( 1037 ) 
North, in its Horizontal Pofition, ) hath alfo a Direfti- 
on of Altitude above the Horizon. And (if duly poifed 
about an Horrizontal Axis) will point to a determinate 
degree of Altitude or Elevation above the Horizon, in 
this or that place refpeftively. Of which Difcovery 
( though made fo long ago J I do not find that much 
life hath hitherto been made : that, of its Horizontal 
Declination, being more (erviceable. 
Tis alfo an EngUJh Obfervation^ That not only a 
Magnetic^ Needle, but any Piece of Jr^^;^ (if kept long in 
the fame Pofture,) ihall of it felt contrada Polarity. As, 
for inftance, an Ered Bar in a Window, (after long con- 
tinuance m that Pofition, will (if duly poifed) be found, 
with its upper end, to point toward the North 5 ("and 
Southward with the other end.) And, if afterwards it 
be continued long in a contrary Pofition, it will attain a 
contrary Polarity. 
And Mr Gilherfs Notion, (of the Earths whole Body, 
being but one Great Magnet ^ and, leifer Magnets being 
fo many TerrellaV^ fympathizing with the whole,) is En- 
gUJf) alfo. 
It hath been obferved alfo. That a Magnetick Needle, 
if heated Red-hot, will lofe its Polarity : And, if then 
cooled in a contrary Pofition, will acquire a contrary 
Polarity. 
It hath alfo been obferved (if I have not been mif-in- 
formedj by our Englip Mariners, f and, I think, more 
than once, ) chat, upon a great Flafti of Lightening ( at 
Sea ) their Magnetick Needle hath loft its former Polari- 
ty 3 and contrafted the contrary ^ (pointing the wrong 
way, and direfting the Mariner to a wrong Gourfe.) 
And ( in General ) the Doftrine of Magrsetlfm hath 
been more improved by our £;^^/i/7; Natural ifts, than (for 
ought I know ) by any other Nation. And, it fomeof 
our Gref-hamites would take the pains to give us a true 
Hiftory of thefe fand the like) improvements 3 it would 
b^ 
