In a postscript to the letter, dated the lath August,
which we have quoted from in oar political summaries, the writer mentions, that the Pre- sident steamer arrived at N::.•.v York the preceding day, after a passage of fifteen days and a half; and that the Acadia (Cunard's line) came in on the morning of the IStb, aiter a passage of twelve days and a half. Such is the wonder-working power of steam, that the passage across the Atlantic tnny now be calculated with almost as much certainty as the arrival of a stage-coach. Our correspondent adds—" You will re- ceive in England, before the 4th of September, answers to letters from England of the 4th of August." As the Great Western arrived on the 1st, the interchange of couununication between the two countries was completed three days within the month.
The Royal moil steam-ship Britannia was to sail from Liverpool yes- terday afternoon, for Halifax and Boston. She carries out above eighty passengers ; amongst whom are Lard Viscount Falkland, the new Co vernor ot Nova Scotia, ad his suite. The Britannia is expected to reach Halifax on the 15th instant and Boston on the I lib.