56 ANNUAL OF SCIENTIFIC DISCOVERT. 



the; present avrano-omcnts. . . . There is no diiricniltf in so ap- 

 plyiiii;" and securing; tliat middle-rail, and niakiii<^ it virtually one 

 continuous bar, as to iM'eclude the possibility of accident from its 

 Aveakness or from the failure of its fastenings; and the only ques- 

 tion to my mind is whether it would not be desirable still further 

 to extend its application to gradients less steep than one in twenty- 

 four, with a view to greater security, especially on curved portions 

 of the line." Similar favorable reports were quoted from the 

 French Imperial Commissioner, while it was stated that those of 

 the Italian, Russian, and Austrian Commissioners were e<iually 

 favorable and conclusive. In November and December last, the 

 Frenc-li and Italian Governments granted concessions, authorizing 

 the railway on the Imperial postal road ov(;r the JNIont Cenis with 

 a width of about thirteen English feet; and a company has since 

 been formed to carry out the undertaking. The works were com- 

 menced in March, and the line is cxiiected to open in May next. 



Attention was directed at some length to the conditions essen- 

 tial to the success of the system, the lirst of Avhich was the em- 

 ployment of different ty^ies of engines, according to the heaviness 

 of the gradients ; of each of which full descriptions were given, 

 with the aid of colored diagrams. The carriages, as well as the 

 engines, are each furnished with four horizontal wheels, wliich 

 have flanges underlapjiing the centre-rail. These act both as 

 guide and safety wheels, i)reveutiug the carriages from leaving 

 the rails, and, hx guiding them round the curves, greatly dimin- 

 ish the irictional resistance and the tractive power required, 

 thereby rendering it easy to reduce the weight of the engine to 

 that which was necessary for producing and carrying the power 

 required for the traction of the train. The economy of weight 

 has been effected by a simpler arrangementof the machinery, and 

 by using an improved quality of material. For the making of 

 mountain lines, which ai"e exposed at certain seasons to an unfa- 

 A'oraljle climate, from the effects of snow, frost, and fogs, it was 

 desirable to devise some means of cleaning the surface of the rails, 

 and for improving the state of adhesion as the trains advanced, so 

 as to dispense with the use of sand. This might be done at speeds 

 from five to ten miles an hour ; ice and snow might be cleared off 

 by cutters attached to the engine; and, in seasons of mist, ne.w 

 machinery could be probaljly contrived for removing that almost 

 imperceptible film of mist which diminishes the adhesion to nearly 

 the same extent as ice. The adhesion was best in the winter, 

 when the snow remained for months in a state of dry powder ; but 

 the places where it accumulated were protected by covered ways, 

 and the rails were always in good condition. 



He said that the centre-railway system was never intended to 

 be worked on any except the steepest inclines, where no other 

 engines could work. It would be only necessary to have a cov- 

 ered way for fourteen kilometres, which would cost £40,000. One 

 kilometre in the avalanche district, which was well known, would 

 have to be pi'otected by stone ; but the remainder would he pro- 

 tected by wood, which was amply strong enough to resist the weight 

 of from twenty to thirty feet of accumulated snow. — Reader, 1866. 



