As he had not failed to observe, earlier in the day, the book-lined walls of the library were broken, opposite the window, by a panelled alcove where a small table stood, beyond which, against the wall, was a very large and tall grandfather's clock of black and gold lacquer, in imitation of the Chinese designs so popular in the eighteenth century.
Among Lord Ashiel's last words, "The clock" had been uttered immediately after the detective's own name. No doubt they formed part of a message he wished to convey; and, though they might refer to any clock in or out of the house, it seemed to Gimblet worth while to begin his investigations with the one nearest at hand, and he turned his attention to it without loss of time.
Gimblet was a connoisseur of the antique, and a few minutes' examination proved to him that this was a genuine old clock, untouched by the restorer's hand, and in an excellent state of preservation. The works appeared all right as far as he could make out, but through the narrow half-moon of glass, so often inserted in the cases of old clocks for the purpose of displaying the pendulum, that article was not to be seen, and he found that it was missing from inside the case, as were also the weights, so that it was impossible to set it going. There was one odd thing about it, which the detective had already remarked: it was firmly fixed to the wall by large screws, and he thought that there must be some opening through the back into a receptacle contrived in the panelling behind it. The case was so large that he was able to get inside it, and examine inch by inch the wood of the interior, which was lacquered a plain black.
But his most careful tappings and testings could discover no hidden spring, nor, even by the help of the electric torch--which he passed all over the smooth surfaces of the walls--could he discern the slightest join or crack. Could there be a hiding place up among the wheels of the motionless works? His utmost endeavours could discover none. The clock was fully eight feet high, but with the help of a stool, which he put inside on the floor of the case, he was able to explore even the topmost corners. All to no purpose.
Presently he abandoned that field of research, replaced the stool whence he had taken it, and gave his attention to the surrounding walls. He examined each panel with the most painstaking care, but could find nothing. There was no sign of secret drawer or cupboard anywhere.