Contiene índice: 69-70 p.

"With eleven facsimiles in collotype." --Port.

"This edition is limited to 500 copies."

I. Author's corrections -- II. The significance of cancels -- III. The printing and placing of cancels-simple deletion -- IV. Cancels and watermarks -- V. Other precautions against oversight -- VI. Cancels and watermarks -- VII. The detection of cancels -- VIII. The discovery of cancellanda -- IX. Miscellaneous examples -- Appendixes : Cancels distinguishing issues -- Fraudulent cancellation -- Addendum -- Index. "By a cancel I understand a leaf or leaves (sometimes part of a leaf) intended to be substituted for the corresponding part of a book as originally printed. An additional leaf, such as was sometimes printed for insertion in a sheet, or between sheets, is not strictly a cancel. A sheet found to be so faulty as to defy partial amendment, and therefore reprinted as a whole, would properly be said to be cancelled. (...) For bibliography, and for historical criticism, the words 'intended to be substituded' are an importat element in my definition." --p. 5