I was led to a study of the subject when writing four new chapters on Astronomy for a new edition of The Wonderful Century. I then found that almost all writers on general astronomy, from Sir John Herschel to Professor Simon Newcomb and Sir Norman Lockyer, stated, as an indisputable fact, that our sun is situated in the plane of the great ring of the Milky Way, and also very nearly in the centre of that ring. The most recent researches also showed that there was little or no proof of there being any stars or nebulae very far beyond the Milky Way, which thus seemed to be the limit, in that direction, of the stellar universe.