TIMBER SLIDES AND CHUTES 
267 
Trailing; slides may be made from sawed timbers when the 
latter can be readily secured. A type of patent portable slide 
used in Pennsylvania and New York is shown in Fig. 90. The 
timbers are three in nimiber and are made 8 feet long for ease in 
handling. Maple and birch are preferred for timbers, which 
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Fig. 90. — The Sykes Trailing Log Slide. 
may be made from the lower grade material. They meet over 
the center of a plate, Fig. 90a, which may be placed flat on the 
ground, or supported on crib work when it is necessary to elevate 
the slide in order to prevent abrupt changes in grade. The main 
slide timbers A are made in the form of a trapezoid, two being 
sawed from one rectangular piece as shown in Fig. 906. 
A slide of this character is well adapted to conditions where 
a trailing chute can be used to advantage and is more economical 
than a pole slide because the various parts can be used repeatedly. 
When a slide is being built the materials are brought to the 
foot of it and then dragged by horses to the upper end where con- 
