2 Burgess, Sowe Convection Effects in a Heated Tube. 

 This is seen in Fio. i. 



Fiz. I. 



Fis:. 2. 



This indicated that the effect was due to heating, the 

 centre of the tube being hotter than the walls, which were 

 cooled by the air. 



With a strong current it was possible to see the hot 

 coloured liquid rise in the centre, and spread out into a 

 mushroom shape. The cold liquid from the walls falling 

 underneath broke off the head of the column, giving a 

 new layer. 



Water coloured by a dye was then placed at the 

 bottom of a vertical tube, with plain water above. 



A platinum wire enclosed in a thin glass tube was 

 inserted down the centre. 



