MijceUanea Curio fa. aoi 



The (aflum'd) Sines of "| Water. Air. - 

 the Angles of Inci- piooooo : iooooo 

 deuce through — « ■ — j 

 The Sines of the corre-1 



fpondent Angles of ^134400. 100035 

 Emerfion out of * — • j 

 The Refra&ive Power? - 



of — — i— - If 344 35 



The Specifick Gravity"! 

 (if as 900 to 1 at the j 

 time of the Experi- f 34400 ... . C 38 



850 to 1) of- < J 



From hence it feems very probable that 

 their Refpe&ive Den fi ties and Refra&ive 

 Powers are in a juft Simple Proportion : And 

 if this mould be confirmed by fucceeding Ex- 

 periments, made at different Angles of Inci- 

 dence, and with Cylinders continuing ex- 

 haufted through feveral Changes of the Air, 

 it would be more than probable that the Re~ 

 fraftive Powers of the Atmofpbere are every 

 where, at all heights above the Earth, in pro- 

 portion to its Dcnfities and Expanfions. And 

 here it would be no difficult matter to trace 

 the Light through it, thereby to terminate 

 the Shadow of the Earth} and (together with 

 proper Expedients for meafuring the Quantity 

 of Light illuminating an Opaque Body) to ex- 

 amine at what diftances the Moon muft be 

 from the Earth to fufFer Eclipfes of the ob- 

 ferv'd Duration. This Limitation is tonfide- 

 rable enough in Aftronomy, abundantly to 

 recompenfe the Trouble of profecuting fuch 

 a new Experiment. 



ment) of or (if as 1 



A 



