Note 89 — CHRONOLOGY OF UNIVERSAL HISTORY
Reading edition
A specimen of an early speaking-tube exists, connecting the room said to have been occupied by Isabella with the old brewhouse, now a tavern, by means of which Mortimer was wont to communicate with his mistress. The castle stands upon a mount of 280 feet, sheer rock, and the brewhouse is at its base. A peculiarity of the tube, bored through the live rock, is an elbow-joint, which is a puzzle to scientists.