Using the “Electric Eye“ to Destroy
Electric eyes" now am
man in his war upon
insects. This device,
which is a photo-electric cell, is
installed in orchards to turn on
electrically lighted insect traps at
Insect Pests
dusk ami turn them off Ht dawn.
The electric eye is entirely automatic
?n its operation. When the light in
tensity in the orchard falls below lf>
foot-candles, the photo-electric cell closes
a switch which turns on ail the light
traps. When the light intensity rises
above 90 foot-candles it opens the switch,
turning off the lights.
A time-clock device would be satis
factory if dusk arrived on a time sched
ule. but light clouds cause dusk to arrive
a little earlier and heavy clouds much
earlier.
The electric eye is claimed to be the
only known device which will automati
cally recognize the approach of dusk and
turn on the lighted insect traps.
The photo-electric cell also eliminates
the human factor. It is exceedingly diffi
cult for an attendant accurately to judge
the fast-changing shades of afternoon
light as it fades into darkness. Yet it is
of particular importance that the light
ed traps be turned on at the right time,
because investigations have shown that
moths begin to fly and to lay eggs about
20 minutes before sunset.
Twelve acres of an apple orchard were
illuminated as if for a garden party in
this experiment, which is one of the out
standing scientific projects of its kind.
Moths arc the marauding invaders
that play havoc with fruit. The method
employed against the moths is to attract
them by means of electrically lighted
traps located in the foliage of the trees.
In one kind of trap they are caught in
water pans under light. In another they
are electrocuted as they come in con
tact with high voltage wires which sur
round the source of light. Every time
a buzz is heard, another moth has sizzled
to destruction.
The experiments in destroying insect
pests have been in progress since 1929,
under the direction of Dr. P. J. Parrott,
assistant director of the New York State
Experimental Station at Geneva, New
York. Already sufficient progress has
been made to justify continuing the in
vestigations which may lead to a more
general use of light for trapping insects.
Experiments over a four-year period
How Bugs That
Devour Crops
Are Now Lured
to Death by
Electrocution.
in a certain plot indicate that this reduc
tion in injury may be of a cumulative
type, that in, that year by year the cod
dling moth infestation is diminished
from the degree of the previous year.
E. H. Vedder, a Westinghouse engi
neer, points out that the entry of the
"electric eye” into the field of insect
extermination is but another use added
to the rapidly growing total that are
common to every day life. Offices and
factories use it m counting and sorting
operations. Industries and stores use it
to match objects and materials for color.
In ultra-modern drinking fountains,
the “electric eye” turns on the water as
h person stoops to drink. In buildings
and warehouses, it prevents elevator
doors from closing on passengers and
warns of fires. In smart restaurants, it
causes doors to open in front of bur
dened waiters. For the up-to-the-minute
suburbanite, it opens the garage door
as he puts the car away for the night.
There is no escape from the “electric
eye,” for the walls of prisons are now
guarded by this wide-awake device.
With photo-electric cells properly in
stalled for this purpose it is impossible
for a prisoner to attempt to scale a wall
without setting off an alarm.
To demonstrate just how the electric
eye foils all attempts at escape a prison
wall in miniature, 16 feet long and nino
The Biggest Belt in the World
W~MMT
This Hn|f Brit Which Weigh* 31 *4 Ton* 1* One and Three-fourth* Inches Thick.
It Is Used on a Conveyor Capable of Handling About 2,000 Ton* an Hour and Was
Made in Three Sections, Each of Which Weighs 21,000 Pounds.
WHEN a limestone company found
it necessary to increase tne han
dling of their product to 1,950
tons an hour they required for that pur
pose what is claimed to be the biggest
belt in the world.
This belt, which is shown in accom
oanying illustration, was made in three
sections, each weighing 21,000 pounds.
This makes the total weight of the en
tire belt amount to 31% tons.
The belt is 64 inches wide and one
and three-fourths inches thick. It was
designed for use on a conveyor 700 feet
long and is capable of handling about
2,000 tons an hour.
HowSun-SpotsMay Be Formed
A SIMPLE experiment made with
a special device constructed by
a European physicist named
liiabouchinsky, may offer a solution of
the secret of now sun-spots are formed.
The sun, astronomers have found, is
not a solid sphere. It does not consist
of liquids even, but gases. Observations
iJttr
voMt *
GLOOt
FULL OF
watch
I—■
show that the period of the sun’s rota
tion at the surface is not uniform.
Magnetic researches detailed by Dr.
Ross Gunn, of the United States Naval
Observatory, conclude that the sun, as u
body rotates in 31.8 days; while at its
surface the rotation takes place in be
tween 24.5 and 26.7 days.
■ ltiabouchinsky
VVUOV1 UVMiU BU **}>•
paratus in which a
propeller is re
volved in a glass
vessel full of water.
When the vessel
stands still, a vor
tex is formed (Fig.
1); but when the
vessel itself is also
turned at a differ
ent rate, eddies
reach the surface
of the glass and
form spots on them.
Figure 1. The Wa
ter-tilled Globe I*
Stationary, as thr
Little Paddle Re
volves, Making an
Eddy. Figure 2.
When Both Globe
and Paddle Are Re
v o 1 v i n g, “Spots”
Are Formed,
feet high was erected. Along this wall
an electric eye watched a beam of light.
An assistant dressed in prison garb
stealthily approached the wall. He at
tempted to climb over. Immediately, as
the beam of light was interrupted the
electric eye came into action. It fired a
gun thereby warning all within hearing
that an escape was imminent. That,
however, was not all.
An iron door was > set into the wall.
Another tube, this one called a "grid
glow,” was guarding the door. The mo
ment a human hand approached this
door, even if it did not quite touch it, a
prison siren started to scream. The wall
and door were automatically and ahso
1
lutely guarded, night and day, by these
electrical products.
This demonstration was especially
rendered to show the ability of these
two tubes to guard walls and doors
against intruders and is another tri
umph of the electrical laboratory. Thus
the electric eye is shown to be even more
efficient for certain purposes than the
human eye.
The electric eye resembles in its ex
ternal appearance a radio vacuum tube.
Originating in research laboratories
long ago, the photo-electric tube was
greatly improved in the impetus given
to tube development by radio following
the World War. In making possible to
Left: The Electric Eye Which Control*
the Eight in a Trap for Exterminating
by Electrocution Moths and Destructive
Bugs That Attack Crops.
Above: Inspecting the Light Trap Which
Electrocutes Moths anil Other Insects.
The Light Within Lures the Unsuspecting
Bugs, Which Die Instantly on Coming in
Contart With the High-Voltage Wires
Around the Light. The Dead Insects Are
Collected in the Pan.
day's talking movies, it achieved its tirst
commercial importance.
An important use of the electric eye
is its application to the stopping of ele
vators, which is a very simple operation.
A small automobile headlight bulb is
mounted upon a control panel on the
side of the car. An “up” controlling
photo-tube is mounted three inches
from, and on a horizontal line with, the
light bulb. Three inches on the oppo
site side, the “down” photo-tube is
----
mounted. When the light’s rays fall
upon the “up” tube the ear moves up
ward and when they illuminate the
“down” tube, the car descends.
The photo-electric cell’s usefulness u
due to its peculiar reaction to light.
When the sensitive, coated-metal cath
ode inside the tube is illuminated by an
outside source, the tube allows an elec
tric current to pass through its circuit.
If the outside source ceases to emit
light or if its rays are interrupted be
fore striking the tube, no current can
pass.
The time-and-bother-saving applica
tions of the electric eye already made
are not a drop in the bucket compared
to the number that will be eventually
in use, engineers predict. The world is
approaching an age wherein many of
man’s actions will be anticipated and
assisted by an electrical or mechanical
servant. The electric eye is bringing
that time nearer day by day.
The Curious Long-Shot Gun
THE man who once was the owner
of the strange, lengthy-barreled
shotgun shown in the accompany
ing illustration, never could truthfully
say that he would not do a thing “by
a long shot,” especially when he went
hunting. He could bag his game only by
a long shot, for his gun was designed
A New Fog-Piercing Headlight for Motor Cars
FOG, terror of night-driving, which
looms as an eerie, misty wall in
front of the motor car headlights,
has yielded to a new amber parallel head*
light, perfected after four years of re
search. The new headlight throws out
and down two narrow rays, each about
two feet in width. These beams, from
75 to 126 feet in length, depending upon
the density of the fog, illuminate the
roadside ahead of the car. Automobiles
have been driven at speeds as high as
85 miles an hour, using the new
lights, through fogs which
otherwise would have slowed
the driver down to five miles
an hour. •
Fog consists of minute water
particles held in suspension.
The action of these particles
upon the white rays of the or
dinary Headlight, is what causes
that impenetrable wall to form
in front of the eyes of motor
drivers. Some of these
.
car
water particles are round, some
tear-shaped. They do all sorts
of things to light rays. They
reflect and refract them, from
particle to particle and break
them up into millions of minute
rays which are sent in every
direction. Some of the particles
act as prisms which split the
white rays into the elemental
bow effect. Part of the rays
reflect back into the eyes of the
drivers so, with all this going
on, it is no wonder that they see
in front of them only a dim,
misty, eerie wall of light. Then
come accidents, all due to the
wall of diffused light that hides
the road from drivers’ eyes.
The new fog-penetrating
beams, however, operate on a
different principle. Two head
lights are used each consisting
of the usual six-volt lamps
and parabolic reflector. They
The Fog-Penetrating Head
light Which Throws Two Am
ber Beams Directly Down the
Side of the Road. The Draw
ing in the Circle Shows How
Two Lights Are Combined
Into One Headlight.
bo that the
lights point to
either side of
the road. In
side the head
light and di
rectly in front
of the lamt>, is
another small
spherical re
flector. This
secondary re
flector is ad
justable and
its purpose is
the radiator, faced away from each other
at aa angle of approximately 30 degrees.
vv txuy ux me uum
passing directly through the lens. In
stead these rays are sent back to the
How Electricity Is Now Made in Vacuum
HUGE disks, spinning at a terrific
speed in a vacuum form a new
method of generating electrical
current which is destined to replace the
familiar drnamo of today, according to
Doctor R. J. Van de Graaff, a physicist
of the Massachusetts Institute of Tech
nology.
Doctor Van de Graaff has achieved
great fame in the scientific world for the
simple but tremendously powerful elec
trostatic machines he has built for pro
ducing Martificia! lightning” which is
measured in hundreds of thousands of
volts and is used in experiments for
breaking up atoms.
Professor Van de Graaff’s atom
smasher consists of two large hollow
columns, twenty-five feet high and six
feet in diameter, surmounted by a hoi
low polisned aluminum sphere fifteen
feet in diameter. The spheres are
charged in an unusual manner, paper
belts, four feet wide, carrying up the
electrical charges sprayed upon them at
the base. In tests, with the generator
discharging close to ten million volts,
scientists are able to work within the
hollow terminals.
Doctor Van de GraafT describes the
spinning disks as enormous electrostatic
machines which are producing direct
current electricity at tremendously high
voltage. The vacuum is necessary, it is
explained, to prevent the production of
tvemendous sparks that might wreck the
whole machine, and would in any case
prevent the electrical current from be
ing led out on wires to be usefully em
ployed.
ausi cjnaiaua, in
parabolic reflector and so, there is per
fect control of the light rays inside the
headlight. There are no stray rays, as
in the usual headlights. It is these strays
which cause the glare in ordinary head
lights no matter how well they are fo
cussed.
The rays pass through the special
amber lens which provide the beam with
its particular characteristics. Each
beam, directed from the fog headlight,
runs out in a straight line from a point
about six feet in front of the wheels to
a point almost 100 feetJigad of the car.
The beam is clean cut on each side and
has about the same intensity through
its length.
to uie anver approacmng n on a eiear
night, the fog-penetrating beam
does not appear as a blaze of
light* as do the usual head
lights, but as two amber paral
lel beams, running along the
side of the road, emanating
from twin amber points on the
approaching car. There is no
glare.
Fog has a tendency to hang
just above the ground. The
effectiveness of the new lights,
it is claimed, lies in their abil
ity to skim under the bottom of
the fog line and to reduce the
effect of the diffusion wall upon
the human eye.
Growing a Potato
Without Starch
DIABETICS who are very fond of
potatoes now may not have to
give up their favorite dish, as
the result of the development of a
starchless “spud,” which has been ac
complished by Doctor Harold Hibbert,
Professor of Industrial and Cellulose
Chemistry at McGill University, and
Doctor R. F. Suit, Professor of Plant
Pathology at MacDonald College.
Doctor Hibbert describes as follows
the method of producing the new potato
in which the starch has been displaced
by a complex sugar called inulin:
“The idea presented itself that per
haps it might be possible to alter a given
plant species by introducing into the
growing plant either the living organ
isms, bacteria, or the enzymes which
these bacteria create.
“We selected for this purpose the
potato plant in which the enzymes (in
the course of plant growth) under the
influence of light convert-the carron di
oxide and water present in the air first
into sugars and then into starch.
“A foreign bacterial culture, which
was more nearly associated with the
inulin type of sugar—forming bacteria,
was introduced into the young, growing
potato plant.
“The culture found its way into the
roots from a supply located on a stout
stem. Within a few days the new bac
teria formed a potato that was starch
less.”
for hunting in the mountains.
This gun, which is one of the most
unusual ever made, is a muzzle-loader,
using powder and ball, the charge being
packed by a ramrod of great length.
The gun weighs 50 pounds, which made
it necessary to fire the weapon while
supported on a rest.
The barrel of this curious gun is 12
feet long, was once the property of a
pioneer of Calaveras County, California.
It was originally used for shooting game
at great distances and its owner is said
to have brought down many an animal
on the opposite side of a wide canyon.
This gun was presented to the Ponj
Express Museum, of Pasadena, Cali
fornia, by W. Parker Lyon who acquired
it from the original owner
m i
An Old Twelve
Foot Gun De
signed for Shoot
ing Game at Great
Distances. It Is a
Muzzle - Loader.
Using Powder and
Ball and Had to
Be Fired While
Supported on a
Best Because of
Its Great Weight.