Theatre Design & Technology - May 1970 - 31

For many years the motion-picture industry
has used high intensity carbon arc illumination to project movies on the screen. Other
light sources either lacked sufficient brightness, desired color, or did not have the
optical characteristics to project the film
satisfactorily. The chief competitor to the
carbon arc has been the tungsten lamp.
However, in the wattages required for screen
brightness the tungsten filament size was
too large to be used efficiently. Consequently, the tungsten lamp was limited to
application in 16 mm. educational and
business films or to home movie use.

High Intensity Xenon Lamp
for Large Screen Illumination
JOSEPH P. KEARNEY
NICHOLAS J. RAINONE
Westinghouse Electric Corporation, Lamp Division

The lamp industry did not cease its search
for a higher brightness source and for
many years has been developing a line of
enclosed arc lamps. The first of these suitable for projection usage was the mercuryargon short-arc lamp. A 10 minute warmup time and poor color rendition ruled it
out of the motion-picture projection field.
Next came the mercury-xenon lamp which
improved the warm-up time but once again
did not meet the color requirements of
motion-picture projection.

XENON SHORT-ARC
TENTIAL

~

RIMARY

ELLIPTICAL MIRROR

_-=-,'

SECONOARY SPHERICAL MIRROR

~ ~ECTION LENS

",_

\~

/~ /

--- ---==z-=--~

I
--------

FILM GATE

OFFERS BEST POLAMP

Out of the many sources explored, the
xenon short-arc lamp offered the most exciting potential. It has all the characteristics
needed, such as rapid warm-up, good color
and a continuous spectral response (Fig.
1). The development of xenon lamps was
begun for searchlight and instrument applications. While these lamps were lower in
wattage (up to 1000 watts) their development laid the foundation for things to
come. Use of xenon lamps for motionpicture projection had its beginning in Europe. The 1 KW and 2 KW lamps were
introduced for use in what we now consider
the small screen theatres.

Figure 2.
exciting era. The term "Wide Screen"
became a necessary label on the marquee
in order to attract customers. In the mad
rush to meet new demands, the industry
was forced to make many compromises. The
Iight sources in use in 1950 would not
properly illuminate the larger picture area so
the result was a bigger, but not better,
picture. In order to again meet acceptable
standards of good quality presentation it
was necessary for new technological improvements to be made in all phases of the
projection system. Included in these changes
were larger film formats, increased reel
size, and improved light sources.

Suddenly, during the early 1950's, the
motion-picture industry entered a new and

SPECTRAL DISTRIBUTION

I 0 ~-~------.------r---'------'---.-----.----r-------,

IMPROVEMENTS NEEDED IN THE
XENON SOU RCE
To provide the needed unit area of illumination the xenon lamp had to be made in
higher wattages. Furthermore, up to this
time it had only been possible to operate
the lamp in a vertical position. The diagram
in Figure 2 shows schematically the conventional vertical burning system which uses
an elliptical reflector to couple the light to
the optical system. The secondary mirror is
used to recapture some of the light to the
lIsed to recapture some of the Iight lost
from the front of the lamp. As can be seen,
the secondary mirror and the side arms of
the lamp create a large shadow area. In
addition, the pick-up angle of the elliptical
mirror is limited by the shape of the lamp
electrodes.
Figure 3 shows the schematic drawing of a
system with a lamp operating horizontally.
The need for a secondary mirror is eliminated and the lamp arms are placed so
that their cross-sectional area causes a
minimum of shadowing. By placing the lamp
anode away from the reflector, a much larger
pick-up angle is realized. Figure 4 shows
this comparison. An additional advantage
of horizontal operation is that the light
pick-up is symmetrical about the optical
system axis. Comparison tests show a 25
percent increase in screen illumination with
a horizontal operating system.

(f)

z
~ 8--u
2

-'
-'

2 6

o
I

5 41----1\'
I(f)

"-

(f)

II



Table of Contents for the Digital Edition of Theatre Design & Technology - May 1970

Contents
Theatre Design & Technology - May 1970 - 1
Theatre Design & Technology - May 1970 - 2
Theatre Design & Technology - May 1970 - 3
Theatre Design & Technology - May 1970 - Contents
Theatre Design & Technology - May 1970 - 5
Theatre Design & Technology - May 1970 - 6
Theatre Design & Technology - May 1970 - 7
Theatre Design & Technology - May 1970 - 8
Theatre Design & Technology - May 1970 - 9
Theatre Design & Technology - May 1970 - 10
Theatre Design & Technology - May 1970 - 11
Theatre Design & Technology - May 1970 - 12
Theatre Design & Technology - May 1970 - 13
Theatre Design & Technology - May 1970 - 14
Theatre Design & Technology - May 1970 - 15
Theatre Design & Technology - May 1970 - 16
Theatre Design & Technology - May 1970 - 17
Theatre Design & Technology - May 1970 - 18
Theatre Design & Technology - May 1970 - 19
Theatre Design & Technology - May 1970 - 20
Theatre Design & Technology - May 1970 - 21
Theatre Design & Technology - May 1970 - 22
Theatre Design & Technology - May 1970 - 23
Theatre Design & Technology - May 1970 - 24
Theatre Design & Technology - May 1970 - 25
Theatre Design & Technology - May 1970 - 26
Theatre Design & Technology - May 1970 - 27
Theatre Design & Technology - May 1970 - 28
Theatre Design & Technology - May 1970 - 29
Theatre Design & Technology - May 1970 - 30
Theatre Design & Technology - May 1970 - 31
Theatre Design & Technology - May 1970 - 32
Theatre Design & Technology - May 1970 - 33
Theatre Design & Technology - May 1970 - 34
Theatre Design & Technology - May 1970 - 35
Theatre Design & Technology - May 1970 - 36
Theatre Design & Technology - May 1970 - 37
Theatre Design & Technology - May 1970 - 38
Theatre Design & Technology - May 1970 - 39
Theatre Design & Technology - May 1970 - 40
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2021winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2021winter_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2020fall_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2020fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2020summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2020summer_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2020spring_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2020spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2020winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2020winter_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2019fall_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2019fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2019summer_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2019summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2019spring_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2019spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/usitt_techexpoguide_2019_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/usitt_techexpoguide_2019
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2019winter_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2019winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2018fall_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2018fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2018summer_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2018summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2018spring_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2018spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2018winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2017fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2017fall_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2017summer_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2017summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2017spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2017spring_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/usitt_techexpoguide_2017_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/usitt_techexpoguide_2017
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2017winter_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2017winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2016fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2016summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2016spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2016spring_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2016winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2015fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2015summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2015spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2015winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2014fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2014summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2013winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2013summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2013fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2013spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2012winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2012fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2012summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2012spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2011winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2011fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2011summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2011spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2010winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2010fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2010summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2010spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2009winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2009fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2009summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2009spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2008winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2008fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2008summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2008spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2007winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2007fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2007summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2007spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2006winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2006fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2006summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2006spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2005winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2005fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2005summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2005spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2004winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2004fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2004summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2004spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2003winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2003fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2003summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2003spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2002winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2002fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2002summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2002spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2001winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2001fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2001summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2001spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2000winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2000fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2000summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2000spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1999winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1999fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1999summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1999spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1998winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1998fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1998summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1998spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1997winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1997fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1997summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1997spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1996winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1996fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1996summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1996spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1995winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1995fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1995summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1995spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1994winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1994fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1994summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1994spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1993winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1993fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1993summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1993spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1992winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1992fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1992summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1992spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1991winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1991fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1991summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1991spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1990fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1990summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1990spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1989winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1989fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1989summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1989spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1988winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1988winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1988fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1988summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1988spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1987winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1987fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1987summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1987spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1986winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1986fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1986summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1986spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1985winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1985fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1985summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1985spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1984fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1984summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1984spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1983winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1983fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1983summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1983spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1982winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1982fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1982summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1982spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1981winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1981fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1981summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1981spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1980winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1980fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1980summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1980spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1979winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1979fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1979summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1979spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1978winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1978fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1978summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1978spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1977winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1977fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1977summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1977spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1976winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1976fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1976summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1976spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1975winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1975fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1975summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1975spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1974Dec
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1974Oct
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1974May
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1974Feb
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1973Dec
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1973Oct
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1973May
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1973Feb
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1972Dec
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1972Oct
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1972May
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1972Feb
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1971Dec
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1971Oct
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1971May
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1971Feb
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1970Dec
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1970Oct
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1970May
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1970Feb
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1969Dec
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1969Oct
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1969May
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1969Feb
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1968Dec
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1968Oct
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1968May
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1968Feb
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1967Dec
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1967Oct
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1967May
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1967Feb
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1966Dec
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1966Oct
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1966May
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1966Feb
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1965Dec
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1965Oct
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1965May
https://www.nxtbookmedia.com