0250 Thermometers. See also C 1210-1250. 



0260 Screens. 



0270 Hygrometers. See also G 1S90. 



0280 Psychrometers — Dew-point Instruments. 



0290 Evaporators. 



0300 Rain Ganges. 



0310 Anemometers. 



0320 Actinometers. 



0330 Smishiue Recorders. 



034(* Nepheloscopes — Cloud measuring- Instruments. 



0350 Electrometers and other Electrical Apparatus. 



0360 Kites. 



0370 Balloons. 



0380 Photographic Apparatus. 



0390 Sundry, not specified. 



PHYSICS OF ATMOSPHERE. 



0400 General. 



0410 Gaseous Constituents. 



0420 Impurities and Dust. 



0430 Extent. 



0440 Dynamical and Thermodynamical Theories. 



Cosmical Relations. 



0450 General. 



0460 Solar Influences. See also E 4110, 



0470 Relations to Sun Spot Period. 



0480 Lunar Influences. See also E 4880. 



0490 Planetary Influences. 



Optical Phenomena. 



For Theories see C 3200-3260, 3640. 



0500 General. 



0510 Coloration of Sky. See also C 3230. 



0520 PoUirization {See C 3250). Reflection. Refraction. 



Mirage. 



0530 Rain Band. 



0540 Halos. Coronee. Parhelia. 



0550 Rainbows, Solar. )> See also G 3220. 



0560 Rainbows, Lunar. 



0570 Fog-bows. 



Atmospheric Pressure. 



See also J 61. 

 0700 General. 



0710 Distribution at Earth's Surface — Isobars. 



0720 Distribution Vertical, 



