226 REPOKT— 1887. 



tbat the greater number of tremor disturbances are phenomena which 

 originate upon the surface of the earth, and it is not necessary to look to 

 subterranean agencies for their production. That tremors are produced 

 by local winds acting upon trees and buildings is a phenomenon hardly 

 requiring demonstration. We also know that artificially produced tremors 

 can be propagated through ordinary soil to a considerable distance. 

 Vibrations produced by stamping with the feet can be seen reflected in a 

 dish of mercury at the distance of 100 feet. The vibrations produced 

 by a railway train can be recorded at the distance of a mile. 



The question now is whether winds blowing against high mountains, 

 which at times, as I showed in my report for 1885, are in a state of 

 vibration, produce a disturbance sufficiently iiitense to be felt at the 

 distance of 100 miles upon plains where it is practically calm ? 

 Observations, so far as they have gone, appear to indicate this to be 

 the case, and if it is so, then the movements of the ocean upon which 

 wavelets and waves outrace the storms which originate them find a 

 parallel in the movements of the land. 



As a test of the accuracy of my conclusions I invited Colonel H. S. 

 Palmer, R.B., to determine from a series of weather maps (267 in all) 

 the days upon which tremors had occurred. The rules for his guidance 

 were : — 



1. With a general calm in Central Japan tremors seldom occurred. 



2. With a wind in Tokio and Central Japan, or with no wind in 

 Tokio, but with strong wind in other parts of Central Japan, tremors 

 might be observed. 



On receiving Colonel Palmer's list 1 was agreeably surpi'ised to find 

 that in 54 out of b7 cases ivheii he reported that tremors ought to have been 

 observed he was absolutely right, there having been tremors which were very 

 marked. In reporting ' no tremors ' he was only wrong when slight 

 tremors had occurred. 



Report of the Committee, consisting of Mr. H. Badeeman, Mr. F. 

 W. KuDLEU, Mr. J. J. H. Teall, and Dr. Johnston-La vis, /or the 

 i/nvestigation of the Volcanic Phenomena of Vesuvius and 

 its neighbourhood. (Drawn up by H. J. Johnston-Lavis, M.D., 

 F.G.S., Secretary.) 



Fewer changes have taken place in Vesuvius than the reporter has known 

 to occur during any of the eight years the volcano has been under his 

 observation, and even in the recent history of the mountain no such 

 extent of regular action is indicated. The lava mentioned in the last 

 report as flowingr continued to do so in varying quantity, and about 

 September 17, 1886, again reached the cultivated lands, destroying some 

 trees at the southern end of the Sorama ridge. During the latter part of 

 the same month and the first half of October the amount of lava varied 

 very much, as also did the activity. Sometimes after a few days of quiet- 

 ness with the lava high in the chimney so that the scoria stage persisted, 

 a small cone of eruption would be built up at the bottom of the great 

 crater formed during the summer ; but as soon as greater activity declared 

 itself, or the lava-level sank, the ash-forming stage prevailed, and the 

 great crater formed during the summer was further enlarged. As all 



