolt to the theory that the
moon was once the scene of vast vol
canic activity, producing the craters
that are susl familiar feature of
its cIIrfanp