96 REPORT— 1895. 



periods o£ steadiness when the diagrams were practically straight lines 

 happened at the same time, and because the large or small movements of 

 A have agreed in time with the large or small movements recorded ):)y E. 

 As illustrative of this synchronism, the movements of these instruments 

 between February 15 and February 25 have been plotted as curves (see 

 Plate IV.). 



Once or twice it will be observed that crests of waves have been 

 reached after midnight or in the morning, which agrees with the results 

 published in 1893 (Thirteenth Report). In the majority of instances, 

 however, this has been reversed, and the movement of the pendulum in 

 one direction has been completed at any time between 4 p.m. and 10 p.m., 

 and it has returned to its original position between 5 a.m. and 10 a.m. 

 Because the waves on the original diagrams are long and flat it is usually 

 difficult to determine with any accuracy the exact time at which an 

 excursion in any one direction has been completed. Sometimes the boom 

 has remained at rest at one of its limits for five or six hours before the 

 return journey has been commenced. The movement from 5 or 10 a.m. 

 until 4 or 10 p.m. has nearly always been quicker than the return motion 

 during the night. 



The amplitude of motion does not seem ever to have exceeded 3''-00. 

 In 1893 I described movements of from 2"'00 to 10'''00 ; but these which 

 I now discuss are the result of observations with several instruments, 

 although I cannot answer for any great degree of accuracy, I am inclined 

 to consider the new determinations as being nearer the truth. The move- 

 ments of E, which is underground, have usually been greater than tliose 

 ]-ecorded by A in my house. In a few instances, however, the deflections 

 of A have been the greater. 



As an appendix to the table on p. 97 short abstracts from my journal 

 are added : — 



(i) Extract from Journal of Records obtained in 1894. 



In the following extracts the sensitiveness of the instruments means 

 the angular tilting required to produce a deflection of one millimetre of 

 the points at the end of the booms. These degrees of sensitiveness for 

 the instruments E, A, and F are given in fractions of seconds of arc- 

 immediately after the date. 



January 24-27 (0''-18, 0"-23, 0''-43).— From the 24th to the 25th E 

 showed a rapid S.E. lifting of 3" when the light spot left the film. A small 

 earthquake occurred at 10.48 a.m. on the 25th. From the 25th to the 27th 

 there was a S.E. lifting of l"-62. Daily waves of l"-44 and l"-26 are 

 well marked. All instruments showed tremors, but they are most marked 

 underground on E, where they reach 12 mm. .On A and F the daily waves 

 are hardly visible. 



January 27-30 (0"-19, 0"-23, 0"-18).— E moved 5"-32, and the light 

 spot left the film. It shows tremors reaching 14 mm. A and F agree 

 in showing a N.E. lifting, but the daily wave is only seen on A when 

 the tremors reach 10 mm. The tremors are most pronounced under- 

 ground. 



January SO-February 2 (0"-43, 0"-23, 0"-18).— E shows similar 

 characters to A and F, that is, the trace is at first straight, and then two 

 daily waves and three small earthquakes. For the first day A and F are 

 straight, but for the other two days there are daily waves. F shows a 



