GEOGEAPHIOAL POSITIONS. 



9 



ENGLAND, SOUTH COAST. 



LAT. N. 



Portsmouth, Observatorj^ 



Scuthsea Castle 



Calshot Castle 



Southampton, Observatory 

 Southampton, West Pier 

 Hui-st Castle, East Light... 

 Dunnose, Station in the 



Survey , 



St. Catherine's Lighthouse, 



Isle of Wight 



Needles Lighthouse 



Christchurch Head 



Anvil Point, Lighthouse... 



Poole Church 



Portland, Upper Lightho. 



Lyme Cobb 



Hob's or Hope Nose 



Berry Head, Flagstaff 



Dartmouth Harbour, St. 



Petrox Church 



Start Point, Lighthouse ... 

 Bolt Head, Signal Station 

 Eddystone Lighthouse ... 

 Mewstone, near Plymouth 



Soimd 



Plymouth, Smeaton's 



Tower on the Hoe ... 



Drake's Island, East end 



Lighthouse, on the West 

 end of Breakwater ... 



Meridian Tablet, on the 



Breakwater [2] 



Penlee Beacon 



Eame Head, Flagstaff 



Dodman or Deadman Point, 



Flagstaff 



St. Anthony's Head, Light- 

 house [3] 



Pendennis Castle, Flagstaff 



St. Kevern Steeple 



Blackhead, Flagstaff 



Lizard, East Lighthouse... 

 St. Michael's Mount, Tower 

 St. Paul's Steeple, Moimt's 



Bay 



St. Leven's, or Guethens- 



bras Point, Flagstaff. 



Wolf Eock, Lighthouse ... 



Land's End House 



Longships Lighthouse 



SciUy Islands, St. Agnes' 

 Lighthouse 



St. Mary's Flagstaff, at 

 the Fort 



iV J. O. 



50 48 3 

 50 46 39 

 50 49 9 

 50 54 49 

 50 53 42 

 50 42 27 



50 37 6 



50 34 30 

 50 39 40 

 50 42 38 

 50 35 30 

 50 42 46 

 50 31 17 

 50 43 11 

 50 27 40 

 50 23 55 



50 20 29 

 50 13 18 

 50 13 5 

 50 10 49 



50 18 20 



50 21 50 

 50 21 15 



50 20 2 



50 19 59 

 50 19 20 

 50 18 53 



50 13 20 



50 

 50 

 50 

 50 



8 25 

 8 44 

 3 7 

 20 



49 57 35 



50 6 55 



50 5 20 



50 2 10 



49 56 43 



50 3 50 

 50 3 57 



49 53 31 



49 54 50 



LONG. W. 



AUTHORITIES. 



58 

 10 



16 50 



18 22 

 24 6 

 24 23 

 32 56 



1 11 50 



17 47 

 35 25 

 44 45 

 57 30 

 59 IB 



27 18 

 56 

 28-43 



28 50 



3 33 54 

 3 38 28 



3 48 40 



4 15 53 



17 



17 10 



17 35 



18 



4 6 20 



4 9 30 



4 9 



4 9 27 I 18 20 



4 8 52 

 4 11 35 

 4 13 25 



4 48 1 



50 

 2 45 



5 



6 



12 



8 



15 



5 



28 37 



5 32 43 



5 40 46 

 5 48 27 

 5 42 50 

 5 44 45 



18 40 



18 40 



19 



6 20 41 ; 19 15 

 6 19 15 



The Grand Trigonometri- 

 cal or Ordnance Survey of 

 England, &c. 



Eemabks. 



As a matter of curiosity it 

 may be mentioned that, by ela- 

 borate computatious, the Equa- 

 torial radius of the earth is 

 found to be 20,926,500 feet ; the 

 Polar radius 20,855,400 feet; 

 and a mean degree of the meri- 

 dian contains 364,616 feet. The 

 ellipticity of the earth is as 294 

 is to 295, and the mean density 

 is 5-316. 



These geodetic operations 

 have now been carried to such 

 a degree of refinement, that the 

 varied density of the strata in 

 different regions has a marked 

 effect on their results. It has 

 been argued by Archdeacon 

 Pratt (of Calcutta) that this is 

 sufficient to cause a deflection 

 of from 20" to 30" in the perpen- 

 dicularity of the plumb-line ; 

 aad this of course affects, in a 

 corresponding degree, the deter- 

 minations of the exact latitude, 

 and with that the true iigxire of 

 the earth. 



s 



