Complex sentence: On 13 August 1640 he was accepted into the Amsterdam masons' guild as a master, and on 3 December 1647 the city government appointed him master mason of the city ("stadsmeestersteenhouwer").
Split into simpler sentences: On 13 Augustus 1640 he was accepted into the Amsterdam masons' guild as a master. On 3 December 1647 the city government appointed him master mason of the city ("stadsmeestersteenhouwer").