Author J. Th. Saconney, published 1913 (first printed in 1909)

 

This work is certainly much less known than Les Cerfs-Volants Militaires. The strange title is discouraging. Who knows what is the metrophotographie? In fact, it is just like photogrammetry. At that time, engineers and mathematicians had a large knowledge of descriptive geometry and they could do a lot of calculations on distances and angles.

A great part of the book is used to explain it. However, there are many things to discover, especially when it is so well explained, step by step.

Aerial photography is discussed twice. First in chapter III where it describes aerial photography from ballons, kites or airplanes. There is, as usual, many considerations on the interpretation of the image. I was so surprised to see all the informations that can be found just by measuring some points on the image. Now, I understand the meaning of "metrophotographie" which is given in the first paragraph of the book: " art of taking measures by the means of photography". In fact, it is much more than only calculating some distances and angles.

The second description on aerial photography is in annex 2: " Suspensions of cameras". There are some good ideas to take and to apply to modern cameras and actual kaping techniques. The pros and cons if different techniques are explained; one of them is the Saconney suspension (of course).

What surprised me more is the geometrical approach, even it is normal in this kind of book. It is my guess that Saconney is not known as he should be in the photogrammetry world.