BAKEWELL'S PROCESS 3 



most successful modern methods of transmission. 

 Bakewell's machine, which created some attention 

 as far back as 1847, consisted of two synchronously 

 revolving metal cylinders one at each end of the 

 telegraph lines, over each of which a metal style 

 traced a spiral path (in the manner of the modern 

 phonograph). Upon one cylinder was placed a 

 sheet of tinfoil with the sketch drawn in ink made 

 with shellac, and on the receiving drum was placed 

 a sheet of paper prepared chemically, so that on 



Battery 



FIG. i. 



passing an electric current through it a chemical 

 mark or stain was made. It appeared as seen in 

 Fig. i in its simplest form. A and B represent 

 the two cylinders, tracing over which are shown 

 two styles. A battery is in the circuit. It will 

 be readily seen that when a line in the sketch 

 which consists of shellac, comes under the style of 

 A, the current flowing through the circuit will be 

 broken, whereas when the bare tinfoil lies between 

 style and cylinder the current will flow. 



This current therefore flows intermittently 

 through the chemically -prepared paper attached to 

 the drum /?, and when it flows, it causes a chemical 



