Some of the information in "The Book of Dow" on Joseph Dow and his second wife (parents of Eliphaz and Judah)has been refuted in an in-depth article on that Dow line written by George Freeman Sanborn Jr. in "The New Hampshire Genealogical Record."
It does not disagree with the line of descent being Joseph, Judah, Zaccheus, and Tristram (b. ca 1792), but some of the details vary, including the identity of Joseph's second wife. According to "The Book of Dow," it was Hannah, a child taken from her Indian parents with permission by a Seabrook Quaker family.The Freeman article identifies Hannah as Hannah Challis, sister of Joseph's first wife.Anyone descended from Joseph and his second wife should check into the information provided by Mr. Freeman.
The Freeman article does not have details on Tristram's marriage or children.
The 1850 census for Seabrook has both Tristram and Rachel, and also Sewell and Almira.