Ford has beaten General Motors for the first time in nearly a century, in terms of number of US factory workers. Ford has 50,703 to GM's 50,300 or so.
Answers. Well, the simplest answer is that the astrolabe pretty well had to be used at night and could not be used in bad weather. The compass, which relys on the magnetic field of the Earth rather than a visualiztion of the stars, works at any time, and in any weather.
On small vessels the compass is usually located in front of the helm position. Care should be taken to ensure the compass is installed far enough away from structural members, equipment and instruments such as radios, speakers, engine rev counters (tachometers), etc, which can produce strong magnetic fields.