The experience of the atmospheric system on the Dalkey line has called forth the most opposite opinions on its merits from engineers and other scientific characters; some asserting that the superiority of the atmospheric over the locomotive system is clearly established by the results obtained, whilst others maintain that these results prove not merely that it is inferior to the locomotive system, but that it is utterly inapplicable in the generality of situations and circumstances in which railways are called for. Amongst those who have formed a favourable opinion of the scheme, we may mention Mr. Vignoles, the engineer to the Dublin and Kingstown railway, at whose recommendation the trial of the system on the Dalkey line was made, and who has since decided upon adopting it on a line from Vienna to Schonbrunn. This line, however, is to be a double line, thereby obviating some of the objections raised against the system on the score of the difficulty of working the lines with regularity and punctuality - but at the same time annulling most of the advantages claimed for the system in point of economy of construction and of working.

Mr. Brunei has not only expressed a decidedly favourable opinion of the system, but has adopted it on a line now constructing by him (the South Devon, if we recollect rightly). Mr. Cubitt, although expressing a more qualified opinion, has deemed the plan worthy of trial on a portion of the Croydon line, in contemplation of its farther application on the line from Croydon to Epsom; and an atmospheric line is in progress from the latter place to Portsmouth, The French Government (in consequence we believe of M. Mallet's report) have likewise shown that they entertain a favourable opinion of the plan, by ordering it to be applied on a short line from Arras.

On the adverse side of the question are ranged amongst others the names of Mr. R.Stephenson, Mr. Bidder, Mr. Nicholson, and Mr. Herapath.