Who is Henry Jacobi from The Engines of God and what is their importance?

Henry Jacobi is described as a homely man with a creased face and sagging anatomy. He has gray hair and always seems to be squinting, possibly a result of the countless hours he's spent staring at ideographs. Contrary to his appearance, Henry is a master of the social graces, and is well liked by everyone. He is a consumate professional and seems able to construct an entire culture based on a single urn. Henry understands the importance of saving Quraqua, but he feels that he is too old to be risking anyone's life to do so.