ON SETS MO LOGICAL INVESTIGATIONS. 



41 



from 3 inches per day to 12 inches per hour, the object being 

 to record earthquakes. A few small shocks have been recorded, but 

 up to the present we have not succeeded in recording shocks of any 

 magnitude. Great difficulty is experienced in working underground 

 on account of the saline atmosphere, which causes corrosion. One 

 device tried for keeping the connection between the style on the boom 

 and the multiplying lever was a small pendulum where the bob was a 

 globule of shellac and the suspension was a quartz fibre. This was 

 found to work well and to be of great delicacy. 



Our very best thanks are due to the Earl of Dartmouth for granting 

 permission to work in the mine, and also to Councillors H. W. Hughes, 

 F.G.S., and Ivor Morgan for rendering valuable assistance in carrying 

 out these experiments. 



IX. List of Strong Shocks in the United States and Dependencies. 



By Professor H. F. Reid. 



The dates of the shocks between 1663 and 1737 are corrected so as 

 to give them according to the present method of reckoning, which 

 began in 1752. 



Abbreviations. 



B = Brighams' Catalogue, 'Memoirs of Boston Soc. of Nat. History,' vol. ii. ; 



' Note Additionelle,' by A. Lancaster. 

 H = Holden's Catalogue, ' Smithsonian Miscellaneous Collection,' 1887. 

 R=Rockwood's Lists in the ' American Journal of Science.' 

 P= Catalogues by Alexis Perrey. Also see Deckert's paper in the' Gesellschaft 



fiir Erdkunde,' Berlin, 1902. 

 S = Stewart's Catalogue (manuscript). 

 M = Martin's List (manuscript). 

 McA=McAdie's Catalogue, ' Smithsonian Miscellaneous Collection,' part of vol. xlix. 

 I=An intensity sufficient to damage walls and chimneys. 

 11= ,, „ to destroy a few buildings. 



111= ,, which has resulted in widespread disaster (see British Association 



Report, 1908, p. 78). 



Place 



1786 

 1790 (?) 



1806 March 24, 

 midnight 

 1811-1813 



New England 

 States 



Newbury, Mas- 

 sachusetts 



Newbury, Mas- 

 sachusetts 



New York 



Pavloff, Alaska 

 Inyo County, 

 Cal. 



Santa Barbara, 

 California 



New Madrid, 

 Missouri 



Intensity 



I 

 I 



II 

 I 



III 

 III 



1 

 III 



Remarks 



Three violent shocks. (B., p. 3.) 

 (B, p. 7.) 



Also felt at Boston. Strongest ap- 

 parently in Montreal. (B., p. 8.) 



Severe enough to throw down chim- 

 neys. Felt in Boston and other 

 places. (B., p. 9.) 



With volcanic eruption. (H.,p. 31.) 



Indians state that a shock similar to 

 that of March 26, 1872, occurred 

 about eighty years earlier. (IL, 

 p. 31.) 



Church walls cracked. (H., p. 32.) 



(References. — W. J. McGee, Bull. 

 G.S.A., 1892, iv., 411-414 ; G. C. 

 Broadhead, ' The New Madrid 

 Earthquake,' Am. Geol., 1902, 

 xxx., 76-87; W. J. McGee, 



