Hitherto no means have been pointed out for indicating the approach of an earthquake, as we, by means of the barometer, derive indication of the approach of a storm. This desideratum would, however, now appear to have been supplied. M. Rati-Menton, a gentleman connected with the French diplomatic corps in the Argentine Republic, has recently communicated to the Paris Academy of Sciences, by letter, addressed to the French Minister of Foreign Affairs, a means of learning the approach of an earthquake. According to this gentleman, the earthquake indicator is nothing more than a magnet, to which is suspended by magnetic attraction a little fragment of iron. Shortly before the occurrence of an earthquake, the magnet temporarily loses its power, and hence the uon falls. According to M. Rati-Menton, the accuracy of this indicative sign has been thoroughly tested by a highly educated Argentine officer, Colonel Espinosa, during a residence ol many years at Ariquipa—a region where earthquakes are very frequent. In 1853; 584,200,500 lbs, of cotton were used in england.
This article was originally published with the title "How the Approach of an Earthquake may be Known" in Scientific American 8, 21, 161 (February 1853)