Capt. Synge, of the Royal Engineers, has laid a proposition before the Geographical So ciety of England* f i new Best India route by way of the St. Lawrence and the great lakes, with their extension chain including Rainy Creek, Lake of the Woods, and Winne-peg, with the rivers which fall into the latter lake on the eastern slope of the Rocky Moun tains ; thence the route continues westwardly to Vancouver's Sound. There are now on this route fifteen hundred miles of inland na vigation, soon to be extended four hundred miles by the construction of the Saut St. Mary Canal; and the same may be extended by occasional artificial connections almost to the base of the Rocky Mountains, which are re presented to be at that point but fourteen hundred and fifty eight feet above the level of the sea. The advantages claimed are, that it is three thousand miles nearer than any other mail route to Australia; the inland por tion lies entirely within British territory, and instead of requiring sixty or eighty days for transit, would only require forty to fifty.