The Commonplace Book is Cambridge University MS Dd.ix.44, which is described as follows in A Catalogue of the Manuscripts Preserved in the Library of the University of Cambridge (University Press, Cambridge, 1856) Vol. I p.403; item 531.

531             Dd. ix. 44.

A folio, on paper, of 188 leaves, in double columns.
A Common-place Book, chiefly filled with Geographical and Historical notes and references.

On the first page is the note,
“This MS. is in the Handwriting of Mr John Smith sometimes Fellow of Queens Coll. in Cambridge, Author of several Discourses published after his death by my Father.’ [J. Worthington.]