ANTIQUE FRIEZ SLING PSYCHROMOTER HUMIDITY GAGE WAND BALTIMORE MARYLAND 1904

Description

Antique Sling Psychrometer made by Friez company in Baltimore Maryland. A device to measure humidity with two thermometers one with a sock that is wet and one without. The device is swung around and the difference between the two thermometers tells the level of humidity. Withnice leather case. Believed to be made prior to 1904 when the factory burned in the Baltimore Fire. Measures about 14 inches long. The Thermometers about 9 inches long.  It is Catalog number 552. Julian P. Friez established a factory on the corner of German and Grant Streets, Baltimore, Maryland, under the name of Julian P. Friez & Sons, Manufacturers of Weather Instruments. The Friez Co. was completely wiped out in the devastating fire of 1904, which cleared the whole section of Baltimore.