In 1909, M. Marconnet proposed patents on two jet engine ideas in which they both used compressors to propel propellants into the chambers.

“Valveless Marconnet”

-The basic idea of a valveless pulsejet is presented below.

-Now they needed forced air for their operation, so two new models with compressors appear.

"With Roots and Centrifugal compressors"