C.—la

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

The tide-tables for the year 1927 of the six New Zealand ports (Auckland, Wellington, Lyttelton, Dunedin, Bluff, and Westport) for which tidal predictions are published were received in Wellington on the 21st July, 1925, from the Hydrographer to 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. From and including the year 1928, tidal predictions for the Port of New Plymouth will be published in the " New Zealand Nautical Almanac." Complete details of the tidal work for the past year will be published in the " Records of the Survey." Magnetic Observatory. The work of the Magnetic Observatory at Christchurch and the substation at Ambcrley has been efficiently carried on during the year by the Director, Mr. H. F. Skey, B.Sc. The magnetographs have continued in regular operation throughout the year, and the base values of the curves were determined by absolute determinations of declination, dip, and horizontal force, usually taken once a month. The mean annual values of the magnetic elements, as far as they are available, are shown on Table I) on the following page.

4

Auckland. Bluff. Dunedin. Lyttelton. New Plynfouth. Wellington. Westporfc. A 0 = 5-72 ft. A c — 5-27 ft. A 0 =3-23ft. A o =3-20ft. A o =5'50ft. A 0 =2-93ft. A 0 =4-77ft. Tide Symbol. 1 1 H. K. H. K. H. K. H. K. H. K. H. K. H. K. ! I I I I . | __l I Short Period. Ft. 0 Ft. ° Ft. 0 Ft. ° Ft. 0 Ft. ° Ft. 0 51 0-011 31-74 0-010 100-05 0-014 24-76 0-031 29-19 0-012 137-44 0-002 354-03 0-011 78-0 52 0-580 268-31 0-502 49-79 0-249 128-63 0-172 142-28 1-104 305-49 0-100 330-28 0-959 332-22 S4 0-019 331-83 0-009 223-42 0-007 314-30 0-010 203-88 0-008 353-72 0-004 I 215-90 0-007 32-75 S6 0-003 41-77 0-006 170-17 0-003 109-42 0-015 342-08 0-006 73-67 0-004 310-31 0-006 331-21 Ml 0-009 144-71 0-011 127-33 0-010 75-92 0-009 72-64 0-007 99-51 0-006 22-11 0-012 143-08 M2 3-818 206-37 2-858 35-68 2-458 122-36 2-884 124-74 3-994 276-39 1-611 138-99 3-747 304-43 M3 0-039 199-21 0-011 272-74 0-015 276-65 0-013 143-67 0-030 118-32 0-019 175-72 0-021 208-15 M4 0-106 124-54 0-088 226-45 0-263 177-71 0-015 82-38 0-080 47-53 0-041 251-11 0-057 53-90 M6 0-026 314-33 0-086 79-53 0-069 358-01 0-020 64-91 0-025 258-47 0-012 98-61 0-026 36-82 01 0-053 145-25 0-113 72-91 0-091 71-60 0-087 62-94 0-043 111-59 0-103 36-57 0-093 45-98 K1 0-235 169-17 0-058 115-68 0-075 92-25 0-150 82-90 0-201 185-30 0-082 84-49 0-073 184-39 K2 0-139 256-95 0-134 46-77 0-091 116-91 0-059 106-97 0-312 296-23 ; 0-044 7-49 0-276 328-04 PI 0-077 163-91 0-023 105-44 0-023 93-59 0-052 106-11 0-058 177-60 : 0-032 77-13 0 022 133-91 J1 0-017 185-22 0-006 198-96 0-005 77-33 0-007 145-97 0-015 231-94 0-010 178-05 0-013 219-25 Q1 0-009 67-58 0-031 47-70 0-028 75-77 0-021 48-20 0-018 39-33 0-036 22-17 0-037 33-03 L2 0-108 219-79 0-109 32-44 0-144 105-44 0-084 162-36 0-132 279-04 0-029 156-82 0-097 285-41 N2 0-793 179-27 0-654 16-50 0-525 103-89 0-660 94-81 0-794 256-33 0-398 104-65 0-770 289-02 V2 0-203 206-34 0-153 53-35 0-100 101-98 0-161 109-32 0-162 313-23 0-107 113-02 0-194 320-40 U2 0-102 178-49 0-065 7-93 0-030 49-99 0-097 59-03 0-129 249-68 0-067 88-08 0-134 283-83 T2 0-057 294-82 0-020 89-11 0-018 230-31 0-026 228-18 0-075 305-18 0-031 280-97 0-053 9-08 (MS)4 0-173 195-31 0-081 2-78 0-107 140-54 0-102 120-36 0-097 260-14 0-035 133-28 0-105 294-78 (2SM)2 0-066 303-10 0-045 121-63 0-047 11-50 0-060 24-94 0-092 223-65 0-033 356-74 0-076 199-89 K2 0-015 211-16 0-014 111-90 0-022 182-51 0-017 143-74 0-029 316-98 0-011 138-68 0-035 178*80 Long Period. Mm 0-045 195-02 0-043 1-94 0-062 16-70 0-045 127-51 0-050 9-95 0-039 174-85 0-051 199-18 Mf 0-050 206-01 0-067 235-36 0-089 221-76 0-055 167-35 0-011 187-57 0-060 232-19 0-055 7-87 MSf 0-035 209-57 0-063 326-77 0-064 147-79 0-112 145-93 0-021 106-79 0-043 106-30 0-069 98-39 Sa 0-186 30-61 0-089 16-98 0-150 265-59 0-117 272-08 0-091 81-62 0-108 332-12 0-113 81-51 Ssa 0-071 164-94 0-115 82-05 0-083 119-22 0-107 143-78 0-088 136-55 0-073 111-04 0-116 111-03