Next morning after breakfast was over Dick produced a pile of towels, which we divided up between us for our voyage of discovery. 'After all,' I said, 'we shan't want many, for bows and arrows in the far past, and later, the window tax, kept the number of openings down.'
We ascended by the ancient stone newel stair that circled up from the old iron 'yett' of the entry to the battlements above, and laid a towel below the sash of every window. In the topmost storey in some servants' rooms that had been long disused we discovered certain windows with broken cords that entirely refused to open.
Dick's way here was of the 'Jethart' kind. He simply knocked a pane out with the poker, and thrust the towel through.
When we had finished we descended in haste and perambulated the tower without, counting up our tale of towels in some excitement.
'As many windows, so many towels,' I said with disappointment, as I checked them off carefully.
'Damn!' said Dick meditatively. Then after a moment or two's thought, 'The old boy's cell must have been on the roof; he was sure to have been an astrologer. Let's go up again and start afresh.' So saying he led the way up to the parapet of the battlements, and there we surveyed the roof. The main part of the roof consisted of a gable covered with heavy stone tiles, but the further part that lay between the north-east and north-west bartizans was flat and covered with lead, and at the verge of this were iron steps that led down to the roof of the new wing below. This latter we did not concern ourselves with, as we knew it dated since the wizard's day, but carefully examined the stone tiles and the further leads without, however, any discovery resulting.
We were just about to give up our quest when Dick's quick eyes noticed a chink in the lead that formed the channel or gutter for the rain water leading either way to the gargoyles beneath the bartizans outside.
'Look here!' he cried. 'See the dim light showing! I swear it's a glimmer of glass. Evidently this particular lead was meant to be drawn aside and admit the light.' I hastened to the side and peered with him into the dirt-laden crack.
Opening my pen-knife I scraped away the dirt and soon verified his conjecture that there was glass below. 'You're right!' I cried in my excitement. 'It is glass. Now let's search and see if we can find anything like a hinge, or at least some indication that the lead could be withdrawn at will.' We sought all along by the containing wall and found that the lead did not end in a flat sheet, as is usual, against the wall, but was turned over, and evidently continued below.
'It looks very much as if it was meant to roll up and be turned over like a blind on a roller below,' I said to my companion.