10. When a river runs through the estate, it will be necessary to continue some of your lines across the river, in order to tie the whole survey together.

11. Rivers, large brooks, public roads, and common sewers, should not be included in the area, but only delineated upon the plan. If, however, their areas be required, they should be given separately.

12. Marshes, bogs, heaths, rocks, &c. belonging to the estate, should be distinctly represented upon the plan; and their measurements separately returned.

13. You will generally have an opportunity of representing some part of each hedge in your field-book; and you may denote on which side of the ditch the fence stands, by drawing a small bush, or by specifying it in writing.

14. In surveying estates, the crossings of fences must be taken at the outer extremities of the ditches, and not at the roots of the quickwood; because the ditch, and not the fence, is the division line between adjoining fields; but in measuring enclosures which are separated by walls, the case is generally different, as the walls most commonly form the lines of division. It may also be observed, that the ground upon which a wall stands must be measured with the field to which the fence belongs, and as walls are generally broader at the bottom than at the top, it is necessary to attend to this circumstance in taking the dimensions.

15. When the Surveyor finds it convenient, he may put down stations at the outer extremities of the ditches; and in planning, these stations will, of course, fall upon the black lines, because they always represent the boundaries between adjoining fields. This accounts for several of the stations appearing on the black lines, of the rough plans, in Plate VIII. X. and XII.

16. In taking a survey, you must enter in your field-book the name of each field, or of its proprietor or occupier; or you may make such remarks, as will enable you to distinguish the fields from each other, &c., and after the plan is drawn, acquire, from persons acquainted with the estate, every necessary additional information.

17. When hedges obstruct your sight, in running the lines, it will be necessary to cut down part of their tops in order to see the poles.

18. If it should happen that you measure a line for which you have no particular use, it will serve as an additional proof: it is evident that you had better measure too many lines than too few.

19. In taking a survey, you ought to observe to whom the adjoining ground belongs; and specify the same upon the plan.

20. Some of our Practical Surveyors use only nine arrows.

When the leader has advanced ten chains, the follower goes up to him, and places his foot or offset-staff at the end of the chain, instead of the tenth arrow; but in this method I do not perceive any particular advantage.

GENERAL RULES FOR PLANNING LARGE SURVEYS.

THE method of laying down a large survey, from the field-book, may easily be acquired by practice; but as the least appearance of difficulty generally discourages a learner, it is presumed that the following directions may be found acceptable.

Having provided a sheet of drawing-paper of proper size, trace with a pencil, a meridian, or north and south line, in such a manner 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 line, which you may then take out with Indian rubber.

Next, take separately in your compasses, your second and third lines, or any two more convenient ones, forming a triangle with the main-line; and placing one foot of your compasses in the proper centres respectively, describe arcs intersecting each other. Thus will you have three points, from which to form a triangle.

In the same manner proceed with each triangle formed upon the main-line, (or upon any other line,) proving your work as you advance, until all the triangles are laid down; and if you find all your lines correctly meet, it will be an infallible proof of the accuracy of the work.

The chain-lines being thus laid down, next prick off the crossings of fences, and draw lines in their proper situations, from one crossing to another, to represent the straight fences.

The curved fences must be formed by laying down the offsets, as already directed.

When the whole survey is planned, all the fences must be drawn with Indian ink, the chain-lines and offsets dotted, and the stations, gates, stiles, &c. marked in their proper places: the sheet will then represent what is called a "Rough Plan."

NOTE 1.

When a fence represents a chain-line, it must not be dotted. 2. Practical Surveyors seldom dot their chain-lines or offsets, but only mark their stations upon the plan; but it is more satisfactory to a learner, to be able to see all his chain-lines at a single view.

3. In taking a very large survey, it is necessary that the work be laid down, and proved every night; for if an error be committed, and the survey continued two or three days before it be discovered, the detection, in the field, will probably be attended with a great deal of trouble.

4. In laying down large surveys, it sometimes happens that one sheet of paper will not contain the whole; in this case, two or more must be pasted together.

5. When you have to lay down a line exceeding the length of your scale, draw a line with your pencil, in some convenient place upon the plan; and upon it, at two or more operations, prick off the distance in question, which you may then take in

your compasses.

6. "Beam Compasses,' which are very useful in drawing large circles, taking great extents, &c., consist of a long straight beam or bar, carrying two brass cursors; one of them fixed at one end, the other sliding along the beam, with a screw to fasten it on occasionally. To the cursors may be screwed points of any kind, as of steel, pencils, &c. To the fixed cursor is sometimes applied an adjusting or micrometer screw, by which an extent may be obtained to a very great nicety." See Hutton's Mathematical Dictionary, I. 315.

DIRECTIONS FOR PLANNING THE ESTATE IN
PLATE VIII.

From the Dimensions in the engraven Field-Book.

Ir appears by the first page of the field-book, that the range of the first line is N.N. W.; and by referring to the Compass, Plate I. (page 23), we find that the angle which this line makes with the meridian line, is 22° 30'.

By Prob. 23. Part I. lay down a line making an angle of 22° 30′ with the meridian line; and by a scale of four chains to an inch, prick off 2802 links, from cross or station (+) 1, to +3; and you will thus have the part of the first line.

Now, as the third line could not be run to +1, in consequence of a large quickwood hedge intervening too far to be cut down; it was necessary to produce the first line 30 links southward, in order that the first three lines might form a triangle; consequently, the first line must be continued 30 links southward from+1, in laying down. the plan; and this continuation completes the first line.

Take the second line, 3075 links, in your compasses, and with one foot in +3, describe an arc; and with 3270 links, the third line in your compasses, and one foot in a point 30 links south of+1, describe another arc, intersecting the former in+6; join these three points by drawing lines from+3 to +6, and from+6 to the abovenamed point; and you will thus form the triangle 1, 3, 6.

Next, prick off stations 2, 4, 5, 7, and 8; and lay your plottingscale from +2 to +8, and if it measure 1046, as in the field-book, line six, you have good reason to conclude that your dimensions are thus far correctly taken and laid down.

Also, mark off+10, try its distance from + 4; likewise examine the distance from +5 to +7; and if you find both these lines the same as in the field-book, your survey is evidently correct.

With the fourth line, 257, in your compasses, and one foot in+1, describe an arc; and with the fifth line, 1004, as a radius, and+2, as a centre, make another arc cutting the former in +9; hence you have three points by which to form the triangle 1, 9, 2.

Lastly, complete the rough plan by pricking off, and drawing all the straight fences; laying down the offsets; making the gates; numbering the fields, &c. &c., as in the Plate.

DIRECTIONS FOR PLANNING THE ESTATE IN
PLATE X.

From the Dimensions in the engraven Field-Book.

WE find from the fourth page of the field-book, that the first line ranges W. b. N. 1⁄2 W., making an angle with the meridian line, 84° 221.

By Prob. 23. Part I. draw a line, making an angle of 84° 221 with the meridian line; and by a scale of four chains to an inch, prick off 5445 links, from +1 to +12; and you will thus obtain the first line; upon which prick off stations 2, 3, 4, 5, 6, 7, 8, 9, 10, and 11.

With 900, (part of the third line,) in your compasses, and+1, as a centre, describe an arc; and with 625, the fourth line, as a radius, and one foot in +2, intersect the former arc in +22. From+2, draw a line to +22; and from+1, through+22, draw the third line, equal to 1360, and you will obtain +23.

With the second line, 3790, in your compasses, and +12, as a centre, describe an arc; and with 925, part off the fifth line, as a radius, and+23, as a centre, describe another arc, cutting the former in+21. From+23, through+21, draw a line equal to 2090, and you will thus obtain the fifth line, and also stations 24, 25, and 26.

Draw a line from +12 to +21, and you will have the second line; and also stations 13, 14, 15, 16, 17, 18, 19, and 20; and draw another from + 26, to a point in the first line, 295 W. of +10; and you will obtain the sixth line; and likewise stations 27 and 28.

With 2325, the twenty-sixth line, in your compasses, and +3 as a centre, describe an arc; and with 1210, part of the twenty-seventh line, as a radius, and one foot on the first line, 150 W. of + 7, describe another arc, cutting the former in + 33. Draw a line from+ 3 to +33; and from +33, through the intersection of the first line, draw the twenty-seventh line, equal to 2040, and you will obtain +43.

Next, with 446, the seventh line, in your compasses, and +12, as a centre, describe an arc; and with 2528, the eighth line, as a radius, and 33, as a centre, describe another arc, cutting the former in+29. Draw lines from +12 to +29, and from +29 to +33, and you will obtain stations 30, 31, and 32; and also draw the ninth line from+32, through+8, and +16, to +27, and you will have stations 34, 35, 36, and 37.

Join stations 11 and 13, and you will obtain the 10th line; 28 and 30, and you will have the 11th line; 37 and 18, and you will obtain the 12th line; 19 and 25, and you will have the 13th line; 38 and 20, and you will obtain the 14th line; 20 and 39, and you will have the 15th line; 24 and 39, and you will obtain the 16th line; 39 and 19, and you will have the 17th line; 17 and 27, and you will obtain the 18th line.

From+31, through+9, draw the 20th line, equal to 1175, and you will obtain stations 40 and 41; join 36 and 40, and you will have the 19th line; and from+41, through + 34, draw a line to a point in the 1st line, 72 E. of +7, and you will obtain the 21st line.

Draw a line from +35 to +43, and you will have+42, and the 23rd line; and join +42 and 36, and you will obtain the 22nd line. Draw a line from +23 to the first line, 115 E. of +5, and you will obtain +45, and the 29th line; from +43 to +45, and you will have+44, and the 24th line; from+3 to +45, and you will obtain the 25th line.

Lastly, complete the rough plan, by pricking off, and drawing all the straight fences; laying down the offsets; making the gates; forming the bases of buildings; shading the river; numbering the fields; &c. &c. as in the Plate.

NOTE 1.-Hot-pressed drawing-paper is best for plans, because its surface is very smooth; consequently, fine lines may be drawn upon it. Parchment and vellum are more durable than paper; hence they are generally used for planning estates belonging to gentlemen who are desirous that the plans may be handed down to their posterity. Vellum exceeds parchment in durability; and it may be necessary to remark, that when either of them is used for planning, it must first be rubbed with clean flannel dipped in the best Paris whiting. This operation clears its surface from grease; and facilitates the movements of the pen.

2. In damp weather, paper expands, and in dry weather, it contracts; consequently, if a plan be drawn when the paper is in a moist state, and the content be not found till after it has become perfectly dry, the diagonals and perpendiculars will measure too little, and will of course give the area too little also; but if the plan be drawn when the paper is dry, and the area be found after it has expanded by a change in the atmosphere, the diagonals and perpendiculars will measure too much, and will consequently give the area too much likewise. Hence the necessity of having the paper in the same state of temperature when you find the area, that it was in when you laid down the chain-lines, offsets, &c.