than to depend solely upon the guidance of the divers engaged
upon the work which the engineer desires to inspect. Only a
nominal charge of one guinea for two descents is made, which
sum, less out-of-pocket expenses, is remitted to the Benevolent
Fund of the Institution of Civil Engineers. It is generally
desirable that a complete outfit, including the air pump,
should be provided for the sole use of the resident engineer,
and special men should be told off to assist him in dressing
and to attend to his wants while he is below water. He is then
able to inspect the work while it is actually in progress, and
he will not hinder or delay the divers.

It is a wise precaution to be medically examined before
undertaking diving work, although, with the short time which
will generally be spent below water, and the shallow depths
usual in this class of work, there is practically no danger;
but, generally speaking, a diver should be of good physique,
not unduly stout, free from heart or lung trouble and varicose
veins, and should not drink or smoke to excess. It is
necessary, however, to have acquaintance with the physical
principles involved, and to know what to do in emergencies. A
considerable amount of useful information is given by Mr. R. H.
Davis in his "Diving Manual" (Siebe, Gorman, and Co., 5s.),
from which many of the following notes are taken.

A diving dress and equipment weighs about l75 lb, including a
40 lb lead weight carried by the diver on his chest, a similar
weight on his back, and l6lb of lead on each boot. Upon
entering the water the superfluous air in the dress is driven
out through the outlet valve in the helmet by the pressure of