Antique  cast iron and brass America Moistening Co. Boston Mass System of Hydrofication  Wet bulb /Dry Hydrometer. Overall height is almost 14 inches. Width is almost 6 inches and depth at its thickest is 2 1/4 inches. Weight is almost 5 pounds. It is made to be wall mounted. 

The small door to access the wet bulb water bottle opens/closes easily.  The info plate is brass etched with indicator numbers and at top the company's info. I don't have a firm date as to when this was manufactured but I would guess late 1800's or early 1900's. They were primarily used in the textile industry where the level of humidity control was very important in the weaving process to minimize thread breakage.

Info from their website: The original AMCO was founded in Providence, RI in 1888 manufacturing conventional air washers utilizing compressed air atomization for the air handling and humidifying needs of the textile industry. The present corporation was formed in 1983. In 1929, the company relocated to North Carolina to follow the movement of the textile industry to the Southeast. In the early years, AMCO served the textile industry with compressed air atomization of water and conventional air washers.

Please email me if you have any questions or if you would like to see any additional photos of particular area.  I welcome all questions and would much prefer to address any issues before you bid.

NOTE: I ESTIMATE ALL SHIPPING COST BASED ON EAST COAST TO WEST COAST RATES AS I HAVE NO WAY OF KNOWING WHERE IT WILL EVENTUALLY GO--SHOULD THE ACTUAL SHIPPING COST BE LESS, I PROVIDE A REFUND