ELECTRO-MAGNETIC SEISMOGRAPH. 425 



it suddenly stopped with a smart sliock. Mr. Ausdell, wlio was a pas- 

 senger, thonglit something had given way on the engine, while Braitli- 

 waite, the driver, thought the stoppage was caused from behind. The 

 train, however, would not move, so the steam was shut off and both got 

 down to examine matters. They could hardly stand on the ground, and 

 at once perceived the true state of the case. 



Earthquakes are very frequent yet, and the people are in a state 

 of panic, a German astronomer, Falb, having predicted our total de- 

 struction on the 30th September or 1st October; while an Englishman, 

 Saxeby, defers the event until the 5th of October. The people are de- 

 serting Arica, and the authorities are making us bring up the custom- 

 house to Tacua. On the railway we can barely keep our work going. 

 In Tacua two-thirds of the population are sleeping in tents. I never 

 before witnessed such a fright. People refuse to transact business until 

 after the 5th of October, or when purchases are made delivery is stipu- 

 lated for after that date. 



Several shocks, and two very severe ones on the 20th and 24th of 

 August, have enforced the German's predictions, and it is becoming 

 heresy to argue against him. The Cordillera is to be the shore of the 

 Pacific. 



The anniversary of the 13th August was a great day in Arica. There 

 were masses and "Veligious processions to prevent a repetition of the 

 great cataclysm, but the people were very anxious, and passed the day 

 on the hill-tops, relieving themselves at intervals by prayer and flying- 

 visits to the taverns. All, however, passed off well. 



THE ELECTRO-MAGNETIC SEISMOGRAPH. 



By Peof. Palmieri, of the University of Naples. 



ITranslated hy B. 0. Duncan, esq., United States consul, and furnished to the Smithsonian 

 Institution by the Department of State.} 



In all the instruments invented up to the present time for registering 

 the movement of the earth's surface, the force itself of the motion of the 

 earth has been charged with the labor necessary for preserving the trace 

 of the shocks ; and this is the reason why slight oscillations of the soil 

 could not be registered. lu the seismograph, which I am about to de- 

 scribe, it is the electric current which performs the labor, and, there- 

 fore, it is possible to have a registering apparatus capable of the great- 

 est precision even for the slightest shocks. It is also possible by means 

 of this apparatus to perceive the register of many vibrations of the earth 

 which would otherwise es(;ape observation. 



Suspended above a small iron cup containing mercury is a fine brass 

 wire coiled into the form of a cork-screw, of about fourteen or fifteen turns. 



