SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I3I 



8. 



9- 

 10. 



Gyroscopic navigation instrument. 

 For measuring differences in 

 longitude and latitude without 

 sun or star observations. 



Compass and magnetic-dip indi- 

 cator. Both this and No. 4 

 used the principle of neutral 

 flotation in liquid, and electric 

 current therethrough for operat- 

 ing. Germans independently dis- 

 covered the mathematical prin- 

 ciple of No. 4 and built such a 

 machine but it failed. An Eng- 

 lishman from National Labora- 

 tory examined patent of No. 4, 

 and said it carried superior fea- 

 tures. Work on it stopped with 

 the Armistice, November 1918. 



Instrument for navigating air- 

 planes by daylight star observa- 

 tions. Stars can be seen with a 

 small telescope in daylight if 

 the telescope field contains the 

 star image. The instrument 

 could be set to contain the star 

 in its field before observing. 

 Twelve -Stars and two planets 

 were easily observed by W. H. 

 Hoover in New Mexico. E. D. 

 McAlister observed Altair from 

 airplane at 21,000 feet. 



Instrument for automatic mapping 

 of airplane course over ocean, 

 to enable return to course of 

 mother ship. The patent, No. 

 2367254, above cited, was a part 

 of this device. 



Solar distilling apparatus. 



Solar heater. 



Solar heat collector. 



General Electric Patent No. 1501^ 

 to C. G. Abbot July 15, 1924. 



General Electric Patent No. 1533683 

 to C. G. Abbot April 14, 1925. 



Built and tested secretly. Never pub- 

 lished. 



Built and tested secretly. Never pub- 

 lished. 



Patent No. 2141330, December 27, 1938. 

 Patent No. 2247830, July i, 1941. 

 Patent No. 2460482, February i, 1949. 



SECTION B 

 Part i. — Researches 



I. Bolometric map of infrared solar 

 spectrum. 



2. Dispersion of rock-salt and fluo- 

 rite. (Six-place decimals in re- 



Annals, vol. I, pp. 5-204, 1900; vol. 5, 



p. 54. 1932. 

 Smithsonian Misc. Coll., vol. 82, No. i, 



1929. 

 -Annals, vol. i, pp. 219-237, 253-262, 



1900. 



