178 



INDEX 



Potential-gradient apparatus, eye read- 

 ing, no. 2 



procedure for observations, 

 4-5 

 recorders, nos. 4946 and 4947 

 description, 4-7 

 figs. 12, 17, 25, 26 

 location, 4, 5 

 meteorological observations, 



7 

 observer's reports, 31, 33, 

 34, 35, 38, 43, 44 

 comments, 34, 35, 37, 39, 

 42 

 procedure for observations, 7 

 discussion of data 



diurnal variation, 135-136 



fig. 1, 163 

 harmonic analysis, 135 

 table 2, 136 



Potential-gradient, discussion of data, 

 selected days, 135 



table 1, 136 

 universal time component, 135- 

 136 

 reduction factors 

 method, 5, 41 



results, 34, 35, 36, 41, 129-134 

 stations, 5, 32, 33, 34, 36, 41 

 fig. 15, 26 

 tables of data 



daUy observations, 66-101 



explanatory note, 65 

 diurnal-variation observations, 

 105-112, 114-121 

 explanatory notes, 103, 113 

 engine, 



effect, 7, 135 

 operation, 65, 88, 90, 100, 

 IIJ, 115-121, 135, 136 



Potential-gradient, tables of data, 

 sail, 



effect, 5, 7, 129-134, 135 

 positions, 7, 66-101, 113, 

 115-121 

 variations, sources, 1 



Resistivity, columnar of the atmosphere, 

 lower region, 148-150 



computation of height, 148-151 

 total, 145, 147, 149-151 

 upper region, 148, 149 

 Radioactive content 

 apparatus 4 (RCA4) 

 description, 15-16 

 fig. 5, 22 

 location, 3 



observer's reports, 31, 33, 37 

 38-39, 44, 45 

 comments, 34, 37, 40 

 measurements, 16-17 



