In his very circumscribed experience when a young man he had seen whales, but they had generally been a long way off; and as the old-fashioned method of rowing after them in boats had even then been abandoned in favor of killing them by means of the rifled cannon, Captain Hubbell had not seen very much of these creatures until they had been towed alongside.

But now he could study whales at his leisure.

It was seldom that he had to wait very long before he would see one near enough for him to examine it with a glass, and he never failed to avail himself of such opportunities.
The consequence of this constant and careful inspection was the conclusion in Captain Hubbell's mind that there was only one whale in the polar sea.

He had noticed, and others had noticed, that they never saw two at once, and the captain had used his glass so often and so well that one morning he stamped his foot upon the deck and said to Sammy: "I believe that's the same whale over and over and over ag'in.

I know him like a book; he has his ways and his manners, and it isn't reasonable to suppose that every whale has the same ways and manners.