Anthropology has reached that point of development where the careful investigation of facts shakes our firm belief in the far-reaching theories that have been built up. The complexity of each phenomenon dawns on our minds, and makes us desirous of proceeding more cautiously. Heretofore we have seen the features common to all human thought. Now we begin to see their differences. We recognize that these are no less important than their similarities, and the value of detailed studies becomes apparent. Our aim has not changed, but our method must change. We are still searching for the laws that govern the growth of human culture, of human thought; but we recognize the fact that before we seek for what is common to all culture, we must analyze each culture by careful and exact methods, as the geologist analyzes the succession and order of deposits, as the biologist examines the forms of living matter. We see that the growth of human culture manifests itself in the growth of each special culture. Thus we have come to understand that before we can build up the theory of the growth of all human culture, we must know the growth of cultures that we find here and there among the most primitive tribes of the Arctic, of the deserts of Australia, and of the impenetrable forests of South America; and the progress of the civilization of antiquity and of our own times. We must, so far as we can, reconstruct the actual history of mankind, before we can hope to discover the laws underlying that history.

The great Appalachian Mountains, which run from York River back of these Colonies to the Bay of Mexico, show in many Places near the highest Parts of them, Strata of Sea Shells, in some Places the Marks of them are in the solid Rocks. 'Tis certainly the Wreck of a World we live on!

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Such changes in the superficial parts of the globe seemed to me unlikely to happen, if the earth were solid to the centre. I therefore imagined, that the internal parts might be a fluid more dense, and of greater specific gravity than any of the solids we are acquainted with, which therefore might swim in or upon that fluid. Thus the surface of the globe would be a shell, capable of being broken and disordered by the violent movements of the fluid on which it rested.

It must be for truth's sake, and not for the sake of its usefulness to humanity, that the scientific man studies Nature. The application of science to the useful arts requires other abilities, other qualities, other tools than his; and therefore I say that the man of science who follows his studies into their practical application is false to his calling. The practical man stands ever ready to take up the work where the scientific man leaves it, and adapt it to the material wants and uses of daily life.

Branches or types are characterized by the plan of their structure,
Classes, by the manner in which that plan is executed, as far as ways and means are concerned,
Orders, by the degrees of complication of that structure,
Families, by their form, as far as determined by structure,
Genera, by the details of the execution in special parts, and
Species, by the relations of individuals to one another and to the world in which they live, as well as by the proportions of their parts, their ornamentation, etc.

Study nature to find your voice. One reason the natural history genre thrives today is the tremendous variety of voices it makes possible: the wild exactness of Annie Dillard, the calm thankfulness of Terry Tempest Williams, the scientific precision of Bernd Heinrich. But again, this is not just the province of professional writers or exceptional talents. No matter how dry or literal an amateur naturalist’s field notebook might be, sooner or later it begins to fill up with descriptions of her experience; also her theories and suppositions, her value judgments, her wild flights of fancy. She can push this further, if she wants to. Like describing nature itself, attempts to capture our own experience, interpret what we are seeing scientifically, clarify our value judgments or create new imaginative worlds, are endlessly fascinating. One gets better at them as one goes along.

On an outcrop of volcanic bedrock near the paath sit half a dozen erratic boulders, some weighining as much as twenty tons, of a coarse-grainned pink granite. Once, I chipped off a sample of)f the rock and followed the bedrock scratches northth, looking for the source. Like an Indian trail of bent twigs. le scratches led me several miles out of Easton into the town of Stoughton, where I found what I was looking for, a south-facing ledge of bedrock that under the hand magnifier was identical to the erratics. It is well known that glaciers "pluck" boulders from the downstream side of the rocky outcrops they move across (all of New England's ragged ledges are on the south sides of hills), so I was sure I had found my source. And that's where I stopped. But the trail goes on. The scratches lead orth from Stoughton, through the western suburbs of Boston, up the valley of the Merrimack River, veering slightly westward near Concord, New Hampshire, toward the Connecticut River, where they pass into Vermont, and on into Canada.

It is possible to find bits of glacial drift in Easton that had their origin anywhere along the line of scratches. Pieces of New Hampshire, Vermont, and Quebec litter the ground beneath my feet. The trail of scratched rock leads south, too, out of Easton, ^ through Wareham, under Buzzards Bay and Vineyard Sound (which, of course, were not submerged when so much water lay frozen upon the land), to Martha's Vineyard, the southern terminus of the glacier, where even today one might find a scrap of our North Easton bedrock carried there by moving ice.

What gravity is and why it is, no one knows. Albert Einstein spent most of his life trying to figure it out, but the secret eluded him. it is simply a fact that everything in the universe with mass pulls on everything else. If it weren't for the initial outward impetus of the Big Bang, gravity would have caused the entire universe to collapse into a heap. (Indeed, someday the cosmic collapse may happen, if and when the initial impetus is expended, although the best evidence suggests that the expansion will go on forever.) According to present theories, the universe began about 15 billion years ago as an explosion from an infinitely small, infinitely hot seed of pure energy As the primeval fireball expanded and o. cooled, matter—hydrogen and helium—condensed from radiation. The first stars and galaxies were born as gravity pulled the hydrogen and helium gas together into massive spheres and eddies. As stars burn, they fuse hydrogen nuclei into helium and then into heavier elements, and when stars die explosively, they scatter those heavy elements into space. After many generations of exploding stars had seeded the universe with carbon, oxygen, silicon, and iron, our own Earth and Sun were squeezed into existence by gravity.

When atomic nuclei fuse at the core of a star, some of their mass is turned into pure energy, according to Einstein's famous equation, E = mc^2 (energy equals mass times the speed of light squared). Every second at the Sun's center, 660 million tons of hydrogen are fused into 655 million tons of helium, and the missing 5 million tons of matter ultimately appears at the Sun's surface as heat and light radiated into space. A tiny fraction of the Sun's energy falls upon the Earth's oceans and evaporates water molecules into the air. It takes about 1,000 calories of energy for the Sun to evaporate a thimbleful of water from the sea; each thimbleful of water in the atmosphere represents 1,000 calories of stored solar energy. The Sun does the heavy lifting on Earth, heaving tens of thousands of cubic miles of water up out of the seas and into the atmosphere each year. Most of this water precipitates back into the oceans, but some of it falls on land as rain or snow, from whence it makes its way downhill to the sea in a great recirculation called the water cycle. Around and around the water has cycled for 4 billion years. since the oceans were born, in trickle or torrent, eroding and shaping the land, bringing fresh water to land plants and animals, providing terrestrial habitats for life.

When the first single-celled organisms appeared on Earth, more than 3 billion years ago, they fed upon carbohydrates—sugars—dissolved in the sea. The sugars had their origin in chance chemical reactions. Life, however, multiplied exponentially; one cell made two, two made four, four made eight, and so on. Self replication is the essence of life. It was inevitable that burgeoning organisms in the sea would outstrip their catch-as-catch-can food supply It would seem that life was doomed to a dead end, but before the sugars ran out, certain organisms evolved the ability to use the energy of sunlight to synthesize carbohydrates from carbon dioxide and water, a chemical reaction called photosynthesis, catalyzed by chlorophyll. And so the first plants appeared on Earth, manufacturing their own fuel. No longer did those earliest organisms live a hunter-gatherer existence. scrounging fuel from the sea; now they settled dowm and became farmers, so to speak, making their own food. And the cells that could not do photosynthesis fed upon cells that could. The planet greened, first with photosynthesizing algae in the sea, later with multicelled land plants.