Alcoholometry @museum.de

F: Al-co-hol-o-me-try ...

M: ... is the science of determining the alcohol content of liquids.

F: Truly a science apart. Because determining alcohol content isn't straightforward. Three things need to be considered. Firstly:

M: Alcohol is lighter than water.

F: Secondly ...

M: Determining the alcohol level is temperature-dependent.

F: And thirdly ...

M: Water and alcohol have different rates of expansion depending on the temperature.

F: In the showcase we have various hydrometers on display. They were developed over the centuries to measure alcohol content. The first attempt was made in 1790 by a gentleman called Gilpin. At the behest of the British government, he investigated the relationship between the specific weight and the expansion of alcohol at different temperatures.

M: Gilpin was followed in 1799 by the German Jeremias Benjamin Richter. He introduced a specially calibrated hydrometer by weight. Cost: four thalers apiece. Richter's alcohol scale included some errors, but he deserves special credit: he was the first to introduce a special hydrometer in Germany.

F: Finally, in 1812, there was Professor Georg Tralles with his Investigations into the specific weights of alcohol and water mixtures. The combination of both resulted in hydrometers according to Richter and Tralles.