2 



Transactions of the Sonth African Pliilosopliical Societij. 



^ 2. I)icli)iatioii. 

 The following is a list of 

 Cape : — 



Date. Observers. 



1751. La Caille 



1770. Ekeberg 



1774. Bavley 



1774. Ekeberg 



1775. Wales 



1775. Abercrombie 



1776. Bayley 



1780. Bayley 



1791. Vancouver 



1792. Dentrecasteaux . . 



1818. Freycinet 



1836. Eitzroy 



1839. Du Petit Thouars. . 



1840. Ross 



1841. R. A. Detachment. . 



1842. R.A. 



1843. R.A. 



1844. R.A. 



1845. R.A. 



1846. R.A. 



1847 



1848 



1849 



1850 



Eeb. 6, 1851. Sir Thomas Maclear 



1852 



1853 



1854 



1855 



1856 



Jan. 1857. 



Oct. 1857 



March 1858 



Aug. 1871. Stone 



Sept. 1871. Stone 



Nov. 1873 



Sept. 30, 1874 



Jan. 31, 1890. Preston 



Dec. 29, 1894. Combe 



Jan. 11, 1895. Einlay 



Oct. 23, 1897. Einlay 



Oct. 2, 1899. Beattie c^' Morrison 



Aug. 19, 1900. Beattie & Morrison 



Dec. 1900. Beattie & Morrison 



Dec. 1900. Beattie & Morrison 



From the above results the 



follows : — 



Period. 

 1751 to 1840 

 1S41 ,, 184() 

 1S43 ,, 1854 

 1854 „ 1S73 

 1873 ,, 1890 

 1890 „ 1900 



the determinations of inclinationtat the 



Dip. 



43° 



0' 



44 



25 



45 



37 



44 



29 



45 



19 



4() 



21 



46 



31 



46 



46 



48 



30 



47 



25 



50 



47 



52 



35 



53 



06 



53 



08 



53 



09 



53 



12 



53 



19 



53 



36 



53 



31 



53 



33 



53 



41 



53 



47 



53 



52 



53 



58 



54 



02 



54 



04 



-54 



09 



54 



19-6 



54 



24-5 



54 



23-9 



54 



23-0 



-54 



36-4 



-54 



29-3 



-55 



45-4 



-55 



34-9 



55 



56-3 



56 



6-0 



57 



15-2 



57 



50-0 



57 



52-0 



58 



07-0 



58 



31-0 



58 



38-9 



58 



39-7 



58 



41-1 



Authorities 



Remarks, 



Erom Sabine's 'Magne- 

 tical and Meteorolo- 

 gical Observations at 

 the Cape of Good 

 Hope,' vol. 1. Mag- 

 netism. 



Admiralty hydrogra- 

 phic records. 



Sabine. 



The resuhs for 1841 to 

 1846 inclusive are the 

 mean of observations 

 taken as a rule twice 

 weekly, four hours 

 before and four hours> 

 after noon. 



1 



Dip-bookRoyalObserv 

 C. of G. Hope. 



The results for 1852- 

 1857 inclusive are the 



. mean of observations 

 taken twice weekly, 

 morning and after- 

 noon. 



Reise der Kovara. 



' Dip-book R. 0., C. of 

 ^ G. Hope. 



( CluiUoifier Report, 

 1 Narrative ii. 

 Voyage of the (iazelle 

 I U.S.Coast and Geodetic 

 Survey, Bull. 23. 



R.O. Records, C. of G.^ 

 Hope. 1 



R. 0. Records, C. of G. 

 Hope. 



With Dip Circle 

 by Dover. 



With Dip Circle 



142, by Dover. 



secular variation of inclination is as 



Secular Variation. 

 ()-94' annual increase of south inclination. 

 5-45 ,, ,, ,, 



5-10 „ 

 2-20 „ 

 4-90 „ 

 7-80 „ 



