about eight o'clock in the morning
Strongly impressed with the conviction that this was really what had happened , Simpson , the sailmaker , and I hastened to stock the catamaran with provisions and water enough to last us for four days , and forthwith proceeded to sea , heading in the direction of the island which lay to leeward of us , in the hope of overtaking the two savages before they could arrive at their destination , and inducing them , either by persuasion or by force , to return with us . And we were fully justified in hoping that we should be successful , for the catamaran was a wonderfully speedy craft , especially before the wind ; we calculated that the savages would scarcely average more than four knots per hour paddling in the open sea , even with the wind in their favour , while the catamaran would do ten easily . Consequently we should cover in ten hours a distance which they would need twenty-five hours to traverse ; and , since they would probably not have more than nine hours ' start of us , we ought to catch them long before they could arrive at their island . It was about eight o'clock in the morning when we started , and the moment that we were clear of the reef I bore up dead before the wind ; and thereafter all that was necessary was to keep the catamaran running straight before it . We took it for granted that the fugitives , like ourselves , would avail themselves of the direction of the wind as a guide , consequently we assumed that they were somewhere -- probably about thirty-six miles -- directly ahead of us when we bore away , and a very simple calculation enabled us to determine that , if all our data happened to be correct , we ought to overtake the canoe about two o'clock in the afternoon . Therefore for the first four hours of our pursuit we troubled ourselves only to maintain as straight a course as possible . At the end of that time , however , or about midday -- by which time our own island was out of sight astern , while the other had not yet hove up above the horizon -- I deemed it advisable to take a look round .