This last case makes it especially clear that the object was to make the shares on the same pattern in point of quality, and not of mere quantity. It is only to be regretted that manorial surveys, hundred rolls, and other documents of the same kind take too little heed of such variations, and consider the whole arrangement merely in regard to the interests of the landlord. For this purpose a rough quantitative statement was sufficient. They give very sparing indications as to the facts underlying the system of holdings; their aim is to reduce all relations to artificial uniformity in order to make them a fitter basis for the distribution of rents and labour services. But very little attention is required to notice a very great difference between such figures and reality. In most of the cases, when the virgate is described in its component parts, we come across irregularities. Again, each component part is more or less irregular, because instead of the acres and half-acres the real ground presents strips of a very capricious shape. And so we must come to the conclusion, that the hide, the virgate, the bovate, in short every holding mentioned in the surveys, appears primarily as an artificial, administrative, and fiscal unit which corresponds only in a very rough way to the agrarian reality. [Acre ware.] This conclusion coincides with the most important fact, that the reckoning of acres in regard to the plough-team is entirely different in the treatises on husbandry from what it is in the manorial records drawn up for the purpose of an assessment of duties and payments. Walter of Henley and Fleta reckon 180 acres to the plough in a three-field system, and 160 in a two-field system. Now these figures are quite exceptional in surveys, whereas 120 acres is most usual without any distinction as to the course of rotation of crops. The relation between the three-field ploughland of 180 acres and the hide of 120 suggests the inference that the official assessment started from the prevalence of the three-field rotation, and disregarded the fallow. But the inference is hardly sufficient to explain the facts of the case. The way towards a solution of the problem is indicated by the terminology of the Ely surveys in the British Museum. These documents very often mention virgates and full yardlands of twelve acres _de ware_; on the other hand, the Court Rolls from Edward I's time till Elizabeth's, and a survey of the reign of Edward III, show the virgate to consist of twenty-four acres[485]. The virgate _de ware_ corresponds usually to one-half of the real virgate; I say usually, because in one case it is reckoned to contain eighteen acres in the place of twenty-four mentioned in the rolls and the later survey[486]. Such 'acre ware' are to be found, though rarely, in other manors besides those of Ely minster[487]. The contradiction between the documents may be taken at first glance to originate in a difference