THE HISTORY OF GEOPHYSICAL PROSPECTING
PART EIGHT - SOUND RANGING IN WORLD WAR ONE

Chapter 20  -  Bazzoni and the Pennsylvanians

Almost the entire group of early seismograph  experimentors marched forth from the halls and laboratories of the University of Pennsylvania. That noble institution conferred Doctorates in physics on Charles B. Bazzoni, E. A. Eckhardt, William Peter Haseman, John Clarence Karcher and Benjamin B. Weatherby. Henry Salvatori and Alexander Wolf were fellow graduates in Electrical Engineering from Pennsylvania; Salvatori changing to physics for a master's degree from Columbia University and Wolf going over to physics for his Ph D. from the California Institute of Technology. Of this distinguished group all are now living except William Peter Haseman. Only Bazzoni served with the military. Karcher, Eckhardt and Haseman helped with the war effort within the Bureau of Standards.

Three college professors from American universities were destined to become  observers of sound-ranging methods in France. Hereward Lester Cooke and Augustus Trowbridge became Professors of Physics at Princeton University the same year, 1906. Cooke, a British subject, had done his graduate work at Cambridge University. He journied across the Atlantic in 1916 to become a Captain in the Royal Engineers. Trowbridge was serving on General Pershing's staff as a Lieutenant Colonel. The third observer was Dr. Earnest E. Weibell, brilliant Harvard physicist. Weibeil was the victim of a German gas attack while serving in sound-ranging near the front in June of 1918. Three hours later he died from the effects of the gas.

Charles Blizard Bazzoni was awarded his B. S. in 1911, his M. A. in 1913 and his Ph D. in 1914, all from the University of Pennsylvania. From 1915 to 1917, Bazzoni was doing research on the structure of the atom at the University of London as a Harrison Research Fellow. He worked under O. W. Richardson and enjoyed the friendship of Niels Bohr, both of whom were later Nobel laureates in Physics. When General Pershing arrived in France with the American Expeditionary Force in 1917, he sent word to London for Bazzoni to meet him in Paris. Pershing offered Bazzoni a lieutenant's commission in the Corp of Engineers; which Bazzoni aecepted.

 Soon after he was in uniform, Dr. Bazzoni was temporarily attached to the British Sound-Ranging Division for advice and instruction under Lawrence Bragg, its commander. Captain Bragg was very gracious. He lectured to Bazzoni about varipus phases of the operations and demonstrated not only the British method but made him acquainted with the various systems tried out by the French. From this first-hand training program Bazzoni was ordered to the Sound Ranging School near Cologne and underwent the full course of instruction. In early 1918, Bazzoni was placed in the Intelligence Section of the American General Staff, working with the Corps of Engineers. His first duty was to choose between the British apparatus and one of the French systems of sound-ranging. He did not hesitate to choose the British system. In 1917 the English had substituted a platinum wire for the original Wollaston wire, otherwise the system continued to make use of the apparatus that had proven effective in 1916, including the hot-wire microphone. 

The English presented Dr. Bazzoni with complete sets of sound-ranging equipment as section after section of American Engineers were organized and set to work in the American lines. Sound-ranging in the United States Army was carried on by battalions of the 29th Engineers. The total number of personnel in these detachments at any one time rose to nearly 700 men. The detachments were in all technical matters under the command of G-2-C of GHQ, and in tactical matters under the command of the Commanding General of Army Artillery.

Sound-Ranging Section #1 went into action on March 11, 1918, on the St. Mihiel Sector, which was occupied by the First Division of American troops. Before the end of the month Section #2 was in operation in the Gargantus Sector, while Section #3 first saw action on April10th at Mont Mare. By the summer of 1918, there were six American sections active, all using British sound-ranging equipment.

The mathematics of sound-ranging had been worked out by the English and their interpretation methods and charts were made available to Dr. Bazzoni and the American sound-rangers under his command.

Eckhardt, Haseman, Karcher and McCollum, working for the Bureau of Standards, had started work in the summer of 1917 building a set of sound-ranging equipment for the American forces. The Western Electric Company had cooperated with the Bureau of Standards by furnishing instruments, equipment and some technical advice on the project; so that the American apparatus was sometimes referred to as the Western Electric apparatus. When the Acoustic Division of the Bureau of Standards announced in May of 1918, that this equipment was completed, J. C. Karcher was given the assignment of transporting the American made equipment to the War Zone. Karcher arrived in France with his sound-ranging apparatus in June of 1918, shortly after Dr. Weibell of Harvard had been killed by gas. Karcher was offered a commission in the Army Corps of Engineers which he refused. He was thereupon assigned to the American Legation in Paris and became the civilian authority responsible for the installation of the American apparatus.

The new equipment was similar to the British installation. Sound pickup from Western Electric microphones was fed into trans formers and from there was fed into a recording galvanometer. Because the British had had such excellent results with the hot-wire microphone, it was employed on an experimental basis for a time. The hot wire caused too much trouble with the transformer type equipment, so it was abandoned for the original Western Electric (cold) microphone. Karcher remained in France until December of 1918 when he crossed the channel for a week in London before sailing for the United States.

It should be pointed out in passing that had a set of Western Electric sound-ranging equipment been transported to the Texas-Louisana Gulf Coast in November of 1918, immediately folloving the war, it would have been capable of locating salt domes with only minor modifications of apparatus. So the physicists who had had the most to do with sound-ranging equipment, Bazzoni, Haseman, Karcher, Eckhardt and McColluo, were in a natural position to lead the way to the establishment of exploration seismology, which was exactly what happened but with a considerable time-lag. The principal inventor and perfector of sound-range equipment was an Englishman who makes his permanent home in Paris, namely Lucien Bull. Lucien Bull and Sir Lawrence Bragg, being pure scientists, never considered exploiting their unique primary position in sound-ranging to locate petroleum or minerals.

In due course Lieutenant Bazzoni became Captain Bazzoni. He was awarded the British Military Cross, the French Order Officer d'Acadmie and a special citation from General Pershing. In December Charles Bazzoni returned to London and on December 31, 1918, married Edith Vera Harling, who was the sister of a colleague in science at the University of London. Early in 1919, Captain Bazzoni returned to France in charge of several transit surveying parties, engaged in establishing the accuracy of the sound-ranging measurements. The coordinates worked out for any number of enemy guns was found to be quite accurate.

Had the Allied Artillery barrage sheets been built upon the information obtained from sound-ranging reports alone, the results would have been much more satisfactory. Many enemy positions were correctly located but were not hit because the Allied Artillery Command would not rely in certain instances upon the sound-ranging statistics. Sir Lawrence Bragg reports that sound-ranging worked out extremely weIl in World War Two, particularly in North Africa, where it was often the only way that enemy batteries could be located.

No exact description of German sound-rangipg equipment has come down to us. At least three different German inventors produced some sort of seismograph for the war effort of which at least to saw service on a regular operating basis. On the credit side of the ledger, there exists a report of 100 German seismic parties in existence in 1918. On the debit side of the ledger, Sir Lawrence Bragg states that some link between the military and the scientists broke down for the Germans. He also says that the Germans never developed a really good sound-ranging system. Dr. Charles Bazzoni, who spent a goodly portion of the year 1919 in checking up on the effectiveness of sound-ranging in France, holds similar views to those expressed by Sir Lawrence Bragg.

In 1916 Dr. Wilhelm Schweydar, on the staff of the Prussian Geodetic Institut of Potsdam, took his sound-ranging apparatus into the front lines and made a demonstration. He had so little encouragement from the Artiliery officers watching the demonstration that he simply picked up his sound-ranger and went back home. On November 1, 1923, Dr. Schweydar became Director of Geophysics at the Prussian Geodetic Institut. 

Ludger Mintrop tried for two years to interest the German General Staff in sound-ranging. A demonstration of his equipment in 1917 received a favorable reaction and he was allowed to start building up the sound-ranging section. In 1918 there were a considerable number of sound-ranging parties in operation on the German side but the data they presented to their artillery seems to have been largely ignored. Some of the 1918 sound-ranging crews were operating with Mintrop mechanical seismographs. Some of the 1918 sound-ranging parties were equipped with still another type of seismograph; Gerrnan inventor unknown.