FROST NAILS AND STUBS. 



155 



Delperier invented a special form of nail now largely used 

 in France, to prevent slipping on smooth granite ' setts ' and 



.^ — 



Frost nails. 



Fig. 105. 



Frost stubs. 



also on frozen macadamised roads. It is simple, durable, and 

 effective. 



The nail consists of a head, neck, and shank. The head is 

 cubical, this form having been found more durable and gener- 

 ally useful than the pointed or wedge heads. The wearing 

 surface presents two deep cuts dividing it into four parts, and 



Fig. 106.— Del perier's frost nail. 



improving its holding power on the roadway. The head is 

 of the same height as the web of the shoe to which the nail is 

 attached. Experience .shows that this is more than sufficient 

 to wear for one day. The neck and shank are relatively very 

 short and stout. 



