Civil War: Acoustic Shadows

Military Review,  July-August, 2003  by Richard L. Kiper

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Charles D. Ross, White Mane Books, Shippensburg, PA, 2001, 174 pages, $24.95.

In Civil War: Acoustic Shadows, Charles D. Ross explains how the scientific occurrence called "acoustic shadow" affected the critical decisions of commanders during seven Civil War battles. Several Civil War reports mention acoustic shadow, which Mark Boatner, in The Civil War Dictionary (David McKay Company, Inc., New York, 1980), defines as "a phenomenon that results in sound being inaudible to persons a short distance from the source while the same sound may be heard over a hundred miles away...." As Ross demonstrates through terrain and weather analysis and the use of official reports, such a phenomenon did occur several times during the Civil War.

In an era when battlefield telegraphy was impractical, sound was the primary means by which commanders grasped what was happening on the battlefield. Were that sound masked or absorbed by hills, vegetation, wind, or atmosphere, what an individual standing in a particular location hears could be severely affected. On the battlefield such effects could be disastrous.

While Ross presents a clear picture of the effects of acoustic shadow on the battles he analyzes, his explanation of why the phenomenon occurs is not as clear as be intends. His attempt to simplify the explanation of the complexity of sound is commendable, but his explanations of such principles as rarefaction (movement of molecules) and the effect of temperature on refraction remain rather difficult to follow.

Peripherally, Ross mentions that several commanders did not actively seek information when something appeared amiss nor did they alert their senior commanders when they engaged in battle. The reasons why they did not keep their superiors informed should have received more attention than Ross gives. Although Ross did not mean for Acoustic Shadows to be a detailed battle or leadership study, he should have taken to task commanders who, despite not hearing a battle, should have known one was taking place.

As Ross explains, acoustic shadow is caused by specific conditions. He could have aided the reader by explaining why, under similar conditions, the effect did not occur. For example, Chancellorsville was fought in May 1863. The battle of the Wilderness occurred in almost the exact location one year later. Why was there no acoustic shadow in the second battle?

Better maps would have helped readers understand how terrain could produce or affect acoustic shadow. Ross uses several maps from Battles and Leaders of the Civil War, edited by Robert Underwood Johnson and Clarence Clough Buel, (Harrisburg, PA: Archive Society, 1991) that, because of the extensive detail, make it difficult for the reader to follow along with the narrative.

Overall this is an interesting book. Acoustic shadow is known to Civil War historians and students of particular battles, but it has not been previously examined in its entirety. Certainly Ross has provided an excellent starting point for an understanding of this scientific phenomenon.

LTC Richard L Kiper, USA Retired, Ph.D., Leavenworth, Kansas

COPYRIGHT 2003 U.S. Army CGSC
COPYRIGHT 2008 Gale, Cengage Learning