It becomes tougher or stronger as it is heated, till it
reaches a temperature Of 550 degrees when it rapidly
decreases its power of resistance as it is heated beyond this
temperature.
Q. How do you account for this?
A. Because after you pass the maximum temperature
of 550 degrees, the more you raise the temperature the nearer
you approach its fusing point when its tenacity or resisting
power is nothing.
Q. What is the degree of heat necessary to fuse iron?
A. 2912 degrees.
Q. Steel?
A. 2532 degrees.
Q. What class of boilers are generally used in a threshing
engine?
A. The flue boiler and the tubular boiler.
Q. About what amount of heating and grate surface is
required per horse power in a flue boiler.
A. About 15 square feet of heating surface and 3/4 square
feet of grate surface.
Q. What would you consider a fair evaporation in a flue
boiler?
A. Six pounds of water to I pound of coal.
Q. How do these dimensions compare in a tubular boiler.
A. A tubular boiler will require I/4 less grate surface, and
will evaporate about 8 pounds of water to I pound of coal.
Pages:
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148