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In addition to the comparison of the tapes used on the. base-lines, further field data will be required before a systematic reduction of the observations and the computation of the co-ordinates can be undertaken by the office staff. These field observations include a more precise determination of the meridian of the initial station than that hitherto used, and tin- measurement of some of the angles to complete the triangles in the northern portion of Wellington District. The preparation of a number of auxiliary tables to facilitate the calculations was commenced at the beginning of the year, and was carried on at intervals whenever time was available, so as not to interfere with the more urgent work. It is proposed to continue this work at every opportunity until a complete set of geodetic tables applicable to the latitudes comprised within the Dominion is completed, When the field-work of the triangulation is again resumed I would urge most earnestly that the work should be executed on correct and scientific principles ; that only the most competent and highly trained assistants should be entrusted with this class of work, and that the apparatus and instruments used on the various operations connected with such an important survey should be subjected to adequate tests to ensure that they are capable of guaranteeing the requisite precision in the final results. A review of the methods used on the work already done and the accuracy attained in the past shows the absolute necessity for insisting on such a recommendation being enforced. In a pamphlet entitled " An Exposition of Processes and Results of the Survey System of Otago," by J. T. Thomson, C.E., F.R.G.S., in 1875, are given the methods for conducting the triangulation that has already been completed, in the Dominion, with the exception of a certain amount of work executed in Auckland and Wellington under the supervision of Captain T. Heale, Inspector of Survey, and Mr. H. Jackson, Chief Surveyor of Wellington Province, respectively. Again, in the Survey Report for the year 1912-13 (pages 59, 60) is given an historical review of the triangulation by Mr. J. McKenzio, Surveyor-General. Notwithstanding the claims made in the early days, and frequently repeated, in favour of the original minor triangulation of the Dominion as being sufficiently accurate to control the section surveys on which titles were issued, it is now known by every surveyor who has made traverses connecting the trig, stations that the system has failed in regard to prcciskm, and that the co-ordinate values of most of the triangulation stations of the original survey are not sufficiently accurate to check the values obtained by an ordinary traverse executed by an average 5 in. theodolite and the long band usually used by the staff surveyors. To a certain extent faulty measurements of the base-lines have accounted partly for the discrepancies in many eases. The theodolites usually used for the angular measurements were of the small 5 in. pattern, from which a high degree of accuracy could, not be expected. It is probable that if a better class of theodolite had been used and more care taken to guard against mistakes in the base-line measurements the system would have been completely successful, and would have established the three desiderata of precision, rapidity, and cheapness claimed for it. The Survey Report for 1914-15 contains an article in which the capabilities of the various instruments are discussed, and the limit of errors in surveying defined by mathematical demonstrations (Appendix VIII, page 66). The report by Sir David Gill in the introduction of " 'The Geodetic Survey of Southern Rhodesia," published in Vol. iii of " The Geodetic Survey of South Africa," contains much that is useful to any one entrusted with the carrying-out of a triangulation, both as regards economy in adopting a sound system of survey as well as accuracy in deciding upon the apparatus by means of which the work can be efficiently performed. With respect to the system to adopt, the following extract from a letter dated 28th January, 1897, addressed by Sir David Gill to Lord Grey, who then administered the Government, is worthy of citation : " With the universal experience of the civilized world at my back, I do not hesitate to say that it is waste and extravagance to postpone the commencement of a principal triangulation of your country. You have a comparatively clear field before you now, and the sooner you begin to base your land-tenure on a sound system of survey the sooner will you establish a system of sound title and sound evidence of title in the country, and the sooner will you stop the wasteful system of survey in proceeding from small to great instead of from great to small. . . . Every civilized country in the world has been, in the end, compelled to come to that, but not until a crop of legal troubles due to inaccurate has been laid up which takes a century to set at rest —not until four or five times the cost of systematic survey has been spent in misdirected effort." Sir David Gill, Astronomer Royal at the Cape, was entrusted with the direction of the GeodeticSurvey of South Africa.. The above extract is therefore the unbiased opinion of a. competent authority. With regard to the apparatus to employ on the triangulation, it appears that the measurement of the base-lines by Mr. J. Langmuir, Inspector of Surveys, by means of the invar steel bands, has been performed in a most careful and efficient manner, and should be satisfactory, provided that the bands were seasoned before being used on the base-line measurements, so that their lengths would remain sensibly constant in so far as the molecular stability of the metal is involved. Experience has shown a liability of these bands to shorten during a period of about two years succeeding their manufacture, after which the length can be relied upon and the bands will perform all that is claimed for them by the makers. A careful scrutiny of the field results, and an examination of the circles of the two 8 in. theodolites with which the work was commenced, show that these instruments, although excellent and well finished in every respect, are not sufficiently powerful to give the degree of precision essential in work of this class. The instrument which has given uniformly good results and which has proved satisfactory on surveys of a similar kind in other countries, as Canada, United States of America,

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