TrcAtife ^/BODIES. 249 



pick; and D, a point in the earth near the pole, unto 

 which in the laid interle&ion the needle tendcth, in 

 (lead of looking dire&ly to the pole, whereby itma- 

 keth variation from due north. I fay then that the 

 variation of a needle near the equator in the point B, 

 looking upon the point D ; cannot be fo great and 

 fenfible, as the variation of a needle in the Tropick 

 C, looking upon the fame poinc; fince the angle 

 D B A> which is made by the variation of the firli, 

 is leflethen the angle D C A, which is made by the 

 rariation of the latter needle, nearer the pole. 



But becaufe it may happen > that in the part? near the equa- 

 tor, the variation may proceed from fbme piece of land , not 

 much more northerly then where the needle is; but that bearcth 

 rather eagerly or wefterly from it;and yet Gilbcrs aflertion go- 

 eth univerfally, when he faith the variations in fouthern regi- 

 ons arc leflethen in northern ones; we muft examine what may 

 be the reafon thereof. And prefently the generation of the load- 

 tfone fhcweth it plainly : for feeing the nature ot the loadtfone 

 proceedeth out of this , that the funnc worketh more upon 

 the torrid zone, then upon the poles; and that his too ftrong 

 operation is contrary to the loadftone, as being of the nature 

 of fire; it followeth evidently, that the lands of the torrid zone 

 cannot be fo magneticall (generally fpeaking)as the polar lands 

 are; and by conlequence, that a Jeffer land near the pole > will 

 have a greater effect, then a larger continent near the equator: 

 & likewife a land further off towards the pole, will work more 

 ftrengly then a nearer land which lyeth towards the equator. 

 The fcventh queftion is , Whether in the fame part of the 

 world a touched needle may at one time vary more from the vvhcihcunthe 

 true north point, and at another time IclTe ? In which Gilbert '-"ic parr O fn e 

 was reiblutefor the negative partrbut our latter Mathematicians 



are of another mind. Three experiences were made near Lon- * v : ^ l j. m va - " 

 don in three divers years. The two full 42.yearcs diftanc from the north,"*! : 

 one another; and thethird 12 yeares diibnt from the fccond. ^ t fl a c iv> ' hcrcia ' c 

 And by th-cm it is found, that in the fpace of 54 years, the load- 

 ftone hath at London diminiflied his variation from the north, 

 the quantity of 7 degrees and more. But fo that in the latter 

 years the diminution hath fcnfibly gone fafter then in the former 



