Arizona republican., 1920-12-26
"knoIU the Heart or Your Car,' 9 Says
 Ignition Expert
By A. S. Earnhayt, Auto Electrical En-
 Cineer

Ny As o. GarnnaFt, Auto Electrical En-
 gineer
 There is hardly motorist who does not concede that he is negligent of ths heart of his oar--the electric system
 The modern automobile stands moro abuse than any other type of machine or motive plant Take. for example. the locomotive engine. It is handled exclusively by men long trained for that purpose yet, notwithstanding this fact. 1t is thoroughly examined and in- spected after each and every division run.
 The automobile is handled hy owners who. on an average cannot explain one fundamental principle of it's construc ton, yet in the face of this, engine fati- ures are few in proportion Co the care used.
 Mir. Car Owner. you may have The finest motor that engineering skin can produce. but unless tho electric spark GOT heart heaD is kept properly ap- piled. your motor is a failure. The proper circulation of electric current is just as necessary Go the automobile en- zine as tho blood circulation in the hu- man body.
 Tho ignition system on any car con sists of two distinct circuits commonly known as the primary or first circuit and the secondary, or second curcuit. There must be a source from which we derive any given substance. In this ease, if the primary current is obtained from the battery the source is chemi- cal action. If it comes from n magneto. it's source is mechanical action.
 Now, I shall treat only of battery ignition. as magneto ignition is iden- tical. other than the source of power Somewhere in your car fastened in some obscure corner is the battery. from which we derive the primary cur rent. Now, then. follow this current. On each end of your battery there is a terminal. One is marked positive and tlie other negative, meaning. in plain English, the giving terminal and the receiving terminal. respectively.
 From one of these terminals we take a wire to your switch on the dashboard thence Co the coil and from the coil to one side of the breaker, through the breaker points usually to the frame of the motor. thence back to the receiving terminal. thus completing the primary circuit
 If you will closely observe the above, you will readily see that when you close your switch and your breaker points come together and there is a complete electric circuit from one end 
 back into tho other end of the battery. In this circuit Hes 70 per cent of your electrical trouble as this current is of lew voltage and must be positive In it's action. It is, therefore, subject to fail- ure from the following causes: Poor battery action, bad connections at switch, battery or coll, and poor ad- justment on the breaker points.
 The primary circuit is the direct source of the secondary current. When you complete your primary circuit by closing tho switch and breaker points, the current flows around this circuit. Now. within your coil, there is a sec ond winding which Is so arranged that when the breaker points part abruptly breaking the primary circuit, it backs up, creating an induction which sets up current fin the secondary winding This current is high voltage and trav- els with lightning speed from coil to distributor head thence through the motor out onto the spark plug wire to plug. across the gap to tho frame of the motor and returns latent current to it's mother source.
 Thus when we take into considera- ton the fact that these two complete actions must take place from 1000 tc 4O00 times per minute. depending or the speed of the motor, you can readily appreciate the absolute necessity of the proper care for the 'heart' of your car The majority of the motor fall ures are due to a lack of, or improper knowledge of the above facts.