THE true key to the Domesday Survey, and to the system of land assessment it records, is found in the Inquisitio Comitatus Cantabrigiensis. Although the document so styled is one of cardinal importance, it has, from accident, been known to few, and has consequently never succeeded in obtaining the attention and scientific treatment it deserved. The merit of its identification belongs to Mr. Philip Carteret Webb, who published in 1756 a paper originally read before the Society of Antiquaries, entitled, A Short Account of Danegeld, with some further particulars relating to William the Conqueror's Survey. It is difficult to speak too highly of this production, remembering the date at which it was composed. Many years were yet to elapse before the printing of Domesday was even begun, and historical evidences were largely inaccessible as compared with the condition of things to-day. Yet the ability shown by Mr. Webb in this careful and conscientious piece of work is well seen in his interesting discovery, which he announced in these words:–