[130]All the people assured me that the preceding year the rain-fall about this time of the year had been much more considerable. They generally reckon four rainy days in March and three in April, and call this season the Nisán.

APPENDIX VIII.

A FEW REMARKS WITH REGARD TO THE MAPS.

By Dr. A. Petermann.

It was originally intended to compose a full memoir on the subject of the construction of the maps showing Dr. Barth’s travels and researches; but the preparation of the drawings themselves has, up to the last moment, occupied so much time that, in order not still further to delay the publication of these volumes, an apology only for a memoir can be offered. Besides, all the native information and the itineraries, which form the substance of so considerable a portion of the two general maps, have been given at full length in the Appendices to the five volumes. It was also felt that, better than all the most elaborate disquisitions and discussions that could be advanced in such a memoir, will be the test applied to the maps by the Niger Expeditions, which for a period of five years are to proceed both up the Kwára and the Bénuwé by means of steamboats, commanded by experienced naval officers, who will set at rest the true positions of such of Dr. Barth’s points as they may be able to reach. The first expedition which was sent out to follow up Dr. Barth’s discoveries, namely the expedition up the Bénuwé in 1854, commanded by Dr. Baikie, did not, it is true, reach the point where Dr. Barth crossed that river in 1851[131]; but a second expedition will, no doubt, penetrate further. Meanwhile, the present expedition up the Kwára will, it is hoped, reach Say during the present year, and, by fixing the position of that place accurately, will offer an important point of comparison with the results of Dr. Barth’s labours.

After the foregoing remarks, it must at once be distinctly stated that Dr. Barth himself has made no astronomical observations either of latitude or longitude. The best established of Dr. Vogel’s positions, therefore, were made use of in constructing the maps, and consequently they form the basis of most of the routes connected with Múrzuk, Kúkawa, Zínder, and Yákoba. Beyond these points the routes were almost wholly laid down from dead reckoning, with the exception of those from Tripoli to Múrzuk, viâ Mizda, and from Múrzuk to Ghát and Aïr, where Dr. Overweg’s observations of latitude were made available, as well as the only observation of longitude that could be made out from the fragmentary and torn remains of his papers, namely, that of the island of Belárigo in Lake Tsád.[132] It will be seen, therefore, that by far the greater portion of the countries over which Dr. Barth’s labours extend, was laid down either from dead reckoning or from computations of native routes and native information. Thus the whole route from Zínder to Timbúktu, for example, a distance by Dr. Barth’s travelling lines of upwards of 1200 English miles, had to be laid down solely from dead reckoning taken from a very accurately kept journal; and the magnetic variation had to be guessed at. Yet, despite of these shortcomings, the writer hopes that in the construction of these maps, in several of which he was greatly assisted by the original maps laid down by the traveller himself, he has not departed very widely from the truth; and he looks confidently forward to their being tested by the Niger expeditions.

A great deal has been said of late on astronomical observations in connection with African exploration, and it has—in some instances—been represented as if only those travels and explorations which were based on such observations were valuable, while all others were of no value. Assertions made thus indiscriminately are most objectionable, as a careful noting of the bearings and distances of each day’s journey, such as Dr. Barth has made, is far preferable to many astronomical observations which cannot be implicitly relied on; it is only the accurate astronomical observations which deserve to be regarded as well established points in a traveller’s route. In our own case we could adduce many striking instances of the uncertainty of occasional observations. Thus, although Dr. Vogel was an astronomer by profession, fully competent to make observations with care and accuracy; yet, in the construction of Dr. Barth’s own routes, south, south-east, and east from Kúkawa to Ádamáwa, Músgu, and Bagírmi, we saw good reason to reject all Dr. Vogel’s positions bearing upon these routes, as Ujé, Díkowa, Dilhé, Wáza, Kadé (Ádishén), &c. &c., and to prefer simply Dr. Barth’s itineraries of dead reckoning.

Note by Dr. Barth.—In constructing the western sheet of the general maps, no notice has been taken of the fact of Major Laing having entered the desert of Tanezrúfet in 23° 56′ N. (Quarterly Review, 1828, vol. xxxviii. p. 101.) But we do not know whether Laing proceeded by way of Inzíze or by some other route. It is, however, not improbable that Aúlef, the starting point of those routes, lies about twenty miles further south.

The identification of Bot-hadíye with Bakel on the Senegal, is not quite certain; but at all events it is a place at no great distance to the N.W. of it.

[131]The information Dr. Barth was able to collect with reference to the lower part of the Bénuwé, as far as subsequently surveyed by Dr. Baikie, was rather meagre; yet even with regard to those few data, provisionally as they were laid down from Dr. Barth’s original map in A. Petermann’s “Account of the progress of the Expedition to Central Africa, London, 1854,” Dr. Baikie acknowledges the service that map proved to him, and records his testimony both as to the amount and general correctness of the information it contains. (See Dr. Baikie’s “Narrative of an Exploring Voyage in 1854,” p. 446.)

[132]The cardinal points of the maps where astronomical observations had been made by Dr. Vogel, besides Tripoli, are the following:

Longitude E. Latitude N.
Sókna 15° 48′ 30″ 29° 4′ 4″
Múrzuk 14 10 15 25 55 16
Kúkawa 13 24 0 12 55 14
Yákoba 9 31 45 10 20 10
Zária 7 23 10 11 4 46
Bebéji 8 6 25 11 35 30
Zínder 9 2 45 13 47 6

Besides, Dr. Vogel has made astronomical observations at the following places: Bení Ulíd, Enfád, Bonjem, Godfah, Óm el ʿAbíd, Gurméda (wrong name), Sebhá, Bimbéja, Bahr el dúd, Óm el mé, Lake Mandra, Jerma, Ghodwa, Mʿafún, Mastúta, Gatrón, Tejerri, El Áhmar, Má-faras, Jehaye, Ashenúmma, Shemúttero, Bilma, Zau kurá, Ágadem, Bélkashi farri, Kufle, Kibbu, first outlying fresh-water basin, north-western end of the Tsád, Ngégimi, Bárruwa, Yó, Morá, Ujé (Mábani), Máshena, Múniyó (Búne), Zínder, Gújeba, Gebbeh, Gombe, Dan Hajji, Múri, Tindang, Díkowa, Delhé, Wáza, Ádishén (Kadé, residence of Ádishén), frontier of territory of Ádishén, north end of Túburi Lake, Túburi village, mountain on west side of lake. (See the Journal and the Proceedings of the Royal Geographical Society of 1854-1858. But in the Journal, vol. xxv. p. 242., there is a misprint, the latitude of Kúkawa being given as 12° 15′ 14″.)

Mr. Overweg’s latitudes, besides his observation at Belárigo (14° 50′ 0″ long., 13° 26′ 37″ lat.), relate to the following places: Mizda, Taboníeh, El Hasi, Wádí Ajúnjer, Falésselez, Aísala, Tin-téllust, Ámfisás, island of Gúria in the Tsád, and on his route to the Músgu country, Yédi, Marte, Alla, Del-hé, Zógoma, Mása, five other intermediate stations, and three observations in the district of Wúlia. (See Petermann’s account, p. 15.)

INDEX.