In his Presidential Address at the Annual General Meeting of the Institute, Captain Majendie spent some time on demonstrating the restrictions imposed on free navigation by air traffic control. Whilst there is much truth in his statement the matter does not end there and I believe that those who study his address in retrospect should remember that the marked inflexibility of economic operation in the vertical plane of the modern jet aircraft and, to a lesser extent, the turbo-propeller driven aircraft, imposes considerable restrictions on air traffic control! In fact, the designers of modern aircraft and engines seem to be doing their best to deprive air traffic of its unique asset—the third dimension.

Last summer I sailed in R.M.S. Newfoundland from Boston to Liverpool and took the opportunity of keeping up a navigational plot using a minimum of charts and instruments. The sextant I used was a box sextant and it occurs to me that some description of this instrument may be of interest to navigators. Box sextants are lightweight and usually have a sling case which enables them to be carried or packed away easily. They are much less expensive than the standard sextant, and since they are precision-made instruments will last just as long. Good results can be obtained with them both in coastal navigation and offshore.

H.M.S. Dryad's memorandum (Journal, 9, 444) speaks of ‘only those tables required’. But what this word ‘required’ does or should mean could be debated ad infinitum. The main division comes as between a set of tables intended to be an instrument of practical navigation and one intended to be an instrument of technical education, and the dividing line between the two would be a very blurred and disputable one indeed. My own set of nautical tables came into existence because I was convinced at the time that a set of tables, ‘streamlined’ for sea use was urgently needed, and in so far as logarithmic methods may be still used I still consider that my first edition was a better instrument of navigation than any of the four later ones. But whereas I knew that I wanted such a set of tables for my own use, and was of the opinion that everybody else did (or should), I became aware that I was in a comparatively minute minority. In fact it became slowly and painfully borne in upon me that something like 90 per cent of all navigators would use all their sea-going lives the tables they were first taught on. This meant that I had to consult the schools and examining authorities and include all their academic needs, and so my streamlined volume soon began to develop a corporation. I did, of course, try again with my Four-Figure Navigation Tables, but that is another story.

Since the advent of radar, the need for correct interpretation has become only too clear from the record of so called radar-assisted collisions. The practical navigator has been shown various methods of noting PPI data and solving the problem of how best to avoid collision. We have the practical system of plotting, either with ship's head or true north upwards. We are now being offered some ingenious graphs and tables by Captain Wylie, Mr. Slater and others (Journal, 9, 161, 448). The navigator has an opportunity to study these methods and use them at sea, in clear weather, in conditions where he can assess the advantages of each method and also their accuracy.