German physicist who was the first to satisfactorily demonstrate the existence of electromagnetic waves by building an apparatus to produce and detect VHF or UHF radio waves. ALS signed “H. Hertz,” one page, 5.25 x 8.25, October 27, 1891. Letter to astronomer Henry Crew. In part: “By the same post I send you a set of the required papers. You will only find the first paper wanting…I give you my best thanks for the publication of the Observatory which you sent me.” In fine condition. Accompanied by the original mailing envelope. RRAuction COA.
