[LB007582], Letter from Richard Nott Dyer to Thomas John Handford, June 27th, 1882


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[LB007582], Letter from Richard Nott Dyer to Thomas John Handford, June 27th, 1882

Editor's Notes

I now wish to acknowledge the receipt of your several letters and to reply to them in detail.##Your letter of April 10th was received in due course.##Case 4[0] The drawings and additional specn have been forwarded. The claims seem now to be agreed upon. I thank yiu much for your clear explanation of the effect of adding modifications in complete not set forth [print]. In my amendatory paper in Case 43, I didn't make the change at head of 6th page suggested by you. Verbal changes of that character I expect you come to make when you consider that the specn will be in every respect improved by the change.##Your letter of april [19]th was also received in due course.##Case 44 The end [bars] D may be attached to plates C by screws. Plates C are set into grooves in the [under part] as shown. There need be no special attachment of plates C to [core] it.##In regard to the prints forwarded, you will have to understand the process by which they are made in order to be able to read the drawing readily.##We take thick paper and cover the surface with a mixture of [ferrocyanide] of potassium, iron citrate of ammonia, and water which is allowed to dry in a dark [vacum]. The tracing on linen, which we preserve of N. S. drawings, are placed upon this sensitized paper, and the whole exposed to the sun. Wherever the sensitized paper is not protected by ink upon the tracing, its surface is fixed (made insoluable in water), but where protected by ink the surface remains soluble in water and surface where it has been protected by the ink of the traping is removed. Hence the white spaces on your blueprint of case 44 are black ink spaces on our drawing and should be so on yours. There spaces represent insulation and they occur in figure 2 between the plates C and also between the bars B.##I think the claim you propose all right The end connecting bars are quite essential##Cases 45 and 46.##I have forwarded [addln] drawing and specn in one case an an addln specn in the other. I will [consider] the claims settled in [---] hence with your letters under consideration.##Your letter of April 18th was also duly received.##Case 48##I have noted the hange made by you in the title. The Continental Case was forwarded to mr Batchelor on the 12th of this month.##In connection with this matter, I wish to call your attention to mr Edison's prior patent 3894-80 and Siemans's patent 5[83]-80. I wish also to call your attention to the 9th claim, as one which I think is described in mr Edison's prior patent, but which mr Edison wanted me to put into this case. mr E. argues that no particular arrangement of the generators is described in that patent. The arrangements of the generators however is not per se [---] but may be [new] in this connection.##Your letters of 18th and 19th of april in regard to private business were also duly received. The special business which occasioned my writing you on this subject has been deferred. I may write you again in regard to the matter.##Your letter of April 20th was also duly received.##Case 47##I am having an extra drawing made, and will furnish additional description and write yu in detail in a day or two.##I have also received your letter of 2[1] ult. The list of patents has been forwarded##Cases 49 and 49a.##Mr Edison has seen your letter explaining the reasons for dividing the case. I have also received your letter of 18th ult relating to the same matter, but find that I cannot answer it fully without additional sketches from mr Edison. He has promised to furnish them.##Your letter of 12th inst in regard to case of [Stern and Bylleaby] has been received.##Claim 1 in this case is very important, and I know at [---] anticipation. Mr Edison's [N. S.] patent 218,167 dated Aug. 5 '79 is the nearest approach we have been able to find. Please refer me to the patent or publications upon which you base your advice to [erase] this [claim.] With reference to the springs resting on the dynamo commutator, flat springs or those having a slight curve, are used, the sides of the springs near the 2nd [resting] on the commutator so that there will be no danger of catching the ends of the springs on the edge of the commutator




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