A well-constructed work:
I Kite Theory
II Kites and their handling
III Military applications

The presentation on kite theory is all the more complete as it describes the different historical approaches until E. Bertinet. It indicates the differences drawn from experience.
It could not have been better.

The second part is just as fertile on flat and cellular kites. He is the first author to develop as much all types of kites, all aspects of their handling and to make a synthesis. Of course, the airfoil kites and the stunt kites, unknown at his time, are missing.

The last part is not very military. It presents the civilian applications of the time with military interest, including kite aerial photography.

 

author: Théophile BOIS,
published in 1905 (magazine) and 1906 (book).

 

  Biography

When he wrote this book, Théophile Bois was a lieutenant in engineering. Born in Paris on February 10, 1880, he was at the Chaptal High School in Paris a brilliant student, in mathematics, physics-chemistry and philosophy. He entered the Ecole Polytechnique at the age of 18 and then the school of artillery and engineering applications in Fontainebleau. Promoted lieutenant in 1902, he joined the central establishment of the military aerostation. Captain in 1907, he passed the airship pilot's licence in 1908. CMarried in 1910, two daughters complete the family.
In 1915 and 1916 he fought in Champagne in the 1st RG. Commander of a unit, aboard his balloon he will wipe out the enemy's fire. Then, he will be battalion commander in charge of the inspection of the aerostation equipment. From 1919 to 1942, he remained in the control corps where he finished first class general controller.
Commander of the Legion of Honour, he had a citation to the Aeronautic Order, several testimonials of satisfaction, the War Cross. One of the testimonials of satisfaction is that of the Minister of War for kites and aerial photography. He died in 1971 at 91 years old, one year after his wife.
[Source Dominique Blondel on geneanet.org ]

 

  Commentary

The organization and writing are clear. T. Bois poses the hypotheses, gives the state of knowledge, contributes his understanding, develops the subjects and explains them. He formed teams of aeronauts, no doubt he was an excellent teacher.
Only a few units of measurement and terms have evolved over the last century. For a force, kgf has replaced kg; pressure, carcass, density, cable, are what today we call thrust, frame, wing loading, line.

His design on the theory part is:
 - to present the results of the aerodynamic experiments that form the basis of the theory.
 - study the functioning (conditions of equilibrium, stability) and the devices that ensure it.
 - study the lifting force, the influence of the cable, and overloads.

It is very much based on the kite theory of Emile Bertinet, which he complements by drawing on the experiments and work of C.F. Marvin of the American Weather Bureau and on the know-how of W.P. Köppen, a German meteorologist and climatologist of Russian origin.

This book is the world reference of the theory of the kite, unfortunately too ignored.