Princeton, 6 March 1952

'We discussed scientific questions every day on the way home from the office': memories of his formative years.

Besso has asked for information to pass on to Carl Seelig for the latter's projected biography: Einstein is pleased to see that his early Swiss years will receive more attention, as at present people have the impression 'that I was born in Berlin!'. Besso should begin with the scientific discussions they shared on the way home from the Swiss Federal Patent Office, which gave birth to the special theory of relativity: 'It must be said that we discussed scientific questions every day on the way home from the office'. Einstein's friendships with Maurice Solovine and the brothers Conrad and Paul Habicht also deserve prominence – the former designed a machine which Einstein used for measuring tiny charges of electricity. The influence of David Hume should be underlined, as of Poincaré and Mach: it was Besso who introduced Einstein to the latter. He remembers the influence, for good or bad, of certain professors, including Aimé Forster at the University of Berne, 'about whose incompetence drastic tales were circulated amongst the younger people'. It was Professor Kleiner who was responsible for nominating Einstein to his position in Zurich: 'He came specially to Berne in order to hear me as a freshly-baked Privat-dozent (you and Chavan were my only audience). Subsequently he said, correctly, that it was not particularly good. I agreed, but observed mischievously that he was also not obliged to nominate me. He did it anyway, however'. He also mentions his close friend Marcel Grossmann, on the basis of whose excellent homework Einstein was able to pass his diploma, and with whom Einstein was later to work on general relativity.

On the subject of his current work, Einstein announces that he has 'made a quite decisive step forward in the generalisation of the general theory of relativity ... Until now the field equations for the non-symmetrical field were not unambiguously theoretically fixed. This inconvenience is now remedied through an extension of the group-characteristic for the field'. Einstein sets out the corresponding equations. 'In this enlarged group the old gravitational equations are no longer co-variant, although each of their solutions is a solution of the new system. The general field theory thus becomes just as convincing as the old gravitational theory. The physical testing of the theory is however not within sight...'.