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You have probably returned by now and received my letter. Here, we are now in the midst of great telephone hype! At the same time that [Postmaster General Heinrich von] Stephan received our models, he got a couple of American ones from the Englishman (a German-English fellow who was sent here), which work better than the one you produced and better than ours, too. It’s a matter of small construction details! Recently, during a dinner at Stephan’s home, some trials were conducted with them: with ours in the dining hall and with the American ones between the house and the main postal station. The latter functioned very well with two underground cables. Subsequently, voices and songs, etc., were transmitted quite nicely and clearly, first to Potsdam, then even as far as Brandenburg. Magdeburg was beyond reach though. It is now a fact that distinct voice transmission via a dual underground line is possible across ten German miles! That is surprising indeed. Stephan is really wild with excitement, and his officials, too. We are working hard right away, as the entire world wants to get hold of them. I have already commissioned improvements, which I expect will make quite a difference. Now begins the era of underground lines, and it would be very helpful if you devoted all of your attention to the construction of cheap (thin) cables. The day after tomorrow we are traveling to Kiel with Stephan and his entourage (among them an English engineer from the post office and a Millitzer from Vienna) to conduct speaking experiments between Kiel, Berlin, and Frankfurt. After that we are giving a dinner at Bellevue for about 40 guests, with the Provincial Governor and all top civil servants in attendance! The “Indian ink writer” and the new dual stylus (black surfaces exposed) work brilliantly. The latter produces 1,400 words per hour, safely and nicely. Success is at hand.

Stephan plans possibly to provide all Berlin residents with phone lines to each other!