Also
may be neglected.
We shall then have
The weight W₀ refers to the height h₁ the lower of the two stations. At the surface of the earth, this weight would be greater in the ratio of
. But as h is always small compared with R this correction may be neglected.
But there is another of more importance which should be taken into account. On account of the spheroidal form of the globe weight varies with the latitude. If G represent the weight of a body at latitude 45°, then at any other latitude l, its weight, is found by multiplying G by
