Earthquake waves start out from the great area where the cataclysm took place, and begin to disturb the earth in all directions, just as if we were to put a row of marbles on a table and were to strike the end marble of the row. The marble farthest from it would presently receive the shock as it travelled along the row of marbles. Any one of our readers who has ever seen a train of luggage wagons being shunted is familiar with the way in which the shock of a sudden pull or push on the part of the engine travels all down the line of wagons, and we may think of the shock of an earthquake as travelling along and through the earth in the same way. Observation, however, shows that these waves are propagated farthest in one particular direction. For example, the chief movement following the San Francisco earthquake, which originated from fault lines running parallel to the coast of California, was much more marked in countries lying to the east or west of California than in countries lying towards the south. England and Japan obtained large records of the disturbance, while in Argentina the records were extremely small. In the case of the Jamaica earthquake, where the lines of origin ran east and west, the phenomenon was reversed. Toronto received a large quantity of motion, and England a very little. Another peculiarity of this phase of earthquake motion is that it may be propagated in one direction round the world to a greater distance than in an opposite direction. The suggestion is that the initial impulse was delivered in the direction towards which motion was propagated farthest. That which happens corresponds to what we see if we dip the blade of a spade in water and suddenly push the blade in some particular direction. The water waves thus created travel farthest in the direction of the impulse. Another curious phenomenon connected with the large waves of certain earthquakes is that they may be very marked for one thousand miles round their origin, and may be perceived on the exactly opposite side of the earth (though, of course, much reduced in size), but cannot be recorded on the earthquake instruments of the regions in between. For example, an earthquake originating near New Zealand may be recorded in that country, but not in India, Egypt, West Asia, or east of Europe, though in Britain it may make itself evident on the seismometer's record. The phenomenon may be compared to a water wave running down an expanding estuary. At the mouth of such an estuary it may have become so flat that it is no longer recognisable. Should it, however, run up a second estuary, we can imagine concentration taking place, so that near the top of the second estuary it would eventually become recordable on instruments. In these antipodean survivors we see the final efforts of a dying earthquake. It is only occasionally that the precursors and the followers of these large waves have sufficient energy to reach their antipodes. They die _en route_.