An enquiry into M. Antoine d'Abbadie's journey to Kaffa, in the years 1843 and 1844, to discover the source of the Nile / [Charles T. Beke].

  • Charles Tilstone Beke
Date:
1850
Catalogue details

Licence: Public Domain Mark

Credit: An enquiry into M. Antoine d'Abbadie's journey to Kaffa, in the years 1843 and 1844, to discover the source of the Nile / [Charles T. Beke]. Source: Wellcome Collection.

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    a nature, that any common navigator with the most ordinary instruments is competent to make them with sufficient accuracy for all practical purposes. Consequently, there ought not to exist any room for question in those of a traveller professing to be an experienced astronomer, and using an excellent reflecting circle, or even a good sextant constructed by Gambey.^ On the occasion of his first journey to Enarea, M. d’Abbadie expressed himself thus :—My hu^in Sakka is in 8° 12' 30' North latitude, the star observed not having been corrected for aberration and nutation^ ^ Much as we had a right to expect accuracy on the part of the observer, it is difficult to refrain from smiling at this amusing pretension to scrupulous minuteness, which is useless in practice, and which—to repeat the remark of an astronomer of eminence on my mentioning it to him—is very like uspig a lower-deck gun to shoot snipes.” From my iiiahility to make the necessary corrections,” or from some other cause yet to be explained, my estimated lati¬ tude of Sakka does not altogether coincide with that observed with such unusual precision by M. d’Abbadie; for, in my map,^ I place this town in 7° 51' N., which shows a difference between us of as much as 21' 30—being 3' 30 more than the difference with respect to the latitude of Tullu Amhara. Nevertheless, I hope that eventually this difference will gradually disappear; and that for the following reason. In the account of his second journey, M. d’Abbadie, through some inexplicable^ jiegligence,. omits to mention the latitude of Sakka. But, on the other hand, he does state that the source of the Gibbe is in 7° 49' 48 N. which, while it places that spot very close to my estimated posi¬ tion of Sakka, (7° 51' N.) makes it to be as much as 22' 42, or rather more than 26 statute miles, away from that town as placed by him. We are further told that the latitude [of the source] agrees well, by even [plane ?] angles from Sakka and Goruqe, with that resulting from angles pencilled on a circumferentor;”^ and, again, that during five months,” from the “ door of [his] little hut in Sakka,” his eye rested every morning on the forest of Babia and the sources of the Enarea Gibbe.”^ ‘ The meaning of all which, if I rightly understand it, is that M. d’Abbadie was able to measure plane (?) angles with his theodolite, and to pencil corresponding angles on his circumferentor, of a spot on which, notwithstanding its distance of upwards of twenty-six miles, his eye had rested during five months. It is, however. ’ Bulletin, voL iii. p. 57. ^ Ibid. p. 56. ^ Journ. Boy. Geogr. Soc. vol. xiii. '* Athen. No. 1041, p. 1058. ® Ibid. p. 1058. « Ibid. p. 1057.
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