Ferguson and Merivin — The Ternary System. 89 



silica could be identified, but in the milky glasses the par- 

 ticles causing the milkiness could not be identified micro- 

 scopically. In the charges very rich in silica this 

 tendency to crystallize was accompanied by a great vis- 

 cosity, so that relatively large crystals of cristobalite, 



Fig. 





Very Ti/iz Plcdmum. Uzre , 



PlaHnum. Foi Z 



Fig. 7. — The quenching apparatus and furnace. (1) The furnace set 

 up; (2) Enlarged views of parts of the quenching apparatus showing the 

 method of insulating leads, etc., and the method of attaching the charge; 

 (3) a longitudinal section of the device used to carry the copper leads by 

 means of which a heavy current could be sent through the platinum leads 

 to which the charge is attached and thus cause the charge to fall by fusing 

 the supporting fine platinum wire. When this operation is to take place, 

 the support block and transite cap are removed and a dish containing mer- 

 cury is inserted beneath the marquardt porcelain tube in order to catch 

 the charge and chill it instantly. 



