December 1, 1922] 



SCIENCE 



639 



Instruments used in the observatdon and tracking 

 of targets for securing data for precision fire 

 ■of seacoast batteries. 



Observation and computing instruments for use 

 with anti-aircraft batteries. 



(FranTcford Arsenal Optical Laboratory) 

 Instrument for the examination of optical glass 



(designed by G. W. Mofatt). 

 Universal prism testing instrument (designed by 



G. W. Mofatt). 



4. U. S. Coast and Geodetic Sukvey 

 Astronomical transit (Bamberg). 

 Theodolite (Troughton & Simms). 

 Eepeating theodolite (Berger). 



Precise level. 

 Vertical circle. 

 Vertical collimator. 

 Navigating sextant. 

 Electric signal lamp. 

 Heliograph (heliotrope). 

 Theodolite-magnetometer. 

 Dip circle. 

 Magnetograph. 



5. Baxisch & LoiiB Optical Company 

 TJarge constant deviation spectroscope. 

 Constant deviation spectroscope for chemists. 

 Pocket spectroscopes. 



Monochromator. 



Color mixing and comparing apparatus. 



Two field monochromator. 



Comparison photometer. 



Martens photometer. 



Photometer stand. 



New Abbe refractometer. 



Dipping refractometers. 



Colorimeter. 



Hemoglobinometer. 



Aspheric condenser. 



Dioptrometer. 



Field telemeter. 



6. De. Haeby S. Geadle 

 Instrument for the determination of areas of 



retinal correspondence. 

 7. BuEEAu OP Standaeds (Badiometey Section) 

 Stellar spectral radiometer (Coblentz). 



8. A. Ames, Je., and Blanche Ames 

 -Color standard. 



9. Society G^nevois^ D 'Insteuments de 

 Physique 

 Constant deviation spectrometer. 

 Xength comparator for measurements in air. 

 Automatic machine for graduating micrometer 



heads, drums, cylindrical and conical surfaces. 



10. Laboeatory of Applied Science, Nela 

 Eesearch Laboratories 

 DifEuse reflectometer — ^A. H. Taylor type. 

 Photometer and special window for integrating 



spheres. 



11. Coening Glass Works 

 Light filters. 



12. Hanovia Chemical and Manufacturing 



Company 



Kalosat soft focus lens for photographic use with 



specimens of photographs taken with Kalosat. 



Fused quartz optical goods, microscopic slides, 



cover glasses, prisms, etc. 

 Special lenses of fused crystalline quartz. 



13. Coopek-Hbwitt Electric Company 

 Graded fused-quartz-to-Pyrex and fused-quartz- 



to-lead-glass joints. 

 Quartz-glass apparatus for photophysics and pho- 

 tochemistry. 

 Uviarc lamps. 

 Labare. 



14. Bureau of Standards (Aeronautic 

 Instruments Section) 

 Synchronizing type ground speed and drift indi- 

 cator. 

 Rate of climb recorder. 



15. A. H. Pfund 

 A precision rotating section, aperture variable and 

 measurable while in motion. 



16. Central Scientific Company 

 lugersoU glarimeter, new model. 



17. J. C. Hubbard 

 Gold-leaf electrometer. 



18. Bureau of Oednance, Navy Depaetment 

 Binocular collimator mark III (manufactured by 



Naval Gun Factory, Navy Yard, Washington, 

 D. C). 



19. C. P. Goeez American Optical Company 

 Polariscopes and accessories. 



Polariscopes for the analysis of sugar solutions 

 and other polarizing fluids. 



Various lamps and accessories. 



Refractometers and accessories. 



Refractometers, system Abbe, but of new and im- 

 proved design, for testing fats, oils and other 

 fluids. 



20. Warren P. Valentine 



Refractometer — Modified Abbe type, "Precision" 

 model. 



Refractometer — Modified Abbe tj'pe. 



Refractometer — Improved "Precision" model. 



Refractometer — ^Modified Butyro type, "Pat" 

 model. 

 21. Bureau of Standards (F. J. Bates) 



