Sir George Deacon, F.R.S., a past president, has recently written a most persuasive case for founding a Chair in Navigation. He mentions Sir Isaac Newton's insistence that Christ's Hospital should teach ‘not only what is necessary to make a mariner skilful in his ordinary road, but also what would assist him to invent new things and practices and to judge what comes before him’. It was in this spirit that a basic analysis of navigation was begun some years ago although it was not expected that Sir Isaac Newton's great conception would be realized. Indeed, the object was only to try to suggest to educators the potential of navigation as a scientific discipline.

Elements of the work dealing with probability and with information theory have already appeared in the Journal and certain ideas have been crystallised into patents taken out by Smiths Industries Limited. Other results are presented here in a condensed form starting with a definition which leads on to a pattern of equipments by using a particular development of dimensions and which highlights the special difficulty of collision avoidance. Linkages between gimballing error, precession and coriolis effect are suggested, and the significance of frames of reference is emphasized, suggesting a unified approach to the trigonometry needed by the navigator. If these crude tools can be tempered by the fire of criticism or replaced by finer cutting edges, the effort will not have been wasted.