606 



Sir James Dewar 



[Jan. 1' 



above the centre of the container. A brass sphere was pierced and 

 fixed on the lower end of the spiral lead tube, its weight being- 

 supported bj a light brass chain secured at the joint to the fixed de- 

 livery tube. With a pure lead tube of 8 mm. diameter and Ij mm. 

 bore the weight of the sphere was about loS grams. The two spirals 

 were both wound about the axis formed by the brass chain. The 



lOCfL 



OxvcEN Percentage. 

 in Vapour 



0% 10% 205: 307, 40°/ 507o 607. 707. 607. 907. 100% 



Oxygen Pe.rcentace m Liquid 



Fig. 10. 



inner spiral was carried down only three or four turns, then brought 

 up to form the outer spiral of nine or ten turns, which decreased in 

 diameter down to the sphere. 



When the rigid vertical delivery tube was deflected 45° the 

 resulting displacement of the sphere at the bottom of the spiral was 

 nearly 10° ; on returning to the vertical the sphere went a few 

 degrees beyond. After several movements the final displacement 



