668 



Mil JOHN AITKEN ON THE NUMBER OF DUST PARTICLES IN THE 



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













c3 



_tj> 







Place. 



I 'ate. 



Hour. 



Number 



Particle 



per c.c 



Wind. 



Oh ;-. 



"a 



State of 

 the Air. 



Remarks. 





May 

















Baveno . . 



6 



9 A.M. 



3,100 



S.E. 0-2 



67 



7 



Medium 









2 P.M. 



3,050 



)> 



)) 



>) 



>> 





>> 



7 



8.30 a.m. 



3,000 



)> 



65 



10 



Hazy 



Distant mountain clear ; 

 hazed low down. 







12 



4,450 



E. 1 



63-5 



6-5 



Thick 



Air rapidly thickening. 







2 



4,100 



E. 0-5 



62 



5 



Very thick 



Air still thickening. 







4 



3,750 



S.E. 0-2 



■)■) 



)) 



)» 



Slight rain. 







5.30 



2,800 



E. 0-2 



60 



)> 



)> 



)> 



>» 



8 



11 A.M. 



800 



N.W. 1-5 



56 



J) 



1 



Passing showers. 







4 P.M. 



775 



N.W. 2 



52-5 



1-5 



Extremely 

 thick 



Raining heavy. 



>) 



9 



12 



1,300 



Calm 



52 



1 



n 



>» >) 







5 P.M. 



3,600 



N.W. 0-5 



54 



1-5 



j> 



j) n 



>» 



10 



9 A.M. 



2,500 



S.E. 0-2 



56 



5 



Hazy 



Tops of mountains clear ; 

 haze low down. 



)> 



11 



12 



6,400 



Calm 



62-5 



8 



I? 



Clear high up ; hazed 

 low down. 







3.30 p.m. 



3,700 



S. 0-2 



58-5 



5 



>) 



On hill-side 400 feet up. 







4.30 p.m. 



2,950 



>) 



60 



5-5 



)> 



On hill-side 800 feet up. 



>i 



12 



12 



3,700 



S.E. 0-2 



68 



11 



Medium 



At lake-side. 







3 P.M. 



3,900 



J? 



72 



10 



») 



On hill-side 500 feet up. 







3.30 p.m. 



2,900 



!! 



69-5 



11-5 



»j 



On hill-side 1000 feet 

 up. 



it 



13 



12 



6,700 



Calm 



68 



9 



)> 



Probably too high from 

 local pollution. 







3 P.M. 



3,800 



>> 



67 



8 



>) 



On hill-side 1000 feet up; 

 air from mountains. 







4.30 p.m. 



1,900 



)> 



68 



11 



>» 



On hill-side 1800 feet 

 up ; passing shower. 



» 



14 



3 p.m. 



6,600 



N.W. 0-2 



76 



15 



)> 



On hill-side 500 feet up. 







4 P.M. 



4,000 



)? 



74 



14 



)> 



On hill-side 1000 feet 

 up ; air from lake. 







4.30 p.m. 



4,000 



)) 



72 



13 5 



)> 



On hill-side 1200 feet 

 up ; air from lake. 







5.30 p.m. 



5,000 



S.E. 0-2 



70 



10 



)j 



At lake-side. 



>) 



15 



11.30 a.m. 



4,200 



S.E. 0'5 



66-5 



7-5 



Thickish 

 haze 



At level of lake. 







3 p.m. 



3,150 



Calm 



62 



3 



)! 



500 feet up ; been rain- 







3.30 p.m. 



3,200 



S.E. 0-2 



60-5 



35 



)7 



ing. 

 1000 feet up; thunder 

 and some rain. 







4 P.M. 



2,400 



S.E. 



56-5 



35 



J) 



1600 „ 







4.30 p.m. 



1,350 



Calm 



56 



3 



)) 



1800 „ 



>» 



1G 



9 A.M. 

 1 P.M. 



1,950 

 2,500 



S.E. 0-2 



N. 2 



65 



5 



Thick 



At level of lake ; 



thunder. 

 On steam-boat crossing 



to Laveno. 







3 P.M. 



300 



N. 4 







Clear 



On lake above Luino; 

 raining. 







3 P.M. 



450 



>> 





... 



>) 



Snowing on mountains. 



LOCAKNO . . 



1G 



5.30 



550 



E. 4 



53-5 



8-5 



Very clear 



On lake-side ; snow 

 down to within 2000 



















feet of lake. 



