ter-pipes, aqueducts, and
reservoirs. When masticated and prepared, it is a substitute for costly
gums as applied to numerous purposes. Combined with a small portion of
ligneous matter, it constitutes a fuel of greater evaporating power than
coal, and, when pulverized and scattered over growing potato-plants or
other vegetables, it prevents their destruction by insects or blight,
and acts also as a fertiliser of the soil. Essential and viscid oils are
obtained by various well-known processes from bituminous substances, but
from none in such abundance and possessing such valuable properties as
the oils extracted from the bitumen of the lake of Trinidad, as well as
from the petroleum of springs still in activity."[23]

[23] The following patents, for the use of the Trinidad bitumen, were
taken out by Lord Dundonald:--1851. "Improvements in the construction
and manufacture of sewers, drains, waterways, pipes, reservoirs, and
receptacles for liquids or solids, and for the making of columns,
pillars, capitals, pedestals, bases, and other useful and ornamental
objects, from a substance never heretofore employed for such
manufactures."--1852. "Improvements in coating and insulating
wire."--1852. "Improving bituminous substances, thereby rendering them
available for purposes to which they never heretofore have been
successfully applied."--1853. "Improvements in producing compositions or
combinations of bituminous, resinous, and gummy matters, and thereby
obtaining products useful in the arts and manufactures."--1853.
"Improvements in apparatus for laying pipes in the earth, and in the
juncture of such pipes."

The "Observations on the long-desired, yet still unaccomplished
proceeding, whereby to effect the embankment of the Thames and free the
river from pollution," by the Earl of Dundonald, are especially
interesting at the present time:--"It will probably be admitted that the
Thames above bridge is unnecessarily broad, unless considered as a
recipient for back-water; and that the long margin of shallow water
between London Bridge and that of Vauxhall is of little importance, even
for that purpose, as gravel, sand, and other substances, may
advantageously be removed from the central bed of the river, fully to
compensate for the water that would be excluded by an embankment of
one-sixth on both sides of the channel.

"An easy method of accomplishing this object would be to c