We have been looking for a long time to create a device that would allow the projection of opaque bodies. A hospital extern, Mr. Thuillant, imagined a new device making it possible to project the view of long-term operations and to perceive, at the same time as movement, natural colors and relief.

Its device consists of a projector in which high intensity electric lamps burn. A water chamber, the upper and lower faces of which are transparent, is attached to the projector. This water is constantly and automatically renewed. An optical device, placed 70 centimeters above the operating table, allows the surgeon's movements to be projected. A microphone is installed at the same time. A loudspeaker transmits to the students the explanations that the teacher gives in a low voice while he operates.

Thanks to this system, student surgeons witness the most delicate operations and hear comments on the different phases.

P.: Prism M. Microphone; H. Speaker.