Trains, owing to this trough, run twice a day in each direction without stopping, between Holyhead and Chester, 84½ miles. The weight of these trains, exclusive of the engine and tender, is fully 80 tons; but the weight of the American special express, exclusive of engine and tender, did not exceed 20. A few words with respect to the fastest trains on the Continent. Previous to the 1st of April of this year, the mail trains between Calais and Paris completed 203 miles, with 15 minutes of stoppages for passenger accommodation, in 5 hours and 50 minutes, about 33¼ miles an hour. Since the opening of the railway between Calais and Boulogne, the mail trains go to and come from Paris _viâ_ Boulogne. The distance is shortened to 186 miles, and the journey is performed, 15 minutes of stoppages for passenger accommodation being allowed, in 5½ hours, or at the rate of 34 miles an hour. The “Rapide,” the night mail train from Paris to Marseilles, completes 537 miles in 15 hours 45 minutes, or at the rate, for this long journey, of 34 miles an hour. The day mail train from Paris to Bordeaux takes 10½ hours, a distance of 366 miles, or at the rate of 34¼ miles an hour. It is the fastest mail or express train in France that goes over a large extent of railway mileage, but its pace is 3¼ miles an hour less than the Scotch Limited Mail as far as Perth, 4¼ less than that of the Irish Express Mail, and 8¾ less than the express train of the Great Western from London to Exeter. There is, however, one train in France that travels more rapidly for a short distance,—the 1·0 p.m. express from Paris to Rouen. It completes 85 miles without a stoppage in 2 hours 22 minutes, or at the rate of 35½ miles an hour. Comparing this speed with that of the London and Dover express mail trains, it is less by 6½ miles an hour. There are two express mail trains in Belgium analagous to those between London and Dover. They are the fastest in that kingdom. They complete the 78 miles between Brussels and Ostend in 2 hours and 17 minutes, with 3 short stoppages, or, at the rate of about 34¼ miles an hour. There is a double daily postal service between Cologne and Berlin. The distance, 391 miles, is accomplished in 12½ hours, or at the rate of a little more than 31½ miles an hour, including stoppages for the refreshment of the passengers, amounting to nearly an hour on the whole journey.