3

C.—lA

Field Inspections. Sixty-five field inspections have been made during the year by senior staff surveyors, and the work disclosed has, with two exceptions, been up to regulation standard. It is anticipated that more of these inspections will be made during the coming year, especially in those districts which have not had sufficient made during the year under review. Tidal Survey. The operations for the year under report comprised the analysis of the tidal observations at the Port of Dunedin for 1927, together with two complete analyses of the observations at the Port of Lyttelton for 1926 and 1927. The constants derived therefrom, combined with previous determined values, are contained in Table C.

Table C. Mean Values of the Harmonic Constants for Use in preparing Tide-tables.

The tide-tables for the year 1930 for the seven New Zealand ports (Auckland, New Plymouth, Wellington, Lyttelton, Dunedin, Bluff, and Westport) for which tidal predictions are published were received in Wellington on the Ist August, 1928, from the Hydrographer of the Admiralty. The work of measuring the times and heights of high and low water was again performed at the Tidal Institute, University of Liverpool, England. In addition to the above, the comparisons between the predicted times and heights of high and low water for the year 1927 at the following ports —Auckland, Wellington, Lyttelton, Dunedin, Bluff, and Westport—and the actual times and heights of high and low water as recorded by self-registering tide-gauges, were completed. Details of these comparisons have been published in Volume V, Records of the Survey of New Zealand. For the Port of Greymouth mean high tide has been determined from automatic tide-gauge registrations for the years 1923 and 1924, and equals 9-87 ft. above the zero of the gauge.

Auckland. Bluff. Dunedin. Lyttelton. New Plymouth. Wellington. Westport. A 0 =6-72ft. A 0 = 5-27 ft. A o =3-30ft. A,=.3-06ft. A o =5'50ft. A„=2-93ft. A„=4-77ft. Tide Symbol. * H. | K. H. K. H. K. H. K. H. K. H. K. H. K. Short Period. Ft. 0 Ft. ° Ft. ° Ft. ° Ft. ° Ft. , Ft. 51 0-011 31-74 0-010 100-05 0-013 71-77 0-019 21-79 0-011 90-77 0-002 ! 354-03 0-011 78-04 52 0-580 268-31 0-502 49-79 0-244 126-96 0-149 142-47 1-103 306-14 0-100 330-28 0-959 332-22 S4 0-019 331-83 0-009 223-42 0-006 312-97 0-008 196-61 0-008 352-33 0-004 215-90 0-007 32-75 S6 0-003 41-77 0-006 170-17 0-003 108-45 0-013 338-20 0-006 88-73 0-004 310-31 0-006 331-21 Ml 0-009 144-71 0-011 127-33 0-008 52-73 0-009 119-85 0-008 71-92 0-006 22-11 0-012 143-08 M2 3-818 206-37 2-858 35-68 2-401 122-64 2-887 122-42 3-986 277-36 1-611 138-99 3-747 304-43 M3 0-039 199-21 0-011 272-74 0-012 264-53 0-013 170-18 0-030 151-30 0-019 175-72 0-021 208-15 M4 0-106 124-54 0-088 226-45 0-263 180-66 0-009 126-78 0-078 52-77 0-04] 251-1] 0-057 53-90 M6 0-026 314-33 0-086 79-53 0-061 1-85 0-022 62-85 0-023 262-35 0-012 98-61 0-026 36-82 01 0-053 145-25 0-113 72-91 0-085 68-53 0-085 59-60 0-046 103-23 0-103 36-57 0-C93 45-98 K1 0-235 169-17 0-058 115-68 0-077 94-21 0-151 58-08 0-205 186-06 0-082 84-49 0-073 184-39 K2 0-139 256-95 0-134 46-77 0-083 110-95 0-049 .108-29 0-309 297-39 0-044 7-49 0-276 328-04 PI 0-077 163-91 0-023 105-44 0-023 93-39 0-048 89-55 0-063 179-23 0-032 77-13 0-022 133-91 J1 0-017 185-22 0-006 198-96 0-009 103-80 0-009 140-62 0-018 222-36 0-010 178-05 0-013 219-25 Q1 0-009 67-58 0-031 47-70 0-028 67-40 0-022 62-32 0-019 38-27 0-036 22-17 0-037 33-03 h2 0-108 219-79 0-109 32-44 0-185 120-62 0-083 169-54 0-122 278-28 0-029 156-82 0-097 285-41 N2 0-793 179-27 0-654 16-50 0-530 102-48 0-655 90-84 0-821 261-11 0-398 104-65 0-770 289-02 y2 0-203 206-34 0-153 53-35 0-125 100-67 0-155 93-39 0-177 264-28 0-107 113-02 0-194 320-40 0-102 178-49 0-065 7-93 0-035 56-62 0-116 65 27 0-127 242-24 0-067 88-08 0-134 283-83 T2 0-057 294-82 0-020 89-11 0-018 269-28 0-026 237-96 0-078 316-01 0-031 280-97 0-053 9-08 (MS)4 0-173 195-31 0-081 2-78 0-104 141-94 0-107 110-38 0-095 258-14 0-035 133-28 0-105 294-78 (2SM)2 0-066 303-10 0-045 121-63 0-038 14-29 0-058 27-03 0-088 222-36 0-033 356-74 0-076 199-89 R2 0-015 211-16 0-014 111-90 0-029 185-73 0-017 167-18 0-032 300-05 0-011 138-68 0-035 178-80 Long Period. Mm 0-045 195-02 0-043 1-94 0-052 329-47 0-067 191-13 0-060 337-01 0-039 174-85 0-051 199-18 Mf 0-050 206-01 0-067 235-36 0-085 256-46 0-069 221-75 0-026 365-26 0-060 232-19 0-055 7-87 MSf 0-035 209-57 0-063 326-77 0-058 151-61 0-055 191-04 0-081 190-54 0-043 106-30 0-069 98-39 Sa 0-186 30-61 0-089 16-98 0-127 268-75 0-171 3-81 0-077 86-54 0 108 332-12 0-113 81-51 Ssa 0-071 164-94 0-115 82-05 0-094 231-27 0-069 240-81 0-084 43-84 0-073 111-04 0-116 111-03