But with all this, our already crowded river is becoming overcrowded, to remedy which a promising project is afoot for a new dock at Plaistow Marshes, a few miles below London Bridge, where a fleet or two of the ever-multiplying ships may find accommodation. The extent is to be ninety acres, with a mile of wharfage, and nearly 200,000 feet of fireproof warehouse-room. How far this will meet the want, may be inferred from the fact, that the tonnage of the port of London has increased from 990,110 tons in 1828, to 2,170,322 tons in 1852. And if an experience of three years may be relied on, the increase is to be progressive; for of new British-built ships in 1849, the amount was 121,266 tons; in 1850, 137,530 tons; in 1851, 152,563 tons. Such an augmentation shews, that we have nothing to fear from repeal of the Navigation Laws; and the fruits of unrestriction are shewn in the increased size of ships, in their improved external form, and interior accommodation. It may be mentioned here, that the Lords of the Admiralty have ordered that all ships' log-books sent to their department shall be true and faithful copies, with a track-chart of the winds experienced on the outward and homeward voyage, in addition to the usual information. Steam-vessels are to keep a record of the quantity of coal on board at noon each day--of the time it is estimated to last--and of the number of miles steamed in the previous twenty-four hours. Railways, too, exhibit signs of progress. The gross proceeds of the traffic for the first seven months of 1851 amounted to L.8,254,303, while for the same portion of the present year the sum is L.8,504,002; a result the more striking when it is remembered that last year we had the Exhibition. The new lines opened in 1851 comprised not more than 269 miles--the smallest amount in any year since 1848--so that, at the end of December, we had 6890 miles of railway actually opened, and 5101 miles authorised and still to be made. It is clear that the greater portion of the latter will never be attempted, seeing that people have really found out that railways are not exempt from the operation of the great natural laws of supply and demand. Some of the facts of last year's traffic are astounding: the total number of passengers conveyed was 85,391,095--twelve millions more than in the preceding year; and the aggregate returns amounted to L.14,997,459. What a difference when compared with the sum paid for travel and transport twenty years ago! In the United States, the number of miles of railway actually open is 13,200, which, by the end of 1855, it is expected will be increased to 18,000 or 20,000. There are 27,000 miles of electric telegraphs, but in this estimate the five or six lines between any two places are all counted. On one of the lines from New York to Washington, 253,857 messages were sent in the year ending last July, the toll for which amounted to 103,232 dollars--over L.20,000.