Now they were sitting just in front of the house under a large tree, and the father said, “I will put you all to the test, and see what you can do.” Then he looked up and said to his second son, “Between two branches up at the top of this tree, there is a chaffinch’s nest, tell me how many eggs there are in it?”

The astronomer took his glass, looked up, and said, “There are five.”