ZONE, in geography and astronomy, a division of the terraqueous globe with respect to the different degrees of heat found in the different parts thereof.
A zone is the fifth part of the surface of the earth, contained between two parallels.
The zones are denominated torrid, frigid, and temperate.
The torrid zone is a fascia, or band, surrounding the terraqueous globe, and terminated by the two tropics. Its breadth is 46. 58. The equator, running through the middle of it, divides it into two equal parts, each containing 23. 29. The ancients imagined the torrid zone uninhabitable.
The temperate zones are two fasciae, or bands, environing the globe, and contained between the tropics and the polar circles. The breadth of each is 43. 2.
The frigid zones are segments of the surface of the earth, terminated, one by the antarctic, and the other by the arctic circle. The breadth of each is 46. 58.
Mammalia. IS that part of Natural History which relates to Animals. It is necessary to mention in this place, that we have given the descriptions and characters of animals under their proper names. The scientific part of the subject, therefore, or the method of investigating the genera or species of animals, by means of natural or artificial arrangement, only remains to be explained.
In order to abridge the study of zoology, many methods of reducing animals to classes, genera, and species, have been invented. But as that of Linnaeus is undoubtedly the best, the most extensive, and the most generally adopted, we shall give a brief account of it.
Linnaeus divides the whole animal kingdom into six classes. The characters of these six classes are taken from the internal structure of animals, in the following manner: