THE NEW ZEALAND GAZETTE. 231

8. Wellington.
   Date.

9. Dec. 26

Dec. 27

1875. Jan. 11

Jan. 13"

Operators.
Pat W sends to D at B
Dat B sends to Pat W
Pat W sends to C at B
Cat B sends to Pat W
Pat B sends to Dat W
Dat W. sends to Pat B
Pat B sends to Dat W
Dat W sends to Pat B

Resulting Diff. of Longitude. Time, determination by.
W east of B
M. S.
9 52.96
9 52.96
} P at W; Dat B
"
9 52.59
9 52.50
} P at W; Cat B
"
9 51.89
9 51.80
} P at B; Dat W
"
9 52.16
9 52.08
} P at B; Dat W

Mean difference of longitude W east of B ... 9 52.37
The discordances in this case are considerably greater than the others. I attribute this to the
character of the instruments used at W. In the first place, the transit instrument had no micrometer;
consequently the observations spread over a long time. I was occupied nearly two hours one night
with the transit of a single circumpolar star. This necessitated a certain amount of reliance on the
steadiness of rate of the chronometer employed-viz., Molyneux No. 2082; but the performance of
this chronometer was bad, its rate being unsteady and very large, between 20 sec. and 30 sec. daily,
and it is likely that errors of some consequence were thus introduced.
The first result on 13th January is the mean of two sets, in which the decimals of seconds were s-10
and s-23. On 26th December three clock-stars only were observed at W, instead of the usual number,
six at least; but the observations were good, and full weight has therefore been given to the night's work.

9. Auckland.
   Date.

10. Dec. 26

Dec. 29

1875. Jan. 5

Operators.
Hat A. sends to Dat B
Dat B sends to Hat A
Hat A sends to Pat B
Pat B sends to Hat A
Hat A sends to P at B
Pat B sends to Hat A

Resulting Diff. of Longitude. Time, determination by.
A east of B
M. S.
9 52.75
9 52.61
} H at A; Dat B
"
9 52.32
9 52.05
} H at A; P at B
"
9 52.37
9 52.06
} H at A; P at B

Mean difference of longitude A east of B... 9 52.36
It is necessary to remark that as Mr. Heale has not sent me his reductions for examination, I
cannot vouch for their accuracy; but the results give no reason to suppose that they are otherwise
than correct. The time observations at A were taken with a small (two-feet) portable transit instru-
ment by Troughton and Simms, kindly lent me by Messrs. Coates and Co., of Christchurch.

Note on the Longitude of Wellington Observatory and the Latitude of Burnham.
10. Although the extra meridianal observations of the moon for longitude, taken at Burnham with
the altazimuth in November and December last, have not yet been reduced, an approximate longitude
has been worked out from the observed meridianal transits of the moon. According to this approxi-
mate determination, the longitude of the transit-pier at Burnham appears to be 11h. 29m. 12s. 44 east
of Greenwich. The errors of the moon's tabular right ascensions have been taken into account in this
reduction; but the result remains affected by the personal equations of the observers, both as regards
transits of stars and transits of the moon, which have not yet been ascertained. Though the determi-
nation, therefore, can only be regarded as approximate, it may nevertheless be interesting to compare it
with those previously arrived at by others, and given in the documents enumerated in the foot-note.*

1. The approximate absolute longitude of the transit-pier at Burnham
   obtained as above by ourselves is
   Wellington Observatory transit-pier east of the Burnham transit-pier
   by galvanic signals

H. M. S.
11 29 12.44 E.
9 52.37

Palmer's approximate longitude of Wellington Observatory ... 11 39 4.81 E.
2. Adopting the longitude of Melbourne Observatory as fundamental, and equal to
9h. 39m. 54s. 80; and the telegraphic difference of longitude from Melbourne to Sydney
Observatory as +24m. 55s. 81, we get 10h. 4m. 50s. 61 as the longitude of Sydney Obser-
vatory. The chronometric difference from Fort Macquarie (Sydney), to Pipitea Point
(Wellington), determined by Captain Stokes, R.N., is +1h. 34m. 15s. 53. Hence we
have,-

Longitude of Sydney Observatory...
Correction to Fort Macquarie
Pipitea Point, East of Fort Macquarie
Correction to Wellington Observatory
Stokes's longitude of Wellington Observatory
H. M. S.
10 4 50.61 E.
+2.63
+1 34 15.53
-2.88
11 39 5.89 E.

• Parliamentary Paper, 1871, G. No. 23. Supplement to the New Zealand Gazette No. 12, 1871. Report by Dr.
  Hector to the Colonial Secretary, 9th September, 1874, enclosing Memorandum on Longitude by Captain Nares, R.N.