Which preposition to use with cobs

with Occurrences 2%

Beside the door stood two stout cobs with broad soft-padded saddles, well fitted for easy traveling, and speaking of rich guests in the parlor.

at Occurrences 1%

According to a tradition current among the Miamis, one year when there was an unusual abundance of corn, the spirit of the corn was very angry because the children had thrown corn-cobs at each other in play, pretending to have suffered serious bodily injury in consequence of their sport.

on Occurrences 1%

Then presently they met three merry minstrels, all clad in red, who stared amain to see a Gray Friar with such short robes walking in the middle of the road, and two brothers with heads bowed with shame, riding upon richly caparisoned cobs on the footpaths.

Which preposition to use with  cobs