THE CONFORMAL TRANSFORMATION OF A NETWORK OF TRIANGULATION

Abstract

In a recent issue of this Review, an example is given of the conformal transformation of a network of triangulation using Newton's interpolation formula with divided differences. While the application of the method appears to be new, attention should be drawn to the fact that Kruger employed Lagrange's interpolation formula in a discussion and extension of the Schols method in a paper which was published in the Zeitschrift für Vermessungswesen in 1896. A reference to this paper was given at the end of the paper, “Adjustment of the Secondary Triangulation of South Africa”, published in a previous issue of the E.S.R. (iv, 30, 480).     

British military education,mapmaking, and military 'map-mindedness' in the later Enlightenment

Abstract

The Military Institution at Madras (1804–16) illustrates the centrality of surveying and mapping to late Enlightenment concepts of 'military science' and thus their centrality to the education of junior officers beyond the rudiments of military lore and drill. Pragmatically, the institution's field mapping exercises were used to provide basic topographic maps for south-east India (the Carnatic); the institution's students were also intended to serve after graduation on survey duty elsewhere in southern India. Intellectually, mapmaking was held to epitomise the 'scientific spirit' which military reformers desired to inculcate in the young ensigns: it combined mathematical and logical thought (theory) with concrete military results (practice). These last points underlie the conceptual issues of the early nineteenth-century militarisation of government cartography in Europe and the increasing 'map-mindedness' of military thinkers.     

Arno Peters changed the World! Development Education and the Peters' Projection

Abstract

This paper describes, from a map librarian's perspective, an investigation into the feasibility of the provision of digital mapping for use by students in a British academic library. Establishing the funding has been a significant part of the project. This has included consideration of hardware as well as the pricing structures for the supply of digital cartographic data.     

Relief and Colour

Abstract

Most maps which depict the earth's relief do not convey information about the colour or texture of the earth's surface. Ways of embodying these additional elements into hill-shaded maps are proposed by the Senior Lecturer in Geodesy, Israel Institute of Technology (Technion).     

A NOTE ON CLARKE'S FORMULAE

Abstract

An elegant proof of Clarke's Formulae for lines of medium length has been given by G. T. McCaw. It is based on the properties of polar triangles in spherical trigonometry, and on the application of Legendre's Theorem.     

ICA Research Agenda on Cartography and GI Science

Abstract

The paper presents the ICA research agenda on Cartography and GIScience. The first part discuses the research topics and the second part deals with the 'implementation' of the agenda by the ICA Commissions and Working Groups.     

LEAST SQUARES ADJUSTMENTS OF TRIANGULATION

Abstract

Mr. Rainsford's paper in E.S.R. No. 78 establishes as thoroughly as one can wish by computational example that there is little to choose in relative accuracy between direction adjustment and angle adjustment, and that the deciding factor is really ease and speed of computation.     

Influencing the Perception of Contour Lines

Abstract

Two possible causes of the failure of map users to successfully interpret relief forms from contour maps are Gibson's texture gradient effect which may give false depth cues; and, the expectancy or prior set developed from previous experience by the map reader. In the two experiments reported attempts were made to alter subjects' expectancy by providing cues or contextural information related to the task of interpreting a number of unquantified contour patterns. Although expectancy has proved to be a dominant influence on contour interpretation, successful priming in the experiments provided subjects with a number of conflicting but valid hypotheses which were often resolved in the direction of the texture gradient.     

Measuring the Coastline from Maps: A Study of the Scottish Mainland

Abstract

While attempting to devise a methodology for the assessment of the impact of planning decisions on the coastline of Scotland, it became apparent that a means of mapping information concerning the coastline and coastal zone was necessary. This meant that the maps had to be capable of being produced in bulk, they should be easy to alter and produce at different scales and with different information. It was therefore decided to investigate the potential of computational techniques to produce the required maps. This was performed by employing a d-Mac digitising table to generate the required coordinates and by processing the information on the University of Aberdeen's ICL system 4/70 computer, the output being on drum plotter.     

THE ADJUSTMENT OF A FIRST-ORDER LEVELLING NETWORK

Abstract

In the E.S.R. January and April numbers of 1955, Vol. xiii, Nos. 95 and 96, Mr. Hsuan-Loh Su described the “Adjustment of a Level Net by Successive Approximations and by Electrical Analogy”. It does not seem to be as generally known as it should be that the rigid least square solution can be greatly simplified by utilizing the electrical analogy and solving by Kirchhoff's method. The method as detailed below has been in use for over 40 years.     

'Drawing the Coral Heads': Mental Mapping and its Physical Representation in a Polynesian Community

Abstract

Indigenous people throughout the world developed their own mapping skills and systems of knowledge. While Westerners are prone to overlook these communities' geographical knowledge and imagine their mapping activities to be primitive or non-existent, their mental maps are often impressive in sophistication and detailed even if based on cosmologies that are quite foreign to Western thinking. This article depicts a mental map of the ocean floor shared by Polynesians of Anuta, a remote community in the Solomon Islands. It situates Anuta's reef map in relation to academic discussions of indigenous cartography and describes the process that resulted in the map's physical representation.     

SIR DAVID GILL AND THE GEODETIC SURVEY OF SOUTH AFRICA AND THE ARC OF THE 30TH MERIDIAN

Abstract

In the memoir of the late Capt. G. T. McCaw which appeared in the January number of this Review (vii, 47,2), reference was made to the part which the late Sir David Gill played in the origin of the work on the survey of the Arc of the 30th Meridian in Africa. This year is the centenary of Gill's birth, as he was born in June 1843, and it is therefore timely to give some account of his work during his long term of office as Her Majesty's Astronomer at the Cape which resulted inthe inception and completion of the Geodetic Survey of South Africa and the survey of the Arc to the southern shores of Lake Tanganyika. He died on 24th January 1914.     

THE YEAR 1933 IN NIGERIA

Abstract

The continued fall during the year of the price of local raw products on the world's markets led to a deficit in the estimated revenue, necessitating further retrenchments throughout the Nigerian Civil Service. The Survey Department's personnel was reduced by 8 Europeans and 24 Africans, thus decreasing since 1930, the first year of retrenchments, the Department's permanent staff by 46 per cent. of its European and 17 per cent. of its African Officers. The establishment at the end of the year comprised 31 European Officers, 49 African Surveyors, 5 African Computers, 35 African Draughtsmen, and 8 Lithographers and Sunprinters.     

THE YEAR 1933 IN THE FEDERATED MALAY STATES AND STRAITS SETTLEMENTS

Abstract

THE programme of retrenchment referred to in last year's report was practically completed, with the result that the gross expenditure has been reduced to a figure well within the limit set by the Retrenchment Committee. Actually, gross expenditure was £128,121 (over 45 per cent.) less than in 1930, the peak year in expenditure.     

A NOTE ON THE TRIGONOMETRICAL SURVEY OF SOUTHERN RHODESIA

Abstract

After the completion of Simms's Geodetic Chain in 1901 and the publication of the results in 1905—Volume iii of the Geodetic Survey of South Africa—nothing further of a geodetic nature was done until 1928 when a short chain was run westwards from Simms's chain, at about latitude 17° 10′, to fix the Copper Queen mining area. The Eastern Circuit was commenced shortly after this; it runs from Salisbury eastwards to the Portuguese Boundary, southwards through Umtali to about latitude 20° and then westwards, joining Simms's chain again to the east of Bulawayo. Another chain running north from Simms's work has been commenced near Bulawayo. The several series are exhibited on the outline map attached.     

Code as Cartography

Abstract

Provincial Atlas of People's Republic of China (Chung hua ien min kung wo kuo fên shêng di t'u chi). 190 x 265 mm. pp. 251 (84 pages of maps). Peking: Map Publishing Society (di t'u ch'u p'an shê), China, Oct., 1974. 6.30 Yuan     

TACHEOMETRIC SURVEYING AND THE USE OF THE DIFFERENTIAL SLIDE RULE

Abstract

In the E.S.R. No. 17 of July 1935, page 138, there appeared an article by Prof. F. A. Redmond on “The use of Even Angles in Stadia Surveying”. Since I have given this method a six-months' test in the field, using Prof. Redmond's “Tacheometric Tables” for the reduction of the measurements, the conclusions reached may be of some interest.