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.     

HEIGHTS ON KILIMANJARO

Abstract

The Tanganyika Department of Lands and Surveys is to be congratulated on the successful Kilimanjaro Heighting Expedition recorded in the January 1954 issue of this Review (xii, 91, 194–210). In particular, K. T. Pugh is to be commended for his tenacity in makjng the summit observations under trying conditions.     

CONFORMAL REPRESENTATION

Abstract

On page 480 of the last number of this Review Capt. E. H. Thompson, R.E., in his paper on “The Condition for the Construction of a Conformal Projection”, deals with a subject which, in the opinion of the present writer, is rather insufficiently explained or dealt with in any text-book on Geodesy or on Map. Projections that he has seen. The explanations or proofs usually given are probably adequate if it can be assumed that the reader has a fairly good knowledge of the properties of functions of the complex variable.     

THE TRANSVERSE MERCATOR PROJECTION OF THE SPHEROID

Abstract

In January 1940, in a paper entitled “The Transverse Mercator Projection: A Critical Examination” (E.S.R., v, 35, 285), the late Captain G. T. McCaw obtained expressions for the co-ordinates of a point on the Transverse Mercator projection of the spheroid which appeared to cast suspicion on the results originally derived by Gauss. McCaw considered, in fact, that his expressions gave the true measures of the co-ordinates, and that the Gauss method contained some invalidity. He requested readers to report any flaw that might be discovered in his work, but apparently no such flaw had been detected at the time of his death. It can be shown, however, that the invalidities are in McCaw's methods, and there seems no reason for doubting the results derived by the Gauss method.     

FIGURES AND FANCIES

Abstract

I may say at once that this article has nothing to do with either the Gaiety chorus or the “Old Firm”: it is merely a statement of what seem to me the fancies in Dr. de Graaff Hunter's paper “Figures of Reference for the Earth”, E.S.R., No. 8,pp. 73–8. Many readers of the Review will share my gratitude to Dr. Hunter for his lucid presentation of the theory underlying the usual geodetic processes. I disagree with only one of his points, and its implications, but unfortunately that point is fundamental.     

THE MODIFIED MERIDIAN DISTANCE IN THE CONICAL ORTHOMORPHIC PROJECTION

Abstract

Recently the writer of this article became interested in the conical orthomorphic projection and wanted to see a simple proof of the formula for the modified meridian distance for the projection on the sphere. Owing to the exigencies of the war, however, he has been separated from the bulk of his books, and, consequently, has had to evolve a proof for himself. Later, this proof was shown to a friend who told him that he had some memory of a mistake in the sign of the spheroidal term in m⁴given in “Survey Computations”, perhaps the first edition. Curiosity therefore suggested an attempt to verify this sign, which meant extending his work to the spheroid. This has now been done, with the result that the formula given in “Survey Computations”, up to the terms of the fourth order at any rate, is found correct after all.     

THOUGHTS ON THE RUWANDIZ ROAD

Abstract

THE article on Road-Surveying in the East by Mr. J. N. List in the Empire Survey Review, No.6, 263–74, is well worthy of perusal. From the beginning, with his apt quotation from Kipling, to the end where he compares the text-book ideal of road location with the indifferent compromise amidst difficulties that the British engineer in the East is lucky to be able to achieve, I felt in accord with his observations. Having spent four years on a similar kind of work, I consider that this article well deserves the appreciation of its author's profession.     

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.     

Jacques Bertin,from classical training to systematic thinking of graphic signs

ABSTRACT

Nearly 50 years after the publication of the first French edition of Sémiologie Graphique, Jacques Bertin’s thought is more than ever alive, in cartography as well as in various other disciplines, such as graphic design or visual data analysis. This article recalls the main elements of Bertin’s career and puts forward the salient points of his reflection on graphics. Beyond many conceptual or technical innovations, Bertin’s essential originality appears to be his attempt to propose a general framework for graphical representations.     

THE TRAINING OF TECHNICAL ASSISTANTS IN MALAYA

Abstract

The subject of the training of European surveyors has received a great deal of attention in the course of the last two Empire Conferences, but little or no mention has been made of the native surveyor, his education, work, and prospects. The subject is very important, however, and the account of the training of Africans for the N. Rhodesia Survey, which appeared in vol. iii, no. 21 of the Empire Survey Review, was read with considerable interest. It may not be out of place, therefore, to introduce this paper on the means adopted in Malaya to recruit and train an efficient staff of subordinates or “Technical Assistants” as they are termed locally.     

AN OLD FILE AND A NEW ARC

Abstract

In his article “Standards of Length in Question” published in the last number of this Review (Vol. i, pp. 277–-84) Captain G. T. McCawgave us most interesting and valuable history concerning the questionable past of the international metre. He has, it may be assumed, exhausted published evidence; but he states that he can find no reference to invitations from this country to France and Holland to send their fundamental standards for comparison with others at the Ordnance Survey in the eighteen sixties.     

THE STEREOGRAPHIC SOLUTION OF THE SPHERICAL TRIANGLE

Abstract

In the course of his stimulating and suggestive paper in your recent issue, No. ro, pp. 226–38, Mr. A. J. Potter writes on p. 233 “but there is no simple construction by which X can then be found”, and again on p. 237 “a direct construction, if there be such”. This cheerful challenge invites the construction of a circle centred on a given line, passing through a given point thereon, and touching a given circle, and I have found the lure of Mr. Potter's gauntlet as irresistible as its recovery has proved delicate. In order to shoulder responsibility and by no means to claim highly improbable originality, let me confess that the problem is new to me and the two constructions I offer are my own; I venture to hope that Mr. Potter may consider one or other of them not unworthy of his epithet “simple”, though I freely admit the aptitude of his empiric procedure to its purpose. The proofs are not long, but for fear of overshooting my welcome I offer them to anyone for the asking; and for the same reason my diagrams are small and therefore mere.     

DISTORTING A NETWORK TO FIT CONTROL POINTS: AN ALTERNATIVE EXPRESSION FOR THE SCHOLS ADJUSTMENT

Abstract

Another form of Mr. Lauf's expression for a conformal adjustment of a system of coordinated points may be of interest. These are assumed to be already in harmony with i control points and are to be brought into agreement with j further points. (Mr. Lauf deals explicitly in his paper with the special case i = 2, j = 1, but he adumbrates a general solution.)     

APPROXIMATE METHODS OF SOLVING NORMAL EQUATIONS

Abstract

My attention has recently been drawn to an article by G. H. Menzies (E.5.R., vi, 46, 474) on this subject. The present note is intended to point out improvements in the Anér method, which he favours, and to refute some of his criticisms of the Relaxation method. References are to page and table numbers in Menzies's paper.     

FIGURES OF REFERENCE FOR THE EARTH

Abstract

1. The object of this note is to clear up what I believe to be some misconceptions regarding the use of a reference system by a surveyor of the earth's surface. In his article “An Aspect of Attraction”, E.S.R., No. 7, pp. 24–8, Major M. Hotine expressed doubts as to the validity of the process usually followed. I may say at once that I consider these doubts are unfounded.     

PERSONALIA

Abstract

The death occurred suddenly on 2nd February, 1935, of Mr. WILLIAM ERNEST BARRON,of Fort Jameson, Northern Rhodesia. Mr. Barron, who was 55 years of age, held the Certificate of Land and Mine Surveyor of the School of Mines, University of Otago, New Zealand, and the Mine Surveyor's certificate of competency, Transvaal, and in 1913 was licensed as a surveyor in Northern Nigeria. In 1921 he was licensed as a surveyor for private practice in Northern Rhodesia. He was for over four years Chief Surveyor to the Van Ryn Gold Mines Estate, Ltd., and for two years to the Bantjes Consolidated Mines, Ltd., and for some time to Modderfontein East, Ltd. He was first employed in Northern Rhodesia as Mine Captain in charge of survey work at Broken Hill Mine, and from 1923 to 1928 was engaged by the Rhodesia Broken Hill Development Co., Ltd., in the survey and setting out of all work in connexion with that Company's Hydro-Electric Power Scheme at Mulungushi. Upon the completion of this work, in which Mr. Barron showed the greatest skill and accuracy under difficult conditions, he was engaged by the North Charterland Exploration Company as surveyor, and at the time of his death he was carrying out the survey of that Company's Land Concession, an area of 10,000 square miles on the south-eastern border of Northern Rhodesia. By his death the survey profession has lost an able and keen personality, and he will be greatly missed by the many friends he made in this country. He leaves a widow and son to mourn his loss.     

THE EARLIEST GEODETIC TRIANGULATION

Abstract

WILLEBRORD SNEL VAN ROIEN, the “learned Snellius,” was born in 1580 at Leyden, where his father Rudolf was Professor of Science. He naturally proceeded to the university, and made such rapid progress under his tutor, L. van Ceulen, that he was already in 1600 delivering lectures on Ptolemy's “Almagest.” With his mind developed by travel in Europe, including a residence of some duration at Prague, where he was associated with Tycho Brahe before that great observer's death in 1601 and with the still more eminent Kepler as another of Brahe's pupils, he had acquired such scholarship as to publish in 1608 a daring reconstruction of the defective work, “De sectione determinata,” by Apollonius of Tyana. This was the year of his marriage to Maria de Lange, daughter of the Burgomaster of Schoon.     

Jacques Bertin’s legacy in information visualization and the reorderable matrix

ABSTRACT

Jacques Bertin’s legacy extends beyond the domain of cartography, and in particular to the field of information visualization where he continues to inspire researchers and practitioners. Although in the late twentieth century his books were out of print, their reedition around 2010 has steered a renewed interest and inspired new generations of researchers to reinterpret the principles of Semiology of Graphics and La Graphique in a time of interactive computers. In particular, the work of Jacques Bertin on the reorderable matrix has been very challenging in his time, and the quest to its automation has not been satisfactory to him. This article summarizes Bertin’s approach to the reorderable matrix, underlines the limitations of fully automated reordering methods, and introduces Bertifier, a hybrid system to reorder matrices using a combination of machine assistance and human control.     

THE TRANSVERSE MERCATOR PROJECTION

Abstract

I. Introduction.—Map projection is a branch of applied mathematics which owes much to J. H. Lambert (v. this Review, i, 2, 91). In his “Beyträge zum Gebrauche der Mathematik und deren Anwendung” (Berlin, 1772) he arrived at a form of projection whereof the Transverse Mercator is a special case, and pointed out that this special case is adapted to a country of great extent in latitude but of small longitudinal width. Germain (“Traité des Projections”, Paris, 1865) described it as the Projection cylindrique orthomorphe de Lambert, but he also introduced the name Projection de Mercator transverse or renversée; he shows that Lambert's treatment of the projection was remarkably simple.