This is an essay in which Emerson presents his typically Transcendentalist views on education, arguing against the traditional education system and broadening the term in our thinking to encompass the role that nature and life have as educating forces in our lives. Consider the following quote which contains an analogy which is then developed by Emerson:
The household is a school of power. There, within the door, learn the tragicomedy of human life. Here is the sincere thing, the wondrous composition for which day and night go round. In that routine are the sacred relations, the passions that bind and sever. Here is poverty and all the wisdom its hated necessities can teach, here labor drudges, here affections glow, here the secrets of character are told, the guards of man, the guards of woman, the compensations which, like angels of justice, pay every debt: the opium of custom, whereof all drink and many go mad. Here is Economy, and Glee, and Hospitality, and Ceremony, and Frankness, and Calamity, and Death, and Hope.
Emerson thus argues that the household is our first port of call in our education, and compares it to a "school of power" in the way that we learn so much through our time in our homes and being raised. He lists the various forms of teaching that are available to us in this "school of power," and highlights its importance to our educational development.
Secondly, you might like to think how Emerson paints schools as factories that produce unthinking robots who are unable to relate to society around them with a critical eye:
A rule is so easy that it does not need a man to apply it; an automaton, a machine, can be made to keep a school so. It facilitates labor and thought so much that there is always the temptation in large schools to omit the endless task of meeting the wants of each single mind, and to govern by steam.
Note the references to "automatons" and "machines." This second analogy is of course central to Emerson's argument as he attacks the school system and what it is producing.