After the removal of the library had been completed, with the assistance of Messrs. Watts and Bullen, the next important task was the preparation of the rules for the new catalogue, in which it is probable that Mr. Jones took the largest share. They were prepared under Mr. Panizzi's chief direction, with the co-operation of Messrs. Jones, Watts, Parry, and Edwards. The extent of time devoted to them, and the extreme thoroughness of the discussion, appears from Mr. Parry's evidence before the Royal Commission of 1849, and Mr. Edwards's history of the British Museum. They were finally accepted by the Trustees and officially promulgated in July 1839. In one important respect, the rule to be adopted for cataloguing anonymous books, the judgment of the compilers was overruled by the Trustees, and this is the source of many of the criticisms to which the rules themselves have been subjected. As a whole, they have received almost universal approbation; and their merit is sufficiently established by the circumstance of their having formed an epoch in bibliography as the basis of all subsequent work of the same nature. Very much of the discrepancy of opinion as regards cataloguing results from the failure to distinguish between the requisites of large and small libraries. The present writer is bound to say that in his opinion the alteration introduced by the Trustees is justified by a consideration of which the Trustees probably did not think, its indirect effect in providing, in the case of anonymous books, some kind of a substitute for what was then, and is still, the great deficiency of the British Museum library, an index of subjects. The same remark applies to the adoption of the headings "Academies," "Ephemerides," and "Periodical Publications," the introduction of biographical cross-references, and other features of the catalogue, perhaps exceptionable in theory, but assuredly very convenient in practice.