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 its descent was accomplished, the great luminary would steal above the horizon, there to continue for a period of six months until the commencement of the ensuing winter. Indeed, the actual duration of apparent summer would be somewhat protracted in consequence of the effect of refraction in raising the sun visually above the horizon when in reality it was still below. The result would be to lengthen the summer at one end and to anticipate it at the other. Such would be the astronomical conditions at the North Pole; that anomalous point, from which every other locality on the globe lies due south, that mysterious point which up to the present never seems to have been approached by man within a distance less than 400 miles, unless, indeed, as is not improbably the case, the Pre-glacial Man who lived in the last genial period found a temperate climate and enjoyable conditions even at the latitude of 90°.

For our present purpose it will be necessary to get a very clear idea as to the precise point on the earth which we mean when we speak of the North Pole. As our knowledge of it is almost entirely derived from astronomical phenomena it is necessary to assign the exact locality of the Pole by a strict definition depending on astronomical facts. Supposing that Nansen does succeed in his expedition, as every one hopes that he will, and does penetrate within that circle of 400 miles' radius where the foot of civilized man has never yet trod, how is he to identify that particular spot on this globe which is to be defined as the North Pole? It was for this purpose that at the commencement of this paper I referred to that photograph of the concentric circles which illustrated so forcibly the position of the Pole in the heavens.