Boxoffice-March.04.1950

!
RECTIFIERS
Fnr EvTT Siz9 Thcatrm
• TYPE LD-90-50 to 90"amps-
• TYPE LD-75-AO lo 7 5 amps.
• LD-60 BULB TYPE - AO lo 60 amps.
• LD-30 BULB TYPE- 30 amps.
• SELENIUM and MAGNESIUM COPPER
SULPHIDE RECTIFIERS up lo 90 amps.
FOREST- HARRISON,
INC.
207 Railroad Avenue Harrison, N. J.
TRY IT
THE
IDEAL All-Purpose
Theater Cleaner
VACUUMS! \
THAN A POPCORN BLOWER \
tK9^^
•"'
-£ THAN A VACUUM CLEANER 1
l*" —DOES EVERY KIND OF /
THEATRE CLEANING! /
Gets rid of floor litter in 1/3 the time of
sweeping . simply blows it to the front of
. .
the theatre where it is easy to scoop up . . .
blows dust and dirt from amplifiers, projectors,
lights, decorations . . vacuums carpets,
draperies, ledges, grills . . . sprays deodorants,
moth preventives, insecticides. Keeps entire
theatre sparkling clean at a fraction the cost of
other methods. Easy to use. Weighs just 91/2
lbs. Full 2/3 horsepower.
Sold Through Amer ca's Leading Distributors
'
MAIL
COUPON
TODAY
THIS COMPLETE \
POPCORN BLOWING I
KIT FOR THE PRICE OF A /
HOUSEHOLD VACUUM CLEANER /
IDEAL INDUSTRIES, Inc.
5225 Park Avenue
FREE DEMONSTRATION .
()D£Ar)
. . Pleaie arrange
for free demonstration of IDEAL
Theatre Cleaner ond send folder.
NAME
ZONE
STATE
NEW RCA PROJECTOR HAS
FOUR-INCH LENS MOUNT
A new 35mm projector of radically
advanced design was announced recently
by the theatre equipment section of the
RCA engineering products department.
Innovations in the new "RCA 100" projector
offer marked time savings and new
standards of operating safety and convenience,
RCA asserted.
Describing the new projector as the
finest ever turned out by the Brenkert
Light Projection Co., Karl Brenkert, president
of the RCA subsidiary, stated that
it retains the established Brenkert features
of rock-steady projection, highly efficient
delivery of light to the screen, and
low cost of maintenance.
Nylon rollers, large, full-view glass windows
in both the film and gear compartments,
shielded interior lighting, and a new
lens mount are among the new features
of the "RCA 100."
The use of nylon rollers eliminates the
need for lubricants in the film compartment,
removing any possibility of oil damage
to the film.
A glass door on the film side enables
the operator to observe the entire film
path continually while the projector is in
operation.
Soft interior lighting, shielded from the
operator's eyes, increases the ease of
threading film and cleaning the mechanism.
An illuminated gear compartment and
an unusually large glass-covered aperture
in the housing of the compartment make
it easy to check at any time the operation
of the gear train and the lubricating
system.
The lens mount of the new projector is
designed to accommodate the new fourinch
high-speed projection lenses, which
provide edge-to-edge sharpness over the
entire screen surface, thus eliminating socalled
"hot spot." The mount holds the
lens firmly at both front and rear, so that
perfect optical alignment is assured for a
lens of any focal length.
The automatic lubrication system which
has been a standard feature of Brenkert
projectors for more than ten years is retained
in the new model. All rotating
shafts running through the main case
casting are equipped with oil baffles, so
that shaft bearings are continually lubricated
throughout their length, but no
oil can leak into the operating compartment.
The sturdy intermittent mechanism and
heavy-duty gearing of the Brenkert BX 80
projectors are also retained in the new
projector.
Industrial Photography
Of Growing Importance
Photography in industry accounts for
more than two-thirds of the photographic
materials used today, William P. Swann, a
member of Eastman Kodak Co.'s industrial
sales division, reported recently. The other
third is used by amateur photographers.
The ability of an ordinary camera and
camera technique to estimate the volume
of pulpwood in stock piles is an unusual
industrial use cited by Swann.
By using a high contrast photographic
material, a flatcar full of wood is photographed.
Spaces between the logs are produced
as black areas. The faces of the
logs become white areas. A special photoelectric
scanning machine is then used to
evaluate the amount of light areas to the
dark areas and, assuming the length of the
logs to be standard, an accurate estimate
of the total volume of wood can be obtained.
A relatively new instrument, the electron
microscope, is capable of magnifications up
to about 20,000 times. Used in conjunction
with photography, it has important uses In
connection with studies of abrasive materials,
chemicals, plastics and structures of
metals.
34 The MODERN THEATRE SECTION