4 i4 SECTION MECHANICS. 



because their whole attention is devoted to their paper and nothing 

 else. The defect of that instrument is probably its complication, and 

 it requires skilled clerks to work it. 



The form of Sounder that has been introduced in America is this 

 little instrument, which we call the " Pony Sounder." This is sim- 

 plicity itself. It simply consists of a coil, through which the currents 

 flow and an armature which is attracted. There is nothing here to 

 get out of order, and the rate of rapidity with which the instrument 

 is read is something wonderful at times. The rate at which these 

 instruments are worked depends upon the skill of the clerk in 

 manipulating his key. Here is the key that is commonly used. The 

 clerk simply depresses that key, and the rate at which he depresses 

 that key is practically the rate at which the instrument records and 

 the rate at which the clerk receives. But human nature will tire. A 

 clerk who commences to send in the morning at the rate of forty words 

 a minute, in an hour or two descends to thirty-five words a minute, 

 and then gets to thirty words a minute, and in the course of the day 

 his rate is still further lowered. It therefore speedily struck our 

 electricians that an advantage would be obtained if we could replace 

 the skilled labour of the clerk by some automatic apparatus which 

 would send his currents for him indeed, the very earliest form of 

 telegraphy suggested by Morse in America was an automatic sender. 

 His letters, his numbers, were formed by pieces of type, and these 

 were simply placed in a stick and passed through a machine which 

 sent the currents which made the record at the distant stations. 



In the year 1846, Bains conceived the idea of punching these 

 dots and dashes in broad paper, and by passing this strip underneath a 

 spring he thought that he could send to the distant station the signals 

 and have them properly recorded in fact, the experiment was perfectly 

 successful, and the speed with which messages were sent was some- 

 thing astonishing. In an office of short circuit we were able to attain 

 a speed of about 400 words a minute, and when I mention that the 

 fastest speed previously attained was from thirty to forty words a 

 minute, you will easily understand that the advantage was very con- 

 siderable. But the conditions of our lines in those days, the character 

 of the instruments themselves was such, that while we were able to get 

 this high speed on short circuits in our own rooms, the instrument 



