What a very different picture many an outsider draws of the manner in which a seeker in the heavens works! He is imagined like Tycho Brahe to be surrounded by unusual pieces of apparatus, spying through the ocular of a long range refractor into the universe, seeking to unravel its ultimate secrets. The true picture does not correspond to this fancy in the slightest. Nothing in the make-up of the room reminds one of super-earthly sublimity, no abundance of instruments or books is to be seen, and one soon becomes aware that here a thinker reigns whose only requirement for his work, which encompasses the world, is his own mind, plus a sheet of paper and a pencil. All that acts on the observatories outside, that gives rise to great scientific expeditions, that, indeed, ultimately regulates the relationship of mankind to the constitution of the universe, the revolution in the knowledge of things connecting heaven and earth, all this is here concentrated in the simple figure of a still youthful scholar, who spins out endless threads from the fabric of his mind: the words of a poet are recalled to our memory, which, addressed to all of us, have been fulfilled to the last degree by one living among us:-- "Whereso thou roamest in space, thy Zenith and Nadir unite thee-- This to the heavenly height, that to the pole of the world,-- Whatsoever thou do, let thy will mount up into Heaven-- But let the pole of the world still o'er thine actions preside." (Schiller: _Translation by Merivale_.) And this one helped to fulfil this aim and I must break off his thread of thought to put the question: What is Discovery, and what does it signify? It is a purely abstract question that may appear to many to be devoid of content. Such will repeat to themselves, as best they can, the list of discoveries and think a man makes a discovery when he finds out something important, such as the Laws of Falling Bodies, the formation of Rainbows, or the Origin of Species: a general denomination may be found for it perhaps only by ascribing to Discovery something requiring a powerful mind, a creative genius. At first it staggered me to hear Einstein say: "The use of the word 'Discovery' in itself is to be deprecated. For discovery is equivalent to becoming aware of a thing which is already formed; this links up with proof, which no longer bears the character of 'discovery' but, in the last instance, of the means that leads to discovery." He then stated at first in blunt terms, which he afterwards elaborated by giving detailed illustrations: "Discovery is really not a creative act!"