Note 2 — Chapter XXXVII · THE CONVICT MINES OF KARA.
Reading edition
According to the law of 1857 (Article 569), it appears that irons are worn during the time a prisoner is in the lowest category (or during probation time), after which they are continued as follows: for one condemned for life, 8 years: from 15 to 20 years, 4 years: from 12 to 15 years, 2 years: from 6 to 8 years, 18 months; and from 4 to 6 years, 12 months.