560 



MR A. J. HERBERTSON ON 



! 

 1 



fllf 



es J 2- 



+ >P i 



CM »0 CO Cl CO Cl 



CM Cl <M (N CM (M 



"8 



P5 

 O 



% 



> 



en 

 n 

 O 



a 

 > 



O 



s 



o 



Dust particles per 

 cubic centimetre. 



00 CM eo lO 

 CM OS OS CO 



CO 



o 



o 



o 



\a 



co 



<M 



lO 



CO 



-* 



>^ 



OS 



CO 



eo 





*o 



CO 



CI 



CO 







O o, 



r-ICO^OOOSOOOOOSOS 



in co eo 



CM CO CO CO 



sassssssssssssss 



333333*3333333333 



oooooooooooooooo 



OOOOoOOO 





ci ,H c, =? ^ 



t»> >> rH '" H t>> g 



^ ^ ^ I" ^ I 



tO 91 !8 ? to O 



° rH 



I <^ 



55 |2J 



£ £ fc 



£ 5q 55 55 



55 



CN CM 



55 55 



55 O 



W &q •£ fe: ^ 

 55 fe & co co 



l^ O CO 00 OS 

 r-H CM CO CO O 



CO lO CO CO 00 00 CO 

 OS VO 00 <N <N O O 



CO lO lO lO 



oo^*-*osososoo 



lOiOlOlOlOiCSlOCOCO 



t*- 1^ w w t-- 1>- 1-^ c^ t- 



^* m wo o o 



CO CO CO t^ t^ 



Mass of Vapour per 



cubic metre of Air 



(grammes). 



r-COOSOcOCO*a-rJHCO*<* 

 COOSOOCOOOCMCOICICOCO 



lO lO CO CO 



0O CO lO CO OS CM CO 

 00 O r-l CO CO OS OS 



OS OS CO oo 



N ® (D 1Q (O lO 



lO CO CO CO **- CO CO 



o 



OS 



CO 



CO 



o 



CO 

 OS 



CM 



CO 



co 



o 



lO. 



1Q 



CO 

 Cl 



CO 

 CI 



eo 



Cl 



r-i 

 Cl 



Cl 



Cl 

 Cl 



Cl 



Cl 



CO 

 CM 



CO CO rH CO to CO 



t-I -<* CO tO 



« o .s &: 



Ph 





'& 



o 



a 



CD 







rt 



H 









CD 









s 



ofl 



h 



T) 



3 





P-) 



CJ 



O 







r^ 



> 









CO 

 00 



CN 



CO 



1— 1 



CN 



o 

 CM 



CO 



as 



CM 



00 



1— 1 



CO 



o 



Cl 



1^ 



Cl 

 Cl 



CO 



m 



CM 



CO 



OS 

 OS 



CO 



o 



cs 



OS 



o 



CM 



OS 



OS 

 1 r-l 



CM 



^tl 



OS 



o 



1 t- 



CM 



CM 



I— 1 



CO 

 CO 



OS 

 Cl 

 CM 



CO 

 CO 



CM 



CM 



CO 



oo 



CO 

 CO 



CO 



co 



CO 

 00 



CO 

 00 



CD 



oo 



CO 



oo 



eo 



CO 



CD 

 00 



CO 

 CO 



CD 



00 



CO 

 00 



CO 

 CO 



CO 



oo 



CO 



1 y 



CO 

 00 



CO 



1 " 



CO 

 OO 



CO 



OO 



CD 



CO 



CO 



oo 



eo 



CO 



CD 

 CO 



COCOCOCOCOCOCOCOCOCOCOCOCOCO 

 CM Cl Cl c-1 CM CM CM CM Cl Cl CM CM CM CM 



CO CO CO CO CO CO CO 

 CM CM CM CM 



3 



ca 



O d> 



so 3 

 <3 >> 



i— ■ io Oi co oo 



tO CO CO OS 



<N CN >1 <N 



CM OO CO 



CO CO t-H tN CD CM CD 



co m cn to co co co 



CO tO CO 





O ^h o o 



CM CO (M 



O i-i CN 



f-> O r-l lO »-l O i-H 



o o o 



o o o o 





lO O CN CO 05 CO CO 



—« 0O rH -rri 00 CO l>- 



t-- lO lO r- 1 <N OO CO 



(N CN CN C-1 CM rH <-H 



1^ CD N N W N M m 



CD CT> t— CN l>- t^ i-l Z. 



k^. l^. lO lO t— * CO CO ^ 



i— I ,— i .— t ,— I rH rH »-H t; 



t^ CD CM CD 



CO lO CN -^ CO CO CO 



CS CO w ■* 



CO lO CD 



CO O CO 



CNtO-^tOCOCOtOCOtOOi 



"^ iO tO CN CD ■* 



tOiTiCNOii>-f-iOi— t Tji rH OO CO 



CN OO H ■* N 



(N CO lO 



C?1 -* Ol (M M Cl Cl (N 71 



CO ■** CO 



i— I CN CO CO 



CD CO CN CN CN 



t* CD CD 



Oi)— IO)COOOCD^O-*OiNNCOiO 



CN OS O CO 



CN CN C7S O CO CM 



lO O CO 



i-HrHi— ICNCNOS^LQ 



at 



C 



T) . 





3 « 





a ■« 



CO 



3 .S 





^ —1 





w s 









jS 



Cl 



Q 





id 

 1 



10 

 1 



IS 



eo 



M 

 1 



S 



o 



1 



OS 



CM 



1 



eb 

 1 



To 

 1 



o 

 n 



oo 



1 



o 



CO 



1 



o 



1 



o 



S 



o 



CO 



-^ 



Cl 

 CM 



i— i 



o 



■* 



CM 



J5 



r- 



o 



eo 



CO 



m 



t-H 



Cl 



CO 



1^ 



00 



9 



SO 



1 



oo 

 1 



1 



Q 



CM 



-V 



1 



o 

 CO 



1 



1 



o 





O 



CO 



CO 



CO 

 CM 



m 



Cl 



CO 



■* 



id 



CO 



en 



°0 1^ CO OS 



r-l CM CM 

 CO OS OS 



OS J 



00 pa 



if. CO 1- os o> 



co co co co eo 



n » <i a (o 

 t^ »^ t^ i>- t^ 



COOSOr-<CMCO"*lC5e0 1^000S 

 l^l^OOCOOOOOOOOOOOOOOOOO 



