C.-lA

4

published were received in Wellington on the 3rd August, 1926, 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, England. Magnetic Observatoby. During the year the Eschenhagen magnetographs at Amberley and the Adie magnetographs at Christchurch have been kept in operation. The mean values for the year 1926 of the magnetic elements obtained from the hourly measurements of the magnetograms are as follows : — Mean Value, Change since 1926. 1925. Magnetic declination (east) .. .. .. .. 17° 26-0' + 4-87' Magnetic horizontal force .. .. .. .. 022141 C.G.S. —25y Magnetic inclination (south) .. .. .. .. 68° 15-6' -j- 1-4' Northerly component .. .. .. .. 0-21124 C.G.S, —34y Easterly component. . .. .. .. .. 0-06633 ~ +23y Vertical component .. .. .. .. .. 0-55525 ~ +3y Total magnetic force .. .. .. .. 0-59777 „ —34y The customary diagrams showing diurnal variations have been drawn for publication in the "Records of the Survey of New Zealand" and the coefficients of the first four terms in Fourier series have been computed for the seasonal and annual diurnal variations. Milne seismograph No. .16 has been kept in operation, and the resulting seismograms measured for publication. The customary daily meteorological observations have been made. In addition many observations of wind directions and velocities in the upper air have been made with apparatus lent by the New Zealand Institute. Mr. Baird, assistant, was on loan with the apparatus to the Scientific and Industrial Research Department during February for the purpose of making such observations at the Wigram Aerodrome, Sockburn, and it is expected shortly to publish records up to date of nearly one hundred balloon flights, since the Secretary of the Scientific and Industrial Research Department has kindly offered to allow the Sockburn observations to be included with the Christchurch series. This is contingent on the permission of the New Zealand Institute being obtained. Mr. H. F. Baird and Mr. P. W. Glover have co-operated in the work, and beyond ordinary hours much labour has been expended upon this research. Hourly values of magnetic elements for 1926 and 1906 are prepared for publication in the forthcoming volume IV of " Records of the Survey of New Zealand The mean annual values of the magnetic elements, as far as they are available, are shown in Table D following.

Table D. Mean Annual Values of the Magnetic Elements at Christchurch Observatory.

, Declination Annual Horizontal Annual Vertical Annual Inclination Annual , 'IT, k! i' Date. E. ofN. j Change. Force. Change. Force. Change. South. Change. ' Annualltcports O ' ' C.G.S. Unit, y C.G.S. Unit. y or , 1902 .. 16 15-1 ... 9 0-22694 0-55277 , Q 67 40-80 , , ... 1912-13 1903 .. 16 18-3 in 0-22669 _ 9 ° 0-55286 J_9l 67 42-30 I|°" 1912-13 1904 .. 16 21-8 0-22644 0-55307 67 44-10 + 1912-13 1905 .. 16 25-4 l9 , 0-22628 0-55348 67 45-80 ,, an 1919-20 1906 .. .. + 2 ' 4 .. " 23 •• +2H .. +18 ° 1907 .. 16 31-1 " -• •• " .. 1908 .... 1909 1910 .. 16 37-6 + y. 4 0-22515 0-55485 _^j 2 67 54-80 1920-21 1911 .. 16 39-0 +2 . g 0-22494 _ ;J3 0-55497 67 56-20 +1-0(( 1913 !! 16 44-0 "g 0-22449 _\ j5 0-55478 ;j. ( 67 58-20 |_j^ 0 1913-14 1914 .. 16 44-8 , 9 , 0-22414 0-55465 , - 67 59-80 . „„ 1914-15 1915 .. 16 47-0 I,a 0-22387 _t' .. + .. 1 *Sept., 1918 1916 .. 16 49-8 +3! 0-22355 " .. " . *Sept„ 1918 1917 .. 16 53-0 , 97 0-22328 __ 9 , 0-55486 „ 68 04-80 *Mar., 192' 1918 .. 16 55-7 I;'' 0-22304 _f 0-55516 Z' 68 06-70 ' 1918-19 1919 .. 16 58-6 0-22280 0-55507 +1 g 68 07-80 1919-20 1920 .. 17 01-7 , 9Q 0-22261 9 „ 0-55525 , 68 09-20 f 1920-21 1921 .. 17 04-6 "I"- - ; 0-22241 0-55528 I"? 68 10-30 In on fl921-22 1922 .. 17 08-3 0-22217 0-55507 68 11-20 f 1922-23 1923 .. 17 11-7 is,, 0-22209 91 0-55526 68 12-00 , „ J Vol.' I. 1924 .. 17 16-4 IT, 0-22188 _ 9 J 0-55508 _f° 68 12-73 T"''* +VOU II. 1925 .. 17 2.1-1 J*'' 0-22166 1± 0-55522 68 14-20 I};*' J Vol III. 1926 .. 17 26-0 + y 0-22141 0-55525 1 a 68 15-60 * * Mean hourly values published in New Zealand Journal of Science and Technology. t Special publication. J Records of the Survey.