NOTE 1. In the last example every field is measured separately; but they are so connected by the chain-lines that no difficulty can arise to the learner in planning them. It may also be observed that no proof-lines were measured; but they should never be omitted in practice: if they be, the surveyor cannot depend upon the accuracy of his work.

2. If the foregoing estate be laid down upon a sheet of drawing paper, by a scale of one chain, or of two chains to an inch, a finished plan may then be made and ornamented with Indian ink, in a similar manner to Plates IX. and XI. Or the quickwood hedges may be made by a pen and Indian ink; or they may be represented by running narrow shades of colouring along the lines which form the boundaries of the fields; and each field may then be washed over with a different colour, mixed up thinly with water, and laid on with a small brush or camel's hair pencil. (See Part V. for the method of transferring a rough plan to a clean sheet of paper, in order to make a finished plan, with proper embellishments.)

3. In drawing the finished plan, all the out-boundaries may be considered as belonging to the fields which they respectively adjoin; that fence from в to c may be made as belonging to No. 1, that from c to D as belonging to No. 2, that from c to E as belonging to No. 3, and that from c to H as belonging to No. 4. (See a remark on the 27th page relating to fences.)

4. The title of the finished plan of the foregoing estate may run thus :-Plan of an Estate lying in the Parish of Bradford, in the West-Riding of the County of York.

PROBLEM IV.

Meres and Woods.

The method of measuring Meres and Woods by the Chain and Cross has already been shown in Part III. It is here proposed to survey them by the Chain only.

In this case, you must not only measure on the outside of the mere, or wood, and take insets as before directed; but also take such external angles, or tie-lines, as will enable you to lay down the figure.

Example.

Let the following figure represent a mere, the area of which is required :

Begin at + 1, and measure eastward as far as you proceed; then produce the line to + 3. measure northward as far as 4; thence run

3

as + 2, taking insets Return to +2, and a line backward to

Return to + 4, conReturn to +5, and which and + 6, being Return to +7, and +1, and you will

+ 3, which will tie the first and second lines. tinue the line to + 5, and produce it to + 6. proceed westward to +7, the distance between measured, will tie the second and third lines. continue the line to + 8. From + 8 proceed to have obtained the following dimensions.

NOTE. Here it may be observed that after the first three lines are laid down, the fourth line will exactly reach from + 8 to + 1, if the operations have been performed with correctness.

Answer.

Having constructed the figure, you will find the diagonal, drawn 2085, the perpendicular from + 2 upon the 950, and that from + 8 = 890 links.

from 1 to + 5

diagonal

=

Double areas

=

3836400 trapezium made by stations 1, 2, 5, and 8.

To measure and plan Roads, Rivers, Canals, &c.

In measuring roads, rivers, or canals, angles or tie-lines must be taken at the different turns, in order to lay down the chain-lines; and offsets must be taken to the boundaries, as you proceed to enable you to draw the plan.

NOTE 1. The length of a road is generally returned either in miles, furlongs, and poles, or else in miles and yards. (See the Table, page 30.)

2. A machine called a "Perambulator" is sometimes used to ascertain the lengths of roads. It has a wheel of 8 feet 3 inches, or half a pole, in circumference, which being made to pass over the ground, puts in motion the clock work within ; and the distance measured is pointed out by an index on the outside. This instrument is much more expeditious for measuring the length of a road than the chain, but it is certainly less correct; for by the wheel passing over stones, sinking into holes &c., the distance is made to appear more than it is in reality.

Examples.

1. Let the following figure represent a serpentine road, a plan of which is required.