of Van Diemens Land. 101 



It is to be observed tbat in tbe observations from wliich 

 the above results were obtained, refraction forms no function 

 in the elements for the calculation. 



The elongations gave for my Meridian mark the following 

 results, — 



Instrument at zero on the mark, or 



Beading of the instrument South .... 180 44"9 

 That is the mark is to the Eastward of 



North ; 



I took this month, (August 1853), 36 angles of n Argus 

 with the Meridian mark, using the chronometer. They 

 gave the following results, — 



4 -"9 7 of arc 



Instrument direct. 



Instrument inverted 



12 Sets 180 8-3 



180 4-2 



12 „ 3-4 



4-0 



12 „ 4-98 



6-9 



36 Sets 180 5-56 



180 4-7 



.,. „ 4-7 





180 5-13 





Mean 



Agreeing very nearly with those derived from the greatest 

 elongations. 



By a series of small triangles connected with the main 

 triangulation, I find the difference of latitude between my 

 Observatory and the Magnetic Observatory — 30""41, 

 hence 42° 63' 25"-66— 30"-41=42° 51' 55"-25 = latitude, 

 of Magnetic Observatory, and the difference of latitude 

 between my Observatory and the Hobart Town Semaphore 

 is + 43-48, hence 42°52'25"-66 + 43-48 = 42° 53' 9-"14 

 latitude of Hobart Town Semaphore. 



Bearing of Meridian mark from my Observatory. . . N. 5 E. 

 Angle of mark with Eumney's Hill 81 3 31*2 



Bearing of Eumney's Hill from my Observatory... N. 81 3 36-2 E. 



