662 ALEXANDER MACFARLANE ON THE 
TaBLE X1X.—Pressure Curve, 27th June 1877. Dielectric, Air. Electrodes 
large discs. Length of spark, ‘5 centimetre. 
Equation, V = 046342 ,/ {p?+199-01p'. 

Pressure in Opeaceen Mean Diff. of | Calculated 
mm. of Deflection. Zero. Diff. of a pt f acacia in Pp bee oy Difference. 
Mercury. N. We Potential. ae SEITE pew Vi_-V. 
1 Potential. measure. abs. meas. 
Dp. nm—n. VL 




s| 42 514 35 |) 
66 479 : 35 35 6-13 6-13 0-00 
l} 479 “ 35 «| f 
447 513 66 
169 | 447 4 66 \ 66 11-56 11°56 0-00 
447 ‘ 66 
415 508 93 |) 
273 | 418 \ 90x 90 15°75 13-91 41:84 
414 510 6 lt 
392 BOS. | 116 
376 ' 389 : 119 x \ 119 20°83 21-55 ~0°72 
393 510 | tay 
358 ‘ 152x 
479 | 360 Bee | 165 \ 152 26°60 26-41 +019 
356 5 159 
351 bse | 16% . 
582 | 343 520 | 17x \ 177 30:98 31-24 — 0-26 
350 523 | 173 
295 Blu | “Otd x 
740 | 310 517 | 207 \ 215 37°63 3863 1-00 
318 525 | 207 



Taste XX.—Pressure Curves, 29th June 1877. First Curve. Single | 
Discharge. Dielectric, Air. Electrodes, large discs. Length of spark, — 
‘5 centimetre. 
Equation, V = 046853 ,/ { p’ + 207-06p'. 




LoS : Difference Mean uae aes : i 
, Deflection. Zero. of 3 ae Difference. ys 
tees - a, Potential. ee a ees tp WE=V. . 
i ge Ve 
478 495 17 : oe 
20 i 475 . 20x \ 20 S43 3:16 —003 ) | 
A477 e 18 
490 530 40 ed 
60 | 490 529 39 Xx \ 39 6-11 5:93 +018 | 
490 fi 39 X i 





