lines. The entry of the measurements should be commenced at the bottom of the line or column, to which column the pickets should be entered as marked on the ground, to the right, left, forward, or backward, as the case may be. An inspection of the annexed copy of field-book for primary reference lines (fig. 5) will suffice in this place.

The field-book should indicate the order and manner in which the measurements are made, and be, in fact, a complete sketch-plan, with measurements, of the district surveyed. Each page of the field-book should represent a section or part of the district, and show the original entries on it between two faint parallel lines, as shown in the illustrations (figs. 5, 6, and 7). The entries copied from another page for the purpose of making connections and other reference should be shown on a single faint line. The lengths of the reference lines, and the pages on which the original entries are made, should be written, for the purpose of reference, on the copied line.

The entries for the measurements on a reference line, whether for reference or detail, should be placed on the field-book, as already stated, between the faint parallel lines. The entries for the lengths of perpendiculars from the reference line to the detail should be entered to their respective reference points, right or left, as the case may be. The space between the faint parallel lines must be regarded as of no absolute width. The measurements for the detail, except where distinctly shown otherwise, should be made on perpendiculars to the reference line. The unbroken deep lines on the fieldbook illustrations referred to shows the defined detail. The undefined detail should be shown by dotted lines.