C—la

4

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

The tide-tables for the. year 1925 of the six New Zealand ports for which predictions are published were received in Wellington on the 6th December, 1922, from the Director, National Physical Laboratory, Teddington, where the tidal predictions have been prepared satisfactorily since 1921. The removal of the tide-predicting machine from the National Physical Laboratory to India left the Hrm of Messrs. Edward Roberts and Sons the sole source of supply of harmonic predictions within the Empire, with the exception of India, until an alternative source of supply was developed at the Tidal Institute University of Liverpool, due to funds generously provided by Sir A. A. Booth and Mr. C. Booth in the first place, with Professor Proudman as honorary director. The primary object of the Institute, is " to prosecute continuously scientific research into all aspects of knowledge of the tides " ; another object of the Institute, is to carry out research work for other bodies in connection with the analysis of tidal observations. A communication was received from the Hydrographer to the Admiralty, dated Bth December, stating that tidal predictions for the six New Zealand ports have been ordered from the, Tidal Institute! for delivery by the Ist June, 1924, at a cost of £15 per port, and that full arrangements for the permanency of the work of the Tidal Institute have been made. The work is carried out under the. direction of competent officials, and the Admiralty is represented on the governing committee. The report by Mr. B. J. Williams, Tide-computer, appended hereto, contains further details of the tidal work. Magnetic Observatory. During the year under report the work of the Magnetic, Observatory at Christchuroh and the substation at Ambcrley has been efficiently carried on by the Director, Mr. H, F. Skey, B.Sc. His report is published as an appendix hereto. The magnetographs have continued, in regular operation throughout the year, and. the, base values of the curves were' determined by absolute observations of declination, dip, and horizontal force, usually taken once a month. The results of the absolute observations have, appeared irr the monthly reports of the Director. The mean annual values of the magnetic elements as far as they are available, arc; given irr Table I) following:—

Tide Symbol. Auck A 0 =E .1:111(1. j-74ft. Bluff. A,-6-27 ft. Dunedin. Lyttelton. A„=3-23ft. A o =3-20ft. H. K. H. K. Wellington. A„=2-93ft. West A„=4 ;port. t-77ft. K. H. K. H. K. H. H. K. H. Short Period. SI S2 84 Ft. 0-01 I 0-577 j 0-017 O 11-01 207-73 329-51 Ft. 0-010 0-502 0-009 100-05 49-79 223-42 Ft. 0-015 0-245 0-007 0 0 0 Ft, ° Ft. i-015 14-41 0-035 31-91 3-245 129-50 0-179 143-04 1-007 318-52 0-009 202-78 Ft. 0-002 0-101 0-004 327-99 330-48 225-40 Ft. 0-011 0-959 0-007 a 78-04 332-22 32-75 S6 M I M2 0-003 ! 0-009 3-815 59-53 111-11 200-15 0-000 0-01 I 2-858 170-17 127-33 35-08 0-003 0-010 2-485 I) 0 2 )-003 115-92 0-015 344-95 1-010 108-52 0-010 99-40 2-485 122-3!) 2-879 125-03 0-004 0-005 1-008 307-40 23-12 139-02 0-000 0-012 3-747 331 -21 143-08 304-43 M3 M4 MO 0-036 0-101 I 0-025 ! 194-31 124-01 310-01 0-011 0-088 0-086 272-74 226-45 79-53 0-016 0-261 0-072 0 0 0 1-016 202-98 0-0I0 . 112-80 1-201 177-75 0-010 80-19 3-072 357-87 0-022 08-90 0-019 0-041 0-012 172-05 250-90 99-73 0-021 0-057 0-020 208-15 53-90 30-82 Ol Kl K2 0-051 0-235 0-140 j 140-07 108-40 250-42 0113 0-058 0-134 72-91 II5-08 40-77 0-088 0-074 0-091 1-088 72-39 0-088 01-40 3-074 90-24 0-148 82-58 )-09l 122-50 0-054 102-88 0-103 0-082 0-040 30-51 85-35 7-0!) 0-093 0-073 0-270 45-98 .184-3!) 328-04 I'l -II 0-070 0-020 0-009 102-90 180-70 75-19 0-023 0-000 0-031 105-44 198-96 47-70 0-023 0-004 0-028 0 0 0 3-023 94-08 0-051 112-04 0-004 78-80 0-007 140-30 0-028 70-02 0-021 43-38 0-032 0-009 0-037 79-01 173-01 20-09 0-022 0-013 0-037 133-91 219-25 33-03 L2 N2 V2 0-109 0-802 0-192 211-10 178-79 218-23 0-109 0-054 0-153 32-44 16-50 53-35 0-155 0-537 0-099 0 0 0 0-155 102-59 0-088 148-45 0-537 104-34 0-603 95-31 0-099 114-97 0-148 122-05 0-028 0-402 0-124 149-18 104-71 120-10 0-097 0-770 0-194 285-41 289-02 320-40 U2 T2 (MS)4 0-103 0-056 0-180 180-78 294-90 187-0O 0-005 0-020 0-081 7-93 89-11 2-78 0-029 0-017 0-108 0 0 0 0-029 46-38 0-091 59-29 0-017 231-08 0-030 219-85 0-108 140-91 0-102 123-98 0-005 0-029 0-035 80-02 274-37 134-93 0-134 0-053 0-105 283-83 9-08 294-78 (2SM)2 I! 2 0-005 0-016 300-51 2IO-00 0-045 0-014 121-63 11 I -90 0-040 0-014 0 0 0-046 8-44 0-000 25-99 0-014 198-62 0-013 150-12 0-032 0-010 355-14 110-03 0-076 0-035 199-89 178-80 Long Period. 'Mm m MSI 0-049 0-038 0-035 170-42 203-39 175-40 0-043 0-007 0-063 1-94 235-30 320-77 0-036 0-008 0-089 0 0 0 0-050 69-33 0-048 137-29 0-008 184-30 0-003 183-39 0-089 137-04 0-129 150-38 0-030 0-029 0-042 197-55 187-39 98-83 0-051 0-055 0-009 199-18 7-87 98-39 Sa Ssa 0-195 0-077 18-15 151-87 0-089 0-115 10-98 82-05 0-135 0-073 0 0 0-135 207-20 0-097 246-56 0-073 104-27 0-085 139-91 0-092 < -078 343-71 133-80 0-113 0-110 81-51 111-03