ADVERTISEMENT. In the Press, and shortly will be published, PART II. OF GORDON'S MARINE BOARD CATECHISM, Containing Answers to the Deviation Questions in List B of Circular No. 517. ALSO The New Time Azimuth Problem. To be followed by Answers to the Questions in the Liverpool Syllabus, or Circular No. 414 for Masters-Extra. CATECHISM FOR THE MARINE BOARD EXAMINATIONS, CONTAINING THE REQUISITE ANSWERS TO THE QUESTIONS ISSUED BY THE BOARD OF TRADE. IN TWO PARTS. PART I. ANSWERS TO THE DEFINITIONS IN LIST A, CIRCULAR No. 517; ALSO THE NEW ABC RULES OF NAVIGATION. BY J. GORDON, A. M., Author of several Nautical Works, including "The New Lunar and Time Tables," for which Grants were given, viz., MORDEN COLLEGE, BLACKHEATH, S. E.; AND SOLD BY ALL NAUTICAL BOOKSELLERS. 1872. PREFACE TO PART I. BEING the first of our living Authors who have written Guides or Manuals to assist Candidates in preparing for their Examinations at the Local Marine Boards (which Guides were favourably received by the Nautical profession), I have been requested by several Nautical Teachers of my acquaintance to publish a small work elucidating the alterations in the Examinations which have been lately introduced by the order of the Board of Trade. Consequently I have composed this Catechism, thinking that it will be useful to Candidates in preparing to pass their Examinations. There are several excellent Guides in use, which contain Rules for and Exercises on the Nautical Problems prescribed at the Examinations; but as these were composed by their Authors entirely for the old forms of the Problems, this Catechism will be found a useful auxiliary to such Guides; and I trust will be approved of by Teachers, as it will save them the trouble of forming new Exercises. I have introduced a new set of Rules, termed A B C, for the sake of reference, which will enable learners to acquire clear ideas as to when they should add and when they should subtract; also how to name the result. I have, therefore, suggested that a change in the direction of the Compass needle, such as Variation (Var.) for the N. point, should be called Reversed-Variation (Re-Var.) for the S. point. This is strictly true; whereas to say that Var. is E. for the N. point of the needle, and also E. for the S. point of the same needle, is decidedly untrue: in the latter case we call it Re-Var. or W. By adopting the simple and correct principle of calling things by their right names, all difficulty disappears. J. GORDON. MORDEN COLLEGE, BLACKHEATH, S. E., LONDON, 1st May, 1872. |