Every fifty years commences a discussion of the great question when the current century, or half century, properly begins. We have just seen this in the numerous Queries, Answers, Replies, and Rejoinders upon the subject which have appeared in the columns of the daily and weekly press; the only regular treatise being the essay upon _Ancient and Modern Usage in Reckoning_, by professor De Morgan, in the _Companion to the Almanack_ for the present year. This Essay is opposed to the idea of a "zero year," and one of the advocates of that system of computation has, therefore, undertaken a defence of the zero principle, which he pronounces, "when properly understood, is undoubtedly the most correct basis of reckoning," in a small volume entitled, _An Examination of the Century Question_, and in which he maintains the point for which he is contending with considerable learning and ingenuity. All who are interested in the question at issue, will be at once amused and instructed by it. Mr. Charles Knight announces a new edition of his _Pictorial Shakespeare_ under the title of the National Edition; to contain the whole of the Notes, Illustrations, &c., thoroughly revised; and which, while it will be printed in a clear and beautiful type across the page, and not in double columns, will have the advantage of being much cheaper than the edition which he originally put forth. _The Declaration of the Fathers of the Councell of Trent concerning the going into Churches at such Times as Hereticall Service is said or Heresy preached, &c._, is a reprint of a very rare tract, which possesses some present interest, as it bears upon the statement which has been of late years much insisted on by Mr. Perceval and other Anglican controversialists, that for the first twelve years of Elizabeth's reign, and until Pius V.'s celebrated Bull, _Regnans in Excelsis_, the Roman Catholics of England were in the habit of frequenting the Reformed worship. We have received the following Catalogues:--W.S. Lincoln's (Cheltenham House, Westminster Road) Sixty-first Catalogue of English and Foreign Second-hand Books; W.D. Reeve's (98. Chancery Lane) Catalogue No. 13. of Cheap Books, many Rare and Curious; R. Kimpton's (31. Wardour Street, Soho) Catalogue No. 29. of Second-hand Books in good Condition at very reduced Prices. * * * * * BOOKS AND ODD VOLUMES WANTED TO PURCHASE. CAMBRIDGE UNIVERSITY POLL-BOOKS FOR 1780, 1784, 1790, and 1829. OXFORD UNIVERSITY POLL-BOOKS for 1750, 1768, 1806. BEN JONSON by CLIFFORD. 8vo. Vols. II., III., and IV. Letters, stating particulars and lowest price, _carriage free_, to be sent to Mr. BELL, Publisher of "NOTES AND QUERIES," 186. Fleet Street. * * * * * NOTICES TO CORRESPONDENTS. VOLUME THE FIRST OF NOTES AND QUERIES, _with Title-page and very copious Index, is now ready, price 9s. 6d., bound in cloth, and may be had, by order, of all Booksellers and Newsmen._