These look-outs were frequently artificial. Ælian, _de nat. an._, XV. 5, describes a scaffolding consisting of two fir trees between which many cross pieces were fastened. The long ladders still used in Austria and Italy (of which Keller gives an illustration[228]) and the Turkish _dalian_ of the Bosporus represent the modern scaffold. Oppian (_hal._, III. 630 ff.) and Ælian (_de nat. an._, XV. 5) note the enormous hauls made by the fishermen when “the army” of the Tunnies set out on its migrations, company by company. The nets used for the capture of Tunny by the Italians (at the present day) are fixed: made of thick cord, without leads, and sometimes as much as 250 fathoms long, and 15 fathoms deep, thus recalling Oppian’s “a Town of Nets.”[229] Special regard has to be paid now as of old, in fixing their position, to the course frequented by this eminently migratory genus in its annual passage from the Atlantic to the Black Sea and Sea of Azov, a distance of 2800 miles and back again. The same route is always travelled by an ever living stream of undiminished fulness, furnishing food to millions on the Mediterranean. To the Phœnicians and to the Spaniards of old the Tunny ranked high as a commercial asset. The Tyrian tunny was specially prized[230]; its _salsamentum_ travelled far and wide. Rhode (p. 38) points out, however, that this originally was designed not as a delicacy, but as a preventive against scurvy and other diseases attendant on the long voyages which the far-flung commerce of the Phœnicians demanded. The older port, Sidon, got its name from its wealth of fish, which in Phœnician was called _Sidon_,[231] while Tyrus, one of the earliest inhabitants of the younger port, traditionally invented fishing tackle.[232] Many Spanish towns, as their coins attest, notably those of Gades and Carteia, owed much of their prosperity, if not their existence, to the salt or pickled fish trade. Tunny fishing still remains a lucrative industry in the Peninsula.[233] Pliny bears witness to the full stream of Tunny in IX. 2, where he tells us the multitude of the fish which met the fleet of Alexander the Great under the command of Nearchus on one occasion was so vast, that only by advancing in battle line, as on an enemy, was he able to cut his way through: _non voce, non sonitu, non ictu, sed fragore terrentur, nec nisi ruina turbantur_.[234] Faber’s account of the watchman, of the alarm caused by throwing in stones near the inlet through which the shoal of fish has just passed, of the raising of the hue and cry to drive it towards the end of the enclosure, the battering of the fish to death with oars, and of other devices might well pass, although written in the nineteenth century, for a description of the Tunny fishing by an author of the first century.