ON SEISMOLOGICAL INVESTIGATION. 195 



1891; December 2, 1891; January 19, 1892; October 15, 1892*; March 20, 1893* 

 September 1, 1893*; March 24, 1894*; July 23, 1894*; November 1, 1894 

 November 10, 1894; November 15, 1894; January 7, 1895: February 9, 1895* 

 October 10, 1895*; December 13, 1895*; December 18, 1895*; July 9, 1896* 

 August 6, 1896* ; October 8, 1896* ; May 5, 1897.* 



In the above li.st the thirty-one interruptions marked with an asterisk 

 took place whilst horizontal pendulums were in operation in or near 

 Europe. 



The European observations were as follows : — 



September 18, 1889. At Potsdam, 6-92h. to 9-3h., there was a large disturbance, 

 which suddenly became great at 7-87h. At Wilhelmshaven the disturbance lasted 

 from 7h. to 9-5h. The origin is unknown. 



September 5, 1889. At Potsdam there was a heavy disturbance at 22-67h., with 

 a sudden increase at 2308h. At Wilhelmshaven similar phases are at 22-5h. and 

 2308h. Large disturbances also with unknown origin were noted on August 29 at 

 18-48h. 



October 9, 1892. At Strassburg and Nicolaiew, at about 2-45h. and 2 70h. 



March 3, 1891. At Tenerifife, earthquake at l-79h. Origin unknown. 



May 2], 1889. At Potsdam, a heavy disturbance at 10-55h. to U-lh. Origin 

 unknown. 



March 20, 1893. At Strassburg and Nicolaiew, at 5-18h. and 5'27h. At this 

 time there was an earthquake in Catania. 



October 13, 1892. In Strassburg 1707h. to ]7-78h. An earthquake on the 

 Donau. 



September 1, 1893. At Charkow at 9.35 A.M. 



February 12, 1894. At Charkow, a strong disturbance at 1.35. 



March 24, 1894. At Charkow, about this time, exceedingly heavy disturbances 

 were recorded. From 17h. 35m. on the 21st to 2h. 48m. on the 22nd ; from 9-35h. on 

 the 22nd to 3-35h. on the 2.3rd ; and on the 24th, from Oh. 26m. to Ih. 2m. 



July 22, 1894. At Charkow, from ll-35h. to 17-35h. 



October 9, 1895, at 13h. 26m. Slight. 



July 8, 1896, at 14h. 54m. and 17-46. At Shide. 



October 6, 1896, at 21-51b. At Shide. 



May 5, 1897, at 10-44h. At Shide. 



December 2, 1896, at 10 to 11 a.m. At Shide. 



Inasmuch as two of the interruptions took place on May 22, 1889, 

 find two on September 1, 1893, which closely correspond with the unfelt 

 but heavy earthquake in that year, we may say that out of twenty-nine 

 interruptions sixteen of these have approximately coincided with the times 

 at which earthquakes with unknown origins have been recorded in Europe. 



Because on the Para — Maranham ^ section interruptions have been 

 frequent in October, November, and December, and on the Maranham — 

 Ceara section in November and in March, in searching for the cause of 

 these interruptions we should look to variations in ocean currents or 

 phenomena with a seasonal change. 



IFest Coast of Europe and Africa. 



Mediterranean Lipari — Milazzo Sea. — December 1, 1888 ; March 30, 

 1889* ; September 15, 1889* ; February 9, 1893.* 

 Zante—Canea.—Kaxch. 29, 1885. 



' ' The Para — Maranham cable is, I believe,' a friend writes me, ' laid on a 

 shallow muddy bottom, the mud being so fluid that it is .said that a schooner with 

 a fair wind can make a good passage when half in mud and half in water.' If this 

 is so, then the Amazon floods may have much to answer for in connection with 

 cable-interruption. 



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