“…There are numerous papers dealing with the production of free time scales [Winkler et al, 1970;Allan et al, 1974;Bureau Internationale de l'Heure, 1974;Hiibner and Becker, 1974;Angeli, 1975] or dealing with steering of them Guinot, 1975;Azoubib et al, 1977;Becker, 1977a;Granveaud and Azoubib, 1978;Yoshirnura, 1973], the purpose usually being to optimize the respective calculations, especially the allocation of weights to the clocks.…”