This he had expected would be the case, and after the dinner interval he began what he knew would be one of the most tedious parts of the undertaking. It was necessary that he should scrape away part of the stone in order to get his fingers under. His pocket-knife was evidently a better tool for this than the dinner knife he had hitherto used. The slab, so far as he could make out, was a sandstone, but how hard he could not tell. He began by dipping his handkerchief into his basin and letting fall a few drops at the place upon which he intended to operate, namely, next his bed. He started very carefully, giving a sort of rotatory motion to his knife. Gradually the water he had dropped there became a little turbid; this afforded him some encouragement, and he worked steadily on till evening, by which time he had succeeded in removing a piece of the stone an eighth of an inch deep.
After supper he began again, and continued the work far into the night, for he was always furnished with a lamp. At last he had increased the hole to a depth of fully a quarter of an inch, and a width equal to that of his four fingers. Well satisfied with this result, he threw himself on his pallet and slept soundly until the flap was opened and his breakfast tray thrust in. As soon as he had finished his breakfast he set to work again, this time using the knife that had been handed in with his breakfast, and which would not be demanded of him until he returned the tray when he received his dinner. He was glad to make the change, for his hands were blistered badly by the previous day's work, and the smoothness of the dinner knife was a relief to him; besides, he saw that he had already worn away the point of his pocket-knife.
After a fortnight's steady work he had the satisfaction of feeling the knife go through. In two more days he was able to get his hand in. He now cleared out some of the earth at the bottom, and then, putting his hand below the stone, exerted his strength to the utmost, and was delighted to find that it yielded. He laid it down and executed a dance of triumph, which would have astonished the monks had they looked in.
CHAPTER XVIII
ESCAPED
It was evening when Arthur got up the stone, so he put it into its place again after his delight had a little subsided, rubbed some dust into the crevices, and then flung himself down for a long night's sleep. The next morning after breakfast he set to work to remove the dust round the next stone. When he had done this, he made a hole under it with his fingers even more easily than in the case of the first. He then replaced it, and waited until his dinner had been handed in. Having eaten this, he took up the two stones again, laid one upright against the wall under the window, placed the other on the top of it, then took a running jump on to this, at the same moment stretching his arm as high up above his head as he could. To his delight he found that he was able to grasp one of the bars. He got down, took one of the blankets, and, again leaping up, passed an end round the bar and managed to grasp it before he fell backwards.
This pulled the blanket half-way round the bar. He caught hold of both parts when he next sprang up, and was able without difficulty to raise himself until his face was level with the window. The look-out was better than he had expected. In front of him was a street, but on the other side was a piece of waste ground. Nothing could have been handier for his purpose, as the stones and earth thrown on to this would certainly attract no notice. Having taken a good look he lowered himself to the floor, relaid the second stone he had raised, and put the other alongside it so that he could replace it in an instant if he should hear footsteps coming down the passage. Then he took the mattress and bedding off the bench, for he resolved to spread upon the bed all the earth and rubble he got out during the day, as it would be dangerous to throw it out until dark.
After this he set to work with the dinner knife, and it was not long before he had loosened the earth and rubble some inches deep. This he removed, and by night had excavated a hole two feet deep, spreading the rubbish carefully, as he got it out, on the bed. He had not made the hole quite so wide as the stone, in order that this might have a support when it was replaced. Then he hung up one blanket as before, and placed a considerable quantity of the earth in the other blanket and hauled this up to the window, so as to save himself the labour of climbing up afresh with each handful. Listening attentively, so as to be sure that no one was coming along, he flung it with all his force through the window. When he had disposed of all he had brought up he filled the blanket again, and so continued until he had thrown out the whole.
On the following day he not only got out the earth to a greater depth, but was able to push the trench under the adjoining slab, which was in contact with the wall. He got rid of the earth and stones as before. Next morning he worked with renewed vigour, for the result of the day's labour would be to show whether the stone-work was carried down below the level of the floor, or whether the wall rested upon concrete. The third slab came up without difficulty, and, digging down by the wall, to his great satisfaction he found that it rested on a foundation of coarse concrete, which would no doubt be troublesome, but by no means impervious. He soon cleared out the earth and rubble to the same level as the other part of the trench, and after spreading it as usual under his mattress, he began the important task of picking out the concrete. He had not been at work long before he found that in order to get room to use both arms he must widen it out at the end against the wall. This caused a whole day's delay. The cutting of the concrete was toilsome, and it took a week of almost incessant labour to make a passage sufficiently large for him to crawl through. Having ascertained that, as he had expected, the ground beyond this was composed of mixed soil, as that within the wall had been, with fragments of stone, he gave himself a day's rest before proceeding further. It was now six weeks since his imprisonment began, and he felt sure that it would require only three or four days' more work to get to the surface outside.
He wondered what his friends had been doing, and worried greatly about the anxiety that Mercedes would have experienced. This thought indeed had frequently kept him to his work when he would otherwise have desisted, from the fatigue he felt in working in the cramped position which was necessary while getting through the concrete. Roper, too, would be in a terrible way, and Leon would be moving heaven and earth to find some clue to his fate. He wondered what they had been doing, and in what direction they had been searching, for he would have disappeared as suddenly as if the earth had opened and swallowed him, without leaving a single clue.