NAVIGATION OF THE NORTH ATLANTIC.The following will be found important to masters of vessels in the Newfoundland, Quebec, and British America trades:—•EXTRACT OF A LETTER FROM DARTMOUTH, DATED SEPT.ADDRESSED TO TIIE COMMITTEE OF LLOYD’S.On perusing the public prints, a day or two since, my attention was particularly attracted to an account of the loss of the brig Spence, Michael Wilson, master, at St. Shott’s, in the island of Newfoundland, on the 16th of July last; and from the late melancholy loss of his Majesty’s brig Drake, at the same place, I am induced to offer a few observations on the reasons why thdse losses have so frequently occurred at that place within a few years, and without the survivors being able to account for them, and also to point out the means of avoiding them in future, if those means which are in the possession of all commanders of vessels are duly attended to. Being a native of the island, having been nearly 20 years engaged- in its fishery, and the greatest part of that time having been spent in close attention to its duties, will, I trust, entitle my ob* serrations to some consideration, particularly when 1 state that they are the result of information derived from tiie oldest and most experienced boat-masters who have been employed in fishing from the centre of the eastern to 'the western coast of the island, and more particularly at Cape St. Mary's. Those men, though unlearned, I have found entitled to consideration ; and their practice has proved their conclusions to have been correct.u It is well understood by those boat-masters that there is in general a strong current setting in from the eastward, along the western coast, which alter passing Cape Pine, tends more towards St. Mary’s and Placentia bays. This current, in my opinion, is sensibly felt, at least twenty leagues S.W. of Cape Pine, and becomes more rapid as you approach the laud, its velocity increasing as the wind favours it, but at all times of sufficient magnitude to endanger the safety of any ship approaching, from the south and west, in foggy weather, aud being ignorant of its existence. In order to avoid .the danger arising from this current, the fishermen, in foggy weather, and when returning from the western coast to their homes on the eastern coast, invariably use the lead, depending more on their depth of water than their compass, and never approaching nearer the land than 35 fathoms of water. The ground being more of an inclined plane on the west coast than on the east, you will find that depth of water a considerable distance from the land; in fact, sufficient to ensure the safety of any ship passing the coast. On passing to the eastward of Cape Race, the ground becomes more broken, and the depth of water increases so very fast, tliat in your course from Cape St. Mary’s to avoid Cape Race, you will, when to the eastward of it, find yourself in 50 fathoms, and when advanced a very short distance further, in 60 and 70 fathbnte of water ;1 consequently, you are then clear of any land, and at liberty to pursue your course to the eastward, or run along the eastern coast, as circumstances may require. I do not perceive that any advantage would arise by Government establishing a post at St. Shott’s to fire fog-guns, 2s we have at times known vessels! lost in the neighbourhood of St. John’s, where that practice, is invariably fallowed. A due attention to the lead and line should be enforced; for if men will not take care of themselves, it is hard to expect others to do so for them.”