10 



employed, independent of 110 astronomical observations, and 

 a triangulation. The whole of these observations were made 

 from the year 1843 to 1846, and in order to obtain the 

 corresponding observations of the moon culminating stars, 

 previous arrangements were made at Greenwich, Edinburgh, 

 Cambridge and Oxford. The lunar observations were after- 

 wards placed in the hands of Mr. Eiddle, head Mathematical 

 Master of the Nautical School at Greenwich, for reduction, and 

 the whole series were reduced, and a paper drawn up from 

 the results by Captain Shadwell, for the Astronomical Society, 

 which gave for the longitude of Hobart Town, 9h. 49min. 29*6 

 sees. 



Since the time this result was arrived at Captain Denham, 

 when stationed at Garden Island, sent an officer into these 

 waters for the purpose of confirming the longitude of Hobart 

 Town. The mean result of all observations made at that 

 time, gave for the longitude 9h. 49m. 28 'Ss. being a small 

 difference of (0*8) — eight-tenths of a second. There remains, 

 however, still much doubt as to the correct geographical 

 position of any of the Australian colonies being correctly known. 

 Captain Kay thinks with the Astronomer Eoyal, that for 

 observing the forthcoming Transit of Venus, in December 

 1874 and 1882, they are not suited until better known. Mr. 

 EUery thinks differently, he considers the longitude of the 

 Melbourne Observatory as well known as that at the Cape of 

 Good Hope. The Sydney Astronomers believe the longitude 

 established at Fort Macquarie, Sydney Harbour, and at the 

 Observatory, Parramatta, by the late Sir Thomas Brisbane, 

 assisted by his computer and observer, Mr. Eurnker, and Mr. 

 Dunlop, to be the best known of any in these colonies. The 

 authorities for the establishment of the longitude of Fort 

 Macquarie, Sydney Harbour, and the chronometrical dif- 

 ferences of meridians employed in the determination of the 

 longitude for Hobart Town, from them, were very numerous. 



The determination of the latitude of any place is a much 

 simpler problem ; the latitude obtained by Captain Kay,was the 

 result of sextant observations by the method of circum-meri- 

 dional altitudes of the sun and stars. In their reduction, 

 Baily*s Tables and Formulae of reduction to the meridian, and 

 Ivory's Tables of refraction, with their correction for pressure 

 and temperature were used. Captain Kay thinks that the 

 latitude assigned to the observatory cannot be much in error. 

 If we consider the number of observations made and the large 

 amount of labour bestowed upon them, the authority connected, 

 and the result obtained, we have an equal right to consider 

 the geographical position of Hobart Town, as correct as any 

 of the Australian colonies. In all probability not one of the 



