After looking at the mills, Forester and Marco walked along up the stream a little way, to look at the mill-pond.  Whenever a dam is made, it causes a pond to be formed above it, more or less extensive, according to the nature of the ground.  In this case there was quite a large pond, formed by the accumulation of the water above the dam.  The pond was not very wide, but it extended more than a mile up the stream.  The banks were picturesque and beautiful, being overhung with trees in some places, and in others presenting verdant slopes, down to the water’s edge.

“That’s a good pond to go a-fishing in,” said Marco.

“Yes,” said Forester, “and it makes fine skating ground in the winter.”

Marco and Forester followed the banks of the mill-pond, until they came to the end of the still water; beyond that they saw a rapid running stream, coming down from the mountains.  Marco wished to follow this stream up farther, to see what they would come to, and Forester consented.  The ground ascended more and more the farther they proceeded, and the view began to be shut in by forests, precipices and mountains.  Marco liked clambering over the rocks, and he found a great deal to interest him at every step of the way.  He saw several squirrels and one rabbit.  He wanted Forester to get him a gun and let him come out into those woods a-gunning.

“No,” said Forester.

“Why not?” asked Marco.

“That is dangerous amusement.”

“Why?  Do you think I should get killed with my sun?” asked Marco.

“No,” replied Forester, “I don’t think you would; but you might get killed.  The risk would be too great for the benefit.”

“Why, you told me the other day, that it was a great thing to learn to take risks coolly.  If I had a gun I could practice and learn.”

“Yes,” said Forester, “it is well to take risks coolly, when the advantage is sufficient to justify it.  For instance, when you crept down upon the pole the other day, to get the reins, you took a great risk, but perhaps you saved the lives of the passengers by it.  That was right—­but to hazard your life, for the sake of the pleasure of shooting a squirrel, is not wise.”  Marco had before this time told him about his getting the reins.

“I shouldn’t think, there was much danger,” said Marco.

“No,” said Forester, “there’s very little danger.  In using a gun, you put yourself in a very little danger of a very great calamity.  There’s very little probability that your gun would burst, or that you would ever shoot accidentally any other person;—­very little indeed.  But if the gun were to burst, and blow off one of your arms, or put out your eyes, or if you were to shoot another boy, the calamity would be a very terrible one.  So we call it a great risk.”

“It seems to be a small risk of a great calamity,” said Marco.