The attack of Savoy, whose sovereign, the King of Sardinia, was brother-in-law of the Comte d'Artois, and had naturally been active in the cause of the Bourbons, was successfully commenced, and carried on by General Montesquiou already mentioned, a French noble, and an aristocrat of course by birth, and as it was believed by principle, but to whom, nevertheless, the want of experienced leaders had compelled the ruling party at Paris to commit the command of an army. He served them well, possessed himself of Nice and Chamberi, and threatened even Italy.[300] On the centre of the same line of frontier, Custine, an excellent soldier and a fierce republican, took Spires, Oppenheim, Worms, finally the strong city of Mentz, and spread dismay through that portion of the Germanic empire. Adopting the republican language of the day, he thundered forth personal vengeance, denounced in the most broad and insulting terms, against such princes of the Germanic body as had distinguished themselves by zeal against the Revolution; and, what was equally formidable, he preached to their subjects the flattering and exciting doctrines of the Republicans, and invited them to join in the sacred league of the oppressed people against princes and magistrates, who had so long held over them a usurped power.[301] But the successes of Dumouriez were of a more decided and more grateful character to the ruling men in the Convention. He had a heavier task than either Custine or Montesquiou; but his lively and fertile imagination had already devised modes of conquest with the imperfect means he possessed. The difference between commanders is the same as between mechanics. A workman of commonplace talents, however expert custom and habit may have made him in the use of his ordinary tools, is at a loss when deprived of those which he is accustomed to work with. The man of invention and genius finds out resources, and contrives to make such implements as the moment supplies answer his purpose, as well, and perhaps better, than a regular chest of working utensils. The ideas of the ordinary man are like a deep-rutted road, through which his imagination moves slowly, and without departing from the track; those of the man of genius are like an avenue, clear, open, and smooth, on which he may traverse as occasion requires. Dumouriez was a man of genius, resource, and invention. Clairfait, who was opposed to him, a brave and excellent soldier, but who had no idea of strategie or tactics, save those current during the Seven Years' War. The former knew so well how to employ the fire and eagerness of his Carmagnoles, of whose blood he was by no means chary, and how to prevent the consequences of their want of discipline, by reserves of his most steady and experienced troops, that he gave Clairfait a signal defeat at Jemappes, on the 6th November, 1792.[302]