ers since Galileo, each informing his successor of what discoveries his own lifetime had seen achieved, might have passed the torch of Science into our hands as we sit here in this room. Indeed, for the matter of that, an audience much smaller than the present one, an audience of some five or six score people, if each person in it could speak for his own generation, would carry us away to the black unknown of the human species, to days without a document or monument to tell their tale. Is it credible that such a mushroom knowledge, such a growth overnight as this, can represent more than the minutest glimpse of what the Universe will really prove to be when adequately understood? No! our Science is a drop, our ignorance a sea. Whatever else be certain, this at least is certain: that the world of our present natural knowledge
