Architecture of the earth

The magical instruments of the astronomer reveal no element new to chemistry and show the earth to be a marvellously complete sample of the universe of matter, whether in planet, star, nebula, galaxy, or super-galaxy. Thus from earth science comes a better understanding of the universe. Geology, tracing the dramatic history of one of the celestial wanderers, deepens our concept of Time and still further broadens the foundation of a sound philosophy. Pierre Termier meant much when he wrote: "The earth declares the glory of God." He had devoted his life to a study of the stately processes that have governed the evolution of our globe through two billions of years. Yet, like other professional geologists, he found ordinary words inadequate for the new, unfamiliar ideas. Technical terms have had to be invented. Here is a difficulty when the geologist attempts to tell his story. Technicality puts a barrier between the specialists and the great public or even the beginner in the professional study of earth's history. For this trouble there is only one medicine—good-will. However, with good-will on both sides the geologist can share with others the thrills that spring from an incomparable moving picture.

The Norman Wait Harris Foundation of Northwestern University encourages effort of this twofold character: effort by the specialist to be an adequate reporter; effort by listener and reader to imagine truly the materials and processes that have made the earth what it is. The following pages represent the slightly expanded material of lectures on "The Crust of the Earth," given under the auspices of the Foundation in May, 1937. Special emphasis is placed on discoveries and clarifications made since the opening of the present century: crucially important discoveries by field geologists; clarifications due to the recent, spectacular growth of the young science of geophysics. More and more the exquisite tools of the modern physical and chemical laboratories are being used to guide the field naturalists in the interpretation of what he sees outdoors. 

A leading purpose of this book is to summarize the new discoveries. There is offered to geologists and to other men of science a picture of the earth which has come out of a synthesis of facts, won by both observers in the field and their colleagues of the laboratory. The general reader will have trouble here and there in following an argument, but it is hoped that he too, without intolerable effort in an unfamiliar field, will be able to see how modern research is molding thought about our planetary home.

The writer wishes to record his appreciation of the great courtesy extended by Dr. T. W. Koch and other officers of the Harris Foundation and by members of the Geological Department of Northwestern University during the period of the lectures; also to Louise Haskell Daly and Professor Kirtley F. Mather for valued bettering of the manuscript, both in substance and expression; to Edward Schmitz for care in drafting many of the illustrations; to Dr. John M. Ide and Dr. Francis Birch of Harvard University for permission to quote new, in part unpublished records from their path-making researches on the physical properties of rocks; to various authors and publishers who have graciously permitted copying and re-publication of a number of drawings; and to others who have supplied original material for graphic illustrations.