Page:The American Cyclopædia (1879) Volume XII.djvu/554

540 NUTATION NUTHATCH much from the thirty years' war, during which it witnessed the first contest between G-ustavus Adolphus and Wallenstein (1632), and lost its former commercial greatness ; but it has im- proved within the present century, and is now again famous for its industrial activity, par- ticularly in lead pencils, looking-glass plates, papier mache", machines, and ultramarine ; and it is the toy shop and one of the principal hop markets of Europe. An active trade is carried on with the United States, to which goods were exported in 1872-'3 valued at $2,737,560. NUTATION, in astronomy, a small periodic gyratory movement in the direction of the earth's axis, by which, if it existed independent of the motion in precession, the pole of the earth would describe in the heavens a minute ellipse. This ellipse would cover a space by its longer axis of 18'5", and by its shorter of 13'7", the longer axis being directed toward the pole of the ecliptic. The nutation period is a little less than 19 years (18-6), and cor- responds to that of a revolution of the moon's nodes, with which it is directly connected. The effect of the nutation on the position of the stars is combined with the effect from precession ; and as both are referable to the same physical agency for explanation, their further consideration will be found in the article PEECESSION. NUTCRACKER, a conirostral bird of the crow family, and genus nucifraga (Briss.). The bill is longer than the head, strong, with cul- men elevated and sloping to the entire tip ; the lateral margins straight ; gonys very long and ascending ; the nostrils basal, covered by frontal bristles; wings long and rounded, with the fourth and fifth quills longest ; tail moderate, rounded on the sides; tarsi longer than middle toe, covered in front with broad scales ; toes long, robust, and strongly scutel- lated ; claws long, sharp, and curved. The Nutcracker (Nucifraga caryocatactes). common nutcracker (JV. caryocatactes, Briss.), the best known species, is about 13 in. long, and the bill If ; it is about the size and shape of the European jay; the bill and feet are brownish black; the general color dull red- dish brown, blackish brown above ; the whole plumage, except the top of the head and the upper tail coverts, is marked with oblong white dashes margined with dark brown at the end, largest on the lower parts ; lower tail coverts and tips of tail feathers white. This bird, rare in Great Britain, is common in the woods of the mountainous parts of Europe and Asia, especially in Switzerland, and in Russia ; they are usually seen in pairs, but sometimes in flocks, migrating according to the season in search of larvae and insects, which they obtain from trees in the manner of woodpeckers ; they are also fond of the seed of fir trees, and of nuts, which they break by repeated strokes of the bill ; they are said to devour small birds and eggs. The nest is made in a hole in a de- cayed tree ; the eggs, five or six, are yellowish gray with a few spots of light brown. This bold and familiar bird by its nearly straight bill seems to form a transition from the crows to the starlings, and in some respects to the woodpeckers, the last of which it also resem- bles in some of its habits. NUTGALL. See GALLS. NUTHATCH, a subfamily of tenuirostral birds of the creeper family, scattered over North America, Europe, and India and its archi- pelago. In the typical genus sitta (Linn.) the bill is entire, about as long as the head, slender, compressed, straight, and sharp-pointed, with the gonys long and ascending; nostrils in a groove, covered by bristles directed forward ; wings long and acute, reaching nearly to end of tail, the first quill being very short, and the third and fourth about equal and longest ; tail short, broad, and nearly even ; tarsi about equal to middle toe, strong and scutellated; toes long, the outer much longer than the in- ner, the hind toe the longest, and all armed with sharp and curved claws. Nearly 20 spe- cies are described. They prefer dense woods, where they run rapidly up and down the trunks and branches of trees in spiral circles, examining the crevices in the bark for spiders and insects; in winter they approach houses, and feed upon seeds, grains, nuts, and other vegetable food. The largest of the American species is the white-bellied nuthatch {8. Caro- linensis, Gmel.), about 6 in. long, with an ex- tent of wings of 11, and the bill along the gape five sixths of an inch ; the bill is black, and iris dark brown ; general color above ashy blue, with top of head and neck black ; under parts and sides of head to above the eyes white ; under tail coverts and tibial feathers brown ; concealed primaries white. This is a bold, active, and familiar bird, though gener- ally living in retired woods ; the nest is made in the hole of a decayed tree; the eggs, five or six, are dull white, spotted with brown at the larger end; the flight is rapid, and at times protracted ; like others of the family, they are fond of roosting head downward. This species is spread over eastern North