I must tell you that by this time, Jack had learned to read, and this was now a source of great delight to him. It often happened that he could not go into the fields to study nature, because the weather was stormy, or perhaps it was winter, and the ground was covered with snow. It is true that his aunt Piper was generally ready to answer his questions, and to give him information――but she could not attend to him always. Beside, he found in books that there were more exact and scientific accounts of birds, beasts, fishes, insects and other things which interested him, than even aunt Betsey Piper could give. Thus, Jack devoted a good deal of his time to reading, though he did not lay aside his habit of observing and investigating. This habit is very important, and I advise all my young friends to adopt, and continue it, however much they may read. Reading will indeed store the mind, and make it full of knowledge; but observation and investigation render that knowledge clear, distinct, and useful. So, I wish to have every body follow Jack’s plan to read a great deal, and also to investigate a great deal. Thinking is to the mind what exercise is to the body――it makes it strong, cheerful, and full of health. Thus my plan is that reading books and reading nature should go together. Now, I will tell you how Inquisitive Jack managed this. One day, he was going through a little wood, where he saw a squirrel running along upon the fence. It was of a reddish color, and exceedingly nimble. It seemed almost to fly along the rails of the fence, and at last, it mounted upon a tree. It then ran about upon the limbs, and sprang to another tree. Then it dashed from tree to tree almost like a bird, until at last, it reached a large oak. It now seemed to consider itself out of the reach of harm, and accordingly, it began to chatter in the most extraordinary manner. There was something about it that made Jack feel that the fellow was making fun of him. He was annoyed at this, and picking up a stone, he hurled it at the offender with all his force. The squirrel dodged the stone, ran up the tree a little higher, and chattered louder than ever. It seemed to say something like this, “Oh Jack――Jack――you are a very silly fellow――get you gone and leave the woods to me and my companions!――chickaree!――chickaree!――chickaree!” While the squirrel was saying this, he flourished his long red tail, and seemed to be in a state of violent agitation.