The Virginia enterprise. [volume] (Virginia, St. Louis County, Minn.) 1893-19??, 1896-03-20
A QUEER EXHIBITION.
Flying Machines, Kites and Aeroplanes
Shown in Boston.

Shown in Boston.
There will be !: Unique gathering of
more or less visionary modern disciples
of Darius Green ar Boston next October.
There is to he held during that month a
grand competitive exhibition of designs
for and working models Of airships, fly
ing machines and aeroplaneS, under the
auspices of the Boston Aeroplane ;tsso-
citation.
Five valuable cash prizes. the amounts
of which will be made public May |, as
contributions to that end, are being So
Ecited from the scientific men Of the
country, will be awarded as follows:
For the kite showing the maximum
of lift to the minimum of drift in a
breeze having a velocity of more than
hfteen miles per hour
For the kite showing the maximum of
lift I" the minimum of drift in 4 breeze
having a velocity of less than fifteen
miles all hour
For the kite keeping its equilibrium
through the greatest extremes of wind
velocity.
For the soaring machine in free flight,
which, after gaining velocity. shall make
the best course. the excellence IF the
course to he Judged by the maximum of
length and the minimum of undulation.
Energy may be given to the machine by
CARRYING it to height.
For the best clfpropelled machine.
Rocntgen's Discovery.
During the last week innumerable re-
ports Of work in y ray photography have
appeared in the columns of the various
journals. scientific and otherwise. but
with comparatively little new matter in
them. 1t still appears that Prof Roent-
gen gave the matter so thorough Il treat
mrnt before publishing his results that it
has taken the rest of the scientific" world
a month to catch up with him. It is said
that photographs taken by him are better
than the. majority of those taken by 9th
or experimentcrs. His modest paper on
the subject of his discovery has not
been exceeded in interest, clcarness of
statement. and precision of deductions,
by. all which has been published since.
Prof. Roentgen's discovery is shown
to have been developed from experiments
face he found was rendered luminous by
the \ rays fter they had passed through
an opaque screen. To so from a phos-
phorescent surface to the sensitized pho
tosraphic plate was quite natural. Now
we hear Of an invcStiga tor retra cling this
step and returning to the phosphorescent
plate with the most interesting results.
Prof. Salvioni of Perugia on Saturday,
February $, read Il paper before the
Rome Medical society. describing an ao-
paratus Of his own invention which en-
ables the eye to see the Roentgen cf-
| feet. AS imperfectly described in a ca
BILE from Rome, tube is employed and
the shadow produced by the X rays
| is cast upon Il fluorcscent surface, the
object to be examined having been
| placed between the observation tube and
| the Crookes tube. \ perfect shadow is
thus procured. and the outer end of the
tube is provided with lens by which
| the image may be intensified for pur-
poses Of examination. 1t is a snbstitu-
ton Of the retila of the eye for the pho
| tographic surface, with this difference,
that to produce avisible effect the Roent-
gen rays have first to produce true light
rays. This they are made to do by II
fiuorescent surface. 1t will be seen that
! this is merely a reproduction and devel-
! opMcnt of Roentgen's first experiments.
| Tor II the rays can render Il !luOrescent
surface luminous. the possibility of the
! production of shadows u9on such a sur
! face almost necessarily follows Prof
Salvl"ni calls his highly Interesting appa-
ratus the cryptoscopc. When the stcti,o-
scope was first invented. it was hailed
i as Il great achievement in revealing to
| the auscultator the secrets of the opera
| tons of the human system. But if the
| cryptrScopc can be sufficiently tlevcl-
! oDed it will place a more powerful i'll
| Strum"nt Of research in the physician s
| hands. by which he will he able to see
! the shadows Of the bony framework
of the animal system without an appeal
to photography Americana