A little book on map projection

Prefatory Note

BY

JOHN ADAMS, M.A., B.Sc, LL.D.

PROFESSOR OF EDUCATION IN THE UNIVERSITY OF LONDON

No kind of apparatus is more generally used in schools than maps. It is therefore essential that the teacher should understand how maps are made. Too often pupils accept maps merely as a part of the nature of things. Occasionally, they observe that the shape of a country or a continent varies from map to map, and the more thoughtful among them appeal to the teacher for an explanation. Accordingly mapprojection ought to be included in the training college course. As a matter of fact it formed part of my course as a student in training, and I have a vivid memory of the difficulty of the subject as presented to me in a certain crabbed text-book.

College would have been a pleasanter place for me and my fellow students had we been able to use Miss Adams' little treatise. She begins at the beginning: she takes time to present her matter : she uses all manner of concrete illustrations : she appeals constantly to the reader's experience : she does not shirk difficulties but she reduces them. Her approach is psychological. She is more concerned to present facts in such a way as to meet the pupils* needs than she is to maintain the logical symmetry of the subject matter. Her work is accordingly of a special value to professional teachers, and I can confidently recommend it to my fellow workers in the Training Colleges.

It may not be out of place to mention that, though we bear the same surname. Miss Adams and I are in no way related. I have never met her, and know nothing of her except what I have learned by reading her book.

JOHN ADAMS.

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AUTHOR^S PREFACE

This little book is intended for the use of pupils in Secondary Schools, Central Schools, Higher Elementary Schools, and the Senior classes of those ordinary Elementary Schools in which special attention is given to practical geography. Apart from the Appendix, except in one paragraph which is not essential, no knowledge is assumed of even the Trigonometrical ratios. In the Appendix a few examples are given of the application of higher mathematics to map projection.

The writer is indebted for much information to the work on Map Projections by Arthur R. Hinks, M.A., F.R.S. (Cambridge University Press, 1912). The student who desires to calculate map projections other than those of the simplest type, or to estimate the errors of scale or form in any map, should study Mr. Hinks' book. The object of the present writer is description rather than calculation and, except for the" sake of illustration in the Appendix, only the simplest calculations have been used.

A special feature is that all the projections, except Fig. 15, are drawn to the scale of a globe two inches in diameter, which differs from the scale of i : 250,000,000 by only one quarter per cent. The projections are, therefore, directly comparable one with another.

The reader is advised to draw the projections contained in this book, or parts of them, to the scale of the school globe and to compare the meridians and parallels with those on the globe for different latitudes and longitudes.

A few illustrations have been introduced from mechanics, physics, and geometry, which may appear to have but a very remote connection with geography, but they will afford subjects for lessons which will appeal to many pupils, and lead to an increased interest in map projection. It is very undesirable that the subjects of school study should be separated by "water-tight bulkheads.'*

M. A.

Forest Hotel,