''However, with the Ragged Astronauts sequence, the author returned to his very best and most inventive form, describing with joyful exactness the sensation of emigrating, via hot-air balloon, up the hourglass funnel of atmosphere that connects two planets which orbit each other. Later volumes lost some of the freshness and elation of the first, but the series as a whole emphasizes his genuine stature in the genre as an entertainer who rarely fails to thrill the mind's eye with a new prospect. '' (Encyclopedia of SF: David Pringle & John Clute)