66 



NA JURE 



{Nov. 27, 1873 



the worst accident they have to fear is the bursting of the 

 tube. To this drawback, which happens very rarely, we 

 shall refer by-and-by. 



The messages are divided into two classes, — questions 



and answers, orders and the execution of orders, which 

 can at once be exchanged between any point of the city 

 and any point of the interior, in the provinces, or abroad, 

 — or inversely. All that is necessary in this case is a 



Fig. I. — Apparatus for the production of compressed r 



centre, as the Hotel des Tdldgraphes in the Rue de 

 Crenelle is called. Connected in the one part with 

 the exterior by the network of electric wires, and 



with the interior by the network of pneumatic Subex 



These tubes are, moreover, well adapted for the secvice 



of the local post, i.e. for the exchange of messages withia 



the city. The great advantage in this case is that the than an hour. Every year the development of the lines= 



despatch can be sent. On the plan adopted, when the increases, and the number of Paris telegframs meant for 



network is complete, a letter may always be sent from one the city, and of which the originals themselves can be 



quarter to another at any distance within Paris in less transmitted, is getting greater and greater. 



