At that time, wood was expensive and they wanted to find a way to reduce fuel consumption without reducing the production of the liquid element. So they decided to make things right and went to find a chemist from the University of Glasgow named Joseph Black . He realized that to improve the distillation process, he had to understand why ice, or ice cream, takes time to melt.
The next time you go for an ice cream -or you go to have a gin and tonic with lots of ice-, put a thermometer on it. Your friends will laugh, but you will see something that also surprised Black: as long as it melts – or there is ice in the glass – the temperature will not rise. This is so because all the heat is used to change the shape of the water from a solid to a liquid . Only when all the ice cream has melted does the temperature begin to rise. In this way Black was able to tell distilleries the minimum amount of wood needed to evaporate a given volume of whiskey and how much cold water to use to condense it. What's more, these ideas inspired Watt to design his steam engine .
