The bathing machine was a device, popular in the 18th and 19th centuries, to allow people to change out of their usual clothes, change into swimwear, and wade in the ocean at beaches. Bathing machines were roofed and walled wooden carts rolled into the sea. Some had solid wooden walls while others had canvas walls over a wooden frame.
The bathing machine was part of etiquette for sea-bathing more rigorously enforced upon women than men but to be observed by both sexes among those who wished to be proper.
Especially in Britain, men and women were usually segregated, so nobody of the opposite sex might catch sight of them in their bathing suits, which (although extremely modest by modern standards) were not considered proper clothing in which to be seen.
The bathing machines in use in Margate, Kent, were described in 1805 as
four-wheeled carriages, covered with canvas, and having at one end of them an umbrella of the same materials which is let down to the surface of the water, so that the bather descending from the machine by a few steps is concealed from the public view, whereby the most refined female is enabled to enjoy the advantages of the sea with the strictest delicacy.
People entered the small room of the machine while it was on the beach, wearing their street clothing. In the machine they changed into their bathing suit, although men were allowed to bathe nude until the 1860s, placing their street clothes into a raised compartment where they would remain dry.
Probably all bathing machines had small windows, but one writer in the Manchester Guardian of May 26, 1906 considered them "ill-lighted" and wondered why bathing machines were not improved with a skylight. The machine would then be wheeled or slid into the water. The most common machines had large wide wheels and were propelled in and out of the surf by a horse or a pair of horses with a driver. Less common were machines pushed in and out of the water by human power. Some resorts had wooden rails into the water for the wheels to roll on; a few had bathing machines pulled in and out by cables propelled by a steam engine.
Once in the water, the occupants disembarked from the sea side down steps into the water. Many machines had doors front and back; those with only one door would be backed into the sea or need to be turned around. It was considered essential that the machine blocked any view of the bather from the shore. Some machines were equipped with a canvas tent lowered from the seaside door, sometimes capable of being lowered to the water, giving the bather greater privacy. Some resorts employed a dipper, a strong person of the same sex who would assist the bather in and out of the sea. Some dippers were said to push bathers into the water, then yank them out, considered part of the experience.