The Wheeling daily intelligencer. [volume] (Wheeling, W. Va.) 1865-1903, 1896-03-14
K RAYS EXPERIMENTS
Al ihe Lehigh unlyerslty-some Interr,

NJ -----tfttAtta
ing Results.
Brown and White. published at the
Lehigh University. Pa, has the follow
ing:
During the past ten days experiments
on Roentgen's rays have been made in
the electrical laboratory of Lehlgh nni-
versity under the direction OF Dr.. Alex
ander Macfarlane. with the assistance S
OF Instructors Klincls, Webb and Clark.
The object has been to test the physical
properties of the rays. The Grookes'
tube, used In connection with an in-
duction coll. Is a cylinder 10 inches long
and 1 n inches in diameter, with a metal
disc In the middle to form a cathode,
and a wire at each end TO form an anode.
When the two anodes are Joined to the
coil, there is q dark space on each side
of the cathode. and both ends Of the
tube are tiuorescent; when only one
tube fiuoresces. To test the manner In
which the Roentgen rays are propagnt-
ed from the tube, the following expert
ments were made; Thin nails one Inch
long were driven vertically into half
inch block of wood SO as to form regular
rows and columns, and they were all
driven In so that their points just
pierced through the wood. The block OF
wood with the nails was laid on plate
holder and placed at the end Of the
Crookes' tube so as to be perpendicular
to the axis Of the tube. AS result the
Photographic plate showed single
shadow for each nail; right opposite
the axis of the tube mere dot, but out
from the axis the shadows are like
comets, the further out the longer the
tails, and all these comets point straight
at the dot in the centre. The dot In the
centre may be compared, +, what astron-
omers call radiant point IN a meteorlc
shower: but here the mGieors are all
heading towards. not from It. The d.
rection OF the rays Mt the side OF the tube
was next investigated. When the block
with the nails was placed in vertical
position alongside the tube and both
anodes connected with the coll. each
nail produced two shadowsi opposite the
cathode the shadows were equal, to-
wards each end of the tube they were
unequal. The two systems Of shadows
indicate clearly that the rays do not
radiate from the tube as a whole, but
that they radlate only from the ends,
where also the fluorescence is. When
one anode Is connected only one system
of shadows is obtained.
The examination of the two shadows
VI q RA0duNGNf WITCH TIC nan 10 bG-
tween two excited ends shows how the
exact location of the nail may be re-
duced. The point of the nail as sepa-
rated by the slide from the sensitized
surface; consequently the two shadows
do not meet; but II they are prolonged
the point of Intersection gives the true
position OF the nail. This indicates how
best to use two radiate sources when u
seach for the location Of bullet or q
needle in flesh Is made.
In some published results experiment
tiers have been puzzled by obtaining
double shadowgraphs OF an object. The
reason is that their plate was probably
exposed to two distinct centres Of radia-
ton. To test whether the Roentgen
rays are retracted needle was placed
partly over a prism and partly In the
air; the two parts of the shadow were in
one straight line. showing that the rays
through the prism were not bent from
their original source. The double
images which some experimenters have
got from rays passing through Iceland
spar were probably due to the radiation
coming from two distinct centres.
The reflection of the rays was tested
by placing the block of nails where the
direct rays could not strike them. but
the rays reflected from a metal plate
would IL these rays existed. The photo
graphic plate showed no impression. 1t
was found that a red-hot iron wire was
as Opaque as a cold iron wire.
The experiments show that the Roent-
gen rays are promulgated In straight
lines from the surface of the glass where
the cathode rays strike, and that, as
Roentgen concluded, they are neither
reflected nor refracted.