ottom to the top. The bottom of the gore is
one-third the width of the widest point. The dimensions and shape
of each gore are shown in Fig. 2.

The balloon is made up of 13 gores pasted together, using about
1/2-in. lap on the edges. Any good paste will do--one that is made
up of flour and water well cooked will serve the purpose. If the
gores have been put together right, the pointed ends will close up
the top entirely and the wider bottom ends will leave an opening
about 20 in. in diameter. A light wood hoop having the same
diameter as the opening is pasted to the bottom end of the gores.
Two cross wires are fastened to the hoop, as shown in Fig. 3.
These are to hold the wick ball, Fig. 4, so it will hang as shown
in Fig. 5. The wick ball is made by winding wicking around a wire,
having the ends bent into hooks as shown.

The balloon is filled with hot air in a manner similar to that
used with the ordinary cloth balloon. A small trench or fireplace
is made of brick having a chimney over which the mouth of the
paper balloon is placed. Use fuel that will make heat with very
little smoke. Hold the balloon so it will not catch fire from the
flames coming out of the chimney. Have some alcohol ready to pour
on the wick ball, saturating it thoroughly. When the balloon is
well filled carry it away from the fireplace, attach the wick ball
to the cross wires and light it.

In starting the balloon on its flight, take care that it leaves
the ground as nearly upright as possible.
--Contributed by R. E. Staunton.

** A Simple Steamboat Model [216]

The small boat shown in the accompanying sketch may have a length
of 12 to 18 in. and is constructed in the

[Illustration: Sectional View and Completed Boat]

following manner: A small steam boiler, A, is supported by two
braces over an alcohol lamp in the middle of the boat. A small
pipe is fastened to the top of the boiler in such a way that the
open end will be opposite the open end of another pipe, B,
somewhat larger in size. The pipe B opens into the stern of the
boat at C, as shown in Fig. 1. The steam, coming through the small
pipe A, is driven forcibly through the larger pipe B, and carries
with it a certain amount of air out through the opening C into the
water. As the boat is driven forward by this force, the steam
arises to the surface in the form of bubbles. The boat soon
attains considerable speed, leaving a long wake behind.

** To Remove Grease from M