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POPULAR SCIENCE MONTHLY. 



recording meteorological instruments used in this manner. Mr. Eddy, 

 of New Jersey, used his kites in making this first trial. The work has 

 been pushed with such success that records of atmospheric pressure, 

 temperature, relative luimidity and wind velocity have been secured by 

 means of kites up to a height of 15,800 feet above the sea. 



In a pioneer work of this kind, it was found necessary not only to 

 modify old apparatus and methods so as to fit the novel applications, 

 but also to devise new ones as well; and many of the details of the sys- 

 tem as established at Blue Hill have been copied by meteorologists in 

 the prosecution of similar researches both in this country and in 

 Europe. 



In this connection the Blue Hill studies of the clouds have led to 

 the consideration of many problems to which these phenomena either 

 directly or indirectly furnish a key. As in other studies carried on 

 there, this work has been undertaken in the light of what has been done 

 by other investigators; and in Mr. Clayton's report on the subject an 

 excellent summary of what has already been accomplished introduces 

 us to the more distinctively Blue Hill work. It has too frequently hap- 



EVOLUTION OF THE KlTi-: REEL. 



pened that the cloud work which has been done in different parts of 

 the world has had its value much decreased owing to uncertainties in 

 cloud nomenclature, and much of the recognized value of the Blue 

 Hill work is to be attributed to the great care exercised in this prelimi- 

 nary matter. A valuable contribution has been made to the revision 

 of cloud nomenclature, taking into account the elevations of the clouds. 

 The annual and diurnal periodicity of clouds has been carefully studied 

 on the basis of cloudiness at different levels. 



