of probability be assigned as the cause of their loss. While mentioning the fate of these ships, the term mysterious cannot be applied to them as to their disappearance. If a ship must be abandoned in the Atlantic during winter from any cause, her crew have but an indifferent chance of escape from death. An ordinary gale would quickly swamp the crowded boats, probably before they cleared the ship; and supposing them to leave her without accident, cold and hunger would quickly do the work which the sea had left undone. Neither am I surprised that no remnant of the wrecks of these vessels was ever found on the ocean by which they might have been identified, although a diligent search was instituted for them. In whatever manner they disappeared, I believe the locality to have been on the northern point of the great circle forming Capes Race and Clear. If this supposition is correct, any wreck which might have floated would be more likely to be washed up on the western shores of Ireland or Scotland than to be seen by the casual voyager, whose course would almost always lie to the southward of this track. It must also be borne in mind that the Gulf Stream has a perceptible drain to the N.E. about this part which would slowly carry all drifting matter in that direction over an unfrequented part of the ocean.

The steamers engaged in the Montreal trade are the greatest sufferers from fog; compared with theirs the mishaps of the other companies dwindle into insignificance. It is said that one vessel has annually been lost on the average during each of the last eightyears. Incorrect compasses, pushing on at improper times, and errors in judgment, have doubtless aided the fogs of the estuary of the St. Lawrence in stranding so many noble ships. Still no one can deny the fact that the dangers of this route surpass all others; enough are they indeed to baffle the skill of the best seamen in the merchant marine.

In the spring it is not uncommon for these fogs at the entrance of the straits of Belleisle to last for three days, rendering it impossible to run with safety, and more than one steamer has been backed off when almost touching the rocks, without those on board being able to recognize the locality.

It is fortunate for navigators that the greater part of the regions of North America, where fogs prevail in more than an ordinary degree, have a bold and safe coast. Cape Race may be approached within a few yards, and stories are told of marvellous escapes by Atlantic steamers from the rocks at the base of this well known headland. How, when the cliffs were looming over their mast-heads, and yardarms barely clear of its precipitous rocks, the coolness and skill of one man had saved hundreds of lives from certain death.

I once had a narrow escape in entering Halifax. Fog had prevailed over portions of three days, and the ship had been navigated solely by log and lead. At two o'clock in the morning (October) the depth of water indicated that the ship was not far from Samb'ro Lighthouse. The engines were stopped, and at daylight, in a slight clear, a pilotboat was seen close to. When the pilot came on board, his bearings agreed so well with ours, that there was no hesitation in setting on

the engines at full speed when the pilot wished it. Occasionally we both stooped with the hope of seeing it by peering through the lower fog. Suddenly a faint muffled sound struck my ears, and before I had time to think what it could be, the fog rolled back, and the white foam of the breakers on the Sisters Rocks was seen close to. The helm was put down, but so imminent was the danger, that the seamen who were forward jumped off the forecastle as the ship came round, believing escape impossible. There was a Providence watching over us on that day, for had the fog remained even a few seconds longer, we should have been in the middle of the breakers. It was a lesson cheaply bought, and one which taught me not to rely on any pilot when the land and leading marks were not in sight. A piece of advice which all will do well to follow.

Fogs magnify and distort objects in a singular way. I have known a bird to be mistaken for a sail. Not long since the pilot of one of the Atlantic mail steamers ran her on shore in coming out of Queenstown Harbour, by mistaking a small fishing buoy for one of those which mark the channel.

In the Baltic, during the spring of 1854, the sailing ships of the allied fleets cruizing off Gothland, ran great risks of collision during the prevalence of the fogs of that season; but the sea was so smooth and the air so still that no accidents took place.

The lightest breeze is generally sufficiently powerful to roll back these fogs to the horizon; but the breeze is no sooner gone, than the fog may be seen closing in again. When this occurs late in the day, it seldom clears before next morning. Steamers are compelled to exercise an extraordinary degree of caution at such times, because in many parts of this sea the lead is a poor guide either on approaching the coast or the many outlying rocks off it.

While alluding to fogs and the difficulties with which they beset the navigator, there is another phenomenon, which, although not so dangerous, claims some remark. That extraordinary phenomenon, mirage, is frequently seen in the season of spring before the sea water has attained much increase of temperature, while the ice is melting under the sun's rays. On one occasion I witnessed the inverted images of the English fleet off Gotska Sando well above the horizon, although they were thirty-three miles distant. Each ship was perfectly distinct from her neighbour, and appeared about the same size as they would have done when fairly within the range of vision on a very clear day. At the time when fogs prevail in the Baltic, there are days which are delightfully pleasant. A cool light air fills the upper sails, while the surface of the water is not broken by a single catspaw. The best Italian skies are not to be compared to these. They impart a cheerfulness and vigour to the system that renders life enjoyable, a buoyancy of spirits that makes the monotony of a sailor's existence even more agreeable here than in any other region of the globe, not to except even the enticing "dolce far niente" days of that fair clime.

The fogs of the Pacific, like those of the Atlantic, have their peculiarities. Among the worst may be considered those between the

Chincha Islands and Lobos and off Casma. These seldom reach far into the bays, but appear to extend more from headland to headland, and reach on an average to about twenty miles from the shore. Those of January, February, and March are the most intense, lifting a little about noon. The mail steamers of the Pacific Steam Ship Company are often seriously incovenienced by them, and more than one of which vessels have been wrecked.

On all our principal leading lighthouses and lightships in time of fog, we require a better method of warning the mariner of his approach to danger than the present old fashioned one of bell and gong. To be thoroughly effective, the alarm should be heard from a reasonable distance, superior to the unavoidable noise with which a steamer is always attended in a greater or less degree with her engines at work. In running for one of our crowded harbours I have on more than one occasion missed all fog signals and anchored. Afterwards, when the

fog has lifted, I have found myself close to them.

A powerful fog horn on each of our most important turning points, would be of inestimable service to commanders of steamers; the Skerries, for example. Many a wreck has occurred on the Arklow or the Blackwater Banks from the fact of this lighthouse having been passed without seeing it. The best seamen among the many good ones of the mercantile marine of Great Britain, have begged that one might be established there; but the Brethren of the Trinity House, up to the present time, have disregarded all that has been urged upon them to obtain it. Perhaps they may have reasoned that few vessels have been lost near the Skerries. This may be quite true! bút in avoiding Scylla they have drifted on Charybdis, in the shape of sands of the more dangerous Irish coast. One glimpse of a well known landmark, in taking a departure, is of more value to the navigator than a score of casts of the lead afterwards. With steam or a leading wind, any ship, with her compasses reasonably correct, after knowing her position off the Skerries, may run fearlessly through the thickest fog of the Irish Channel. But, and "here is the rub,"-on the contrary, when the Skerries have not been seen, all is doubt and hesitation! even when the lead is used, and then the chances are in favour of the vessel being lost, not on the dangerous Skerries, but on the Irish rocks fully as dangerous as they are!

It is tiresome, besides being thankless, to be always harping on the same string, so frequently have I alluded to compass errors already. But experience convinces me that a better system of placing and adjusting this first of the mariner's monitors is absolutely necessary. In sailing ships with steel yards it is an admitted fact that the deviation changes whenever the sails are trimmed, as the compass is generally placed in the direction of the yard-arm when braced sharp up. Now a danger like this must occasion the greatest anxiety to all on board, as an observation which is correct on a wind is useless when running free. If the mizen mast and yards were of wood, a position might be found, sufficiently distant from the stern, where the binnacle could be placed so as to be beyond the influence of the main-yard,

which appears to be the great enemy and disturber of the compass; it is singular how little interest shipowners take in this important subject. Their ships make their voyages and they are satisfied; but I am certain that many frequently lose ten miles in the twenty-four hours from compass errors, which might be avoided by good and correctly placed compasses. A first class compass, will, if properly cared for and looked after, last as long as the ship; will pay itself over and over again the first voyage, and certainly where fogs prevail will prove an inestimable benefit to all on board. But, unfortunately, John Bull, in spite of his boasting, is slow to take advantage of many of the most useful and necessary inventions of the age. Were it not for the spur of competition, his best captains would doubtless lag on the road. But he ought to know that too many men of the last generation still hold important maritime appointments, that there are men who have never navigated a steamer against time in all weathers, and who believe that their darling old fashioned idea of pounding the bottom, is a panacea for every position of danger or uncertainty in which a ship may be placed! How long is this to last? is the present question of

MERCATOR.

On the subject of fogs our readers will no doubt remember the excellent remarks of Dr. Kelly on those of the St. Lawrence in our volume for 1845, and some important observations by Mr. Gill, Master, R.N. But we meet with some remarks on the Electro-Negative character of fogs in the Mechanic's Magazine of the 14th inst., which appear to invest this phenomenon with an influence on the compass that seems likely to become a subject for inquiry among our scientific navigators. The subject is not new, as we remember a case of a vessel wrecked on Holyhead in a fog, which was attributed by counsel to its influence on her compass, and which (whether the fact or not) affected the decision of judgment. Mr. Gill, abovementioned, alludes to the effect of fog on the barometer, but we have yet to learn of proof that it affects the compass. And as terrestrial objects are then invisible, the only way that suggests itself to us of deciding the question is by the sun's azimuth, an easy operation now by Burdwood's Tables. The deviation and variation being known (combining, as they do, to form the whole compass error from the magnetic meridian) the azimuth found from the sun, (which is often clear in a fog,) while the ship is surrounded by it, would, if there be any effect, show a different error; and the difference between it and the known error might thus be set down to the effect of fog. The observations would require great care, and we should be glad to learn that some one has thus settled the question, and removed another bugbear from navigation. Meanwhile we append the paper to which we have referred; but at present we cannot say that we believe in any effect whatever being produced on the compass from the prevalence of fog. Any of our readers who will show us that we are wrong in this opinion, will render a service to the navigator.-ED.]

ELECTRO-NEGATIVE FOG.

Dr. Phipson has read a paper on an Electro-Negative Fog, at the British Association, and after the reading of it Mr. Glaisher made some remarks on the blue or cholera mist, as it has been called, but we cannot make out exactly whether the two are considered to be one and the same phenomenon, much less can we tell what an electronegative fog or mist may be. We should like to have an electropositive fog described, then at least we could make a comparison between the two; but since we are not able to do that, we must try to penetrate this mystery of the electro-negative fog. We know what a fog or mist is; but if it be electro-negative that is another matter. We suppose the first thing to be inquired into is the nature of negative electricity, or into electricity both positive and negative. What, then, is electricity? or, rather, what do our savans say it is? for to them we would appeal. If they can tell us, then we may be brought nearer to the understanding of this electro-negative fog. But is it not a strange question to ask at this day? Surely we know what it is. It is familiar to us all. In how many ways do we not use it? As our swift messenger half round the world; as a beacon light to guide our ships. We use it as a motive power. We use it to plate our spoons, to ring for our servants, to catch our fish, and also to catch our thieves, to light our gas, to tell the time, and to watch our idle servants. We use it in metallurgy; we use it in the fine arts, to cast our medals, vases, and statuary. We use it in surgery, dentistry, and therapeutics. We use it to spring our mines, to fire our torpedoes, and to mark our targets, and for many other purposes-so numerous that no ordinary memory can contain them. Still, what is electricity, negative or positive? and then this blue fog?

So wonderful is this thing that we have an unquenchable desire to know it face to face, and more especially now that our learned men have found out that it is some sort of a mist, and has something to do with the most fearful of all plagues, the cholera. For this purpose we have been reading the learned authors, who treat upon this fluid or force; we have read reports of committees and commissioners, who sit and consult and take evidence upon it. We have conversed with men who are wondrous learned in this matter, and tried to get their notion of what this thing is. Then we have tried to collect the sum and substance of all that we have read and talked about it, and tried to put all these multifarious notions or opinions, or guesses, or whatever they may be called (we cannot tell; but this we know that they are contradictions one of another), into some shape or other, to be understood by us if possible; but it has not been possible. First, we are told that there are five or six kinds of electricity, if not more; that there is static electricity, voltaic electricity, thermo-electricity, magneto-electricity, photo-electricity, and we know not how many besides. Then we are told it is all the same, there is only one kind. Still we are not satisfied; for we are told by the report of a committee, that static