Opaque projector

They have been produced and marketed as artists' enlargement tools to allow images to be transferred to surfaces such as prepared canvas, or for lectures and discourses.

Swiss mathematician, physicist, astronomer, logician and engineer Leonhard Euler demonstrated an opaque projector around 1756.

[2] Around 1872 Henry Morton used an opaque projector in demonstrations for huge audiences, for example in the Philadelphia Opera House which could seat 3500 people.

His machine did not use a condenser or reflector, but used an oxyhydrogen lamp close to the object in order to project huge clear images.

A flat or solid original is projected on a larger sheet of paper onto a wall or easel, where the artist or craftsperson can trace the outline reliably.

An episcope which was used in a University of Cambridge lecture hall in the late 1800s
Small episcope for home use
Henry Morton's projection as illustrated in François Moigno's L'art des projections (1872)