Campbell's conscientious biographer appears to have felt that the value of this charming account of his interview with Herschel was in its report of astronomical facts and opinions, and he adds a foot-note to explain that "Herschel's opinion never amounted to more than hypothesis having some degree of probability. Sir John Herschel remembers his father saying, 'If that hypothesis were true, and if the planet destroyed were as large as the earth, there must have been at least thirty-thousand such fragments,' but always as an hypothesis—he was never heard to declare any degree of conviction that it was so."
For us, the value of this sympathetic account of a day in Herschel's life is in its conception of the simplicity, the modesty, the "boyish earnestness," the elevation of thought and speech of the old philosopher; and in the impression made on the feelings, not the mind, of the poet, then thirty-five years old.
