474 THE FARMER AT HOME. 



is divided into several sorts, according to their respective proportions. 

 Thus, three parts of copper and one of zinc, constitute brass ; five or 

 six of the former, and one of the latter, afford pinchbeck. Zinc is 

 found in England, Hungary, and some other parts of the globe. 



ZODIAC. The zodiac is an imaginary belt round the heavens, 

 among the fixed stars, sixteen degrees wide, the centre of which is the 

 plane of the ecliptic. In this space or belt all the primary planets 

 revolve round the sun, with the exception of Juno, Pallas, and Ceres, 

 three of the asteroids. The ecliptic, and consequently the zodiac, has 

 been divided into twelve equal parts, consisting of thirty degrees each, 

 called signs. As one-half of the ecliptic is situated north of the equa- 

 tor, and the other half south of it, no six of these signs are in the 

 north equatorial hemisphere, and the other six in the southern hemi- 

 sphere. 



ZOOLOGY. Few departments of knowledge are more interest- 

 ing than the natural history of animals, and the attention given to it 

 in the present age, furnishes the best evidence that its claims to notice 

 begin to be fully estimated. In our own country the inducements to 

 its cultivation are peculiarly strong, for our immense lakes, forests, and 

 mountains have as yet been but imperfectly explored by naturalists, 

 and the little that is known of their productions leads to the belief 

 that they contain abundance to encourage and reward the labors of 

 science. The study of zoology is .particularly advantageous to the 

 young, from its direct tendency to cultivate one of the most useful 

 habits of the mind, that of attentive observation of things of common 

 and daily occurrence. Its objects are everywhere around us swim- 

 ming in the waters, flying in the air, walking the earth, and burrow- 

 ing beneath it. One set provides our food and clothing, another 

 purloins and destroys them. Some attack, and others protect us. 

 Their forms are continually before our eyes, and their voices always 

 sounding in our ears. 



In order to treat clearly of the animal kingdom, it is necessary to 

 consider it according to some method of arrangement, by which those 

 animals which most resemble one another are connected together for 

 the convenience of description. This arrangement is founded upon 

 their form and structure, and separates them into various divisions 

 and subdivisions, according to their degree of similarity, and the 

 points in which their structures correspond. Such a system of arrange- 

 ment is called a classification of the animal kingdom ; and an accu- 

 rate acquaintance with the principles on which it is founded will be 

 of great assistance to the student of natural history. 



All animals are divided in the first place into two grand divisions, 

 namely, into vertebral, embracing those that have a spine, or verte- 

 bres, and into in vertebral, comprehending all those that are destitute 

 of a spine, or vertebral column. The vertebral animals are subdi- 

 vided into four classes, and the in vertebral into five. Each of the 



