D.—No. tt

The Board appointed on the Bth July, 1869, "to report upon the Longitude of Wellington, and of other parts of the Colony in relation to the Initial Longitude of Wellington," have the honor to communicate the result of their inquiries, for the information of His Excellency the Governor. The longitude of Pipilca Point, in the Harbour of Wellington, was originally fixed at the separate visits of Her Majesty's survey ships "Pandora" and "Acheron," in 1852 and 1854 (by the chronometric measurement of the meridian distance from Sydney), every precaution being taken to secure a correct initial meridian as the basis of the elaborate coast survey of these Islands, which has since been so admirably executed under the direction of the Admiralty. Tho longitude thus determined for Pipitea Point was llh. 39m. lTs3sec. 8., or 174° 47' 5,3" E. At an early date after their appointment, the Board communicated with Mr. Ellery, the Government Astronomer in charge of the Melbourne Observatory, and received from him the valuable memorandum appended to this Eeport. Mr. Ellery recommended that until the Board had command of sufficiently accurate appliances, it would be better to rely on chronometric measurement of the meridian distance from the Melbourne Observatory, the longitude of which has been now established, and to confine the astronomical observations to the accurate determination of local time. The Board, desiring to act in accordance with this advice, obtained the assistance of the navigating officers of H.M.S. " Challenger," who compared, with chronometers on which they placed full reliance, the Timeball time of Sydney with that of Wellington. The results thus obtained agreed within "27 of a second with those of H.M.S. "Acheron" and " Pandora." The Board recommend, therefore, that the official longitude of the chart shall bo, for the present, presumed to be correct, and adopted as the initial longitude of New Zealand, from wliich all other longitudes shall be determined. By this course all ground for questioning the longitude will be removed, and the Board feel assured that the limit of error w^ould be less than a mariner is capable of determining with the instruments at his command on shipboard. The Board do not wish to convey the impression that the official longitude thus created should not be subject to further verification and amendment, but they are clearly of opinion that it is not desirable to keep it an open question for the sake of any small possible error, nor to delay longer the far more important work of ascertaining the differences of longitude between different parts of the coast line of these Islands. These differences can be accurately determined by telegraph, and laid down in their correct relation to the meridian of Wellington; and if any further change requires to be made in that longitude, only the meridian lines on the charts will require alteration. The extension of the telegraph to most parts of the Colony makes the determination of the meridian difference between its different parts easy of attainment. The usual course is to observe the local time by transits at the two stations, and to compare the time at each place. The objection to this course is the irregularity of instruments and of the personal error of observers; and the Board therefore recommend a modification of this plan to be adopted, as more likely to give reliable results. This is, that by telegraphic communication with the Observatory tho difference in time of the actual transits of the same stars over the meridian of the two stations should be observed on the same clock. By a few preliminary observations of high and low stars, the two instruments can be readily adjusted in the meridian, and very few observations will suffice to establish the meridian difference required. With the view of carrying out this determination, which, as the foundation of all accurate surveys, is one of the most important works that can be undertaken in the Colony, the Board strongly urge that one of the "Sectors" recommended by Mr. Ellery for this purpose, and also for the determination of latitudes, should be obtained, and placed ill the hands of a competent observer. James Hectob, Colonial Museum, 10th August, 1870. Chairman.

Gentlemen, — Melbourne Observatory, 15th September, 1869. I have been instructed by trie bead of my Department, to furnish whatever information in my power to give, that may be required by the Board of Longitude of Wellington, and I have now the honour to assure you of the gratification it will afford me to be of any service to the Board in obtaining the objects they have in view. I had several conferences with Mr. G. A. Woods, during his late visit to Victoria, relative to the determination of the geographical position of Wellington, and I believe I am fully informed of the requirements of the Board, and of the appliances they have at command. I was requested by Mr. Woods to place in writing the various suggestions I made to him concerning the several points on which he questioned me, and I do so with much pleasure. Ist. With regard to the determination of the longitude of Wellington, I suggested the method I

REPORT UPON THE LONGITUDE OF WELLINGTON, AND OF OTHER PARTS OF THE COLONY IN RELATION TO THE INITIAL LONGITUDE OF WELLINGTON.