The figure denoting the general average yield per acre of any class of crop needs readjustment after every successive harvest.
In coinage it is one of the commonest units in early times; from Phoenicia, round the coast to Macedonia, it is predominant (17); at a maximum of 230 (Ialysus), it is in Macedonia 224, but seldom exceeds 220 elsewhere, the earliest Lydian of the 7th century being 219, and the general average of coins 218.
Are sometimes grown, amounting occasionally to loo tons per acre, the general average yield of 184 tons is about 5 tons more than that of turnips and swedes.
The eccentricity of the ellipse is in the general average about 0.055, whence the moon is commonly more than i' further from the earth at apogee than at perigee.
We have strong reason to believe that even the sun, though much denser than the general average of the stars, may possibly be characterized as gaseous rather than solid.
Again, although from the richest old permanent meadow-lands very heavy crops of hay are taken season after season, the general average yield of permanent grass is about 3 cwt.
The general average yields of the corn crops are not fairly comparable one with the other, because they are given by measure and not by weight, whereas the weight per bushel varies considerably.