Complex sentence: Jonathan Elliot was a building contractor and two of his sons, Edward and Henry, became architects, their father helping build at least one of their buildings, the Mechanics Institute, in 1843 in Dartmouth.
Split into simpler sentences: Jonathan Elliot was a building contractor and two of his sons, Edward and Henry, became architects. Their father helping build at least one of their buildings, the Mechanics Institute, in 1843 in Dartmouth.