ELEMENTS OF GENERAL SCIENCE 



from carbon to zinc outside of it. The current which goes 

 through any part of this path goes through all parts. The 

 dry cells are said to be connected in series to form a dry- 

 cell battery. The cells in a flashlight battery are arranged in 

 this manner. This is a common 

 type of connection, which is used 

 in batteries for doorbell circuits, 

 gasoline engines, telephones, pro- 

 gram clocks, and automobiles. 



The tungsten lamps or the arc 

 lamps on the street are usually 

 connected so that the current 

 flows through each lamp in suc- 

 cession, and they are said to be 

 connected in series. Decorative 

 lamps for Christmas trees are also 

 connected in series. The chief 

 objection to this kind of circuit 

 is that if one lamp breaks, none 

 will give light. When the elec- 

 tricity passes from the generator 

 or battery and returns through 

 only one path, the path is called 

 a series circuit. 



216. Another kind of circuit. 

 The dry cells (fig. 98) might 



FIG. 99. Electric bells in an 

 apartment building 



The wires for the parallel circuit 



A ue \\nes lor me parallel ( lit un i i , i i 



are not shown. The lines indicate hay e been connected by joining 



what takes place when a given the Carbons of the Cells with a 

 push button is operated , , . ,, 



single wire and connecting the 



zincs in a similar manner. The electric current now flows 

 from all the carbons, or positive terminals, through the cir- 

 cuit back to all the zincs, or negative terminals, and the 

 cells are said to be connected in parallel or multiple. This 

 type, though not so common for cells as the series connection, 

 has extensive uses. A parallel circuit is peculiar in that there 



