PREFACE. HAVING found, from experience, that the majority of Guide or Hand Books to the Local Marine Board Examinations are too copious and extensive, I have endeavoured in this publication to embrace, in as small a compass as possible, all those subjects which are necessary to be understood by Candidates before presenting themselves for examination. The whole of the Questions in the Twelve Papers, given at pages 24 to 47, are solved by NORIE'S EPITOME, that work being principally used by seafaring men; but I may remark, that I perfectly agree with a friend of mine, that there is too great a redundancy of Tables in NORIE, which has the effect of rendering Seamen careless and inaccurate, trusting too implicitly to extraneous assistance, and thus the object is defeated which the Board of Trade has in view, namely, that they shall be able to compute for themselves. In finding the true Altitude from the observed Altitude of the Sun's lower limb, NORIE'S Table IX has been used, which reduces the whole of the corrections into one, and which will be found to be within a very few seconds of the truth, and sufficiently accurate for all practical purposes. The Rules, as well as the Blank Forms, of the different Problems, are given in order to show the pupil at once the form and the formula used in the solution of each Question. I have not given any Courses to be corrected for deviation in the Papers; but to supply the deficiency, there are a few examples at page 48, which will suffice if the pupil can solve A few Exercises on the Charts, for Masters and Mates, will, I think, prove useful. The Bearings and Distances of the principal Headlands, as well as those of the Lights, are taken from the Piloting Directions for the East Coast of England and the English and Bristol Channels, books which are indispensable to navigators in the British Seas. To each of the Questions in the Papers are added the different parts of the solution, so that the pupil may more readily detect any error in the course of his work, before he arrives at the final answer. I hope that this little volume will, in some measure, accomplish the object for which it is intended, namely, to be a guide to mariners desirous of acquiring a sound knowledge of navigation, which is essential to advancement in their vocation, and to which so many of our seafaring friends in the present day direct special attention. I would, in conclusion, recommend to them perseverance in their studies, remembering the exhortation, "Whatsoever thy hand findeth to do, do it with thy might." LONDON, JULY, 1859. THE AUTHOR. |