Looking to own a piece of scientific history and have a home you can take out a second mortgage on? We may have exactly the thing: a 300-year-old thermometer made by Daniel Gabriel Fahrenheit himself has recently appeared in a private collection, and will be auctioned off at Christie's on October 8.

Fahrenheit, a physicist and glassblower, is credited with inventing the mercury thermometer in 1714. This piece of science history is considered to be one of the first — if not the first — mercury thermometers ever made, dated somewhere between 1715 and 1730. Only two other mercury thermometers made by Fahrenheit exist, both of which are in a Netherlands museum.

This particular item measures just 4.5 inches, and is made of brass. It carries Fahrenheit's signature on it, and, of course, is numbered using the Fahrenheit temperature scale. The glass and mercury have been replaced since, but that's the way the thermometer was designed. It's expected that this precision piece of scientific instrumentation — seriously, this was a sought-after, research-grade, professional tool in its day — will fetch £100,000 at auction, or about $150,000.
Read more at http://www.tecca.com/news/2012/08/31/daniel-fahrenheit-thermometer/#UXetSfcFA4xohBhZ.99