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.
We can say that Every transducer is also(or has) a sensor but every sensor need not be a transducer. Sometimes it is. A compass is a simple sensor of magnetic north, wherein the magnetic element in the compass is the transducer Hope this helps. If there is anything wrong in my explanation, do comment/suggest. I'm happy to learn and happy to help :)