viii FROM PREFACE TO FIRST EDITION. subject of the Plurality of Worlds. The fourth paper relates to the application of the Rosse Telescope to determine the heat of the lunar surface. Then follow papers on Venus, Mars, and Jupiter ; two essays on Meteors, one relating to the past history and the other to the present condition of meteoric researches ; a paper on Tyndall's Theory of Comets (a subject deserving close examination), and another on the general phenomena of comets and comets' tails. The three papers on the Solar Corona might have been added, almost as they stand, to my chapter on. What we learn from the Sun,' in Other Worlds, but for the requirements of space. Lastly there is a paper on the Colours of the Double Stars, a subject which the same cause compelled me to leave almost untouched in that work. I have to return my thanks to the editors and publishers of the magazines from which these essays have been taken, for permission to reproduce them. R. A. P. |