LOWRY. 



Phil. Mag. Ser. 6, Vol. 28, PL IX. 



(a) " Combined " gas. 

 64 feet. 



(b) " Combined " gas. 

 15 feet. 



('■) NO. T ^ n . 



« *°-2 Wbo- 



(«) NO*^ 



( /*) Copper arc. 



