110 



T. C. Mendenhall — Seismoscopes and 



Since their installation these instruments have recorded as 

 follows : — 



At Washington. — From Oct. 6th, 1886, to Nov. 4th, 1887. 



Date. • Time, (75th Mer.) 



h. m. sec. 



October 22, 1886 2 46 14 p.m. 



November 5, 1886 12 27 14 p.m. 



February 23, 1887 7 33 a.m. 



Remarks. 



Felt generally in the vicinity. 



Possibly related to the great 

 Italian earthquake of that 

 time. From the condition 

 of tie instrument before 

 and after the time of the 

 record it was thought to be 

 reasonably certain that it 

 was due to a true seismic 

 disturbance. 



At Teeee Haute. — From Jan. 18th, to Oct. 26th, 1887. 



Time, 90th Mer. 

 h. m. sec. 



February 3d 10 



February 6th 4 



February 10th 11 22 



May 6th. 



May 10th 6 1 



May 24th .10 



August 2d 12 



October 2 2d 6 



27 35 a. m Shocks in Italy, Feb. 3. 



15 6 a. m Shocks in Ind., 111., Ky., and 



Mo. 



27 a. m Papers reported shock at 



Jasper, Ind., but not veri- 

 fied. 



7 45 22 a. m May 3d and 4th, general in 



Mexico and from Texas to 

 Cal. 150 lives lost at 

 Bahispe in Sonora, Mex., 

 also many topographical 

 changes. 



34 p. m Shocks in mountains daily, 



May 12 and 13, shocks in 

 S. C, Cal. and Arizona, 

 May 19 and 20 in Europe. 

 May 30 and 31, in Mexico. 



3 33 a. m.. Shocks felt in Ind., 111., Ky., 



and Tenn., and in Equador, 

 S. A. 



35 43 a. m 



6 35 a. m 



Plan of Campaign. 



In determining upon a systematic plan for the instrumental 

 study of earthquake phenomena, some consideration of the fore- 

 going remarks seems to be demanded, and some useful conclu- 

 sions may be drawn from the brief experience already had. 



In the first place, it is claimed that.time observations are of 

 the first importance and that under the circumstances such only 

 should be undertaken. It is believed that the reasons briefly, 

 and in some degree imperfectly, presented in the foregoing dis- 



