His general idea was to out the Highlands asunder along the line of what is now the Caledonian Canal, and to fix his enemy within one of two definite areas, where he could operate against him as he chose. The area to the north of the line was sufficiently determined by its geographical conformation, but that to the south had to be firmly marked by strategical positions. Already a chain of fortresses and strong posts stretching from Inverness through Stirling to Ayr shut it in on the south and east, and during the next two months, while Monk was waiting for the grass to grow sufficiently for him to be able to move his cavalry, the investment was completed. On the west, from Glencoe to the head of Loch Lomond, diplomacy secured Argyle's country in a state of armed neutrality, and at each of the four salient angles of the area was established an independent base. One was at Inverness, one at Perth, and a third at Kilsyth, between Stirling and Glasgow, with Leith for its supporting base. The fourth by a bold stroke was to be planted in the heart of the enemy's country at Lochaber, with supporting bases at Liverpool and Ayr, whereby he would complete his quadrilateral and secure the southern end of his dividing line. From these points he intended to act on double lines of operation, with two strong columns keeping light touch with one another, and each able at any moment to act in a new direction by a rapid change of base. One of them he was to lead himself, while Morgan took command of the other. Their organisation was a source of the greatest care. As he was not likely to meet horse in any numbers, Monk boldly eliminated from the foot nearly the whole of the pikes on which the steadiness of infantry was supposed to depend, and filled his ranks almost entirely with musketeers. To the labour of laying this elaborate foundation for the campaign was added the task of reducing the army to some sense of discipline. Monk had found it badly demoralised by the incapacity of Lilburne, and the license which he had allowed to religious controversy. On all this he set his foot, and at the same time endeavoured to repair the mischief which the wanton insolence of the sectaries had done, by inaugurating a conciliatory policy towards the Scots--a policy, however, which he was careful to fortify by a system of strong patrols in the Lowlands.