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shoal, and bears, from the wind- open to the northward of the north mill to the southward of Point point of Corfu.” Lefchimo, N. by W. W.; from Directions for the North Chanthe S. E. extremity of the island nel by night." In coming for this of Corfu, N. N. W. 4 W.; from channel, when you make out the Black Island, N. 62 deg. W., or light, steer straight for it; and I N. W. by W. 1 W., distance eight would recommend all ships with a miles ; and from Corfu lighthouse, leading wind, to pass between the S. 35 deg. 30 min., E. or S. E. light and island of Corfu, to avoid

S. nearly, distance 104 miles. the Boat rock, which is not larger

The third is also a single light (above water) than a small boat, at the east side of the island of bottom up, and has a shelving reef Payo, upon a small island at the stretching off from it, N. W. N., entrance of Port Gayo. The light about 120 fathoms, with from two is upon a tower, which bears from to seven fathoms water upon it. the south end of Payo shoal W. This channel, between the light 5 deg. S. or W. į S. nearly ; from and Corfu, is six-tenths of a mile the north end of ditto, W. 11 deg. broad, with 30 fathoms water in S. or W. by S. nearly. The centre the middle, and steep-to on both of the shoal is 14 miles distant sides. After passing the light, from the light, and the S. E. point steer S. E. by E., or E. S. E., bring of Corfu bears from it N. by W. the light to bear N. W. { N., and

W.; S. E. extremity of Anti keeping it on that bearing, will Payo, S. E. E.; Black Island, lead you clear of the Sarpe rock, N. a little easterly ; N. E. end of which lies just to the southward Payo, N. W. a little westerly, of the N. E. point of Corfu. This This light is particularly useful to is a very dangerous shoal by night, the small coasting vessels running it being nearly level with the water, for Port Gayo (or what is more and so steep-to, that the lead is commonly called Payo harbour) in of no use. When you get sight of bad weather, as also to all vessels Corfu light, bring it to bear S. by passing through the south channel. W., and by keeping it so, it will

“ The fourth is a single light on lead you clear of all danger, and the rock Tignoso, in the entrance right up to the east end of the of the north channel. It is a most island of Vido, páss 1 mile to the valuable light to vessels passing eastward of that island, then steer through this channel to guide them in, and anchor any where betweev clear of the Boat and Sarpe rocks. the island and town of Corfu. The N. E. point of Corfu Island “Ships passing through the north bears from it S. } W. nearly; channel with variable or a beatCorfu light shut in behind this ing wind, will find it better to pass point; the Sarpe rock bears from to the northward of the light, and it S.; S. W. point of Albanian then it must not be brought to coast, S. by E.; Boat rock, E. the westward of S. W. by W. 1 nearly half a mile distant, with 16 W. until you are a good mile to and 20 fathoms water between the eastward of it (to avoid the them. S. W. extremity of the Boat rock), or until Corfu light land about cape Linguetta N. W. bears S. by W.: when the north N.; and the north point of the channel light bears W. a little island Melue, W. by N.N. Just southerly, it is on with the Boat rock; and when the light bears W. side of Corfu as far as the light {N., you are well to the southward vessel, pass half a mile to the eastof the Boatrock. In beating through ward of the light, and generally this channel, keep on the Albanian by this time you will see Corfu shore, it being all bold; and stand light; bring it to bear N. W. I N., very little more than half channel or N. W. , N., then steer for it; over to the westward until you pass half a mile to the eastward of are well to the southward of the it to clear Old Citadel Point, then Sarpe rock.

steer in and anchor as before. “Vessels going to the northward “Ships coming from the westwill have no difficulty in observe ward for the south channel, between ing these directions in a contrary the island of Payo and cape Bianco, order."

should keep midchannel, or nearer Directions for navigating the to the former than the latter ; South channel." In coming from steer in N. E. J N., or N. E { E., the southward of Payo, for the and after opening Payo light, consouth channel, with southerly or tinue on the same course until south-westerly winds, you may the light bears S. { E., then propass between Payo shoal and ceed as above. light, or to the eastward of the "In coming from the southward, shoal, at pleasure. To pass be- it will most generally be advisable tween the shoal and light, give to pass to the eastward of Payo Anti-Payo a good birth, and as shoal ; then keep in midchannel, soon as you open the light, bring or rather the Albanian coast on it to bear N. W., or N. W. { W., board, it being all bold, and may then steer for it, and keeping it be approached within half a mile. on either of these bearings will lead When Payo light bears W. by S. you to the westward of the shoal ; { S., you are to the northward of pass half a mile to the eastward the shoal. When working through of the light, and when it bears W. the south channel, while well to by S. 1 S., you are to the north- the southward of Lefchino light, ward of the shoal, and may keep you may stand to the westward away N. by W. & W., or N. by W. until the light bears N. W.; but When Payo light bears S. į E., when within a mile of it, it must keep it on that bearing, and it be brought to the northward of will lead you well to the eastward N. W. by W. į W., to avoid the of the buoy on the S. W. extre- N. E. elbow of the shoal. The mity of cape Bianco shoal. When Albanian coast is all clear and bold the cape bears W. by S. { S., or to the southward of the light Black Island N. E. by E., you will vessel ; but after getting abreast of be to the northward of the buoy, her, you must not stand within and may then steer N. W., or N. two miles of it, to keep clear of W. by N., according to the wind. the Bacchante shoal. The Corfu You will then very soon get sight side is then all clear, and you may of Lefchimo light, which must stand well over towards it. not be brought to the northward “All the above are to the nearest of N. W. W. To keep you quarter of a point to the true bearclear of Lefchimo shoal, which is ings, or according to the poles of a continuation of the one off cape the world. Bianco, and runs along the east “The bearings and distances cons tained in the preceding directions that place, and it was then found were taken by W. Smith, esq., to be running with the astonishing master of his majesty's ship Naiad. rapidity of 99 miles in 24 hours.

(Signed) W. ROBINSON.” On the 10th Sept., at 10 a. m., “ Inspector-General of Ionian while proceeding in

in the full Ports and Coasts.

strength of the current, exceeding Corfu, April 1, 1825.”

four knots an hour, a sudden and Currents of the Ocean. "In very great discolouration of the the voyage between Cape Mount water a-head, was announced from and Cape Three Points, captain the mast-head: the ship being in Sabine says that the Pheasant's 50 8' north latitude, and 5028' progress appears to have been west longitude (both by observaaccelerated 180 miles by the cur- tion), it was evident that the rent, which, in the season when discoloured water could be no other the south-west winds prevail on than the stream of the Amazons, this part of the coast of Western pursuing its original impulse at 10 Africa, runs with considerable less than 300 miles from the mouth velocity in the direction of the land of the river, its waters not being round Cape Palmas, to the eastern yet mingled with those of the parts of the gulf of Guinea. In ocean, of greater specific gravity, the passage between the river on the surface of which it had purGaboon and Ascension, being a

sued its course. It was running distance of 1,400 geographical about 68 miles in 24 hours.”miles, the Pheasant was aided by Capt. S. continues, “ On a general the current above 300 miles in view of the currents which have the direction of her course. been thus particularized, on the

*** “But the more important Pheasant's progress, in her voyage distinction, both in amount and in commencing at Sierra Leone and utility in navigation, is between terminating at New York, it may the waters of the Equatorial and be seen that she was indebted to the Guinea currents. These ex- their aid on the balance of the hibit the remarkable phenomenon whole account, and in the direction of parallel streams, in contact with of her course from port to port, each other, flowing with great not less than 1,600 geographical velocity in opposite directions, and miles, the whole distance being having a difference of temperature under 9,000 miles; affording a amounting to ten or twelve degrees. very striking exemplification of the Their course continues to run importance of a correct knowledge parallel to each other, and to the of the currents of the ocean, to land, for above 1,000 miles; and, persons engaged in its navigaaccording as a vessel, wishing to tion; and consequently of the proceed along the coast in either value of the information, in direction, is placed in the one or the acquisition and arrangement the other current, will her course of which major Rennell has passed be aided from 40 to 50 miles a-day, the latter years of his most useful or retarded to the same amount. life. The publication of the charts On the day after the Pheasant of the currents in the most fresailed from Maranham, she entered quented parts of the occan, which the current, the full strength of he has prepared with his accustomwhich she had quitted to go to ed and well-known indefatigable Vol. LXVII.

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assiduity, and strict adherence to given on the 22nd is only approxithe evidence of facts, (as soon as mate ; it will, however, be amply he shall deem them sufficiently sufficient to enable observers to complete), will be a most impor- find it. It is visible in a night glass. tant service rendered to practical navigation."

The Second Comet, or the Comet Meteor.-Guelderland :-" The

of short period. rains we had in August have con

August 21, 1825. tributed much to the improvement Right Ascension 7h 53 29.31"

At 1h 39' sidereal time. of the crops in general, especially Declination 28° 40' 24.45" N. after the great and intolerable heat

August 22, 1825. of which I gave you an account in At 1h 39' sidereal time. one of my former letters. In the Right Ascension 8h 1' 29.16" latter end of August, a singular

Declination 28° 9 56.78 N. aerial phenomenon took place at

This Comet also has no appear11 o'clock in the evening, viz.-- ance of tail; its observed place very considerable blue light was differs so little with that given in seen, which gave a most extra- Eicke's Ephemeris, that by placing ordinary appearance to all sur- the instrument according to the rounding objects ; so much so, that data there given, the Comet will be notwithstanding, it á full easily found. It is not visible in moon, and fine clear weather, it so the night glass, yet it is much more frightened the servants, who were distinct than the preceding Comet. standing in the garden behind our Passy, near Paris, Aug. 23, 1825. house, that one of them came Aurora Borealis. A late running into our room, in the number of the Edinburgh Philogreatest state of alarm, to mention sophical Journal contains a memoir the circumstance. The same ap- by professor Hansteen, in which pearance was noticed at the very that eminent naturalist has sketched moment through the whole coun- out a very bold and plausible try, which proves that the substance theory of the Aurora Borealis. The or combustible fluid which emitted connexion of that phenomenon it must have been at a great eleva- with magnetism has been long tion."

remarked, and is further confirmed Two Comets. The following by the observations of the profesare particulars of_two Comets at He considers the Aurora present visible in Europe : Borealis as a luminous ring surThe First Comet.

rounding the magnetical pole, with

a radius varying from 20 deg. to Observatory, Passy, Aug. 21, 1825. 40 deg., and at the height of about

Sidereal time at Passy.
Rt. Ascen. 4h 15' 2.96" at 23h 36' 18''

one hundred miles above the surDeclina. 21° 40 50.07 N. at 23 43 43 face of the earth. It is formed, August 22, 1825.

he thinks, by luminous columns

shooting upward from the earth's *Right Ascension 4h 14 49"

surface, in a direction parallel to Declination 21° 26

N.

the inclination of the needle, and This Comet has no visible tail, to the direction of the earth's is very faint, and has the appear- magnetism : these columns render ance of a Nebula.. The place on the atmosphere opaque while they the 21st is tolerably exact ; that pass through it, and only become

sor.

At 1h 1' 36" sidereal time.

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luminous after they pass beyond it. the standard during Dr. Tiarks' From the outer or convex side of survey to ascertain the longitude the ring beams dart forth in a of Madeira in July and August, direction nearly perpendicular to 1822; and its accuracy during the the arch, and ascend towards the time it was under his care induced zenith ; and if they are so long as him to take the longitude of Mato pass it towards the south, they deira from it. Dr. Tiarks takes collect in the south in a sort of the mean of the whole 16 chronocorona or glory, which is situated meters employed on the occasion, in that point of the heavens to by interpolation ; and the standard which the south pole of the needle gives the same result as the whole points. Professor Hansteen finds 16, within two hundredths of a that the observations made respect- second. It appears that through ing the Northern Aurora are well the means of these chronometers, explained by this hypothesis ; and Dr. Tiarks has been enabled to he has collected facts to show that discover a considerable error in the a similar ring exists around the longitude of Madeira (as laid down southern magnetic pole situated in by a former survey), and to find New Holland, the northern being out where the errors lay. He was in North America. He infers employed by the Admiralty, at the further, though the stock of obser- recommendation of the board of vations is rather deficient, that Longitude, in 1823, to find, by the similar luminous rings exist above use of chronometers, the differences the two extremities of the secondary of longitude between Dover and magnetic axis, in Siberia, and in Falmouth, and Portsmouth and Tierra del Fuego.

Falmouth; and for that purpose he Chronometers.—The official re- was furnished with 29 chronoport from the board of Longitude meters from the royal observatory, of last year's trial of chronometers including all that were on trial for has been published. The annual the prize. On this survey, he has prize of 300l. has been awarded to discovered an error in the longiMr. W. Widinham, of East-street, tude of these important stations, as Red-Lion-square, for the best chro- laid down by former surveys, in nometer, it having varied only 1 consequence of the accurate rate of second and 80 hundredths of a going of these chronometers. He second on its mean daily rate during has thus been enabled to establish the 12 months. The prize of 2001. the following results :-Longitude has been awarded to Mr. J. M. of Dover station, 5 min. 17 sec. French, of the Royal Exchange, 54. E. ; Portsmouth Observatory, for the second best chronometer, 4 min. 24 sec. 77. W.; Pendennis: his having varied 1 second and 85 Castle, 20 min. 10 sec. 85. ; Mahundredths of a second during the deira, 1h. 7 min. 39 sec. 08. On 12 months ; 85 hundredths of a this occasion, also, it appears that second during the last 9 months; Mr. French's chronometer was the and 45 hundredths of a second standard. The former survey had during the last six months, on its placed the longitude of the two mean daily rate. Mr. French's latter places about 4 seconds less. chronometer, No. 720, was made to the westward.

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