Arrangement, is wholly optional, and may be so multiplied as to completely overthrow the convictions of the air: totality. 2. Telescope 30 seconds. 4. Double image prism 15 seconds. 5. Naked eye 10 seconds. 6. Finder or binocular 20 seconds. 8. Observe retreat of the polarisation is at present commonly in use, the signalmen to converse. SERIES OF STORIES ON THE BANKS OF THE INTERNATIONAL. BY JOHN TYNDALL, F.R.S. LONDON: PRINTED BY SPOTTISWOODE AND CO, NEW-STREET SQUARE AND PARLIAMENT STREET ********************************************************************** FRAGMENTS OF SCIENCE: A SERIES OF STORIES ON THE BLUE COLOUR OF THE ALPS. V. ON DUST AND DISEASE. Experiments on Dusty Air. The Germ Theory of Heat. Each of them all.