"Not that I know of."
"Then your objection falls to the ground. If you could have told me that one had tried to find the place, but without success, I would have admitted some force in it, though it would not have satisfied me without knowing the plans he had taken, and how they were carried out. On the other hand it may have been known to many who held their peace about it.--Would you not like to know the truth concerning that too?"
"I should indeed. But would not you be sorry to lose another mystery?"
"On the contrary, there is only the rumour of a mystery now, and we do not quite believe it. We are not at liberty, in the name of good sense, to believe it yet. But if we find the room, or the space even where it may be, we shall probably find also a mystery--something never in this world to be accounted for, but suggesting a hundred unsatisfactory explanations. But, pardon me, I do not in the least presume to press it."
Lady Arctura smiled.
"You may do what you please," she said. "If I seemed for a moment to hesitate, it was only that I wondered what my uncle would say to it.
I should not like to vex him."
"Certainly not; but would he not be pleased?"
"I will speak to him, and find out. He hates what he calls superstition, and I fancy has curiosity enough not to object to a search. I do not think he would consent to pulling down, but short of that, I don't think he will mind. I should not wonder if he even joined in the search."
Donal thought with himself it was strange then he had never undertaken one. Something told him the earl would not like the proposal.
"But tell me, Mr. Grant--how would you set about it?" said Arctura, as they went towards the tower.
"If the question were merely whether or not there was such a room, and not the finding of it,--"
"Excuse me--but how could you tell whether there was or was not such a room except by searching for it?"
"By determining whether there was or was not some space in the castle unaccounted for."
"I do not see."
"Would you mind coming to my room? It will be a lesson for Davie too!"
She assented, and Donal gave them a lesson in cubic measure and content. He showed them how to reckon the space that must lie within given boundaries: if then within those boundaries they could not find so much, part of it must he hidden. If they measured the walls of the castle, allowing of course for their thickness and every irregularity, and from that calculated the space they must hold; then measured all the rooms and open places within the walls, allowing for all partitions; and having again calculated, found the space fall short of what they had from the outside measurements to expect; they must conclude either that they had measured or calculated wrong, or that there was space in the castle to which they had no access.
"But," continued Donal, when they had in a degree mastered the idea, "if the thing was, to discover the room itself, I should set about it in a different way; I should not care about the measuring. I would begin and go all over the castle, first getting the outside shape right in my head, and then fitting everything inside it into that shape of it in my brain. If I came to a part I could not so fit at once, I would examine that according to the rules I have given you, take exact measurements of the angles and sides of the different rooms and passages, and find whether these enclosed more space than I could at once discover inside them.--But I need not follow the process farther: pulling down might be the next thing, and we must not talk of that!"
"But the thing is worth doing, is it not, even if we do not go so far as to pull down?"
"I think so."
"And I think my uncle will not object.--Say nothing about it though, Davie, till we give you leave."
That we was pleasant in Donal's ears.
