﻿40 



E>oxes filled 

 with 

 eavy materials 



The instrument was so placed that the boom pointed S. — N. true, thus in an opposite direction to its 

 former position. The period of the boom was made exactly 15 seconds. 



From January 29 until March 18, 1903, the seismograph was dismounted, the brick pillar being then 

 employed for pendulum work, and was finally dismounted in December, 1903. 



L. C. Bernacchi. 



Amongst the various records brought home l)y the .ss. " Discovery " from the Antarctic Regions, a long 

 series refer to the movements of a horizontal pendulum. This instrument, which is similar to a type 

 adopted by the British Association and established at 38 widely separated stations in various parts of the 

 world, was in charge of Mr. Louis Bernacchi. 



When we read Mr. Bernacchi's log we recognise the exceptional difficulties, meteorological and 

 otherwise, under which he worked. This and the fact that a hurried departure only admitted of a few 

 hours' instruction in the practical working of the instrument he had to use, entitle him to the sincerest 

 congratulations on the results he has brought home. 



The huts, to which Mr. Bernacchi refers, were 30 to 50 feet above sea-level at a place in longitude 

 166° 44' 45" E. and latitude 77° 50' 50" S., about 15 miles distant from Mounts Erebus and Terror. The 

 former of these volcanoes was always active. 



The records obtained refer to Changes in the Vertical, Tremors, Pulsations, and Earthquakes. In many 

 instances these records, when taken by themselves, have little value, but when analysed in conjunction 

 with registers obtained by similar and similarly installed apparatus at very distant stations they throw 

 light upon hitherto unsuspected phenomena which take place within and on the surface of our world. 



In the following pages I give a register of the earthcpiakes recorded by the " Discovery." To this is 

 appended a list of very large earthquakes which were not recorded by the " Discovery " seismograph, 

 although at the time of their occurrence this instrument appears to have been in working order. Finally, 

 I give a certain number of conclusions arrived at from an analysis of these various observations. The 

 greater number of these are to be found in a paper on " Preliminary Notes on Observations made 

 with a Horizontal Pendulum in the Antarctic Regions," see ' Proceedings of Royal Society,' Series A, 

 vol. 76, May 29, 1905. 



J. Milne. 



