On the possibility of terrestial tests of general relativity theory

The method for detecting effects of general relativity theory showing in the influence of gpeat gravitational maSses on the atomic clock rate (on the maser frequency) in two cases: a) when one maser is installed on the earth and another similar one on the artificial satellite; b) when two identical masers are installed at opposite ends of earth's diameter is proposed. It is noted that the atomic clock rate accuracy existing at that time (1957) is not enough for observing relativistic effects. It is considered that their detection reqUires the clock rate accuracy of about 10-19