LAYING CARRIED OUT ACCORDING TO THE THEORY. 165 



my theory. It was however difficult to do this on 

 the spur of the moment. The brake, which we found 

 on arriving at Bona on the cable -ship that already 

 awaited us, proved much too weak for balancing the 

 weight of the cable at great depths. Moreover the 

 steam-power of the ship was too small to overcome 

 the great force with which the cable would endeavour 

 to slide down the inclined plane. Finally there was 

 no contrivance for measuring this force, and for deter- 

 mining accordingly the amount of the brake action 

 required. I first had a simple dynamometer constructed 

 by the carpenter, which rendered it possible to ascertain 

 the extent of the actual strain on the cable while it is 

 paid out by the amount of flexion of .a length of the 

 cable stretched over two rollers, between which a third 

 weighted roller rides on the cable. Furthermore I had 

 the brake -wheel strengthened as far as possible, and 

 furnished with strong water- boxes. Lastly I caused 

 the captain of the war- ship to pass a tow-rope from 

 his vessel to the bows of the cable -ship, in order to 

 obtain the requisite force for overcoming the back- 

 ward drag exerted by the cable. 



Thus barely provided, we began in the evening 

 the laying of the cable from Bona. As long as the 

 water was shallow all went well, and my precautions 

 were soon deemed superfluous. After a few hours, when 

 we got into much deeper water, it appeared however 

 that the attainable brake force was not sufficient. We 

 paid out too much cable and, when morning dawned, 

 had already used more than a third of the cable. 



