112 

 CHAPTER VII.* 



ON SOUND. 



SOUND. BELL IN EXHAUSTED RECEIVER. SILENCE IN ELEVATED 



PARTS OP GLOBE. PISTOL ON MONT BLANC. METEORS. DIFFER- 

 ENT VELOCITY OF SOUND IN DIFFERENT BODIKS. EXPERIMENT 



OF THE CRACKED GLASS AND CHAMPAGNE- SOUNDS AT NIGHT. 

 ILLUSTRATION OF THE MIRAGE. ICE A CONDUCTOR OF SOUND. 

 SEA FIGHTS. SPEAKING PIPES. WELL AT CARISBROOK. CAST- 

 IRON PIPES AT PARIS. NEW BELL. ECHO AT GIRGENTI. SOUND 



CONVEYED BY WATER. ALONG WOOD, WIRE, ETC. VENTRILO- 

 QUISM. SENSIBILITY OF THE HUMAN EAR. EAR OF DIONYSIUS. 



STATUE OF MEMNON. MUSICAL ROCKS. SCIENTIFIC KNOWLEDGE 

 OF THE ANCIENT PRIESTS. 



HENRIETTA. 



AUNT, I have been calling to Mary these last ten minutes, 

 to tell her to come in, as it rains, but she will not answer 

 me. 



MRS. F. 



Are you quite sure that she hears yoil 1 ? 



HENRIETTA. 



Perfectly so; for the other morning she heard me very well 

 though she was much farther down the garden. 



MRS. F. 

 But perhaps it did not rain then. 



HENRIETTA. 



No, it did not; but what difference would that make? 



* The first part of this chapter is chiefly taken from the review of 

 Herschel's Treatise, in vol. xliv. of the Quarterly Review. 



