Same Cavity Properly Filled.]

Trees that tend to split: Certain species of trees, like the linden and
elm, often tend to split, generally in the crotch of several limbs
and sometimes in a fissure along the trunk of the tree. Midwinter is
the period when this usually occurs and timely action will save the
tree. The remedy lies in fastening together the various parts of the
tree by means of bolts or chains.

A very injurious method of accomplishing this end is frequently
resorted to, where each of the branches is bound by an iron band and
the bands are then joined by a bar. The branches eventually outgrow
the diameter of the bands, causing the latter to cut through the
bark of the limbs and to destroy them.

Another method of bracing limbs together consists in running a
single bolt through them and fastening each end of the bolt with a
washer and nut. This method is preferable to the first because it
allows for the growth of the limbs in thickness.

[Illustration: FIG. 121.--Diagram Showing the Triple-bar Method of
Fastening Limbs.]

A still better method, however, consists in using a bar composed of
three parts as shown in Fig. 121. Each of the two branches has a
short bolt passed through it horizontally, and the two short bolts
are then connected by a third bar. This arrangement will shift all
the pressure caused by the swaying of the limbs to the middle
connecting-bar. In case of a windstorm, the middle bar will be the
one to bend, while the bolts which pass through the limbs will
remain intact. The outer ends of the short bolts should have their
washers and nuts slightly embedded in the wood of the tree, so that
the living tissue of the tree may eventually grow over them in such
a way as to hold the bars firmly in place and to exclude moisture
and disease. The washers and nuts on the inner side of the limbs
should also be embedded.

A chain is sometimes advantageously substituted for the middle
section of the bar and, in some cases, where more than two branches
have to be joined together, a ring might take the place of the
middle bar or chain.

Bolts on a tree detract considerably from its natural beauty and
should, therefore, be used only where they are absolutely necessary
for the safety of the tree. They should be placed as high up in the
tree as possible without weak