[ 4 *° 1 
ciety *. la the f th he compares the Two Obferva 
tions. In the 6 th and 7th, he mentions feveral c Par- 
heli't taken notice of by the Antients and Moderns ; 
and in the Sth enumerates the different Obfervables 
of this < Ph#nomenon i for the better inveftigating its 
Caufes. 
The gth gives the Opinions of feveral of the An- 
tients concerning the Prefages taken from Mock- 
Suns. 
Prom the 10th to the 1 ith inclufive, he relates 
clivers Manners of accounting for them, by the chief 
of the Antients and Moderns. 
In the 1 4 th, preparatory to his own Opinion, he lays 
down the DoQrine of the Rife of Vapours in fmall 
globular Bubbles of Air, with a watery Coat to each. 
In the 15 th, he refutes, by feveral Reafons and 
Experiments, Huygens's Manner of accounting for 
Haloes , which is by a vaft Number of very fmall 
Vapours, each with a fnowy Nucleus , coated round 
with a tranfparent Covering: And fays, that when 
the Sun depi&s its Image in the Atmofphere, and by 
the Force of its Rays puts the Vapours in Motion, 
and drives them towards the Surface, till they are 
collected in fuch a Quantity, and at fuch a Diftancc 
from the Sun on each Side, that its Rays are twice 
icfrattcd, and twice refle&ed, by the time they reach 
the Eye ; they exhibit the Appearance of a Halo , 
adorned with the Colours of the Rainbow : Which 
may happen in globular pellucid Vapours without 
fnowy Nuclei , as appears by the Experiment of hol- 
low glafs Spheres filled with Water. Therefore, 
whenever thofe fpherical Vapours arc fituated, as be- 
fore. 
* Philofopbical TrsnfatlioTis i N° 445. 
