Graphoplex Hydraulic Comsip Revaco I slide rule full set 1950 France

This highly customized slide rule comes in the original leather sleeve and with the manual. It was made by Graphoplex from France in the French language for the Company “Comsip Automation”. The model is known as the Revaco I a.k.a. Regle a Calcule de vannes et de debitmetris (there is also a model Revaco II). It was specifically made for calculating gas flow and pressure according the Venturi effect and hydraulic laws in the 1950’s. It has scales on the front and back and short instructions in French on the back as well, the cursor is one of a kind. Everything including manual is in French. The curser and rule are complete and in very good condition. The leather sleeve and manual show some minimal signs of use and age. It measures 24 cm or 9 3/4 inches. Do check the attached video on how to work your vintage man tool : slide rule operation instructions!