68(5 



MR JOHN AITKEN ON THE NUMBER OF DUST PARTICLES IN THE 



Table III. — The Number of Dust Particles in the Atmosphere for 1893 — continued. 









CM 



O cc 





ot 



>> 







Place. 



Date. 



Hour. 



Number 



Particle 



per c.c. 



Wind. 



P-l H 



a 3 



<x> 

 EH 



-4-i 



1 



3 



w 



State of 

 the Air. 



Remarks. 





May 

















Rigi Kulm . 



13 



9 A.M. 



2,975 



E.S.E. 1 



38 



4 



Clear 



(E. 70, W. 250). 







11 A.M. 



13,250 



>» 



40 



2-5 



>j 



Nearly cloudless above, 

 but low down nearly 

 covered. 







12 



15,750 



E. 1 



39 



1-5 



Medium 



(E. 45). Clouds tend- 

 ing to form on Rigi. 







1 P.M. 



16,500 



>) 



41 



4 



j> 









3 P.M. 



10,875 



E. 0-5 



JJ 



>> 



>) 



(E. 50). 







5 P.M. 



11,250 



N.E. 1 



43 



6-5 



j) 



(E. 50, W. thick haze). 







7 P.M. 



4,035 



E.N.E. 1 



40 



6 



?> 



(E.50, thick haze to W.), 

 cloudless. 







7.30 p.m. 



3,300 



)> 



)> 



)) 



)> 



Hochgerrach not seen 

 siuce 7 a.m. 



>> 



14 



6 a.m. 



1,250 



S.E. 0-2 



44-5 



6-5 



Clear 



Cloudless. 







7 A.M. 



1,100 



S. 0-5 



45 



8-5 



>) 



(E. 100, W. 120). 







8 A.M. 



1,375 



S.W. 0-5 



48 



8 



>> 



3) 







9 A.M. 



1,375 



S.W. 1 



49 



»> 



j> 



)) 







11 A.M. 



1,625 



)> 



52-5 



8-5 



>) 



(E. 80, W. 180). 







1 P.M. 



1,725 



Variable 



51 



8 



j» 



(E. 80, W. 100). 







3 P.M. 



3,325 



jj 



50 



7 



jj 



(E. 80, W. 80). 







5 P.M. 



1,750 



>) 



>> 



7-5 



jj 



(E. 70, W. 60). 







7 P.M. 



1,825 



J! 



48 



6-5 



jj 



(E. 80, W. 60). Cloud- 

 less all day. 







7.30 p.m. 



1,875 



S.E. 0-2 







jj 





)> 



15 



7 A.M. 



925 



S. 1 



49 



7-5 



jj 



(E.90.W.180). Cloudless. 







9 A.M. 



1,375 



S. 0-5 



48 



6-5 



» 



(E. 100, W. 100). Thin 

 haze over sky. 







11 A.M. 



2,150 



N.E. 0-2 



52-5 



4-5 



Medium 



(E. 60, W. 50). Clouds 

 becoming denser. 







12 



2,700 



N. 0-5 



47-5 



2-5 



jj 



Air still getting thicker. 







1 P.M. 



4,405 



N. 1 



48 



H 



Thickish 



No distant mountains 

 visible. 







3 P.M. 



3,900 



N.W. 1 



45 



2 



)) 



Clouds beginning to 

 form on Rigi. 







5 P.M. 



2,650 



N.W. 05 



42 



jj 



Thick 



Clouded all over. 







7 P.M. 



2,800 



N.W. 0-2 



41-5 



>j 



Very thick 



Been slight rain. 







9 P.M. 



2,650 



S.W. 0-2 







» 



Light rain. 



»> 



16 



7 A.M. 



1,225 



N. 0-2 



42 



2 



Medium 



(40). Cloudy morning. 







9 A.M. 



1,275 



)» 



43 







jj 



Thin cloud just passed 

 over top of Rigi. 







10.30 A.M. 



2,050 



W. 0-2 



48-5 



2-5 



jj 









11 A.M. 



2,600 



S.W. 0-5 



51 



>» 











12 



2,650 



S.W. 0-2 



52 



3 



Thickish 



(30). Clouded over. 







1 P.M. 



2,650 



)> 



)! 



i) 



j> 





VlTZNAU . . 





2.30 p.m. 



5,400 



JJ 



69 



10-5 



Medium 



Clouds passing away. 







3 P.M. 



5,100 



)J 



67 



10 



jj 



Two miles up the lake 

 from Vitznau. 







3.30 p.m. 



5,300 



•>•> 



69 



11 



jj 



One mile from Vitznau. 



English 



20 



1 P.M. 



8,500 



S. W. 0-5 









Dull ; observed near 



Channel 







6,000 

 3,800 



J! 

 JJ 









French coast. 

 Air coming off French 

 coast. 



