May 20.] THE NEW ZEALAND GAZETTE. 635

the different measurements of the base line. Scale, 40 chains to an inch.

11. The topographical map is to show the trigonometrical stations lettered, heights in feet (in red), barometrical heights marked “Bar.,” streams (in blue), hills shaded (in Indian ink); the Native or local names of places, streams, hills, &c.; roads in use (in firm burnt-sienna lines), tracks (dotted sienna), bush (green), suggested main lines of future roads (in firm red line). Shade the boundary of the district in colour. Scale, 40 chains to an inch.

BLOCK AND SECTION SURVEYS.

12. The surveyor is to be provided with a 5in. theodolite, steel band, 5-chain wire, Abney level, aneroid, prismatic compass, beam compass, protractor, mathematical drawing instruments, scales, and planimeter.

13. No magnetic bearings are admissible, unless under very special circumstances, in minor detail work, and this very sparingly. Flat or undulating country should be laid off in rectangular sections, but in rugged and hilly country the lay of the ridges and valleys must modify the disposal and form of these. It is desirable to have all the boundaries on the meridian and perpendicular; but when the general features of the country run obliquely to these, especially in rough districts, the boundaries must be arranged accordingly, so as to form lines which could be easily fenced. The less diversity of bearings the better for the avoidance of errors and multiplication of office work. When necessary, road lines may cross sections diagonally, and the area should be shown in gross and net also. The boundaries of the block in forest should be cut 4ft. wide, and in open country pared 2ft. wide, and no survey block shall exceed in length or breadth the distance of 250 chains (3⅜ miles) unless under special circumstances, however much less, or of whatever form they may be. In ranging long sectional lines crossing ridges, lockspits are to be cut so as to enable fencers to keep the right line. If the boundaries of the area to be sectionized exceed 3⅜ miles, it will be necessary to divide it into two or more survey blocks, which separate blocks can be reduced into one plan for exhibition to the public.

14. In traversing, the surveyor is to proceed to the nearest trigonometrical station and base his work on it, setting the zero of the theodolite to true meridian by means of the given bearing to an adjacent trigonometrical station. He is then to unclamp the upper plate and turn it from left to right until the signal of the forward station is bisected, or nearly so, taking care not to overshoot the point; then clamp, complete the bisection, and record reading of vernier in field-book. Then unclamp, and keep turning upper plate in same direction, or towards the right, until the back station is again bisected. A reference to the vernier will show whether the lower plate has remained unmoved. If so, proceed to the next station, and so forth, until a close with another trigonometrical station. Observe angles of elevation and depression, and reduce to horizontal value. After being located and graded, the road lines should be thus traversed, the surveyor when on a trigonometrical station having taken careful readings to many of the traverse or subsidiary points, so as to check his position as he proceeds; then boundaries of sections, if necessary, to be measured, in the second place. Offsets to irregular boundaries, rivers, or streams must not exceed 4 chains in length, and must be taken at intervals in the traverse not greater than 3 chains, but they must be taken at closer distances if necessary to correctly define the irregularities to be mapped.

15. In the evenings the surveyor should reduce his traverses on the meridian and perpendicular of a central trigonometrical station, so that no daily actual measurements get in advance of this mode of check to his operations. In rural and suburban surveys all actually chained lines (excepting to range pegs), all corners of blocks and of isolated sections, whether chained or not, and the intersections with the traverses of all boundary lines of sections, are to be calculated. Should two traverses—say, of a road and of a river—run nearly parallel and not more than about 10 chains distant, it will not be necessary to calculate both. Enter reductions into the form given in Regulation No. 104, to be forwarded with the map.

16. Unless where otherwise specially ordered, main-road lines should be pegged generally to a breadth of 1 chain, occupation or by-roads to ½ chain, main roads 3 to 4 miles apart, by-roads ¾ to 1½ miles apart, and all necessary through-roads to give access to back or adjoining country 1 chain wide. In level country the opposite angles should be pegged by setting off half the included angle and calculated distance; but in hilly and mountainous districts, where the land is of little value, the roads tortuous, and the traverses short and intricate, this may be dispensed with and the roads shown curved. At the boundary of a section or block, however, pegs must be placed on both sides of the road. Main roads should not have a steeper grade than 1 in 15; district roads, 1 in 10; and where these grades cannot be readily obtained, the case should be reported for advice: and in all cases roads should be graded on the best lines to be found, and the gradient written on the plan.

17. Having designed and laid off the skeleton of the work by survey and calculation of road traverses, the exterior boundaries of the block are to be laid out in a similar manner, and at this time all adjacent and included prior claims and their boundaries are to be investigated, for which object copies of the original plans will be furnished from the chief district offices. These claims are to be surveyed as held by established or indicated marks on the ground, showing the same by firm lines if the boundaries disagree with your own measurements based on original plans. Boundaries as by descriptions in original plans will be marked by dotted lines. If owners of prior claims cannot be found, and if all the marks of their claims are obliterated, then it will be competent for the surveyor to re-establish the boundaries by his own actual survey, recording them in firm lines. A general rule is not to interfere with original boundaries, and, with respect to the survey of land already disposed of, it is, that land sold and not granted should have the exact area marked off: land granted, but which had not previously been surveyed, or of which the survey marks are lost, should have the distances according to the grant, in preference to any attempt to lay out upon the ground the exact area granted.

18. All pegs should be sawn or dressed heart of totara, kowhai (goay), blue-gum, kauri, matai (black-pine), puriri, or hinau, 3in. by 2in., and 2ft. long, put 18in. into the ground, the hole having first been driven by an iron jumper. The front pegs of sections must have the numbers of the sections and the letter R branded on them; in bush back pegs to be branded with the numbers as well; road traverse pegs will have the letter R and the broad-arrow, ranging pegs the broad-arrow only. In forest country, at convenient distances, trees on the traverse lines should be blazed, having the linkage marked on the face. Conspicuous trees should also be branded, and their distances and bearings from section corners noted in field-book. Sections must be pegged front and back as well as at every corner, and have ranging pegs placed 3 chains distant from the front ones, with the lines pared 2ft. wide, or cut 4ft. wide up to them: should the 3-chain distance come in an impracticable place, then the peg is to be placed wherever convenient beyond, and the distance from the frontage peg given on the map. Pegs must be inserted and lockspits made at the intersection of every road, large stream, or path likely to be seen by the public. In forest where the timber has not been burned off, iron pins 6in. long 1in. square should be inserted alongside every boundary peg.

19. All pegs in open country should have trenches dug in the following manner: 6ft. long, 9in. wide, and 9in. deep. At adjacent section frontages, thus: ——[ ]——

At traverse boundaries thus: [ ]——

At corners of isolated (spotting) sections thus: [ ]——

in all cases commencing 2ft. from the peg.

20. The positions of the section pegs in the traverse lines already surveyed are to be measured on the ground and noted in the map, and should the section peg be off the traverse line the point of intersection should be given as well as the distance of the section peg from that point. The calculated distances should, where the roads are pegged on both sides, be given from adjacent pegs on same side also.

21. All crossings of creeks and tracks in public use are to be noted; also such notes are to be made as will give a sketch of the topographical features to be delineated on the working plan.

22. In mapping, meridian and perpendicular lines are to be drawn through the initial station of the survey, which initial station must be a trigonometrical station; from these, blue faint lines may be drawn so as to describe squares 5in. apart; then set off all the skeleton boundaries and traverses by scale and parallel ruler from the distances in the calculated traverse table. Ordnance protractor may be used in detail plotting.

23. Having drawn road lines and boundaries on the map, disposition of sections is to be designed, adhering as much as possible to the cardinal points for sake of simplicity and the avoidance of error. Sections should, as nearly as practicable, have a depth equal to twice the width or frontage to a road, stream, lake, or coast.

24. Measured lines are to be drawn in pink, calculated lines in black, with figures in pink and black respectively. Observed bearings are to be written in blue, and calculated bearings in black. New pegs should be marked by a small pink circle, old pegs by a small black circle. Water is to be coloured Prussian blue, roads burnt sienna, bush green. Hills to be shaded in light Indian ink.

25. A black marginal line is to be drawn round the map,