6i6 



THE POPULAR SCIENCE MONTHLY 



meeting of the British Association are 

 being held as prisoners of war in Eng- 

 land. But at the meeting of the as- 

 sociation after the outbreak of war 

 these same scientific men received hon- 

 orary degrees from a British university 

 with special applause. 



When public opinion in regard to 

 war is so subject to emotional control, 

 the way of wisdom is to avoid war and 

 the conditions leading to war, even to 

 the extent of holding that there never is 

 a good war or a bad peace. The only 

 gleam of hope in the present situation 

 is that public sentiment in this country 

 is against war and against the nations 

 which, rightly or wrongly, are supposed 

 to be the aggressors, and that each na- 

 tion is anxious to disclaim responsibil- 

 ity for the existing chaos. In its incep- 

 tion the war was an affair of militarists 

 and diplomatists, and Germany was un- 

 fortunate in combining these two 

 classes in the same clique. All would 

 have been different if there had been a 

 Bismarck to whom the military machine 

 was subordinated; there might have 

 been war between Bussia and Germany, 

 but there would have been no Euro- 

 pean war. Conditions were better in 

 Great Britain, and diplomacy tried to 

 prevent war, but when war came then 

 diplomacy had involved the people in 

 its tricks. 



Suddenly out of its stale and drowsy 



lair, the lair of slaves, 

 Like lightning it leo't forth half 



startled at itself, 

 Its feet upon the ashes and the rags, 



its hands tight to the throats of 



kings. 



But none of us can see clearly in the 

 storm and in the darkness. It is our 

 helplessness, the horror of it all, the 

 pity of it all, that overwhelm us. The 

 only safe conclusion is that the work of 

 the world for science and for civiliza- 

 tion must be maintained. We may well 

 honor the Paris Academy of Sciences 

 for continuing its meetings when the 

 enemy were at the gates of Paris and 

 the government had fled; the scientific 

 men and scholars of Strassburg for 

 opening the sessions of the university 

 at the usual time. And most of all it 



is our business to carry forward the 

 flickering torch. The f„ct that the 

 greatest nations of Europe will be pre- 

 vented, not only this year but for some 

 years to come, from doing their share 

 of scientific work, makes it all the more 

 necessary that the scientific men, the 

 scientific institutions and the scientific 

 journals of this country should main- 

 tain and increase their efforts. 



CBYSTALS AND X-RAYS 



As part of the celebration of the one 

 hundred and fiftieth anniversary of the 

 founding of Brown University a series 

 of meetings and courses of lectures 

 have been arranged. One of the most 

 interesting of these was a series of four 

 lectures by Professor William Henry 

 Bragg, E.R.S., of the University of 

 Leeds, discussing the important work 

 that has recently been done on the phe- 

 nomena resulting from the passage of 

 X-rays through crystals. 



Two years ago an experiment of great 

 beauty and extreme scientific impor- 

 tance was successfully carried out in 

 the physical laboratories at Munich by 

 Friedrich and Knipping, acting on a 

 brilliant suggestion made by Laue, a 

 member of the staff of the university at 

 Zurich. To put it very briefly the ex- 

 periment consisted in the exposition of 

 the interference effects accompanying 

 the passage of X-rays through crystals, 

 and it proved that X-rays consist of 

 extremely short waves in the ether. It 

 is now clear that X-rays are exactly the 

 same thing as light rays, except that 

 the wave length is roughly ten thousand 

 times smaller. The significance of this 

 discovery can not be compressed into 

 a single sentence because it points in 

 several independent directions. 



In the first place, the result is of the 

 greatest importance in connection with 

 the general theories of radiation. The 

 undulatory theory of light has been ex- 

 traordinarily successful in correlating 

 experimental facts. Towards the end 

 of the last century it seemed as if it 

 had conquered all the great problems of 

 physical optics. More recently it has 



