20 



BLAIR— EXPLORATION OF THE UPPER AIR [March s. 



in making a flight. They carried a hne 12,100 meters long. In our 

 highest flight above referred to 11,735 meters of line was put out on 

 nine kites. 



Fig. 5. Method of bridling kite. 



The line is of piano wire made up about as follows 



Meters. 

 500 

 500 



2,000 



3,000 

 5,000 

 5,000 



Inch in Diameter. 

 ,026 

 .028 

 .032 

 .036 

 .040 

 .044 



In all about ten miles of wire. 



The reel is a very important part of the kite-flying apparatus. 

 Its design should be such that the operator can easily control the rate 

 at which wire goes out or comes in from o up to 4.5 meters per 

 second. This enables him to keep his kites flying even if they are 

 becalmed during flight, to throw them up through the calm strata 

 of air which are often encountered, especially in the summer months, 

 and, with the aid of a skilled field man, to start and land kites with 

 little or no breakage. Our reel at Mt. Weather is equipped with a 

 variable speed motor so geared to the drum that the wire may be 

 brought in at any rate up to 2.7 meters per second. 



