78 TERRESTRIAL MAGNETISM. 



earthquakes on the Peruvian coast exert a local influence on 

 the phenomena of the earth's magnetic force ? 



18381842. Wilkes's Narrative of 'the United States 

 Exploring Expedition (Vol. i. p. xxi.) 



1838. Lieutenant Sulivan's observations in a voyage from 

 Palmouth to the Falkland Islands : Sabine, in the Phil. 

 Trans, for 1840, Pt. i. p. 129, 140, and 143. 



1838 and 1839. Establishment of the magnetic obser- 

 vatories in the two hemispheres at the cost of the British 

 Government, and under the able direction of Colonel Sabine. 

 The instruments were sent out in 1839; the observations 

 began at Toronto in Canada, at Hobarton in Yan 

 Diemen Island, and at St. Helena, in 1840, and at the 

 Cape of Good Hope in 1841. (Sir John Herschel in the 

 Quarterly Review, Yol. Ixvi. 1840, p. 297; Becquerel, 

 Traite d'Electricite et de Magnetisme, T. vi. p. 173). By 

 a laborious and profound investigation and treatment of the 

 rich treasure of observations obtained from these stations, 

 embracing all the elements or variations of the earth's 

 magnetic activity, Colonel Sabine, as Superintendent of the 

 Colonial Observatories, has discovered laws previously un- 

 known, and opened new views to science. The results of 

 his investigations have been published by him in a long 

 series of memoirs, entitled Contributions to Terrestrial 

 Magnetism, Nos. I. to IX. (and other detached memoirs) 

 in the Phil. Trans, as well as in separate volumes, and 

 constitute an essential part of the foundation of this branch 

 of cosmical knowledge. I will name only some of the most 

 remarkable among them. 1. Observations on days of 

 unusual magnetic disturbance, Yol. i. 1840 to 1844 inclu- 

 sive; and Phil. Trans, for 1851, Pt. i. p. 123139. 



