Production of Sections 



269 



basin upon a piece of cold metal, when the lower stratum 

 of wax will rapidly harden sufficiently to support the 

 object, even should it be a pyramid standing on its apex. 



FIG. 73. PARAFFIN COOLED RAPIDLY. ( x 250 Diameters.) 

 Very small crystals. 



Immediately on placing the basin upon the cold metal, keep 

 the object moving with a heated needle, so that it does not 



' ' . \ 





FIG. 74. PARAFFIN WAX COOLED SLOWLY. 

 Observe large crystals. 



( x 250 Diameters. ) 



stick in the wrong direction to the cooling paraffin at the 

 bottom. In a few seconds it will be found that the object 

 will stand in any position in which it is placed. When 



