n suggested by Lebon towards the end of the last
century, and a patent had been granted in this country in 1836 to Franz
Moll for this use of tar-products. But Bethell's process was put into a
working form by the great improvements in the apparatus introduced by
Breant and Burt, and to the latter is due the credit of having founded an
industry which is still carried on by Messrs. Burt, Bolton and Haywood on
a colossal scale. The "pickling" or "creosoting" of timber is effected in
an iron cylindrical boiler, into which the timber is run; the cylinder
being then closed the air is pumped out, and the air contained in the
pores of the wood thus escapes. The creosoting oil, slightly warmed, is
then allowed to flow into the boiler, and thus penetrates into the pores
of the wood, the complete saturation of which is insured by afterwards
pumping air into the cylinder and leaving the timber in the oil for some
hours under a pressure of 8 to 10 atmospheres.

All timber which is buried underground, or submerged in water, is
impregnated with this antiseptic creosote in order to prevent decay. It
will be evident that this application of tar-products must from the very
commencement have had an enormous influence upon the distillation of tar
as a branch of industry. Consider the miles of wooden sleepers over which
our railways are laid, and the network of telegraph wires carried all over
the country by wooden poles, of which the ends are buried in the earth.
Consider also the many subaqueous works which necessitate the use of
timber, and we shall gain an idea of the demand for heavy coal-tar oil
created by the introduction of Breant's process. Under the treatment
described a cubic foot of wood absorbs about a gallon of oil, and by far
the largest quantity of the tar oils is consumed in this way at the
present time. Now in the early days of timber-pickling the lighter oils of
the tar, which first come over on distillation, and which are too volatile
for the purpose of creosoting, were in much about the same industrial
position as the tar itself before its application as a timber
preservative. The light oil had a limited use as a solvent for
waterproofing and varnish making, and a certain quantity was burnt as
coal-tar naphtha in specially constructed lamps, the invention of the late
Read Holliday of Huddersfield, whose first patent was taken out in 1848
(see Fig. 4). Up to this time, be it remembered, that chemists had not
found out wha