The fourth Duke of Edinburgh's Lecture was presented by Professor P. M. S. Blackett, C.H., P.R.S., at the nineteenth Annual General Meeting, held in the Royal Geographical Society's house on 27 October 1965, with the President in the Chair. The President introduced the lecturer as one of the most eminent physicists of our time. Over the last thirty years he had held a number of very distinguished appointments, and was until recently Professor of Physics at the Imperial College of Science and Technology. He is now deputy chairman of the Ministry of Technology's Advisory Council. In 1948 Professor Blackett was awarded the Nobel Prize for Physics. A summary of the main points covered is given below.

The purpose of this article is to describe the new tables, with the above title, which are shortly to be published by the U.S. Naval Oceanographic Office as H.O. Pub. No. 229.

Historical Survey. The most comprehensive tables designed for the application of the intercept method of plotting position lines in the practice of astronomical navigation at sea are the well-known Tables of Computed Altitude and Azimuth, originally published in the years 1936–1945 as H.O. Pub. No. 214 by the U.S. Navy Hydrographic Office (as it was then called). These are by no means the earliest of such tables in concept and objective, for Lord Kelvin, generally considered the father of modern navigation methods, expressed interest in tables from which solutions could be extracted direct; he recognized, however, that the tabulation of 903 × 603 or 157,464,000,000 solutions, which would be required to avoid interpolation, was quite impracticable.

In 1766 Nevil Maskelyne, fifth Astronomer Royal, compiled and published the first edition of The Nautical Almanac and Astronomical Ephemeris, designed to make practicable the determination of longitude at sea by the method of lunar distances. To mark the occasion of the two-hundredth anniversary of this event the staff of H.M. Nautical Almanac Office presents an objective assessment of the method of determining longitude by the measurement of lunar distances, in terms of modern knowledge, outlook, notation and computing facilities.

Reference to contemporary publications has been deliberately avoided; the story of the development of methods and techniques for the observation and reduction of lunar distances requires, and deserves, a separate study.

In 1961 the Institutes of Navigation in Great Britain and France, with the Deutsche Gesellschaft für Ortung und Navigation, formed a representative Working Group to go into the question of regulating traffic in converging areas at sea with particular reference to the Dover Strait. The Group's Report, which was published in October 1962, made certain proposals for routing traffic in the area which were accepted, in April 1964, by the Maritime Safety Committee of the Inter-Governmental Maritime Consultative Organization.

The present trend in the automation of merchant ships may be compared with the situation which existed in aviation some thirty years ago when individual operators were developing their own ideas in navigation and flight programming, with little coordination and often a good deal of secrecy. In recent years some degree of automation has become usual in the design of new cargo vessels because of the need to reduce labour costs, and perhaps claims arising from accidents to personnel, as well as to increase efficiency of operation and reduce the margin of navigational error. But again there is the same lack of coordinated development and open discussion, in marked contrast to the planned development of the supersonic transport. In America, the U.S. Maritime Commission in cooperation with some of the instrument makers has carried out studies in ships' instrumentation, and also on cargo handling and machinery automation; but owners have remained aloof, following their own lines of development.

Capitaine de Frégate Oudet's paper was presented at an Ordinary Meeting of the Institute held at the Walker Art Gallery in Liverpool on 20 May 1966, with the President in the Chair. The paper was, in the absence of its author, read by the Executive Secretary who also summarized for the meeting the report of the Working Group on Traffic Separation at Sea (see p. 411).

In December 1962, at a meeting of this Institute, I gave an account of the work that had led to the adoption of one-way routes for the Dover Strait. I now have the honour of describing the balance of work effected since that time, or more exactly, since the Eastbourne conference where the decision was made to carry on the organization of converging areas.

Dr. David Lewis, after completing the single-handed transatlantic race in 1964, sailed his catamaran Rehu-Moana through the Magellan Strait to Valparaiso and on to Easter Island and Tahiti. From Tahiti he sailed to New Zealand.

In an earlier paper published in the Journal (17, 278) Dr. Lewis reviewed the background to and evidence for various theories about early Polynesian navigation. One of his conclusions was that they must have been able to determine both course and, in effect, latitude with sufficient accuracy to make a landfall within the area of known groups of islands and so to proceed to any intended destination. This paper aroused considerable interest and was the subject of numerous contributions to the Journal, in particular from Andrew Sharp (18, 244) and Brett Hilder (18, 246).

In a series of communications written on board during the voyage to Tahiti, Dr. Lewis discusses the objections raised to some of his hypotheses. These cannot be dealt with here. On the voyage from Tahiti to New Zealand, via the Cook Islands, however, Dr. Lewis attempted to demonstrate, by navigating without instruments, that the methods used by the ancient Maoris were sufficiently accurate to make the voyages attributed to them navigationally feasible. It is this voyage that is related here.

Of all man-made objects, satellites are unique in their ability to ‘see’ large regions of the Earth at one time. Because of this ability, they can serve as relays to provide the advantages of line-of-sight communications between widely separated points on the Earth. They have another useful characteristic also—their locations in space can be determined to high accuracy, hence they can be used as position references for navigation or surveying.

The Rules for Navigation were established originally by custom and prudence some 400 years ago, but they were not presented in a codified form until 1863. Since then they have been modified several times, with the most recent modification becoming effective in September 1965.

The Rules apply to all British ships, together with those belonging to signatory countries of the International Conference on Safety of Life at Sea, 1960. They apply also to all ships navigating within British territorial waters, but, in areas governed by local rules, they serve to supplement not to override those local rules.

The remarkably successful development in recent years of inertial navigation systems suggests a reconsideration in this light of the phenomenon of animal navigation, the physiological basis of which has not been fully established. Some of the aspects of inertial navigation which may be particularly relevant to possible biological analogues are considered. Aspects of animal navigation and orientation that are particularly suggestive of inertial navigation are also treated. The physiology of the biological sensory mechanisms that could form the sensing elements of the biological inertial systems are outlined. Some suggestions are advanced for further investigations.

In the first part of this series of papers an outline was given of the approach made at the Royal Aircraft Establishment to the problems of estimating collision risk and of specifying the quality of navigation needed to make separation standards safe. It was stressed that estimates should be based on intensive observation of flying errors, rather than on speculative theories, and that it is more feasible to develop ‘upper limit’ estimating techniques than those which purport to give the exact risk. In summary, a list of seven ‘requirements’ was given, as a reminder of the essential principles which can so easily be overlooked in the piecemeal task of relating separation standards to collision risk.

The purpose of this paper is to show some of the theoretical techniques which have been developed at R.A.E. to satisfy five of these requirements. (The remaining two do not call for special techniques and will be dealt with when practical applications are described in Part III.) The paper contains three Appendixes, dealing with the frequency of losing separation in one dimension, the computation of P's from the assumed tail shapes, and the treatment of relative errors. These are not included here but will appear in the off-printed version which may be obtained from the Royal Aircraft Establishment.

Both this paper and the paper that follows by Mr. Attwooll are crown copyright and are reproduced with the permission of H.M. Stationery Office.

1. Types of presentation. The choice of the method of presentation used by a radar operator is probably the most important of the various alternatives open to him for the most effective keeping of his watch, because they are all different, each has its advantages and limitations and one of them may be best suited to the circumstances and to the mentality of the observer himself. In what follows, the anti-collision use is principally in mind.

This paper gives a general picture of the use of electronic aids in the British fishing industry and describes experimental and development projects now in hand. Some of the problems involved have so far defied solution because of technical or economic difficulties. Although much of this work is not directly concerned with navigation some navigational problems are involved, and these aspects of the fishing industry may be of general interest.

The Fishing Industry in Britain. The British fishing industry is divided into two main sections, the white fish industry and the herring industry. Between them they account for a total annual catch of approximately 800,000 metric tons which realizes at first sale, that is on the quayside, approximately £50 million. Of this total the herring industry accounts for about 15 to 20 per cent by weight. It is in the other section, the white fish industry, that I have been engaged for the last three years or so and this paper therefore deals mainly with electronic problems and developments in the white fish industry.

The Imposing structure of modern science and technology is a triumph of man's endeavour, and the story of its development, at last being closely investigated by the scientific historian, is gradually being unfolded. It is largely with the flowering of the practical mathematical arts, out of which modern science and technology have sprung, and with special reference to the English scientists, technologists, practitioners and teachers who collectively made this possible, that Professor Taylor writes in her latest book The Mathematical Practitioners of Hanoverian England.

In the first of this series of papers, the general principles of costing the effect of air traffic control deviation were discussed. This paper discusses the application of these principles to a model route structure for North Atlantic subsonic jet traffic. It is shown how the, design of an optimum system is related to cost considerations and how the cost depends on variations in traffic intensity and on the level of separation standards in all three dimensions. The work on which the paper is based was carried out at the Royal Aircraft Establishment.

In various papers published recently in the Journal and elsewhere, examples have been given in which the theoretical normal or gaussian distribution of errors does not correspond closely with the distributions found in practice; in particular the frequency of large errors is commonly underestimated by the normal law of errors. This discrepancy is discussed by Anderson who suggests that an exponential distribution may give a more realistic estimate of the frequency of large errors. A closely associated problem is that of determining the frequency distribution of the largest values occurring in a number of samples taken from some parent population. This problem has been solved theoretically for an important class of distributions and it is the object of this article to draw attention to this work and to show how it can be simply applied to practical problems, albeit in a rough and ready manner, without going far into the statistical details with which the subject abounds.

1. Introduction. Nautical charts of many areas of the world carry notations adjacent to natural marine hazards such as ‘position doubtful’, ‘existence doubtful’, ‘position approximate’ and ‘reported (date)’. In spite of the development of precision survey and navigation systems, many of these notations must continue to be carried until the positions of the hazards are accurately determined or their existence disproved.

The expanse of the oceans obviously precludes costly systematic hydrographic surveys in all areas, particularly in remote offshore areas. Although international cooperation in the exchange of hydrographic information assists in meeting modern charting requirements, the task of charting the seas may never be complete.

Over the past few years, numerous papers have been written concerning various aspects of S.S.T. operations, the majority dealing with one or two facets. This short review considers those aspects which are of major importance when the S.S.T. is operated in non-optimum conditions and an attempt is made to indicate the relative cost penalty caused by the phenomena discussed, the performance in smooth standard conditions being taken as the datum. Little of the information presented is new and most of the points mentioned are considered in greater detail in the references. (Crown copyright, reproduced with the permission of H.M.S.O.)

The basic parameters leading to aircraft navigational error are combined statistically and are used to evaluate the uncorrected deviation (wander) to be expected in both subsonic and supersonic transport aircraft operating in a typical trans-oceanic environment. The size of the across-track and along-track wander before any form of corrective control is applied indicates the physical size of the A.T.C. block of airspace necessary to contain the aircraft. The variation of block size with the forward prediction period used by A.T.C. is presented graphically. The effect of improvement in the basic sources of error is demonstrated and it is seen that for the S.S.T. era attention must be turned to effecting improvements in aircraft heading and airspeed holding capabilities.

The Loran C radio position-fixing system has been described in technical detail at international conferences and elsewhere. This paper tries to convey the general ‘feel’ of the system and its characteristics and to indicate, with as few irrelevancies as possible, what sort of process makes the two readout counters go round and give the navigator his position fix. The equipment to which the paper refers is the AN/SPN-31 marine Loran C receiver, which was designed and produced by Decca to a U.S. Bureau of Ships specification. Individual makes of Loran C set differ in various ways, but SPN-31 will serve for illustrative purposes.