here
is a yard with trees. Boxes for the martins should be large,
containing fifteen or more compartments, each ten inches high by eight
wide and eight deep, and each having a separate entrance. The martin
box or house should be placed twenty feet from the ground, upon the
top of a strong post or platform sustained by four smaller posts. If
vines are planted at the foot of the supports, they will be ornamental
and will make the houses more attractive to the birds. The English
sparrows will occupy these compartments; but if the martins conclude
to take possession they will push out the sparrows and their
belongings without assistance. Every spring I am amused in watching
the summary process of ejectment which the martins serve upon the
sparrows that have taken possession of their houses. In the morning
the sparrows may be in undisturbed possession, but by afternoon the
martins occupy their old quarters, having pushed out the nests of the
sparrows with their eggs or young.

The boxes for bluebirds and wrens should be smaller and have only one
compartment. They should be nailed in the tops of trees. If the
English sparrows build in them their nests should be broken up; and
this repeatedly, so long as they persist in building. If this is not
done the wrens and bluebirds will not come. They are incapable of
coping with the sparrows.

Note when the different birds arrive in the spring, making in this way
a bird calendar.

Notice also when the birds gather together into flocks in the late
summer or autumn, preparatory to taking their leave. The last bird of
his kind to leave should be as carefully noted as the first to arrive
in your calendar. Distinguish carefully the birds of passage that stop
only a short time to rest on their journeys north and south, and those
that stay and help to make the summer.

You will need to make frequent excursions afield, always taking your
notebook. Take first a small area and master the birds in that; then
gradually extend your territory. You can take no more healthful or
happy exercise. It will greatly increase the interest of children in
all their school duties if their teachers make occasional bird
journeys with them. Limit the size of the party to that number which
will keep still as a mouse while in bird-land. Encourage the children
also to make frequent excursions by themselves, in parties of three or
four. Instruct them to have the sun at their backs and to carry if
possible one g