678 



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



TABLE II. — The Number of Dust Particles in the Atmosphere for 1892 — continued. 









&4-I 



















O <zi . 





ci 



>> 







Place. 



Date. 



Hour. 



Number 



Parti ck 



per c.c 



Wind. 





-3 



a 



s 



K 



State of 

 the Air. 



Remarks. 





May 

















RlGI K.UI.M . 



20 



8 A.M. 



3,150 



W.N.W.0-5 



40-5 



3 



Medium 



Sky clear at sunrise, 

 now clouded over. 







9 A.M. 



5,800 



W.N.W. 1 



41 



1-5 





Air from Lucerne. 







10 A.M. 



5,433 



JJ 



42 



1-8 





>> 







12 



13,750 



JJ 



46-5 



3 



Thickish 



)) 







2 P.M. 



5,500 



N.W. 2 



47 



6 



? ? 









3 P.M. 



5,600 



>> 



M 



)) 



n 









4 P.M. 



3,900 



!> 



45 



5 



jj 









6 P.M. 



2,500 



5) 



>! 



)) 



?j 



Jura visible all day, 

 clouded afternoon. 







7 P.M. 



2,550 



W. 3 







jj 





>> 



21 



8 A.M. 



9.5 A.M. 

 9.10 A.M. 

 9.15 A.M. 



925 



900 

 1,775 

 3,750 



W.N.W. 4 



JJ 

 J> 

 JJ 



35-5 







In cloud 



jj 

 jj 

 jj 



In dense cloud and 

 slight rain. 







9.30 a.m. 



4,000 



JJ 



36-8 



0-5 



jj 









9.40 a.m. 



7,700 



)) 







jj 



In dense cloud. 







10.15 a.m. 



3,000 



JJ 



37 



0-2 



jj 



In thin cloud. 







10.25 a.m. 



1,500 



)5 







jj 









10.30 A.M. 



1,100 



JJ 



38 



0-5 



jj 



In thin cloud. 







10.45 a.m. 



4,600 



J> 



37-2 



0-2 



? 



Clouds above Rigi 

 Kulm. 







12 



3,275 



N.W. 2 



41 



1-8 



Medium 



Clouds some height 

 above mountain. 







2 P.M. 



2,825 



J J 



42 



4-5 



jj 



Cloud and sunshine. 







4 P.M. 



7,650 



N.W. 1 



41 



3 



Very thick 



Lower part of Pilatus 

 scarcely visible. 







6 P.M. 



3,425 



N. 0-5 



38 



2 



jj 









7 P.M. 



4,600 













!> 



22 



7.30 a.m. 



1,000 



W. 0-5 









Cloudless ; very thick 

 E., thick N. 







8 A.M. 



1,375 



!> 



38 



2 



Thickish to 

 thick 



Very clear, high to S.W. 







9 A.M. 



1,950 



>> 















10 A.M. 



4,125 



S. 0-5 



46 



- 5-5 



Medium 



Cloudless. 







12 



7,400 



S.W. 0-5 



49 



5 



ji 



Cloudless ; clear high up. 







12.30 p.m. 



3,650 











Cloudless. 







2 p.m. 



4,675 



W. 0-2 



51 



5-5 





)> 







4 P.M. 



3,275 



JJ 



)J 



4-5 



Thickish 



>) 







G P.M. 



4,400 



Variable 



45 



3-5 



Thick 



5) 







G.30 p.m. 



2,750 



)) 







)> 



Cloudless all day but 

 Hochgerrach was 

 never visible. 







7 P.M. 



2,150 



)j 







j? 





>) 



23 



7.30 a.m. 



1,425 



S. 0-2 



50 



6 



Medium 



Clearest morning ob- 

 served this year. 







8 A..M. 



1,412 



JJ 



53 



7 



ji 



Hochgerrach just visible. 







10 A.M. 



1,350 



N. 0-2 



■>•> 



5) 



)> 









12 



1,350 



W. 1 



44-5 



0-5 



In cloud 



Raining. 







2 P.M. 



1,200 



)» 



43 







Very thick 



Close drifting rain. 







4 P.M. 



1,025 



tj 



42 



1 



i) 



)> 







G P.M. 



671 



n 



41 



JJ 



15 



i) 



