2014 AD., Germany, 300th anniversary of the Fahrenheit temperature scale commemorative, Hamburg mint, 10 Euro, KM ?.

"Germany, Federal Republic, 300th anniversary of the Fahrenheit temperature scale commemorative, engraver: Victor Huster, Hamburg mint (""J""), 2014 AD., issue date: 06/11/2014,
10 Euro (32,5 mm / 14,04 g), copper-nickel (CuNi25), 14,00 g theor. mint weight, mintage 1.133.000 , medal alignment ↑↑, plain, incuse lettered edge,
Obv.: BUNDES / REPUBLIK / DEUTSCHLAND / 10 / EURO / J / 2014 , issuer, date and value in fields around German national emblem eagle, 12 stars of Europe in a small circle to r., mint mark "J" below circle.
Rev.: 300 / JAHRE / 1701 - °N / 1702 - °Rø / 0 - 32 - °F / 1730 - °Re / 1732 - °D / 1742 - °C / 1848 - K / 1859 - °Ra / FAHRENHEIT- / SKALA / VH , eight different temperature measuring scales in a timeline.
Edge: plain with incuse inscription ""EIN MEILENSTEIN DER MESSTECHNIK •• "" (""a milestone of measuring"").
KM ? .

Year / Mint Mark / Mintage
2014 / J / 1.133.000
(plus a similar proof issue made of 0.625 silver)

Fahrenheit (symbol °F) is a temperature scale based on one proposed in 1724 by the German physicist Daniel Gabriel Fahrenheit (1686–1736), after whom the scale is named. On Fahrenheit's original scale the lower defining point was the lowest temperature to which he could reproducibly cool brine (defining 0 degrees), while the highest was that of the average human core body temperature (defining 100 degrees). On the Fahrenheit scale, the freezing point of water is 32 degrees Fahrenheit (°F) and the boiling point is 212 °F (at standard atmospheric pressure). This puts the boiling and freezing points of water exactly 180 degrees apart.
more on http://en.wikipedia.org/wiki/Fahrenheit