DURYEA LABORATORIES CHAS. E. DURYEA,consul™genor 



J>ear Vr \'it*an aw^u^mS" 24 1, * ov 122 ° 



On the train I had some time to puzzle over that car. Been working 

 nights to make up time lost in the day eo did not hav much. 

 5 I made a sketch for you but did not show trespring that holds 



5 the circuit breaker in contact with the spark point. That thin finger 



was it. A spring was wound spirally — no< helically — around the 

 i projecting end of the breaker pivot and the end of the spring hookt 



over the thir. finger. See sketch herwith. 



Just how the central end of the spring wire was fastened to the 

 5 square of the pivot I do not kno. We did in some cases bore a hole 



| thru and simply stick the spring thru but this put most of the action 



E 



a right at the bend in the wire and it broke v-iickly. s ° ln other cases 



I we fitted a light grooved apod or pulley and wound the spring around 



this and so avoided a sharp bend. If this was used it has been lost with 

 the spring. A couple generations of boys playing in tha* barn "as too 



; many. 



he Haynes steering ketch also worries me. If that vertical 

 post came up thru that slot in the floor the crank had to be long 

 as the sketch shows in order to get over to the driver conveniently. 

 Then if he tried to make a complete circle with it he could not reach 

 far enuf forward to do it easily. And he had to make a turn or twc be 

 cause H shows bevel gears of about same size so the post had to make 

 same number of turns the worm made. Sketch herwith to il lustrate my 



S thought. 



" re for the historical facts 



Figure 17. — Letter explaining the circuit breaker spring and the brass 

 projection on top of the ignition chamber. Mr. Mitman was, at the time, 

 curator of engineering in the U.S. National Museum. 



14 BULLETIN 240: CONTRIBUTIONS FROM THE MUSEUM OF HISTORY AND TECHNOLOGY 



