In comparing all these continental railways with those of our own country, we find many instructive differences. In the first place, the engineering, as we lately remarked, is much less daring; there is not so much capital at command, and the engineers, therefore, bend to difficulties instead of cutting through them. Still, there are not wanting engineering works of great magnitude. One such is the great railway bridge over the Vistula, near Bromberg, the first stone of which was laid with much form by the king of Prussia some short time back, and which will form one link in the chain from Berlin to Koenigsberg. Another is the double railway bridge over the Elbe at Dresden, opened in April 1852, having a railway on its eastern half, and an ordinary roadway on its western. The stupendous Cologne Bridge will be for the future to talk about: at present, not a single railway bridge, we believe, crosses the Rhine; so that Western Europe is, in fact, not yet connected by the iron pathway with Eastern. Among the many thousand miles of continental railway, there must, of course, be numerous constructions of great skill and magnitude; but the ratio is small compared with those of England. Another feature, is the great prevalence of single lines of rail. In England, there is so much wrangling against single lines, and so great a tendency among directors to think that there _ought_ to be traffic enough for more, that double lines prevail almost everywhere. In the German railways, double lines are laid down only in places of great traffic--single lines being the rule, and the others the exception. Where there are only three or four departures per day, which is the case on most German railways, one line, with carefully-managed sidings, is amply sufficient. 'Express trains,' and 'first-class trains,' and 'special trains,' and anything which disturbs the steady jog-trot mode of proceeding, are very little known in Germany; the general speed, including stoppages, is about twenty miles an hour. Although the first-class fares are only a fraction above 1-1/2d. per mile, and the second-class just over 1d., yet the Germans travel so cheaply, and mix among each other with so little exclusiveness, that it is said only 3-1/2 per cent. of the whole number of passengers travel by first-class, and 74 per cent. by third-class; the ratios in England being 14 and 46 per cent. respectively. One apparent effect of these very low fares is, that although the railways are for the most part cheaply constructed, the net profits are not supposed to exceed 3 per cent. on an average; but if the fares were higher, perhaps the number of passengers would be so reduced as to lessen the net profit.