404 ARCTIC AND ANTARCTIC REGIONS 



Similarly, if we repeat this eastward movement, Wednesday will begin two 

 hours too soon ; and so on, until, when our starting point is reached, we shall, 

 in count of days, be just twenty-four hours ahead in our reckoning. The 

 result will be that, instead of ending the journey in twenty- four days (as we 

 seem to do) and on a Wednesday, we shall actually complete it in twenty- 

 three days, and on Tuesday. On the dther hand, if we move westward in 

 this way the reverse will happen; our da)^s, as measured from noon to noon, 

 will be twenty-five hours long, and we shall actually complete the trip in 

 twenty-five days and on Thursday. For the stay-at-home, and for travelers 

 returning thus from the east and from the west, there will, accordingly, if 

 no correcti(5h is made in the reckoning, be for each day three distinct dates, 

 each perfectly correct by diary or log; and each day of the week, not Sun- 

 day simply, will be repeated thrice. 



EASTWARD AND WESTWARD CURRENTS OF CIVILIZATION 



MEET. 



This shifting of dates is, of course, the same in the end whether the 

 journey about the earth be made in a month or in a thousand years ; and, in 

 reality, it has become of practical interest principally in connection with move- 

 ments of population which have extended through centuries. From Europe 

 as a center the leaders of modern exploration advanced toward both the west 

 and the east; and in their footsteps colonists have followed establishing new 

 centers of civilization, whose commercial intercourse with Europe has in 

 general been maintained along the routes of the earliest exodus. But the 

 colonists carried their European dates with them ; and it has thus happened 

 that at all the points— chiefly in the islands of the Pacific Ocean — where the 

 east-ward has met the westward current of colonization and commerce, there 

 has arisen a conflict of dates identical with that just explained. On the one 

 hand lies regions where the time reckoning has lagged behind ; o^ the other, 

 regions where it has shot ahead. An imaginary line drawn upon the surface 

 of the globe separating the regions where this difference in dates prevails is 

 a date-line; and it is clear that the difference of reckoning marked by each 

 line is, in general, one day, for when two circumnavigators, starting in oppo- 

 site directions from one place, meet one another in the journey, one will have 

 lost just that part of a day which the other has not yet gained. On the 

 eastern side of the line, namely, the date will be one day earlier than on the 

 western side ; that is, if it is Sunday on the former it will be Monday on the 



