22 



TRANSIT OF VENUS, 1874. HONOLULU. 



between the circle-reading corrected for level and refraction and the adopted 

 zenith point. 



The remaining columns require no explanation. 



5 7 . Summary of co- latitudes. 



As was to be expected with so small an instrument, the flexure is insensible. 

 It is to be remarked that the lines of sight of the low northern stars passed 

 pretty closely over the summits of the mountains. The latitude derived from 

 these stars differs 0" - 8 from the general mean. The adopted latitude of the 

 altazimuth pier is 21. 17'. 56" - 9 N. It is probable that the meridional devia- 

 tion of the plumb-line from the vertical is considerable, as the sea is deep 

 to the southward, and the axis of the mountain range only 4 or 5 miles to 

 the northward. 



ON THE LONGITUDE OF THE STATION AT APUA. 



(1.) Longitude of Honolulu Station from the Observations of the Moon on the 



Meridian. 



58. In Table IV. are given the observed transits of the Moon over the 

 center wire as obtained from the mean of all the wires observed. When all 

 five wires have been observed, the observation has been treated as if it were 

 of a star, the sum of the instrumental corrections always being a fraction of 

 a second. For the incomplete transits, of which there are five, the reduction 

 of each side wire to the center wire has been obtained by multiplying the 

 Equatorial interval by the factor 



(i + m) . sin z. 

 Sin d . sin z 1 . 



where m is the increase (in seconds of time) of the Moon's R.A. for the 

 transit over a meridian distant 1 s of terrestrial longitude, as given in the 

 section Moon-culminating Stars in the Nautical Almanac ; z is the Moon's 



