Hydrography^ and the Art of Navigation* 65 



1822, after the earthquake which overturned the towns of Val- 

 paraiso, Quillota, &c., in ChiH, great part of the country was 

 found to be elevated from one to two metres above its former 

 level. The earthquakes of 1834 appear to have been still more 

 severe than that of 1822. It will therefore be of importance to 

 examine whether they have not in like manner produced a sud- 

 den rise of the 'country. A beach on which the sea, by the ef- 

 fect of the tides, never ascends beyond one or two metres 

 ought to furnish a multitude of appearances, such as " embarca- 

 deres,"" banks of oysters, muscles, and other shell-fish adhering to 

 rocks, by means of which any doubt on the subject may be re- 

 moved. A glance at the localities will do more in this respect, 

 than the necessarily vague indications which we can furnish here. 

 We can conceive, however, that we ought to mention the lake 

 of Quintero, which communicates with the sea, as well fitted to 

 afford indisputable proofs of changes of level. Recourse should 

 likewise be had to the hydrographical charts of Vancouver, Ma- 

 laspina, &c., for it is by no means probable that these risings 

 would take place on the shore, without the bed of the sea parti- 

 cipating in them. 



Sudden or gradual elevations of the ground appear destin- 

 ed to perform such an important part in the history of the 

 earth, that we must particularly invite the officers of the Bonite 

 to take note of all recent phenomena of this nature that they 

 meet with, and in an especial manner to direct their attention to 

 the coast of Peru. * 



Earthquakes, — According to an opinion pretty generally en- 

 tertained in America, earthquakes are more frequent in certain 

 seasons than in others. If this were fully ascertained to be the 

 fact, it would be of extreme importance in the physics of the 

 earth. A complete collection of the journals which have been 

 published in Chili for twenty years, examined in relation to this 

 • At the moment when this sheet is going to press, I learn that some Botes 

 of Captain Fitzroy have just been read before a court-martial met at Porta- 

 mouth, for the trial of Captain Seymour, of the English frigate Challenger^ 

 shipwrecked on the coast of Chili. These notes, designed to account for the 

 catastrophe, take notice of the changes which the currents have undergone 

 near the port of Conception, since the earthquake of February 1836. Cap- 

 tain Fitzroy likewise states, that the island of SanU Maria has risen 10 Eu- 

 glish feet. 



VOL. XXI. NO. XH.— JULY 1836. E 



