( 1107 ) 
1 hope you intend to publifh a Dtfcourfe, in purfiiance 
of that Mdp^ which I Ihall be glad to fee : Expedting to 
find, therein, divers confiderable ELemarks, by you ob- 
ferved in the Southern Seas 5 where (perhaps) never any 
had been, fo far Southward, as you have been. 
The Doftrine of the Magnet^ hath been moftly im- 
proved at Grefifam College, ( or by thofe related thereun- 
to, and there converfant,) for an Age or two laft paft ^, 
as Blagrave^ Gmter^ Gellihrand^ GilbtrP^ Norwood^ Wrig,k^ 
Brigs, Fofter, &c. and (of late) hy yourfelf If I have 
miftaken foEne Names, or mifplaced them^ or omitted 
others 5 you will be able to reftifie it 
I have given fome Intimation of it (but very Imperfefit* 
ly ) in a Letter of mine, infehed in the TranfaSions for the 
Month of December 1701. where ( beiide divers Literal 
Faults) they have unhappily mif*printed 1635, inftead ok 
1625. 
For it was about the beginning of the Reign of King 
Charles tliQ Firft, thatMr Gellihrmd f if I have not been 
mif-informed) caufed the Great Concave Dial to be erefted 
in the Frivj Garden at White-hall^ (which, I think, is yet 
remaining ^ ) v/ith great care to fix a true Meridian-Line ^ 
and with a large Magnetick, Needle^ (hewing its Variatio^s^ 
from that Meridian^ from time to time. 
I think it were not amifs, if exad Obfervation were novv 
made, whether the MerrW?^;^ be. Now, juft the fame as it 
was Then. For it is very poffible, that the Pole of the 
Earth, may, in time, fuffer fome little Variation* (which 
may not readily be difcerned,) which may caufe an Alte- 
ration of the Meridian'^ Line. And this, if fo, will be 
more difcernibie Nearer the Pole, tnan Farther oE , 
And though fuch Provifion (as was but now faid^ were 
made at yihite-hall, for obferving 'the Needles Variatica 
from the true North 5 and, though f no doubtj) notice < 
have been given many times f there and ellewhcrej what 
the Variatioa hath been at fuch times : Yct^ I doubt, no 
I . Kkkkkkk 2 B.e~ 
