Surveyor or his European Assistants, and are properly intersected and laid down by triangulation, in connection with the angular work of the main circuit. This duty should, on no account, be entrusted to any Native Assistants who are only qualified to follow a simple routine course, which has been duly prepared and marked out for them, and who perform mechanical duties very well, without understanding the reasons. Unless the Surveyor himself is careful to superintend, personally, this the most difficult part of his operations, the faithfulness and style of his general maps will be inevitably damaged. The operation of sketching the features of ground, cannot be rendered intelligible by description alone, nothing but a matured judgment and experience on the part of a Surveyor, will enable him to attain to any degree of accuracy in this respect. We defer all remarks on the shading and delineation of hills for another chapter. CHAPTER XIV. ON ROUTE SURVEYING AND MILITARY RECONNOISSANCE, ROUTE Surveys, although they do not come under the head of scientific or accurate works, can, however, be made to approximate so near the truth, as to become very useful in filling in the topography of countries that have not come under more detailed operations. Military Reconnoissance may be said to form a part of Route Surveying, for the latter, in a military point of view, would be of little use without the former, and a sketch of the country combined with an explanatory statistical report, constitutes what is called a Military Reconnoissance, and in which the importance of the sketch, or the report predominates according to circumstances. This duty is generally performed in India by the Quarter Master General's Department, but opportunities are numerously afforded to many other Officers in this country of obtaining information of various kinds, which might be eventually useful to the Government, in one way or other. "The object for which any reconnoissance is undertaken, naturally suggests the points to which the attention of the Officer should be principally directed; if, for example, it is merely to determine the best line of march for troops through a friendly or undisputed country, the state of the communications, the facilities of transport, and possibility of provisioning a stated number of men upon the route, are the first objects for his consideration. If the ground in question is to be occupied either permanently, or for temporary purposes, or if it is likely to become the seat of war, his attention must be directed to its military features; and a sketch of the ground, with explanatory references, together with a full and correct report of all the intelligence he can collect from observation, or from such of the inhabitants as are most likely to be well acquainted with the localities, and most worthy of credence, will demand the exertion of all his energies; upon the correct information furnished by this reconnoissance, may depend, in a great measure, the fate of the army.' Despatch and simplicity of execution are the great things to be aimed at in a military sketch, and although the greatest possible accuracy may not be absolutely necessary, yet every precaution should be taken as far as circumstances will admit. Its objects being so different from the more operose surveying, the shortest, easiest and most certain methods of practice will ever be entitled to the greatest attention. : The principles of military sketching cannot differ essentially from those of Surveying; they both consist in determining the sides and angles of real or imaginary figures upon the surface of the earth these can always be resolved into triangles, by means of which we lay down these figures upon paper to any required scale. But the practice differs very considerably, and it is for this reason that they are called sketches rather than surveys, because so much of them is usually done by the eye, instead of being a continued series of angles and measured lines, as in the more elaborate surveys. Many instruments have been contrived for military sketching, each of which has some advantage peculiar to itself, but the prismatic compass and pocket sextant, as described in pages 110 and 136, appear to be the best adapted for the kind of work. To these must be added a case of leather to hold the sketches, and an ivory protractor together with a pencil, and which are * Frome on Surveying. generally contained in the sketching case, to lay down the angles and the distances. One of the most essential things to be acquired, is that of judging distances with accuracy; upon this every thing depends in a hasty sketch, where instruments are sparingly used or excluded altogether, a few days' practice will enable an Officer to estimate with tolerable accuracy, the length and average quickness of his ordinary pace, as also that of his horse, as on a rapid reconnoissance he must necessarily be mounted, and the habit of guessing distances, which can afterwards be verified, will tend to correct his eye. An easy mode of judging distances is by marking on a scale or pencil, held at some fixed distance from the eye, the apparent diameter, or height, at different measured distances of any objects, the dimensions of which may be considered nearly constant, such as the average height of a man, a house of one or two stories, &c., will furnish suitable standards. "The degree of accuracy of which a military sketch is susceptible, depends upon the time that can be allowed, and the means that may be at hand. If a good map of the country can be procured, the positions of several conspicuous points can be taken from it and laid down on the required scale; or a rough base may be measured, carefully paced, or obtained from some known distance, and angles taken with a pocket sextant or other instrument from its extremities, to form a tolerably accurate species of triangulation, which may be laid down without calculation, and within this the detail can be sketched more rapidly, and with far more certainty than without such assistance. No directions that can possibly be given will render an Officer expert at this most necessary branch of his profession, as practice alone can give him an eye capable of generalizing the minute features of the ground, and catching their true military character, or the power of delineating them with ease, rapidity and correctness."* *Frome on Surveying. The adjoining Plate represents the form of a Report extracted from " Major Jackson's Course of Military Surveying"; and which should accompany all Route Surveys. This form was drawn up by Major Hector Straith, late Professor of Fortification, at the Honorable Company's Military Seminary at Addiscombe. It is the result of his own observations when serving in India, and is well suited to the purpose. The limits of this work will not admit of our pursuing this interesting subject any further, but the following memoranda, extracted from the same work, which are nearly a transcript of those issued by Sir George Murray for the guidance of the Officers of the Quarter Master General's Department, during the Peninsular War, will serve to point out the principal objects to which an Officer employed in the important duty of reconnoitring, should direct his attention. He must seek to acquire a good general knowledge of the country upon which he is to report, regarding its natural and political divisions, and principal features. He will then go into detail, dividing the subject into different heads, as:— I. The peculiar nature of each district of country, and its productions. Particularizing what parts of it are mountainous or hilly, and what are level: whether the hills are steep, broken by rocky ground, rise by gradual and easy slopes; or, if the ground is undulated only in gentle swells. Whether the connexion of the high lands is obvious and continued, or if the heights appear detached from each other. In what directions the ridges run, and which are their steepest sides. The nature and extent of their vallies, and ravines-where they originate, in what directions they run, whether difficult of access, or to be easily passed. Whether the country is barren or cultivated, and what is the kind of cultivation-whether vines, or olives, or corn; and if the latter, what kinds of corn are grown, and in what parts it is most abundant. If a country of pasturage, whether it is |