The Magnifying Reflector
Let the rays of light that pass through the magnifying glass in the
shutter be thrown on a large concave mirror, properly fixed in a
frame. Then take a third strip of glass, and stick any small object on
it; hold it in the intervening rays at a little more than the focal
distance from the mirror, and you will see on the opposite wall,
amidst the reflected rays, the image of that object, very large, and
beautifully clear and bright.