i. The angle that one meridian on the earth's surface makes with another. See
convergency (i).
ii. The angle between two meridians at a given latitude. At the poles, its value is the change of longitude, but it slowly reduces toward the equator when the value is zero, as meridians become parallel to one another. Earth's convergence is the change of longitude multiplied by the sine of the latitude. See
convergency (ii).
iii. The difference between the great-circle bearing of two meridians. It is equal to the change of longitude (ch long) λ sine latitude. See
convergency (iii).
iv. Also called
convergency.