Furthermore although the knowledge gained from actually existing weights, which have been gleaned from the ruins of Nineveh, Khorsabad, or Naucratis, may be regarded as positive and more or less exact, we are met by the difficulty that in the case of Egypt and Assyria, where there was no coined money, we have no means of deciding what class of weight was used for certain kinds of commodities. In Greece and in the countries which formed the Persian empire we can be sure at all events of the standards which were employed in the weighing of gold and silver: the absence of this test is a serious hindrance in the study of Egyptian and Assyrian metrology. It is easy to illustrate by a supposed example the element of uncertainty introduced. Let us suppose that in ages to come the ruins of some English ironmonger’s shop were excavated, and a series of weights was found therein, a set of Avoirdupois weights ranging from a one-hundredweight to half an ounce; a set of Troy weights ranging from one pound to half a grain, and one of Apothecaries’ weights consisting of ounces, drachms, scruples, and grains. Suppose likewise that some ardent metrologist of that age, in addition to this splendid find, should be able to add to his material from elsewhere one or two sovereign and half-sovereign weights, a guinea, half-guinea, quarter-guinea, and seven-shilling-piece weight, perhaps even a noble, or a half-noble weight, and then without consulting literary sources, or previously studying the standards on which the English coinage had been struck at different periods, proceeded to reconstruct the metrological system of England. It is needless to say that his conclusions would be indeed widely aberrant from the truth. Having thus sketched however roughly some of the difficulties which beset our path, and after warning the reader that in metrology if anywhere the maxim of the old Sicilian poet is to be observed, Sober keep, to doubt inclined be; Hinges these are of the mind[292], I shall now proceed to set forth the method in which I conceive the various systems gradually rose and expanded. Let us bear in mind the fact already proved that gold was the first of all commodities to be weighed, and that consequently the standards employed for weighing that metal are the most archaic. EGYPT.