IMPROVEMENTS IN THE PREPARATION AND USE OF WOOD FOR THE CONSTRUCTION OF PAVEMENT
Year: 1873

page_text: PROVISIONAL SPECIFICATION left by William Alexander Lyttle at
the Office of the Commissioners of Patents, with his Petition, on
the 20th November 1873.
I, WILLIAM ALEXANDER LYTTLE, of the Grove, Hammersmith, in
the County of Middlesex, Engineer, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN THE PREPARATION AND USE OF WOOD FOR
THE CONSTRUCTION OF PAVEMENT," to be as follows:-
I cut the timber into boards, and then divide each board into short
pieces of a length exactly equal to the depth of the required pavement.
Other boards are also provided of any convenient length, the width of
which is equal or nearly equal to the depth of the pavement. The
latter I shall designate the "longitudinal boards," and the former short
vertical pieces the "vertical boards." All these pieces of wood are then
boiled in molten pitch, or in pitch diluted with any desired hydrocarbon
oil, as described in my Letters Patent Numbered 1434, of this year,
entitled "Improvements in the Preservation of Timber;" or they are

page_text: first boiled in creosote or otherwise treated with any desired pickling or
preservative process, and next boiled for a short time in pitch or other
bituminous matter of sufficient fusibility to enable it to stick tenaciously
to the surface of the wood.
In order to lay a pavement with these materials a foundation should
be prepared in the usual way, either by thoroughly ramming the levelled
bed of the roadway or other ground to be paved or by laying a founda-
tion of concrete, with or without a layer of pitch or asphalte, or by
providing a substratum or floor of horizontally laid wooden slabs. Upon
this foundation a longitudinal board, hot from the bath of boiling pitchy
solution, is set on edge and held firmly in a perpendicular or nearly
perpendicular plane by means of any convenient support on one side.
Against the other side of this board a row of vertical boards, also hot
from the pitchy bath, is quickly set, and the vertical pieces, standing
with the grain of the wood vertical, are soldered by the pitch to each
other, edge to edge, as well as to the longitudinal board. Another
hot longitudinal board is now quickly set on edge and pressed closely
against the exposed sides of the vertical boards in the row last laid so
as to be thoroughly soldered thereto by the hot pitch. Another row of
vertical boards is next laid in the same way, and followed by a row
of longitudinal boarding of the same length, and so on in alternate
rows of longitudinal and vertical boarding, soldered together into one
continuous unbroken mass for any required length or area of pavement.
In laying the boarding as described it is desirable to observe the same
principles in arranging the boards and courses of boards as are followed
in brick laying, by taking care that when two longitudinal boards are
joined end to end in a wide pavement the next adjacent junction of two
such pieces shall not be in the same line of traffic or roadway.
Slabs or board-like pieces of any asphalte may be alternated with the
boards in this arrangement, or may be substituted for either the vertical
or longitudinal pieces if desired. The best plan of laying such slabs is
to spread the asphalte on one side of the board, thus using it as a mortar
between two rows of boards.
The asphalte need not be carried down the full depth of this wooden
pavement, and in that case a narrow piece of board of the same thick-
ness may underlie and thus supplement fully the required depth of that
row or layer of which the asphalte forms the upper part.

page_text: The aforesaid boards may also be laid inclined from the perpendicular
at any desired angle, their upper edges being chamfered or bevelled off
so as to present a horizontal surface, and any pressure upon this pave-
ment will thus tend to force the boards further from the perpendicular,
and therefore into closer adhesion to each other.