ABSTRACT
Sir John Herschel suggested changes in the eccentricity of the earth's orbit as another possible explanation, Lagrange having indicated an oscillatory change, subsequently established by Le Verrier, in the shape of the earth's orbit from an ellipse to a circle. The first geographers were astronomers, Ptolemy for instance, and all fundamental 'large scale' geography, such as the determination of the earth's size and shape by measurement of meridian arcs, has been for centuries in the hands of astronomers. In fact, the fundamental problems in all extensive surveys, as well as in navigation or oceanography, are the determination of the latitude, and longitude, whose accurate determination is so important. With the strong support of America, Greenwich obtained a large majority of the votes at a special International Conference, and by the present time nearly all civilised countries have fallen into line, so that Spain, for instance, has adopted Greenwich time, and Eastern China eight hours fast on Greenwich.
