70 
LUMINOUS PHENOMENA. 
Paraselene. 
Iris or Rain- 
bow. 
Double Rain- 
bow. 
Colonrloss 
Rainbow. 
these plirenmnena vary too much to be particularly described 
here : their peculiarities ought to be minutely observed, and 
noted down in a Meteorological Journal. ' 
Paraselene. Lunce imago falsa, vcl plures imagines huias 
generis circa Lunam disposiics, ei magis minusve Halonibits, 
aliisque lucidis vlttis comitatce. 
Ohser. The paraselene, the parhelion, and the several kinds 
of halo and corona, all appear to result from the intervention of 
cloud between the spectator and the sun or moon, through 
which the light passes ; but there is another well-known phe- 
nomenon, which always appears in a cloud opposite to the sun 
or moon ; namely, the 
Iris. Def. Circulus maximus coloratus in Nube Soli opposild 
visas, et cuius centrum centra Solis oppositum est, qui, qudd' | 
portio eius tanlum videtur, arcus adparet. 
Olser. The rainbow is an appearance too familiar to every 
one to need any particular description. As the halo and corona 
appear generally in the cirrostratus cloud j so the Iris appears 
always in the nimbus. Lunar rainbows are Very rare occurrences. 
Iris duflex. Def. Duo Circuli colororati quorum centrum 
commune Solis centra opponitur qui quod eorum portiones 
tantum videantur Arcus adpareant. 
Double rainbows are not unfrequent. The order of colours 
in the outer one is reversed,* They are mentioned by Aratus.f 
Iris vnicolor. Circulus maximus colorum txsors, in nube | 
visas, et cujus centrum centra Solis vel Lunae opponitur ; qui I 
quod portio (jus tantum videatur Arcus adpareat, \ 
The Iris unicolor is more properly a colourless rainbow, and ' 
• Arist. Meteor, lib. iii. cap. 5. 
t Aral. ‘JOS. I 
V I 
appears h 
