306 Pneumatic Transmission. [July, 



Great Certainty and Rapidity by Air," in which may be re- 

 cognised the first practical suggestions for the introduction 

 of what is now known as the "Pneumatic System ;" and it 

 is not a little surprising to find that in this, and two subse- 

 quent pamphlets by the same author, are foreshadowed 

 almost everything that has hitherto been discovered .in 

 connection with this subject — all subsequent inventions 

 having reference merely to the detailed means for carrying 

 that system into effect. 



George Medhurst's first idea clearly was to employ the 

 pneumatic system for the conveyance of small parcels only, 

 but he subsequently suggested its application for the trans- 

 port of goods of a more bulky nature. It is perhaps a pity 

 that he did not confine his attention in the first instance to 

 the development of his earliest ideas on the subject, and 

 which has subsequently been proved to be the most practical 

 method of applying his inventions, viz., for the transmission 

 of letters and small parcels. The rage of the day being, 

 however, for improved means of communication, it is not 

 surprising that his own ambition and the popular clamour 

 should have caused Medhurst to endeavour to apply his inven- 

 tion to a purpose for which it was ill-suited. We shall not 

 now follow the progress of the gradual rise and fall of the 

 atmospheric railway, from the time when John Vallance, in 

 the year 1826, constructed a model tunnel in Devonshire 

 Place, Brighton, 120 feet long, and nearly 8 feet in dia- 

 meter, through which a carriage was propelled by means of 

 air pumps worked by two steam engines, which was the first 

 of its kind ever constructed, to the abandonment of the 

 atmospheric principle upon the Paris and St. Germains line 

 for the last mile and a-half of its length, which was taken up 

 in the year i860, after having been in successful operation 

 for about 15 years. From this last-named circumstance it is 

 clear that the atmospheric system is not wholly unsuited for 

 railways under certain circumstances, the chief ground of 

 its applicability being upon very steep inclines, such as were 

 unsuited for locomotives. The inconvenience, however, of 

 having different systems of propulsion upon the same railway 

 has been the cause which has led to the abandonment of the 

 atmospheric principle upon every railway where it has ever 

 been tried ; the general advantages, greater speed, and un- 

 doubted superiority of the locomotive gaining for it, in every 

 case, the preference over the latter. 



Thus ended all attempts to introduce atmospheric rail- 

 ways ; but a few years before their final abandonment the 

 adaptation of the principle for the transmission of small 



