174. TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 
was not completely stopped. The experiment extended over 
4 acres, and cost £9 (about 54 cwts. of bisulphide, costing 53s., 
being used, and £6, 7s. being spent on labour).” 
An apparatus in the form of a walking-stick is now being 
brought into use for the above purpose. It is pushed about 
2 inches into the ground, and then, on raising a lever, the point 
gets filled with } oz. of the bisulphide, which is squirted out side- 
wards on the lever being lowered again. 
To obviate danger of fires arising from sparks from railway 
engines, the Prussian Board of Public Works and Agriculture, 
etc., has issued new orders in 1905 for the preparation and treat- 
ment of protective strips along the sides of all new railway lines 
which may be constructed and pass through woodlands, while 
power is also given to compel proper measures to be taken on rail- 
ways already at work. It proceeds from the principle that the best 
protection consists in a belt of trees broad enough to catch the 
sparks, with the lower branches cut to a height of 5 feet (except 
along the edge close to the railway line), and inflammable matter 
cleared away, but not so as to lay the ground bare and induce 
deterioration of the soil. To prevent the spread of casual fires 
on the bank slope (which are often kindled by sparks), a 40-inch 
strip is to be thoroughly cleared down to the soil and hoed 
between it and the protective strip, and kept always free of 
inflammable matter. ‘The protective strip is to be from 40 to 50 
feet broad, and between it and the woods to be protected a 5 feet 
strip is also thoroughly cleared of inflammable matter, so as to lay 
bare the naked soil, and then hoed. ‘These two 4o- and 60-inch 
broad bare strips are to be united by similarly cleared cross- 
strips (like the rungs of a ladder) at distances of about 1 to 2 
chains (22-44 yards) apart, according to the extent of the danger 
run. On dry sandy soil, where danger is greatest, the protective 
belts are usually to be planted with Scots pine, as the thick bark 
it develops early offers good resistance to surface-fire, while its 
evergreen foliage catches the sparks at all seasons of the year; but 
for land of better quality, spruce is also recommended. Broad- 
leaved trees (birch, etc.) can also be planted on the latter, but on 
poor soil they do not thrive, and do not keep down grass, 
heather, and other inflammable weeds so well as Scots pine. The 
ministerial orders further include instructions for the formation of 
new protective strips and the treatment of those already formed, 
including the manner in which the growing-stock is to be cleared 
