131 
PARK AND CEMETERY. 
them high enough. These species 
form large branches very low, the 
large limbs frequently obstructing 
traffic, and on this account when 
mature it is not desirable to prune 
them. 
The Ginkgo, a native of Japan, has 
been recommended very highly in re- 
cent years as a shade tree, and ex- 
cellent specimens of this tree may be 
found growing farther south. It does 
particularly well in Washington, 
where there is a fine avenue of them 
on the Agricultural grounds. It 
grows very slowly here, however, as 
we seem to be out of range for condi- 
tions that will promote its best develop- 
ment. 
Alost of our street trees have their 
enemies, both insect and fungous. 
The elm suffers chiefly from the bee- 
tle and the sugar maple from borers, 
which may usually be found on trees 
injured from some other cause, how- 
ever. The tulip tree is almost al- 
ways disfigured by some insect, and 
the horse-chestnut and sycamore are 
subject to a lea; fungus. The Italian 
poplar is often affected by ru;;t, the 
Carolina poplar is subject to borers 
and many other trees, especially the 
maples, suffer each year from sun- 
scorch to some extent. 
Most of the injury caused by fungi, 
however, is the result of poor prun- 
ing or mechanical Ui juries, particu- 
larly when antiseptic methods have 
not been employed in caring for the 
wounds. There are various wound 
fungi which testify to the results of 
poor pruning and lack of proper an- 
tiseptic treatment. Some fungi, for 
example, Nectria, are the result of 
winter killing, and occasional injury 
is caused by slight discharges of 
lightning and frost cracks which cause 
wounds favoring the development of 
fungi, which flourish more readily on 
wounded trees. 
Various root injuries occur ' from 
changing the grade of streets, putting 
in curbstones, digging man-holes, etc. 
and a too common source of injury 
may be traced directly to horses’ 
teeth, the Injudicious use of lawn- 
mowers, etc. To prevent injury from 
lawn-mowers the sod should be re- 
moved from around the tree for a 
distance of a foot or more, and with 
the large number of tree guards now 
on the market at reasonable prices 
much of the injury from horses’ 
teeth may be obviated. Of the vari- 
ous types of tree-guards in use, one 
of the most practical and cheapest 
is that made out of No. 15 Clinton 
wire, with a mesh, cut i.n strips 
about seven feet long and wound 
about the tree. 
The practice of placing signs on 
trees should be condemned since ugly 
scars are often caused by the tree’s 
over-growing the sign which is in it- 
self a defacement. 
One of the greatest difficulties with 
which trees have to contend is the 
wire problem. The rights of trees 
in the street are at least equal to 
those of wires, but it often becomes 
a difficult matter to string wires 
through a street without interfering 
with trees. Among the different ways 
of dealing with wires may be men- 
tioned burying them, which is too 
costly in some cases; using the ring 
or cable construction in the case of 
telephone wires, or placing the wires 
on private property in the rear of 
buildings. In the case of trolley and 
electric wires, the ring construction 
method is out of the question, and in 
some cases placing them on private 
property is not practicable. Many 
poles are attached to trees by means 
of guy wires, and in our estimation 
there is very little harm in this prac- 
tice providing it is properly done. We 
do not believe the lagbolt system is 
a good one, but passing a loop around, 
a tree and usin.g blocks to prevent 
contact of the wire with the tree is 
better than res.jrting fo the use of 
duplicate poles and props. In many 
cases it is unnecessary to attach gui' 
wires from poles to trees since the 
poles can be imbedded in Portland 
cement and held firmly in place, which 
would prevent much injury to trees. 
It should be pointed out, however, 
that there is always a risk in attach- 
ing wires in any way to trees, as 
lightning discharges are likely to pass 
from the guy wires to the trees and 
damage them, and a great deal of 
disfiguration is caused by live wires 
coming into contact with those that are 
dead. 
No authentic cases are known of an 
alternating current, of wdiatever po- 
tential, killing trees, and the injuries 
from this current are restricted to 
burning and disfiguration. High ten- 
sion currents are more dangerous 
than those of low tension, consequent- 
ly more attention must be given to 
the matter of insulation. There are 
authentic cases of a direct current, 
however, such as is employed by elec- 
tric railways, killing trees, and there 
is evidence to support the idea that 
trees may be injured or killed by be- 
ing connected by guywires with this 
system. 
Many more trees are injured by gas 
than formerly, which is due to the 
fact that gas is used much more ex- 
tensively, is conveyed in larger pipes 
and the system of calking the joints 
is quite different from that formerly 
employed. A very large percentage 
of gas escapes into the soil annually, 
and many shade trees are killed each 
year in this way. Gas poisoning is a 
distinct type of poisoning, and may 
be readily distinguished by one fa- 
miliar with the diagnosis of such 
trees. Trees poisoned by gas are 
subject to extremely rapid disinteg- 
ration; the bark falls off soon after 
they have been killed, the wood be- 
comes ver}" brittle and the tree is in 
a condition dangerous to its health and 
growth. 
Occasional injury is brought about 
by atmospheric gases, — the result of 
the combustion of coal. This is more 
likely to occur in places where large 
amounts of soft coal are burned. 
Evergreens are peculiarly susceptible 
to gas poisoning, and often die from 
its effects. 
Injury is sometimes caused by the 
use of crude petroleum or kerosene. 
These are frequently employed for 
spraying the trunks of trees for the 
Woolly Aphis and other insects, but 
it is never safe to apply thefn even 
when mixed with water, and ma..y of 
the banding substances which have 
been used in connection with the sup- 
pression of the Gypsy Moth are ex- 
tremely injurious to trees. 
Much attention has been given in 
recent years to filling trees, and by 
this practice the life of a tree is un- 
doubetdly prolonged. There are two 
methods of treatment: one consisting 
in cleansing the cavities thoroughly, 
removing all decayed tissue and treat- 
ing the interior with tar or paint. 
The orifice of the cavity is then cov- 
ered with tin and painted. In the 
other method the tree is filled with 
Portland cement after it has been 
thoroughly cleaned and disinfected, 
using the same proportions as are 
ordinarily employed in construction 
work. One of the difficulties in the 
use of Portland cement for this work 
is the cracking of the cement in large 
cavities when the tree sways, which 
allows fungi to enter and reinfect the 
tree. Much more attention is given 
to the care of trees than formerly, 
and there are several reliable firms 
which are doing excellent work at the 
present time. 
This process of tree filling has pre- 
viousI\- been described in Park and 
Cemetery and other troubles and prob- 
lems affecting trees will be d'seussed at 
a later date. 
