\"Yes。\"
\"Well，makeready，Iamabouttopronounceyourname，\"saidtheProfessor。
Iappliedmyearclosetothesidesofthecavernousgallery，andassoonastheword\"Harry\"reachedmyear，Iturnedroundand，placingmylipstothewall，repeatedthesound。
\"Fortyseconds，\"saidmyuncle。\"Therehaselapsedfortysecondsbetweenthetwowords。Thesound，therefore，takestwentysecondstoascend。Now，allowingathousandandtwentyfeetforeverysecond-
wehavetwentythousandfourhundredfeet-aleagueandahalfandone-eighth。\"