If everything were now as it was in 1791, what a queer place this world of ours would be to us!
A hundred years ago!
Suppose we imagine ourselves living in the year 1800.
The railroads then were very few and poor.
"Fulton's Folly," the first steamboat, had not yet frightened the sailors in New York Harbor, with its long line of black smoke.
Lighting by means of gas was yet unknown.
Electric lights were not even dreamed of.
Even kerosene, which we think makes so poor a light, was then unused.
So there are many, many things, common and useful to us now, which were unknown to the world in 1800.
You have heard of the giant, Steam.