d more exact will their Observations be,
though they are somewhat the more difficultly manag'd. These should be
fitted with a _Rete_, or divided Scale, plac'd at such a distance within
the Eye-glass, that they may be distinctly seen, which should be the
measures of minutes and seconds; by this Instrument each Observator should,
at certain prefixt times, observe the Moon, or other Planet, in, or very
near, the Meridian; and because it may be very difficult to find two
convenient stations that will happen to be just under the same Meridian,
they shall, each of them, observe the way of the Planet, both for an hour
before, and an hour after, it arrive at the Meridian; and by a line, or
stroke, amongst the small fixed Stars, they shall denote out the way that
each of them observ'd the Center of the Planet to be mov'd in for those two
hours: These Observations each of them shall repeat for many dayes
together, that both it may happen, that both of them may sometimes make
their Observations together, and that from divers Experiments we may be the
better assured of what certainty and exactness such kind of Observations
are like to prove. And because many of the Stars which may happen to come
within the compass of such an _Iconism_, or Map, may be such as are only
visible through a good _Telescope_, whose Positions perhaps have not been
noted, nor their longitudes, or latitudes, any where remarked; therefore
each Observator should indeavour to insert some fixt Star, whose longitude,
and latitude, is known; or with his _Telescope_ he shall find the Position
of some notable _telescopical_ Star, inserted in his Map, to some known
fixt Star, whose place in the _Zodiack_ is well defin'd.

Having by this means found the true distance of the Moon, and having
observed well the _apparent Diameter_ of it at that time with a good
_Telescope_, it is easie enough, by one single Observation of the apparent
Diameter of the Moon with a good Glass, to determine her distances in any
other part of her _Orbit_, or _Dragon_, and consequently, some few
Observations will tell us, whether she be mov'd in an _Ellipsis_, (which,
by the way, may also be found, even now, though I think we are yet ignorant
of her true distance) and next (which without such Observations, I think,
we shall not be sure of) we may know exactly the bigness of that
_Ellipsis_, or Circle, and her true velocity in each part, and thereby be
much the better inabled to find out the true