[M] See Fig. 20, p. 63. There is but one exception, in the case of a recent exploration, during which one solitary broken column-shaft was discovered. [N] G. Rawlinson's "Five Monarchies," Vol. I., pp. 467, 468. [O] See Fig. 33, p. 83. [P] Figures 34 and 35, p. 84. [Q] Figs. 37 and 38, p. 87. [R] Fig. 39, p. 89. [S] See Fig. 59, p. 217. [T] See Figs. 44 and 45, p. 101. IV. THE BOOK OF THE PAST.--THE LIBRARY OF NINEVEH. 1. When we wish to learn the great deeds of past ages, and of mighty men long dead, we open a book and read. When we wish to leave to the generations who will come long after us a record of the things that were done by ourselves or in our own times, we take pen, ink and paper, and write a book. What we have written is then printed, published in several hundreds--or thousands--of copies, as the case may be, and quickly finds its way to all the countries of the world inhabited by people who are trained from childhood to thought and study. So that we have the satisfaction of knowing that the information which we have labored to preserve will be obtainable any number of years or centuries after we shall have ceased to exist, at no greater trouble than procuring the book from the shelves of a bookstore, a public or a private library. It is all very simple. And there is not a small child who does not perfectly know a book by its looks, and even has not a pretty correct idea of how a book is made and what it is good for. 2. But books are not always of the shape and material so familiar to us. Metal, stone, brick, walls and pillars, nay, the very rocks of nature's own making, can be books, conveying information as plainly as our volumes of paper sheets covered with written or printed lines. It only needs to know how to read them, and the necessary knowledge and skill may be acquired by processes as simple as the art of ordinary reading and writing, though at the cost of a somewhat greater amount of time and pains.