Water will boil at one degree less for every five hundred feet we ascend.
How high is the city of Quito, in South America?
Quito is nine thousand feet above the level of the sea.
At what temperature does water boil there?
Water boils, in Quito, at a temperature of one hundred and ninety-four degrees.
Will an egg boil hard at Quito?
No; because the water passes off into steam at one hundred and ninety-four degrees, and it requires more than one hundred and ninety-four degrees of heat to boil an egg hard.
Do persons, while ascending mountains, often have difficulty in cooking their food?
They do, on account of water boiling there at a temperature below two hundred and twelve degrees.
What is a vacuum?