German-born automotive manufacturer (1877–1932). TLS signed “F. S. Duesenberg,” one page, 8.25 x 10.75, Duesenberg, Inc. letterhead, August 16, 1927. Duesenberg writes to E. S. Palmbla at the North Chicago Machine Company. In full: “Your letter of August 12th received and beg to advise that we are always interested in new developments. About nine years ago, we built a motor which had a common intake and exhaust valve using a rotary distributor above. You will remember, no doubt, the motor was made by Mr. Able, which had a positive opening and closing device for this valve. The system we had was a little bit more efficient but possibly harder to construct. The bad part about all of these valves as we have seen is that some of the burnt charge is left in the port and mixes with the intake when it opens and goes back into the cylinder. Under certain conditions this is a decided advantage while in others it is not. If you had a sketch of your device so that we could see what it is like, it might be that you could overcome this. We still have the motor that we built and it had some decided advantages over the present type of motor but we have never thought well enough of it to continue experimenting with it. If we could get something good from you it might be well for us to take it up with you….” In 1915, Edward S. Palmbla received patent #1,130,014 for “a new and useful Improvement in Internal-Combustion Engines…. My invention relates to certain new and 10 useful improvements in internal-combustion engines….” Accompanied by photocopies of the retained carbon of Palmbla’s August 24th reply to Duesenberg, Duesenberg’s August 26th reply to Palmbla, the retained copy of Palmbla’s reply to Duesenberg’s August 26th letter, and Palmbla’s patent, including illustrations. In very good condition, with intersecting folds (touching last name; partial separations with archival reinforcement to reverse), wrinkling, and handling wear (including marginal pinholes). RRAuction COA.
