was running out of money while working on his projects and asked Leibniz for help obtaining a paid post so he could continue his work.

In 1717 or 1718, Fahrenheit returned to Amsterdam and began selling barometers, areometers, and his mercury and alcohol-based thermometers commercially. By 1721, Fahrenheit had perfected the process of crafting and standardizing his thermometers. The superiority of his mercury thermometers over alcohol-based thermometers made them very popular, leading to the widespread