173

circummeridional altitudes of stars north and south of zenith. The latitudes as follows:—

At Mt. Nicholas. S. of Z. N. of Z.

Mean latitude of Mt. Nicholas 45 07 48. S.

At Trig. Station A., North Taieri

1¼d. to 2¼d. per acre. This is to be accounted for partly in the rise of wages, but more in the remoteness and ruggedness of the districts.

Section survey will be seen to have cost 6¼d. to 8¼d. at first, rising subsequently to 12d. and 15¼d. per acre. The cause may be ascribed to the same facts stated above. I may note here that the contract surveys at the foundation of the settlement cost 8d. per acre; but the surveys included neither the selection of roads nor reserves, but were marked arbitrarily in rectangles over the face of the country.

The cost of town allotment survey at the outset will be seen to have been 18s. 2¼d., and latterly £3 14s. 6d. per acre. This great rise is accounted for in the remoteness of the towns to be laid off, the few sections ordered, and the great amount of travelling in proportion to service required in consequence.

I also append Return of Lithographic Office. The value of work executed being £396 13s. 3d. and expenditure £298 18s. 5d. As there is now a large store of maps constantly on sale, it is to be hoped that from year to year the returns will be more satisfactory. In noting this branch of the office, I must solicit the notice of Government to the map of the Province drawn by Mr. Sprent, and printed by Mr. M'Coll, which, in style, I have no hesitation in saying, surpasses anything of the kind in the Australian Colonies.

In regard to the office assistants, I may state that the routine work has steadily progressed under the direction of Mr. Ross, Chief Draughtsman. The accession of maps and surveys makes this branch the more and more onerous; but by strict adherence to system of record, I doubt not that the responsibilities will be met without fail.

As the Gold Fields surveys have lately been placed under this office, I may remark, that I shall give my earnest attention to placing them on a footing calculated to meet the wants of the miners and agricultural settlers. But some time will be required in organization and regulation of duty, so as to maintain the work in full efficiency.

For this coming year I would suggest that, considering the greater tendency of the isolated or spotting survey now in course of execution to error, and considering the great extent of establishment by the addition of the gold field surveys, it will be necessary that Mr M'Kerrow be employed as Inspector of Surveys, the duty being to proceed to every camp and outstation to examine instruments and equipments, and check work on the ground, and generally by personal visit to supervise the field officers, and thus guarantee that duty is properly performed. The duties otherwise of the general survey will go on as heretofore, and as I will at an early date visit the gold fields I will then advise as to any measures required in this branch.

I have the honor to be, Sir,
Your most obedient servant,
J. T. Thomson,
Chief Surveyor.

Dunedin, 13th August, 1866.

To J. T. Thomson, Esq., Chief Surveyor.

Sir—I have the honor to report on the results of astronomical observation in connection with the extension of the standard bearings during the past season, and also, generally, on the results of former seasons.

Observations for latitude, true meridian, and variation of compass, were conducted at Mount York and Mount Nicholas, and the latitude of Trig. A, North Taieri, was also re-determined. The latitude of each station is the mean result of several independent sets of circummeridional altitudes of stars north and south of zenith.

There were from ten to twenty circummeridional altitudes taken of each star. All the observations were obtained under favorable circumstances of weather, there being neither clouds nor wind worth mention on the nights of observation. At Mount York the nights were generally cloudy, so that the time of taking observations was necessarily extended over a considerable period. At Mount Nicholas and North Taieri no such cause of delay occurred, the successive nights at both stations being remarkably calm and clear.

The stars have been so selected that in each pair the one does not differ much from the other in altitude and R. ascension. In this way, any constant error, either instrumental, tabular, or personal, will affect both altitudes similarly; and from the principle of the observation, any such error is entirely eliminated in the resulting latitude.

In regard to the re-observation for latitude at Trig. A, North Taieri, it is necessary to state that several sets of observations of the stars Achernar and β Ceti were taken there for latitude in November, 1863; but as the weather was then very broken, and the sights more or less interrupted by passing patches of cloud, no great reliance was placed on that determination. It appears now, however, that any errors due to unequal refraction must have compensated each other, for the latitude then determined differs only 1.4 seconds from that just obtained. The latitude of November, 1863, being 45° 51' 50" S., and of July, 1866, 45° 51' 48.6" S. The latitude of observation point being also determined from star observation, and the distance between it and Trig. A, North Taieri, known from the minor triangulation, the means of comparing the difference of latitude between the two stations as determined by astronomical observation and by triangulation.