would be required. Often, as at Gumfreston, the church was the only building strong enough to give adequate security to human beings and to portable property. Castles do not exist everywhere, neither, indeed, do these sturdy towers; but the one group seems to be largely complementary to the other. Exception has also been taken to the evidential value of the narrow window openings. Mr Allcroft, while expressing agreement with the theory that ecclesiastical towers were frequently employed for protection, deprecates an appeal to these narrow slits as affording satisfactory testimony[293]. He contends that the openings were made strait and were provided with an inner splay to minimize draughts. That they would be moderately efficient for this purpose may be conceded. Not only the ordinary current of air, but the high gale, had to be foreseen and provided against. Glazing the apertures was out of the question, in the early times when glass was a costly article, especially in remote counties. But there is another mode of approaching the question. What was the purpose of the well-known “oillets” in buildings purely defensive? Even in primitive warfare no tower was impregnable if it presented wide openings to the foe. Arrows and slingstones would, under certain conditions, prove more swift and deadly agents than fire itself. We may grant that the round-headed twin aperture, with its single plain baluster-shaft in the middle, so familiar in the late Saxon towers of England, was not avowedly of a defensive character. That admission does not exclude a belief in the defensive value of the narrow window. During the Perpendicular period a tiny battlemented parapet was frequently used for the ornamentation of a capital or transom, but such a practice does not negative the original use of the battlement in fortification. Further it might be reasonably argued that the strait window-opening was copied from secular strongholds because it originally served one purpose in all cases. The point is not of prime importance, but it is worthy of note that the narrow loophole continued to prevail after glass had come into general use for church windows, and after bells had become common. The price of glass was, therefore, not the deterrent. Again, the bell-ringer would perhaps have actually welcomed a wider opening. Whatever may have been the motive, we find that, from the Early English period onward, the tiers of spire lights known as dormer window’s or lucarnes, though mainly decorative in character, continued to be made very narrow. On the other hand, these dormers were so arranged that one series was placed, with respect to the group above or below, on alternate sides of the spire. One fact remains; in towers which were designed to withstand attack, the retention, if not the initiation, of the narrow type of opening, suggests motives of strategy.