Page images

as Mount Dhaibun. It was seen under an angle of 5° 4' 21", and ascertained to be distant 354 g. m. The elevation, calculated from this measure, is 20,140 feet above the station from which the altitude was taken, and which is itself more than 4,500 feet above the level of the sea, as concluded from barometrical observations. Another, seen under a similar angle, 5° 3′ 58′′, but less distant by four miles, exceeds the elevation of the station by 17,819 feet. Both these mountains are but little to the eastward of north from Cat'hmandu. The following are as little north of east, viz. one nearly in the position of Cala-bhairava, distant 59 g. m., with an altitude of 2° 48′ 6′′, and consequently 20,025 feet high another in its vicinity with an angle of 3° 23′ 6′′, distant 48 g. m., and elevated 18,452 feet: and a third, as much more remote, being 68 g. m., with an altitude of 2° 7′ 21′′, and a consequent elevation of 18,662 feet above Cat'hmandu.

All these mountains are perceivable from Patna: the first, or the supposed Dhaibun, at a distance of 162 g. m., and Calabhairava, or the mountains in its vicinity at that of 153, 150, and 145 g. m. These are the nearest of the Himalaya which are visible from that city. The most remote are seen in the N. E. quarter at the prodigious distance of 195 g. m., ascertained by their position, which is determined by bearings taken by Col. Crawford from stations approaching within 100 miles of their site.

Mount Dhaibun, or at least the peak which was indicated to Col. Crawford under that name, and which is not surpassed by any of the points measured from Cat'hmandu, was viewed by Gen. Kirkpatrick, if indeed it be the same mountain, from a position 10 miles nearer to it, on Mount Bhirbandi: and his animated description of the sublime prospect contains presumptive evidence that the remoter glacieres of the Himalaya are still more elevated; for he speaks of a neighbouring mountain not less stupendous, yet surpassed by one of the pyramidical peaks of the snowy chain seen peeping over its towering summit. It may readily be credited that the more accessible mountains which approach Cat'hmandu, as Jibjibia, Dhaibun, and Dhuncha, may be inferior in heighth to the abrupter peaks in the chain of the Himalaya.

Among the loftiest in that chain is one distinguished by the name of Dhawala-giri, or the White Mountain, situated, as it is understood, near the source of the Gandhac river, called in its earlier course Salagrami, from the schistous stones containing remains or traces of ammonites found there in the bed of the river, and thence carried to all parts of India, where they are worshipped under the name of Salagrama, the spiral retreats of antediluvian molluscas being taken by the superstitious Hindu for visible traces of Vishnu.

A high peak, among the most conspicuous of those which are seen from the plains of Gorakhpur, and on that account selected VOL. XI. N° I.

by Mr. Webb for a measurement, conducted by means of observations taken at different stations in that province, was pointed out to him as recognized by the mountaineers to be Dholagir (Dhawala-giri). Mr. Webb took the bearings from four stations, and altitudes from three; and the particulars of his observations are as follow:

At station A, situated near Khatur, bearing of the snowy peak P, corrected for magnetic variation, and error of adjustment, by an azimuth observed at the same time


N. 30° 12′ E. 2 48.

At station B, Nowa-newada on the Rapti:
Bearing of P

N. 49 30 E.

At station C, two furlongs W. of Sengaon:

Bearing of P

[blocks in formation]


2 19

At station D, two furlongs W. of Bhopetpur:

Bearing of P

[blocks in formation]


1 22

B bears from A by the survey W. 2° 5' N. distant = 43·4 B. m.

D bears from A

.W.7 5 N.


73 5 B. m. The bearing of C from A is not used, the side AC measuring

[merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][merged small]

From these data Mr. Webb computes the distance of the peak P from the stations A, C, and D, at the numbers undermentioned, viz.: from the station A, by the triangle AP B, 896; and by the triangle AP D, 89.1: mean of both computations, 89.35 miles, or 471,768 feet. From the station D, by the last triangle, 135.9; and by CPD, 136·8: mean of both, 136.35 miles, or 719-928 feet. From C, by the last of these triangles, 1034; and by CPB, 102-3: mean of both, 102.85 miles, or 543,048 feet. He remarks that several other bearings of the same peak were taken from different stations; and that, by laying off the rhumb-lines of bearing on the map, they intersect at very inconsiderable distances from the position of the peak, as deduced from those which were selected for calculation.

Let us proceed to compute the height of Dhawalagiri (vulg. Dholagir) with the foregoing measures of distance and the observed altitudes.

At the station A we have the distance 471,768 feet, 77-85 geogr. miles,* or in a parts of a circle 1° 17′ 51′′; the chord of

The geographic mile, or 60th part of a degree of a great circle, is here taken at 6060 feet.

of which, in feet, is 471,758. The altitude observed being 2° 48′, and the refraction being taken at of the intercepted arc, the angles are S = 3° 20′ 26′′ 15′′ and P = 86° 0′ 38′′ 15′′”, with the side S B = 471,758; whence we have the side BP, or height of the mountain = 27,558 feet.

By a similar calculation of the altitude of the same mountain, observed from the stations C and D, viz. 2° 19′ and 1° 22′, or, corrected for refraction, 2° 11' 32" and 1° 12' 6", with the distances above found, which in parts of a circle are 1° 29′ 36′′ 36′′" and 1° 58′ 48′′, and, reduced to the chords of the arcs in feet, 543,031 and 719,893, the height comes out 27,900 and 27,573; or, on a mean of the three, 27,677 feet above the plains of Gorakhpur; and reckoning these to be 400 feet above the mouth of the Ganges, as may be inferred from the descent of the stream of rivers, the whole height is more than 28,000 feet above the level of the sea.

The following table exhibits a comparison of this result with other computations made on different rates of refraction:

[merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors]

It is apparent, from inspection, that the observations at the stations A and D agree best; and, if that computation be nearest the truth wherein the extreme differences are the least, the conclusion will be that the height is about 27,550 feet; such being the elevation deduced from the mean of observations calculated according to middle refraction.

The limit of error arising from refraction must be taken at less than 850 feet, as the observations at A and C coincide for the height of 26,690 feet, of the contained arc being allowed for refraction, and those at C and D for an elevation of 28,290 feet,

being allowed; while those at A and D do so for the mean altitude of 27,565 feet, refraction being taken at the middle rate of; and a larger allowance than of the intercepted arc (which would exceed mean celestial refraction for like altitudes) cannot be requisite without very wide disagreements in observations made on different days, which would mark extraordinary réfraction; but this is not the case with those in question.

The limits of error in respect of the observations themselves, whether for the distance or for the altitude, are more confined, since the uncertainty in the distance, amounting to of a mile in one instance, and a mile in the rest, induces uncertainty in the computed elevation to no greater extent than 76 or 99 feet for the nearer stations, and 180 feet for the most remote. An

[ocr errors]

error of a whole minute in an observation of altitude affects the consequent calculation in the proportion of about 200 feet for the more distant station, and 130 to 150 feet for the nearer. But the instrument which was used should with due care give angles true within that quantity; and the observer was enjoined to take the angles to the nearest minute.*

It would be an extreme supposition that the errors have in every instance been the highest possible, and on the side of excess. Assuming, however, that they are so, the elevation as observed from the two nearest stations is not reduced below 26,457 feet and 26,467 feet, or, on the mean of both, 26,462 feet above the plains of Gorakhpur.

We may safely, then, pronounce that the elevation of Dhawalagiri, the white mountain of the Indian Alps,† exceeds 26,862 feet above the level of the sea; and this determination of its height, taken on the lowest computation of a geometrical measurement, is powerfully corroborated by the measurement of an inferior, though yet very lofty mountain, observed from stations in Rohilkhand.



I. Philosophical Transactions for the Year 1817, Part II.
THIS part contains the following papers:

Description of a Thermometrical Barometer for measuring Altitudes. By the Rev. Francis John Hyde Wollaston, B.D. F.R.S.

Observations on the Analogy which subsists between the Calculus of Functions and other Branches of Analysis. Charles Babbage, Esq. M.A. F.R.S.


Of the Construction of Logarithmic Tables. By Thomas Knight, Esq. Communicated by Taylor Combe, Esq. Sec. R.S. Two general Propositions in the Method of Differences. By the Same.

Note respecting the Demonstration of the Binomial Theorem inserted in the last Volume of the Philosophical Transactions. By the Same.

On the Passage of the Ovum from the Ovarium to the Uterus in Women. By Sir Everard Home, Bart. V.P.R.S.

Some farther Observations on the Use of Colchicum Autumnale in Gout. By the Same.

*The writer of this was acquainted with the instrument, and knew the degree of precision which it comports.

+ Sans Dhawala (white), Giri (mountain). It is the Mont Blanc of the Himalaya.

Upon the Extent of the Expansion and Contraction of Timber in different Directions relative to the Position of the Medulla of the Tree. By Thomas Andrew Knight, Esq. F.R.S. In a Letter addressed to the Right Hon. Sir Joseph Banks, Bart, G.C.B. P.R.S.

Observations on the Temperature of the Ocean and Atmosphere, and on the Density of Sea Water, made during a Voyage to Ceylon. In a Letter to Sir Humphry Davy, LL.D. F.R.S. By John Davy, M.D. F.R.S.

Observations on the Genus Ocythoë of Rafinesque, with a Description of a new Species. By William Elford Leach, M.D, F.R.S.

The distinguishing Characters between the Ova of the Sepia and those of the Vermes Testacea that live in Water, explained, By Sir Everard Home, Bart, V.P.R.S.

Astronomical Observations and Experiments tending to investigate the local Arrangement of the Celestial Bodies in Space, and to determine the Extent and Condition of the Milky Way By Sir William Herschel, Knt. Guelp, LL.D. F.R.S.

Some Account of the Nests of the Java Swallow, and of the Glands that secrete the Mucus of which they are composed, By Sir Everard Home. Bart. V.P.R.S.

Observations on the Hirudo Complanata and Hirudo Stagnalis, now formed into a distinct Genus under the Name Glossopora By Dr. Johnson, of Bristol. Communicated by Sir Everard Home, Bart. V.P.R.S.

Observations on the Gastric Glands of the Human Stomach, and the Contraction which takes place in that Viscus. By Sir Everard Home, Bart. V.P.R.S.

On the Parallax of the Fixed Stars. By John Pond, Esq, Astronomer Royal.

In the history of the meetings of the Royal Society a general account has been given of these papers, but many of them are of so much importance as to require a more detailed analysis, Among these we may include Mr. Wollaston's description of his thermometrical barometer.

It has been long known that the temperature at which water boils is diminished in proportion to the diminution of the weight of the atmosphere; and this principle had been pointed out by Fahrenheit, and more lately by Cavallo, as a means that might be employed for measuring altitudes. Mr. Wollaston has contrived an apparatus by which this may be accomplished, even with more accuracy and convenience than the common barometer. The two great objects were, first, that very small portions of heat might be rendered perceptible; and, secondly, that the instrument should be portable Both these objects are attained by having the thermometer with a large bulb and a very

* Annals, ix. 323, 393, 468; x. 54, 139,

« PreviousContinue »