INTRODUCTION. x i x 



tions made at the Bolsa (Exchange), for the two years preceding our 

 arrival. The observations of Mr. Heath have been reduced to our 

 standard for temperature, &c. I was gratified to find that by a compa- 

 rison made with that of Mr. Pentland the year previous, Mr. Heath's 

 instrument showed the same deviation as with ours, when reduced 

 to the Royal Society's standard. I have given the results of Mr. 

 Heath's observations on Plate VI., page 138, where the tri-monthly 

 means are shown, and also the days of the month on which the 

 maximum and minimum occurred ; it will be seen that the extreme 

 annual range of the thermometer is from 50 to 86, a difference of 

 36; that the mercurial column has a higher range during the 

 winter and spring months than it has in the summer and autumn, 

 which seasons correspond with the north and south monsoon. It is 

 to be understood that these observations do not include the night hours, 

 and but eight hours of the twenty-four, viz., from 8 A. M. till 4 p. M., 

 at which times and at noon the observations were made. It certainly 

 would have been desirable to obtain a series including the night 

 hours also ; but these day observations nearly correspond to the 

 maximum and minimum hours, and, although imperfect, they may be 

 regarded as throwing some light upon the movements of the mercurial 

 columns at Valparaiso, until more perfect ones are made. According 

 to them, the mean annual temperature is 66 '1 Fahr., and the mean 

 standing of the barometer 29 - 987 in.; greatest oscillation '570. 



Chili occupies but a narrow strip of the western side of the vast con- 

 tinent of South America, extending through twenty degrees of latitude. 

 It has the lofty range of the Andes as its eastern boundary, and nu- 

 merous spurs of great elevation intersecting the country in many parts, 

 which, with the cold waters flowing along its shores, must materially 

 affect the climate in particular localities. The climate of Valparaiso 

 cannot be taken as any criterion by which to judge as to that of the 

 country ; indeed it may be remarked that what may be descriptive 

 of one section will not by any means accord with that of another ; 

 from its extreme southern to its northern point the climate differs very 

 materially. Throughout the whole length of the coast, a distance of 

 over one thousand miles, and this trending north and south, the 

 thermometer varies only a few degrees : the great and remarkable 

 variation is in the degree of moisture, for while the extreme south 

 has constant rains, the extreme north is totally destitute of moisture, 

 the country incapable of cultivation and quite a desert ; between the 

 two we have a constant gradation. The cause seems to be obvious : 



