The San Francisco call., 1896-04-27
CATHODE RAY EXTENSION
It Now Beams Brightly in the
Cogswell Polytechnic
College.
What Principal Buchanan Expects
to Discover With His Home
Made Machines.

The latest thing to be penetrated by the
all-see1ng cathode rays, discovered by Pro-
fessor Roentgen, is the Cogswell Poly
technic College. An electrical machine of
wood, glass and metal has just been con-
structed there, and students and teachers
will soon be deeply absorbed in scientific
experiments to test the intensity and
penetrability of the wonderful X rays.
'It is our intention" said Principal l..
A. Buchanan, "to keep abreast of the
times, so far at least as our rather limited
means and equipments will permit, and,
of course, the recent great discovery of
Professor Roentgen cannot be ignored.
With this idea had our students con-
struct, during the late holidays. sixteen
inch plate Wimshurst machine, which
will be operated by a small electro motor.
Besides the cathode-ray experiments, this
machine can be used for class illustration
purposes in other studies. The boys were
much interested in the making of it, and
by our labor We have saved some SIS on its
cost.
"Our induction coil lacks the proper
sparkling capacity. 1t is a fine instrument
for class uses, but gives spark OF only
about one inch with all the battery l dare
connect to it. With this and after long
exposure we have produced a number of
plates of coins and glass and metals
tested for their density. Within month
we expect to have bigger machine of the
Wimshurst type completed and in opera
ton, also another induction coil capable
of giving @ five or six incn spark and
pump, so that we can then give clear
demonstration and observe every detail of
the phenomenon. We shall in this way
be entitled to secure the attention of our
stud ents, to hold their interest and to
teach them the best methods off original
Investigation, as well as give them some
practical ideas of mechanical designs and
construction"
What will be the immediate results of
your experiments?"
"Well, OF course, that is difficult to
state precisely, but when I've concluded
the series of experiments l have now in
my mind | trust that, aside from their
educational benefit to the students, we
shall possess better knowledge of the
law of the intensities of the cathode rays
and OF the relation existing between the
energy required and the intensities. /
found by experiment with a radiometer
that it was hardly affected by the rays.
This may be i'll consequence of the impene-
trability of glass. The calorifc effect upon
a sensitive thermoscope is also an inter
esting experiment, while the result, COM
ing from magnetic disturbances is peculiar
and an investigation may lead to the dis
covery of new and surprising truths.
"All of the phenomena tend to the study
OF the rarer ether end will probably aid
materially in solving the molecular and
atomic structure of all things, especially
Of light, magnetism and the undulatory
theory connected with it.
professor Roentgen, in the course of
his numerous experiments, finds that the
transmission of the rays is affected in
some degree by the density of bodies The
retina of the eye, he says. is not affected
by the rays and no calorific effect has as
yet been noted. The cathode ray thus far
has perhaps been of the greatest practical
benefit in surgery, but the possibilities of
its DEVELOPMENT are almost limitIess and it
Will soon, think, be used to equally great
advantage in the industrial world to test
the materials employed in engineering,
etc."