434 



WELLS'S NATURAL PHILOSOPHY. 



passes along the wires, and through the coils* surrounding the pieces of soft 

 iron, F and E, thereby converting them into magnets. Above these pieces 

 of soft iron is a metallic bar, or lever, A, supported in its center, and having 

 at one end the arm, D, and at the other a smaU steel point, o. A ribbon of 

 paper, p h, rolled on the cylinder, B, is drawn slowly and steadily off by a 

 train of clock-work, K, moved by the action of the weight, P, on the cord, C. 

 This clock-work gives motion to two metal rollers, G and H, between which 

 the ribbon of paper passes, and which, turning in opposite directions, draw 

 the paper from the cylinder B. The roller H has a groove around its circum- 

 ference (not represented in the engraving), above which the paper passes. 

 The steel point o of the lever A is also directly opposite this groove. The 

 spring, r, prevents the point from resting upon the paper when the telegraph 

 is not in operation. 



Fig. 361. 



The manner in which intelligence is commimicated by these arrangements 

 Is as follows : The pieces of soft iron, F and E, being rendered magnetic by 

 the passage of a current of electricity transmitted from the battery through the 

 coils of wire sun-ounding them, attract the metal arm D of the lever A. The 

 end of the lover at D being depressed, the steel point o at the other extremity 

 is elevated and caused to press against the paper ribbon and indent it. "When 

 the current from the batterj' is broken or interrupted, the pieces of soft iron 

 F and E being no longer magnetic, cease to attract the arm D. The lever 

 A is therefore drawn back to its former position by the action of the spring r, 

 and the steel point o ceases to indent the paper. By letting the current flow 



• These coils consist of very fine copper wire, some thousands of feet being pener- 

 ally contained in them. In this way a magnet of small size and great power may be 

 .obtained. 



