(13 ) 
the Ccpemica^ Syftem againft the Ptolemaic and Tychonic. Yet, 
likea rigid Philofopher, not being fully fatisfied with thefe 
Obfervations, he declares his extraordinary defire to have 
made others with more accuratenefs, than, by reafon of in con- 
venient weather and want of health, he was able to make 
thofe. However, he thinks he harh given fiifficient cccafion 
and direffion toothers to profecute this noble undertaking. 
At the end of the explication whereof he mentions fome things, 
which he looks upon as very remarkable , occurring in thofe 
Obfervations ; one of which was , that in theday time,theSun 
fliining very clear, heobferved the bright Star in the Dragons 
head to p^fsby thtZep^ith asdiftinflly and clearly as if the 
Sun had been fet ; which heefieems ro have been the firft time 
that the Fixt Stars were feen when the Sunlliined very bright 
without any obfcuripg of its light by Eclipfe or otherwife; 
that Tradition, of feeing the Stars in the day with the naked 
Eye out of a deep Well or Mine, being by him Judged a meer 
fiftion, the thing being thought by him impoffible. 
' Laft ofall, he promlfes, that he will explain to the Curl- 
.ous a Syftem of the World differing in many particulars from 
any yet known, but anfwering in all things to the common ru'es 
of Mechanical Motions ; which Syftem he . here declares to de- 
pend on three Suppofitions *. i . That all Celeftial bodies wbat- 
foeverhavean Attraction or Gravitating power towards r.heir 
own Centers, whereby theyattraft not only their o\v 
and keep them from flying from them fas we may obfervc 
Earth to do ; )buc alfo all other Celeftial bodies chat are with 
in theSphereof theiradivity. 2. That all Bodies whatfoe- 
ver,that are put into a direfl and fimple motion ^ will fo conti- 
nue to move forward in ^ Streight I'me, till they are by fome 
other more effeftnal pow^r defled^ed and bent into a motion that 
defcribes fome Curve Vme. 3. That thefe Attraftive powers 
are fo much the more powerful in operating, by how much the 
nearer the body , wrought upon, is to their own Cen- 
ten. ' ' 
IL M E- 
