Very neat old manuals from the International Textbook Company of Scranton, PA, copyright 1935 & 1936. Set of 3, including #381 B Boiler Feeding & Flue Gas Analysi, # 457 Boiler Fuels and Trials, #471 Pulverized Coal Burning. Very neat old manuals, in great, readable shape with minor signs of wear on covers. Hardback. I have a good number of these, please email me if you are looking for a specific volume or subject.