Thanks for posting the info - I'll have to see if the library here has that book. However, there are a few errors that I see already.
William was the son of Zadock Ingell, not Seth - although he had a brother Seth that died young.
I have from Chester, MA vital records that William married Esther Whittemore on Aug. 1, 1813 (they were half-1st cousins).Perhaps the Apr. date was the intention.I also found a date of Sept. 21, 1813 Middlefield, MA, so maybe none of these are correct!
And finally, William was the 4th (poss. 5th) of 7 children, unless the possible dates I have for his sister Eliza are all wrong and she was actually a year or two older than him.
Most of the descendants of William & Esther are through their first daughter Sarah Sophia (Ingell) Parker.