the
line of the tunnel had a much greater effect than the concentration of
that power at any one spot. It soon appeared that the water had found
its master. Protected by the pumps, which cleared a space for the
engineering operations--carried on in the midst, as it were, of two
almost perpendicular walls of water and sand on either side--the workmen
proceeded with the building of the tunnel at numerous points. Every
exertion was used to wall in the dangerous parts as quickly as possible;
the excavators and bricklayers labouring night and day until the work was
finished. Even while under the protection of the immense pumping power
above described, it often happened that the bricks were scarcely covered
with cement ready for the setting, ere they were washed quite clean by
the streams of water which poured from overhead. The men were
accordingly under the necessity of holding over their work large whisks
of straw and other appliances to protect the bricks and cement at the
moment of setting.

The quantity of water pumped out of the sand bed during eight months of
incessant pumping, averaged 2,000 gallons per minute, raised from an
average depth of 120 feet. It is difficult to form an adequate idea of
the bulk of the water thus raised, but it may be stated that if allowed
to flow for three hours only, it would fill a lake one acre square to the
depth of one foot, and if allowed to flow for one entire day it would
fill the lake to over eight feet in depth, or sufficient to float vessels
of 100 tons burthen. The water pumped out of the tunnel while the work
was in progress would be nearly equivalent to the contents of the Thames
at high water, between London and Woolwich. It is a curious circumstance
that notwithstanding the quantity thus removed, the level of the surface
of the water in the tunnel was only lowered about 2.5 to 3 inches per
week, proving the vast area of the quicksand, which probably extended
along the entire ridge of land under which the railway passed.

The cost of the line was greatly increased by the difficulties
encountered at Kilsby. The original estimate for the tunnel was only
99,000 pounds; but before it was finished it had cost more than 100
pounds per lineal yard forward, or a total of nearly 300,000 pounds. The
expenditure on the other parts of the line also greatly exceeded the
amount first set down by the engineer; and before the works were finished
it was more than doubled. The lan