368 



SCIENCE 



[N. S. Vol. LI. No. 1319 



The Curtiss Company will be among the 

 first to acknowledge a properly authenticated 

 record beating the one it now holds and in a 

 true competitive spirit and for the benefit of 

 aviation attempt to better it at the first 

 opportunity. J. G. Coffin, 



Director of Aeronautical Research 

 CuBTiss Aeronautical & Motor Coepobation, 

 Garden City, L. I., N. Y. 



CONCERNING BALLISTICS 



. To THE Editor of Science: For sufficient 

 reasons I was unable to attend the meeting of 

 the American Association, and so was not so 

 fortunate as to hear Major Hull's very valu- 

 able and interesting address on ballistics, nor 

 Professor Ames's extremely scholarly and clear 

 address on Einstein's theory. However I have 

 read Professor Hull's address in Science with 

 great pleasure. In it he is good enough to 

 speak of my pressure gauge for guns, but says 

 that its use appears to be limited to the cases 

 of guns that can be rigidly clamped during 

 the explosion. I hope to demonstrate shortly 

 that there is no such limitation. Over a year 

 ago I was offered the use of a six-inch gun at 

 Aberdeen to put my gauge on, and Admiral 

 Earle has at last taken an interest in my re- 

 sults and has manifested a willingness to as- 

 sist me. The coming of the armistice, how- 

 ever, removed so much money and personnel 

 from Aberdeen that nothing came of it. 



I should have been pleased if Major Hull 

 could have seen fit to call attention to the fact 

 that I was the first person to publish trajec- 

 tories of " la grosse Bertbi " that bombarded 

 Paris two years ago. The bombardment be- 

 gan on March 23, 1918. The next week I be- 

 gan to deliver lectures on exterior ballistics, 

 and in a few days we had a number of trajec- 

 tories calculated. In four weeks from that 

 date I read a paper at the meeting of the 

 American Philosophical Society in Philadel- 

 phia, at which I showed a number of trajec- 

 tories. I used the height function for the 

 density as given in Major Hull's address, and 

 at that time it had never been used by either 

 the United States Army or N"avy. I showed 

 my results to Major Moulton, who was just be- 



ginning his distinguished service in the army, 

 and he showed much interest. Later he ad- 

 vised me not to publish them, as such calcula- 

 tions were now " a matter of routine." 



I reminded him that although they may be 

 such now, they were not when I read the paper. 

 I have also seen in French journals pictures 

 with articles apparently written by experts 

 which would lead one to believe that there are 

 discontinuities in the atmosphere, or that it 

 stopped suddenly a few miles up. In a recent 

 letter from M. Henri Le Chatelier, reg-arding 

 my paper, he says that the French had made 

 guns with an initial velocity of 1,200 meters 

 per second, but had not thought of using them 

 for high fire, as they were intended for 

 penetration of ships armor. "We also con- 

 structed curves showing the decrease of den- 

 sity upon both the isothermal and adiabatic 

 hypotheses, neglecting and taking account of 

 the variation in gravity, as given in my book 

 on Dynamics, and also the .observed values as 

 kindly furnished me by Professor Humphreys. 

 Unfortunately I was requested to keep the 

 number of figures down, and these were not 

 printed. I should be glad to send the paper 

 to any one interested. The gauge paper is un- 

 fortunately exhausted. I may say that M. 

 Sugot, the chief engineer of the Commission 

 de Gavre, told me last summer that ballisti- 

 cians had been waiting fifty years for my in- 

 strument, and that the publication of my 

 curves had rendered useless all the theoretical 

 work of ballisticians on interior ballistics. 

 Of course that is not so, but I hope next month 

 to show how this gauge answers all questions 

 that can be asked on the subject. I think I 

 was the first professor to give lectures on bal- 

 listics, both interior and exterior, at an Ameri- 

 can university. 



My ballistic institute is having hard sled- 

 ding. At first encouraged by a vote of the 

 N'aval Consulting Board, turned down by the 

 Honorable the Secretary of the I^avy (with- 

 out a word of regret), financed by a great arms 

 company for awhile, helped by the Bache and 

 Eumford Funds, it looks as if it would have 

 to be given up for lack of money. "When we 

 began I had one assistant, one machinist and 



