The instruments of the commander educated in the mathematical sciences were often kept in cases and boxes. Magnetic compasses, quadrants, squares, rulers, drawing pens and, above all, compasses of various kinds formed the armamentarium of the military cartographer. The term "compasses" includes a broad array of instruments for drawing, measurement, and proportional calculation. In the late 16th century, the latter function was served to perfection by Galileo's geometric and military compasses.