rough sea will twist into most fantastic shapes steel joists 10
in by 8in, or even larger in size. Any extra cost incurred in
strengthening the gantries is well repaid if it avoids damage,
because otherwise there is not only the expense of rebuilding
the structure to be faced, but the construction of the work
will be delayed possibly into another season.

In order to ensure that the works below water are constructed
in a substantial manner, it is absolutely necessary that the
resident engineer, at least, should be able to don a diving
dress and inspect the work personally. The particular points to
which attention must be given include the proper laying of the
pipes, so that the spigot of one is forced home into the socket
of the other, the provision and tightening up of all the bolts
required to be fixed, the proper driving of the piles and
fixing the bracing, the dredging of a clear space in the bed of
the sea in front of the outlet pipe, and other matters
dependent upon the special form of construction adopted. If a
plug is inserted in the open end of the pipes as laid, the
rising of the tide will press on the plugged end and be of
considerable assistance in pushing the pipes home; it will
therefore be necessary to re-examine the joints to see if the
bolts can be tightened up any more.

Messrs. Siebe, Gorman, and Co., the well-known makers of
submarine appliances, have fitted up at their works at
Westminster Bridge-road, London, S.E., an experimental tank, in
which engineers may make a few preliminary descents and be
instructed in the art of diving; and it is distinctly more
advantageous to acquire the knowledge in this way from experts