ations_.

In a round[226] hollow wooden bowl, all the upper part of which is closed
with glass, a versorium is placed upon a rather long pin which is fixed in
the middle. The covering prevents the wind, and the motion of air from any
external cause. Through the glass everything within can be discerned. The
versorium is circular, consisting of some light material (as card), to the
under part of which the magnetick pieces of iron are attached. On the upper
part 32 spaces (which are commonly called _points_) are assigned to the
same number of mathematical intervals in the horizon or winds which are
distinguished by certain marks and by a lily indicating the north. The bowl
is suspended in the plane of the horizon in aequilibrium in a brass ring
which also is itself suspended transversely in another ring within a box
sufficiently wide with a leaden weight attached; hence it conforms to the
plane of the horizon even though the ship be tossed to and fro by the
waves. The iron works are either a pair with their ends united, or else a
single one of a nearly oval shape with projecting ends, which does its work
more certainly and more quickly. This is to be fitted to the cardboard
circle so that the centre of the circle may be in the middle of the
magnetick iron. But inasmuch as variation arises horizontally from the
point of the meridian which cuts the horizon at right angles, therefore on
account of the variation the makers in different regions and cities mark
out the mariners' compass in different ways, and also attach in different
ways the magnetick needles to the cardboard circle on which are placed the
32 divisions or points. Hence there are commonly in Europe 4 different
constructions and forms. First that of the States on the Mediterranean Sea,
Sicily, Genoa, and the Republick of Venice. In all these the needles are
attached under the rose or lily on the cardboard versorium, so that (where
there is no variation) they are directed to the true north and south
points. Wherefore the north part marked with the lily always shows exactly
the point of variation when the apex itself of the lily on the movable
circle, together with the ends of the magnetick wires attached below, rests
at the point of variation. Yet another is that of Dantzig, and throughout
the Baltic Sea, and the Belgian provinces; {166} in which the iron works
fixed below the circle diverge from the lily 1/4 of a rumbe to the east.
For navigation to Russia the dive