He knew how to look for them, where to search for them, and much of the principle upon which they were constructed, just as one may have studied and learned to know the moves in a game of chess.
To offer an opportunity for a secret entrance and passage, there must be space—space between two walls.
And so, when Nick Carter started across the room exclaiming to Patsy: “Found it there, did you? Show me just where you found it,� he did not wait for the answer, but hastened at once to one of the windows, stepped upon the sill and, leaning far out of it, studied the general construction of that north wall of the main building.
A mere glance sufficed him.
He knew already that that part of the house was very old; had stood there where it was through several generations until it had been remodeled, enlarged, reconstructed, and embellished into a part and parcel of the great mansion.
That mere glance outside the window satisfied him that there was more than sufficient space between the outer wall and the wall of the room inside for a passageway.
And that was practically all he needed to assure himself that he had discovered the most likely place for a secret passage and entrance to that room, if one existed.
Moreover, what more likely place could be found for such a secret entrance as must exist than the life-size portrait itself and the space—that is, breadth—behind it?
He stepped back into the room again.
As he did so, and before he could begin his search for the secret entrance, Thomas returned from his hasty inventory of Lynne’s wearing apparel.