NO. I ASTROPHYSICAL OBSERVATORY, 1895 TO I955 — ABBOT 



phragm combination invented, 

 instantly exchangeable, for bo- 

 lometer work. 



17. A continuously variable rotating 



sector invented, of accurate 

 ratio, for photometry. 



18. A pair of telephoto cameras in- 



vented, electrically connected, 

 for simultaneous exposure on 

 flying objects. The invention 

 comprises a belt-focal-plane 

 shutter, surrounding film spools. 

 Shutter and spools operated by 

 a long spring and clockwork. 

 The observer and assistant sepa- 

 rated by a measured base line 

 keep both cameras trained. Ob- 

 server makes a series of expo- 

 sures by a trigger, and second 

 camera is simultaneously 

 exposed. 



19. Apparatus invented for prevent- 



ing "personal equation" in ob- 

 serving sudden phenomena. The 

 observer notes the sector where, 

 not the times when, the event 

 occurs. 



20. Automatic recording radiation 



instruments invented. 



No published description. 



One camera on public exhibition in 

 Langley case in the West Hall of 

 the Arts and Industries Building, 

 Smithsonian Institution. 



Apparatus on public exhibition in 

 Langley case (see above). 



Annals, vol. 7, pp. 144-146, 1954. 



Past 2. — Various itwentions, mainly for military use in World Wars I and II 



Variable-speed power-transmis- 

 sion mechanism, Claim i, al- 

 lowed "The combination of a 

 driving element, a driven ele- 

 ment, and means for establish- 

 ing, and maintaining constantly, 

 exactly and positively, a desired 

 speed ratio between said ele- 

 ments, or for continuously vary- 

 ing said ratio." 



Variable-speed governor. For a 

 clockwork to be of speed varied 

 at will, without stopping, and 

 continuously, through a several- 

 fold range. Used for a Navy 

 project. 



Self-propelled rotating projectile 

 for smooth-bore guns. Combina- 

 tion with smooth-bore ordnance. 



U. S. Patent No. 893416 of July 

 1908. 



14, 



U. S. Patent No. 2367254 of Janu- 

 ary 16, 1945. 



U. S. Patent No. 1380172, and U. S. 

 Patent No. 1380171, both of May 31, 

 1921. 



