v iii OBIGIN AND OPERATIONS 



constant temperature, as it rains very little during that time.' Bonnycastle, who compiled a 

 work on America, has nothing but what has been copied from the above authors ; but the 

 information most direct and recent has been obtained from a small volume entitled Repertono 

 Chileno, ano de 1835,' published at Santiago, a city nearly midway between the northern 

 and southern boundaries, and some sixty or more miles from the ocean. This was loaned to 

 me by the secretary of the Chilean legation near this government, and whose personal exp< 

 rience enables him to confirm its statements. It is most unfortunate, however, that the 

 meteorological journal ceases at a period of the year just half way between our interesting 

 epochs. I make a free translation for you from page 1 : ' Chile, from the brightness of 

 atmosphere, the benignity of its climate, and the fertility and productiveness of its soil, is 

 reputed to be one of the best and most delightful countries of the globe. Although the four 

 seasons are distinctly marked, the transition from heat to cold is scarcely sensible. Spring 

 begins on the 21st of September, summer in December, autumn in March, and winter on the 21st 

 of June. From the commencement of spring to the middle of autumn, from Copiapo to Talca, 

 the air is perfectly dry, it being very rare that any others than light rains fall in any year. 

 The rainy season sets in regularly about the end of April, and continues until the middle of 

 September. In the province of Coquimbo it only rains two or three times in the year, and 

 then but for a few hours ; in that of Aconcagua, Santiago, and Colchagua, two, three, or four 

 consecutive days of rain are followed by twelve, fifteen, or twenty of clear weather, and so on, 

 progressively increasing to the extremity of Chiloe, where rain falls all the year, and for entire 

 months at a time. Dew, which is deposited copiously throughout the state during spring, 

 summer, and autumn, measurably supplies the want of rain in the northern section.' 



" The meteorological journal alluded to as being in the volume was kept at Santiago by Don 

 F. C. Albo, whose records tell as follows: From February 15, 1835, to April 10, of the same 

 year, there were four observations daily, viz : at 4 and 10 A. M., and 4 and 12 P. M. During 

 these fifty-five days, there are 146 records 'clear,' 1 'very clear,' 3 'exceedingly fair,' and 

 2 ' fair;' in all 152, or thirty-eight entire days of fine weather, leaving but seventeen, or one 

 day in three, cloudy. From April 10 to May 12, both days included, there were only 100 

 records, or three per diem. These were made at times (specified) near 9 A. M., 3 and 11 p. M. 

 Of the 100 notations, 64, or very nearly two thirds, are 'fair,' and the larger portion of the 

 remainder are either ' cloudy' or ' partially cloudy.' There were only eight rains in the whole 

 thirty-eight days, and this, too, the middle of autumn in central Chile certainly a state of the 

 atmosphere not known to this part of the globe at the most favored season of the year. 



" Now, I pray you will not misunderstand my motives for the remarks and quotations respect- 

 ing the climate of Chile, but remember, there can be no personal preference for a station. My 

 desire is to contribute the utmost to the solution of the great problem, and to render the most 

 effective service which the locality selected, and the instruments committed to my charge, will 

 permit. If astronomers say, take the longest base and go to Chiloe, or even to a more southern 

 station, I will cheerfully acquiesce, and undertake the task with the same alacrity as though 

 the duties were to be rendered at Copiapo or Valparaiso ; but it is due to the object to be accom- 

 plished, as well as to myself, to submit these points, that I may not hereafter be charged with 

 the selection of a station unsuited to observations. Keflect on the subject and advise me what 

 shall be done. 



" Fortunately, the second question propounded may be more briefly despatched, viz : Will the 

 instruments named in my former letter permit the accomplishment of the object in the most 

 satisfactory or desirable manner ? I have already told you, that in writing that letter, my 

 expectations were limited to the results of micrometrical measurements. But as meridional 

 observations of the declination are free from the errors necessarily tending to vitiate those made 

 differentially near the horizon with even a permanently placed parallactic telescope, I am 

 satisfied that the objects of the enterprise can only be properly fulfilled by furnishing it with a 

 circle of not less than thirty inches diameter, whose divisions shall be read with micrometer 



