CO885-(21-23) — Page 445

PUBLIC

RECORD OFFICE

Reference :-

4117 CO. 885

יוןוּךָ

22 PUBLIC RECORD OFFICE, LONDON

ALLY WITHOUT PERMISSION OF THE BE REPRODUCED PHOTOGRAPHIC- COPYRIGHT PHOTOGRAPH-NOT TO

Present work of

mines

section.

Future

work of

mines section.

Object of topo- graphical surveys.

Topo- graphical anrvey of Nigeria.

Time to complete map of Nigeria.

Value of

topo- graphical survey to railway location.

Object of instine- tion.

42

The majority of these lands lie in the Central, Zaria, and Nassarawa Provinces, both in and outside the Closed Minefield " shown on the attached map (Appendix I.).

The present situation in the minefield is given in paragraph 31, the work of the In paragraph mines section being confined to the Central Province portion alone. 32 it will be noticed that I advocate the mines section taking over all the Central, Nassarawa, and Muri Provinces at an early date.

Eventually, the work of the mines section should cover all those provinces in Nigeria which have no revenue section. In provinces where revenue sections exist mines surveys should be conducted by them.

10. The objects of the topographical survey are:-

(i.) To provide a main framework for all surveys in Nigeria.

(ii) To produce a contoured map of Nigeria.

(iii.) To produce special maps to assist railway and motor road location. (iv.) To produce special topographical plans of stations, lands held under mining licences, political boundaries, and other special surveys in the area of the season's work.

(v.) To collect the material for a full and detailed gazetteer of Nigeria. 11. The topographical branch is now completing its fourth field season, and by that time will have completed 25,000 square miles in the Southern Provinces. In the second and third seasons, the annual output of the previous season was doubled. A set-back was experienced during the present season, owing to unusual local As the native staff gradually difficulties, and to a strike of part of the native staff. attains to its full strength and experience, a gradually increasing annual output will result until from 15,000 to 20,000 square miles a season may be expected. At this rate it should complete the topographical survey of Nigeria in from 10 to 12 years, allowing for the fact that the detailed survey of provinces possessing revenue sections, themselves map producing, will not be necessary.

12. The value of a contoured map to railway location may be estimated when it is considered that about 70 miles of deviation on the old Lagos Railway have been found necessary. It is highly probable that, had the present sheets of the contoured map existed when the railway was located, about 60 miles of these devia- tions at £4,000 to £5,000 a mile could have been saved; the sheets concerned cost about £8,000 to survey and publish.

As will be seen on reference to this year's report of the Colonial Survey Com- mittee the special map made by the topographical branch working ahead of the railway location from Port Harcourt has proved of such value that the area of next

• season's work has been extended to the Northern Provinces along the proposed route of the new railway.

The proposed change of scene has the advantage that it will not interfere with the methodical survey of the country, but has the technical disadvantage, so long as the Northern and Southern Provinces surveys exist as separate units, that both are working independently in the same area.

13. In a tropical country the chief duty of the European surveyor is super vision (besides the execution of the more scientific branches of survey work); that of the native surveyor, the execution of 90 per cent. of the fieldwork and all the drawing,

The European is expensive, owing to salary, passages, long leave, and transport. It therefore follows that the greater the proportion the native staff bears to the European staff the greater the economical working of the department, always provided that organisation is good, that the right class of European is employed. and that the number of natives per European permits of efficient supervision.

The object of the instruction carried out in the survey schools and of the field training and drafting work in the various branches is to provide a sufficient native staff for the above object.

The question of the proportion of natives to Europeans depends on the nature of the work and on the fact whether the native is working in his own country. In the topographical branch in Yoruba land it was found that one European could supervise eight Yoruba surveyors; in Ibo land not more than about four Yorubas.

In ordinary cadastral work the proportion is about three or four to one. In the revenue surveys the proportion has yet to be accurately ascertained, but will probably be found to be between 10 and 20.

• Colonial Reports (Auunal) No. 775.

14.

43

The necessity for the revision of the 1:250,000 and 1:2,000,000 maps of Compl-

lation of Nigeria has been remarked by the Governor-General. A very large amount of

provisional material exists in the sketches done by soldiers and political officers. An experi- map. enced officer to adjust these sketches both in the field and in the office is urgently required and is not available.

In view of the pressure of work at present existing in the Survey Depart- ments of Nigeria, and which is not likely to be lessened by the large amount of instruction that will be required by the new European staff in the Northern Pro- vinces, I am suggesting later in this report the temporary employment of an Assist- ant Surveyor-General for three tours. One of his chief duties would be the compi- lation of these maps.

II. Areas to be dealt with and the Scales of the Surveys. 15. The areas to be dealt with are shown on the map in Appendix I. It will be noticed that a careful division of responsibility will be required in 1914-15 between the Mines Section and the topographical branch to prevent dupli- cation of work. As both are working under the Surveyor-General's orders, this can be arranged. The same object will be difficult to attain in co-ordinating the work of the topographical branch and the Northern Provinces survey, as they belong to different Survey Departments.

Publication

Publication

16. The scales used should be as follows :—

Scales.

Scales.

(1.) Standard map of Nigeria, 50-ft. contours... (ii) Standard map Special Sheets of congested

districts, 25-ft. contours

(iii) General map of Nigeria, 200-ft. contours... (iv) General map of Nigeria, 500-ft. contours... (v.) Topographical surveys, according to nature

of country

(vi.) Cadastral and revenue surveys

(vii) Town plans

(viii.) Government stations

(ix.) Revenue map sheets

(x.) District revenue maps

(xi.) Mining leases

(xii) Exclusive licences to prospect (xiii.) Minefield map

1:125,000

1:62,500 1:250,000 1:2,000,000

1:12,500 to 1:62,500 1:100 to 1:10,000 1:1,000

1:1,000 to 1:5,000

1:2,500

1:25,000

1:1,000, 1:2,500, or 1:5,000

1:25,000

1:62,500

III. Junction of the Surreys with those of the Southern Provinces of Nigeria, and the continuity of the Main Framework.

Areas.

Scales.

17. Reference to the map (Appendix I.) shows that the surveys of the Northern Junction of and Southern Provinces will join automatically, owing to the programmes laid down for the topographical branch for the next three seasons (1914-1917).

18. The remarks in the preceding paragraphs also apply to the junction of the framework.

surveys of

N. P. and S. P. Continuity of main

work.

At the present moment, owing to the demand for detail surveys in widely- frame separated areas, the main framework of the Protectorate is regrettably but unavoid- ably patchy, and consists of :-

33547

+4

(i.) The Western_Triangulation (invar-base) covering the area marked 1910-1913," and to Jebba, Öndo, and Akure. This is joined to the Lagos datum by several traverses. Lagos datum is fixed telegraphically from Cape Town, and agrees to within one second of arc with the telegraphic longitude of Cotonou fixed from Brest. The latitude of Lagos is the result of very accurate astronomical observations, and has been accepted as correct, although it possesses the unknown error due to attraction.

(ii) The Udi Triangulation (invar-base).-Assumed latitude and longi- tude on astronomical and telegraphic data. Connected to Calabar and Port Harcourt by traverses.

(iii) The Naraguta Triangulation (invar-base).—Assumed data as in case of Udi. I'sed for minefield survey.

(iv.) The Kano Base (invar), with a small amount of triangulation, laid down for the revenue section.

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