 These activities were most successful in Petersburg and Odessa, where the circles comprised around 400 workers.Some of these workers—including Viktor Obnorsky and Feodor Kravchenko—would later become the founders of the first proletarian organizations such as the Worker's Union of Southern Russia (Южнороссийский союз рабочих) and Northern Union of the Russian Workers (Северный союз русских рабочих).The results of this propaganda work were summarized in a report by Peter Kropotkin, which would be discussed in the Petersburg circle of the Tchaikovtsy in late 1873.