one o'clock
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 . However , I was quite certain that a run of another half-hour would suffice to bring her into view , therefore at one o'clock I again ascended to the masthead , quite prepared to see her directly ahead . But again I was disappointed , for the horizon was bare in every direction , save for the fact that , as straight ahead of us as though we had seen and been steering for it all the while , there was a delicate blue shape , which I instantly recognised as the upper part of the island that we had seen from the lip of the crater on our own island . I was decidedly nonplussed at the fact that the fugitives were still invisible , and knew not how to account for it . True , the sea was a trifle heavy for navigation in so frail a craft as a small canoe , yet the two savages were experts in the handling of such craft , and it was therefore scarcely likely that they had met with a mishap of any description -- indeed , all that was needed to ensure their perfect safety was to keep the canoe dead before the sea , and she would go along without shipping a drop of water ; even I , comparatively inexpert as I was , would not have hesitated to undertake such a voyage , under the influence of so powerful an inducement as that which we suspected to animate the two natives .