against a city ordinance to build houses in shade-trees, and maybe it is;
but, fortunately for the boys, there are other trees which may be used for
this purpose. There is now, or was recently, an interesting tree-house on
Flatbush Avenue, Brooklyn; a house so commodious that it was capable of
accommodating as many as fifteen people; but it was not as pretty and
attractive a tree-house as the one located at the foot of Mount Tamalpais,
in Mill Valley, San Francisco, which is built after the plan shown by Fig.
95. This California house is attached to the trunk of a big redwood tree
and is reached by a picturesque bridge spanning a rocky canyon.

Tree-houses are also used as health resorts, and recently there was a
gentleman of Plainfield, Mass., living in a tree-house because he found
the pure air among the leaves beneficial; while down in Ecuador another
man, who feared malarial mosquitoes and objected to wild beasts and
snakes, built himself a house on top of an ibo-tree, seventy feet from the
ground. This is quite a pretentious structure and completely hides and
covers the top of the tree. It is located on the banks of the Escondido
River; and in this tropical country, while it may be a safe retreat from
the pests enumerated, it might not be so safe from lightning in one of
those violent tropical storms. But it is probably as safe as any house in
that country, for one must take chances no matter what kind of a house one
dwells in.

Primitive and savage men all over the world for thousands of years have
built dwellings in tree tops. In the Philippines many natives live in
tree-top houses. The Kinnikars, hill-tribesmen of Travancore, India, are
said to live in houses built in the trees, but in New Guinea it seems that
such houses are only provided for the girls, and every night the dusky
lassies are sent to bed in shacks perched in the tree tops; then, to make
safety doubly safe, the watchful parents take away the ladders and their
daughters cannot reach the ground until the ladders are replaced in the
morning.

The most important thing about all this is that a tree-house is always a
source of delight to the boys and young people, and, furthermore, the boys
have over and over again proved to the satisfaction of the author that
they themselves are perfectly competent to build these shacks, and not
only to build them but to avoid accidents and serious falls while engaged
in the work.

XVII

CACHES

THE dif