Again, much yarn in the North is spun upon mules, while in the South these machines are uncommon.
For certain purposes, this soft but fine and even yarn is indispensable.
Only strong, highly skilled operatives, usually men, can tend these machines.

The earnings of such specialists cannot fairly be compared with the amounts received by ordinary girl spinners on ring frames.

Again the weekly wage of an expert weaver upon fancy cloth cannot justly be compared with that of a Southern operative upon plain goods.

Where the work is comparable, however, the rates per unit of product in North and South are not far apart.
From the standpoint of the employer it may be possible that the wages per unit of product are higher in some Southern mills than in some New England establishments.

In the case of an expensive machine, an operative who gets from it only sixty to seventy-five per cent of its possible production may receive higher wages, or what amounts to the same thing, may produce at a higher cost per unit than a more highly paid individual who more nearly approaches the theoretical maximum production of the machine.