118 General Care of Trees 
from a thorn bush arranged somewhat loosely about the 
tree trunk ... as on the streets of Fontainebleau. The 
next in order of simplicity, perhaps, is the jacket of pine 
poles seen often in Berlin. These poles are fastened to- 
gether by means of wire and may be easily removed when 
desired. They are cheap and efficient, and not so conspicuous 
as the wooden boa so well known in America. In Frank- 
furt, jacket guards for young trees on retired streets are made 
of willow branches woven into tall tapering basket-like forms, 
quite unique in appearance. In Bonn, the fine old Horse- 
chestnut trees of Poppelsdorf Allee are protected in situ- 
ations exposed to passing vehicles with shafts of stone 
planted about the tree at a little distance from its base. 
These shafts are columns of basalt, brought from the north 
bank of the Rhine. 
‘In Washington and many other cities, the most common 
tree guard is an elongated box made of narrow boards, 
which encloses the stem of the tree up to a distance of five 
feet or more from the ground. ‘The box guard is easily 
made and very efficient. In London, the young trees are 
protected with wire netting, which is removed as the trees 
grow older, except in the case of those having tender bark, 
and on London streets, where iron guards are used, the 
trunk often had the additional protection of a wire covering. 
“The best guards are made of iron, and, although some- 
what expensive, are widely used, especially in Europe. In 
Paris and London, they are generally employed; in Frank- 
furt and Berlin, they are used on the busier streets; while 
in Antwerp, Bonn, and Cologne, they are being introduced 
with the trees recently planted. Unless city trees are under 
municipal control, the styles of iron guards are likely to be 
very varied and often cheap and inefficient. In Paris, they 
are contracted for by weight as well as measurement and 
