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WK ST AC STKAI.IA

1839

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Winds And Wbatheh, on the western coast of New Holland.By Com. J. C Wiclcham, of H-M.S. Beagle.

[In the present dearth of Nautical information, concerning the western coast of Australia, we have great satisfaction in publishing immediately, for the use of seamen, the following judicious and well digested account of the weather on that coast, by Commander Wickham, lately employed surveying it in her Majesty's ship Beagle. We have already availed ourselves of his excellent account of the Abrolhos, a part which obtained additional terrors from our general ignorance concerning those dangers. With the knowledge however thus imparted, and the chart of them which will be hereafter published by the Hydrographic Office, they will become useful to our whalers as supplying water, which is so difficult to be obtained on the Australian Coast. Our next will contain the remainder of the present paper, treating more on the North Western Coast, and will be followed by descriptions of the coast from the same intelligent and experienced officer. Our last number contained a chart of a small portion of the coast to the southward of Swan River, and in our present number is a plan of Peel harbour, in Warnborough Sound. We regret that these are not accompanied by any description, and although we have not yet met with any, these plans convey sufficient information in themselves, to afford valuable assistance to vessels on the coast.—Eo. N.M.]

The winds on the western coast of New Holland, are for the most part from some southern point, chiefly between S.S.W. and S.S.E.

During the summer, or from the early part of October to the beginning of April, they are almost constant from this quarter; but in the winter their regularity is broken in upon, by occasional winds between north and west, that at times blow with great violence, and are accompanied by heavy rain and thick dirty weather.

Near the shore, land and sea breezes appear to be regular, the former generally dying away towards the middle of the day, after having reached as far as east, from about south-east at sunrise; then follows a short interval of calm; after which the sea breeze sets in mostly at S.S.W., and draws to the eastward of south in the evening.

At times the land wind veers round the compass, and is then generally stronger than usual, blowing fresh for a short time from north-east, and bringing a parching heat from the land; upon these occasions the sea breeze comes in from a more western point, and is lighter.

At Swan River, in the months of December, January, and February, the sea breezes are very strong for intervals of from three to five days, during which time they blow fresh throughout the night, drawing to the southward after midnight, and towards sunrise to S.S.E. and south-east, but more moderate. In the middle of the day they back again to the southward, and soon to S.S.W., from which quarter they blow very fresh until midnight.

Intervals of such weather are from three to five days duration, and are followed by the like nnmber of days of moderate weather, with winds mostly off the land; sometimes strong gusts from east for a few hours, with oppressively hot weather.

ENLARGED SLKIES NO. 11.—VOL. FOR 1841. 4 Z

I have noticed, that when the sea breeze sets in from a point to the westward of south-west, it does not blow so strong, and generally lulls at sunset; but if more southerly, or from S.S.W., it is a firey breeze, and often lasts until midnight.

During the prevalence of these strong sea breezes, communication between Gages Road and the shore is very inconvenient, particularly for laden boats.

In March, the sea breezes are not nearly so strong, but are generally moderate, .and not unfrequently bring in thick misty weather from seaward with drizzling rain.

Generally speaking, when the sea breezes are the strongest, the land winds are light, and vice versa.

I cannot speak from experience of the winds or weatber during the month of April at Swan River, but I have been told, that the sea breezes are moderate, and the land winds of longer duration; calms are frequent, and the weather altogether seems to indicate tbe breaking up of the summer season. Light winds are occasionally felt from the northward, with a dull gloomy appearance between that point and south-west.

May is the month in which the winter weather fairly sets in, and it rarely happens that the middle of this month passes without the rains having commenced. This season seems to vary but little as to the time and manner of setting in,—it is ushered in by blowing weather from about N.N.E., the wind gradually veering ronnd to the westward as it increases in strength. The first of this weather usually lasts from a week to fourteen days, then comes an interval of fine weatber, generally of a fortnight's duration, and sometimes a month; after which the rains set in more constant, and the intervals of fine weather are shorter:—this weather lasts until October, and at times throughout that month.

During the intervals of fine weather the climate is delightful, and the country has a fresh and pleasing appearance; land and sea breezes are as regular as in summer, with the exception that the latter are much more moderate.

The north-west gales that occasionally occnr during the winter months, on the southern parts of the west coast of New Holland, are probably felt as far north as Sharks Bay. They blow with great violence, and are accompanied by dark gloomy weather and rain. It is then unsafe to be near the land, as tbe gale that commences at N.N.E., invariably veers to tha westward, making a lee shore of tbe whole line of coast, and between W.N.W. and W.S.W. blows tbe hardest.

Fortunately these gales give ample warning,—the barometer alwayi foretells their approach, and generally begins to fall three or four daji before the commencement of the gale; besides which, there are other never-failing indications of a northerly wind, such as the change of the current, which, (owing to the prevailing southerly winds,) usually sett to the northward, but runs strong to the southward during norther!/ winds, frequently preceding them, and giving more timely notice than the barometer.

A rising of tbe water is likewise a certain prognostic of a northerly wind, and has been invariably noticed at Swan River to precede all gales from that quarter; this, of course, can only be observed while at anchor on the coast.

Another, and perhaps equally certain sign of approaching bad weather, during the winter season, (and which is almost certain to be from the northward,) is the strength of the north-east winds. As it has been observed, that when the land winds blow strong, particularly from the north-east, and the sea breezes are light, with a falling barometer, a gale from the northward will follow. Perhaps these latter remarks are only applicable to that distance from the shore, where a ship will be within the influence of the land and the cea breezes, but as I conceive the limit of that distance to be full thirty miles off shore, a notice of such a symptom of approaching bad weather may not b« altogether useless. I am of opinion, that laud winds are at times felt as far off shore as the edge of soundings, which is not less than thirty miles, and generally between that and forty.

In latitude 30° 25' southward, and sixty-five miles from the land, soundings were got from the Beagle with 185 fathoms of line, upoa a coral bottom. Between Swan River and Houtmans Abrolhos, soundings may be had at a greater distance from the land, than off any other part of the west coast.

The north-west gales are of longer duration, in the latitude of Swan River and south of that, than they are to the northward. They do not appear to be entirely confined to the winter months, as I am told that a very heavy one was experienced at Swan River early in March, IS32; and on the 13th of December, 1839, the Beagle experienced a strong breeze from the northward, while at anchor in Gages Road, in consequence of which, it was considered necessary to let go an extra anchor.

As it may be satisfactory to know more particularly the progress of these gales, and the effect they have upon the barometer and sympiesometer, I give the details of two that were experienced in her Majesty's ship Beagle,—one at Swan River in the beginning of June, 1838, the other at Houtmans Abrolhos in the beginning of May, 1840. They may be taken as fair criterion* of the strength and duration of these gales, the latter having been experienced, probably, within 5° of their northern limit, and the former near the southern extreme of the west coast.

As our barometer had been broken in March, 1838, the register of a sympiesometer will be given in describing the gale of June in tha year; but as this instrument had been found, (by comparison with the barometer,) to act exceedingly well, it will be sufficient for our purpose; the general use of a marine barometer being merely that of a weatherglass, for which purpose, a sympiesometer is equally good, and moresensitive.

For the gale of 1840, the register of a barometer is shewn, which, although nearly 0-2 too low, will serve to shew the effect upon the mercury.

At Swan River on the 24th of May, 1838, the wind was strong and squally from N.E.b.N.,—sympiesometer standing at 30*74. During the day the oil commenced to fall, and continued falling slowly until the 30th, when it was 30-16; during the greater part of this integral, the winds were light, generally from some eastern point in the morning, and going round the compass by north and west during the day; the nights were mostly calm,-* heavy bank of clouds was collecting between N N.E. and south-west, and the whole western horizon had a gloomy appearance. On the evening of the 30th, the water had risen considerably at the anchorage, and the stream ran to the southward. A fresh breeze also set in from north-east, and gradually veered to the northward, as it increased in strength. On the 31st, it blew hard all day between N.N.E. and N.N.W.. with dark squally weather,—much lightning in the south-west, and heavy rain, that continued all night. On June the 1st, the gale was at its height, and at 8 A.m. (the sympiesometer having fallen to 29-93,) was blowing a hard gale, with heary squalls and rain from north-west; towards noon the wind veered to west, but sUll blew very hard. The sympiesometer now began to n*-, and in the evening the wind was W.S.W., and had moderated considerably; the weather was also clearer, although heavy clouds still hung on the western horizon.

The next morning, (the 2nd,) the sympiesometer had risen to 30-26, but this was much too sudden a rise, (0-33 in 24 hours,) to allow us to suppose that the favourable change in the weather was to be of long continuance. During the day the oil began to fall again, and the wind veered to west and north-west, and on the 3rd blew harder than ever, with heavy rain, thunder and lightning, and with the exception of occasional intervals, when the wind moderated, this weather continued until the 10th. The wind during this time was variable, between N.N.W. and W.S.W. Sympiesometer between 29-81 and 30-16, falling with the north-west winds, and rising as the wind veered to west and W.S.W.*

This gale, which may be said to have been of ten days' continuance, caused a heavy sea upon the coast:—the oldest residents at Swan River said they had never experienced so heavy a sea before. On the 10th, the glass commenced to rise steadily, and the weather was fine, with light variable winds, until the Beagle sailed on the 20th.

Owing to the security of Owens anchorage, and the good quality of the bottom, the Beagle rode out this bad weather, without causing the slightest apprehension to any one on board; but had a merchant vessel been in Gages Road, in all probability she would have added one more to the list of wrecks, that have already done top much in prejudicing strangers against the Swan River settlement.

The gale of May, 1840, at Houtmans Abrolbps, commenced in • similar manner with that already described, but being in a lower latitude, was of shorter duration, and the indications did not precede it such a length of time, still they were in every respect similar.

This gale cpmmenced on the 2nd pf May, in the evening, and lasted until the evening of the 4th.

On April the 29th, the barometer stood at 30-17, (having been some

.».* Jt|W'" *"* 8een that tne*e gate" have 8" the character pf the usual hurricanes of *Pe At,aI>'>c, and the typhoon of the China Sea, but being in the souther* hemisphere the shifts of wind draw round to the Ufl instead of the right, in each cue going with pie sun, and confirming the theory of Mr. Redfield and Col. Reid.

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