  At gravitational interactions of bodies and particles there appears the
defect of masses, i.e. the energy yields since the bodies (or particles) are
attracted. It is shown that this changing of the effective mass of the body (or
the particle) in the external gravitational field leads to changes the
measurement units: velocity and length (relative to the standard measurement
units). The expression describing the advance of the perihelion of the planet
(the Mercury) has been obtained. This expression is mathematically identical to
Einstein's equation for the advance of the perihelion of the Mercury.
