My Lord Marquis, Your Lordship’s most devoted And most faithful, humble Servant, HENRY O’BRIEN. LONDON, _September 1834_. LIST OF ILLUSTRATIONS. PAGE PORTRAIT OF HENRY O'BRIEN, BY MACLISE _Frontispiece_ DEVENISH ROUND TOWER 38 ARDMORE " " 71 CLONDALKIN " " 101 EFFIGY OF FARRAGH, OR MORIAGAN 138 SAMONA OF BUDDHA 140 ROUND TOWER, WITH DEVOTEE ON SUMMIT 169 SYMBOLIC SCULPTURE FOUND AT VINDOLANA 223 PALENCIAN SCULPTURE OF THE SYMBOLIC “TREE,” WITH FIGURES 229 PYTHAGOREAN TRIANGLE OF TEN 268 SYMBOLIC CRESCENT-ORNAMENTS 273, 274 EFFIGY OF CRUCIFIED BUDDHA, SACA, OR MACHA 296 BRECHIN ROUND TOWER (SCOTLAND), WITH DOUBLE-ARCH AND EFFIGIES 299 OBELISK AT SANDWICK (ROSS-SHIRE) 306 PHOENICIAN MEDALS, STAMPED WITH CROSS, LAMB, AND ROSARY 314 SHAFT OF CROSS AT FORRES (SCOTLAND) 316 " " " REVERSE SIDE OF SAME 319 MONOLITH AT CARNAC (EGYPT) 322 SCULPTURE IN KNOCKMOY ABBEY 329, 330 SCULPTURE ON TEMPLE AT KALABCHE (NUBIA) 341, 342 KILCULLEN, CROSS AT 338 CLONMACNOISE, " 358 FINGLAS " 366 KELLS " 491 FACSIMILE OF MS. DISCOVERED AT ICOLMKILL 419 PHEELEAS, OR ORACLE-TUBE, FOUND AT BALLYMONEY 460 GLENDALOUGH, CURIOUS SYMBOLIC SCULPTURE ON RUINS OF 467 THE MAGI--WOODCUT FROM AN ANCIENT BLOCK-BOOK 482 MEDALS OF CHRIST, FOUND AT ISLAND OF ANGLESEA AND AT CORK 509 THE ROUND TOWERS, _&c._ CHAPTER I.