The queen observed that, even without her interposition, Mary was sufficiently depressed by the mutinous spirit of her own subjects; and instead of giving Scotland for the present any inquietude or disturbance, she employed herself, more usefully and laudably, in regulating the affairs of her own kingdom, and promoting the happiness of her people. She made some progress in paying those great debts which lay upon the crown; she regulated the coin, which had been much debased by her predecessors; she furnished her arsenals with great quantities of arms from Germany and other places; engaged her nobility and gentry to imitate her example in this particular; introduced into the kingdom the art of making gunpowder and brass cannon; fortified her frontiers on the side of Scotland; made frequent reviews of the militia; encouraged agriculture, by allowing a free exportation of corn; promoted trade and navigation; and so much increased the shipping of her kingdom, both by building vessels of force herself, and suggesting like undertakings to the merchants, that she was justly styled the restorer of naval glory, and the queen of the northern seas.[*] The natural frugality of her temper, so far from incapacitating her for these great enterprises, only enabled her to execute them with greater certainty and success; and all the world, saw in her conduct the happy effects of a vigorous perseverance in judicious and well-concerted projects. * Camden, p. 388. Strype, vol. i. p. 230, 336, 337. It is easy to imagine that so great a princess, who enjoyed such singular felicity and renown, would receive proposals of marriage from every one that had any likelihood of succeeding; and though she had made some public declarations in favor of a single life, few believed that she would persevere forever in that resolution. The archduke Charles, second son of the emperor,[*] as well as Casimir, son of the elector palatine, made applications to her; and as this latter prince professed the reformed religion, he thought himself, on that account, better entitled to succeed in his addresses. Eric, king of Sweden, and Adolph, duke of Holstein, were encouraged by the same views to become suitors: and the earl of Arran, heir to the crown of Scotland, was, by the states of that kingdom, recommended to her as a suitable marriage. * Haynes, vol. i. p. 233.