No christening entry has been found for this John Hattam. There are some suitable "gaps" in the known children of William & Ann, for instance 1688 and 1693. If the birth had been 1688, then he might well have been named Thomas Hattam, as a later child christening in 1691 was. So the presumption is that he was born around 1693. This makes him 22 years old when he marries Mary Bohemia in 1715, and thus 35 years old at the christening of his youngest known child in 1728.