ticularly indebted to Deputy Clerk Harold B. Willey, and to Assistant Clerk Edmund P. Cullinan. Other members of the Clerk's staff, the Marshal, Thomas E. Waggaman, and the Librarian, Miss Helen Newman, although bothered to a lesser extent, have been equally courteous and cooperative.
The authors also appreciate the willing assistance and suggestions of their colleagues and friends, and of the staff of the publisher. At least one of them is especially grateful to his wife, Terese M. Stern, who, in addition to her many household duties, managed to translate his handwritten manuscript into a form intelligible to the publisher.
Washington, D. C.
May 29, 1950.