[D8752AAQ], Letter from Chicago and Northwestern Railway, C P Carr to Thomas Alva Edison, December 25th, 1887


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[D8752AAQ], Letter from Chicago and Northwestern Railway, C P Carr to Thomas Alva Edison, December 25th, 1887

Editor's Notes

"You are of course aware of the defect in the arrangement of the Western Union Standard Quadruplex viz. the effect of the reversals at the distant end on the home neutral relay. You are also aware that this defect is at present partly over come by the Smith relay and the arrangement of his third coil and non-adjustable condensers in a bridge. This does not perfect the working of the common side by any means and the repeating sounder is still necessary to over come the defect. I wish to call your attention to the fact that I have over come the difficulty entirely with a simple contrivance which not only enables the perfect working of the common side but also the saving of one condenser together with repeating sounder and battery on each set (about $15.00) at no additional cost. I feel certain the Western Union Co. will see the benefit and be anxious to take it up. From what I have learned this is a matter which has not been before accomplished for any practicable use and I write you in hopes that should you see any thing in it you might be willing to take hold of it & bring it out to fair advantage for me. Mr. Thayer Supt. Telgh. And myself have given the matter a thorough trial and he will lay the idea before Col. Clowry and Mr. Summers of the W.U. Co. this week and see what that Company would consider such an improvement and saving to be worth. I think you will readily see that if there is a saving of $15.00 per Quad. Set together with an improvement the W.U. Co. would not be slow to adopt it. I of course am anxious to do the best I can with my idea provided there is to be any thing in it and I write you for your advice and to see what you would be willing to do about it. I hope you will let me hear from you without delay."




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Thomas A. Edison Papers, School of Arts and Sciences, Rutgers University
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