MANUAL FOR ARMY HORSESHOERS. 17 



If the metal is too near the twyer ball the heat is affected by 

 the cold blast. 



To bank a fire, cover thoroughly with the fuel and open the slide 

 below; this will keep the fire alive for several hours. Wlienever 

 the fire is left for more than a few minutes the slide should be left 

 open. 



CLINKERS. 



6. Heated steel or iron gives off particles or scales which remain 

 in the fire. These melting pirticles bind together particles of 

 bui-ned coal, gradually becoming larger and finally forming what 

 is called a clinker. Clinkers give off but little heat and obstruct 

 and spoil the fire; they must therefore be removed as fast as they 

 form. Their presence' will be shown by a tendency of the fire to 

 spread and an unusual throwing out of sparks. If indications of 

 clinkers appear, open up the fire with a poker, and as soon as the 

 air touches the clinker it will turn black and become a solid mass 

 which can be lifted out entire. Tr\dng to drag out the clinker 

 without opening up the fire only results in breakmg up the clinker 

 and making the fire worse than it was before. 



HEATS. 



7. There are four degrees of heat that are to be considered by the 

 horseshoer, and they are generally designated as the black, the 

 cherry red, the ivhite, and the welding or sparking heat. 



The black heat is when the shoe is hot but shows no color, and 

 is used in making minor changes in shaping, leveling, and in open- 

 ing nail holes. 



The cherry red heat is when the steel or iron shows a bright cherry- 

 colored glow. It is used in the general shaping of the shoe, in 

 pointing the pritchel, and in sharpening tools. 



The next degree of heat is called the ichite heat because the steel 

 or iron then shows almost that color. This heat is used when it 

 is necessary that the metal should be very pliable and easily 

 worked, as in drawing toe clips, cutting off the heels, in drawing 

 the heels of the shoe, in hot rasping, and in turning heel calks. 



The welding heat is sometimes called sparking heat for the reason 

 that the metal then gives off small particles which explode or 

 spark above the fire. As soon as the sparks appear watch the 



17722°— 17 2 



