126 THE CRATER; them to * get up, as sailors express it. Mark saw the JNeshamony for about a quarter of an hour after she was adrift, though long before the expiration of even that brief period she was invisible for many moments at a time, in consequence of the distance, her want of sail, her lowness in the water, and the troubled state of the element through which she was driving. The last look he got of her was at an instant when the spray was filling the atmosphere like a passing cloud; when it had driven away, the boat could no longer be seen ! Here was a sudden and a most unexpected change for the worse in the situation of Mark Woolston ! Not only had he lost the means of getting off the island, but he had lost his friend and companion. It was true, Bob was a rough and an uncultivated associate; but he was honest as human frailty could leave a human being, true as steel in his attachments, strong in body, and of great professional skill. So great, indeed, was the last, that our young man was not without the hope he would be able to keep under the lee of the shoals until the gale broke, and then beat up through them, and still come to his rescue. There was one point, in particular, on which Mark felt unusual con cern. Bob knew nothing whatever of navigation. It was impossible to teach him anything on that subject. He knew the points of the compass, but had no notion of the variations, of latitude or longitude, or of anything belong ing to the purely mathematical part of the business. Twenty times had he asked Mark to give him the latitude and longitude of the crater; twenty times had he been told what they were, and just as often had he forgotten them. When questioned by his young friend, twenty-four hours after a lesson of this sort, if he remembered the figures at all, he was apt to give the latitude for the longitude, or the longi tude for the latitude, the degrees for the minutes, or the minutes for the degrees. Ordinarily, however, he forgot all about the numbers themselves. Mark had in vain en deavoured to impress on his mind the single fact that any number which exceeded ninety must necessarily refer to longitude, and not to latitude; for Bob could not be made to remember even this simple distinction. He was just as likely to believe the Reef lay in the hundred and twentieth
