14G farmers' and mechanics' journal. 



ing intelligence, which occurred to us years ago, when we used t© 

 amuse ourselves by whispering to our schoolnmates, through the 

 long wooden tubes, in a Pump-maker-s yard. It then appeared 

 possible to convey distinct words to a great distance through tubes 

 of wood or metal, laid in the ground like an aqueduct* No chance 

 ever occurred for trying the experiment. We once proposed it to 

 gi person who was repairing an aqueduct, but was heartily laughed 

 at for a silly boy, and thus it ended. We are pleased to find, how- 

 ever, that the scheme is not altogether so visionary and puerile as 

 it at first seems to be. A Mr. Dick, of England, has tried some 

 experiments upon this subject, and found that the human voice 

 might be made intelligible twenty-five or thirty miles. The Revue 

 Encyclopedique, on the strength of those experiments, recommends 

 the manner to be put into general practice. Father Kircher re- 

 lates in some of his works, that the laborers employed in the sub- 

 terranean aqueducts of Rome, heard each other at the distance of 

 several miles. 



Some interesting experiments of Biot, on the transmission of 

 sound through a metallic tube, in some degree prove the feasibility 

 of the plan. It was tried in order to ascertain the comparative 

 capacity of air and solid bodies in transmitting sound. 



" At the extremity of a cylindrical tube, upwards of 3000 (eet in 

 length, (over a half of a mile,) a ring of metal was placed of the 

 same diameter as the aperture of the tube ; and in the centre of 

 this ring, in the mouth of the tube, was suspended a clock bell, and 

 hammer. The hammer was made to strike the ring and the bell 

 at the same instant, so that the sound of the ring would be trans- 

 mitted to the remote end of the tube through the conducting power 

 of the matter of the tube itself, while the sound of the bell would 

 be conducted through the medium of the air enclosed within the 

 tube. The air being transmitted by the metal of the tube, was 

 first distinctly, and after a short interval had elapsed, the sound of 

 the bell transmitted by the air in the tube, was heard. The result 

 of several experiments was, that the metal of the tube conducted 

 the sound with about ten and a half times the velocity with which 

 it was conducted by the air ; viz. 1 1,865 feet per second, and that 

 the air conducted it 1142 feet in a second." 



To put this project into practical operation, why could not tubes 

 be placed under ground, out of harm's way, continuing any re- 

 quired distance, and opening into a small tight room ? In this 

 room should be placed some of those anxious mortals, who delight 

 to listen to, and tell the news first — if they can. This person 

 could hear what was said to him from the other extremity of the 

 tube, and if another tube commenced at the other side of the room.. 



