ON PLATE-CASTING. 21 



This has been burnished on a hard plaster-and- 

 sand model. 



" No. 5. The same piece cast on a plaster-and- 

 sand model as a core, showing a well-defined 

 internal surface. 



" No. 6. A plate cast from a scraped model, 

 with wax plate and plaster model. 



" No. 7. Lower piece in the rough state, with 

 wax and plaster models. 



" The aforementioned are in silver. 



" No. 8. Strip of 18-carat cast gold. 



"Also, specimens of casting sand, and of the 

 thin sheet- wax used.* 



" The gold casting is now in my mouth, and I 

 am happy to say that, after a month's wear, and 

 although only roughly fitted in before a mirror, 

 I have found it from the first as comfortable as 

 an ivory piece, and more so than one in gold 

 made in the usual way, resting firmly in its place, 

 without springing or annoying the remaining 

 teeth. The strip No. 8 is part of the same plate 

 (cut off to reduce its size, and leave as Httle in 

 the mouth as possible consistent with strength). 

 One end has been struck between zinc and lead, 

 and the result shows increased hardness and con- 

 sequent capability of receiving a higher polish ; 

 but I am not prepared to say that it would be 



* This is the white wax employed for making artificial flowers, and 

 was procured from Mrs. Peachy and from Mr. Kcenig, of Rathbone 

 Place. 



