CHAPTER I

STEAM, HEAT, COMBUSTION, AND FUELS

Ques. 1.-What is steam?

Ans.-Steam is vapor of water.

Ques. 2.-At what temperature will water evaporate (boil) in the open air at sea level?

Ans.-212 degrees Fahrenheit.

Ques. 3.-If 1 cubic foot of water is evaporated at 212 degrees into steam at atmospheric pressure, how many cubic feet of steam will there be? In other words, what will the volume of the steam be?

Ques. 4.-Then what is the relative volume of steam at atmospheric pressure, and the water from which it was evaporated at 212 degrees?

Ans.-1,646 to 1.

Ques. 5.-What is the relative volume of steam at 200 pounds gauge pressure, and the water from which it was generated?

Ans.-132 to 1.

Ques. 6.-What is meant by the terms atmospheric pressure, gauge pressure, and absolute pressure, as applied to steam and other gases?

Ans. The pressure in pounds exerted by the steam, or gas, on each square inch of the interior surface of the containing vessel, tending to rupture it.

Ques. 7.-What is vacuum?

Ans.-The absence of all pressure in the interior of a

vessel.

Table 1, which follows, shows the physical properties of saturated steam from a perfect vacuum up to 1,000 pounds absolute pressure. It will be found convenient for reference.