SOME CONSIDERATIONS ON THE BALLISTICS OF A 

 GUN OF SEVENTY-FIVE-MILE RANGE.^ 



By ARTHUR GORDON WEBSTER. Ph.D., Sc.D., LL.D. 

 {Read April 20, igi8. Received May 2, 1919.) 



On the afternoon of March 23, 1918, the civilized world was 

 astounded by the news that the Germans were bombarding Paris. 

 Inasmuch as it was known that the nearest point at which the Ger- 

 man lines approached Paris was over seventy miles distant, curiosity 

 was universal as to how this result was accomplished, and the most 

 unlikely and absurd hypotheses were suggested. 



The writer, among others, was asked whether or not the result 

 was likely to be due to an aerial torpedo. The next day revealed the 

 truth, which was, simply, that the Germans had really built a gun 

 which carried a projectile this hitherto unheard-of distance. 



It has since been determined that the gun is situated in the Forest 

 of St. Gobain in the neighborhood of Laon, at a distance of about 

 120 kilometers or seventy miles. 



At this distance the curvature of the earth causes one end of such 

 a line to be about a half mile below the horizon at the other end, so 

 that it is impossible to see the target from the gun or vice versa ; 

 there being no mountains of any such height in the whole region, 

 visual aiming would be quite out of the question. 



I wish, first, to call the attention not only to the remarkable bal- 

 listic achievement of the Germans in so far surpassing previous 

 ranges but also to the unique opportunity possessed. It is obvious 

 that precision of aim at such a distance is well-nigh impossible and 

 that the only hope of effecting any damage lies in the possession of 

 a very large and valuable target. Little has been allowed to come 

 through the cable as to the damage done by these long-range shots, 

 but enough has been learned in order to see their terrible potential- 



1 Contribution from the Ballistic Institute, Clark University, No. 2. 



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