INTRODUCTION. xv ij 



A similarity of movement in the barometer and thermometer is satis- 

 factorily exhibited on the diagram of our observations at this place. 



Rain fell during thirty consecutive days to the amount of 8 - 26 in. ; 

 this was the season in which there is least. The greatest fall in 

 twenty-four hours was 1 - 08 inches. 



The opinion has been and is still entertained, that the temperature 

 of the southern hemisphere is much lower than that of the northern ; 

 if this opinion is founded on the standing of the thermometer, I have 

 little doubt that it will prove erroneous, and that the mean annual 

 temperature will be found higher in the southern than the northern 

 hemisphere, while the difference between the maximum and minimum 

 is probably much less. That the cold of winter cannot be so great is 

 evident from the habits of the natives of Tierra del Fuego, who use 

 little or no covering throughout the year. I may also adduce the 

 standing of a self-registering thermometer, that was left by Lieute- 

 nant Kendall, of H. M. S. Chanticleer, at Deception Island in 1829, 

 which when examined thirteen years afterwards was found to have 

 fallen only to 5 Fahr., a much less degree of cold than it would 

 have shown on the parallel of 63 north latitude. 



OBANGE HABBOTJB TO VALPARAISO This passage was made in 



the months of April and May : it was a boisterous one, and occupied 

 twenty-three days. The extreme latitude we reached was 58 S. ; 

 the lowest temperature of the air was 37; the water 4 Avarmer. 

 The .mercurial column continued to descend until we reached our 

 most southern point, then it as gradually rose without much varia- 

 tion, until we had attained the latitude of 43 south, and passed 

 through the stormy latitudes, which are comprised between the forty- 

 third and fifty-second parallels of latitude. Our distance from the 

 coast was about two hundred miles, and our course parallel to it. 

 The winds we encountered were violent from the northwest to south- 

 west, which are the prevailing winds on the west coast of South Ame- 

 rica, before spoken of as being accompanied with much rain : we had 

 but little rain, though the mean degree of moisture was '881. The 

 parallels of latitude in which these violent winds from the southwest 

 and northwest constantly blow are well known, but their extent in 

 longitude is as yet undetermined; yet there is very little doubt that 

 they have their limits, and it is believed that they extend only a short 

 distance to the west in the great basin of the Pacific, as they are not 

 experienced to the westward of 90 west longitude, about five hundred 

 miles from the coast. How much their direction, velocity, and bois- 



5 



