Under the terms of a treaty made at Paris in 1773, United States produce for British West Indian ports could only be carried by British subjects in British ships. Britain's men-of-war were also authorized to seize any vessel laden with produce for or from any French colony. Brock was a soldier, not a policeman, and coast-guard duties palled upon him. His great diversion was in calculating the probabilities of invasion by the French. In expectation of this, the refortifying of the island was in progress. The memory of Admiral d'Estaing's visit with his fleet from Toulon, and the capture of St. Vincent, sent a chill through the island. The great victory by the British Admiral Rodney, when he whipped a superior French fleet to a standstill, was yet to come. Bastions and earthworks grew during the night like mushrooms. While Brock chafed under restraint, he knew how to improve the opportunity. Fishing, shooting sea-fowl, and exploring the interior on horseback, were Brock's chief pastimes. He became a fearless horseman. Mount Hillaby rose 1,200 feet above the Caribbean Sea. The very crest of its almost impossible pinnacle Brock is said to have ascended on horseback. Between Bridgetown, in Barbadoes, and Kingston, Jamaica, he divided his time, and though monotonous, his life in the Windward Islands was not wholly void of adventure. Shortly after joining his regiment at Bridgetown our hero had his first affair of honour, an opportunity to display his courage under most trying conditions. A certain captain in the 49th was a confirmed duellist, with a reputation of being a dead shot at short range. Resting upon his evil record, this braggart had succeeded in terrorizing the garrison, and it was soon Brock's turn to be selected for insult. But Isaac could not be bullied or intimidated. He promptly challenged and was as promptly accepted. The fateful morning arrived. In a lonely spot, palm-sheltered, and within sight of the sea breaking upon the coral reefs, principals and seconds met. There was no question in Brock's mind as to his duty--the duello at that time was the recognized court of appeal. If its purpose as originally designed had at times been infamously abused, it was still the one and only arbiter through which insults had to be purged and from which, for the "officer and gentleman," there was no escape.