& 6 MiJceUanea Curiofa. 



thought fit to give it the Title of Thdumantis, 

 or the Child of Wonder ; and placing it in the 

 Number of the Goddejfes, attributed to it the 

 Office of a Mefcnger between the Cceleftials 

 and mortal Men \ which Fable, perhaps, qwes 

 its Original to Gene fis, Ch.9. V. 13. 



Thofe that attentively confider'd the Phe- 

 nomena of the Rainbow, always found, that 

 the Sun's Rays reflected by a Watery Cloud, 

 came to the Eye under a certain Angle ; from 

 whence arofe theArcb, or Circular Figure of 

 it. But as for the Caufe and Reafon of the 

 Colours, as alfo of the Magnitude of the 

 Angle, by which we conftantly find it diftant 

 from the Point oppoflte to the Sun \ thefe were 

 Things, that a long while, and very greatly 

 p&rlex'd, as well the Moderns, as Ancients. 

 Neither did they do any thing to the Purpofe 

 herein, till the Famous Monfieur Des Cartel 

 making ufe of the Mathematical Sciences, 

 Ihew'd by feverai Examples, that more ftrift 

 and clofe Methods of Reafoning might and 

 ought to obtain, even in our Management of 

 thofe Phyftcal Speculations. Amongft other 

 things (tho' it mult be own'd that herein he 

 had Ibme Light, from the Learned Antonio de 

 Domini*, Arch-bifhop of Spalato) he explain'd 

 the Theory of the Rainbow. And having dif- 

 cover'd the Laws of Refradtion, he clearly de- 

 monftrated ? that the Primary Iris was nothing 

 elfe, but the Sun's Image reflexed from the 

 Concave Surface of innumerable Spherical 

 Drops of Rain and that with this Condition, 

 that thofe Rays that were parallel at their 

 Incidence, were not loft or diflipated by the 

 Reflexion, and the Two Kefratlions (one at the 



