HALLOW EVE HALO 405 Hallowell is at the head of ocean steamboat navigation, and the wharves are accessible by vessels of 9 ft. draught. Excellent granite is obtained in the neighborhood. It con- tains a cotton mill, two iron founderies, sev- eral granite works, marble works, three tan- ning and currying establishments, and manufac- tories of boots and shoes, bricks, cabinet ware, dies, carriages, floor oil cloth, lumber, ma- inery, putty and whiting, soap and potash, inks, &c. There are two halls, including the y hall, a hotel, two national banks, a sa- js bank, a classical school, 13 public schools iluding a high school), a free library of 000 volumes, and six churches. Hallowell as permanently settled soon after the erection Fort Western in 1754 on the site of the pres- t city, although a few traders or colonists re- .ed there a century earlier. It was incor- >rated as a town in 1771, at which time it in- .ed Augusta v Chelsea, the greater part of Chester, and a portion of Farmingdale and iner. A city charter was adopted in 1 852. HALLOW EVE, Hallowmas Eve, or in Scotland illoween, the vigil of All Hallows or All Saints' ,y, Oct. 31. It has always been the occasion certain popular usages in Christian coun- .es, such as the performance of spells by ung people to discover their future partners br life, and certain fireside revelries, as crack- ing nuts and ducking for apples. Hallow- een is thought to be a night when witches, devils, and other mischief-making beings are all abroad on their baneful midnight errands ; particularly the fairies are said on that night to hold a grand anniversary. Burns's poem "Halloween" describes the superstitious cus- toms and beliefs of the Scottish peasantry con- cerning this festival. (See ALL SAINTS' DAY.) HALO (Gr. aAwf, a threshing floor, originally f a round shape), a term commonly used in eteorology to include all those phenomena in hich a luminous ring, either colored or un- 'lored, is seen around the disk of the sun or on. There are two distinct classes of such enomena, called coronas and halos, and it is y for convenience that the latter term is iietimes used to include them all. Here we shall consider them under their several heads. The meteorologist Kaemtz includes under the term coronas all cases in which, when the sky is covered with light clouds, colored circles are seen surrounding the sun or moon; also when a glory is seen around the observer's shadow on a cloud. Under the head " halos properly so called," he includes the great circles which sur- round the sun or moon, the diameter of which amounts to about 44. The attendants of ha- los are : 1, circles having a double diameter ; 2, parhelia or mock suns ; and 3, various other circles. Coronse are distinguished from halos in this fundamental respect, that the former are* due to particles or vesicles of water in mist or cloud, the latter to minute crystals of ice. Corona. All clouds which are not too dense to prevent the light of the sun or moon from passing through, produce coronas of greater or less intensity and regularity. When the clouds are irregular in outline, the coronas are incomplete. When the corona is complete, the following arrangement of colors can be recognized. Close by the sun a dark blue cir- cle can be perceived, next a white circle, and then a red; outside the series there can be seen under favorable conditions a second se- ries, consisting of colored circles in the follow- ing order, proceeding eastward from the sun : purple, blue, green, pale yellow, and red. " More frequently," says Kaemtz, *' we observe near the sun blue mingled with white, then a red circle clearly limited within, but confused outside with the others. If a second red cir- cle exists outside this, then green is observed in the interval by which they are separated. The distance of this circle from the centre of the sun varies according to the state of the clouds and the atmosphere ; I have found it from 1 to 4." The rings of coronas, the colors of which are those of the reflected se- ries in thin plates, are fringes due to interfe- rence of rays which have undergone diffraction by grazing on either side of numerous minute globules of cloud or fog, that have for the time nearly the same size. An illustrative in- stance was first given by Necker of Geneva. When the sun rises behind a hill covered with trees or brushwood, a spectator in the shadow of the hill sees all the small branches that are nearly in the line of the solar rays, on either side, projected on the sky, not black and opaque, but white and brilliant, as if of silver ; the effect of a small opaque body on the light being, in this class of cases, equivalent to that of a small opening in a dark body through which the rays should penetrate. Coronas ex- ist around the sun more frequently than would be supposed ; but they are often not observed, on account of the brilliancy of that orb. At such times they may be detected by looking at the reflection of the sun in still water, or in black glass. Anthelia. When the sun is near the horizon, and the shadow of the ob- server falls on any surface covered with dew, there can be perceived a glory especially round the head of the shadow. Anthelia are also seen, and more perfectly, when the observer's shadow falls on or near clouds that lie opposite the sun; or in polar regions when the shadow is cast horizontally upon a fog. Bouguer was the first to observe the phenomenon. He no- ticed that the shadow of his head, on clouds among the Andes, was encircled by three col- ored rings having diameters of 5f-, 11, and 17. Scoresby, who observed the phenomenon in polar regions, saw four concentric circles round the shadow of his head: the first was white, yellow, red, and purple, and had a semi- diameter of 1 45' ; the second was blue, green, yellow, red, and purple, and had a semi-diam- eter of 4 45' ; the third was green, whitish, yellowish, red, and purple, and had a semi-di- ameter of 6 30' ; the fourth was greenish,
