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Mr. Sidney George Brown 



[March 12, 



electrical illustration of that fable of " the tortoise and the hare " or 

 the principle of " more haste, less speed." 



As the slower signals get through the cable with more vigour 

 than is necessary, the ingenuity of experimenters is to retard them 

 and to assist as much as possible the quicker ones, so that all the 

 signals, whatever their period, shall arrive with exactly the same 

 strength. 



Cromwell Yarley in 1862 patented a system for the reduction of 

 distortion on cables by inserting condensers of suitable capacity 

 in series with the conductor at each end of the cable. 



The reason for the abohtion of distortion is obvious : the 

 condenser absorbs the signals of slow frequency, while the cable 

 transmits them. 



The condenser allows the signals of high frequency to pass 

 through it, although the caljle has attenuated them. It is therefore 

 possible to so arrange the condensers at each end of the hue that 

 the condensers and the cable together will more or less correct one 

 another, and the distortion be reduced. 



Unfortunately, the absorption of a series condenser is relative, 

 and is inversely proportional to the frequency ; it absorbs more of 



Table I. 



Except in Case I. (near its end) the lag in every case is proportional to x. 



Frequency, 6-36 per second. 



Submarine telegraph cable — r = 1-684 ohms per naut, fe = 0-42 mfd. per 

 naut. The current received by recorder would be 82 times this if we had no 

 capacity. 



At X nauts from sending end these are the volts and amperes : — 



I. There is a recorder with 317 ohms resistance at the end of 1825 naut 

 cable. 



II. Infinite cable. 



III. Infinite cable, . 4 henrys per naut ; no leakance. Not much distortion. 



IV. Infinite cable, 0-4 henrys per naut ; leakance, 1-768 x 10-6 ohms per 

 naut to give no distortion. 



(See Figs. 3 and 4.) 



