Note 18 — PREFACE TO THE SEVENTH EDITION. (continued 40)

Mr. Sharpe, in his work on “Decorated Window Tracery,” goes back one step, to the occurrence of a round window in the apex of a semi-Norman façade, over two round head-lights. If we were in search of what might suggest tracery, we might go back still further, to the panels often occurring, even in early Norman triforium arcades, as at Rochester; and sometimes, as at Peterborough, in groups of three or four, and deeply sunk.