63 
Proposed Correction to the assumed Longitude of 
the Sydney Observatory. 
By Jonny Tressurr, F.R.A.S. 
[Read before the Royal Society of N.S.W., 5 June, 1878.) 
vatory. Four methods may be mentioned for this determination, 
namely, the Sc aiactiated of chronometers, observations of moon 
culminations compared with corresponding ones at Gree awich, 
nam 
ee of moon-culminations. _ During the lniter part of 
year 1859, the Rev W. Scott, the then Government 
haiccaige: observed forty-eight orate transits of the moon 
ich; wa s the value 
in the Nautical aes ela the aincnisht Jahrbuch. During 
the year 1860 fifty other meridian transits were observed, namely, 
twenty-six of the first limb, and twenty-four of the second. ese 
likewise, compared with the tabular positions in the WNaztical 
Almanac, gave 10h. 5m. 6°84s. E. as the longitude. In the year 
1 ix h 
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at the Cape of Good Hope and Greenwich Observatories. 
appears from a discussion in the volume of ' es ‘8 dne = rrieriprermapneg 
limb, and eight of the second, observed at Greenwich and Sydney 
in 1859, the concltane s longitudes being respectively 10h. 4m. 
é . 4m. . E. has als 
transits of the first limb, and eleven of the second, observed at 
both places in 1860, with the respective results—10h. 4m. 45° op . 
a i . 
