TRIGONOMETRIC HEIGHTS AND REFRACTION

Abstract

In the past there has been considerable discussion on the above subject in this Review. There is a bibliography at the end of this article in which the full titles of previous articles are given. For brevity, reference to them in the following text is made by number only. Recently, Gulatee summarized present knowledge and asked how other Survey Departments dealt with this matter. Consequently, it was considered that it would be helpful to set out in detail the procedure adopted by the Directorate of Colonial Surveys for obtaining trigonometric heights, with particular reference to primary and seoondary chains and nets.     

THREE YEARS AND MORE OF THE RISING SUN or A COLONIAL SURVEY DEPARTMENT UNDER A NEW MASTER

Abstract

The late war has been responsible for many unusual situations—not the least of which was that of certain British Colonial Surv1ey Offices passing under the control of an Asiatic Invader, and it is thought that the story of one of them—the Survey Department of Malaya—will not be without interest to readers of this Review.     

REPRODUCTION OF THE 1/1,250 AND 1/2,500 SCALE NATIONAL PLANS,OF GREAT BRITAIN

Abstract

Field work for the 1/1,250 scale re-survey of Great Britain was fully described in an article by Brigadier R. P.Wheeler in the April, 1948, issue of this Review (ix, 68, 234–247). The object of this article is to outline the method’ of reproduction of these plans and of the resultant 1/2,500 scale plans of urban areas. The 1/2,500 series covering rural areas is a separate problem, one of revision rather than re-survey. Experiments are in hand now to find out the best ways to provide field material and produce the final plans on National Grid sheet lines. The 1/1,250 scale series will contain about forty thousand plans and the 1/2,500 series of the same areas about nine thousand. It is therefore important that production methods should be straightforward and maintain an economical balance between the use of men and machines.     

NUMBER ONE HUNDRED

Abstract

Readers will notice that this issue of the Review is numbered 100 and, as it has always been published quarterly, this means that it has now been in existence for 25 years and so celebrates its silver jubilee.     

RADAR CONTROLLED AIR SURVEY PHOTOGRAPHIC OPERATIONS IN AFRICA 1946–1952

Abstract

(a) Deployment of personnel and equipment. The areas to be photographed and the specifications of photography are laid down by the Direotorate of Colonial Surveys.     

THE SCHOOL OF MILITARY SURVEY AND ITS COURSES FOR COMMONWEALTH SURVEYORS

Abstract

On the first of January 1949 the Survey Training Centre of the Royal Engineers became the School of Military Survey. In the previous two years over fifty Colonial Survey Officers or Probationers came to the Training Centre as students on various courses. Many of these have now taken their places in the Colonial Survey Service. More students may come in the future not only from the Colonies but also from the Dominions, for just as the Military Survey courses are open to the military officers of the Dominions so are the Colonial Survey courses open to the survey students from the Dominion Governments. Some information about the School and courses may be of interest to these potential students and to many readers of this Review, and these notes have been written with the intention of providing this information     

DIRECT USE OF AIR PHOTOS FOR CADASTRAL PURPOSES IN ZANZIBAR

Abstract

Since a number of factors have combined to separate the second part of this paper from the first appearing in the E.S.R., issue No. 63, Volume IX, pp. 1–14, and written by Sir Ernest Dawson, I feel that some emphasis, already given, may reasonably be reproduced. To quote from Sir Ernest's paragraph on the Main Problem :—“The crux of the matter which I had been invited to solve, was the definition and record in a simple, sure and economical way, of the increasing number of unstable small holdings in their tangled setting throughout the Protectorate.”     

TRIANGULATION IN TANGANYIKA TERRITORY

Abstract

This is a résumé of the triangulation work completed within the Mandated Territory of Tanganyika, formerly German East Africa. The period covered includes the German Occupation down to 1915 and also the Colonial Office Administration from 1919 to the present day.     

DETERMINATION OF TAPE TEMPERATURES ON THE MEASUREMENT OF THE WANKIE AND SABI GEODETIC BASES,SOUTHERN RHODESIA (1953)

Abstract

The Wankie Geodetic Base was measured in May 1953 and the re-measurement of the Sabi Geodetic Base was also completed during the month following. For these measurements the standard “Macca” equipment was used, the gear being lent to the Southern Rhodesia Government by the Directorate of Colonial Surveys. As it was anticipated that both measurements would be made under hotter and more sunny conditions than normally prevail in England, the Directorate of Colonial Surveys suggested that the opportunity be taken of carrying out further tests in the determination of temperatures by the “resistance thermometer” as described by Messrs. Clark and Johnson of the National Physical Laboratory in their paper on the “Measurement of Temperature of Geodetic Surveying Tapes. Accordingly, through the good officesof the Director of the National Physical Laboratory, the apparatus comprising the resistance theremometer was made available for use on these two base measurements.     

RADAR CONTROLLED AIR SURVEY PHOTOGRAPHIC OPERATIONS IN AFRICA 1946–1952

Abstract

In 1943, the Colonial Research Committee accepted a proposal submitted by the Colonial Survey and Geophysical Committee to the effect that a Central Colonial Survey Organization should be established to undertake geodetic surveys and topographical mapping, publish the work completed, hold the required equipment and maintain the necessary records. In order that such an organization, if approved, could commence to operate as soon as possible after the end of war, a detailed scheme for same was called for by the Colonial Research Committee.     

AIR SURVEY IN NIGERIA

Abstract

Early in 1946 a Central Survey organisation was set up with headquarters in London to undertake, in conjunction with the R.A:F., the air survey mapping of large areas of the Colonial Empire, in connection with Colonial Development programmes.     

THE YEAR 1933 IN CEYLON

Abstract

IN the absence on leave of the Surveyor General, a full Report for the Colonial Survey Committee was prepared by Mr. R. W. E. Ruddock, the Deputy Surveyor General. The Department in Ceylon covers so many activities that it would be impossible to mention here more than a few.     

TRAVERSE ADJUSTMENT: WHY NOT LEAST SQUARES?

Abstract

In the above article by Mr H. L. P. Jolly published in a previous issue (E.S.R., vol. iv, no. 28) the author, after referring to the precision of the Nigerian traverses, makes the statement that measurements of the highest accuracy are worthy of the best possible methods of adjustment. But this argument cuts both ways. For in general the greater the accuracy of measurement the smaller will be the ultimate misclosure to be eliminated; so that different methods of adjustment will produce smaller and smaller variations in the corrections, until in the limit when there is no error we should obtain the same result however much latitude we permitted in the adjustment.     

SURVEY FOR COLONIAL DEVELOPMENT

Abstract

The Inaugural General Meeting of the newly-formed Land Surveying Division of the Royal Institution of Chartered Surveyors was held at the Headquarters of the Institution in London on Wednesday, 14th December, 1949, when the following paper was read by Brigadier M. Hotine, C.M.G., C.B.E., F.R.I.C.S., Director of Colonial Surveys. This meeting, which is the precursor of others that are to be held in future at regular intervals, is of particular importance to surveyors since it was the first occasion on which those of them who had joined the Institution recently, but. werenot members oj any of the Committees appointed in connection with theformation of the Land Surveying Division, had been able to meet together as a separate Division of the I nstitu.tion, and thus to take their part in one of the Institution's normal activities. Brigadier Hotine's paper, together with an account of the Proceedings of the meeting, was published in the January issue of the Journal of the Institution and readers who belong to the Institution will thus already have had an opportunity of reading it. A large number of our readers, however, do not belong to the Institution, and do not see the Journal, and hence, and especially considering the special importance of the occasion and the intrinsic interest to all land surveyors of the subject with which the paper dealt, we have obtained the kind permission of the Editor to reproduce from the Journal the text of the paper and of the discussion which preceded and followed it.     

SOME EFFECTS OF PULLEY ECCENTRICITY IN BASE MEASURING APPARATUS

Abstract

The comprehensive paper on the suspension of tapes by M. Hotine in the January, 1939, issue of the Empire Survey Review (v, 31, 2) did not contain any reference to this question, as was pointed out by A. J. Morley in a letter published on page 261 in the same volume (v, 34, 261). A brief analysis has been made by F. Yates of the theoretical effects of pulley eccentricity and misalignment (“Gold Coast Survey Department Records” VoL III, 1931, page 43) but I have not seen any further reference to the subject and have recently experienced the effects of such a defect in our own apparatus, so the followingnotes nlay be of interest. Before proceeding to details I will describe briefly those parts of the apparatus which are considered here and give a short summary of the whole paper.     

THE LATE CAPTAIN McCAW'S CONTRIBUTIONS TO THE E.S.R.

Abstract

The volume of this Review which has just been completed commenced with a memoir of the first Editor, the late Captain G. T. McCaw, C.M.G., O.B.E., M.A., who died in October 1942, and, in view of his great services to the Review and to the survey world in general, it is thought to be not in-appropriate that this, the first number of a new volume, should contain a list of his contributions to the Review. The power and versatility that they display are remarkable.     

THE COLOURS QUESTION

Abstract

The foundation of my former paper was nothing more substantial than a recollection of reading or hearing long ago that the property of the four colours existed in practice but had never yielded to strict theoretical analysis. I am therefore most grateful to Col. G. S. C. Cooke and Mr. G. W. Ross Jackson for their letters to the Editor (vol. iii, no. 15, pp. 52–5) citing the relative authorities, as they enable me to locate and acknowledge my debt to Mr. W. W. Rouse Ball, whose book was certainly in my hands in the Oxford Union Library some forty years ago. I wish I could remember his demonstration of the problem, but my subconscious faculties seem, from what Col. Cooke says, to have evolved a tolerable imitation of it, and until I have an opportunity of seeing the book again or of consulting any of the other authorities, I shall rest content in the assurance that, wherever my arguments may differ in substance from those of Mr. Rouse Ball, my errors will be so flagrant as to deceive none but myself, though my serenity in this connexion is somewhat shaken by the fate that seems to have attended the first welcome efforts to unmask a few of them.