PUBLIC RECORD OFFICE
Reference :-
། ༴། ། ། ། །།
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C.O.8
885
18 PUBLIC RECORD OFFICE, LONDON
ALLY WITHOUT PERMISSION OF THE BE REPRODUCED PHOTOGRAPHIC- COPYRIGHT PHOTOGRAPH-NOT TO
SIR,
(No. 85/110/1907.)
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Enclosure in No. 46.
Survey Department, Lagos, West Africa, April 29, 1907.
In compliance with your request of the 25th instant, I beg to forward a progress report on the present state of the survey operations which are being conducted for the projection of a new map of that portion of the Western Province set forth in the report of the Colonial Survey Committee for 1906.
2. The area to be completed by the end of this month is hatched in neutral tint on accompanying plan, and will be seen to embrace an area somewhat larger than that already mentioned.
3. The actual mileage completed during my present tour totals as follows:-
1.
Theodolite work, 200 miles.
Prismatic compass surveys, 3,000 miles.
Permanent marks for future reference, 200. Observations for latitude, 100.
Observations for azimuth, 100.
Observations for longitude, 20.
The theodolite work was chiefly for the "closing" of "surrounds" which have been filled in " by prismatic compass surveys.
5. Every line in the whole of this work (however short) has been fixed by actual bearing and distance; this may appear an unnecessary refinement, but the experi- enced surveyor will recognise that slovenliness in these small matters always leads to considerable errors in long surveys; he will also know that complete field-notes cannot be kept if the bearing and distance of each line be not recorded.
It should also appear, from the amount of work already completed, that my insistence on accurate surveys has not prevented an extremely satisfactory output.
6. The plotting of the surveys (so far as is at present completed) shows that the surveys have been carried out in an extremely satisfactory manner.
7. The terminals of each traverse have been connected to permanent marks on the "theodolite surround" and the "closes" require (so far as plotting has been completed) little or no adjustment.
8. I have just returned from a two months' trip, during which period I travelled about 700 miles. The tour was chiefly directed to the checking of some 200 important stations.
These positions were fixed when possible by direct triangulation from hill-tops; in cases where triangulation could not be conducted, the method of latitude and azimuth was resorted to; and in cases where neither of these methods were possible (indeed, where they were) the points were located by refined latitude. and time obtained from six watches, whose resting and travelling rates had previously been determined with great care.
9. I have no hesitation in stating that the plan projected from this work will be of a high order of accuracy.
10. All towns, villages, rivers, roads, and tracks have been defined; a rough census of the population has been taken, and the economic and geologic condition of the country has been carefully studied.
11. As the wet season will shortly set in, little more survey work can be expected till the end of September next, and, as our drafting staff is altogether inadequate to cope with the plotting, the surveyors will shortly be called into complete the plotting up of their respective field-notes.
12. A finished plan of the area already referred to should be completed by the end of this year, and a very comprehensive report will accompany it.
13. There are several sources of information upon which I desire to draw, the chief of which is a series of questions compiled by Mr. Birtwistle, Commercial Intelligence Officer, and forwarded to the Secretariat some five months ago. I shall be much obliged if these could be supplied me at an early date.
14. With the exception of the work done by Captain Ambrose (whose surveys are always excellent, but which really do not come into this year's work), little or no use could be made of the work forwarded by the various District Commissioners, and it was found necessary to re-survey all their work. Still, such plans as those furnished by the late Major Reeve-Tucker would be of value, as it is quite often necessary to have corroborative evidence in the case of towns, rivers, &c. For this
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and other satisfactory reasons, I trust that the War Office may be able to supply me with all the maps, &c., of the Western Province which they can conveniently spare.
15. Unfortunately, there will be, at any rate for the present, one serious omis- sion on this map, i.e., bench-marks determined by barometric levelling. I had hoped that it would have been possible to carry out a comprehensive scheme of baro- metric levels, covering the entire area to be surveyed during this year, but the estimates submitted by this Department were cut down to such an extent as to render this most important operation quite impossible.
16. I have found from long experience in localities such as this, where the baro- meter is generally remarkably steady, that two barometers accurately compared and intelligently used, following each other at intervals of, say, 20 miles, can be depended upon to establish bench-marks (if a fairly large number of readings be. taken) to an accuracy of less than 10 feet. Thus, for a distance of 200 miles, the error between terminals should not exceed 30 feet.
17. In view of the fact that very large sums of money are being expended on road construction, it is imperative, from a sound commercial standpoint, that these bench-marks should be established at suitable intervals, and it is hoped that in future. estimates the provisions which are made for this most important work may meet with approval.
18. I may mention that His Excellency's approval of the survey of Egba territory has not, as yet, been received. It is hoped that it may be possible to carry out this survey during the present year.
19. In conclusion, I have much pleasure in stating that the chief factor in the very satisfactory progress which has been made in both surveys and compilation work is the highly creditable manner in which the whole of the staff, both European and native, have carried out their respective duties.
I have, &c.,
The Honourable
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The Colonial Secretary,
Lagos.
No. 47.
E. P. COTTON,
Director of Surveys.
COLONIAL SURVEY COMMITTEE. MINUTES OF MEETING OF MAY 27, 1907.
PRESENT:
Colonel R. C. Hellard, R.E., Director-General, Ordnance Survey;
Major C. F. Close, C.M.G., R.E., Topographical Section, General Staff, War Office;
and Mr. H. J. Read, Colonial Office; Mr. W. C. Bottomley, Colonial Office, Secretary,
and
1. Uganda Surveys.
Major Hills's report of the 9th of April, 1907, was read and considered. The Committee generally concurred in the views expressed by Major Hills, and, in par- ticular, emphasized the necessity for relieving the Survey Department of engineering services and the desirability of arranging for a recess season. They noted his remarks as to the doubtful utility of the platforms recently introduced for the pur- pose of expediting the cadastral work by avoiding the necessity for cutting the clephant grass. It was recommended that the Commissioner's attention should be drawn to the importance of marking the boundaries of estates in a permanent manner and that he should be asked to consider how permanence might best be secured.
Major Hills's reference to the necessity for a larger angle-book was noted, and Major Close agreed to arrange for the preparation of a book of foolscap size, copies of which could be sent out to the Colonies and Protectorates concerned, with a view to their obtaining the necessary supply through the Crown Agents for the Colonies in the usual way.
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