Massachusetts Institute of Technology (MIT): Cambridge (MA), 1926.  First Edition.

Two series of lectures on The Structure of the Atom (20 Lectures) and The Lattice Theory of Rigid Bodies (10 Lectures).

"These lectures represent perhaps the most vivid written record of the transition between the 'old' quantum theory of Bohr, and [Heisenberg's] 'new' theory."

Gilt spine text a little dulled, otherwise a truly fine copy.