1. Surveying with the Land-Chain and Plotting the Survey.

2. Traversing with Prismatic Compass and Chain.

3. Trigonometrical Surveying and Traversing with a Theodolite.

4. Military Sketching with Pocket-Sextant and Prismatic Compass, using the marching step of 30 inches for measurements..

5. Military Sketching without Instruments. 6. Levelling in all its branches.

In justice to other writers on Surveying, both civil and military, I shall here state what publications I have consulted during the preparation of the following pages. They are:-Adams's Essays; Outlines of a System of Surveying, &c., by Major Sir T. L. Mitchell; a Treatise on Practical Surveying and Topographical Plan-Drawing, by G. D. Burr, Esq., Professor of Military Surveying at the Royal Military College; Treatises on Mathematical Instruments and the Principles and Practice of Levelling, &c., by F. W. Simms, Esq., Surveyor and Civil Engineer; Professional Papers, Royal Engineers ; Outline of the Method of conducting a Trigonometrical Survey, &c., by Captain Frome, Royal Engineers; Practical Geodesy, by Butler Williams, Esq., C.E.; French Aide-Mémoire, &c. On the subject of Military Reconnoissance I have derived much valuable assistance from Captain W. C. Mayne's ably-compiled treatise from the works of foreign officers. The Plan and Report on Malaga, and Route from that city to Granada, are contributed by a very able staff-officer, Major Charles Rochfort Scott.

INTRODUCTION.

FREDERICK of Prussia originated what may be termed Military Topography, or the art of depicting the face of a country on a large scale in aid of military operations; and, from his day up to the present time, every eminent Commander has paid great attention to the subject.

Most countries of Europe are now tolerably well mapped; but general maps, although indispensable in warfare, are never on a scale extended enough for every purpose. The Trigonometrical Survey of England, for instance, on a scale of an inch to a mile, is quite sufficient for combining military movements generally; but a Commander in the field requires also to have more detailed plans of the territory over which his operations are likely to carry him, for the purposes of manœuvring and disposing his forces to the greatest advantage, both for attack and defence.

A perfect knowledge of the ground is, in short, necessary for a General. To obtain this knowledge by a personal examination amid the many calls upon his time and attention, occasioned by the varied and important duties he has to perform, is manifestly impossible; and hence the necessity of having attached to the Staff of an army, certain individuals qualified to furnish plans, sketches, and reports of a country: such were in our service, during the late war, the Officers of the Royal Staff Corps.

It may be observed, that a good plan conveys to the mind a more perfect image than can be obtained by looking at the ground itself. A plan enables us to examine and compare the great features of a country: we trace on it the directions of lines of coast, of mountains, rivers, roads, forests, &c.distance is nothing: we see the country, twenty, fifty, a hundred miles off: we can estimate the comparative heights of hills without having to bear in mind that the angle subtended by a mountain varies with its distance from the eye; or that such an art as perspective exists. Nay, more, it may be asserted that a really good plan is fully equal, I had almost said superior, for military purposes, to the best model.

Further, the utility of military plans is not confined to the period of actual operations in the field, but is also felt afterwards. Without them, what would be the science of war? The profound combinations of the General, as well as the graphic descriptions of the Historian, would indeed avail us little, if the narrations of the latter were not illustrated by plans.

In conclusion: The service requires not merely that plans should be executed, but also that the General and others, for whose information they may be prepared, should understand them. Hence, every officer-for all hope to rise in rank-ought to be sufficiently acquainted with Military Surveying to understand its language as used in a plan, or- to employ an erroneous, but common mode of expressing the same thing-should have a knowledge of the principles of plan-drawing.

Certain details in a plan, as roads, rivers, houses, woods, &c., are, at a glance, comprehended by