The Collaborative International Dictionary of English v.0.48:

Bathing \Bath"ing\, n.
   Act of taking a bath or baths.
   [1913 Webster]

   Bathing machine, a small room on wheels, to be driven into
      the water, for the convenience of bathers, who undress and
      dress therein.
      [1913 Webster]

WordNet (r) 3.0 (2006):

bathing machine
    n 1: a building containing dressing rooms for bathers [syn:
         bathhouse, bathing machine]