Prick a hole in a card with a needle; place the same needle near the
eye, in a line with the card-hole, look by daylight at the end of the
needle, and it will appear to be behind the card, and reversed.
Prick a hole with a pin in a black card, place it very near the eye,
look through it at any small object, and it will appear larger as it
is nearer the eye; while, if we observe it without the card, it will
appear sensibly of the same magnitude at all parts of the room.