situation, and these rays
appear to proceed directly from that object.

The two moveable tubes H and I, at the extremity of which a glass is
placed, serve only to disguise the illusion, for they have no
communication with the interior of the machine. This instrument being
moveable on the stand E, may be directed to any object; and if
furnished with proper glasses, will answer the purpose of common
perspective.

The two moveable tubes, H and I, being brought together, the machine
is directed towards any object; and, desiring a person to look at the
end F, you ask him if he sees that object distinctly. You then
separate the two moveable tubes, and, leaving space between them
sufficiently wide to place your hand or any other solid body, you tell
him that the machine has the power of making objects visible through
the most opaque body; and as a proof, you desire him to look at the
same object, when to his great surprise he will see it as distinctly
as if no solid body interposed.

This experiment is the more extraordinary as it is very difficult
to conceive how the effect is produced; the two arms of the
case appearing to be made for the purpose of supporting the
perspective-glass; and to whatever object it be directed, the effect
is still the same.

_The Deforming Mirrors._

If a person look in a concave mirror placed perpendicularly to
another, (that is, supposing one mirror to be laid on the floor, and
the other attached to the ceiling,) his face will appear entirely
deformed. If the mirror be a little inclined, so as to make an angle
of 80 degrees, (that is, one-ninth part from the perpendicular,) he
will then see all the parts of his face, except the nose and forehead.
If it be inclined to 60 degrees; (that is, one-third part,) he will
appear with three noses and six eyes: in short, the apparent deformity
will vary at each degree of inclination, and when the glass comes to
45 degrees, (that is, half-way down,) the face will vanish. If,
instead of placing the two mirrors in this situation, they are so
disposed that their junction may be vertical, then different
inclinations will produce other effects, as the situation of the
object relative is quite different.

_The Magic Tube._

Procure a small tube of glass, whose canal is extremely narrow, and
open at both ends; let one end of it be plunged in water, and the
water within the tube will rise to a considerable height above the
external surface: or if two