The abolition of the guilds cleared the way for the technical changes that had just begun and the development of which was yet in the future. These changes may be summarized as the application of science to industry and the introduction of machinery. The process went on in France irregularly, affecting different industries and different localities in various degrees. The first machine (_machine à vapeur_) was introduced in France about 1815; in 1830 there were about 600 in operation. Some idea of the later changes may be gained from the following table giving the number of machines in France from 1839 to 1907: _Year_ _No. of Machines_ _Total Horsepower_ 1839 2,450 33,000 1851 5,672 71,000 1861 15,805 191,000 1871 26,146 316,000 1881 44,010 576,000 1891 55,967 916,000 1901 75,866 1,907,000 1910 82,238 2,913,013[3] [3] _Annuaire Statistique_. The introduction of machinery meant the absorption of a larger part of the population in industry, the concentration of industry in a smaller number of establishments and the absolute and relative increase in the numbers of the working population of France. This class of the population was regulated in its economic action for nearly a century by another law passed June 14-17, 1791, and known by the name of its author as the law Le Chapelier. The law Le Chapelier, though dictated by the same general interests and ideas as the law on the guilds, was made necessary by special circumstances. The abolition of the guilds had as one of its effects an agitation among the journeymen for higher wages and for better conditions of employment. During the summer of 1791, Paris was the scene of large meetings of journeymen, at which matters of work and wages were discussed. The movement spread from trade to trade, but the struggle was particularly acute in the building trades. Profiting by the law of August 21, 1790, which gave all citizens the "right to assemble peacefully and to form among themselves free associations subject only to the laws which all citizens must obey,"[4] the carpenters formed _L'Union fraternelle des ouvriers en l'art de la charpente_, an association ostensibly for benevolent purposes only, but which in reality helped the carpenters in their struggle with their masters. The masters repeatedly petitioned the municipality of Paris to put an end to the "disorders," and to the "tyranny" of the journeymen. The masters complained that a general coalition of 80,000 workingmen had been formed in the capital and that the agitation was spreading to the provincial towns.[5] The municipal authorities tried to meet the situation, but their "notices" and "decrees" had no effect. They then appealed to the Constituent Assembly for a general law on associations and combinations. The result was the law Le Chapelier.