He designed the Mercator Projection in 1569 strictly to help navigators; his is the only projection that shows rhumbs as straight lines: a navigator could connect two ports with a straight line
on Mercator's map and then proceed along a
constant course
based on the
direction of this line.
In fact, the finished script by David Giler (Undisputed, The Money Pit) and Walter Hill (48 Hrs., The Getaway), the team who produced Alien and co-wrote Aliens, was constantly revised with the help of screenwriter Larry Ferguson (Highlander, Rollerball), with
directions in the plot changing
on a
constant basis during the shoot, mostly prompted by studio meddling.