The report from which these figures are taken was made in furtherance of the good and fruitful suggestion that a great Reading-Room should be built within the inner quadrangle. Judging from the past, argued Mr. PANIZZI, in June, 1852, ‘and supposing that for the next ten years from seven thousand to seven thousand five hundred pounds will be spent in the purchase of printed books, the increase ... would be at the average of about twenty-seven thousand volumes a year, without taking into consideration the chance of an extraordinary increase, owing to the purchase or donation of any large collection. [Sidenote: See hereafter, Chap. V.] It was owing to the splendid bequest of Mr. GRENVILLE that the additions to the Collection in 1847 reached the enormous amount of more than fifty-five thousand volumes. After the steady and regular addition of about twenty-seven thousand volumes for ten years together, here reckoned upon, the Collection of Printed Books in the British Museum might defy comparison, and would approach, as near as seems practicable in such matters, to a state of completeness. The increase for the ten years next following might be fairly reduced to two thirds of the above sum. [Sidenote: GROWTH OF THE PRINTED SECTION OF THE LIBRARY SINCE 1852.] At this rate, the collection of books, which has been more than doubled during the last fifteen years, would be double of what it now is in twenty years from the present time [1852].’ At the date of this report the number of volumes was already upwards of four hundred and seventy thousand. At the date at which I now write (January, 1870), the number of volumes, as nearly as it can be calculated, has become one million and six thousand. On the average, therefore, of the whole period, the increase has been not less than thirty-one thousand five hundred volumes in every year. The Collection was somewhat more than doubled during the first fifteen years of Mr. PANIZZI’S Keepership. During the next like term of years, when the department was partly under the administration of Mr. PANIZZI, and partly under that of Mr. Winter JONES, it was nearly doubled again. It follows that the anticipation expressed in the _Report_ of 1852 has been much more than fulfilled. Less than seventeen years of labour have achieved what was then expected to be the work of twenty years. If the other departments of the British Museum cannot show an equal ratio of growth during the term now under review, it has not been from lack of zeal, either in their heads or in the Trustees. Their progress, too, was very great, although it is not capable of being so strikingly and compendiously illustrated. It has also to be borne in mind that the arrears, so to speak, of the Library, were relatively greater than those of some other divisions of the Museum. [Sidenote: PROGRESS OF THE NATURAL HISTORY COLLECTIONS.]