A patent application by the makers of the ovens, (both of which were made during the war) and two independent testimonies confirmed the capacity of the crematoria. Because the 4,756 figure is evidence of the Nazis equipping a camp of a maximum of 125,000 prisoners with the facility to cremate 140,000 of them per month. Critics of Leuchter explain that this reveals extermination was the true purpose of Auschwitz: a camp with the capacity to reduce its entire population to ash on a monthly basis was not merely a benign internment camp.