s sulphate, is the green vitriol. The vitriol combines with
the potash of the soap, and the iron oxide is precipitated with
the fatty acid as insoluble iron soap. This precipitate is then
washed, dried and mixed with linseed oil.

** Building a House in a Tree Top [146]

The accompanying photograph shows a small house built in a tree
top 20 ft. from the ground. The house is

[Illustration: Lofty Sentry Box for Guarding Watermelon Patch]

5 ft. wide, 5 ft. 1 in. long, and 6 ft. 6 in. high. A small
platform, 2 ft. wide, is built on the front. Three windows are
provided, one for each side, and a door in front. The entrance is
made through a trap door in the floor of the house. This house was
constructed by a boy 14 years old and made for the purpose of
watching over a melon patch.
--Contributed by Mack Wilson, Columbus, O.

** How to Make a Lamp Stand and Shade [147]

A library light stand of pleasing design and easy construction is
made as follows: Square up a piece of white oak so that it shall
have a width and thickness of 1-3/4 in. with a length of 13 in.
Square up two pieces of the same kind of material to the same
width and thickness, but with a length of 12 in. each. Square up
two pieces to a width and length of 3 in. each with a thickness of
1-1/8 in.

If a planing mill is near, time and patience will be saved by
ordering one piece 1-3/4 in. square and 40 in. long, two pieces
1-1/8 in. thick and 3 in. square, all planed and sandpapered on
all surfaces. The long piece can then be cut at home to the
lengths specified above.

The 13-in. piece is for the upright and should have a 1/2-in. hole
bored the full length through the center. If the bit is not long
enough to reach entirely through, bore from each end, then use a
red-hot iron to finish. This hole is for the electric wire or gas
pipe if gas is used.

The two pieces for the base are alike except the groove of one is
cut from the top and of the other from the under side, as shown.
Shape the under sides first. This can best be done by placing the
two pieces in a vise, under sides together, and boring two holes
with a 1-in. bit. The center of each hole will be 2-1/2 in. from
either end and in the crack between the pieces. The pieces can
then be taken out, lines gauged on each side of each, and the wood
between the holes removed with turning saw and scraper steel.

The width of the grooves must be determined by laying one piece
upon the other; a