Yes, upon hearing the title I also thought this free ebook was probably weird porn of some sort, but it’s not-- it's just plain weird:
Title: Odd Showers: or, An Explanation of the Rain of Insects, Fishes, and Lizards; Soot, Sand, and Ashes; Red Rain and Snow; Meteoric Stones; and other Bodies
Author: Gibb, G. Duncan (George Duncan), Sir, 1821-1876
Note: London: Kerby and Son, 1970
Note: Sounds like our English ancestors needed really sturdy umbrellas!