The outward European mails would arrive at Halifax on the 20th and the 4th or 5th of every month, and at Havannah on the 31st or 1st, and 15th or 16th of each month. Leaving Halifax on the days above mentioned, the steamers, by way of New York, would reach Havannah on the 30th and 15th of each month, and, allowing two days at Havannah, return to Halifax by way of New York, on the 14th and 29th, eight days before the arrival there of the outward European packet, giving abundance of time to rest. This steamer will bring back from New York the answers to the letters received from Europe for the return packet from Halifax to Fayal. These letters would reach New York on the 23d and 8th of each month. The stoppage at New York by this steamer returning northward could not be beyond one or two days. To meet the West Indian and South American packets returning to the central point, Fayal, the steamer, with all the North American correspondence, must leave Halifax on the 29th or 30th, and the 13th or 14th of each month. Considering attentively the calculations here made, it will be (p. 020) found that they correspond accurately, and that in practice these will work admirably, and without confusion or delay--points, in an affair of this kind, of the greatest importance. The other plan, by which the communication between North America and the West Indies can be opened up and carried on, is between New York and Jamaica, by the Havannah. After considering it, in all its bearings and details, the former will appear to be the most economical and eligible. Calculating the whole of the General Plan to be carried into effect, and by steam, the outward mails from Europe, _via_ Fayal and Halifax, would arrive at New York on the 7th or 22d, or the 8th and 23d, of each month; and those for the West Indies, _via_ Fayal and Barbadoes, at Cape Nichola Mole, Hayti, on the 11th and 27th, or 12th and 27th, and at Jamaica on the 13th and 28th of each month. The mails from the westward and southward of, and for Jamaica, would consequently return to that island on the 7th and 22d of each month. The distances and time taken in three ways between Jamaica and New York, by Havannah, would be-- (No. 1.) Geo. Miles. Days. New York to Havannah 1140 6-1/2 Havannah by Matanzas, to St. Jago de Cuba 630 4 St. Jago de Cuba to Kingston, Jamaica 170 1 Jamaica " 2 Jamaica to Cape Nichola Mole, by St. Jago 305 2 Cape Nichola to Havannah, by Matanzas 540 3 Havannah, Coals, &c. " 1 Havannah to New York 1140 6-1/2 ----- ------ Totals 3925 26 (No. 2.) Geo. Miles. Days.