AIDS TO NAVIGATION.

Otago Witness, Issue 2915, 26 January 1910, Page 12

AIDS TO NAVIGATION.

COMPILATION OF TIDE-TABLES. WELLINTGON, January 10. The Survey Department, irj conjunction with the Marine Department, is taking up the work of the harmonic analysis of the tides of New Zealand and the predicting j of tides for the tide-tables for the latter department. The Government has been j invited by Lord Crewe, Secretary of State i for the Colonies, to supply these particulars for insertion in the British Admiralty ! Manuals for the use of the navy and mercantile marine. It is hoped that the results from New Zealand, Australia, and oth#r parts of the Pacific will lead to the thorough investigation of the tides of the Pacific Ocean, of which the available information is at present very, meagre. The work is of a highly technical and onerous nature, involving a? it does elaborate mathematical and extensive astronomical knowledge. The latest scientific apparatus for this purpose is being obtained from England by the Marine Department to facilitate the mathematical reductions. Lord Crewe in his minute pointed out that hitherto this information had to be obtained locally wherever the captain of a vessel might be located, and therefore they wanted to issue it in future under one cover in a comprehensive form relating to all the ports of the British Empire. A start will be made with the work in the four chief centres, and it will be extended to the other ports from time to time. Strange as it may seem, the New Zealand tide-tables, in the New Zealand Nautical Almanac have been supplied bv the Superintendent of the United States Coastal and Geodetic Survey, because there were no facilities here for working out the local tides, the matter being so technical as to require special knowledge. This work has been in the pa.st very carefully done for Wellington and Auckland, and mariners are indebted to the United States Survey for its valuable assistance in the matter. It is. however, now felt that the work ehould be done bv the Domlinion's own, experts, especially as they possess the local ' knowledge of meteorological conditions. This branch of the Survey Department's operations has been placed in charge of Mr C. E. Adams, of the head office, who has made a close study of the subject.