A. By its diameter and thickness of metal.
Q. Which is the better, single or double riveting?
A. Double riveting is from sixteen to twenty per cent stronger than single.
Q. How much grate surface do boiler makers allow per horse power?
A. About two-thirds of a square foot.
Q. Of what use is a mud drum on a boiler, if any?
A. For collecting all the sediment of the boiler.
Q. How often should it be blown out?
A. Three or four times a day.
Q. Of what use is a steam dome on a boiler?