270 KIMBALL: ATMOSPHERIC HAZINESS DURING 1912 



the occurrence of any unusually hazy or smoky conditions of the atmos- 

 phere, or of unusually brilliant colors at sunrise or sunset. 



4. Extracts from the meteorological reports of observers in British 

 Columbia, which were kindly forwarded to the Chief of the U. S. Weather 

 Bureau by the Director of the Meteorological Service of Canada. 



5. Extracts from the logs of ships sailing on the North Pacific Ocean 

 in June, 1912. 



6. Replies to a circular letter dated December 28, 1912, addressed to 

 members of the Astronomical and Astrophysical Society of America, and 

 requesting copies of any observational data they might have relative to 

 a possible diminution in atmospheric transparency after June 1, 1912. 



7. Observations of skyhght polarization made by me at Mount 

 Weather, Virginia, and Santa Fe, New Mexico, and pyrheliometric 

 measurements made under my supervision at Mount Weather, Virginia, 

 Madison, Wisconsin, and Lincoln, Nebraska. 



Fall of volcanic ash. Katmai Volcano which is in the Aleutian 

 Range, Alaska, latitude 58°N., longitude 155°W., approximately, 

 became violently eruptive on the afternoon of June 6, 1912, and 

 continued in a state of great activity for about three days; it was 

 more or less active until the end of October and perhaps until 

 the end of the year. As a result of these eruptions volcanic ash 

 fell between June 6 and June 10 over an area extending in latitude 

 from Rampart, Alaska, latitude 65^°N to Loring, Alaska, latitude 

 55|°N and in the state of Washington to latitude 48^°N. In 

 longitude the fall extended from Nushagak, Alaska, longitude 

 158|°W., to Chicken, Alaska, longitude 142°W., to Loring, Alaska, 

 longitude 131° W., and in the state of Washington to longitude 

 122^° W. There also appears to have been a fall of very fine 

 dust at Mount Wilson, California, on August 3-4, which dis- 

 colored the silver film on the coelostat mirrors. 



Haze and smoke. The observations show that a hazy or smoky 

 period set in over British Columbia on June 6-8, and over the 

 northwestern part of the United States on June 8-10. This 

 continued until June 11-12, and in the meantime gradually ex- 

 tended eastward. A second hazy or smoky period set in over 

 British Columbia on June 18-20, and over the northwestern part 

 of the United States at about the same time. It extended gradu- 

 ally eastward and southward, and diminished in intensity before 

 the end of the month, especially in the states west of the Rocky 

 Mountains. 



