At the very outset we may well ask what constitutes the distinction between prehistoric and historic epochs - a distinction which has been constantly implied in much that we have said. The reply savors somewhat of vagueness. It is a distinction having to do, not so much with facts of human progress as with our interpretation of these facts. When we speak of the dawn of history we must not be understood to imply that, at the period in question, there was any sudden change in the intellectual status of the human race or in the status of any individual tribe or nation of men. What we mean is that modern knowledge has penetrated the mists of the past for the period we term historical with something more of clearness and precision than it has been able to bring to bear upon yet earlier periods. New accessions of knowledge may thus shift from time to time the bounds of the so-called historical period. The clearest illustration of this is furnished by our interpretation of Egyptian history. Until recently the biblical records of the Hebrew captivity or service, together with the similar account of Josephus, furnished about all that was known of Egyptian history even of so comparatively recent a time as that of Ramses II. (fifteenth century B.C.), and from that period on there was almost a complete gap until the story was taken up by the Greek historians Herodotus and Diodorus. It is true that the king-lists of the Alexandrian historian, Manetho, were all along accessible in somewhat garbled copies. But at best they seemed to supply unintelligible lists of names and dates which no one was disposed to take seriously. That they were, broadly speaking, true historical records, and most important historical records at that, was not recognized by modern scholars until fresh light had been thrown on the subject from altogether new sources.

These new sources of knowledge of ancient history demand a moment's consideration. They are all-important because they have been the means of extending the historical period of Egyptian history (using the word history in the way just explained) by three or four thousand years. As just suggested, that historical period carried the scholarship of the early nineteenth century scarcely beyond the fifteenth century B.C., but to-day's vision extends with tolerable clearness to about the middle of the fifth millennium B.C. This change has been brought about chiefly through study of the Egyptian hieroglyphics. These hieroglyphics constitute, as we now know, a highly developed system of writing; a system that was practised for some thousands of years, but which fell utterly into disuse in the later Roman period, and the knowledge of which passed absolutely from the mind of man. For about two thousand years no one was able to read, with any degree of explicitness, a single character of this strange script, and the idea became prevalent that it did not constitute a real system of writing, but only a more or less barbaric system of religious symbolism. The falsity of this view was shown early in the nineteenth century when Dr. Thomas Young was led, through study of the famous trilingual inscription of the Rosetta stone, to make the first successful attempt at clearing up the mysteries of the hieroglyphics.

This is not the place to tell the story of his fascinating discoveries and those of his successors. That story belongs to nineteenth-century science, not to the science of the Egyptians. Suffice it here that Young gained the first clew to a few of the phonetic values of the Egyptian symbols, and that the work of discovery was carried on and vastly extended by the Frenchman Champollion, a little later, with the result that the firm foundations of the modern science of Egyptology were laid. Subsequently such students as Rosellini the Italian, Lepsius the German, and Wilkinson the Englishman, entered the field, which in due course was cultivated by De Rouge in France and Birch in England, and by such distinguished latter-day workers as Chabas, Mariette, Maspero, Amelineau, and De Morgan among the Frenchmen; Professor Petrie and Dr. Budge in England; and Brugsch Pasha and Professor Erman in Germany, not to mention a large coterie of somewhat less familiar names. These men working, some of them in the field of practical exploration, some as students of the Egyptian language and writing, have restored to us a tolerably precise knowledge of the history of Egypt from the time of the first historical king, Mena, whose date is placed at about the middle of the fifth century B.C. We know not merely the names of most of the subsequent rulers, but some thing of the deeds of many of them; and, what is vastly more important, we know, thanks to the modern interpretation of the old literature, many things concerning the life of the people, and in particular concerning their highest culture, their methods of thought, and their scientific attainments, which might well have been supposed to be past finding out. Nor has modern investigation halted with the time of the first kings; the recent explorations of such archaeologists as Amelineau, De Morgan, and Petrie have brought to light numerous remains of what is now spoken of as the predynastic period - a period when the inhabitants of the Nile Valley used implements of chipped stone, when their pottery was made without the use of the potter's wheel, and when they buried their dead in curiously cramped attitudes without attempt at mummification. These aboriginal inhabitants of Egypt cannot perhaps with strict propriety be spoken of as living within the historical period, since we cannot date their relics with any accuracy. But they give us glimpses of the early stages of civilization upon which the Egyptians of the dynastic period were to advance.

It is held that the nascent civilization of these Egyptians of the Neolithic, or late Stone Age, was overthrown by the invading hosts of a more highly civilized race which probably came from the East, and which may have been of a Semitic stock. The presumption is that this invading people brought with it a knowledge of the arts of war and peace, developed or adopted in its old home. The introduction of these arts served to bridge somewhat suddenly, so far as Egypt is concerned, that gap between the prehistoric and the historic stage of culture to which we have all along referred. The essential structure of that bridge, let it now be clearly understood, consisted of a single element. That element is the capacity to make written records: a knowledge of the art of writing. Clearly understood, it is this element of knowledge that forms the line bounding the historical period. Numberless mementos are in existence that tell of the intellectual activities of prehistoric man; such mementos as flint implements, pieces of pottery, and fragments of bone, inscribed with pictures that may fairly be spoken of as works of art; but so long as no written word accompanies these records, so long as no name of king or scribe comes down to us, we feel that these records belong to the domain of archaeology rather than to that of history. Yet it must be understood all along that these two domains shade one into the other and, it has already been urged, that the distinction between them is one that pertains rather to modern scholarship than to the development of civilization itself. Bearing this distinction still in mind, and recalling that the historical period, which is to be the field of our observation throughout the rest of our studies, extends for Egypt well back into the fifth millennium B.C., let us briefly review the practical phases of that civilization to which the Egyptian had attained before the beginning of the dynastic period. Since theoretical science is everywhere linked with the mechanical arts, this survey will give us a clear comprehension of the field that lies open for the progress of science in the long stages of historical time upon which we are just entering.

We may pass over such rudimentary advances in the direction of civilization as are implied in the use of articulate language, the application of fire to the uses of man, and the systematic making of dwellings of one sort or another, since all of these are stages of progress that were reached very early in the prehistoric period. What more directly concerns us is to note that a really high stage of mechanical development had been reached before the dawnings of Egyptian history proper. All manner of household utensils were employed; the potter's wheel aided in the construction of a great variety of earthen vessels; weaving had become a fine art, and weapons of bronze, including axes, spears, knives, and arrow-heads, were in constant use. Animals had long been domesticated, in particular the dog, the cat, and the ox; the horse was introduced later from the East. The practical arts of agriculture were practised almost as they are at the present day in Egypt, there being, of course, the same dependence then as now upon the inundations of the Nile.

As to government, the Egyptian of the first dynasty regarded his king as a demi-god to be actually deified after his death, and this point of view was not changed throughout the stages of later Egyptian history. In point of art, marvellous advances upon the skill of the prehistoric man had been made, probably in part under Asiatic influences, and that unique style of stilted yet expressive drawing had come into vogue, which was to be remembered in after times as typically Egyptian. More important than all else, our Egyptian of the earliest historical period was in possession of the art of writing. He had begun to make those specific records which were impossible to the man of the Stone Age, and thus he had entered fully upon the way of historical progress which, as already pointed out, has its very foundation in written records. From now on the deeds of individual kings could find specific record. It began to be possible to fix the chronology of remote events with some accuracy; and with this same fixing of chronologies came the advent of true history. The period which precedes what is usually spoken of as the first dynasty in Egypt is one into which the present-day searcher is still able to see but darkly. The evidence seems to suggest than an invasion of relatively cultured people from the East overthrew, and in time supplanted, the Neolithic civilization of the Nile Valley. It is impossible to date this invasion accurately, but it cannot well have been later than the year 5000 B.C., and it may have been a great many centuries earlier than this. Be the exact dates what they may, we find the Egyptian of the fifth millennium B.C. in full possession of a highly organized civilization.

All subsequent ages have marvelled at the pyramids, some of which date from about the year 4000 B.C., though we may note in passing that these dates must not be taken too literally. The chronology of ancient Egypt cannot as yet be fixed with exact accuracy, but the disagreements between the various students of the subject need give us little concern. For our present purpose it does not in the least matter whether the pyramids were built three thousand or four thousand years before the beginning of our era. It suffices that they date back to a period long antecedent to the beginnings of civilization in Western Europe. They prove that the Egyptian of that early day had attained a knowledge of practical mechanics which, even from the twentieth-century point of view, is not to be spoken of lightly. It has sometimes been suggested that these mighty pyramids, built as they are of great blocks of stone, speak for an almost miraculous knowledge on the part of their builders; but a saner view of the conditions gives no warrant for this thought. Diodoras, the Sicilian, in his famous World's History, written about the beginning of our era, explains the building of the pyramids by suggesting that great quantities of earth were piled against the side of the rising structure to form an inclined plane up which the blocks of stone were dragged. He gives us certain figures, based, doubtless, on reports made to him by Egyptian priests, who in turn drew upon the traditions of their country, perhaps even upon written records no longer preserved. He says that one hundred and twenty thousand men were employed in the construction of the largest pyramid, and that, notwithstanding the size of this host of workers, the task occupied twenty years. We must not place too much dependence upon such figures as these, for the ancient historians are notoriously given to exaggeration in recording numbers; yet we need not doubt that the report given by Diodorus is substantially accurate in its main outlines as to the method through which the pyramids were constructed. A host of men putting their added weight and strength to the task, with the aid of ropes, pulleys, rollers, and levers, and utilizing the principle of the inclined plane, could undoubtedly move and elevate and place in position the largest blocks that enter into the pyramids or - what seems even more wonderful - the most gigantic obelisks, without the aid of any other kind of mechanism or of any more occult power. The same hands could, as Diodorus suggests, remove all trace of the debris of construction and leave the pyramids and obelisks standing in weird isolation, as if sprung into being through a miracle.