Nov. '99, p. 78, the author did not mean to imply the words air and oxygen were interchangable. An excess amount of combustion air contains nitrogen and oxygen. Unnecessarily heating both gases reduces overall boiler efficiency. Also, the text following the second bullet, p.79, should have read, "Operators feel more comfortable when a boiler operates in an air-rich condition." Fuel-rich conditions can lead to a "kaboom." Air-rich boilers waste money. These corrections were also made to the online version of this article at www.controleng.com.

mid-Dec. '99, p. 94. The company is located in Flushing, Mich.