Psychrometer, Humidity meter of the psychrometer type, with two thermometers in a standard, incomplete. The scale of both thermometers ranges from -12 ° to 44 ° Celsius. One thermometer has a sock around the mercury ball that is made moist. From the difference in temperature between the two thermometers, caused by the evaporation of the moisture, the humidity of the air can be read. The base of the standard is weighted with lead., H. Geissler (mentioned on object), 1846, wood (plant material), brass (alloy), glass, mercury, wax, textile materials, h 44 cm × w 13.1 cm × d 8.9 cm.
Psychrometer, Humidity meter of the psychrometer type, with two thermometers in a standard, incomplete. The scale of both thermometers ranges from -12 ° to 44 ° Celsius. One thermometer has a sock around the mercury ball that is made moist. From the difference in temperature between the two thermometers, caused by the evaporation of the moisture, the humidity of the air can be read. The base of the standard is weighted with lead., H. Geissler (mentioned on object), 1846, wood (plant material), brass (alloy), glass, mercury, wax, textile materials, h 44 cm × w 13.1 cm × d 8.9 cm