82 



Proceedings of the Royal Irish Academy. 



Date 



X 



" 





Eemakks. 



Mar. 27. 1912 



8,000 



— 



Spveral observations at night varying from 8,000 to 



„ 27 



20,000 



- 



20,000. 



April 12 



8,000 



- 



- 



„ 13 



.5,000 



- 



At 3.45 a.m. 



„ 13 



6,000 



- 



At 2.15 p.m. 



„ 16 



23,000 



31 



At 9.30 p.m. 



>, 1' 



5,500 



184 



About 20 observations between 6 a.m. and 4 p.m.. 



» IT 



9,000 



67 



N varying from 5,500 to 9,000, and n from 184 to 

 67. 



,,22 



41,000 



— 



At 9 p.m. Light fog. Very warm, cloudless weather. 



„ 23 



4,500 



— 



At 4.15 a.m. ' 



„ 23 

 „ 23 



12,000 

 10,000 



163 



69 



At 11.30 a.m. ^ , „ , 



UVerr warm, cloudless day. 

 At 5 p.m. 



,. 23 



19,000 



- - 



At 8.40 p.m. . 



„ 24 



12,000 



- 



At 4.15 a.m. " 



A very light fog. 



,. 24 



6,000 



149 



At 12.30 p.m. 





„ 25 



7,000 



173 



At 2.30 p.m. 





„ 25 



19,000 



17 



At 9.30 p.m. 





„ 26 



6,000 



79 



At 4.15 a.m. 



Tery fine, warm weather. 



„ 26 



5,500 



197 



At 10.30 a.m. 



„ 26 



12,000 



48 



At 7.30 p.m. 





„ 26 



= 17,000 



43 



At 9.15 p.m. 





>, 27 



13,000 



37 



At 4.15 a.m. 



Light fog. 



„ 29 



16,000 



44 



At 9.45 p.m. 





„ 30 



6,000 



- 



At 5 p.m. 



„ 31 



4,200 



— 



At 4 a.m. 



„ 31 



3,700 



~ 



At 10.30 a.m. 





momings duiing which there were " smoke " fogs, the values were high, 

 but decreased as the atmosphere became clearer. 



On one day observations •were taken during a snowstoiin. About two 

 hours before the snow began, ^V had the value 15,000. The snow fell for 

 about an hour; and during that time JN'' increased to 55,000. In the evening 

 of the same day there was another faU during which the value 54,000 was 

 obtained, diminishing to 18,000 when the snow ceased falling. 



The following variation was observed eight times during warm, cloud- 

 less weather. The values of N fin ring the day — that is, at different times 

 before 6 p.m. on these occasions — were between 5,000 and 11,000. Between 



