Complex sentence: By 1847 the town had grown to a thousand persons served by the new church of St. George, built in 1840, the great majority of the men working in the copper mines with others employed in fishing and subsistence agriculture.
Split into simpler sentences: By 1847 the town had grown to a thousand people, served by the new church of St George, built in 1840. The great majority of the men worked in the copper mines with others employed in fishing and subsistence agriculture.