D O C . 2 1 O P I N I O N A N S C H Ü T Z V S . K R E I S E L B A U 1 9 5
1) Der Drexler-Steuerzeiger fällt in den Bereich des Patentes 301738.
2) Er bedeutet keine blosse Nachahmung oder Umgehung des Gegenstandes je-
nes Patentes, sondern eine „abhängige Erfindung“ (im Sinne der obigen Definition)
inbezug auf den Gegenstand, soweit er in
jedem[8]
Patente dargelegt ist.
Zürich, 23. Juli 1919.
gez. A. Einstein
TTrD (GyMDM, Nachlass Lachmann, NL 180/003). [85 062]. The document consists of eight pages,
all but the first of which are numbered. The presentation of the page numbers here—in the margin in
square brackets—departs from that in the original, where page numbers “2” through “8” appear typed
at the head of the respective page. The document was prepared by Einstein but almost certainly not
typed by him. The figures in the document are drawn in another hand. The document is marked
“Copy” (“Abschrift”) at the head of the first page, and addressed “Justizrat Dr. Seligsohn I, Rechtsan-
walt u. Notar, Justizrat Seligsohn II Rechtsanwalt, Berlin N.W.7, Prinz-Louis-Ferdinandstr. 1.” Hand-
written typographic corrections, though not in Einstein’s hand, are incorporated in the transcription.
Lohmeier and Schell 1992, pp. 245–251, presents the transcription of a slightly different manuscript
[35 392]. Significant variations between the text and the manuscript are noted. On the verso of the
second page of the manuscript [35 392] is a handwritten draft for the summary of Einstein’s lecture
to the Prussian Academy of Sciences of 15 May 1919 (see Doc. 17, note 1, for the text of the sum-
mary).
[1]Court expert opinions, as distinct from private expert opinions, were impartial opinions solicited
by courts on technical questions from experts who were required to attend the proceedings and to pro-
vide oral testimony (see Seligsohn 1920, p. 399).
[2]Kreiselbau Co. was owned by Franz Drexler, who had worked at Anschütz & Co. in developing
his own design for a gyrocompass. When Drexler left and attempted to produce and sell the design
through his newly founded company, Anschütz brought suit. For further background on Einstein’s
involvement in the dispute between Anschütz and Drexler, see Lohmeier and Schell 1992, pp. 29ff.
[3]At this point in the draft, Einstein deleted the following phrase: “welche zugleich die wichtigsten
Bestandteile der Drexler’schen Apparatur sind.”
[4]Deutsches Reichspatent 301738, entitled “Anzeigevorrichtung für die Drehungen eines Flug-
zeuges um die senkrechte Achse,” was granted on 25 March 1917 to Anschütz & Co.
[5]Deutsches Reichspatent 262409, entitled “Vorrichtung zur Stabilisierung von Luftfahrzeugen,
insbesondere Flugzeugen, mittels eines Kreiselpendels,” was granted on 12 July 1913 to Louis Mar-
monier; Deutsches Reichspatent 267061, entitled “Lagenanzeiger für Flugzeuge mit vor einem Ska-
lenblatt liegenden Zeigern für Angabe der Längs- und Querneigung,” was granted on 11 November
1913 to Wilhelm Wolfromm; Deutsches Reichspatent 286217, entitled “Selbsttätiger Kreiselstabili-
sator für Flugzeuge,” was granted on 28 July 1915 to Edmund Sparmann.
[6]Arnold Seligsohn (1854–1939) was a patent lawyer and the legal expert of Kreiselbau Co.
[7]In the draft: “Erster.”
[8]In the draft: “jenem.”