[D8238ZBX], Letter from Charles Batchelor to Thomas Alva Edison, July 17th, 1882


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[D8238ZBX], Letter from Charles Batchelor to Thomas Alva Edison, July 17th, 1882

Editor's Notes

Confirming telegram last night for 5000 bulbs and enough glass to complete as many lamps. Have struck a "bug" which seems to be in glass of all best mfgs: "One of the wires in the inside part becomes black in the inside of glass. It is always the same wire as if it was an action like a plating action. I have tried for it in everything and I think it must be in the glass. I therefore ordered the 5000, if I find it is something else we can always use the glass. I have had a great deal of trouble with the glass men here and when I have got them just where I want them I have struck this bug." [TAE marg: "You will find it is blackening of the platina wire on one pole in all lamps made by us that had run for some time. What [crosswriting] this bulb [---] coming from [---] make thickest glass in the world [illeg few words]"]. Finished 6 Z dynamos, 28 more almost done and 100 more well under way. Started 2 big dynamos and want to know which engine to order for them. [TAE marg: Armington &Sims 175 hp going up to 250 price is about 1850 @ 1875."] Leaky mercury tubes: this caused us lots of trouble at MP but I've struck something that has killed all leaks in tubing for 600 pumps: put no washer under flange of mercury cock [sketch] but screw it in to within a 1/16 inch of should then lap it, then soak with shellac in alcohol--"it makes a most perfect mercury joint. [TAE marg: Send this to pat Upton."] Have cast socket mould of type metal; work well [drawing]. Made all my safety catches Plaster Paris--cheap; didn't you do this? [TAE marg: "Send this to Bergmanns & EHJ]. Screwing bolts: made a good strike using Brown screwing machine forbolts to cut keeper bolts and head screws. [TAE marg: "We have the large Buffalo bolt machine 1 $8 boy cuts all the bolts used in shop."] Let me know your opinion on some of these things. [nice clear sketches of Batch's innovations, too]




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