DETERMINATION OF TRANSATLANTIC LONGITUDES 



477 



handled by the compute 



That this part of the work has been done laboriously and 



ly by Mr. Lucius Brown, the result itself is sufficient to demonstrate 



i 



Electrical Tests of Atlantic Cables as given by Clark and Sab 



Cable 



Date 



Length (in knots) 

 Diameter of Copper 



Diameter of Core 



Anglo-Atlantic. Anglo-AtlanUc. French-Atlantic. St. Plan* Duxtary . 



Resistance of Conductor, in Ohms, per knot 



Its specific Conductivity 2 (pure copper being 100) 



- 



Resistance of Dielectric in Megohms per knot 2 

 Electrostatic Capacity per knot in Microfarads 

 Resistance of Conductor per knot (when laid) in Ohms 8 

 Resistance of Dielectric per knot (when laid) in Megohms 



3 



1865 



1896 



.147 



.467 



4.27 



93.09 



349 



.3535 



4.01 



2945 



1866 



1852 



.147 



.467 



4.20 



94.63 



342 



.3535 



3.89 



2437 



1869 



2584 



.168 



.470 



• 8.16 



94.33 



235 



.429:. 



2.93 



520< 



1869 



71 



.087 



.28 



18.03 



92.63 



266 



740 



11.1 



2910 



faid 



assigned to the farad, as expre«ing 



ofarad 



What is called & farad, on page 442 of this memoir, is of the same value as the microfarad, introduced 



It 



differ flom those attached to the I- rench cable on pages 



Jopted the more 



jfi 



1 At 24° Centigrade. 



' Irrespective of Temperature and Pressure. 



VOL. IX 



66 





