The Nautical Magazine: A Journal of Papers on Subjects Connected with ...

Elementary Treatise on Steam, more particularly as applicable to the purposes
of Navigation, with a familiar dsscription of the engine, by Robert Otway,

Com. R. N. 140.

Narrative of an Expedition into the interior of Africa, by the river Niger,
in the steam-vessel Quora and Alburkah, 1332-4. By Macgregor Laird, and RA
B Oldfield, surviving officers of the expedition 212

Celestial scenery; or the wonders of the Planetary system displayed Illus-
trating the Perfection of Diety and a purality of worlds. By Thomas Dick, L LD
&c, 233

South America and the Pacific Comprising a journey across the Pampas and the
Andes, &c By the Honourable P Campbell Scarlett 284

Outward Bound; or a Merchant's Adventures By the author of Rattlin
the Reefer &c 284

Simplicity of Living, Observations on the preservation of health in infancy
youth manhood and age &c By J H Curtis Esq 284

Life and correspondence of
fleet &c By Edward Pelham

New Charts:-

Johu Earl of St Vincent G C B Admiral of the
Brenton Captain R N 354

Ballyshannon harbour West coast of Ireland 284

Dragon's mouth (Bocas de Dragos) Trinidad 285

Africa, West coast sheet 1 By Lieut Arlett R N 235

Africa, West coast sheet 4 285

Shetland islnads surveyed by George Thomas commanding H M S Investigator

235

Gulf of St Lawrence Magdalen islands Surveyed by Lieut. P E Collins R N 501
Bay of Seven Islands By Captain H W Bayfield R N 501

Gulf of St Lawrence Mingin Islands western sheet By Lt HW Bayfild R
N. FA S 501

THE

NAUTICAL MAGAZINE.

ORIGINAL PAPERS.

JANUARY, 1838.

REMARKS ON THE ST. LAWRENCE, BY CAPTAIN H. W. BAYFIELD, R.N.

1. Former Charts of the St. Lawrence.-2. Massey's Sounding Machine.-3. Variation.-4. Deviation.-5. Local Attraction of Rocks.-6. Ice.-7. Fogs.-8. Winds and Weather.-9. The Marine Barometer.

1. THE navigation of the Gulf and River of St. Lawrence has been supposed always to be attended with a considerable degree of difficulty and danger, and the numerous accidents which are constantly occurring to vessels there seem to show that the opinion is well founded. The want of soundings, in many parts, near the shores; the irregularity of the tides and currents; the severity of the climate, especially towards the close of the navigable season; and, above all, the frequent fogs, are difficulties which may well cause much anxiety in the mind of the seaman, and which call for the exercise of all his vigilance, prudence, and ability. Nevertheless, a very large proportion of the losses which annually take place, may, I think, be attributed to other than these natural and irremediable causes. Erroneous charts, a want of knowledge of the direction and strength of the tides and currents, and a false variation of the compass, are, although not the only, certainly the most frequent, causes of shipwreck in the St. Lawrence. It is hoped that these last will be removed by the survey which has been made by order of the Lords Commissioners of the Admiralty; and by these directions and remarks, written also by their command, in order to accompany the charts.

Of the various charts of the St. Lawrence which have hitherto been in use, those of Major Holland, re-published by Des Barres in 1778, are the least inaccurate, yet the least in general use. The others appear to be taken from them with alterations, which, it seems, rest on no better foundation than the fancy of the chart makers, who, in their compilations, from materials generally inaccurate, appear to have considered the latest as necessarily the best information. The effect ENLARGED SERIES.-NO. 1.-VOL. FOR 1838.

of this has been the retention of old errors and the addition of new ones, for it so happens that the most recent charts of the St. Lawrence at present in use, are the most erroneous of any. In Des Barres' charts, although thus mentioned as the best, the errors and omissions are numerous and important. The soundings are generally incorrect, frequently so much so as to be directly contrary to the truth; for he occasionally shows a moderate depth of water, where there should be 100 fathoms or more, and in other places a great depth where there is bottom to be found with the hand lead. Commanders of ships having found that they could not trust to the soundings in these, and the other charts, have considered it of no use to sound, from which many fatal accidents have occurred within my own knowledge.

2. In the Admiralty charts will be found accurate soundings, taken with Massey's patent sounding machine, which gives the exact perpendicular depth, independent of the effect of currents or drift of the vessel. I strongly recommend the use of this excellent instrument, with which every vessel, in my opinion, ought to be furnished. It is not expensive, and will last, with care, for a long period of time: correct soundings may be obtained with it in thirty fathoms of water without heaving to, if the vessel be not sailing at a rate exceeding seven knots; and no vessel ought to be permitted to run faster in a thick fog, or dark night, when in the vicinity of land, or other danger. Furnished with this instrument, or, instead of it, with Burt's buoy and nipper, and with correct charts, a vessel may be run in safety up the St. Lawrence as high as Green Island. In short, there, as elsewhere, correct soundings are the best of all guides to the navigator.*

3. The variation, given in Des Barres' charts, was probably correct for the time when the charts were made; and though greatly changed since, has been copied nevertheless into most of the charts in general

There is no difficulty in the use of Massey's patent sounding machine, and it is sold, accompanied with directions for setting, reading its indications, &c. The common deep sea lead line is not strong enough to bear the strain of the lead and attached machine. When the vessel is going fast through the water a superior line should be employed for the purpose. When sailing at a rate not exceeding five knots, bottom may be struck in fifty fathoms of water, and when going slower, at still greater depths; but the hollow cylinder of the wings will seldom bear the pressure, at depths much exceeding 100 fathoms. The deep sea lead line, with the machine attached, should be passed forward, from the weather quarter of the vessel, outside all, to the weather cathead, or bowsprit end. If going slow, it may be dropped, very conveniently, from the weather gangway, abaft the fore rigging, taking care, in all cases, to drop it perpendicularly into the sea, and not to throw, or swing it, as is sometimes carelessly done. An iron staunchion, "to ship and unship," on either quarter, as required, with a small snatch-block attached, to pass the line through, will enable four or five hands to walk the lead-line in with ease and expedition. Mr. Massey has recently much improved this machine.

use. For instance, in some of those charts the variation at Anticosti is given as 17° west, too little by three quarters of a point. The effect of this upon the run of a vessel from the entrance of the gulf to Anticosti, or from the latter to Point de Monts, will be obvious to any seaman, and has doubtless occasionally been one cause of shipwreck.

4. There is another source of error, independent of charts altogether, which it is astonishing to find obtaining so little attention, particularly in the merchant service, considering how much has been written concerning it of late years. I allude to the deviation, or local attraction, of the needle. This subject may be seen fully treated in Mr. Barlow's treatise on magnetic attraction; and Scoresby in his works on the arctic regions, and on the Greenland whale fishery, gives many valuable and practical directions respecting the methods available under different circumstances, for finding its amount in various positions of the ship's head, and applying a correction according to the course steered. The amount of error from this cause will be a point of the compass in most vessels, and, in particular circumstances, may become twice that quantity in those latitudes.

5. An opinion is prevalent that the compasses of vessels are disturbed in the Gulf and River St. Lawrence, and such disturbance has been attributed to the magnetic ores of iron in the hills, particularly those of the north coast. The magnetic oxide of iron does exist abundantly, and attracts the needle very powerfully at some points, particularly along the coast from the Bay of Seven Islands eastward. Among the Mingan Islands, we found the variation to vary from this cause from 19° to 31° west. At Port Neuf, and on Manicoagan Point, the needle was also disturbed. But these effects were only noticed when the instrument was placed on the shore. In one or two instances only, when sailing within two miles of the shore, have we observed any effect of the kind upon the compasses on board the Gulnare, the schooner in which the survey has been carried on, and then only to the amount of a very few degrees.

When running from place to place, at greater distances from the coast, nothing of the kind has been noticed; so that I feel sure, that in nine cases out of ten where this source of erroneous reckoning has been alleged as the cause of accidents to vessels, they originated either in errors of the chart, or in the local attraction on board the vessel.

6. Among the difficulties of the navigation, may be mentioned the ice. In spring the entrance and eastern parts of the gulf are frequently covered with it, and vessels are sometimes beset for many days. Being unfitted for contending with this danger, they often suffer from it, and are occasionally lost; but serious accidents from this cause do not frequently occur, because the ice is generally in a melting state from the powerful effect of the sun in spring. In the fall of the year accidents from ice seldom occur, except when the

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