A Graphical Synthesis of the Linear Vector Function. 545 



not quite identical, the H.F. Carve II. showing a much 

 more pronounced " kink/' It is unfortunate that the rime 

 at our disposal was insufficient to enable this problem to be 

 subjected to a more careful examination. It is doubtful 

 whether this discrepancy is due to an inherent defect in the 

 methods of observation or whether there is actually here a 

 difference between the H.F. and D.C. resistances. We hope 

 to pursue the inquiry at another time. 



Summary. 



Methods' of utilising H.F. oscillation valve-circuits for the 

 the measurement of resistance have been devised, the principles 

 involved being extensions of the senior author's " ultra- 

 micrometer " circuits. These methods are capable of great 

 precision and are suitable both for metallic and electrolytic 

 resistances. 



Preliminary tests indicate that ordinary electrolytes offer 

 the same resistance to high * as well as to low frequency 

 currents. 



Observations on glvcerine solutions, which show anomalous 

 " resistance-concentration " variations for D.C, are somewhat 

 inconclusive, but seem to show this to be more pronounced 

 under H.F. conditions. 



It is hoped to continue the work, especially at still higher 

 frequencies and in connexion with the anomalous effects in 

 glycerine solutions. 



University College, Dublin. 

 Aug. 25, 1921. 



LXIII. A Graphical Synthesis of the Linear Vector 

 Function. By Prof. Frederick Slate f. 



PREVAILING use of the polygon-graph employs the 

 same scale for the resultant, and throughout any 

 group of its components. But the resultant can be ex- 

 pressed more comprehensively and still simply, when an 

 individual scale-factor is allotted to each constituent vector. 

 This idea is found to open an approach to linear vector 



* The frequency used was about three-quarters of a milliou. Even at 

 this frequency the "'skin effect " is negligible in such poor conductors. 

 t Communicated by the Author. 



Phil. May. S. 6. Vol. 43. No. 255. March 1922. 2 N 



