﻿650 
  

  

  Messrs. 
  E. 
  Bellini 
  and 
  A. 
  Tosi 
  on 
  a 
  

  

  In 
  the 
  first 
  of 
  these 
  arrangements 
  (fig. 
  7) 
  the 
  excitations 
  

   of 
  the 
  two 
  systems 
  are 
  in 
  phase 
  ; 
  in 
  the 
  other 
  three 
  cases 
  

   they 
  are 
  in 
  quadrature. 
  The 
  diagrams 
  of 
  the 
  energy 
  radiated 
  

   in 
  the 
  different 
  directions 
  (figs. 
  11 
  and 
  12) 
  are 
  selected 
  from 
  

  

  Fig. 
  11. 
  

  

  among 
  the 
  large 
  number 
  which 
  have 
  been 
  determined. 
  They 
  

   were 
  obtained 
  with 
  the 
  ther 
  mo-galvanometer 
  in 
  a 
  similar 
  

   manner 
  to 
  that 
  employed 
  in 
  the 
  case 
  of 
  the 
  bilateral 
  directive 
  

   system. 
  In 
  particular 
  the 
  diagram 
  of 
  fig. 
  11 
  was 
  obtained 
  

   when 
  using 
  the 
  arrangement 
  shown 
  in 
  fig. 
  7 
  ; 
  and 
  that 
  of 
  

   fig. 
  12 
  with 
  the 
  arrangement 
  of 
  fig. 
  10. 
  In 
  the 
  last 
  diagram 
  

   (fig. 
  12) 
  the 
  phase-difference 
  between 
  the 
  radiation 
  from 
  the 
  

   two 
  component 
  systems 
  turns 
  out 
  to 
  be 
  much 
  smaller 
  than 
  in 
  

   the 
  preceding 
  diagram, 
  and 
  only 
  by 
  means 
  of 
  this 
  last 
  

   arrangement 
  (fig. 
  10) 
  have 
  the 
  very 
  small 
  values 
  of 
  the 
  

  

  