he
understanding of the common people and their manner of speech, just as
nurses are accustomed to adapt themselves to infants, and not to go into
every unnecessary detail. Thus in Gen. i. v. 16, and Psal. 136, the moon is
called a great light, because it appears so to us, though it it is agreed
nevertheless by those skilled in astronomy that many of the stars, both of
the fixed and wandering stars, are much greater. Therefore neither do I
think that any solid conclusion can be drawn against the earth's mobility
from Psal. 104, v. 5; although God is said to have laid the foundations of
the earth that it should not be removed for ever; for the earth will be
able to remain evermore in its own and self-same place, so as not to be
moved by any wandering motion, nor carried away from its seat (wherein it
was first placed by the Divine artificer). We, therefore, with devout mind
acknowledging and adoring the inscrutable wisdom of the triune Divinity
(having more diligently investigated and observed his admirable work in the
magnetical motions), induced by philosophical experiments and reasonings
not a few, do deem it to be probable enough that the earth, though resting
on its centre as on an immovable base and foundation, nevertheless is borne
around circularly._

_But passing over these matters (concerning which I believe no one has ever
demonstrated anything with greater certainty), without any doubt those
matters which you have discussed concerning the causes of the variation and
of the magnetick dip below the horizon, not to mention many other matters,
which it would take too long to speak of here, will gain very great favour
amongst all intelligent men, and especially (to speak after the manner of
the Chemists) amongst the sons of the magnetick doctrine. Nor indeed do I
doubt that when you have published these books of yours on the Magnet, you
will excite all the diligent and industrious shipmasters to take no less
care in observing the magnetick declination beneath the horizon than the
variation. Since (if not certain) it is at least probable, that the
latitude itself, or rather the effect of the latitude, can be found (even
in very dark weather) much more accurately from that declination alone,
than can either the longitude or the effect of the longitude from the
variation, though the sun itself is shining brightly or all the stars are
visible, with the most skilful employment likewise of all the most exact
instruments.