LAYING DEEP-SEA CABLES. 445 



times the cable's weight in water per mile. Hence, 

 the cable will bear its own weight in eleven miles 

 depth of water, or 4*64 times the 



Deepest Water to be encountered, 2,400 fathoms, 

 or less than 2\ nautical miles. 



Length of Cable Shipped, 2,300 nautical miles. 



APPENDIX II. 



Let W be the weight of the cable per unit of its 

 length in water ; T the force with which the cable 

 is held back at the point where it reaches the 

 water (which may be practically regarded as equal 

 to the force with which its egress from the ship is 

 resisted by the paying-out machinery, the differ- 

 ence amounting only to the weight in air of a piece 

 of cable equal in length to the height of the stern 

 pulley above the water) ; P and Q the transverse 

 and longitudinal components of the force of 

 frictional resistance experienced by the cable in 

 passing through the water from surface to bottom ; 

 i the inclination of its line to the horizon ; D the 

 depth of the water. 



The whole length of cable from surface to 



bottom will be - ; and the transverse and 

 sin i 



longitudinal components of the weight of this 



portion are therefore - - cos 2, and WD respec- 

 sin t 



