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"This island is almost round, and supposed to be about two ki^o in diameter. By good observation its latitude is 38° 29'; its longtUrfe 26° 33'. The bearing and making it in sailing roand is expressed u the drafts* above."
[The following is Captain Tillard'a account of the small island on the H»th-wet coast of St. Michael, within a mile of the shore, and which he named after b» own vessel.]
The eruption producing an island broke out in about thirty fathom water on the 14th of June, 1811, having been previously for two « three days preceded by repeated shocks of earthquakes, sensibly felt m the capital of the island of St. Michael, and throwing 'down several cottages and parts of the cliff next the south-west side near it* vicinity.
The first burst through the water was in three or four places about a ship's length apart, which occasionally subsided; on the 15th, the day I arrived off the island, the whole of these had become united, forming an immense column of white smoke, and occasionally throwing up black ashes from 50 to 100 feet high. On the 18th, having pioceeded over land to within one mile of it, in company with the consul; shortly after my arrival, for the first time a small peak was discovered above the surface of the water, which at every subsequent eruption increased, and this so rapidly, that in three hours, the time we remained on the cliff, it had formed itself a complete circle of cinders above water, nearly twenty feet high, on the side towards the sea; but which always broke in on the side nearest the land, after a violent explosion, when the water rushed into the crater with the greatest impetuosity.
The cliff we were standing upon was perpendicular, and about the height of the North Foreland; the volcano a short mile from the shore, ascertained by bearings from the extremities of a base of 800 feet, and since more accurately by cross bearings in the ship.
The eruptions were now so violent as to throw up the ashes as much above the level of our eye as the volcano was below it, they were thrown up in a spiral form, the first succeeded rapidly by a second, third, and fourth, each one overtopping the other, so as to form an appearance like a group of magnificent pines; aud which, as they attained their utmost altitude broke into smoke in the most fanciful forms imaginable, the most beautiful of which bore an appearance to innumerable plumes of ostrich feathers surmounting each other.
The cloud of smoke as it expanded itself in a horizontal direction to leeward, attracting by its heat the water up into it by a quantity of water spouts, formed another extraordinary feature. These eruptions were accompanied by the most vivid flashes of lightning, with a noise like I ,lContl.nued firing of cannon and musketry, and slight shocks the clfff? «' thouSh one was slro»g enough to loosen the edge of with ,„ . fift? vards from where we were standing, aud which fell
jn an amazing crash.
aving on the succeeding day proceeded to sea, and again making of these are given, but we have considered one sufficient here.
the island on the 4th of July, I found the volcano perfectly quiet, and the wind obliging me to pass pretty near it, I went, accompanied by some of the officers, to explore it more narrowly, and on our approach, from its appearance was induced to land. The form of the island is nearly circular, about a mile in circumference at its base, and its altitude about 300 feet.
On the side facing the land is an entrance into the crater nearly opon a level with the sea, and is about eighty or ninety feet diameter, from which there is a small stream running into the sea, about six yards across, and close to the waters' edge was so hot, as only to admit the hand to be dipt into it and taken instantly out again. I should conjecture that the crater is rilled from the sea at high-water.
About two boats' lengths from the beach we had seven fathoms water, and twenty-five fathoms about half a cable off.
On The Longitudes Of The Principal Maritime Points Of The Globe. By Lieut. Raper, R.N., Sec. R.A-S.
(Continued from p. 6)7.).
In the Philosophical Transactions for 1822, in a paper by Mr. Goldinghani, will be found notices of observations made at Calcutta, Coringa, Masulipatam, Bombay, and Madras.
Mr. Goldinghain obtained by Jupiter's Satellites, 5h. 21m. 5s.; by these and other observations, he finally adopted 5h. 2lm. 9-4s., or 80° 17' 21". The results of 800 lunar observations, made between 1787 and 1792, gave 80° 20' 16"or 2' 55" too great, as was then considered. These observations are given in the Madras Observatory Papers, contained in three folio volumes, at the India House.
Mr. Taylor, (astronomer at Madras,) gives
Vol. I. Madras obs. 1831, by Jup. Sat. 5h. 21m. 5-4s., or 80° 16' 21"
and by moon culminating stars 5 21 3-8, or 80 15 57
Which is adopted in the Nautical Almanac.
In Vol. II. for 1832, he gives Jup. Sat. 5b. 21m. 21-8s. or 80 20 27
and by moon culminating stars 5 20 55'C, or 80 13 01
Which however he considered as 5 or 10 seconds too small.
In a letter from the Cape, dated January the 23rd, 1840, to Captain Beaufort, Mr. Maclear gives the results of corresponding observations of moon culminating stars at Madras and the Cape, in 1834, 1835,1836, and 1837,* as follows.
* These observations are now printing in the llth vol. of the Mem. of the Royal Astronomical Society.
ENLARGED SERIES.—NO. 11.—VOL. FOR 1341. 5 E
Each result includes from two to four different stars. Only three obserrstions of the second limb occur. The result of these 70 observations is stated to be 4li. 7m. 5-6s., with a probable error of + 0'5s, Then 4h. 7m. 5-Gs. addfd to lh. 13m. 55s. (see Nautical Magazine, vol. 1839 p. 548,) gives 5b. 20m.5G^s.
Mr. Riddle has computed the longitude of Madras by comparison of similar observations made at Greenwich, Cambridge, and Edinburgh, in the same years. [Memoirs of the Royal Astronomical Society, v*lII.]
By .r)4 corresponding observations at Greenwich "50 " Cambridge
"65 " Edinburgh
If we consider these three observatories as equally well established, and then
Attach to each result the weight proportioned to the number of observations, we
obtain 5h. 20m. 55'7s., a result agreeing within Is. of that depending on the
, We shall adopt accordingly 5h. 20m. 56s., or 80° 1 i' 0''
St. George's church is 2' 21" east of the observatory, and
the flag-staff on the same meridian very nearly, or 80 16 20
From the paper quoted above, by Mr. Goldingham, we have,
Golding. 1791, place of obs. by 160 lunars 72°
by 180 do. 72
Subtracting 2' 55" from these according to the correction applied
Jnp. Sat correcting the Tables 72
D.L. Madras observatory, Ich. 16d. 7° 24' 12" 72
The mean of all these is 72° 53' 49". The place of observation, (in latitude 18° 57' 41" by 32 mer. nits, of the sun and stars,) being 3' 19" N. and 13" E. of the lighthouse, gives for the latter 72° 53' 26".
Hosb. 1S03. Flag-staffS.E. bastion of Castle, 10 obs. Jup.Sat. 72 57 40 Captain B. Hall, 1814 72 50$
Captains Elwon and Moresby in their surveys of the Red Sea, and Captain Haines in his survey of Socotra, have adopted 72° 53' 26".
In a note to Captain Washington, Captain D. Ross quotes the position of the oliservatory, connected by Lieutenant Shortreed with the general triangulation of India, in 72° 51' 15-6", as depending on Madras in 80° 16' 30" To this he states I' 186" is to be added, for the position of the church, which is the point of departure of the marine surveys, and which would accordingly be thns placed 72° 52' 34-2'».
According to this statement, the diff. long, between the church at Bombay, and the oliservatory at Madras is 7° 23' 56'', which subtracted from 80° 14' 0'' our adopted longitude, leaves for the longitude of the church 72° 50'4".
Captain D. Ross in the note just mentioned quotes also other meridian distances from Madras, which we shall annex, viz.
Hosb. D.L. Madras fl. st. 7" 21' 45"
Ileyw. D.L. do. 7 24 0
_ Horsbiirgh seems to quote this difference as 7s 23' 18", vol. 2, (183G,) page Mcintosh. D.L. do. 7° 25' 0"
Guldingh. D.L. do. 7 25 42
The mean of these is 7° 24'7", which subtracted from 80° 10' 20" gives 72° 52' 13", agreeing closely with the position above discussed as regards tfie observatory, but not the flagstaff.
In a letter at the India House, of May, 1840, Col. Everest gives the long, of the light-house 72° 51' 11*7"; stating, however, that the compulations had not undergone revision, and that the result depended partly on the measurement of the Beda base which awaited verification, Since the receipt of that letter, Mr. Walker, (the hydrographer to the H.R.I. Company,) acquaints me that the Beda base has been verified. If, therefore, we apply the diff. long, between the above and Madras <in 80° 17' 21",) or 7° 26' 9", to 80° 14' 0", we obtain for the light, house 72° 47' 51". The flag-staff, which is 1' 30'' east of the lighthouse, would, therefore, be in 72" 49' 21" ; .and the church which, with the saluting battery, is 16' west of the flag-staff, in 72° 49' 5". Since however, the position is on the point of being definitively connected with Madras, we shall not, until the result is officially given out, make any alteration in the longitude employed in the extensive marine surveys of the Persian Gulf, Coast of Arabia, and Red Sea, namely, the church, in 72° 53' 26", which for the present we adopt.
It will be proper, therefore, to bear in mind, that the longitudes referred to the church will be subject to a minus correction, which may be expected not to differ much from 4/ 21",
188. Agoada Point. Jetty.
Lt. ho. Lambton, D.L. Madras oba. G° 28' 28" 73° 45' 32"
Moresby, D.L. Bombay 0 50 4*
We adopt 73° 45' 33".
* This diff. long, applied to 73° 45' 32" gives for Bombay, (church as we suppose) 72"" 49' 2C", agreeing nearly with the position deduced.
180. Mangalore flag-slaff.
Lambton, trig, survey, 74° 50' 53". Horsburgh quoting tlio trig, survey, adopts 74° 53'.
Again, in the original list of the positions of die trig, survey, the diff. long, between Madras and this place is given at 5° 24' 45", which applied to his long, of Madras or 80° 18' 30", gives 74° 53' 45". The difference of the two longitudes 80" 18' 30", and 74° 60' 53" is 5" 27' 37".
It appears from a document of Capt. D. Ross's (at the Geographical Society,) that the flag-slaff has l-een moved one mile to the N.N.K.; hence, as we do not know precisely when this took place, we must be content to admit for the present a discrepancy, amounting however to only 22".
Moresby, D.L. Bombay 1°
Jmncs,« 1835 D.L. do. 4ch. 4d. 1
* jklaatcr of her Majesty's ship AnJiomache.
I liarc adopted 74° 5V 0", in order to preserve the correction with Boaatar •
190. Anjcnga, flag-staff.
Survey 76c 49 2S".
DX. Madras obs. 3 29 2 76* 44' 5S"
191. Calcutta. Fort William, flag-staff.
Colebrooke, Jup. Sat. compared with corresponding Greenwich efceem-
Major Hodgson, Jup. Sat. according to the Tables as corrected
■—By 91 lunar transits (Conn, des Terns. 1336)
Wurm. Astr. Nachr. No. 173, 27 eclip. Jup. Sat.
Roes, (Authorities not stated,)
Col. Everest, in a note to the Hydrographie Office
Colebrooke. D.L. Madras obs. Jup. Sat. by numerous
Hodgson. D.L. do. 9 Im. I. Sat. 32m. 25-8s.\R -
If we take the mean of Colebrooke's and Hodgson's astronomical diff. long, or 8° 4' 42", and apply it to 88° 14' 0", we obtain SS° IS' 42", which agrees nearly with the result of the lunar transits. By comparing the longitnde of Fort William, communicated by Col. Everest, with that lately employed for Madras, or 80° 17' 21", it appears that he considers the diff. long, of these places 8° 2' 56". As we conclude thai Col. Everest is the best authority on this point, we shall apply this last quantity to 80° 14', which gives Fort William 88° 16-' 56".
In assigning this position to Calcutta, we must apply a correction of about —3' to such of Captains Ross and Crawford's surveys of Aracao, ami the coast to the southward, as are referred directly to Calcutta. Should therefore the ditf. long, adopted above, between Calcutta and Madias be much altered, a corresponding alteration* must again be carried through these surveys. These changes are necessarily unavoidable, in the attempt to obtain a systematic connexion among all the places.
• It is proper to remark here, for the information of the reader, who may not have seen the Into mala in my Practice of Navigation, (published in this Magazine,)liat the statement respiting the D.L. between Bombay and Maugalore in the page of corrections is erroneous.
1 1 understood at the time I obtained these data, that the survey bad proceeded .! far as Calcutta, but that the calculations had not been fully made.
192. Diamond Harbour.
Lloyd, 8'50" (about) west of Fort William, or 81° 8' 6"
The British Queen, steam ship has sailed for Antwerp. The British and American Steam Compuny it is said, bnvc received for her the sum Of £60,000 from ibe Belgian Government. For the President the same Company, it is said, received ubovc £'70,000 from the Underwriters. The losses sustained by the Company since its'establishment are supposed not to be less tlian £80 000, "or more than £100,000.—Liverpool Albion, Sept, 6. So much for thv Lcvjatliiins,