THE YEAR 1934 IN NIGERIA

Abstract

The year has been made noteworthy by the decision of Government to amalgamate the Land and Survey Departments under the direction of the Surveyor-General with the title of Commissioner of Lands and Surveyor-General. As the fusion of the two Departments took place only towards the end of the year, this report covers only survey activities for the year 1934.     

A FIFTY-YEARS RETROSPECT

Abstract

On returning from India I was posted to the command of a depot company at Chatham, a kind of employment which has the advantage of giving one who has been serving in the East a complete change of ideas. The life was pleasant enough, though the duties were mainly of a routine nature. I was not sorry after a year of this agreeable enough life to be given a further change in the shape of special employment on the West Coast of Africa.     

THE HYDROGRAPHIC YEAR, 1933

Abstract

During the past year H.M. Surveying-ships have been employed in various parts of the world, four in Home Waters and four on Foreign Stations.     

THE YEAR 1933 IN NORTHERN RHODESIA

Abstract

The general depression in world trade has affected the country to no small extent during the year in almost all branches of departmental activity. It has been particularly reflected in the Survey Department by a reduction in applications for land from new settlers, and in subdivisional surveys· carried out for private landholders. In all other branches, however, the Department has had more on its hands than its now limited staff could cope with, and there is the danger of work getting behindhand and being put aside for a future occasion whilst new projects are dealt with to supply immediate requirements.     

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.     

GRID BEARINGS AND DISTANCES ON THE CONICAL ORTHOMORPHIC PROJECTION

Abstract

When computing and adjusting traverses or secondary and tertiary triangulation in countries to which the Transverse Mercator projection has been applied, it is often more convenient to work directly in terms of rectangular co-ordinates on the projection system than it is to work in terms of geographical coordinates and then convert these later on into rectangulars. The Transverse Mercator projection is designed in the first place to cover a country whose principal extent is in latitude and hence work on it is generally confined to a belt, or helts, in which the extent of longitude on either side of the central meridian is so limited as seldom to exceed a width of much more than about 200 miles.     

THE YEAR 1930 IN NORTHERN RHODESIA

Abstract

The year 1930 in Northern Rhodesia has been particularly busy for the Survey Department. This was chiefly due to the mining activity in the northern area and to the rapid development of new townships and the expansion of old, owing to the large influx of traders and business houses. The staff has been augmented; but, although the office accommodation has improved, we still find ourselves somewhat cramped at headquarters, especially when the local field staff returns there during the rains. A general review of the instruments and equipment has been made, resulting in the scrapping of old and obsolete material and its replacement by modern equipment. In this connection it is interesting to note the general adoption of the new Zeiss, Wild and Tavistock theodolites.     

Searching for the ‘Right’ Legend: The Impact of Legend Position on Legend Decoding in a Cartographic Memory Task

ABSTRACT

Map legends are key elements of thematic maps and cartographic communication. The question of how to style map legends is a topic which has often been addressed by cartographic academics and practitioners. Nevertheless, the question of where to position a map legend has only hardly been discussed. Principles of cognitive sciences allow the assumption that a legend positioned to the right of a map field can be read and decoded faster than a legend on the left side. This study investigates the impact of legend positioning on legend decoding. It involves an experiment based on a recognition memory paradigm and the registration of eye-movements. The results show that, in less time, a legend positioned to the right of the map field (compared to a left legend) can be decoded faster. The same accuracy of a cognitive representation of geographic space can be achieved in spatial memory.     

Modelling of land use land cover change using earth observation data-sets of Tons River Basin,Madhya Pradesh,India

Abstract

An integrated Markov Chain and Cellular Automata modelling (CA MARKOV), multicriteria evaluation techniques have been applied to produce transition probability. The unsupervised method was employed to classify the satellite images of year 1985, 1995, 2005 and 2015 to meet the magnitude of LULC change. Results showing the spatial pattern of the sub-basin is largely influenced by the biophysical and socio-economic drivers leading to growth of agricultural lands and built-up area in the basin. Simulated plausible future LULC changes for 2025 which is based on a CA MARKOV that integrates Markovian transition probabilities computed from satellite-derived LULC maps and a CA contiguity spatial filter (5 × 5). Further, the fragmentation analysis was performed to check the fragmentation scenario in the year 2025. The result for year 2025 with reasonably good accuracy will be useful to the planners, policy- and decision-makers.     

THE YEAR 1935 IN NIGERIA

Abstract

This report covers the period of the first full year since the amalgamation of the Land and Survey Departments under one administration. The general scheme of amalgamation to which reference was made in the report of the Survey Department for 1934 has functioned satisfactorily and calls for no particular comment.     

THE SURVEYOR's PYTHAGORAS

Abstract

DURING the course of his work a surveyor often has to solve a right-angled triangle in which one side is very small in comparison with the two others. As the orders of magnitude of the sides in such a triangle differ so widely, a simplified formula can be substituted for that of Pythagoras.     

THE YEAR 1932 IN NIGERIA

Abstract

The general organization remained the same as during the last few years, but owing to the reduction last year by 32 per cent. of the European and by 8 per cent. of the African-personnel the output of cadastral and topographical work was considerably lower. Against this, however, there have been increased activity and larger output from the drawing and lithographic sections.     

THE HYDROGRAPHIC YEAR 1930

Abstract

For some years past the work of the Hydrographic Service of H.M. Navy afloat has been carried out by eight of H.M. Surveying Vessels. These ships, of which four are employed abroad and four in home waters, work at sea for about eight months in the year and are refitted during the remaining four months, usually during the winter or bad-weather season. Whilst the ships are being refitted for further service the officers are employed in drawing the fair charts of the season's work and in preparing Sailing Directions and other work in connection with the Survey.     

On the night errors in astronomical determinations

Summary The discrepancy between precision and accuracy in astronomical determinations is usually explained in two ways: on the one hand by ostensible large refraction anomalies and on the other hand by variable instrumental errors which are systematic over a certain interval of time and which are mainly influenced by temperature.In view of the research of several other persons and the author’s own investigations, the authors are of the opinion that the large night-errors of astronomical determinations are caused by variable, systematic instrumental errors dependent on temperature. The influence of refraction anomalies is estimated to be smaller than 0″.1 for most of the field stations. The possibility of determining the anomalous refraction from the observations by the programme given by Prof. Pavlov and Anderson has also been investigated. The precision of the determination of the anomalous refraction is good as long as no other systematic error working in a similar way is present.The results, which are interpreted as an effect of the anomalous refraction by Pavlov and Sergijenko, could also be interpreted as a systematic instrumental error. It is furthermore maintained thatthe latitude and longitude of a field station can be determined in a few hours of one night if the premisses given in [3, p.68]are kept. It has been deplored that the determination of the azimuth has not been given the necessary attention. It is therefore proposed to intensify the research on this problem. The profession has been called upon to acquaint itself better with the valuable possibilities of astronomical determinations and to apply them in a useful and appropriate manner. At the same time, attention has been called to the possibility of improving astronomical determinations with regard to accuracy as well as effectiveness.     

EXPANSION OF PAPER AS AFFECTING BEARING

Abstract

The problem of the influence of the paper itself on bearings taken off maps or plans has been recently discussed by G. T. M. in this Review (iii, 22, 479). The following alternative method of solving the problem may be of interest; the same figure and symbols are used as in the article mentioned.     

REPORTS. THE YEAR 1934 IN CEYLON

Abstract

The Ceylon Survey Department is gradually returning to its normal activities after the period of depression. The programme of work is again being increased as the demand for survey work grows with returning prosperity in the Colony. The Survey Department Training Classes have been reopened for training new recruits to fill the vacancies in the upper and lower grades which have been left unfilled during the retrenchments. It takes a year, however, to train a subordinate office: and two years to train a probationary Assistant Superintendent, Including one year at Cambridge. Recruiting is consequently rather. a slow process, and it will be some years before the Department is again at full strength, as there are now 27 vacancies in the Field Staff and 34 in the Office Staff to be filled, out of a total of 705.     

TRIANGULATION: BEARINGS VERSUS ANGLES

Abstract

There has always been a marked difference of opinion on the relative merits of the methods of bearings and of angles as applied to triangulation, though it is probable that the majority of writers prefer the method of bearings for first-order work. The subject was mentioned in a recent issue of this Review (vii, 47, 19).     

SARAWAK LANDS AND SURVEY DEPARTMENT

Abstract

Financial.—The revenue collection for the year was 479,591.75, consisting of Lands and Survey Revenue 356,087.52 and Mining Revenue 123,504.23.     

SARAWAK LANDS AND SURVEY DEPARTMENT, 1940

Abstract

Financial.-The revenue collection for the year was 440,790.30, consisting of Land revenue 336,422.97 and Mining revenue 104,360.33. The expenditure for the year was 206,476.02, of which only 192.05 was Special. This does not include salaries, amounting to 14,313, of Officers seconded for Food Control. Expenditure was again below normal because of the secondment of staff to other duties.