The Fairchild-Maxson line-of-position computer was an amazingly engineered mechanical computer in which the data sets of different celestial tables were coded onto gears and cams in cassettes that plugged into the main unit. By inputting the elevation of a celestial body and the time, the device would compute a line of position eliminating a number of mathematical calculations. Unfortunately the unit was very expensive and took up valuable space. Nonetheless, it was very useful for Howard Hughes' 1938 around-the-world flight.