Antique lloyd’s hygrodeik measures relative humidity. Dew points with wet and dry bulbs using charts measuring high and low electrical tension.

Brass, glass, cloth, and mercury (in thermometers), measures 11-1/4″ x 8-3/8″ x 1-1/2, from early 1900’s, needs cleaning, unusual that it retains glass vessel for wet bulb (cracked at back right but intact – looks like it has been this way for decades). Thermometers are intact and reading.
Text on plated brass plate with chart and pointer reads.
The item “Antique Lloyd’s Hygrodeik Relative Humidity Instrument, A. Boston” is in sale since Tuesday, April 22, 2014. This item is in the category “Antiques\Science & Medicine (Pre-1930)\Scientific Instruments\Barometers”. The seller is “77-74″ and is located in Putnam, Connecticut. This item can only be shipped to United States.

Lloyd & Co, Boston