There is also another consideration which is entitled to weight in this connection. Suppose Phidias to have commenced his artistic career four years after the battle of Marathon—in B. C. 490 (Olymp. 72·3). From that time to B. C. 444 (Olymp. 83·4), when he began the Athena of the Parthenon, there are forty-five years; and during this time he is supposed to have executed six colossal statues in bronze or acrolith,—two of which, the Athena Promachos and the Athena Areia, were from 50 to 60 feet in height—and one, the Athena Lemnia, was considered as perhaps his most beautiful work. Besides this, he executed thirteen statues at Delphi, the size of which is not stated. Nineteen statues in forty-five years give a little over 2⅓ years to each; and if the thirteen statues at Delphi were colossal, this will certainly seem insufficient for their execution, when we keep in mind the facts—1st, That Phidias was a slow and elaborate worker; 2d, That of necessity he must have done a great part of the work in bronze personally; 3d, That he was occupied four years on the Zeus alone; 4th, That two of these statues, at least, were larger than the Athena of the Parthenon, though not in the same material. It is, however, probable, that the thirteen statues at Delphi were not of colossal proportions, but rather of heroic size, and therefore requiring less time in their execution; and this would enable us to assign a longer time to the mighty colossi of Athena. Certainly, however, if we accept the theory that Phidias commenced working twenty-five years after the battle of Marathon, we are in very great straits as to time, unless the date when these colossal statues were made be incorrect, and unless some of them were made after the Athena of the Parthenon. This, again, we cannot accept; for, from the date of the completion of the Athena of the Parthenon until his death, there are only at most some seven years, four of which were dedicated to the Zeus. We are then forced to believe that these nineteen statues were made in twenty years; and this is certainly very improbable. In this view other difficulties also appear, which it would seem impossible to overcome, if we accept all the statues attributed to Phidias as having been executed by him; for in such case, not only must he have made these nineteen statues in twenty years, but some fifteen more at least. Taking, then, the longest supposition as to his age, and giving him forty-five years of labor for some thirty-five statues, the time will altogether be too restricted. It may be as well at this point of the discussion to give a catalogue of the works which he is supposed to have executed, and to examine into the probable authenticity of some of them. The list is as follows:—