GEOPHYSICAL LABORATORY.^ 



Arthur L. Day, Director. 



Throughout the war period the research problems upon which this 

 Laboratory has been engaged since its estabhshment were all laid 

 aside and our attention was concentrated upon the one problem of 

 developing in this country an adequate source of supply of optical 

 glass for the instruments of precision required by the Army and Navy 

 for war purposes. Our responsibility included not only the develop- 

 ment of methods and processes, the selection of raw material, and the 

 manner of treatment of the product, but also included the factory con- 

 trol of manufacturing operations. This meant, of course, that most of 

 the actual work was done in manufacturing plants more or less remote 

 from Washington, so that not even a semblance of progress could be 

 maintained in the direction of our regular scientific researches. 



The particular war task to which we were assigned was also peculiar 

 in that nothing of the kind had been seriously undertaken in this 

 country before. It had been our habit to import the various kinds 

 of optical glass required for instruments of precision, and we had 

 become completely dependent upon foreign sources for this indis- 

 pensable material. Such dependence carries with it obvious elements 

 of danger in the event of war with a foreign nation and not inconsider- 

 able limitations in time of peace, for there is not only commercial 

 disadvantage but a lack of incentive in the development of new vari- 

 eties of lens systems and in the other applications of optical glass if 

 the entire product comes ready-made from abroad and even the limita- 

 tions of manufacture are unknown. Many possible applications to 

 the problems of peace as well as of war will remain undeveloped, and, 

 in fact, have remained untouched in this country hitherto, because of 

 this lack of acquaintance wdth the possibilities of development and 

 application of special glasses. It will hardly be necessary to indicate 

 in detail how helpless the nation is in event of war when all glass used 

 in fire-control instruments is of foreign origin, and even the instruments 

 themselves are largely of foreign design. 



Not only did these limitations exist in acute form at the time when 

 the United States entered the war in 1917, but substantially all the 

 processes of manufacture of glass of this quality had been held secret 

 in those countries where production had been most successful, either 

 under the protection of Government monopoly or because of com- 

 mercial expediency. In fact, not even the pressure of war proved 

 adequate to break down this wall of secrecy and bring to our shores in 

 our moment of need the technical information necessary to enable us to 

 take up at once the manufacture of successful glass. 



^Situated in Washington, District of Columbia. 



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