In the bicentenary year of the birth of Matthew Flinders at Donington, near Boston in Lincolnshire, it is my privilege to present to Members of three notable British societies some details of the life and work of this great hydrographer.

His surveying and charting impact was made entirely in Australian waters and he is probably better remembered in that country today than he is in his homeland. It is my hope that my discourse, added to the many activities that have been arranged in Britain this year, will do something to rectify this situation. My talk will attempt to tell the brief story of Flinders' 40 years of life and work, beset in his later years by many misfortunes. I will also examine in some detail how Flinders conducted his surveys by taking a few isolated examples, and finally briefly review the results of his labours.

The object of any kind of marine radar plot when ships are in fog is to synthetize as much data on the current traffic situation as affects or will affect the safety of own ship and so to produce a plan picture of the area around the ship and the vessels moving on it, more or less as it would appear to the eye in clear weather. The plot will be expected to show, not only the current position of each ‘target’ vessel, but also the expected forward movement of each and the risk of collision which this involves.

The word synthetize is used because it so completely implies the building up of separate elements of information into a whole; in this case, a continually changing whole. The word whole is also worth emphasizing, because only if the situation is so presented can the mariner appreciate the form which its development is taking both between own ship and those target ships which present a direct threat and between target vessels whose mutual evasive manœuvres may indirectly endanger own ship. The needed synthesis cannot be attained unless the predicted future positions of target ships are coordinated in time, so that the relative positions at the future time may be compared with the current relative positions.

This paper, by the head and the deputy head of the Civil Marine Navigational Aids Division of the Admiralty Surface Weapons Establishment, deals with certain problems relating to the proposed Channel Navigation Information Service, including radar coverage, the transmission of information, computer assistance and information display. The paper was read at a meeting of the Institute held in London on 30 January 1974 with the President in the Chair.

Much of the background to marine traffic problems in the Dover Strait has already been discussed in previous issues of this Journal. It was decided in 1971 that some radar surveillance of the area would be appropriate. The first steps were taken when a radar trial was conducted by A.S.W.E. in the St. Margaret's Bay area near Dover in 1971. As a result of these trials the Coastguard station at St. Margaret's was fitted with a standard marine radar as an interim solution.

A practical traffic control system can be envisaged as a hierarchy of control loops, each serving to convert a traffic demand into a potential traffic flow. Each loop is concerned with problems that can be foreseen to arise at some time in the future and the distinctive characteristic of any loop is the distance ahead, in time, to which it prognosticates. Although this model is probably applicable to most traffic systems the present note will apply it in the context of air traffic control.

Figure 1 shows a whole family of possible control loops. (Not all of these are present in all A.T.C. systems.) In each loop there is a mechanism for the prediction of future traffic. This prediction is compared with certain internal criteria and, if these are not satisfied, some control action is taken to coerce the traffic pattern into some more acceptable form. It is characteristic of most of these loops that they cannot be proved to be capable of safely handling all conceivable traffic demands; there is an implicit assumption that the superior elements of the control system will not tolerate a traffic demand which is beyond the handling capability of the inferior loops, but that a residue of unsolved problems can generally be left to be handled further down the chain.

Airborne computing has been with us since the very early days of aviation when it comprised such basic calculations as TAS from the observed parameters of IAS, temperature and altitude. The display requirement for this type of computing was virtually negligible. However it was appreciated that where instruments could take over the repetitive processes of navigation the aviator could devote his time to tasks which he could perform better than the machine, calculations which he could perform more speedily or more economically than the technology of the time made possible and those which required the intuitive reasoning which has always made navigation a combination of art and science. The Air Position Indicator is an example, and its logical extension the Ground Position Indicator. These analogue computers not only freed the navigator from a great deal of repetitive work but provided a consistent accuracy, and some limited tactical flexibility. The demand for display was still small and easily accommodated in the relatively uncluttered crew positions in early aircraft. As aircraft systems became more complex and speeds increased, the increased workload meant that the crew were not capable of accepting all the information from the increasing number of sensor displays and calculating position, heading to fly, E.T.A., fuel state, and so on, with sufficient rapidity for the required accuracy to be maintained. With the aircraft coming into service it was also necessary to consider optimum altitude and minimum-fuel flight paths.

Modern digital computers are well known to be extremely fast and accurate, but another attribute which is even more vital in the role of nerve centre to a modern nav./attack system is flexibility. The ground-based computer that carries out a different task every day of the week is now normal, but even in a military aircraft the computer is called upon to fulfil several roles: on the ground analysis and diagnosis, in the air navigation and weapons delivery, and often as flight director computer if the situation demands. Because of its characteristics of carrying out the computations serially in a central processor, a single decision point can alter the whole characteristics of the program; a single switch could make the computer carry out a fault diagnostic program or the navigation/attack program. By the action of one switch the meaning of every other switch and display can be altered. It is this characteristic above all that calls for special displays if full advantage is to be taken of the flexibility in the main computer interface.

The objective of this paper is to show that an underwater navigation system can be developed that is technically and economically feasible and of high reliability for long distance under-ice operation. Recent advances in underwater navigation for cruise, exploration and search and rescue operations are considered and applied to the current interest in Arctic waters, where mineral prospecting and oil transportation are potentially important.

The paper was read at a meeting of the Institute held in London on 27 February 1974 with F. A. Haworth in the Chair. Mr. Cestone is from the Naval Ships Systems Command of the United States Department of the Navy; Mr. St. George from the Charles Stark Draper Laboratory of the Massachusetts Institute of Technology.

This paper by the Vice-President of the Netherlands Ship Model Basin presents the results of a study performed on the N.S.M.B. ship manœuvring simulator aimed at the development of criteria for the manœuvrability of ships sailing in a current. Six pilots navigated four types of 250,000 d.w.t. tankers in sixteen different conditions of current.

Ships have grown so large that it is no longer taken for granted that they can be manoeuvred as required. The problem can be split up in two aspects, the ship's inherent manoeuvring ability, which is mainly a technical problem, and the mariner's ability to manœuvre the ship, which is mainly a psychological problem.

This paper, based on a presidential address given to the British Section, Société des Ingénieurs Civils de France on 11 January 1974, examines the state of sea transport today and proposes a European Maritime Agreement along the lines of the Chicago convention for Civil Air Transport.

The following definitions may be agreed.

Channels all natural or artificial beds of rivers, estuaries or other bodies of water, or a body of water joining two seas, for example the Channel joining the North Sea with the Atlantic Ocean. The word also means ways of access or communications and methods of conveying nonmaterial things, such as in radio and radar systems.

Proper means fit, suitable, efficient and safe; a secondary meaning is correct according to rule and accepted custom.

This paper discusses navigation tables based on the decomposition of the astronomical triangle into two right-angled spherical triangles by a great circle arc extending from the zenith to the meridian of an observed celestial body. In a recent fairly comprehensive study of some thirty short-method tables in which the division of the PZX-triangle forms the principle of construction, nineteen are of the species to be discussed.

Following the introduction in 1871 of the first short-method table by Thomson, some twenty years were to pass before any real advance was made in this field. Thomson's table was in fact re-issued by Kortazzi in 1880 and by Collet in 1891, in modified forms, but it was Professor F. Souillagouët of France who is to be credited for introducing something novel and decidedly better than Thomson's table. Unlike the earlier ones it was designed specifically for the Marcq Saint Hilaire method of sight reduction and, in contrast to Thomson's table which was based on the division of the PZX-triangle by a perpendicular from X, Souillagouët's was based on division by a perpendicular from Z.