  The first electron-positron collisions in a laboratory were observed in
1963-1964 at the Laboratoire de l'Acc\'el\'erateur Lin\'eaire d'Orsay, in
France, with the storage ring AdA, which had been constructed in the Italian
National Laboratories of Frascati in 1960, under the guidance of Bruno
Touschek. The making of the collaboration between the two laboratories included
visits between Orsay and Frascati, letters between Rome and Paris, and
culminated with AdA leaving Frascati on July 4th, 1962 to cross the Alps on a
truck, with the doughnut degassed to $10^{-9}$mmHg through pumps powered by
sets of heavy batteries. This epoch-making trip and the exchanges which
preceded it are described through unpublished documents and interviews with
some of its protagonists, Carlo Bernardini, Francois Lacoste, Jacques
Ha\"issinski, Maurice L\'evy.
