Third Bibliography and Index for the Philosophy of Geology

The following bibliography and index have the same scope and structure as the two preceding issues. The categories of writings here cited are also the same as listed in the front portion of the second bibliography

Second Bibliography and Index for the Philosophy of Geology

The body of writings on the philosophy and history of geology has grown in a remarkable way since the end of the Second World War. There is no obvious explanation for this quickening of interest in what are surely the most academic aspects of a science best known for its practical applications. Influences arising both from within and from outside the geological profession have probably been responsible. It is a matter of record that many departments of geology, upon resuming full-time operations after the war, decided not to go on moving in the old curricular ruts. The new courses, even those in the classical geological disciplines, became more analytical, relying less and less upon the memorization of factual material. This trend has called for a rethinking of the basic principles of geology. There has even been some pecking and scraping around that mossy Victorian cornerstone of historical geology, the principle of the uniformity of nature-and some of us have been astonished to find that the shape of the moss is not the shape of the stone

A Human Skeleton Found Near Carrollton, Texas

Several months ago a human skeleton was taken from a gravel and sand pit in northwestern Dallas County. The bones were embedded in sand about 6 feet below the surface of a terrace spur on the south side of Denton Creek, a branch of Elm Fork of the Trinity River

Notes on the History and Philosophy of Science

In October of 1960 a small group of geologists and philosophers met in Dallas to discuss problems related to the scope and philosophy of geology. Among the subjects considered were homotaxis and geochronometry, the classification of faults, explanation in historical geology, the principle of simplicity, the principle of uniformity, the methodology of geologic mapping, the contribution of geology to general thought, and the scope of the earth sciences. Messrs. William E. Benson of the National Science Foundation, Frederick Betz, Jr. of The Geological Society of America, James Gilluly of the U. S. Geological Survey, J.M. Harrison of the Geological Survey of Canada, Harry H. Hess of Princeton University, Mason L. Hill of the Richfield Oil Company, M. King Hubbert of the Shell Development Company, Luna Leopold of the U. S. Geological Survey, Eugene Herrin of Southern Methodist University, and Claude C. Albritton, Jr. represented the geological sciences. The philosophers, outnumbered but not outgunned, were professors Nelson Goodman of the University of Pennsylvania, Carl G. Hempel of Princeton and John H. Kultgen of Southern Methodist University

Application of Positive Feedback Techniques to Charge-Sensitive Preamplifiers

The application of positive feedback techniques to charge-sensitive preamplifiers for the purpose of improving their performance characteristics and versatility is considered. Improvements in sensitivity of charge gain in input capacitance, preamplifier output pulse rise-time, and ability to terminate long input cables are discussed. In each case, theoretical developments are carried out in order to determine the optimum positive feedback conditions. A practical charge-sensitive preamplifier design is discussed and the effects of applying positive feedback are delineated. For the experimental preamplifier, the application of positive feedback resulted in a reduction in charge gain sensitivity to input capacitance changes of almost an order of magnitude for a 100 pf. change in input capacitance. The output pulse rise-time without positive feedback was approximately 90 nsec. with 100 pf. detector capacitance. This was reduced to approximately 15 nsec. by the application of positive feedback. The equivalent noise charge of the experimental preamplifier was approximately 4 x 10-17 rms coulombs with 0 pf. detector capacitance and for 1 μsec. RC-RC shaping. The use of positive feedback did not affect the noise performance. The experimental preamplifier was not designed with low noise as a prime requisite. The application of positive feedback was shown to provide tremendous improvement in the ability of the experimental preamplifier to terminate long input cables. Different cables with characteristic impedances, Z0, from 50 ohms to 950 ohms were attached to the input of the preamplifier. Theoretical equations were developed for the positive feedback conditions which would cause the input impedance of he preamplifier to be equal to the Z0 of the cables. Experimental results provided excellent confirmation of the theory. Output signal waveforms, which formerly were completely useless for normal pulse-shaping networks, were in many cases essentially undistorted after correct use of the cable-termination theory

A New Center for Scientific Studies In the Southwest

On October 14, 1957, the charter of The Graduate Research Center, Inc. was approved and filed in the Office of the Secretary of State at Austin, Texas. In the words of the charter, this corporation is formed to support and encourage the advancement of knowledge in the pure and applied sciences, and to aid in the conduct of research and investigations in those fields at Southern Methodist University

The Washita Group in the Valley of the Trinity River, Texas: A Field Guide

Our present understanding of Washita biostratigraphy in the north Texas area is founded upon the pioneer work of W. S. Adkins, W. M. Winton and Gayle Scott. Their work was published from about 1919 to 1932, and as is inevitable many of the outcrops studied by them are no longer accessible and several new exposures have added to our knowledge of the local biostratigraphy. It is the purpose of this field guide to acquaint geologists with those localities which are now accessible and which typify Washita stratigraphy in Tarrant and southern Denton counties

ARAC-3, A New Generation Emergency Response Modeling System

A description of the new ARAC-3 (Atmospheric Release Advisory Capability) modeling system is presented. Among the major new capabilities are a prognostic forecast model and entirely new diagnostic and dispersion models. Various components of the system are being tested to determine their performance both individually and within an integrated setting. When completed in 1999, ARAC-3 will contain all the features of the current ARAC-2 system as well as new capabilities that will enable ARAC to function as a state-of-the-art emergency response system well into the next decade