not so great as that of Grenada, and its level is said to be twenty-eight feet three inches above the latter; its nearest approach to the Pacific is ten leagues in a direct line. According to Mr. Bailey, I understood Captain Belcher visited this part of the country about eighteen months or two years ago; his information will of course be more authentic.

On the road to Leon, about three leagues from the town of Grenada there is a remarkable brackish pond called Apoyo, apparently contained in the crater of an extinct volcano, which does not ebb or flow, and is not sensibly diminished by evaporation. In the vicinity of Massaya there is also a small fresh water lake; they are both, no doubt, the result of volcanic agency by which this part of the isthmus has often been violently convulsed.

The Lake of Grenada, or Nicaragua, is connected with that of Leon or Managua, by the river Panaloya, which according to Mr. Bailey's survey has its entrance into the former in latitude 12° 10' N., longitude 85° 50′ W., bearing N. 25° E. (true) from the battery of Grenada, from which it is distant fifteen miles and a half; its exit from the latter, or Lake Leon, is in latitude 12° 15′ N., and 86° 34′ W. longitude.

This communication between the two lakes, which in Roberts's Narrative is asserted to be effectually shut up by an effusion of lava, varies in its width from twenty-five to one hundred fathoms, and has a depth of from three to eighteen feet in the navigable parts of it. Mr. Bailey makes it eighteen miles long, including all its windings, but as the distances in his survey of San Juan were found to be rather short, I think we may fairly allow an additional mile or two, making its actual length inclusive of all sinuosities, to be twenty miles.

It is navigable for canoes as far as the village Pasquel, situated three miles and a half from the Lake Leon, beyond which for the distance of nearly a mile the channel is so superficially imbedded by a stratum or ledge of rocks, that in the dry season the stream is confined to a few water-worn fissures; but after a continuance of rain, the channel is overflown, and the water rushes over the rocks with great impetuosity.

Near the village of Tipitapa, not far from Lake Leon, there is also a fall of nearly thirteen feet, so that if ever a navigable communication is to be effected between these two lakes, this part of the Panaloya is not available in its present state. Adjacent to it there are several settlements.

Viewing these lakes as the grand reservoirs of numerous mountain torrents, and rivulets, from which the river San Juan is the only outlet, it must necessarily happen that their depths will vary with the change of season; accordingly we find by Mr. Bailey's registration that there is a difference of six feet six inches in the depth of Lake Nicaragua between the wet and dry season, but of course this is not invariably the

same.

The evaporation over an area of nearly 3,150 square miles, where the temperature ranges throughout the year between 75° and 90°, in conjunction with the continual efflux by the river, will effectually keep in check any extraordinary overflow, and must be taken into account in making a pluviometric calculation. Before leaving Grenada I must again express my thanks for the attention we received from Mr. Bailey

and his friends. To him I am chiefly indebted for the little information I have been able to pick up, and only regret that our stay had not been longer.

TEMPORARY RUDDER.

H.M.S. Mastiff, Orkney, Oct. 26th, 1840. SIR. Of all the accidents to which a ship is liable the loss of her rudder is allowed to involve the most serious consequences, and although many ingenious expedients have from time to time been devised to remedy this evil, yet owing to complication in the construction of the means, or difficulty in application, the question still remains open for useful inquiry; this, I tender as my excuse for troubling you with the following plan for shipping and securing a temporary rudder at sea; and if you consider it deserving a place in your valuable periodical, you will oblige me by its insertion.

I am, Sir, your obedient servant,

Let all ships before being undocked be fitted with four eyebolts in the sternposts, as in Fig. 1. Chains about the size of the ship's topsail sheets to be rove through each; they, until wanted, may be stopped neatly up the sternpost, and the ends brought inboard through the rudder hole.

Let two pieces of iron, or temporary gudgeons, be forged in the form of Fig. 2, to be held in charge as part of the ship's stores; the circular part to be of sufficient size to slip easily over a spare topmast of the particular rate, and the jaws to be of the exact model for the reception of the sternpost; these are the precautions necessary, now for their application.

Let a temporary rudder be constructed according to the plan proposed by Sir Thomas Pakenham, agreeing in every particular with the exception of calling into use a lower cap; the temporary gudgeons to be built into the rudder at distances corresponding with the bolts in the sternpost: the chains to be shackled to the jaws of the gudgeons on their respective sides, and their remaining ends to be led, the lower to the main and the upper to the mizen channels. When the rudder is lowered into the water it will be evident that, with a hawser to its head to bring it through the rudder case, and the sure direction given it by the chains to the sternpost, the operation of shipping it is rendered both easy and certain.

Fig. 3, represents one of the gudgeons in its proper position, the length of the neck serving to keep the rudder clear of the old gudgeons, and broken pintles; the depth of the jaws keeping it steady on the sternpost, and the circular part embracing the spare topmast, which will revolve freely, rendering the steering of the ship as simple and correct as with her proper rudder, &c.

189

VOYAGE OF H M.S. BEAGLE, ON A SURVEY OF THE COAST OF AUSTRALIA. By a Naval Officer.

(Continued from p. 39.)

On a subsequent visit, we had the pleasure of meeting with, and sharing the hospitality of Mr. Curr, and received much useful information from him; .among other things he spoke of the local attraction, which he, as well as ourselves had observed. Our observations gave the variation several degrees different from what it was at the last stopping place, which we knew was near the truth, and also was at variance with those taken on board.

Mr. Curr first observed this in erecting fences, and for some time was puzzled to account for the deviation from a parallel line of those he was them employed about, and the ones formerly put up; so by this it would appear, that the metal is in larger quantities in some parts of this promontory than in others. And this is the more remarkable, for in no other part of the strait we had yet visited, was anything similar found to exist. The spot which we observed on was immediately under the cliff, on the north side of the head.

The almost incredible size of the trees near Circular Head is well worthy of remark; Mr. Curr mentioned having seen one thirty-six feet in girth, in the hollow of which six people had taken up their abode, and had sufficient room to sit round a table and enjoy their meals.

Those of from twenty to twenty-five feet girth, were common within a short ride of the establishment.

From the hill on which the town is situated, the land slopes gradually to the northward, and terminates in a low spit, off which are sunken rocks to the distance of a mile or more. It was on a part of this reef we grounded, and I should recommend a good berth being given to this point in rounding, as the full extent of these dangers is not at present accurately known.

The necessary observations being completed, we left Circular Head, and with a fresh south-west wind stood away for the river Tamar, which we entered the following day, and came to an anchor in Port Dalrymple, off a white buoy on the west side of the channel, two miles from the Low Head.

As the principal object of touching here was to measure the meridian distance between it and Port Philip, there was not sufficient time to visit Launceston, the principal town, miles from the entrance; but from all we could learn, it was like most of these settlements, making rapid strides. Ships of four hundred tons now reach within a short distance of the town.

George Town on the right bank of the river about four miles from its mouth, was once the head-quarters of the regiment, which gave it some importance; but since its removal to Launceston, it has become of little note, and has now more the appearance of a village falling into decay, than the sea-port of a flourishing colony.

The river Tamar is difficult of access, in consequence of the rapid tides which set directly across the banks; but the pilot is generally in readiness to board vessels when about a mile from the entrance. The

Hebe reef, two or three miles W.b.N. from the low head is the only outer danger, and must be given a good berth to in passing, for in moderate weather it does not shew until close upon it, and there is no buoy to point out the spot.

There is an excellent lighthouse situated on the Low Head, a hundred and fifty feet above the level of the sea. It is painted white, and shews in good relief against the dark green behind, serving readily to point out the entrance to the river. By night it exhibits a bright revolving light.

On the 22nd at daylight, we weighed from Port Dalrymple, and with a fresh south-westerly wind stood across the strait towards Port Philip, carrying tolerably regular soundings from forty to fifty fathoms, over a mixed bottom of mud, sand, and shells. At noon the following day we passed Point Nepean, and stood up the west channel with three and a quarter fathoms, (the least water,) and at 7 P.M. came to an anchor in Hobsons Bay in four fathoms, with Point Gellibrand bearing south half a mile distant.

Hobsons Bay is a tolerable anchorage, so long as it does not blow strong between south and southeast; with the wind in this quarter, a short chopping sea quickly gets up. We were told that the Rattlesnake, twenty-eight, pitched her forecastle under during one of these breezes.

Vessels of three hundred tons and under, may bring Point Gellibrand to bear S.b.E., but even then, boat communication is at times cut off with Williams town, off which is the anchorage. This is denominated the seaport, it is situated on the north side of the abovenamed point, and at present consists of about a dozen houses, including the government stores. Scarcity of fresh water is a considerable drawback to this becoming a populous town; but as no vessel of burthen can pass up the river in consequence of the mud flats at its mouth; it may in time become of importance, and means will be found to remedy the evil that at present exists. The only danger in entering Hobsons Bay is from a ledge of rocks running off Point Gellibrand :- -a white buoy is now placed on the extreme.

As we had heard a great deal about the town of Melbourne much pleasure was anticipated in visiting it; accordingly the morning after our arrival, parties were formed for the purpose; some chose the walk between it and opposite where the ship lay, others preferred the view of the river Yarra-Yarra, and went up in boats, all arrived however at the same spot; were highly gratified by their visit, and found that the flourishing state of Melbourne had not been exaggerated.

It is situated on the right bank of the Yarra, just above where the salt water joins the fresh, and abreast of a ledge of rocks, called the Falls, that interrupt the course of the stream, at this point about thirty yards in width.

The number of inhabitants it is scarcely possible to ascertain, owing to the constant arrival of settlers from Sydney and Van Diemens Land, perhaps at this date fifteen hundred may be near the mark, but if the rapid influx goes on in its present ratio it will shortly become a place of considerable importance, (its locality being so advantageos) and a valuable acquisition to the crown.

The authority at present is vested in the hands of the Police magistrate, Capt. Lonsdale of the 4th regiment; but some one holding higher rank and power is daily expected to take the reins of government; this indeed is becoming highly requisite.

The whole country in the vicinity of the river is low; and some parts are said to be flooded during the rainy season; particularly that between Melbourne and the anchorage. The soil is rich and fertile, and has a pleasant appearance when connected with the surrounding, and not very distant mountains.

During our stay here the weather was generally fine, with fresh south-westerly winds; we had once to endure a suffocating breeze from the north-west similar to those so frequently experienced at Sydney, it rose the thermometer, and the following day an equally cold wind came from the same quarter.

How, and what can cause these extraordinary changes? We were constantly annoyed with them on the northern coast last summer; but then the wind was from the south-east. This would rather militate against the existence of an inland sea, and lead one to the idea that the interior of this tierra incognita is a sandy desart, somewhat similar to the continent of Africa.

We sailed from hence on New Year's day, and with a fresh southerly wind worked down to the outer harbour of Geelong, and in the evening came to an anchor in three fathoms and a half, with Point Henry bearing west a mile distant. This extensive bay was found to be much incommoded by sandy flats running off the low northern shore, and several tacks had to be made where we supposed a direct course could be shaped from the former anchorage.

From Point Henry, a grassy bluff with a small lawn-like plot, at its foot, a bank stretches across to the opposite shore, this bar has twelve feet on it at ordinary springs, and with little trouble a sufficient space may be cleared to admit vessels of moderate burthen to the inner harbour. The town of Geelong is at present in its infaucy, but from its situation on the banks of the Darwin river, where the soil is good, and extensive cattle runs being adjacent, the settlers prognosticate a large and populous town, arising in the course of a few years.

Connecting this part with the former work, detained us the next four days; when we returned to Hobsons Bay to forward dispatches to England. The same difficulty was experienced in getting out of this place as when going in; but it appeared that by keeping the Indented Head shore aboard, the only deep water was to be found leading to Geelong. We had not sufficient time to make a complete plan of this harbour, indeed as our principal work lay with the Straits, it was considered a loss of time to attempt it.

I received here the pleasing intelligence of being confirmed to the rank of master, which, although long deferred, was nevertheless welcome, and served in some degree to improve my health, which for some months had not been so good as it was, previous to my being wounded on the north-west coast.

On the 6th of January, taking advantage at four A.M. of the land wind, we stood towards Arthurs Seat, with the view of passing out to sea through the south channel, but the wind coming strong from the