Free trader-journal. (Ottawa, Ill.) 1916-1920, 1918-03-21
DEVICE MEASURES
HEAT Of STARS
LATEST MACHINE HAS MOST
DELICATE THERMo slEc-
TRIO BATTERY
Extensive Experiments are Conducted
BY U. 5. Officials


electric battery ever constructed =
that used by the W. W. Cobientze, .
physicist OF the United States bureau
II standards, in the radiation pyfo-
meter with which he has succeeded
in measuring the heat thar reaches
the earth from H. celestial bodies
Guiding los stars. These measure.
nents are the first extensive serie 5
of the kind ever made, and the wotk
was done by sir. Coblenlze in the Lick
observatory at Mount HamiltoR. Cal.
list summer As an example OF the
ARount of heat that the earth receives
from the stars, Mr.. Coblentze est.
mated that il the rays of Polsris, or
the North Star, were focused upon =
gramme of water it would require
900 900 years for the temperature Of
ihe water 10 be raised one degree
centigrade. The suns rays will accom-
riish the same work in about one min
Ute.
The distinctive .thin- about the ~
r1meter devised by Mr.. Coblent2e is
is extreme delicacy. which makes It
sensitive to change in temperature
OF a mllllonth of degree. With the
aid OF three foot reflector. his IN
strument will register he presence
Of a candle fifty two miles away.
The vital part of the instrument is
thermal battery made by joining
two wires Of different metals-either
platinum and silver or bismuth and
slyer--and covering the junction with
heat absorbing surface painted with
lamp black. The wire used IL so line
that il can scarcely be seen without
the aid of reading glass. and The alb
sorbing surface is about the size Of
q pinhead.
This battery is incosed in a glass
cell with window o. flOurite.
vacuum is maintained in the cell. and
Il is placed in a telescope so that the
lieht of the star 10 be observed is TO
C,lsed upon tie flourite window.
The tiny battery or thermo couple,
Is connected with tangent salyano-
meter which Is inclosed in an armor
cf soft Swedish iron 70 protect ii from
.xtraneous magnetic influence Thus
'he amount OF current generated in
The thermo couple by the heat of the
S.ar is measured by the galsanometes
Within the calvanometer. mirror
smaller than pinhead is suspended
upon fine thread Of spun quartz.
Some distance from the front OF the
window in the ealvanometer scale
IL set up with a strong light upon 1t.
This scale is reflected In the it'll
mirror, which is observed through
microscope There is tiny dot upoa
enc side OF the face Of the mirror.
The generation of current in the
thermo couple causes The quart
thread to twist, turning tho mirror
from side 10 side, and this DETECTION
is measured upon the reflected imaae
al the scale.
De. Edmund Otis Hovey of The Amer
lean Museum OF Natural History has
recently returned to New York aftei
completing the first expedition under
taken with the aid Of the Hei,prin ey
ptoration fund established last wear
IL memory Of Anglo Heilprin, III view
Ct the late Prof. Hielprin's well knows
work in connection with the eruption
OF Mount pelee, it was especially ap
pFopriate that the first work under
the fund should have been an exami-
ration Of The active volcauss of tue
i.esser Antilles. Dr. Hoyev visited
Caudeloupe, Martinique and ST. Vim.
Ceat
IN the American Museum Journal
10 reports the present condition OF
the famous volcanoes in those islandv
Fom the cone OF Mount Pelee cor
siderable steam is. still issuing,
though much less in volume and lowe
In temperature than al the time OF nr.
Hoyey's previous visit in 1903. Tho
activity OF the volcano has steadl}
diminished since the eruptons o.
l9O2'03, and apparently there is no
present danger Of recrudesence. On
ne windward side of the volcano new
vegetation has fully established itself.
and even the forest is being renewed.
The famous spine or obelisk, which
once rose more than coo feet above
the cone, disappeared nearly zen years
sso. One The site of the ruined eit{
Vt 81. Pierre there are 50 new bnild.
iiss and two hundred people.
Successful attempts have recent,
been made 70 manufacture a substi
,ite for rubber tubing out cf maSse
q solidified glue. These tubes, wnoso
trade name is "Sonjatan," are ever
better han those of mbbe, fol Ger
tam purposes according To Technical
Monatsheie, since they are more IN
rel'ious 10 gases and more resistan.
10 heat. 1t is also claimed ,het they do
not grow rotten so quickly as rubber.
and that when increased in suitable
envelope they viii Withstand hi.h
pressure.
Moreover they are very cnesp gas
'ubes OF the new material COSTING ont
50 p.ennig per meter. The inventor IA
Prof J. Taube aud he states that they
are peculiarly suited for conductor
~ petroleum and gasoline as well n.
Eases However they are attacked nv