The ancients relate, that Hercules and Achelous being rivals in the courtship of Deianira, the matter was contested by single combat; when Achelous having transformed himself, as he had power to do, into various shapes, by way of trial; at length, in the form of a fierce wild bull, prepares himself for the fight; but Hercules still retains his human shape, engages sharply with him, and in the issue broke off one of the bull's horns; and now Achelous, in great pain and fright, to redeem his horn, presents Hercules with the cornucopia.
This fable relates to military expeditions and preparations; for the preparation of war on the defensive side, here denoted by Achelous, appears in various shapes, whilst the invading side has but one simple form, consisting either in an army, or perhaps a fleet. But the country that expects the invasion is employed infinite ways, in fortifying towns, blockading passes, rivers, and ports, raising soldiers, disposing garrisons, building and breaking down bridges, procuring aids, securing provisions, arms, ammunition, &c. So that there appears a new face of things every day; and at length, when the country is sufficiently fortified and prepared, it represents to the life the form and threats of a fierce fighting bull.
On the other side, the invader presses on to the fight, fearing to be distressed in an enemy's country. And if after the battle he remains master of the field, and has now broke, as it were, the horn of his enemy, the besieged, of course, retire inglorious, affrighted, and dismayed, to their stronghold, there endeavouring to secure themselves, and repair their strength; leaving, at the same time, their country a prey to the conqueror, which is well expressed by the Amalthean horn; or cornucopia.