These needle-like columnar formations, which are excellently portrayed in the illustrations, are often found from two to six inches in height, and are formed from the moisture which rises from the warm soil and freezes. These columnar crystals do not form in this manner in the extremely cold weather, or after the ground has become solidly frozen to a certain depth; therefore they may be classed among the hoar-frost formations of early autumn. As shown in detail in the photographs, the formation of each section of this type of hoar-frost crystal appears as a prism-like columnar growth, the base of the prism being hexagonal in shape, and closely resembling an unset jewel. Through the still, cool nights in autumn the Hoar-frost Fairy works steadily, covering vegetation with glittering frost-work, touching all unsightly places, decaying woods, old gray fence-rails lightly in passing, and upon the following morning, if you are fortunately stirring before the sun ruins the best work of the hoar frost, you will discover many wonderful works of art. Sometimes it will be a miniature, scintillating forest of needle-like crystals attaching itself to some old rail. Again a perfectly marvellous collection which you may find deposited upon a board; tiny tabular ice crystals of hoar frost closely resembling a flight of white butterflies or moths powdered over its flat surface. We were fortunately able to secure one of this type; and with the aid of a small pocket microscope, you may be able to discover this pleasing variety, as shown in our photograph. The same variety of hoar frost was again encountered, where the delicate crystals had formed and grouped themselves upon a stick or straw; this is wonderfully suggestive of a group of butterflies resting upon a flower-stalk, as we frequently observe them in mid-summer, where flights of the yellow wayside butterflies assemble upon a mullein-stalk in precisely the same fashion. [Illustration: 37. An exquisite lace pattern in frost] The showy illustration resembling in formation a branch of bleached coral, is another interesting example of the hoar frost’s eccentric development, and was found clinging to a decaying beam, under an old building. The beautiful feathery spray, somewhat resembling a miniature fir tree, was taken from the branch of a tree, about which it had formed, and is made up of countless, lace-like, filmy ice prisms, of infinite delicacy. Much is lost in the scintillating iridescence of these frail hoar-frost crystals when seen merely in the photographs, for they frequently show rare colour effects when seen in the open.