text:  It is impossible to read the admirable account of Hannibal's campaign in the last volume of Arnold's _History of Rome_ without perceiving that this observation as to the decisive effect of the Numidian cavalry upon the fortunes of the war in first giving victory to the Carthaginians when they were entirely on their side and gradually and at length decisively restoring it to that of the Romans when they were won over to their eagles is entirely well-founded