The text describes how to use a machine to represent objects naturally, involving a setup with paper, a frame, and mirrors. It details the adjustment of a convex lens and mirror angles to project an image of the object onto the paper. The process is explained for both perpendicular and inclined tables.
Method for Learning
Use of the machine to represent objects in their natural arrangement.
14. When you want to represent an object using this machine, you need to spread a piece of paper on the table, or even better, spread the paper over another board so that it overlaps, and then enclose this board covered in paper within a frame or border, securing it with two rules shaped like a dovetail.
15. Place the cylinder C (8), which operates with a screw, at the top of the machine, with a convex glass whose focus is about equal to the height of the machine above the table. Open the box behind the machine and tilt towards this opening the mirror L, so it forms a right angle with the horizon when you want to represent objects for the perpendicular table. If you then remove mirror H and board F, as well as the rules DE, DE, you will notice all objects being placed on the paper, sending rays to mirror L that can be reflected onto the convex glass, which you can raise or lower using the screw on the cylinder until the objects appear completely distinct.
When you wish to represent the same objects for the inclined table, you must give the mirror half the inclination you want to give to the table.