 Jones also recognised that the development of more powerful and accurate artillery made the old system of shoreline batteries extremely vulnerable. He proposed that the shoreline artillery should be pulled back some 300 yards (270 metres) to "retired batteries" situated higher up the hill, equipped with the latest and most powerful guns and firing from barbettes rather than through embrasures. Such positions could not easily be seen from the sea, were out of the effective range of enemy ships and could not be flanked by landward guns. The sea wall would be defended solely by musket fire with the artillery support being provided from the bastions and retired batteries.
