19

C—lα

APPENDIX lII.—TRIANGULATION. [By C. E. Adams, M.Sc., P.R.A.S., Chief Computer.] The office-work on the triangulation has comprised the usual routine of calculations, such as checking abstracts of horizontal angles and calculating spherical excess in preparation for noncircuit adjustments; preparing and draughting diagrams; adjusting polygons and triangles to consistent geometrical figures by least squares; calculations of latitudes, longitudes, and azimuths from co-ordinates; calculations of tables of PB 2 E tan <j> and of cot ft + 3tan ft „* to facilitate 6 <f>" these calculations; checking table of natural tangents to nine figures tor use in geodetical calculations. Mr. E. J. Williams has carried out these calculations in a satisfactory manner. Electric Measurement of Temperature of Steel and Invar Measuring-bands. —Further work has been completed at this research, and I have to acknowledge the valuable assistance of Mr. W. Stuart, M.Sc, and Mr. G. B. Dall, who have made extensive series of observations, and have now sufficient information to show that a simple practical and convenient outfit can be made for easy use in the field. Kaingaroa Base.—Length., 91198-830 links = IT4 miles; probable error, ± -0147 or 1 in 6,217,000; date measured, January, 1912, February, March, and April, 1913; total number of days, 43 = 3'B days per mile. Auxiliary base: Length, 12149-035 links =15 miles; probable error ± '0032, or 1 in 3,785,000; date measured, March, 1913; total number of days, 6 = 4-0 days per mile.

APPENDIX IV.— TIDAL SURVEY. [By C. E. Adams, M.Sc, Jb\.R.A.S., Government Astronomer of New Zealand.] Haemonic Analysis. The harmonic tidal constants for Dunedin have been obtained from an harmonic analysis of the hourly ordinates of the automatic tide-gauge records at Dunedin. Darwin's tidal abacus was used, and the whole of the measurements and calculations have been carried out in duplicate and with independent checks where necessary. The constants have been checked by computing from them the heights of the tide on different days and comparing the values with the gauge records. The results have shown that the constants have been determined correctly.

Harmonic Tidal Constants from Hourly Ordinates,

>une< in, cw if; i an' . Longitude, 170° 30' east of Greenwich; latitude, 46° 7' south, of observation, one year, beginning 1911, July 1. Period Tide. R in English Feet. f in Degrees. H in English Feet. k in Degrees. s, s 2 s 4 s 6 M, M 2 M 3 M 4 M. K 2 P J Q T 0-016 0-251 0-006 0-005 0-005 2-453 0-012 0-239 0-075 0-102 0-069 0-110 0-030 0-005 0-033 0-153 0-523 0-042 0-016 0-008 0-027 0-109 0-025 0-064 0-103 0-102 0-099 0-046 294-24 125-38 318-00 60-60 217-58 233-81 85-44 38-68 335-67 185-74 72-84 276-09 58-92 58-35 232-88 321-14 286-62 316-69 189-72 152-22 262-25 253-04 253-36 322-23 231-30 344-80 100-42 212-03 0-016 0-251 0-006 0-005 0-004 2-535 0-019 0-255 0-082 0-088 0-062 0-086 0-030 0-004 0-029 0-116 0-540 0-043 0-017 0-008 0-027 0-113 0-026 0-072 0-073 0-106 0-099 0-046 294-24 125-38 318-00 60-60 177-98 121-48 276-94 174-01 355-52 302-12 90-01 130-04 34-20 128-89 279-75 102-80 104-75 166-56 329-09 159-52 66-95 140-70 357-73 39-56 181-16 105-36 213-18 77-44 V MS 2SM Mm Mf MSf Sa Ssa