44 



MR JOHN AITKEN ON THE NUMBER OF DUST PARTICLES IN THE 



Table of the Number of Dust Particles in the Atmosphere — continued. 



Place. 



Date. 



Hour. 



mber of 

 irticles 

 er c.c. 



Wind. 



ft £ 



2 5 



3 



State of 

 the Air. 



Remarks. 













H 













April 

















Bellagio . . 



25 



11 A.M. 



7,600 



S. 0-2 



53 



5 



Thick 



Limit of visibility 1 5 miles N. 







4.30 p.m. 



4,100 



)> 



52 



3 



Very thick 



Air thicker than in morning. 



>) 



26 



12 A.M. 



1,150 



N. 5 



48 



4 



Clear 









5.15 p.m. 



900 



)» 



47 



6 



Very clear 



Air getting clearer. 



>) 



28 



11 A.M. 



10,250 



? 



55 



7-5 



Clear 



Too high from local impuri- 

 ties,due to absence of wind. 



!) 



29 



10 A.M. 



900 



N. 3 



60 



15 



Very clear 



Ahnost no haze through 15 

 miles N., and only a little 

 through 15 miles S. 







11 A.M, 



600 



N. 2 



61 



15-5 



Extremely 

 clear 





)) 



30 



10 A.M. 



20,500 



S. 0-2 



55 



7 



Thick haze 



Too high from local pollution. 



Limit of visibility 1 5 miles 



S. 

 Taken in boat on Lake. Be- 







11 A.M. 



5,200 



i) 



52 



4 



Thick 





May 















ginning to rain. 



Baveno . . 



3 



10 A.M. 



7,700 



E. 0-2 



64 



9 



Thickish 

 haze 









11 A.M. 



10,750 



>j 



54 



4 



)) 



Taken in boat on Lake. 







3 P.M. 



1,750 



E. 2 



61 



9 



Medium 



Taken on land. 



Simplon Pass 



5 



4.30 p.m. 



6,000 



S.E. 0-5 



54 



1 





Rain just ceasing. 



Baveno . . 





6 P.M. 



7,800 



S.E. 0-2 



54-5 



5-5 





Taken at Baveno. 



>) 



6 



10.30 A.M. 

 12 A.M. 



16,000 

 14,125 



S.E. 0-1 



62 



10 





Probably local impurities. 

 Taken in boat on Lake. 







3 P.M. 



4,200 



S.E. 2 



62 



10 





Increase of wind, reduction 

 of dust. 



Simplon Pass 



7 



4 P.M. 



2,010 



W. 3 



52 



2 



Thick 





Baveno . . 



9 



11 A.M. 



5,400 



N.E. 0-2 



63 



7 



Hazy 



Wind inshore. 







11.30 A.M. 



5,100 



)5 



60 



>? 



)> 



Taken in boat on Lake. 







12 A.M. 



4,100 



S.E. 0^3 



61 



5) 



)> 



Taken on shore. 







12.30 p.m. 



2,600 



S.E. 1 



)? 



II 



>» 



Wind increasing. 



Locarno . . 



13 



5 P.M. 



4,500 



1 



56 



2? 



Thickish 



Raining, wind slight and 

 variable. 



Lucerne . . 



14 



6 P.M. 



4,000 



1 



53 



2 1 



Thick 



Been raining, wind slight. 



VlTZNAU . 



15 



2.45 p.m. 



11,080 



S. 0-2 



64 



10 



Thick haze 



Hills thickly veiled in haze. 



RlGI KULM . 



I 5 



4.45 p.m. 



3,400 



N.E. 0-2 



44 



2 



Thickish 



Air extremely thick looking 

 downwards, and thickish 

 at level. 







5.30 p.m. 



4,100 



E. 0-2 



41 



2 



)) 









6 P.M. 



4,200 



N. 0'2 



>) 



j) 



»> 





)) 



16 



9 A.M. 



1,500 



S.E. 0-5 



52 



5 



Hazy 









9.30 a.m. 



1,150 



)? 



)J 



6 



?! 









10.30 A.M. 



1,325 



» 



55 



8 



>) 









3.30 p.m. 



6,600 



)5 



50-5 



4 



Thick haze 



Increase in dust, probably due 

 to lower air rising. 







5.30 p.m. 



6,700 



J) 



49 



4-5 



)> 





>> 



17 



9 A.M. 



2,100 



1,950 

 1,200 



E. 0-5 



52 



6 



Thickish 

 haze 



!) 

 )) 



Wind variable, changing from 

 S. of E. to N. of E. 



