Opus number developed other catalogue-number systems; among them the "Bach-Werke-Verzeichnis" (BWV-number), and the "Köchel-Verzeichnis" (K- and KV -numbers) with which are organised the works of Johann Sebastian Bach and Wolfgang Amadeus Mozart, respectively. In the classical period, the Latin word "opus" ("work", "labour") was used to identify, list, and catalogue a work of art. By the 15th and 16th centuries, the word "opus" was used by Italian composers to denote a specific musical composition, and by German composers for collections of music. In compositional practise, numbering musical works in chronological order dates from 17th century Italy, especially Venice. In common usage, the
K. Rudzki i S-ka remainder in the hands of Alfred Czarnomski, Władysław Mazurowski and Józef Korycki. Since then the company started to expand rapidly. In 1879 there were 221 workers employed in Rudzki's Warsaw works, by the end of the 19th century the number rose to 890, while value of production rose from 180,000 roubles to 2,132,000 roubles. In 1892 the company was also formally transformed into a joint stock company. Initially the K. Rudzki i S-ka benefited from fast industrialisation of the Kingdom of Poland. In 1881 it obtained a patent for an innovative method of piping production, which allowed it to become