Can Francesco De Marchi’s Treatise Be Used as Evidence of a Revolutionary Application of a Diving Bell Ventilation System as Early As 1535?

The material presents an analysis of the treatise by Francesco de Marchi with regard to the use of a diving bell described therein, developed by Guglielmo da Lorena in 1535. The analysis was conducted on the basis of the original 1599 text Della Architettvra Militare, incorporating contemporary knowledge in the fields of underwater work technology, diving physiology and medicine, and the history of technology.

Based on an estimation of the bell’s volume, pressure conditions, and the application of a validated ventilation model for hyperbaric facilities, the theoretical duration of the device’s protective function and the time required to reach the critical partial pressure of CO₂ were determined. The results indicate that, without active air exchange, prolonged underwater stay would have been physiologically unlikely.

In light of the conducted analysis, de Marchi’s treatise does not provide sufficient grounds to formulate a hypothesis about the existence in 1535 of an advanced ventilation system analogous to solutions known from later constructions.