 Complete the following phrase:  Few other navies of the time could hope to exercise much more than local sea control for limited periods, and these vessels were of limited use for shore bombardment in the hands of smaller or less effective operators. Nevertheless, these small vessels with their powerful punch were clearly attractive to the small and medium-size navies of the late 19th century, since they offered the status of big guns without the cost of large warships. This may account for some of the later vessels carrying monstrous 15- and 16-inch guns; flat-irons armed in this fashion were not used for long, probably because their weapons were all but useless except against a stationary target in a flat calm. The defining failure of flat-iron gunboats as coastal defence weapons was in China, where British-built gunboats were used against the French, at the Battle of Fuzhou, and the Japanese, at the 