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the almanacs, will not answer to set our watches by for standard time, unless we are on one of the standard meridians. One difference between these two kinds of time is that local time varies continuously as we travel east or west, while standard time varies only by jumps of one hour when we cross the boundaries of any of the four zones just described.

Midnight, like noon, is continually travelling round the earth, crossing all the meridians in succession. At every crossing it inaugurates the beginning of another day on that meridian. If it is Monday at any crossing, it will be Tuesday when it gets back again. So there must be some meridian where Monday changes to Tuesday, and where every day changes into the day following. This dividing meridian, called the "date line," is determined only by custom and convenience. As colonization extended toward the east and the west men carried their count of days with them. The result was that whenever it extended so far that those going east met those going west they found their time differing by one day. What for the westward traveller was Monday was Tuesday for the eastern one. This was the case when we acquired Alaska. The Russians having reached that region by travelling east, it was found that, when we took possession by going west, our Saturday was their Sunday. This gave rise to the question whether the inhabitants, in celebrating the festivals of the Greek Church, should follow the old or the new reckoning of