There was a feature of the carronade, however, which if it had been exploited might have made the story of the carronade much longer: might, in fact, have made the carronade the starting-point of the great evolution which ordnance was to undergo in the second quarter of the nineteenth century. We refer to the large area of its bore, as rendering it specially suitable for the projection of hollow spheres charged with powder or combustibles: in short, for shells. Although, as shown by the inscription on the model presented to him, General Melville’s invention covered the use of shell and carcass shot, yet there was no general appreciation in this country, at the time of its invention, of the possibilities which the new weapon presented for throwing charges of explosive or combustible matter against the hulls of ships. Empty hollow shot were tried in the original Smasher for comparison against solid shot, in case the latter might prove too heavy;--and these, as was pointed out by an eminent writer on artillery,[89] possessed in an accentuated degree all the disadvantages of the carronade system, their adoption being tantamount to a reversion to the long-exploded granite shot of the medieval ordnance--but the use of _filled_ shell in connection with carronades does not appear to have been seriously considered. The disadvantages of filled shell as compared with solid shot were fairly obvious; their inferiority in range, in penetrative power, in accuracy of flight, their inability to stand double-shotting or battering charges--all these were capable of proof or demonstration. Their destructive effect, both explosive and incendiary, as compared with that of uncharged shot, was surprisingly under-estimated. Had it been otherwise, the carronade principle would have led naturally to the introduction of the shell gun. “The redeeming trait in the project of General Melville,” wrote Dahlgren, “the redeeming trait which, if properly appreciated and developed, might have anticipated the Paixhans system by half a century, was hardly thought of. The use of shells was, at best, little more than a vague conception; its formidable powers unrealized, unnoticed, were doomed to lie dormant for nearly half a century after the carronade was invented, despite the evidence of actual trial and service.” In other respects the carronade did good service in the development of naval gunnery. Its introduction raised (as we have seen) the whole question of windage and its effects, and was productive of general improvement in the reduction and regulation of the windage in all types of gun. By it the advantages of quick firing were clearly demonstrated. And by its adoption in the ship-of-the-line it contributed largely to bring about that approach to uniformity of calibre which was so marked a feature of the armament schemes of the first half of the nineteenth century. CHAPTER VI THE TRUCK CARRIAGE