S24 Washington Sirmst, Boston 8, Mass. 



(Ulntered at the Poat Offloe, Boston, Mats., 

 OS Second Class Mail Matter) 



DOUBLE HAIOS, 

 VERY RARE, SEEN 

 IN SKY TODAY 



Described as "Rainbows," the Phe- 

 nomenon Attracts Many by Colors 

 and Brilliant "Sun Dogs" 



At the time of year when ancient prints 

 of the birth o£ Christ bring celestial halos 

 to the pubiic mind, Boston, this morning, 

 was given an opportunity to study a rare 

 solar phenomenon, 90 per cent 'perfect— not 

 I "aouhle rainbows'" as 'they were described, 

 by those who observed the brilliant spec- 

 tacle— but -double halos^' of the meteorolo- 

 gist, illuminating, the sky, 



Shortlv before the sun can^^e up a shaft 

 of light preceded Us arrival. Then cama a 

 I luminous cross formed by two shafts of 

 I light and then two complete circles, one 

 I within the other, an inverted circular tan- 

 I gent on the outer circle, dazzling in the 

 i brilliance of the colors of the spectrum at 

 ' point of contact, and three parhelia, or 

 a dogs." on each side of and above the 

 „„... These "lialos" were circles around 

 the sun, caused by the refraction and re- 

 flection of light through prismatic ice par- 

 ticles. By refraction the light was broken 

 prismatic colors and by reflection the 

 phenomenon was carried to the eye. 



Tills morning was a perfect one for thf 

 display, according to meteorologists 

 Marls T. Nesmlth and Hathaway of 

 the Weather Bureau, who observea 

 and recorded the occurrence here. Lofty 

 cirrus clouds and others formed at 

 temperatures considerably below 0° Centi- 

 grade usually consist of small but 

 relatively thick snowflakes with flat base.s 

 or ice spicules, with flat or, rarely, pyra- 

 midal bases, always hexagonal in pattern 

 and detail. Tliese miniature prisms bring 

 a,bout the peculiar oocular phenomenon. 

 Rainbows, on the other hand, are produced 

 by a complicated process of refraction oC 

 sunlight as it enters and passes out of the 

 raindrops, internal reflection of the iiglit 

 within the drops, and interference of the 

 rays after leaving the drops. 



In addition to the most frequent of thi 

 numerous phenomena caused by the pas- 

 sage of light through ice crystals of which 

 the more common halo of 22° is an example 

 (occasioned by the prismatic refraction 

 ■between the sides of the hexagonal spicules 

 forming angles of 60° with each other) 

 there was the halo of 46°, caused by the 

 1 refraction between the sides and bases of 

 the spicules, forming angles of 90° with 

 each other. - i 



t the 



As the great, or parhellc circle of light 

 bisected the sun, there became noticable 

 the colored bright spots like the sun itself, 

 known as parhelia or "sun does," one to 

 the right and one to the left. Each bright 

 spot was in the direction of maxlmun' 

 light or minimum refraction and had the 

 ime altitude as the sun. Later, a thiril 

 m dog appeared above the sun. Over all 

 as the tangential arc on the outer halo 

 ith its bright colors, gome observers re- 

 ported fragmental arcs, 'concave toward the 



When the reflecting edges of the ice crys- 

 tals are vertical, according to the ( 

 tlon of instructions to (he observe--; 

 weather bureau, as they tend to be i.. 

 case of relatively thin snowflakes fallmg 

 throug'h still air, parhelia are produced. 

 In general, these edges lie in all 'Ji'-eetions 

 especially at the windy cirrus level and 

 .hen the crystals are of the short columnar 

 type; and as refracted light reaches an ob- 

 server in every plane through his eye and 

 the sun to which the refracting edges are 

 approximately normal, it follows that he 

 effect produced by the 



be more or less symmetrically 11=^^^*"'/^^ 



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 r^::r'iLt::dir^er?:^^:i:i:3 



---f^n^^f ^:s-r°rr:^,t:cr 



fS- of UiaLolorisleast^fj^cted^ O^her 



colors follow, witn uici .a^e °« ^..^ 



the -S^lf^^X^'^'n.Hr the" fkde so ra, 

 decrease of v.b.\p. lei „ui j oeldo' 

 idlv that green is indist.r.ct and blue seldo, 



""xwe'nt^'iwo degrees was the low reading 



finds becoming southerly Thursday. The 

 X mum' temperature tonight will be near 

 twenty degrees." Sixteen b-'^^ z^ro wa 

 ildest this morning, at White R ve 

 Northfleld, Vt., reported eight abov 



the 



1 Ont. 



'"■The area of low pressure has moved 

 eastward from the Atlantic coast and in- 

 creased in energy. The center this morn- 

 ing was east of the limits of the map. 

 Light rain or snow has fallen in the Mis- 

 sissippi Valley from Tennessee northward 

 and in the districts eastward. The .area of 

 high pressure has moved southeastward to 

 the Gulf States. Killing frosts have oc- 

 curred along the Gulf coast. The north- 

 western area of low pressure has moved to 

 the Dakotas and Minnesota, but the bar- 

 ometer is still moderately high north of 

 Minnesota. Rain has fallen on the North 

 Paciflo coast. 



