80i THE WANDERINGS OF THE NORTH POLE. 



Pole in tlie sky was, therefore, so different in the time of the Pharaohs 

 from the North Pole in the time of Victoria, it is proper to ask whether 

 there was a like difference, or any difference at all, between the terres- 

 trial pole at the time of the building of the Pyramids and that terres- 

 trial pole in whose quest IS'ai I sen is just setting off. If Pharaoh had 

 despatched a successful exi)edition to the North Pole and driven a post 

 in there to mark it, and if Nansen were now successful, would he tind 

 that the North Pole in the earth which he was to mark occupied the 

 same position or a different i)osition from that which had been discov- 

 ered thousands of years previously ? At first one might hastily say 

 that there must be such a difference, for it will be remembered that I 

 have defined the North Pole in the earth as that point through which 

 the tube i)asses which would permit an eye placed at the center of the 

 earth to view the North Pole in the sky. If, therefore, the North Pole 

 in the sky had undergone a great change in its j)osition, it might seem 

 obvious that the tube from the earth's center to its .surface which would 

 now conduct the vision from that centre to the north celestial pole 

 would emerge at a different i)oint of the earth's crust from that which 

 it formerly occujned. We have here to deal with the case that arises 

 not uufrequently in astronomy, in which a fact of broad general truth 

 requires a minute degree of qualification ; indeed, it is not too much to 

 say that it- is in this qualification of broad general truths that many of 

 the greatest discoveries in i>hysical science have consisted. And such 

 is the case in the present instance. There is a broad general truth and 

 there is the qualification of it. It is the qualification that constitutes 

 the essential discovery which it is my object herein to set forth. But 

 before doing so it will be necessary for me to lay down the broad gen- 

 eral truth that the North Pole of the earth as it existed in the time of 

 the Pharaohs appears to be practically the same as the North Pole of 

 the earth now. It seems perfectly certain that at any time within the 

 last ten thousand years the North Pole might have been found within 

 a region on the earth's surface not larger than Hyde Park. Indeed, 

 the limits might be drawn much more closely. It is quite possible that 

 many an edifice in London occupies an area sufliciently great to cover 

 the holes that wonld be made by all the posts that might be driven to 

 mark the precise sites of the North Pole on the earth not only for the 

 the last five ov ten thousand years, but probably for periods much 

 more ancient still. It is very likely that the North Pole at the time of 

 the glacial epoch was practically indistinguishable from the North 

 Pole now; in fact, the constancy, or sensible constancy I should, per- 

 haps, rather say, of the situation of this most critical point in our globe 

 is one of the most astonishing facts in terrestrial physics. 



Let us, then, assume this broad general fact of the i)ermanency in 

 the position of the North Pole, and deduce the obvious consequences it 

 implies with regard to the earth's movement. At this point we find 

 the convenience of the time-honored illustration in our geography books 



