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《测量评论》2013,45(5):207-214
Abstract Artillery Survey.—Included in the term “Artillery Survey are two distinct problems, the first that of determining the “line” and “range” at which fire should be opened, and the second that of laying the gun in the required line. To appreciate these problems it. is necessary to know a little about the technique of gunnery, and for the benefit of those who have no acquaintance with the subject the following brief résumé may be given. 相似文献
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《测量评论》2013,45(60):217-219
AbstractMap Projections.—A matter that should have been mentioned in the original article under this title (E.S.R., vii, 51, 190) is the definition of a map projection. In the list of carefully worded “Definitions of Terms used in Surveying and Mapping” prepared by the American Society of Photogrammetry (Photogrammetrie Engineering, vol. 8,1942, pp. 247–283), a map projection is defined as “a systematic drawing of lines on a plane surface to represent the parallels of latitude and the meridians of longitude of the earth or a section of the earth”, and most other published works in which a definition appears employ a somewhat similar wording. This, however, is an unnecessary limitation of the term. Many projections are (and all projections can be) plotted from rectangular grid co-ordinates, and meridians and parallels need not be drawn at all; but a map is still on a projection even when a graticule is not shown. Objection could be raised also to the limitation to “plane surface”, since we may speak of the projection of the spheroid upon a sphere, or of the sphere upon a hemisphere. Hence, it is suggested that “any systematic method of representing the whole or a part of the curved surface of the Earth upon another (usually plane) surface” is an adequate definition of a map projection. 相似文献
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AbstractOld text-books in English frequently referred in very loose terms to the “run of the bubble”. The meaning of the term was often so doubtful as to leave the impression that the writers themselves had vague notions on the theory of the level; certainly they must have left the student often in a state of bewilderment. In the sense in which it was used the phrase “run of the bubble” appears to have been intended to suggest a line parallel to the directrix. 相似文献
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AbstractCadastral Traversing.—For cadastral purposes traverses are now being executed with an accuracy wholly unnecessary for even large topographical scales. But since “accuracy” varies from a mile to a micron, according to the viewpoint of the observer, it is advisable to exhibit a cadastral traverse, care being taken that it is not an example of that not very uncommon occurrence in which fortuity apes precIsIon. If the accuracy of the example is somewhat unusual, it can be said with assurance that it is not very unusual. 相似文献
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《测量评论》2013,45(48):59-68
Abstract“RECTIFICATION” is the term used to describe the production from a tilted air photograph of a print or image from which the effects of tilt have been eliminated. It consists, essentially, in the projection of the original photograph on to another selected planenormally, but not necessarily, representing the horizontal. 相似文献
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《测量评论》2013,45(11):264-268
AbstractI 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. 相似文献
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AbstractAn additional note on these problems, which were considered in No. 23, pp. 49-53, appears desirable. The “alternative form” on p. 51 was presented in a manner calculated to demand an explanation; since none has been forthcoming no apology is necessary for a further reference. 相似文献
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《测量评论》2013,45(21):422-427
AbstractThe survey of “mailos” or native estates in the Kingdom of Buganda has taken a prominent place in the annual programme of the Survey Department of Uganda for over 30 years past. The survey, which has covered some 17,000 square miles and is now practically complete, has some unusual features, and although it has no claims to refinement or to great precision, a short account of its history and workings may be of general interest. The system of land settlement introduced by Sir Harry Johnston has already been described in the Empire Survey Review (“The Surveyor and the Politician”, by H. B. Thomas, vol. ii, p. 28). 相似文献
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Abstract Introductory.—From time to time the question of the relation between the metre and the foot is raised, most frequently perhaps from Africa. Had there been no more than a single metre to consider the question would no doubt arise but seldom: the most recent authoritative comparsion would be generally accepted. But actually it is the existence of two metres—the “ legal” and the “international”—which complicates the question, so much indeed that there is no metrological factor which has influenced survey, British and foreign, more than the relation between these two metres. The question was discussed in this Review (I, 6, 277, 1932), but memories grow shorter, attention is more diffused, and besides there is required a more explicit statement of the situation as it affects British surveyors, especially in Africa, whence the question has been raised anew. To illuminate it, unfortunately the need recurs to repeat some well-known facts. 相似文献
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《测量评论》2013,45(13):386-391
Abstract The International Population Union.—In 1927, as President of the Geographical Association, it was my duty to deliver an address to the Association. I chose as my subject “Population and Migration” with special reference to the English-speaking peoples. One result of the publication of this in Geography, the journal of the Association, was that I was invited to attend the World Population Conference, which was held at Geneva in August-September 1927. The Conference was a very interesting affair. It was organized, and largely paid for, by Mrs. Margaret Sanger. About twenty-four countries were represented. The late Sir Bernard Mallet presided, and in one of his speeches, winding up the Conference, he truly said that we might “congratulate ourselves on having shown the world that population questions, which bristle with controversy, political, moral, and religious, can be discussed by sensible people without animosity or unseemly wrangling”. 相似文献
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AbstractI. 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. 相似文献
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《测量评论》2013,45(12):329-330
AbstractMajor Hotine (E.S.R., No. II, pp. 264–8) still finds the location of a reference spheroid to offer insuperable difficulties. I confess that my difficulty is to see his! In my previous article (E.S.R., No. 8) at the foot of page 76, I used the word “coincidence” in error for “parallelism”. This harmonizes the article and I am glad that Major Hotine has directed attention to the error. 相似文献
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《测量评论》2013,45(74):155-161
Abstract60. The three standard or field reference tapes are stored at the N.P.L., Teddington, and standardised to class “A” accuracy immediately before and after each base measurement. In order to reduce the residual contraction or “creep” of in var when exposed to higher temperatures, the tapes are retained for as short a time as possible in the Sudan and since 1945 they have been transported in both directions by air. In this way, any “creep” should be revealed by the standardisation after a measurement. From the formula of Dr. Guillaume the ultimate shortening, in the temperatures prevailing at Meheisa and Husheib, would have been ?26 and ?20 × 10?5 ft. respectively and it is clear from Table 3 that this tiresome source of uncertainty is largely eliminated by the procedure adopted. 相似文献
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《测量评论》2013,45(12):345-346
AbstractIn 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. 相似文献
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《测量评论》2013,45(61):267-271
AbstractSome publications that have dealt with the question of convergence of meridians seem, to the present writer, to be clouded with misconception, and these notes are intended to clarify some points of apparent obscurity. For instance, A. E. Young, in “Some Investigations in the Theory of Map Projections”, I920, devoted a short chapter to the subject, and appeared surprised to find that the convergence on the Transverse Mercator projection differs from the spheroidal convergence; the explanation which he advanced can be shown to be faulty. Captain G. T. McCaw, in E.S.R., v, 35, 285, derived an expression for the Transverse Mercator convergence which is equal to the spheroidal convergence, and described this as “a result which might be expected in an orthomorphic system”. Perhaps McCaw did not intend his remark to be so interpreted, but it seems to imply that the convergence on any orthomorphic projection should be equal to the spheroidal convergence, and it is easily demonstrated that this is not so. Also, in the second edition of “Survey Computations” there is given a formula for the convergence on the Cassini projection which is identical, as far as it goes, with that given for the Transverse Mercator, while the Cassini convergence as given by Young is actually the spheroidal convergence. Obviously, there is some confusion somewhere, and it is small wonder that Young prefaced his remarks with the admission that the subject had always presented some difficulty to him. 相似文献
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《测量评论》2013,45(9):163-166
AbstractThe survey of Sierra Leone was fortunate enough to be completed just in time before the economic blizzard (if I may be permitted a well-worn journalistic cliché) descended on West Africa in common with the rest of the world and largely curtailed such activities. I do not propose to deal here with its technical side to any great extent. An excellent account of bush surveying is to be found in the “Handbook of the Southern Nigerian Survey”, which account always filled me with the greatest awe and respect for the men working there, their output being vastly greater than anything we were able to achieve in Sierra Leone. Truly “there were giants … in those days”. 相似文献
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AbstractThe majority of readers are doubtless aware of the masterly summary of the “History of the Calendar,” written for the Nautical Almanac for 193I (pp. 734–747) by Dr. J. K. Fotheringham. Most are probably also aware that the question of Calendar Reform has been considered by the League of Nations. At the Conference on Communications and Transit of 1931, October 19, the League adopted a resolution recommending a fixed Easter, but declared that “the present time is not favourable … for considering … a reform of the Gregorian calendar.” For information on the various measures of reform proposed at Geneva the works noted below may be consulted. In the meantime, pending the coming of reform—for come it will—readers may desire to.have a summary history of the question, with a statement of a solution which is of somewhat the same nature as others which have been proposed. 相似文献