of Van Diemen's Land. 99 



The convergence of the meridians of Brown Mountain and 

 Dromedary is computed as follows : — 



o / /f 



Latitude of Dromedary ... 42 42 38-8 from local observation. 

 Lat. of BrownMomitain... 42 36 7-7 ditto ditto 



Length of line 117825 feet. 



Beariiag 69° 6' 25"-2 



Log. to = 206264.8 = 



5-3144251 



Log.i 

 a 



2-6801158 



Log.d = 117825 



5-0712374 



Sin. 2! = 69 6 25-2 



9-9704622 



Sec. I = 42 42 38 8 



0-1338385 



Sin. i (L+0 42 39 20-5 



9-8309677 



Seci(L— 3 16-7 



0-0000002 



Log 1002-4 



= 3-0010469 



= 16 42-4 Angle of convergence. 

 The above calculations of Azimuths and Latitudes wholly 

 depending on the local observations, I proceed to give the 

 calculations for the same, derived from the latitude of Hobart 

 Town, through the tri angulation. The following is a copy 

 of Mr. Sprent's Keport on the observations made by him at 

 his Observatory in Church-street, 



Mr. Sprent's Keport. 



" The following results are derived from observations 

 upon '^ Octantis, for ascertaining the latitude of my obser- 

 vatory. They are obtained from 108 elevations of that star 

 taken with the Altitude and Azimuth circle. The error of 

 the chronometer was ascertained by transits of the sun or 

 stars on my meridian, taken as near the times of observa- 

 tion as convenient. 



The observations were taken in groups of four, viz. : 

 four with instrument direct or reading Altitudes, and four 

 with the instrument inverted or reading Zenith distances. 

 They have been calulated in sets of two direct and two 



