259
In steam, determination of 129
Mud drum of Babcock & Wilcox boiler 51
Napier's formula for flow of steam 321
Natural gas, burners for 229
Combustion of 229
Composition and heat value of 229
Nitrate of silver in testing feed water 105
Nitrogen, as indication of excess air 157
In air 147
In flue gases 157
Nodules, fire brick, ratio of 303
Size of 303
Normal reading, throttling calorimeter 131
Nozzles, steam sampling for calorimeter 134
Location of 134
Oil fuel, burners (see Burners).
Capacity with 224
Combustion of 217
Comparison with coal 214
Composition and heat value of 213
Efficiency with 224
Furnaces for 221
Gravity of 214
In combination with other fuels 224
Stacks for 251
Tests with 224
Open hearth furnace, Babcock & Wilcox boiler set
for utilizing waste heat from 236
Open heaters, feed water 111
Operation of boilers 291
Optical pyrometers 91
Orsat apparatus 160
Oxalate of soda in feed water treatment 106
Oxygen in air 147
Flue gases 155
Peabody draft gauge 255
Formulae for coal calorimeter corr