a large pool or tank where, by a system of planks fastened to a central
post, two bathers could go alternately up and down, one being in the
water while the other was in the air, an arrangement like the see-saw
which children are so fond of. It should have sufficient capacity to
accommodate a number of bathers at once, and should be as near as
possible to the sea, so as to be available by persons in bathing suits,
who have already had a salt bath.