On navigable waterways, a lock is
a particular type of device for raising
or lowering boats between stretches
of water at different levels. The
distinguishing feature of a lock is
a fixed chamber whose water level
can be varied; whereas in a boat lift
or inclined plane, it is the chamber
itself which moves. Locks are used
to make a river more easily navigable,
or to allow a canal to cross country
that is not level. The term airlock
was coined for a similar device used
to allow persons to pass to and from
a location in which a particular atmosphere
is maintained, such as underwater,
in space, or in a clean room.
|
|
