The stream of improvement in naval gunnery began to flow strongly under the administration of Lord Anson. New methods of firing, experiments with priming tubes to replace the primitive powder horns and trains of vent powder, and gun locks to replace the dangerous and unreliable slow match and linstock,[96] were under trial in the fleets commanded by Admiral Hawke, but with results not altogether satisfactory. The locks supplied were lacking in mechanical precision, and the tubes--“very pernicious things” they were voted--were apt to fly out and wound the men. But that the unsatisfactory results obtained were not due to defects inherent in the new devices was soon clearly proved. Twenty years later an eminent gunnery officer, Sir Charles Douglas, by perseverance and an enthusiastic attention to mechanical detail, succeeded in making both locks and priming tubes a practical success, greatly enhancing by their aid the rate and effectiveness of fire of the great guns. Flint-locks of his own design he bought and fitted to the guns of his ship at his private expense. Flannel-bottomed cartridges, to replace the parchment-covered cartridges which had caused so much fouling, and goose-quill priming tubes, were provided by him, and to him is certainly due the credit for initiating the series of improvements in material which, trivial as they may seem in detail, yet in the aggregate had the effect of placing our gunnery at a relatively high level in the ensuing wars. In addition to introducing improvements in methods of firing, Sir Charles Douglas did much to improve the efficiency of the truck carriages themselves. On his appointment to the _Duke_ in 1779 he at once began to put his schemes in hand. To ease the recoil of the guns and to save their breechings he devised and fitted steel springs in some way to the latter; with such surprising good effect (he reported) that even with a restricted length of recoil no breeching, not even that of a 32-pounder weather gun double-shotted and fired over a slippery deck, was ever known to break. The recoil he further eased by loading the truck carriage with shot, which he slung on it, thereby augmenting the recoiling mass. He also proposed and tried another apparatus having the same effect: suspended weights, secured to the carriage by ropes reeved through fairleads, which on recoil the gun was made to lift. Which weights also had an effect in helping to run the gun out again which he calculated to be equal to that of two extra men on the tackles.