The true northerner. [volume] (Paw Paw, Mich.) 1855-1920, 1878-07-19
sOIENTiFIC WONDERS.

From the New York He-adl
The latest marvel from Menlo Park il
the tasimeter," or instrument for the
measurement of pressure, which Prof
Edison has just completed. 1t is to be
used in the scientific experiments to bt
made by astronomers from all parts ol
the world at Denver, Col, next month
during the total eclipse of the sun, Wis
ible at that place. Prof. Edison starts
for that State on the 9Th OF July, &C
companied by Profs. Draper, Barker
and other scientists from this section OF
the country. The results thus far OBJ.
tanned from the tasimeter have been al
most incredible. Used in connection
with the galvanometer of Sir William
Thompson, it has been found to record
the pressure of INSTRUMENTATION
sandth part of an inch.
Hitherto the most delicate instrument
known to science for determining the
heat in the different parts of the solar
spectrum has been the thermopile. The
great improvement of the tasimeter
over the thermopile is illustrated in a
simple manner by Prof. Edison. A
few inches from the former he placed a
hot iron. 1t DETECTED the needle of an
ordinary galvanometer one degree then
he held his little finger four inches from
the tasimeter with the same galvanome-
ter, and it swung the needle around six
degrees. In explaining the workings OF
his new invention to a Herdid reporter
in his laboratory at Menlo Park, yester-
day. the inventor said 1--WE now study
chemistry by means of the sun. We
have found by the aid of the spectre
scope that there are metals in the sun
which are unknown on earth, as well as
metals here the existence of which In
the sun have thus far not been discov-.
cred"
CURIOUS EXPERIMENTS.
The professor then made a number of
curious experiments. "See here" said
he, taking up thin strip of vulcanized
rubber and placing it between two small
upright iron posts in the tasimeter, "this
is highly sensitive to heat-alittle causes
it to expand. At this end 1 place my
carbon. l found out that silk coated
with conducting lampblack, pressed in
the form of button, was wonderfully
sensitive to the passage of the electric
current. Put upon it the pressure of
one-half millionth of an inch and it will
allow the passage OF a current strong
enough to defect Sir William Thomp-
sons galvanometer one degree. OF
course, greater pressure defects the
needle more" Prof. Edison then took
an ordinary galvanometer and put it in
electric circuit with his tasim eter and
held his hand four inches away from the
vulcanite strip. Instantly the needle of
the galvanometer moved five degrees.
Next he lighted gas jet five feet away,
and the needle moved four degrees.
Then he held a match distance of six
inches and the heat indicated eleven de-
gres in the galvanometer. Breathing
ficiently to mark thirty degrees. These
results the professor produced without
the improved galvanOmeter, which he
explained was infinitely more sensitive.
MEASURING MOISTURE.
Prof. Edison next introduced between
the posts slip of gelatine, in order to
measure moisture. Moistening piece
of paper slightly with his tongue, he
held it three inches away. The defec-
ton was eight degrees. A breath on the
gelatine moved the pointer thirty five
degrees. A drop of water on the end of
his finger, held five inches away, indi-
Gated a moisture of eleven degrees. A |
lighted cigar, at a distance of nearly |
q foot, dried the atmosphere sufficiently !
to cause detection of seven degrees. |
Water in bottle held near by made the |
needle vibrate.
THE ECLIPSE OF THE SUN.
The professor next explained the |
method proposed to be adopted in the
experiments to be made
with his tasimeter. Instead of vulcan
lied rubber, platina will be used, the
latter having been found to gain and
lose heat much more readily than the
former. The tasimeter, unlike the one
on as above, is to be
smaller and of different material, brass
only being used throughout. It will be
inclosed in receptacle of tin, which, in
turn, is placed in a second receptacle of
the same metal. Between the two will
be kept boiling water for the purpose of
evenness of temperature, as
boiling water attains no higher tempera-
ture than 2l2 deg. Fahrenheit. The
spectroscope will then be made to con-
centrate the heat into a small open
ing in the tasimeter, where, falling on
The platina, it will cause expansion and
pressure of the small car
bon button, allowing the passage of the
electric current in degree common
surate with the pressure. Attached to,
and forming part of, the tasimeter, is an
appliance for measuring the degree of
or contraction of different
metals under similar temperatures.
Prof. Edison found that the heat of his
hand expanded the platina one FIVE
thousandth part of an inch.
1CEBERGs MADE HARMLESS.
The great inventor has already taken
steps to use his new discovery for the
protection of vessels at sea. He stated
to the writer his method, as follows "I
arrange the carbon button as highly
barometer, aud, inclosing it in
a case, connect it with the keel of a
ship. 1 then run a wire to the Captains
room into an ordinary galvanometer.
Any change of temperature, as you see,
is at once indicated. Goodness of the
water will contract and warmth expand.
and the corresponding reflections be
placed at once before the eye of the
Captain. The approach of an iceberg