482 Mechanism and its Marvels. MAY, 



the contrivance, which has now become so common in the shops of 

 workmen and tradesmen, the tin tube by which a message is conveyed 

 through all parts of the house, at the moment, and which of course 

 saves the delay and trouble of sending a servant. Those tubes are 

 capable of a much more general application, and might be very con- 

 veniently applied to every house. The principle is now to be tried on 

 a larger scale. It is proposed, by means of a small tube throughout the 

 length of the Liverpool and Manchester railway, to convey information 

 as quickly as in conversation. The length of the longest tunnel of the 

 Liverpool and Manchester railway is about 6,600 feet, but it is thought 

 that articulate sounds could be transmitted not only through the tun- 

 nels, but along the whole length of the railway. Its convenience on 

 the railway would be obvious, as by a few men stationed at regular dis- 

 tances, even miles apart, warning could be instantly given through the 

 speaking-pipe of any obstruction or accident. But the probability is, 

 that it will be discovered that not only can the words of a speaker at 

 Liverpool be transmitted to Manchester, but that they can be transmitted 

 through any distance however great, and with an almost instantaneous 

 rapidity. The progress of sound through the air is well known to be 

 1142 feet in a second, and it is a singular fact that the feeblest sound 

 travels as rapidly as the loudest : thus a whisper has the speed of a burst 

 of thunder. But by all the experiments on tubes, it appears that the 

 transmission of sound is infinitely more rapid than in the open air, or 

 actually occupies no time whatever. 



A series of experiments made a few years by M. Biot and other 

 French mathematicians when the iron pipes were laying down for con- 

 veying water to Paris, seems to promise an unbounded power of trans- 

 mission. They joined long ranges of those pipes to each other, so as to 

 make a continued tube of several miles. The results were, that the 

 lowest whisper at one end of the tube was heard with the most perfect 

 distinctness at the other, and that it was heard instantaneously. The 

 moment the speaker at one end was seen to apply his lips to the tube, his 

 words were heard at the other. If this discovery should be substan- 

 tiated by the railway tube, man will possess another power over nature 

 of the most curious and the most useful kind. The telegraph, admira- 

 ble an invention as it is, would be a toy to an instrument by which a 

 public order or any other piece of intelligence could be conveyed at its 

 full length from the seat of government to a seaport, or any other im- 

 portant spot of the kingdom, equally in fog and clear weather, night 

 and day, and without even the delay that occurs by the telegraph. The 

 sailing and triumph of a fleet, the surprise of an enemy, a stroke that 

 might decide the fate of a nation, might be the consequence of this 

 simple invention. And its value would be still enhanced, if in the 

 course of time, it could be turned to the individual use of the com- 

 munity ; if a system could be established allowing every body to avail 

 himself of this mode of communication ; like the Post Office, the in- 

 tercourse of which was originally established only for the usues of the state 

 and monarchs, but is now turned to the service of every man who de- 

 sires to write a letter. 



With this project, however, we by no means rank the following : 



" Atmospheric Letter Carrying. A curious model of a tunnel, through which 

 the mail-bags might be projected, is now exhibiting- in Glasgow, by a Mr. 

 Read. According to a calculation by Professor Stevelley, of Belfast, twelve 



