1871.] Pneumatic Transmission. 305 



tion of the process. The position of the parties is, indeed, 

 very clearly explained at the commencement thus: — 



"Art. 1. A partnership will be established between MM. 

 Niepce and Daguerre for the purpose of working out the 

 said discovery invented by M. Niepce, and improved by 

 M. Daguerre." 



We all know how Niepce died a few years after this 

 agreement was made, while the world was yet unacquainted 

 with the works he had so patiently and modestly accomplished, 

 and how Daguerre in 1839 communicated to the Paris 

 Academy the wonderful process of Daguerreotype, a method 

 which, while dissimilar and superior to that of Niepce, was 

 nevertheless due in some measure to that philosopher's 

 discoveries. All honour and fame to Daguerre for making 

 one mighty stride of progress in the beautiful art of 

 photography, but we should doubtless have admired him 

 more if, when publishing his invention to the world, instead 

 of ignoring Niepce's early aid, he had generously made some 

 mention of the labours of his dead partner. 



II. PNEUMATIC TRANSMISSION, 

 By Frederic Charles Danvers, A.I.C.E. 



f W^HE practical application of air to the transmission of 



carriages on land dates only from the commencement 

 of the present century. The first idea, however, of 

 transmitting power to a distance by means of pneumatic 

 pressure appears to have originated with the celebrated 

 Denys Papin, a Frenchman, who, in 1688, described an ap- 

 paratus in which a partial vacuum produced in a long tube, 

 by air pumps fixed at one end, caused the motion of pistons 

 at the other end ; but no record remains to prove that any 

 steps were taken by Papin to carry his suggestions into 

 effect so as to derive any useful practical advantage from 

 them. The introduction of the locomotive engine naturally 

 directed the attention of engineers and others to the subject 

 of the provision of improved means of communication, and 

 this desire was doubtless stimulated by the acknowledged 

 defects of the locomotive at that time, and its reputed inap- 

 plicability for lines with gradients exceeding 1 in 100. The 

 first person to introduce the atmospheric system of propul- 

 sion was a mechanical engineer named George Medhurst, 

 who, in 1810, published a pamphlet on the subject entitled 

 " A New Method of Conveying Letters and Goods with 



VOL. VIII. (O.S.) — VOL. I. (N.S.) 2 R 



