ELECTRICAL RESISTANCE UNDER PRESSURE. 



129 



of relative values, and accordingly in smoothing the results and 

 making the interpolations and extrapolations involved in making a 

 table of resistance at uniform intervals of pressure and temperature, 

 the logarithm of the resistance was plotted against pressure instead 

 of resistance itself. 



Except for two bad points, the maximum departure of any point 

 from a smooth curve at any temperature was 2% of the resistance 

 at that point, and the agreement was usuall}* much closer. 



4 5 6 7 8 



Pressure. Kg. / Cm.' X 10' 



Black Phosphorus 



12 



Figure 11. Relative resistances of black phosphorus at several constant 

 temperatures as a function of pressure. 



The smoothed results are shown in Table XVII, which gives resist- 

 ance at 0°, 50°, and 100° at even 1000 kg. intervals, and in Figure 11. 

 The use of significant figures in the table should be mentioned, the 

 number of decimal places not being constant throughout the table. 

 The accuracy of the results justifies only the places shown. The 



