the royal decree allowed each voivode to create and maintain a single system used in his voivodeship. This law was later confirmed by a Sejm act of 1565. Steel or copper rods used as local standard of ell (basic unit of length) were created in a voivode's capital and then dispatched to all nearby towns, where they were further duplicated for everyday use. One bar was to be stored in the town hall for comparison, while additional rods were stored in the gatehouses or toll points to be borrowed by merchants as needed. Damaging or losing a rod was punishable by law. Measuring time Outside of this set of systems was the measurement of time. As clock towers only started to appear in late Middle Ages, and their usability was limited to within a small radius, some basic substitutes for modern minutes and hours were developed, based on Christian prayers. The pacierz (or paternoster) was a non-standard unit of time comprising some 25 seconds, that is enough time to recite the Lord's Prayer. Similarly, zdrowaśka (from Zdrowaś Mario, the first words of the Hail Mary) was used, as was the Rosary (różaniec) that is the time needed to recite Hail Mary 50 times (roughly 16 minutes). Those units were never strictly defined, but is used in rural areas of Poland even today. Early attempts at standardisation While this system introduced some level of standardisation throughout the country, the systems used in various voivodeships still differed from one another. To counter this problem the Kraków ell and Poznań ell were made equal in 1507. The same applied to ells used in Lwów and Lublin, which however were different from those in Kraków and Poznań. In 1532 the Płock ell was aligned with the Kraków ell, which in 1565 was declared an official ell to be used in all of the Crown of Poland. The system used by Warsaw was adopted in Płock and all of Masovia in 1569. In 1613 additional systems were created for Vilnius and Kaunas. The standardisation of other units of measurement also made some progress since the 15th century, but at a different pace. In the end this created even more confusion, as two towns could use the same units of length, but two different units of weight, although using the same terms. 1764 reform - the Old Polish system As until then not only different units