LEAD PENCILS 165 



A soft pencil has more graphite and less clay than a hard 

 pencil. The hard pencil was also baked with greater heat. Show 

 the use of the hard and soft pencil, and what is a good and a bad 

 pencil. Sometimes fine graphite is sawed into leads without going 

 thru the process of mixing with clay. 



Graphite is carbon, the same substance as charcoal, coal, 

 and diamond. It is mined in the United States and England. 



Other uses of graphite are as a lubricant, as stove polish, as 

 crucibles. Illustrate and bring out the properties which make it 

 useful in each of these cases. ' 



The wood of the best pencils is cedar, which is almost wholly 

 derived from the swamps of Florida. 



