The Panorama of Science

Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: HEAT. In taking a view of the magnificent theatre of nature, we at once perceive the vast importance of this agent: ? by its power, rocks, islands, hills, and mountains have been upraised out of the innermost depths of the earth;? by its operation, the genial moisture, which, under the form of rain, descends, cooling the heated air, and refreshing the parched tip soil, is raised from the bosom of rivers, lakes, and seas;?by its influence, the waters which were chained up by frost during the desolate reign of winter, are again set free to sparkle along at the bases of their sunny banks;?by its benignant agency, the trees, that were deprived of their foliage, and the herbs, that were apparently withered, are again invigorated with new life, and arrayed in new beauty;?it controls and modifies, indeed, life under every form; and is the most universally pervading and important agent with which we are acquainted. When we consider the dreary monotony of the polar regions, where human nature appears in its most humble and degraded form, and where the bears, wolves, and foxes seem alone to find appropriate habitations; and when we compare these trackless solitary wastes with the blooming valleys of sunny Italy, we at once see the vast influence of different temperatures on the surface of the globe; nor do we hesitate to refer such modifications to the sun, which is undoubtedly, the principal fountain both of heat and light. At a period when science was in its infancy, the ancients observed this general fact, and concluded that the sun was an immense globe of fire; but this opinion has long since been exploded. The astronomers of our own more enlightened age, have shown, by the aid of telescopes of vast power, that the sun is itself a solid and opaque body, perhaps a habitable globe...