advantage of all changes of direction. The pump rod in the
windmill tower is provided with a swivel coupling, enabling the
mill head to turn completely round without altering the
position of the rod.




CHAPTER X.

THE DESIGN OF SEE OUTFALLS.


The detail design of a sea outfall will depend upon the level
of the conduit with reference to present surface of the shore,
whether the beach is being eroded or made up, and, if any part
of the structure is to be constructed above the level of the
shore, whether it is likely to be subject to serious attack by
waves in times of heavy gales. If there is probability of the
direction of currents being affected by the construction of a
solid structure or of any serious scour being caused, the
design must be prepared accordingly.

While there are examples of outfalls constructed of glazed
stoneware socketed pipes surrounded with concrete, as shown in
Fig. 21, cast iron pipes are used in the majority of cases.
There is considerable variation in the design of the joints for
the latter class of pipes, some of which are shown in Figs. 22,
23, and 24. Spigot and socket joints (Fig. 22), with lead run
in, or even with rod lead or any of the patent forms caulked in