From far away New Zealand, on the same date, the government seismograph at the capital, Wellington, recorded seismic waves that apparently passed round the earth five times at intervals of about four hours each.
Across the Atlantic, at Heidelberg, in Germany, the records showed vibrations lasting one hour. At Sarayevo, in Bosnia, there was a sharp shock at 11 A. M., undulating from west to east. At Funfkirchen, in Hungary, at Laibach, in Austria, in the Isle of Wight, off the coast of England, and all through Italy, from north to south, the shocks were felt.
At Hancock, Mich., a shock was felt on April 19th a mile below the surface in the Quincy mine of such severity that one man was killed and four injured by a fall of rock loosened by the trembling of the earth. There is no evidence, however, that this had any connection with the California disaster, the dates not coinciding.
Turning to the Far East, across the Pacific, seismographs in the Imperial University of Tokio showed that the earthquake was felt there eleven minutes later than in San Francisco, and similar instruments in Manila detected the arrival of the seismic waves twenty minutes after the San Francisco shock. In this there was a slight difference in time compared with Tokio, but, considering the distance, near enough to prove that the disturbances came from the same source.
Not until the day following was any noticeable disturbance felt in Honolulu, but on April 19th shocks were plainly felt for six minutes and the water in the harbor rose rapidly. Panic seemed imminent just before the shocks subsided. While earthquakes are by no means infrequent in these islands, this was more severe than any recorded in recent years, causing buildings to sway to and fro and partly demolishing some of frail construction.
If, as the majority of men qualified to discuss earthquakes seem to think, the San Francisco earthquake had no connection with volcanic action, but was caused by what is technically known as a “fault” in the formation of the crust of the earth, it seems easy enough to account for these wave motions travelling round the earth. How widely this may really have made itself felt it is not possible to say. Several of the great earthquakes in Japan have been recorded in the seismographs of the observatories on every continent and in Australia, showing that in severe disturbances of this kind the whole surface strata quiver, alike under the oceans and over the continents and islands. At the time of a shock, of course, half of the world is in darkness and asleep. This is taken to account for the fact that so far only a few observatories have reported catching the San Francisco vibrations.
The instruments invented for the recording of the motions of the earth’s crust are looked upon by scientists as the most delicate of all machines. So highly sensitive are they, indeed, that the very slightest vibratory motion is recorded perfectly. Even the tread of feet cannot escape this instrument if sufficient to cause a vibration.