“I want you to make yourself as familiar as possible with the books,” said Mr. Townsend. “Here is a catalogue, and I have marked on it just what part of the store each book is in. The price of each book is written on the upper right-hand corner of the first fly-leaf, but as it is in letters, instead of figures, you will have to learn what the letters mean.” Tom thought it was a queer plan to mark the selling-price in letters instead of figures, but he was soon enlightened. “That is done so customers will not know the prices of books,” said his employer. “I take a word of ten letters, and each letter represents a figure from 1 to 0. Then, by combining the letters I can make any figure I want. Do you understand?” Tom said that he did, and he had soon mastered the little problem so that he could, after a little study, tell the selling-price of any book, by looking at the small letters on the first page. The book store was quite a large one. Tom had never seen so many volumes in one room before, except in a library, and he began to think he had come to just the right place, for he was fond of reading and study, and he made up his mind he would have a good time perusing his favorite volumes. But if our hero had an idea that clerks in book stores spend their time pleasantly in looking at pictures and reading stories, he was soon disappointed. He found himself ordered here and there by the other clerks. He had to bring books from the front of the store to the back, and from the back to the front. He had to get out bundles of wrapping-paper, and balls of twine. He had to dust off long rows of volumes, and when a clerk was trying to wait on two customers at once, Tom had to tie up books to be sent to various addresses given by the purchasers. The lad hoped he would be sent out to do some delivering, but he learned that the volumes went by a local express company, with which Mr. Townsend had a yearly contract. Tom was in the back part of the store, arranging some pamphlets that had been scattered about, when he saw an elderly gentleman walk slowly along the aisle formed by the book tables, and pausing before some historic volumes, take one from the row on the shelves. “Ha! Um! Here it is!” exclaimed the old gentleman, as he peered through his spectacles at the printed page. “I knew I was right. It isn’t there! Here, boy!” he called suddenly, glancing over the tops of his glasses at Tom. “Just you hold this book open a minute, right there, and keep your finger on this line,” and he held the volume out to the lad. Wonderingly, Tom complied. The queer customer ran his finger along the row of books, took out another, leafed it over rapidly, and uttered an exclamation. Then, placing this book down on a table, and holding it open with one hand, he reached for a third volume, which he extended to Tom. “Open that at page twenty-one,” he said. “I can’t,” replied the boy, “unless I let go of this other book.”