MAGNETIC SURVEY OF TASMANIA. 93. 
The prevailing rock is a coarse sandstone of Mesozoic age. 
Azimuths.—Apex of gable of a small shed in front of a 
larger shed (Railway shed, see figure III., plate IV.), a, 
77° 16‘ 9/'. Church spire, 0, 80° 7! 53’. Left edge of 
plateau of Table Mountain, C, 1099 35' 54'’, Ball on top 
of round windmill, d, 1319 15''14'" 
Magnetio statton from M.S. mark.—[{No exact record of 
angle of elevation.] Horizontal distance, 27:1 feet; 
azimuth, 29 28' 3". 
Directions for finding M.S. mark.—In the solid rock. 
Looking south-east over Lake Dulverton from the point 
where the main road from Hobart to Launceston crosses the 
lake, the M.S. mark is on the left shore of the lake, on the 
property of Mr. Weeding. The mark is near to one of the 
largest cayes on that shore. From the mark the azimuth 
of an unu™ially large she-oak is about 29° 53’. The points 
a, b, C, d adove should serve to identify the site. 
Statien.—Southport. Lat. 43° 25° 17". Long. 9h. 47m. 
52°8s. ; 
Date. | Time. | Element. 
March. f | 
2 | 4:96-4:44 pam. | Declination | 11° 44/1" 
Vibration 11°28-11-39 | : 
2 au i Horizontal pee 
Deflection 9-30-10°30 | § Force 1932 
| am, 
3 ‘(1035-11-45 a.m. I 
12°10-1-35 p.m. € Dip. 72° 24' 10" 
3°0-3°50 p.m. 5 
nh Sats f be 
At the time of selecting the site, it appeared that the 
underlying rock was mudstone of Permo-Carboniferous age, 
but from the magnetic results obtained it seems extremely 
probable that there must be an intrusion of highly magnetic 
greenstone (diabase) near to the site. The M.S. mark was 
embedded in cement below the level of the ground. 
_ The determinations of the magnetic elements at this sta- 
tion are valueless for the purposes of the survey. 
