NUTATION 



4314 



NUTMEG 



NUTATION, nuta'shun, an astronomical 

 term, used to define a subordinate motion of 

 the earth's axis, caused by the unequal attrac- 

 tion of the moon on the equatorial ring of the 

 earth. The sun and the moon each exert an 

 attraction, unequal in force, on the earth's sur- 

 face. The result is to give to the earth two 

 separate motions, one called precession, the 

 other nutation. The greater the distance of 

 the sun and the moon from the plane of the 

 equator the greater is the change in the earth's 

 motion. Gravitation, or attraction, has the 

 effect of changing the relative position of the 

 il equator, causing the celestial pole to 

 describe a circle round the pole of the ecliptic 

 once in 25,800 years. This rotation is subject to 

 slight variations or vibrations, called nutation. 



NUT 'CRACKER, a bird of the crow family, 

 found in the mountainous pine regions of Eu- 

 rope and Asia, and so called because of its 

 supposed ability to crack nuts with its bill. It 

 is a small bird with a comparatively-long tail; 



NUTCRACKER 

 its plumage is a mixture of light brown, wjiite 

 and black. The nutcracker feeds chiefly on the 

 seeds of pine cones, and has the rather inter- 

 esting habit of holding these in its claws while 

 pecking at them. The American nutcracker is 

 called Clarke's crow. The speckled, grayish- 

 green eggs of this bird are laid m a nest hidden 

 in the top of a tall pine tree. 



NUT 'HATCH, the name of a group of climb- 

 ing birds, common throughout the temperate 



THE NUTHATCH 



regions of North America and Europe. Nut- 

 hatches ivcnvr their name from their habit 

 of wi -lining nuts into crevices in the bark of 

 trees and then 

 "hatching" them 

 with repeated 

 strokes of the 

 bill. The best 

 known American 

 species is the 

 white - breasted 

 nuthatch, a bird 

 about six inches 

 long. As its name 

 indicates, the un- 

 der parts are 

 white; above, the 

 bird is bluish-ash, 

 with black, blue 

 and white wings 

 and black neck. 

 These nuthatches 

 are shy in sum- 

 mer and keep to the deep woods, but in winter 

 they are commonly seen about houses and 

 orchards, where food is likely to be found. 

 They feed chiefly on insects. In climbing, they 

 do not move upward, braced by their tails, as 

 do other climbers, but zigzag in every direction, 

 often head downward. They have a peculiar 

 wavering flight, which helps them to evade 

 birds of prey. They build their nests in holes 

 in trees or stumps. The eggs are from four to 

 eight in number and are white or creamy in 

 color, speckled with reddish-brown or lavender. 

 Other prominent American species are the red- 

 breasted and brown-headed nuthatches, both of 

 which are smaller than the white-breasted. 



NUT 'MEG, the kernel of a tropical fruit, 

 which is extensively used as a spice. When 

 ripe the fruit looks like a golden-yellow pear 

 hanging among shiny, gray-green leaves; the 

 nutmeg tree grows from twenty to thirty feet 

 in height and is a bushy evergreen. Although 

 the trees originally grew in the Spice Islands, 

 they have been successfully cultivated in all of 

 the East Indies, the West Indies, Brazil, Ceylon 

 and India. Their long, pointed leaves have 

 well-marked veins, while the pale yellow flowers 

 hang in drooping clusters, much resembling 

 lilies of the valley. As the fruit ripens, the 

 fleshy part becomes rather hard, somewhat like 

 candied fruit, and finally splits open at the top, 

 disclosing a bright scarlet membrane, which 

 partly covers the nut. From this membrane is 

 obtained the spice called mace (which see), 



