ELECTRICAL SIGNALLING AND THE SIPHON RECORDER. 367, 
more than thirty-five — as many as 120 words a minute have 
been recorded through a land line by this instrument, each 
word averaging five letters and each letter three distinct 
signals. Owing to an inductive effect between the electricity 
in the interior conductor of a submarine cable and the sea 
water round its exterior, there is a retardation of the velo- 
city of the electricity which is not experienced in land lines, 
and as a consequence the rate of transmission of signals through 
the latter is much- greater than through the former, so that 
the number of words recorded from a cable will depend more 
upon the speed capabilities of the cable for transmitting 
signals than upon the receiving qualities of the recorder. 
Twelve words a minute is the working speed of the Brest and 
St. Pierre Atlantic Cable, whereas the longest land lines will 
transmit signals as fast as it is possible to send them. The 
retardation due to induction is made very apparent by the 
motion of the coil of the recorder. When the electric 
signals are sent through a land line into the coil it oscillates 
quickly, and the waves traced by the siphon are sharp ; but 
when the signals are sent through a cable the motion of the 
coil is slower and more prolonged, the waves traced upon the 
paper being flat curves. 
When one stands alone by this beautiful instrument while 
it is at work, and observes the violet fire sparkling from the 
whirring u mouse-mill,” the sure obedience of the coil to 
Nature’s mysterious and inviolable laws, the apt inscription of 
the pen which. 
With pulses electric, 
Scatters its fine jet of ink, 
and is guided by Nature’s own fingers to the dictation of 
man many thousand miles away, he experiences one of those 
mental glimpses of admiration for human powers which he 
sometimes feels on viewing mighty enginery or triumphs of 
literature and art. 
However much in after years telegraphy may extend its 
domain and connect the centres of human life throughout the 
world, it is scarcely too much to say that the electrical instru- 
ments of the future will he no important innovation upon 
those of our own time, unless indeed some hitherto unknown 
phenomena provide new laws to be the basis for invention no 
less fertile. 
