Two methods for measuring the Earth's magnetic field are described. In the former, according to Gauss, the Earth's magnetic field is compared with that of a permanent magnet; in the latter, a well-known method, the comparison is made with the magnetic field generated by a current. As all the used instruments are available off the shelf, both methods are cheap. With some attention to the procedure, both methods give accurate results. (Contains 7 figures, 1 table and 2 footnotes.)