The Atlanta constitution. [volume] (Atlanta, Ga.) 1885-19??, 1896-02-17

experiments. The apparatus which | en-
ployed was essentially a Tesla coil The
current from the street service ordinarily
used for lighting the building was led in.
! 10 the laboratory and was then transform
| ed from a thousand voltage to sixty volts
| III was then. by means of what Is called a
| Step-up transformer. exalted to perhaps
| $4,000 volts. This would produce a power
| ful spark by means of Leyden Jars of
| perhaps an inch. This spark was formed
between the poles of n horseshoe magnet
ana was blown out by means OF this mag
| net. The current which excited the spark
| was then transformed by means OF a Tesla
/ col TO still higher voltage, and Crookes
tube was placed between the terminals
of the Tesla coil. Several types of Crookes
tubes were employed.
The Most Satisfactory Form.
The most satisfactory form consisted OF
spherical bulb inclosing an aluminium
plate which served for the cathode and
which sent forth the parallel bundle of
cathode rays. The Crookes tubes Of a
concave aluminium mirror. bringing the
cathode rays to a focus on the walls of
the vessel ! did not find so satisfactory as
the tube have just described In the
former the cathode rays proceeded from
a nat plate of aluminium in a parallel
bundle OF rays. 1t was evident to my
mind that the Crookcs tubes which We
now employ to produce these effects are
very Inadequate; that they are rot de-
signed TO stand the sufficiently powerful
eNcitation in order TO set the best effects
from the cathode rays
Bundle of Parallel Rays.
with the Tesla coil it was unsafe to ex-
cite the tubes longer than - minute on ac-
count of the great heat developed. il Il
tube could be constructed Of largest size
with large sheet Of say fourteen inches
square of aluminium for the cathode and
a window Of aluminium to allow the bundle
OF parable! rays to pass ont uninpoded,
as they now are by the glass, much better
results, | think. could be obtained. All
the forms of Crookes tubes now in general
use have cathode terminals that are
small, comparatively speaking. The rays
emanate therefore, from what may he
considered almost point and throw diff !
fused shadows, much like those cast by a I
candle. whereas, If they passed out from |
a large surface in Il parallel bundle Of /
rays one might expect to have much more /
sharply defined images.
The future development of this subject
seems to be in the application of greater
ik;l to tho construction of the Crookes
ubes.
Reports Exaggerated.
Considering the important bearing OF
his subject upon surgery it would seem
o be highly desirable to construct larger
ubes which would be able to withstand
or a long time currents that are sufficient
= powerful TO produce the intense cathode
avs which would be necessary to pene-
rate the human body. Reports which
ave come from abroad in regard TO pho
Osraphing through the human body seem I
D be somewhat exaggerated, because il I
stated that the rays pass through the
esh unimpeded and are only Intercepted |
Y the bones. Ia my own experiments
o not find thisto be entirely true The
esh seems TO absorb the rays, but to a
sser degree than the bones II is Ger
liniy true that the cathode RAYS afford !
lie only means at present of obtaining a ,
presentation of the bones through the +
ssh. have, 50 far. only succeeded IN ,
curing this representation with the hui :
an hand but / propose before long to ,
y TO pass the rays through The entire /,
'dy. TO do this, | have said, will re-
ire much longer exposure and more =,
,werful currents. !
An Earlier Experiment. 4
What 1 am trying now 70 DO as to see =
these cathode rays can he detected in an u
binary electric spark. There is 4 very T.
eng heat emitted from these rays. hur e
,,,b+ ~ j focus by the mirror. IT tAty
y s.rt o,it bv a fiat plate there is not j.
:. hoat developed. MS they are not To-
ed Unfortunately the Crookea tu''s
In now obliged 10 use are very -mPeiie'I
this purpose. They Would pe tnuen oe.-
. # thrv we're provided with az ahumi- O
I'm window.
professor wright's Experiment.
~. ,,,,.assfil experiments Of Professor
". Wright. who occupies the char OF c
,arimeptaI physics at Yale university, s
.ye amazed the scientists OF ne A! ..i '
,tcs The JoUrna! has secured lLuli /
an, his best plate. which is rcprod4itgs@td
.rtr,iin. Ii was made under many dhi'-
Iltirs. but it IS a complete success. .au
professor Wright has been NJ work ever
- IN first news of Professor itoent-
..'s discovery was published in this paper
me weeks ago. -,
ado with a great variety Of substances,
nj IL was found that strong impress, onS
ere obtained upon a Photographic iNa'c