cessary to run lines, in order to complete the survey; and if it happen that you put down more than are wanted, it will be immaterial. At each station you must put down a small stake, called a "station-stake," with the number of the station upon it; and also cut a mark in the ground, which may be easily done by having a small spade upon the bottom of the offset-staff. 3. In measuring your internal lines, it will give you the least trouble to run them from one station to another, if you can make it convenient; if not, you must run them from, and continue them to some chain-line, and measure the distance upon that line, to the nearest station. The place where you run upon or cross a chain-line, may be easily ascertained by setting up poles at two of the nearest stations in that line; and the crossing will be at the place where you are in a direct line with these poles. 4. The angle which the first line makes with the meridian line must be taken with a compass; and in doing this, an allowance must be made for the variation of the needle, which is about 24 degrees westerly. 5. In order to plan a large survey, provide a sheet of drawing-paper, of a proper size for use; and trace with a pencil, a meridian or north and south line, in such a position that your first station may be in some convenient point in this line. Then, from your first station, draw your first or main-line, making its proper angle with the meridian, which you may then take out with Indian rubber. Further directions appear to be unnecessary; as any person who is acquainted with the methods of laying down triangles, trapeziums, and trapezoids, will find no difficulty in planning an estate. 6. The most expeditious method of laying down crooked fences, is by means of an offset-scale, which must be used with the plotting-scale in the following manner: Lay one edge of the plotting-scale close by the base-line, and bring the end of the offset-scale in contact with the edge of the plotting-scale, so that the edges of the scales may form a right-angle; then by the edge of the offset-scale, prick off, in its proper situation, the first offset, with a pencil finely pointed. Keep the plotting-scale firm, and slide the offset-scale to the place of the next perpendicular, which prick off as before; and thus proceed until all the offsets are finished. 7. In order to find the area of an estate, practical surveyors generally straighten the crooked fences of each field, as directed in Problem II.; and then divide the fields into trapeziums and triangles, and take such dimensions, by the scale, as are necessary to find the area of each field. They then collect all the areas into one sum; afterward find the area of the whole survey, as if it were a single field; and if it be equal or nearly equal to the sum of the separate areas, previously found, they justly infer that their survey is correct. 8. Those who do not approve of finding the area by the method of casting, may make use of the offsets taken in the survey, where convenient; and if more be wanted, they may be measured by the scale; for in measuring a number of small parts by it, some will probably be taken a little too large, and others a little too small, so that, in the end, they will nearly counterbalance, each other. 9. Practical surveyors generally lay down their lines by a scale of 4 chains to an inch, when their surveys are very large; and in computing the contents, they measure the bases and diagonals by the same scale, but the perpendiculars by a scale of 2 chains to an inch; consequently, the product of the base and perpendicular of a triangle, will be its area. To treat small surveys, in a similar manner, by a scale of 2 chains and of 1 chain to an inch, must, of course, be very correct. 10. Rivers, large brooks, public roads, and common sewers, should not be included in the area, but only delineated upon the plan; and marshes, bogs, heaths, rocks, &c. should also be represented or specified, and their measurements, separately returned. 11: Sometimes the content of each field is entered within the field itself; sometimes the fields are numbered, and their areas set down, one after another, in some convenient part of the plan; and sometimes they are entered in a book of particulars. 12. When you wish to transfer a rough plan to a fresh sheet of paper, or to a skin of parchment or vellum, in order to make a finished plan, proceed thus: Take a sheet of writing-paper of the same size as the rough plan, and rub one side of it with black lead powder; then lay it upon the sheet which you intend for your new plan, with the black side downward; upon both lay the rough plan; and upon the whole place weights or books, to keep them from moving. Next, run your tracer gently over all the boundaries upon the rough plan, so that the black lead under them, may be transferred to the fresh sheet. Separate the papers and trace the lines thus transferred with a fine pen and Indian ink; as common ink ought never to be used in planning. You must then proceed to enter such names, remarks, or explanations, as may be judged necessary; drawing, by the pen, the representations of hedges, bushes, trees, woods, hills, gates, stiles, bridges, roads, the bases of buildings, &c. in their proper places; running a single dotted line for a foot-path, a double one for a carriage-road, &c. Rivers, brooks, lakes, &c. should be shaded with crooked or waved lines, bold at the edges, and fainter towards the middle. Hills may also be represented by crooked lines, bold about the middle of the hill, but fainter towards the top and bottom; and the bases of buildings must be shaded by straight, diagonal lines. Roads should be shaded with a brownish colour, laid on with a camel-hair pencil; and fields in a variety of forms, with a fine pen and Indian ink. In some convenient part of the Plan, you may write, in conspicuous characters, the title of the Estate, ornamented with a compartment. In another vacancy introduce the Scale by which the plan has been laid down; and also a meridian-line, with the compass or flower. de-luce pointing north. The whole may then be bordered with black lines at a convenient distance from each other; and the space between them shaded by a hair pencil, with Indian ink. 13. A plan well finished with Indian ink, as directed above, has a very elegant appearance, and is considered by most persons to excel those done in colours; but the work is very tedious, and requires much time to do it well, in consequence of which most surveyors prefer finishing their plans with colours. Some, however, not only embellish them with Indian ink, but also wash the different fields with various shades of colouring. 14. In colouring a plan, meadow and pasture ground should be washed with a transparent green, the pasture rather lighter than the meadow; arable land with a mixture of red and yellow, or of red, brown, and yellow, of various shades, so that too many fields may not appear exactly alike; and some surveyors use both light blue and lake, in colouring plans. An excellent green, of various shades, may be made by mixing light and blue gamboge. Rivers, brooks, lakes, &c. should be coloured with Prussian blue mixed with a little Indian ink. The hedges must be done with a strong shade, which should be softened off towards the middle with a lighter one. If the quickwood hedges be not done with a pen and Indian ink, they may be represented by running strong, narrow shades, of various colours, round the boundaries of the different fields. 15, Reeves's and Newman's water-colours are entitled to recommendation. They must be prepared for use in the following manner: Dip one end of the cake in clear water, and rub a little of it upon a clean, earthen plate; then mix it with water, by your hair pencil, until you have brought it to any consistency you please: Indian ink must be prepared for use in the same manner. 16. When parchment is used in planning, it must first be rubbed with clean flannel dipped in the best Paris whiting. This operation clears its surface from grease, and makes the pen slide more freely. 17. The learner will fully comprehend what has been said on the subject of embellishing plans, by examining a well-finished, coloured map. 18. The method of transferring plans by means of a sheet of paper rubbed with black lead, will do very well for small surveys; but when the survey is large, it is necessary, not only to transfer the original plan, but also to reduce it to a smaller scale, in order that the finished plan may be of a convenient size. This may be effected in different ways; as by squares, by proportional compasses, &c.; but the most expeditious and accurate method is by an instrument called a Pentagraph. Those who desire to make themselves acquainted with the method of using this instrument, are referred to my Land-Surveying, Second Edition; also to Adam's Geometrical and Graphical Essays, in which valuable work they will likewise find the description and use of the Plane-Table, Theodolite, Spirit-Level, and every other Mathematical Instrument. Note. The area of the following Estate, Plate III,, was found from a Plan laid down by a scale of 2 chains to an inch. The crooked fences were straight ened as directed in Problem I., and the diagonals measured by the scale used in planning; but the perpendiculars by a scale of 1 chain to an inch. The diagonals, perpendiculars, &c. are contained in the following Book of Castings. |