about midday
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 . Accordingly , turning over the steering paddle to Simpson , I shinned up to the catamaran 's masthead , and remained there for fully five minutes , intently scrutinising the surface of the sea in every direction , my range of vision at that elevation covering a circle of about nine miles radius . But there was nothing in sight , at which I was in nowise surprised , as I estimated that the canoe was still about twelve miles ahead of us . I calculated , however , that we were gaining upon her at the rate of about six miles an hour , in which case she ought to be on the horizon 's verge in the course of another half-hour ; therefore at the expiration of that time I again went aloft , and was just a trifle disappointed to find the horizon still bare .