John Logie Baird (1888-1946)

MARCH, 1938

     TELEVISION
             AND
SHORT-WAVE WORLD

BAIRD
COLOUR
TELEVISION

    Here is an account of the Baird
    colour television which was demon-
    strated at the Dominion Theatre,
    Tottenham Court Road, last month.
    We understand that the system has
    been personally developed by Mr.
                     John L. Baird.

[NLS note: a graphic appears here – see image of page]
An exterior view of the projector room at the
Dominion Theatre. The large screen can be
      seen at the extreme left of the picture.

[NLS note: a graphic appears here – see image of page]
The transmitter at the Crystal Falace. This is mobile and can
                    be used for close-up or distant shots.

REMARKABLE results in colour
television were demonstrated by
the Baird Company at the
Dominion Theatre, Tottenham Court
Road, last month. The demonstra-
tion was remarkable in several ways
and it was the first of its kind ever
given, though in 1928 Mr. Baird
showed a picture a few inches square
in colour at the British Association
meeting in Glasgow. This, however,
was transmitted by wire.

In this latest development the size
of the picture is 12 ft. by 9 ft.
and the transmission by radio from the
South Tower of the Crystal Palace, a
wavelength of 8.3 metres being used.
Another special feature of the demon-
stration was that the colour is exceed-
ingly good and on the whole more
pleasing to the eye than are the latest
colour films. No claim was made
that the definition came up to the
standard of the ordinary transmis-
sions and Mr. Baird clearly stated
that this was regarded as a prelimin-
ary experiment. Even so, the demon-
stration was most impressive and
the results came as a surprise to
those who witnessed it.

The present apparatus is shown by
the photographs and drawings. It
transmits a 120-line picture, the scan-
ning at both transmitter and receiver
being by mechanical means. The
transmitter consists of a mirror drum
with twenty mirrors inclined at dif-
fering angles revolving at 6,000
r.p.m. These mirrors reflect the
scene to be transmitted through a
lens, causing an image to be formed
on a rotating disc with 12 concentric
slots at different distances from its
periphery. By this means the field
given by the 20-line drum is inter-
laced six times to give a 120-line pic-
ture repeated twice for each revolu-
tion of the disc. Each of the slots is
covered with a light filter, blue, green
and red being used alternately, the
effect of this being to transmit alter-
nate lines of the picture corresponding
to a blue-green image and a red
image.

At the receiving station a similar
device is employed, the rotating drum
in this case being much larger (12 in.
in diameter in place of the 8 in. drum
at the transmitter).

Light from a high-intensity arc
lamp is concentrated on the moving
aperture in the disc and yields suffi-
cient light to fill a screen 12 ft. by
9 ft. The projected picture could be
seen from all parts of the Dominion
Theatre, which has a seating accom-
modation of 3,000.

The programme included imper-
sonations of a military officer, a shiek
and a Turk. Two ladies exhibited
various coloured hats, and the pro-
gramme concluded with the White
Ensign and a coloured photograph of
the King. The actual objects tele-
vised were afterwards inspected at

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