rregular to show a continuous and closed circular path, but at
times the circular motion became very pronounced. It was observed
and the direction of rotation correctly stated by a man who was
unaware of the source of the motion. The production of the
circular motion can be explained in this way:

When the rubbing nail comes to a notch the release of pressure
sends the stick upward; this upward motion against the oblique
pressure upon the (say) right hand side gives also a lateral
component of motion towards the left. As the nail strikes the
opposite side of the notch the stick is knocked down again, this
motion relieves somewhat the oblique pressure from the right hand
side, and, the reaction from the holding (left) hand moves the
stick to the right slightly, so that it is back in the old
position for the next upward motion. Thus a circular or elliptic
motion is repeated for each notch, and the direction of this
motion is the same whether the nail be rubbed forward or back. For
oblique side pressure from the right (notches assumed upward), the
motion of the stick and hence of the revolving piece will be
counter-clockwise; if the pressure is from the left, it will be
clockwise.

That the motion of the revolving piece is due to a swinging
action, and not to friction of the pin in the hole, is proved by
experiments 3 and 4.
--Contributed by M. G. Lloyd, Ph.D., Washington, D. C.

** Home-Made Lantern [163]

[Illustration: Tin Can Lantern]

The accompanying picture shows a lantern which can be made almost
anywhere for immediate use. All that is needed is an empty tomato
or coffee can, a piece of wire and a candle. Make a hole a little
smaller than the diameter of a candle and about one-third of the
way from the closed end of the can, as shown. A wire is tied
around the can, forming a handle for carrying. This kind of
lantern can be carried against almost any wind and the light will
not be blown out.
--Contributed by G. A. Sloan, Duluth, Minn.

** A Study of Splashes [164]

When a rough, or greasy, or dusty sphere falls into a liquid, the
liquid is

[Illustration: Splashes from a Sphere In Milk and Water]

forced away from the sphere. If the sphere is quite smooth the
liquid rises up around and enclosing it in a sheath says Knowledge
and Scientific News.

Reproduced herewith are a series of photographs showing successive
stages in the entry of a rough sphere into milk and water, and the
resultant "ba