But when the average farmer learns to transmute compost into grass and grain, and these into beef, he usually stops, content. To be a scientist in the true sense, one must love knowledge for its own sake, and not merely for what it will bring on market-day, and so the Humboldts were led on through the stage of wanting to make money, to the stage of wanting to know the why and wherefore. It will be seen that the education of the Humboldts was what the Boylston Professor of English at Harvard calls "faddism, or the successful effort at flabbiness." Our Harvard friend thinks that education should be a discipline--that it should be difficult and vexatious, and that happiness, spontaneity and exuberance are the antitheses and the foes of learning. To him grim earnestness, silence, sweat and lamp-smoke are preferable to sunshine and joyous, useful work so wisely directed that the pupil thinks it play. He believes that to be sincere we must be serious. In these latter-day objections there is nothing new. Socrates met them all; Rousseau heard the cry of "fad"; Heyne, Pestalozzi, Campe, Knuth and Froebel met the carpist and answered him reason for reason, just as Copernicus, Bruno and Galileo told the reason the earth revolved. The professional teacher who can do nothing but teach--the college professor who is a college professor and nothing else--hates the Natural Method man about as ardently as the person who wears a paste diamond hates the lapidary. * * * * * Heinrich Campe was the tutor of the Humboldts for two years, when he entered the employ of the King as Commissioner of Education. After this, however, he continued to spend one day a week at Tegel for some time. He loved the boys as his own, and his hope for their future never relaxed. Possibly his interest was not wholly disinterested--with the help of these lads he was working out and proving his pedagogic theories. When Campe resigned his immediate tutorship he was allowed to select his successor, and he chose a young man by the name of Christian Knuth. The mother was a member of this little university of four persons; Knuth, of course, was a member, for he always considered himself more of a student than a teacher. When Campe resigned in favor of Knuth his action was in degree prompted by his love and consideration for the boys. Knuth was only a little past twenty, and was able to enter into the out-of-door sports and work of the youngsters better than the older man. Knuth was their hero--together they rode horseback, climbed mountains, excavated tunnels, mined for ore, built miniature houses. "Knuth made every good thing in Berlin available to us," wrote William years afterward; "we visited stores, factories, barracks and schools, and became familiar with a thousand commonplace things never taught in schools and colleges."