Rowbotham's Vaporiser Rowbotham’s vaporiser, consisting of a clear glass jar with a removable screw-in lid. The lid is attached to a metal filter, which is inserted into the jar and connected to a double tubing system: one tube leads to the patient-mask outlet, and the other allows air intake. A control valve is located at the top. Part of the Hadden Family collection. 1925-1975