This is a Dr.Swett's thermometer sign that was purchased from the Grayson plantation( one of the first ever built in L.a). The thermometer still works. I stumbled upon this sign in a old shed behind a relatives house in Nederland, Tx. After researching what was wrote on the back, ii found that this plantation was used as a headquarters for the confederate army during the civil war. The Yankee invaders defeated the confederate army, burned all the cotton and freed the slaves. This sign was then purchased in 1930 and then resold in 1975. There are signatures on the back of people who have owned the sign and a claim that is was from the plantation.