070 MR JOHN AITKEN ON THE NUMBER OF DUST PARTICLES IN THE 



Tahle I. — The Number of Dust Particles in the Atmosphere for 1891 — continued. 









«4-( 



















O m 





ci 



jji 







Place. 



Date. 



Hour. 



Number 

 Partich 

 per c.c 



Wind. 



1 ~ 



3 



5 



State of 

 the Air. 



Remarks. 





May 

















Rigi Kulm . 



24 



9 A.M. 



410 



W. 1 



35 







Extremely 

 thick 



In cloud ; snowing. 







12 



462 



W. 0-5 



36 



JJ 



)> 



Fine rain. 







2 P.M. 



454 



>) 



37 



JJ 



jj 



In cloud. 







4 P.M. 



466 



>> 



J) 



JJ 



55 



jj 







7 P.M. 



494 



>) 



36 



jj 



>J 



Passing clouds. 



» 



25 



9 A.M. 



1,225 



S.E. 0-2 



44 



2 



Thickish 



Early morning was fine 

 and cloudless. 









1,625 





42 







Extremely 

 thick 



In cloud. 









1,025 





44 



1 



?j 



Cloud thinning. 









2,450 



E. 0-2 







jj 



In cloud. 









3,250 









jj 



In dense cloud. 









3,450 









u 



jj jj 









1,250 









u 



Clearing. 









700 









Medium 



Cloud passed. 









1,850 



N. 0-2 







Extremely 

 thick 



In cloud. 







10.30 



4,200 









jj 



jj 







12 



440 

 755 



W. 0-5 



38 







jj 



In cloud; lowest average. 

 Highest average. 



VlTZNAtJ . . 





3 P.M. 



583 



W. 1 



50 



4 



Extremely 

 thick 



Raining; taken in down- 

 current. 







4 P.M. 



1,300 



>> 



JJ 



2 



jj • 



Raining ; air coming 

 from the lake. 







5 P.M. 



2,860 



E. 









Raining ; taken on 





June 















steam-boat. 



English 



2 



5 P.M. 



4,700 



W. 0-5 







Thick 



Raining. 



Channel 



July 

















Kixgairloch 



7 



1 P.M. 



308 



W. 0-2 



57 



3 



Very thick 



Raining. 







5 P.M. 



312 



N.W. 0-2 



61-5 



4 5 



Very clear 





jj 



8 



10 A.M. 



132 



N.W. 1 



54-2 



2-2 



Clear 



Clouds very low. 







12 



101 



)! 



54-3 



2-6 



Very clear 



Clouded all over. 







1 P.M. 



115 



N.W. 2 



54 



2-9 



jj 









3 P.M. 



150 



N.W. 1 



53-5 



2-5 



jj 



Clouded all over. 







6.30 p.m. 



140 



N.W. 0-5 



53 



JJ 



jj 



Showers ; air very clear 

 between showers. 



>> 



9 



10 A.M. 



295 



N.W. 2 



55-2 



5-2 



Extremely 

 clear 



Cloud ^. 







12 



3,700 



JJ 



59 



5-8 



Very clear 



Thin cirrus clouds. 







1 P.M. 



3,850 



JJ 



J) 



4-8 



jj 









3.30 p.m. 



7,600 



JJ 



JJ 



6 



jj 









6 P.M. 



3,800 



JJ 



57 



5-8 



jj 



Thin cirrus clouds. 



>' 



10 



10 A.M. 



67 



N.W. 1 



56 



3 



jj 



Clouded all over ; mist 

 low on hills. 







1 P.M. 



255 



JJ 



55-5 



0-5 



Medium 



Slight drizzle. 







4 P.M. 



171 



JJ 



56-8 



3-2 



Clear 



Clouded all over. 







6.30 p.m. 



200 



JJ 



55 



2-8 



jj 



jj jj 



>» 



1] 



10 A.M. 



142 



N.W. 0-5 



59 



5 



Very clear 



Clouded all over ; 

 showers. 







1 P.M. 



1,200 



S.E. 0-5 



58 



4 



jj 



Numbers very variable. 







4 P.M. 



975 



S.E. 0-2 



59-5 



5 



Clear 





