| | Manufactured to a British Meteorological Office design, this Hygrometer is normally located within a thermometer screen, but is easily accommodated elsewhere, since it is provided with a substantial mounting board.
Water drawn up from a glass reservoir by a cotton wick, provides moisture to a circle of muslin surrounding one thermometer bulb to produce a wet-bulb reading. The second thermometer will indicate air temperature. Supported by a metal strap attached to the back board, the water reservoir has a cover to prevent the ingress of particles. | | 
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