be used.

It would be advisable, if possible, to have the part of the needle
that touches the contact points, as well as these points, of
platinum, as the arc that is likely to be formed will not destroy
the platinum as easily as it will the brass. A small wooden
containing case can now be made and the thermostat is complete.
There should be a large number of holes drilled in the sides, ends
and back of the case so that the air inside may be always of the
same temperature as the outside air.

In adjusting, testing, or calibrating your thermostat, make sure
that it is in the same position that it will be in when in use.

The connections of the thermostat for ringing one bell when the
temperature rises or falls to a certain value, are shown in Fig.
11. The connections of the thermostat for ringing one bell when
the temperature rises to a certain value and another bell when the
temperature falls to a certain value, are shown in Fig. 12. The
complete thermostat is shown in Fig. 13.

** A Tailless Kite [458]

The frame of a 3-ft. kite is made of two sticks, each 3 ft. long.
These are tied together so that the cross stick will be at a
distance of 15 per cent of the full length of the upright stick,
from its end, or in this case 5.4 in. The sticks may be made of
straight grained pine, 3/8 in. square, for small kites, and larger
hardwood sticks, for larger kites.

The cross stick is bent into a bow

[Illustration: Plan and Dimensions for Kite]

by tying a strong cord across from end to end. The center of the
bend should be 4-1/2 in. above the ends. The bend is shown in the
sketch. Connect all four ends or points with a cord, being careful
not to pull the bend of the cross stick down, but seeing that it
remains straight across the kite. When this is done the frame is
ready for the cover.

The cover will require 2-1/2 sheets of tissue paper, 20 by 30 in.,
which should be pasted together as the sketch indicates. Cut out
the paper, allowing 2 in. margin for lapping over the cord on the
frame. Place the frame on the cover with the convex side toward
the paper and paste the margin over the cord, allowing the paper
to bag a little to form pockets for the air to lift the kite. The
corners should be reinforced with circular pieces of paper pasted
over the ends of the sticks.

The flying cord is attached to the points A and B of the frame.
There is no cross cord. The kite will fly at right angles to the
flying cord. I