De proiectione geographica de Lisliana in mappa generali imperii Russici usitata

ON THE GEOGRAPHICAL PROJECTION

OF LISLE

USED IN THE GENERAL MAP OF THE RUSSIAN EMPIRE.

L. EULER.

When the question was once raised as to which method of projection should be used in constructing a general map of the Russian Empire, the Stereographic projection—by which both terrestrial hemispheres, that is to say the upper and the lower, are usually represented—presented itself first; because in this way, not only would all circles of latitude be intersected normally by the meridians, but all small portions would also be shown in similarity to their appearance on the spherical surface. And at that time, Hasius, a most excellent geographer and Professor at Wittenberg, also used this method of projection in drafting the general map of this Empire.

§. 2. In truth, two significant disadvantages were soon observed in this projection, which were most contrary to the proposed goal. Firstly, in the middle meridian, the degrees of latitude are too unequal, being twice as small near the Equator as they are near the poles; from this, the huge disadvantage arose that for regions situated near the edges of this map, the scale of miles would turn out much larger than for the regions shown in the middle of the map; wherefore, to an observer of the map, a Province—for example, Kamtchatka—would appear almost four times larger than a Province of the same size represented in the center of the same map.