His next posting, starting 25 September 1879, was to as Flag Captain to Sir Leopold McClintock, commanding the North American squadron. "Northampton" was a new ship with a number of innovations, including twin screws, searchlights and telephones, as well as being armed with torpedoes. It was fitted with an experimental Thomson-designed compass, which the inventor was on hand to adjust. Three days were spent attempting and failing to adjust the compass, with Thomson becoming increasingly bad tempered, until it was noticed that by accident the degree card had been marked with only 359 instead of 360 degrees. The ship was fitted with a new design of lamp created by Captain Philip Colomb, who came on board to inspect them. As a joke, Fisher arranged for anything that could go wrong with the lamps to do so, sending Colomb away disheartened over his invention (although Fisher officially reported favourably about the lamps). On another occasion, the naval hospital at Halifax requested some flags to fly for the Queen's birthday. Fisher obliged, but sent only yellow and black flags signifying plague and quarantine. On the other hand, he worked hard at improving his ship. As reported by his second in command, Commander Wilmot Fawkes, the ship carried out 150 runs with torpedoes in a fortnight, whereas the whole rest of the navy performed only 200 in a year.