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et
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OUR ROADWAYS.
i
their bases, a groove is cut, which is filled with an
asphaltic mastic (pitch and tar), during the process of
laying. The blocks are laid on a concrete foundation,
the angle of each course being in an opposite direc-
tion to the previous one. The remainder of the
LIGNO-MINEItAL WOOD PAVEMENT.
joints to the surface are filled in with a grouting of
lime and gravel.
Carey's Wood Pavement is perhaps that which can
be most rapidly laid down and repaired, and is
formed as follows, viz.: the blocks are cut 4 in. wide
by 9 in. long and to the depth of 5 in. or 6 in. accord-
ing to traffic; these blocks are shaped with alternate
convex and concave ends, and are laid on a bed of
ballast or sand, averaging 2 in.; the joints which
have been left about J in. wide, are filled with a
grout of lime and sand. The advantages claimed
for this pavement are, that by the peculiar shaping