 Not long after, Black bought out his partners and ownership of the "Britannica" passed to the Edinburgh publishing firm of A & C Black.Britannica by the 6th edition was in some regards hopelessly out of date.The supplement to the 3rd edition contained updates which were not included in it, and which had become dated themselves anyway, the 4th edition expanded the text somewhat but revised very little, and the 5th and 6th were just reprints of the 4th.