The invention of the compass has an interesting backstory. In fact, compasses were meant as a tool for the military. Calculations using these instruments helped the army to use firearms with precision and accuracy. The brain behind the first geometric compass was the famous Italian astronomer Galileo Galilei. Later, other people figured out that this tool is extremely useful in other areas as well. Therefore, they became popular among mathematicians and math students. After some time, architects and designers also started using them.