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MicroGRaPpula. 
them:may fometimes make their Obfervations together, and that from 
divers Experiments we may be the better aflured of what certainty and 
exactnef§ fuch kind of ‘Obfervations are like to prove. And becaufe ma- 
ny of the Stars which may happen to come within the compals.of fich 
an Iconifm, or Map, may be fuch as are only vifible through a good Teh- 
Jeope, whole Pofitions perhaps have not been noted, nor their longitudes, 
or latitudes, any where remarked; therefore each Obfervator fhould in- 
deavour to infert fome fixt Star,whofe longitude, and latitude, is known 5 
or with his Te/e/cope he fhall find the Pofition of fome notable telefcopical 
Star, inferted in his Map, to fome known fixt Star, whofe place in the Zo- 
diack is well defin’d. aya 
Having by this means found the true diftance of the Moon, and ha- 
ving obferved well the apparent Diameter of it at that time with a good 
Telefcope; it is eafie enough, by one fingle Obfervation of the apparent 
Diameter of the Moon with a good Glaf, to determine her diffances 
in any other part of her-Orbit, or Dragon, and: confequently, {ome few 
Obfervations will tell us, whether fhe be mov’d in an El/ipfis, Cwhich, by 
the way, may alfo be found, even now, though think we are yet igno- 
rant of her true diftance)) and next ( which without fich Obfervati- 
ons, I think, we thall not be fure of ) we may know exactly the bignefs of 
thar E/4pfis, or Circle, and her true velocity in each part, and thereby be 
much ‘the better inabled to find out the true caufe of all her Motions. 
And though, even now alfo, we may, ‘by fuch Obfervations in one ftati- 
on, a5 here at Lowdox; obferve the apparent Diameter and motion of the 
Moon in her Dragon , and confequently be inabled to make a better 
ghefs at ‘the species or kind of Curve, in which fheis mov'd, that is, 
whether it be {pherical, or e//iptical, or neither, and with what propor- 
tional velocities fhe is carried in that Curve 3 yettill her true Parallax 
be knowii, we cannot determine either. | iG eae 
. Next, for the true diftance of the Sun, the beft way will be, by accu- 
rate Obfervations, madé in both thefe forementioned {tations, of fome 
convenient Eclipfe of the Sun, many of which may fo happen , as to be 
feen by both; for the Pexumbra of the Moon may, if the be fixty Semi- 
diameters diftant from the Earth, and the Sun above feven thoufand, ex- 
tend to about feventy degrees on the Earth , and confequently be feen 
by Obfervators as far diftant as London, and St. Helena, which are not 
full fixty nine degrees diftant. And this would much more accurately, 
then any way that has been yet ufed, determine the Parallax, and di- 
ftance, of the Sun; for asfor the Horizontal Parallax Ihave already 
fhewn it fufficiently uncertain 5 nor is the way of finding it by theEclipfe 
of the Moon any other then hypothetical ; and thet by the difference of 
the true and apparent quadrature of the Moon is lefs‘net uncertain, wit- 
nefS their Dedurttions from it,who have made ule of it 5 for Vendeline puts 
that difference to be but 4’. 30", whencé he deduces a vaft diftance of 
the Sun, asI have before fhewn. Ricciolo makes it full 30°. 00. but Re 
_ noldué,and Kircher, no lef then three degrees. And no wonder, for if 
We examine the Theory, we fhall find it fo complicated with uncertain- 
ties, | : Firft, 
