26
HISTORICAL EXHIBITION
Opened by Professor M. Poivilliers on Tuesday, 6th September, 1960
Description
The historical Exhibition staged in the gymnasium of University College London
comprised a total of 225 separate displays ranging from very early times to the 1930’s
or a little later.
Of these, 50 were original pieces of apparatus collected together for the first
time from various sources all over the world. The remainder consisted of drawings,
plans or photographs of pieces of which the originals had been destroyed or lost, or
which for one reason or another could not be displayed. The whole exhibition thus
gave a very comprehensive view into the beginnings and history of photogrammetry.
In addition to apparatus, the exhibition was fortunate to be able to show some
extremely valuable originals of early work. Perhaps the most interesting of these were
some maps executed by Laussedat with his planchette in 1 850.
The display of early perspectographs and sketching devices contained an in
teresting picture by Dürer showing one of these instruments in use in the 16th century,
and it was instructive to see later in the exhibition how soon after the invention of
photography the idea of adapting it to devices of this kind appears to have occurred
simultaneously to several inventors. Furthermore, the number of topographical cameras
and photo-theodolites already produced before the end of the 19th century was indeed
very large. These were well represented in the exhibition. The padded saddle boxes in
which much of this equipment was carried takes one back to the days of horse trans
port, and the use of wet plate photography in the field and of tents for dark rooms,
shows our predecessors to have been very determined and persevering with their
inventions.
Long before the end of the century ground photogrammetry had established itself
as an accepted production technique for the preparation of maps in hilly country, and
large numbers of different ancilliary and plotting devices had begun to make their ap
pearance. In France, Germany and Canada, the method was in general use. In flatter
countries the ground view was not so well adapted to map making, and so as to over
come this disadvantage, many attempts were made to get the camera into the air. These
included the use of balloons, kites, parachutes and even pigeons, all of which were
portrayed in the exhibition. Some of the photographs taken from balloons are quite
remarkable for their clarity and definition, and all the more so when one considers
the difficulties of wet plate photography. It was in the 20th century that the aeroplane,
spurred on no doubt by the demands of the war in 1914, suddenly became a practical
proposition, and the earliest practical air survey cameras date from about that time.
The exhibition was fortunate to be able to show Messter’s Reihenbildner of 1915 and
various British air cameras by Williamson of about that date.
Elaborate Photogrammetric measuring tools and plotting machines emerged
gradually, by fresh invention and development, from devices that might well be de
scribed as little more than sketching aids and long before the aeroplane they had already
reached an advanced stage. The exhibition showed a number of most interesting
developments, including an early Pulfrich Stereocomparator and the original South
African Stereocomparator by Fourcade of 1904. Both these instruments incorporated
stereoscopic vision. Pictures were also shown of goniometers by Porro and Koppe who
established the principal of observing the photograph through the camera lens in order
to cancel out the lens distortions. This latter idea was adopted in many plotting
machines. Vivian Thompson’s semi-automatic plotting machine of 1909 was however
