APPENDIX I

A LIST OF THE ASTRONOMICALLY DETERMINED POINTS IN AIR

The positions given in the following table have been collected from the record of the proceedings of the Foureau-Lamy Mission, from the list given on the second sheet of the “Carte de l’Air” prepared by the Mission Cortier and others on a scale of 1/500,000, and from the observations by the author. Two positions given in Lieut. Jean’s Les Touareg du Sud-Est are also included. The French longitudes have been converted into longitudes east of Greenwich by the addition 2° 20′ 14″.

The author’s observations were carried out with a three-inch transit theodolite by Cary and Porter, and were in all cases stellar sights. The latitudes were in all cases determined from pairs of north and south circum-meridian stars, or from altitudes of Polaris and one south star. The longitudes were determined by calculations based on local mean time derived from pairs of east and west stars, and chronometric differences from points which had previously been determined by French travellers. Where the author’s longitudes for points previously determined by French observers are also given, they are the result of chronometric differences from other points previously or successively visited. The author, however, has not used his own longitudes for determining intermediate points when French observations were available, and his co-ordinates in these instances are only reproduced for purposes of comparison.

The data for the Foureau-Lamy observations are described in the record of the proceedings of the expedition. The source of the positions given on the Cortier map is not stated. The data for Colonel Tilho’s positions are in the record of the delimitation of the northern boundary of Nigeria. The author’s computations are in the records of the Royal Geographical Society in London, where are also the original route reports and prismatic compass traverses made throughout the journey.

Where possible the author’s chronometric differences were checked by opening and closing a series of observations on points previously fixed by French observers. In one unfortunate case, however, the author’s watches stopped as a result of his camels going astray and the series was consequently broken. His watches again stopped at Auderas, where, however, he stayed a sufficient length of time to re-rate them. At this place a number of local mean time observations were taken over a long period.

The author’s longitude observations were carried out as follows:

Series A opened at Fanisau camp near Kano from a position supplied by the Survey school—closed at Tessawa— Dan Kaba (unreliable), intermediate position.

Series B opened at Tessawa—not closed: Urufan-Gangara-Tanut, intermediate positions.

Series C not opened—closed at T’in Wana: Termit—Teskar-Guliski, intermediate positions.

Series D opened at T’in Wana—closed at Auderas.

Series E opened at Auderas—watches rated—closed at Auderas.

Series F opened at Auderas—closed at Auderas: Abarakan-Teginjir-Telia-Teloas, intermediate positions.

Series G opened at Auderas—closed at Auderas: Aggata-Assode-Afis-Iferuan, intermediate positions.

The author’s meteorological record, which was kept for nine months, has not been reproduced. It consists of daily maximum and minimum, actual (twice daily), and wet and dry bulb temperatures; aneroid readings; wind and rainfall, and sunset and sunrise notes. It is at any student’s disposal to consult.

The following abbreviations are used in the ensuing table:

F—Foureau; Ch—Chambrun (see Record of Foureau-Lamy expedition); R—Rodd; T—Tilho; C—Cortier’s Map of Air; J—Jean’s Touareg du Sud-Est.

Place. Area. Latitude, north. Longitude (east of Greenwich). Authority.

° ′ ″ ° ′ ″

Dan Kaba[433] Nigeria 13-12-40 7-44-30 R

Tessawa Tessawa 13-45-20·5 7-59-12·6 T

13-45-50 7-59-15 R

Urufan Tessawa 14-04-50 8-06-25 R

Gangara Damergu 14-36-30 8-27-32 F

14-36-42 — Ch

14-36-50 8-25-40 R

Tanut[434] Damergu 14-58-20 8-47-50 R

Guliski Damergu 15-00-50 9-06-20 R

Teshkar Elakkos 15-07-40 10-35-10 R

Termit Eastern Desert 16-04-10 11-04-50 R

Abellama Tegama-Azawagh 16-16-32 7-47-19 C

Marandet Tegama-Azawagh 16-22-20 7-24-14 C

Ain Irhayen Tegama-Azawagh 16-26-40 7-55-22 C

Tabzagur Tegama-Azawagh 16-36-57 7-08-17 C

Tin Wana (T’in-Nouana) S. Air 16-42-32 8-25-19 C

16-42-55 8-25-15 R

In Gall S.W. Air 16-47-08 6-54-15 C

Tebehic S. Air 16-47-32 8-21-14 C

Eghalgawen S. Air 16-48-21 8-31-19 C

Agades (Post) S. Air 16-59-19 7-57-15 C

„ (T’in Shaman[435]) S. Air 16-59-02 (8-24-18) J

Tin Dawin S. Air 17-00-07 8-26-19 C

Tin Taboraq S. Air 17-01-50 8-08-19 C

Tagidda N’Adrar W. Air 17-04-13 7-22-21 C

Anu Areran W. Air 17-15-27 7-43-20 C

Fagoshia W. Air 17-16-01 6-57-17 C

Tafadek S. Air 17-23-32 7-55-19 C

Tagidda N’T’isemt W. Air 17-25-38 6-34-33 C

Tinien S. Air 17-26-54 8-09-02 F

17-26-24 — Ch

Idikel W. Air 17-29-42 7-37-23 C

Teloas-Tabello E. Air 17-34-40 8-49-30 R

Egeruen S.W. Air 17-35-15 7-54-22 C

Auderas[436] C. Air 17-37-50 8-19-00 R

17-38-00 8-18-14 F

17-37-48 8-19-30 (C)

Telia E. Air 17-47-30 8-49-20 R

In Kakkan W. Air 17-49-22 7-48-23 C

In Abbagarit Western Desert 17-53-47 5-59-15 C

Tamet Tedderet Western Desert 17-54-04 6-36-18 C

Anu n’Ageruf W. Air 17-54-46 7-24-22 C

Aureran C. Air 17-56-54 8-23-17 F

17-56-42 — Ch

Teginjir C. Air 17-59-20 — R

Abarakan C. Air 18-03-30 8-39-20 R

Aggata C. Air 18-09-00 8-26-40 R

Ufa Atikin W. Air 18-09-26 7-12-21 C

In Allaram Western Desert 18-16-12 6-15-19 C

Tamadalt Tan Ataram W. Air 18-16-23 7-49-18 C

Afasto W. Air 18-17-08 7-17-22 C

Zilalet W. Air 18-23-19 7-51-21 C

Assode C. Air 18-27-00 8-26-50 R

Sidawet C. Air 18-30-54 8-02-20 C

Afis N. Air 18-37-30 8-35-40 R

Agellal N. Air 18-43-02 8-07-17 C

18-43-00 8-10-02 F

18-43-00 8-07-14 Ch

Faodet N. Air 18-47-20 8-34-50 R

Iferuan[437] N. Air 19-04-10 8-22-45 R

19-04-28 8-22-22 C

19-04-18 8-24-32 F

19-04-12 8-21-20 Ch

19-04-03 8-24-24 J

Zurika N. Air 19-14-35 7-50-15 C

Uraren Western Desert 19-31-44 7-08-17 C

In Gezzam Western Desert 19-33-10 5-44-20 C

Heights above Sea Level.[438]

Iferuan 681 metres (F)

673 „ (C)

Uraren 485 „ (C)

Sidawet 554 „ (C)

Agellal 613 „ (C)

604 „ (F)

Auderas 798 „ (F)

Agades (T’in Shaman) 500 „ (F)

In Gezzam 374 „ (C)

Zilalet 557 „ (C)

Note.—The exact positions of the observations in the same localities are not identical in the case of all observers, which accounts for some of the apparent discrepancies.