Miscellaneous Intelligence. 95 



IV. Miscellaneous Scientific Intelligence. 



1. On the Velocity of Seismic Waves in the Ocean. — Dr. 

 Chables Davison has recently discussed the waves propagated 

 by the Japanese earthquake of June 15th, 1896, the special 

 object being to compare the observed velocity with that calcu- 

 lated from the usual formula, v = ^gh, where h is the depth of 

 the ocean taken as uniform, in which waves would travel with 

 the same velocity as that of the seismic sea-waves. In this case, 

 the epicenter was located some 240 km. east-south-east of Mi- 

 yako, at a depth of 4,000 fathoms. The time of occurrence at 

 Miyako and the surface velocity within the disturbed area being 

 given, the approximate time at the epicenter is obtained, which 

 is assumed to be correct within a minute. 



The earthquake waves were observed at two stations, where 

 self-recording tide gauges are established, — namely, at Honolulu, 

 and at Sausalito in San Francisco Bay. In the case of Honolulu 

 the first effect was observed after an interval of 7 hours 44 

 minutes, a small rise of three-quarters of an inch being noted. 

 The disturbance continued for about 48 hours; at one time a 

 group of seventeen small waves, with an average period of twenty- 

 five and a-half minutes, was recorded. At Sausalito, the first 

 crest reached the gauge after an interval of 10 hours and 34 

 minutes. Here there was a rise of 3*7 inches; later a series of 

 thirty waves, with an average period of six minutes, and a mean 

 distance between crest and hollow of 1*5 inches, were noted. The 

 distance in the two cases was 3,591 and 4,787 miles respectively. 

 From the time-intervals given, the mean velocity to Honolulu is 

 calculated as 681 feet per second, and for Sausalito as 664 feet. 

 The former would give a uniform depth to the ocean between the 

 two points of 14,492 feet; the latter corresponds to 13,778. In 

 the case of the Honolulu line, the depth is very variable, the 

 Hawaiian Islands coming in between the two places ; hence any 

 comparison between the observed and calculated depth is more or 

 less unsatisfactory. In the other case the shortest line joining 

 the two points is free from islands, and cuts the sub-oceanic 

 contour lines nearly at right angles. The mean depth aloug this 

 line is more than 17,000 feet, so that the calculated depth of 

 13,778 feet is only about four-fifths of the measured value. This 

 ratio is the same as that obtained by the author in an earlier dis- 

 cussion, where the calculated depth was 1 900 fathoms and the 

 true depth 2420.— Phil. Mag., Dec. 1900, p. 579. 



2. An Old Indian Village. — An exhaustive account has recently 

 been published by Johast August Udden, of a series of mounds 

 discovered on the west bank of Paint Creek, about a mile and 

 a half south of Smoky Hill river, in McPherson county, Kansas. 



