Crossword-Solution: VACUA 5 letters, 2 clues 🏆 scrabble score: 10

The study of apparatus for obtaining more perfect vacua was unceasingly carried on, for Edison realized that in this there lay a potent factor of ultimate success.

Now, however, that he had found means for obtaining and maintaining high vacua, Edison immediately went back to carbon, which from the first he had conceived of as the ideal substance for a burner.

Once in a while he felt it his duty to go over the ground with scientific visitors, many of whom were from abroad, and discuss questions which were not simply those of technique, but related to newer phenomena, such as the action of carbon, the nature and effects of high vacua; the principles of electrical subdivision; the value of insulation, and many others which, unfortunate to say, remain as esoteric now as they were then, ever fruitful themes of controversy.

Hence his conclusion, which, as we have seen, he makes general in its application to all matter, that there are spaces, or, as he calls them, vacua, between the particles that go to make up all substances, whether liquid, solid, or gaseous.

Still another kind of radiation has been discovered more recently by Thomson, who has found that in high vacua, rays become apparent which are absorbed at once by air at any ordinary pressure.