OBSERVATIONS FOR TERRESTRIAL MAGNETISM 



13 



Port Victoria, Make, Seychelles Islands. 



The Magnetic Observation Spot, which is in Lat. 4° 37' 13" S., and Long. 55° 27' 35" E., 

 is situated near the North-Eastern corner of Coral Island, a small artificial islet, built 

 chiefly of coral blocks lying off the south side of the centre of the pier, and used for 

 storing government coal. 



The position is marked by a square block of concrete, raised about six inches above 

 the ground, and inscribed " OBSERVATION SPOT. H.M.S. SEALARK, 1905. VARN. 

 2° 45' W." 



The exact spot is shown by the head of a copper rod, which is flush with the 

 concrete, and has a small hole in the centre; where the plummet should rest. 



There are several old rusted pieces of iron lying in the vicinity, but all are outside 

 the magnetic field of influence. 



The " Fixed Mark " employed is the pointed top of the outermost boulder off North- 

 East Point. Its azimuth from the Magnetic Station is N. 12° 02' 43" E. 



The magnetic elements observed at this spot on September 18th, 1905, were 

 as follows : 



Declination. 



2° 49' 13" W. 

 2° 40' 55-5" W. 



At 9 h. 26 m. A.M. 

 „ 3 h. 34 m. P.M. 



Inclination. 

 From 1 h. 22 m. to 2 h. 24 m. p.m., - 32° 12' 32". 



Horizontal Force. 

 From 10 h. 19 m. A.M. to Oh. 52 m. P.M. 



X' = 0-31 144 c.g.s. 



Cerf Island. 



The Magnetic Observation Spot, which is in Lat. 9° 31' 40" S., and Long. 50° 59' 39" E., 

 is situated on the westernmost of the four tidal sand islets forming Cerf Island, and is 

 separated by a narrow channel, dry at low water, from the islet with the oldest coconut 

 palms (13 in number) and most bushes (1905). 



There are a few bushes of Sccevola on the observation islet, and a fairly large pool 

 of fresh water. The magnetic position is situated with the centre of this pool bearing 

 N. 15° W. (mag.), distant about 45 yards. 



There are no very definite or permanent objects to mark the situation accurately; 

 but the following true bearings may be given: 



Southernmost coconut tree on near islet 

 Northernmost ,, „ ,, 



Distant boulder on outer reef 

 „ ,, (near above) 



Single coconut tree, distant about 1 mile 



S. 48° 35' E. 

 N. 81° 18' E. 

 N. 55° 27' E. 

 N. 54° 57' E. 

 N. 1°01'W. 



