and there can be no question that it is distinctively an Anglo-Norman institution. Whether, however, it is English or Norman in origin and how it came into existence, are still in many respects obscure questions. The exchequer is not an innovation of Henry II, for the surviving roll of Henry I and certain incidental evidence show that it existed on both sides of the Channel in the reign of his grandfather. In the time of the author of the Dialogue there was a tradition that it had been imported from Normandy by William the Conqueror, but this must be discounted by the fact that certain elements of the system can be traced in Anglo-Saxon England. The truth is that the exchequer is a complicated institution, some parts of which may be quite ancient and the results of parallel development on both sides of the Channel; at least the problem of priority has reached no certain solution. Its most characteristic feature, however, its peculiar method of reckoning, does not seem either of Norman or English origin, but derived from the abacus of the ancient Romans, as used and taught in the continental schools of the eleventh and twelfth centuries.
One who tries to perform with Roman numerals a simple problem in addition or subtraction—or better yet, in multiplication or division—will have no difficulty in understanding why people unacquainted with the Arabic system of notation have had recourse to a counting-machine or abacus. The difficulty, of course,
