Penetrometer photographed on May 14th, 1946

Penetrometer photographed on May 14th, 1946. Built at the CNRS’s Cold Laboratory, this penetrometer was composed of a cylindrical penetration section a few millimeters long and a sliding scale indicating the weight of the load. Roger Ulrich was the author of summary works, including The Life of Fruit and Cold at the Service of Man, but his career began with his thesis on fruit’s reactions to experimental injury. This research led him to study the effects of low temperatures on fruit ripening. Starting in 1933, he served as assistant director and then director of the ONRSII’s experimental Cold Laboratory. He then occupied a similar post at the CNRS’s Laboratory of Plant Biology, which became the Laboratory of Physiology of Harvested Plant Organs in 1958. Extract from the book Inventions 1915-1939 by Luce Lebart.