REPORT RELATIVE TO MEASUREMENT OF LONGITUDE BETWEEN WELLINGTON AND OTAGO BY MEANS OF ELECTRIC TELEGRAPH.

Appendix to the Journals of the House of Representatives, 1871 Session I, G-23

G.—No. 23.

REPORT RELATIVE TO MEASUREMENT OF LONGITUDE BETWEEN WELLINGTON AND OTAGO BY MEANS OF ELECTRIC TELEGRAPH.

PRESENTED TO BOTH HOUSES OF THE GENERAL ASSEMBLY, BY COMMAND OV HIS EXCELLENCY.

WELLINGTON.

1871.

G.—No. 23,

No. 1. Messrs. Jackson and Thomson to the Hon. W. Gisboeste. Sir, — "Wellington, 21st September, 1871. "We do ourselves tlie honor of forwarding, for the information of the New Zealand Government, the results of our observations for the measurement of longitude between Wellington and Otago, by means of the Electric Telegraph. As the subject of absolute or independent longitude is of jmmary importance not only to Colonial surveyors, but also to geographers and mariners, we had for some time past been occupied in determining it for our respective Provinces ; the practical object being to establish a geographical position for the initial point of the surveys conducted under our supervision. The method adopted to determine the absolute longitude in each case, was that technically termed, by " Moon Culminations/ Observations by this system were commenced in Otago en the 15th September, 1809, and the results are now given in Appendix A, herewith enclosed. The Wellington, observations were published in the New 'Zealand Gazette, No. 12, 1871. Two meridians in the Colony having been thus independently determined by different observers, it became a matter of great interest to ascertain their comparative agreement, and hence their absolute value. For this object, the kind offices of the Hon. F. Dillon Bell, then Minister of Public Works, were solicited, to obtain the sanction of Government in granting us the use of the Electric Telegraph, which were readily accorded. With the Electric Telegraph, it was in our power to compare the differences of our local limes by " Star Transits:" a method which had been largely employed, and with extraordinary success, in America, at a very early period in the history of the Electric Telegraph. Since the lowest estimate of tho velocity of ihe electric current is 16,000 miles per second, and as tho distance between the Hutt and Caversham (the sites of our respective private observatories) is about 320 miles only, the transmission of an electric signal, denoting the transit of a star across the wires of a transit telescope, from one of the observatories, is practically received by the other instantaneously. The two observatories having been placed in electric communication, the mode of proceeding may briefly be described as follows : —A list of stars was selected from the British Association Catalogue, and furnished to both observatories. Preparations having been made, the observer at the Hutt pointed the telescope of his transit instrument to one of the stars passing the meridian, and struck the signal key at the instant the star appeared to coincide with the transit wires; thus the times of the star's transits ■were simultaneously recorded from the chronometers at both observatories. As the stars selected followed in succession, by about four minutes interval, generally from two to three stars were taken at the Hutt before the first star arrived at the meridian of Kockyside, which was known to be approximately 17 m' 45 s- distant from that of the Hutt. The observer at Eockyside now pointed the telescope of his transit instrument, and the instants of the transits of the same stars were similarly recorded at both observatories. The time elapsing between the star's passage from one meridian to the other, subject to certain corrections for instrumental and chronometer errors, is the difference of longitude between the two stations. In this manner the observations were repeated as often as desired. The observatories were placed in electric communication in tho month of June, but owing to the prevalence of bad weather at this season of the year, no observations could be obtained until the Gth of July, since when, until about three weeks ago, only four nights were favourable for the operations. As a report of this nature might be deemed incomplete without a brief description of tho instruments used, and the modes practised for their adjustments, we beg to state that the instrument at Eockyside is a 24-inch transit instrument, by Troughton and Simms. It was mounted on a stone pedestal, built 3 feet into the ground, and rising 2\ feet above the floor, from which it was entirely disconnected. Over this a wooden house was erected, about 9 feet square, with the usual slot from horizon to horizon, and opening with shutters. A mean-time chronometer, by Barraud, was used. In the observations for longitude by moon culminations, the transit instrument at Kockyside was always brought to true adjustment for azimuth, level, and collimation ; but during the observations for electric difference of longitude, a different course was adopted. The azimuth of the meridian mark was again tested by eight seta of high and low and eircumpolar stars. The level of the horizontal axis was tried before and after the observations of each night, and the errors were duly allowed for in the computations. As this instrument was not provided with a micrometer, the collimation was sot true by carefully reversing upon the meridian mark, excepting on tho night of the 23rd July, when this error was determined by observing the transits of a eircumpolar star across ISTos. 1 and 2 wires; then reversing the instrument, the transits were again taken on the same wires in a reverse order. The rate of tho chronometer was tested at intervals of three to four days. The times of transits were noted from the chronometer by an assistant, at a signal from the observer.

REPORT RELATIVE TO MEASUREMENT OP LONGITUDE BETWEEN WELLINGTON AND OTAGO BY MEANS OF ELECTRIC TELEGRAPH.

G-.—N0..23.

4

REPORT RELATIVE TO MEASUREMENT OF LONGITUDE

The Hutt instrument, and the modes practised for its adjustment, have been fully described in the Report published in the New Zealand Gozette, No. 12, IS7I. The times of transits here were registered by a chronograph, consisting of an ordinary Siemens Register, but fitted with two sets of electromagnets and armature levers; one set of electro-magnets and its armature lever being in circuit with a signal key, upon which the seconds of the chronometer were beaten, and the other with the observer's key for sending signals. By an arrangement of the wires, the instant of a star's transit ■were precisely recorded by the observer, with an embossed dot upon a fillet of paper moving between the rollers of the register, and simultaneously transmitted to Rockyside. The second beats of the chronometer were similarly embossed with the other electro-magnet and armature lever upon the same fillet of paper, but upon a line separated about i-inch from the line of transit dots. The register was started and stopped for each star, taking care to note the exact beat by chronometer of the first beat on starting, and of the last beat after stopping the register. The times of a star's trausits were afterwards read off by transferring the transit dots into the line of chronometer second dots: and thus the exact second and fraction of a second, whenever the observer tapped his signal key, became precisely measured. The signals given from Rockyside were also registered by the Hutt chronometer m the above manner. The personal equation of the observers was determined at the Hutt, by one of them observing the transits of a star over the first two wires of the transit instrument, and the other, of the same star over the last two wires. The times were recorded by chronograph. Each transit was then reduced to the mean wire by the known equatorial interval between each wire and the mean wire. The difference between each observer's independent determination of the star'R transit by chronometer over the mean wire, is the personal equation. The mean of several trials furnished this equation with precision. The personal equation of the telegraphist at Rockyside, is the time elapsing between the instants of the observer giving the signal of a transit occurring, and the telegraphist transmitting the same to the Hutt. It was found, by placing two signal keys in circuit with a Morse's Register. The observer tapped one of the keys at the instant he gave the usual signal of a transit, and the telegraphist tapped upon the other key as when transmitting. The space between the two dots on the fillet of paper, when referred to the length of paper run out by the register in five to eight seconds of time by chronometer, represented, in time, how much later the telegraphist tapped his key after the usual transit signal had been given by the observer. By reference to Appendix D, herewith enclosed, it will be seen that, when the mean electric difference of longitude is applied to the Rockyside absolute longitude, the so deduced longitude of the Hutt Observatory almost identically coincides with its absolute determination. In fact, the absolute or independent difference of longitude, as observed between the two stations, agrees to within 25'fcet of the measured electric difference. That so close an agreement is a mere coincidence, cannot be doubted, as we expected to differ by about three seconds of time. But, as it is nevertheless a positive fact, brought about by two different observers, neither having a previous knowledge that the boon of being able to measure Iheir difference of longitude by the telegraph would ever have been accorded, we beg to state that the longitude of the Hutt Observatory, as derived from sixty-two moon, culminations, is ll h- 39 m-5072 s- East from Greenwich, aud that, according to probability, its error does not exceed one second of time. Since the difference of longitude between the Hutt and Wellington Observatories has been measured by triangulation, we have also been enabled to compare our result with the determinations of our predecessors on this subject. H. M. 8. Chronometric measurement by Captain Stokes, R.N., between Fort Macquarie, Sydney, and Pipitea Point ... ... ... 1 34 1553 Sydney Observatory, West of Fort Macquarie ... ... ... + 022G Difference of longitude, Sydney Observatory and Pipitea Point ... 1 34 17 79 Ditto Wellington Observatory and Pipitea Point — 288 , Ditto Wellington and Sydney Observatories ... 1 34 1491 Longitude, Wellington Observatory ... ... ... ... 11 39 1531 Ditto Sydney Observatory ... ... ... ... 10 05 0040 Ditto ditto as given in Nautical Almanack, 1871 10 04 5986 Difference ... ... ... ... ... „ 054 Captain Carkeek had for many years pursued observations for longitude by lunars, Jupiter's satellites, lunar eclipses, and moon culminations. Unfortunately his calculations have been destroyed by fire, otherwise we would have desired to incorporate his result with ours. He gives the h. m. s. Longitude of the Time Ball, Wellington ... ... ... 11 39 1700 Difference of Longitude, Time Ball and Wellington Observatory ... — 125 Longitude of Wellington Observatory ... ... ... 11 39 1575 The longitude of Otago will now be adopted from that of Wellington ; and, as the longitude of Tauranga will also be speedily determined in the same manner, by Mr. Heale, Inspector of Surveys under the Native Lands Act, there will thus be three points in New Zealand, extending nearly along its whole length, two of which will have been referred to an initial meridian at Wellington. Much being the case, and actuated by the same motives which first induced us to determine the absolute longitudes in our respective Provinces, we beg to submit for the consideration of the Government, that there shall be an initial meridian for the reference of all longitudes in New Zealand, ut Wellington; which, as its capital,

BETWEEN WELLINGTON AND OTAGO.

5

G.—No. 23.

and from its central position, is the most eligible site that could be chosen; and that this initial meridian be that of the Government Observatory, of which the longitude East from Greenwich is ll h- 39 m- 15-3P-In conclusion, we beg to record the valuable services rendered to us by Mr. Lemon and the officers of the Electric Telegraph Department. The arrangements made by them for the working of the wires were most complete, and to their cheerful assistance, we are indebted, in a great measure, for the Buccess of our operations. Our cordial thanks are also due to Mr. James McKerrow, who, at Roekyside Observatory, assisted at the observations, and calculated their results independently, by way of check. He also, night after night, in the inclement season of winter, was in attendance either at the Electric Telegraph Office, Dunedin, or the Observatory, involving a journey of six and twelve miles respectively. We have, &c, J. T. Thomson, F.E.G.S. The Hon. the Colonial Secretary, Wellington. Henbt Jackson, F.TC..G.S.

REPORT RELATIVE TO MEASUREMENT OP LONGITUDE

G-—No. 23.

6

TABLE OF OBSERVATIONS TAKEN AT THE ROCKYSIDE OBSERVATORY FOR LONGITUDE. —APPENDIX A.

o Observed Times of Transits by Solar Chron. Mean of Wires. Daily Rate of Chron. m i Longitude East. Date. Star. Wires. Weight. Remarks. 1 2 s 1869. Sept. 15 Sagittarii Moon I. Capricorni Caprieorni Moon I. Capricorni Capricorni Moon I. Capricorni Tauri Moon II. Tauri Geminorutn Moon II. Geminoruin Tauri Moon I. Tauri Geminorum Geminoruin Moon II. c.w. 30-5 05 0 395 540 130 05 0 38-5 185 280 485 335 015 515 190 535 040 09 0 28-0 205 230 18-5 440 18-5 525 08 0 260 180 525 330 42 5 01-5 470 145 035 325 OG-5 170 220 420 34-5 37-0 27-5 560 310 050 200 390 305 045 450 535 080 435 16-5 320 505 430 16-0 575 070 2G0 130 395 290 59-5 320 420 48-0 070 005 025 540 225 580 310 460 05-5 570 295 110 190 380 255 515 415 125 44-5 5G0 03 0 200 145 170 100 7 8 8 8 8 8 9 9 9 12 1 1 2 2 3 11 11 11 1-2 12 V2 !3 01 51 17 51 5s 37 51 51 10 ■22 36 55 11 03 07 10 ■11 J9 54 56-2 312 049 202 388 307 04-2 450 541 13 5 595 266 1G-2 45-8 190 298 354 542 471 498 411 12 "0 gaining 11 22 041 76 0450 Observed by J. T. Thomson. M J) JJ JJ »» „ 16 JJ )J 126 „ 15-3 79 0417 Ditto. it jj )7 H JJ „ 17 91 11 130 „ jj 09 2 8.1) 0-387 Ditto. it j) ii JJ Nov. 20 )) it 58-5 200 155 455 185 300 350 510 4G5 495 405 jj jj 000 7-7 0-439 Ditto. jj >J H ii " jj ji „ 22 u jj 11 J! 096 72 0502 Ditto. it jj 3J J> j) JJ ?J Dec. 17 jj jj It J» 00-8 7-8 0428 Ditto. tt jj 1} JJ jj JJ )) „ 19 jj jj I) J> jj jj 040 72 0502 Ditto. »J it » a it 1870. Jan. 15 if M M 0502 Ditto. j> ii jj ») „ 1G J) :> JJ t» „ 17 Orionis Moon I. Orionis Geminorum Geminorum Moon 1. Geminorum Moon II. Cancri Cancri Moon II. 83 Cancri Cancri 83 Cancri Moon 1. »i jj ii ii i) n jj 390 280 090 2G5 385 445 490 595 105 3S5 070 590 180 575 50'0 530 420 210 405 51-5 58-5 02 0 130 300 520 205 120 32 0 120 010 040 550 350 52 5 035 110 145 255 415 010 335 2J-5 440 230 1G-0 180 08 0 480 0G5 170 255 290 400 555 170 47-5 3So 570 370 300 33 0 23 0 030 205 315 405 43 5 545 100 315 025 515 110 510 445 10 10 10 11 12 11 12 V2 1 1 1 12 12 41 15 50 46 01 41 23 40 46 20 37 54 06 lo 22 05-4 55-2 352 533 04 4 120 156 265 42-7 04 6 34-2 251 44-4 241 16-9 II )J j> jj tt tt tt jj jj jj 08-8 02-5 12 7 72 70 68 0531 0563 Ditto. Ditto. J) J) ts JJ n n 18 ii ii 7) J> 085 70 0-531 Ditto. it jj JJ 11 jj Feb. 15 tj JJ )i 052 0547 Ditto. >t it jj 69 JJ JJ n JF >> i?

BETWEEN WELLINGTON AND OTAGO.

G-.—No. 23.

Tbl: — s, '.— com 'uutei

•a o Observed Times of Transits by Solar Chron. Daily Rato of Chron. & v 3 Mean of Wire?. Longitude E. Date. Star. Wires. Weight. Remarks. Ph I 1870. Mar. 17 Virginia Virginia Moon I. Moon II. 37 Virginia Moon II. 48 Virginia Moon II. 95 Virginis Moon II. Libras Sagittarii Moon II. Sagittarii Leonis Moon I. Leonis Virginis Moon I. Virginis 38 Virginis Moon I. c.w. 32 5 170 58 0 170 280 085 400 54-5 230 590 42 0 055 160 400 455 345 350 400 570 41-5 070 45-5 450 290 110 300 410 215 530 07'0 360 13-0 54-5 18-5 305 530 580 475 48-0 52 0 105 540 195 580 570 410 230 420 530 335 040 190 47-0 240 060 305 43 0 055 100 595 000 03 5 22 0 060 315 100 100 535 365 555 055 460 165 320 015 38-5 195 44 0 57-0 190 230 135 140 170 360 18-5 44-5 235 230 070 500 100 19 0 005 300 40'0 145 525 335 580 120 33 5 365 270 265 30-5 500 320 58'0 370 12 45 12 50 12 58 1 I 00 1 | 47 1 55 2 00 2 50 2 58 2 31 2 39 G 09 6 23 6 i 34 8 28 8 41 8 44 9 21 9 33 10 13 10 24 10 26 57-5 41-5 237 130 gaining 429 „ 533 131 340 047 48-4 254 127 „ 071 31-3 „ 43 7 062 10-6 12-8 004 00-7 046 „ 23 1 064 „ 321 10-8 JJ >? )J )) J? J? 11 21 58-9 59 0 590 71 7-1 7-1 0516 0516 0516 Observed by J. T. Thomson. Ditto. Ditto. „ 18 1) || N J) )i )) ."> » )> it " „ 19 >> 22 06-8 75 0463 Observed by Jas. McKerrow. )) it April 17 T) u ») 003 7-2 0502 Ditto. )» „ 21 )) j) » 17'5 71 0-516 Ditto. JJ a )> JJ May 10 )> >) 06-6 7-8 0-428 Ditto. i» n )> >> ») „ 11 *> 036 7-8 0428 Ditto. )) ii :; „ 12 )J »j jj 04-4 7-4 0475 Ditto. J) 3T 7) )* 1871. May 27 )] 0397 Observed by J. T. Thomson. )) i' „ 31 it JJ June 1 Moon I. Leonis Leonis Moon I. 94 Virginis Virginis Libra; Moon I. Libra; Moon I. Scorpii Scorpii Sagittarii Moon II. Sagittarii JJ }» )) )) JJ c!e. »j 190 140 290 11-5 220 53 5 100 375 4S'5 03 0 570 290 240 445 185 330 270 430 240 350 07-5 560 230 35 0 490 42 0 150 390 59 5 330 460 390 540 370 47 5 190 435 110 225 365 305 03 0 510 13 0 465 590 510 07 0 500 595 310 315 580 095 230 175 495 03 5 260 59o 130 010 190 03 5 13 5 450 175 43 0 56-5 075 035 360 175 42 0 145 6 02 6 05 6 37 9 16 9 21 9 28 10 01 10 10 10 17 11 07 11 11 11 18 1 10 1 15 1 24 460 159 losing 390 54-4 372 145 47-5 19-2 43-7 „ 105 224 358 156 301 02 5 510 153 130 464 j> » »i 21 22 J7 552 547 087 81 7-5 69 0463 0546 Ditto. Ditto. jj " 069 0616 Ditto. „ 2 j> :» 65 » » V J' jj „ 4 C.W. 139 61 0669 Ditto. j» J> )! " )) !' I Mean jongii ide by "Weights, 26 Observations ... 11 22 0619 1-4 12-850 J. T. Thomson, F.K.G.S.

REPORT RELATIVE TO MEASUREMENT OP LONGITUDE. I

G.—No. 23.

8

Observed Times of Transits by Sid. Chron. j True Meridian Transits. Chron. Error from the N.A. Stars. a o Apparent Riglit Ascensions from Observations Observed Times of Roekyside Transits given by Electric Signal. 1 True Meridian Diff. of Longitude. Instrumental Errors. Mean Chron. Error. a Date. Star. ■- S.5 Wires. "8 1-3 3 9, 'ransil ;s. | Wires. I 1 2 3 4 H M H M s 1 2 3 1 5 MO II M H M 1871. July 6 jj j) jj jj jj » jj jj jj jj jj jj jj jj jj jj jj a jj jj B.AC.5324 „ 5548 „ 5621 „ 5808 „ 5844 „ 5876 „ 6355 „ 6429 „ 6487 „ 6646 „ 6833 „ 6870 „ 5735 „ 5781 „ 5941 „ 5987 „ 6021 „ 6168 „ 6209 6203 „ 6487 „ 6528 „ 6168 „ 6209 „ 6371 „ 4969 „ 5227 „ 5284 „ 6107 „ 6168 „ 6263 „ 6487 „ 6528 6575 „ 6772 „ 6802 „ 6833 E. JJ )) )) }} )) ;j j) jj j» n * I s 04-4251SO 50 91 38-34 2603 13-34' 15-67,0175 05635251; 19-60'0609 28-60,12-55 1095,56-24 .34-2021-48 !46'6834-59. 45-7733-41 33-952006 0872 23-73 510303-69 4911J01-65 33-4446-79 14-1827 92 54-5907-78 33-8948-21 51-310504 3805 50-77 21-04! 33'73 41-81 5460 2093 35-30 1320 27-10 2900 4260 19 00 3383 05-84 1875 2100 35-63 39-30 52-48 3607 4994 23-32 35-94 05-97 18-58 13-70 26-93 4497 57-80 0693 1942 3650 48-95 39-2026-82 2624 1371 '00-92 48-71 48-04 34-21 B9-5226-26 52643916 57-22-40-84 41-70 26-94 08-695614 !2218100G 21-3808-31 O81552-2O 38-3lJo3-56 16-5129-27 14-23 26-80 0000 1333 42-00 56-00 120-82 3412 0223 1658 18-65 3253 1 03-65 16-47 46 52 5919, ■07-72 21-00' 4926 03-OG 1 40-7654-86' 561610-38 47-9003 10, 31-40 44-24 49-67 03-82 05-55 1910 03-10 17-00; 48-7001-20 31-1314-24 40-75 54-47 0996 22-78 32-00 44-50 01-05 13-631: 14-43 01-11 35-86 2081 \ 13 00 2571 25-68 1236 4325 5742 563S 38-07 0793 3935 2600 0099 4800 3938 52-64U 5698 41-64 08-75J 2219; 2105 oo-os! 38-45' 1649 1423 00 00 tl-98 2090 0231 18-67 03 60 46-42 07-86 49 42 40-87 56-48 48-25 3147 4962 05-71 03-39! 1862 3130 40-81 1013 3190 0120 + 038 " JJ „ )J jj )J )J » » " -005 J» JJ —6'o9 -013 JJ -dio jj + 0096 )) JJ JJ )J JJ J) JJ Jj J) JJ I I I 14 or 14 34 1444' 1511 1517 15 22 1 1636J 1649 1658 1723 1753! 1759' 1500 15 07 15 33! 15 39 15 45 1610 1617 16 24 16:58 17|O3 1610 1616 ,1641 1302 !l3'46 :1354 16,00 ;ieio 16,24 16 57 1703 1711 1744 1748 1753 3948 2620, 0122 :4805 139 51 !52-75 J57-36 4200 !09 05 22 43 ;21-29 !0618 3882 1649 14-44 i5996 112-28 2083 0216 18-56 0380: 4663 07-87 49-44 4090 5692 4821 3172 4970 05-83 0345 48-88 31-53 40-75 1033 32 09 0139 i ii jj jj ... ... 55 Ji v ■■ ... 38-99 3906| ... I 3904 3913 i ... I at ... 55 S.T.' t 3905 II. M. 19 06 + 1.75 jj Jj 'J jj ;j J) " JJ J) " L557 16 30 16 39 17,07 1713 1718 18'32 18 45 18 53 1919 1919 1954 16 56 1708 1728 1735 1741 1806 1812J 18,20 1853 1859 18-30. 05 00 4010 2695 18-41 3168 3638 2103 18 09 01-49 0039 4529 22 46 0063 58-58 44-10 !2642 ;04-97i 46-80 ,02-70 ;4791! 3077 W. 58-60 12702500 38205030 2498 „ 45-70,59-43 1215 244536-8411-71 1 „ 21-3934-5847-29 5925 1213;4693, „ 0563 19 683360 47 22 01-50|33-53; „ 5807 1191 25-34 3796I51-42 2494 „ 10412503 3855 5156 05-29J3817 „ 2857 4226 54 64 0752 2048 5469 „ 4277 5610 0852 2037 3323 08 20 ,. 4145 5506 0715 19-25 32140701 „ 22-71 37735165 0534 19655142 E. 5333 38-11 2309 0881 5349 233S „ 2770 1397 0119 1S74 3565 0145 „ 25-30 11495900 46933337 5923 „ 11-95 57-9344 843210 18-304502 -0 23141 -02314 5 -0-35150 —012152 —01615 3 -0 1415 4 -0 39171 —0-3117:4 —0-33181 -011181 + 0-10 15^ + 02915,2 + 02715 5 + 01515|5 i i 1419 14 52 15 Oi 1 1529; 1535 15|40 1715 1741 1811 1 1816 1518 15,25 15 50 1557 I I 24-75 11-48 '46-58 3311 '24-78 3803 54-30 07-89 '06-68 51-31 !23-48 0174 5950 45-17 0 JJ tt JJ J) JJ JJ JJ JJ 17 J7 •} •> V l" ... " M v ' 4529 45-30 45-38 45-38 45-29 4530 45-27 4548 45 41 4515 4516 4525 4506 4521 jj )> " i w. + 6:31 +6: 25 -0: 096 ... I ... Nil. J) ?• ■ JJ jj j» jj jj 39-35 2645 09-74 47-18 30-66 '45-82 2908 11-64 34-18 '17-95 '08-43 24-2? |17-40 5712 1797 32 10 3083 13-96 5660 08-18 35-16 5667 25-87 )) JJ Jj i 55 44-151 1 at - ... JJ J> jj >f j» j) )J ) J JJ Jj " $9 jj jj jj jj jj jj JJ J) + 6:33 + 0-29! )J Jj i 55 44-28 44-12 jj Jj „ 33-2S!l8-7OO5-8O 53073893 0596 „ 16.14 00-75 46-88 33-491808 4707 „ 3142 16-8403-355000 35-880350 + 016162 + 01216:3 + 0-141614 1628! 1634 1642. 1627| 16|34 16 59 14 12^ 1627 ie;4i 1715 17121 17129 18,01, 18 06, 06-12 4719 0364 JJ J) 45-29 4503 4508 55 4414 " >; jj jj )j I :j H. M. 1806 - jj >t » i JJ JJ j jj S.T. J> JJ JJ ... ... jj jj " i J) „ " i „ JJ jj jj ?j j? J) + 025 + 019 + 014 " i 55 44-08 " . jj " „ 21 I w. + 6:28 —6-096 ... Nil. ..I .. I W 52-930607 19-80 5306 ... 200034 58'4S-63 ... 3430 „ 57741217 26O039-25 5344 2572 +0-07162 + 00216,3 + 00316 | 5 I ... 5313 34 32 2575 JJ J) jj jj 45-26 44-88 44-85 jj jj J) JJ J) i JJ ...... jj jj „ 23 w. + 6:3O7 -003 + 017 + 0-20 + 009 —6-096 i 55 59-24 Nil. j 1.3 17 18 18 L8 18 19 If) 19 19 58i 42 50 1 56:06' 20 53! 59!: |07i bi 5616 47-45 .30-96 '48 94 ,0507 02-69 4812 3077 39 99 0957 ;31-33 ,00-63 „ a » yt JJ JJ " jj R 43-32 2977 16;60,04; 70 5154 1719 -Oil 14jl 17-08 ... n )> 45-36 »» >> JJ JJ jj JJ jj I* » ;> » » jj jj jj jj J) JJ J) JJ " JJ )) JJ JJ JJ + 013 + 017 + 021 + 024 + 0-22 jj N jj jj jj i ... 1 55 55 59; l6. 59 V24 at 55 S.T. 5924 H. M. 1833 JJ JJ JJ JJ JJ „ 18-70 0410 5108 3863 2464 5143 „ 16-95! 02-53 4900|35-78 2170J4919 „ 002046-47 33-8221-76 0830 3411 „ 42-9029-27 16-37'04-33 5116 16 81 „ 541639-702613 1266 58-45 26-22 „ 21-2807-63 551543-33 30-50 55-58 „ 42-9029-54 1704!0510520917-33 -0-37162 -0-41 164 -012 17 1 — 0 13172 -04117 2 -014180 -0-15180 5106 !48-78 3399 1668 25-81 55-44 J7-18 j) jj jj jj ?: >» )? jj 4523 4533 45-11 4515 4506 45-11 4509 jj jj " JJ j) 55 55 55 5930 5930 !59-22 JJ jj jj jj jj » JJ )j 1 1 n jj jj , ,*) jj jj ■ J) + 0:20 jj " jj jj » I » ! J! „ I H - Mean of Observations Personal Equation of Observers Personal Equation of Telegraphist at Eesulting Diff. of Longitude betw Eoekyside given by the Hult C serrations on 28 Stars Eoekyside een Hutt 3hron. and Jid") o 17 45206 0384 0198 0 17 44-624

Hutt Obseryatoby —Appendix B.

Gk—No. 23.

BETWEEN WELLINGTON AND OTAGO.

•fl Observed Times of Transits by Solar Chronometer. Reduction to Instrumental Errors. True Meridian Transits by Chronometer. Transits at Hutt by Electric Signal. Reduction to Mean Wire at Ilutt. I* Si a* si. Correction to True Meridian at Hutt. Differenca of Longitude. %r ITT*.. _ o Wires. Date. Star. 3 Wires. o "r! I 1 2 a b o 3 s 1871. July 6 B.A.C. 5324 „ 5518 „ 5621 5808 „ 5844 „ 587G „ 6487 „ 6646 „ 6833 ., 6870; „ 5735 „ 5781 „ 5941 „ 5987 „ 6168 ,. 6209 „ 6263 ,, 6487 , 6528 , 6168 „ 6209 „ 6371 ,, 5227 „ 5284 „ 6107 „ 6168 „ 6263 „ 6487 „ 6528 „ 6575 6772 „ 6802 „ 6833 Jircle. w. 070 48-5 220 015 530 045 060 155 0925 49-5 175 510 44.0 295 450 270 405 185 005 210 330 02014-5 355480 15-529-5 O7O2OO 190325 19-5:320 29041-5 22-5350 04-5 185 025 475 37024-5 300175 15002-5 30-517-5 11-557-5 26-012-5 050520 46-5 34-5 ... 515 17-031-5 05018-5 46-5 31-5 26 0130 23-509-5 36-523-5 32-5190 10-5|57-75 520395 01047-5 23-5110 445 320 13-500-25 45-5 26-5 000 43 0 33 0 45 5 450 535 470 32 0 330 120 055 495 050 440 59-5 400 220 045 455 320 17-5 010 55-75 110 055 455 27-5 340 590 200 48-5 58-5 395 130 575 460 590 57-75 060 000 4625 180 590 52 0 355 510 290 455 270 08-5 180 847 9 20 9!29 957 1003 10 08 1143 12 08 12 38 12 44 9 33 9 40 10 00 1013 10 43 10 49 10 57 1130 11136 9'52 9.59 1024 721 729 9;35 9 44 9 58 10 31 1037 10 45 1118 1122, 1127 j330 14-2 47-7 294 198 32.1 3205 411 34 75 18-15 47-7 24-7 17-8 02-4 17-8 57-8 12-8 525 344 51-49 3102 18-4 31-9 13-5 09-75 2380 1905 58 05 39-7 476 11-4 32-25 ,00-75 -046 s -005 Nil. j i 9 10 12 12 12 9 9 10 10 10 10 e 7 9 9 9 10 10 10 11 11 11 47 20 29 03 08 43 08 38 44 33 40 00 13 43 67| 30 36 52 21 20 35 44 58 31 87 45 18 22 27 ,32-771 13-967 47349 29-278 19638 31960 31-660 40-785 34415 18040 47-797 24-876 18-078 02-551! 17-954-! 57-916! |12-935 52786 34-682 51529 31053 18434 31401 13385 09293 23437 18-642 57932 39574 '47190 11-255 !32096 !OO6O7 Circle. E. E. 160 035 510 38-526-5 8 „ 57-0 445 320 19-5:070 9 „ 300 175 050 530:40-5 9 „ 01-5 475 33-5 200 9 „ 040 505 380 245 115 9 „ 170 035 50 0 36-5 23-5 9 „ 150 022549-5 37024011 „ 230 110 585 46-534-511 „ 170 045 525 395275 12 „ 040 500 3625 22-5 08-5 12 W. 370 520 06-5 21-535-5 9 „ 180 305 143-5 560 ... 9 „ 115 !240 365 490015 9 „ 545 075 210 340470 9 „ 100 235 365 49-5,02-510 „ 485 02-5 165 310450 10; „ 045 180 31-5 45-5 58-510 „ 450 57-5 105 £3-5 360 11 „ 270 39-5 52-5 !O5O17-511 „ 435 565 095 225 355 9 „ 215 35-5 495 J040180 9 „ 095 235 370 '51004-510 „ 205 350 490 040 185 7 31-5 44 0 570 7 „ 59-0 130 270 41-555-5 9 „ 155 285 415 '55-0080 9 „ 09-75 23-5 365 '50-5 04-0 9 „ 510 035 160 28-5 41-5 10 „ 32-5 450 57-5 110-523-010 „ 390 520 05-5 !l9-5 33010 „ 04-5 170 295 142-0 54-511 „ 25-5 38-5 505 J03'015-011 545 065 185 31-043-511 385 19-5 530 335 245 365 370 46-5 39-5 22-5 21-5 560 49-0| 340 49-5, 310 45-5 23-5 !050 '22-5 '04-0 |510 040 440 41-5 '55-0 !505 '28-5 110-5 19-5 |42-0 m-o 31-0 265 :070 200 11-5 235 240 34-5 27-5 08-5 355 8 9 9 9 9 11 L2 12 0 9 9 9 10 10 10 11 LI 9 9 LO 10 11 11 11 29 02 12 30 45 .-,0 50 20 20 10 22 48 55 25 32 30 13 IS 35 41 06 03 11 L7 26 40 14 19 28 00 ot 09 ,511 320 05-2 47-49 37-7 501 49-55 58-7 522 3625 065 4336 3G-5 20-8 364 16-7 31-6 105 523 09-5 49-7 371 49-4 31-39 27-2 41-7 3683 161 57-7 05-8 29 5 505 18-8 Losing. 164 +0200 + 2908 + 2910 + 2911 + 2910 + 2910 + 2-910 +2-911 + 2-911 + 2-912 + 2910 + 2-908 + 2-906 + 2-906 + 2-908 + 2908 + 2-907 + 2900 + 2-908 + 2-908 + 2 910 + 2908 + 2908 + 2910 i +2 908 > +2910 + 2-908 '+2908 |+2-908 > +2-908 1+2-907 > +2908 + 2-907 + 2 908 —013 -014 -023 -005 -013 -Oil —0-30 -024 -0 24 -010 + 013 000 —0-21 + 004 + 007 + 015 + 011 —0-20 —0-21 -001 -002 -003 + 004 -025 —008 -012 -006 -026 -023 + 0-06 —020 -019 -019 0 17 44-649 44-937 45030 44-838 44918 44860 44-921 44 956 45-087 44 800 44545 44631 44-483 44908 44741 44-480 44-560 45203 45289 45126 44-408 44405 45-151 44853 45123 44-725 44-860 44-680 44-752 44-557 44663 44513 44-725 JJ jj >J JJ >j JJ JJ JJ JJ II JJ )) )' II JJ JJ Jj " JJ JJ i ;> " >» n 11 Jj JJ jj " JJ U jj n jj jj J J JJ J» jj >> tt n jj ii 11 JJ JJ Jj " JJ JJ it n ii jj ii JJ JJ jj " )J JJ : || it >j jj jj JJ JJ " " JJ JJ ' |) n jj jj jj JJ JJ Jj 11 " r " jj it jj a )J E. + 0-31 -0-017 JJ w. 166 +0210 „ +0209 „ +0-209 „ +0209 „ +0209 „ +0207 „ +0209 „ +0209 „ +0209 160 +0194 „ +0193 „ +0193 164 +0-200 „ +0200 „ +0200 „ +0-200 „ +0200 „ +0200 „ +0200 „ +0200 „ +0200 „ +0200 „ +0200 n it Jj it >t jj M JJ JJ jj JJ JJ ,01-5 470 02-5 450 58-5 360 17-5 355 180 04-5 18-5 570 55-5 080 040 41-5 230 33 0 545 15-0 435 it ii jj tl 11 J> jj jj " )) I » jj u 11 JJ jj „ JJ ?) it jj ?) 11 JJ jj jj JJ jj tt 11 JJ Jj J> jj jj JJ jj jj 11 11 JJ JJ jj jj I » jj it 11 )» JJ JJ jj » jj it JJ JJ „ 21 JJ "W. 01-5 505 020 395 38-5 510 4675 240 055 155 370 5775 255 +o"31 + O:O73 „ jj jj " n ' jj JJ JJ jj 460 02 0 48 0 41-5 570 51-5 32-5 140 200 46-5 070 360 JJ JJ >i it ii JJ >' „ 23 E. +d: 3i + 0:206 + 0!285 » " ii ti ti i) || JJ JJ JJ n " »» )) JJ JJ JJ JJ n I j) j) j» jj JJ JJ JJ n 1 M I » )> JJ JJ JJ JJ .*) jj j» >j Jj JJ 11 M : | n »» i> jj JJ Jf 11 •' ! " »> j» JJ JJ JJ ,, jj jj >> j) JJ JJ n II , jj >> i) Jj » , n ! jj j 'j » >> I H >j i i i i i i i i Mean of observations ... Personal equation of observers ... H o - 17 44799 0-384 Eesulting difference of longitude b Eockyside chronometer and o' 'Ot' tveen ', srvatic Rockyside and ', ms on 33 stars Hutt, gi' ren by \ o 17 44415 b« J. T. Thomson, F.B.G.S.

EOCKTSIDE ObSEBVATOET —APPENDIX C.

G.-No. 23.

REPORT RELATIVE TO MEASUREMENT OE LONGITUDE, &o.

10

Appendix D. Electric Difference of Longitude, Hutt and Eockyside Observations by Eockyside Observations Ditto ditto Hutt „ H. it. S. 0 17 44415 0 17 44624 Mean Longitude, Eockyside Observatory, by J. T. Thompson, 26 observations, weight 12850 0 17 44519 * 11 22 06190 ± 14 Longitude, Hutt ditto ditto ditto ditto Ditto ditto H.Jackson 36 ditto weight 25880 11 39 50709 11 39 50-730 ± 10 Mean Longitude of Hutt Observatory, 62 observations, weight 38 730 ... ... Difference of Longitude for Bearing, 235° 28' 535". Distance, 492157 feet • •* 11 39 50723 ± 0-82 — 35413 Longitude of Wellington Observatory 11 39 15310 ±0 82 J. T. Thompson, F.E.G.S. Henbt Jackson, P.E.G.S.