cks.

The bottom is covered with matched boards not over 5 in. wide.
These pieces are placed together as closely as possible, using
white lead between the joints and nailing them to the edges of the
side boards and to a keel strip that runs the length of the punt,
as shown in Fig. 2. Before nailing the boards place lamp wicking
between them and the edges of the side boards. Only galvanized
nails should be used. In order to make the punt perfectly
watertight it is best to use the driest lumber obtainable. At one
end of the punt a skag and a rudder can be attached as shown in
Fig. 3.

[Illustration: Easy to Build and Safe to Use]

** Photographers' Printing Frame Stand [123]

When using developing papers it is always bothersome to build up
books or

[Illustration: Adjustable to Any Height]

small boxes to make a place to set the printing frame in front of
the light. Details for making a small stand that is adjustable to
any desired height are shown in the sketch. In Fig. 1 is shown the
construction of the sliding holder. A piece of 1/4-in. gas pipe,
A, is cut 1 in. long and fitted with a thumbscrew, B. The piece of
pipe is soldered to the middle on the back side of a piece of
metal that is about 4 by 4-1/2 in. with its lower edge turned up
to form a small shelf as shown at C. The main part of the stand is
made by inserting a 5/16-in. rod tightly into a block of hard
maple wood that is 1 in. thick and 3-1/2 in. square (Fig 2). The
pipe that is soldered to the metal support will slide up and down
the rod and the thumbscrew can be set to hold it at the desired
point.

** Heat and Expansion [124]

Take an electric light bulb from which the air has not been
exhausted and immerse it in water and then break off the point. As
there is a vacuum in the bulb it will quickly fill with water.
Shake the bulb gently until a part of the water is out and then
screw the bulb into a socket with the point always downward. Apply
the current and the heated air inside will soon expand and force
the water out with great rapidity. Sometimes this experiment can
be done several times by using the same bulb.
--Contributed by Curtiss Hill, Tacoma, Wash.

** Photographing a Streak of Lightning [124]

The accompanying illustration is a remarkable photograph of a
streak of lightning. Many interesting pictures of this kind can be
made during a storm at night. The camera is set in a place where
it will not get wet and left stan