This heater, manufactured by James Allen of Marylebone Lane, London, is used for plain or medicated vapour  baths. It is, in fact, basically the same as the heater used to produce hot dry air when converting a bed into an invalid's Turkish bath, or to facilitate the treatment of a specific part of the body, such a single arm or leg.

It comprises the same cylindrical air compart-ment, with an opening at the front for the three-wick methylated spirits lamp. On top of the cylindrical air compartment is  a tightly fitting domed top, to which can be attached a right-angled tube and two tapered extensions to act as a heated air duct.

Here, however, the extensions have been removed, to be replaced with the flat clip-on top, shown front left of the photograph.  Behind this is a round container with cylindrical stem which is filled with water and then placed inside the heater, over the lamp and within the domed top.

In this way, with the top of the heater closed by the clip-on flat cap, the heater can be used directly in a cabinet, or beneath a chair.

But if the vapour is required elsewhere, the ducting attachments are connected instead.

Not shown in the photograph, is a perforated cylinder called a herb receiver  which can be fitted inside the neck of the water container. Herbs, or other curative agents, are then placed in the receiver so that the vapour passes through them before leaving the heater.

This photographed heater is in the collection of the Science Museum, London