VOL. v.] PHILOSOPHICAL TRANSACTIONS. 513 



4° 15'. In the year 1628, if I remember right, I found it near one degree west- 

 ward : which declination was affirmed by the learned Petre Cniger (once my 

 worthy preceptor) to have been, about the beginning of this age, or the end of 

 the next foregoing, 8° 30" eastward ; the same Cniger also, making use of that 

 eastern declination in describing all his dials, as may be seen in the tract he has 

 written on that subject; though it be not certainly known, by whom, and in 

 what year that observation was made. 



Further, it appears by our more recent observations, that this declination of 

 the loadstone does here, at Dantzic, almost every seventh year, or, to speak 

 more precisely, every sixth year and seven months, increase to one whole degree, 

 and so each year, to 9' 6'\ Which is sufficiently confirmed by the observations 

 made at Limehouse near London, by those three famous Englishmen, Burrow, 

 Gunter, and Gellibrand : Of whom the first found the declination, A. J 580, to 

 be J 1° \6'; the second, 5° 36' 30'', An. l622; the third, 4* 3' 30", An. J 634. 



Lastly, it being now certain that the needle's declination varies in one and 

 the same place; the accurate observations of the subsequent years will show 

 how far this deflexion will proceed, and where, and in what distance from the 

 true meridian, the very bounds of this declination really are ; especially, whether 

 this libration and variation will be the same, and regular at all times and in all 

 places; or whether, and how long, it will remain stationar}\ All which parti- 

 culars, that they may be accurately discovered, is a thing very much desired. 

 Possibly considerable speculations and researches may arise from such observa- 

 tions. As for me, I am almost of the opinion, that this magnetical diversity 

 comes from the motion of the earth. Doubtless, as there is a certain libration 

 in the moon, so it is not absurd to me, to hold a kind of libration in the earth, 

 from the annual and diurnal motion of the same. For that the cause of this 

 declination and variation of the loadstone is inherent in the stone itself, or to 

 be ascribed to aethereal corpuscles, is not imaginable by me; nor can I yet de- 

 vise any cause of those appearances, except we impute them to the globe of the 

 earth, and the variation of the meridian. 



I lately received from a person residing on the side of the Baltic sea, a piece 

 of amber, which is so soft, that I printed my seal on it. It is yellowish as most 

 amber is ; transparent and burning as other amber ; but its scent stronger, as if 

 it were a kind of glutinous bitumen; and yet it has been cast up from the sea 

 this year, and was found among other pieces. His brother, a very credible per- 

 son, related at the same time, that he had possessed a small piece of amber, 

 soft on one side, and very hard on the other, wherein lay buried a fly. 



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