THE BLUE HILL OBSERVATORY. 



295 



The investigations nndertaken at the observatory may be divided 

 into three classes: (1) The routine work of making observations of the 

 local atmospheric conditions both by automatic registration and direct 

 observation; and the reduction and publication of results. (2) The 

 exploration of upper air by means of kites, and (3) Special studies of 

 important topics by the observatory staff and visiting scientists. 



The Blue Hill Observatory was established in 1885. Its report for 

 188G shows the institution still in its formation period. The annual 

 report for 1887, when it began to appear regularly in the 'Annals of 

 the Harvard College Observatory/ is almost complete, lacking only the 

 hourly values of the relative humidity of the atmosphere, but more 

 than making up for this by the very complete hourly record of cloud 

 observations (from 7 a. m. to 11 p. m.). In the report for 1888 all 



KITE METEOROGRAPH, 



BLUE HILL METEOROLOGICAL OBSER V 'TOR v, _ _ 



Record of a Kite Meteoeograph. 



the usual meteorological elements are given; but thereafter hourly 

 values of the precipitation and cloud observations alone are given, the 

 other elements being recorded only in summary. The reason for this 

 long backward step, for it certainly is such, was probably the desire to 

 economize the time required for reducing the observations and the cost 

 of printing, although it may have been thought that the publication of 

 the hourly observations in extenso during two or three years was suffi- 

 cient. This latter is not the case, however, for what we most lack in the 

 study of the air conditions in this country is reliable hourly observa- 

 tions conveniently accessible through print. It is especially desirable 

 to have these records when they are as carefully made as those at the 

 Blue Hill Observatory. It must be remarked, however, that the proper 

 reduction of automatic records is a very laborious task. 



