Laxmi Bachanalaya
Legally available public-domain books and openly licensed reading materials.
Benedictus de Spinoza
Joshua Rose
Petrus Ramus
David Hilbert
John Dee
Stephen Leacock
Albert Einstein
W. W. Rouse Ball
David Eugene Smith
J. Malcolm Bird
Jean-Henri Fabre and Louise Hasbrouck Zimm
Derrick Norman Lehmer
Henri Poincaré
René Descartes
Bertrand Russell
Simon Newcomb
N. J. Lennes and H. E. Slaught
John Phin
Julian Lowell Coolidge
Various
Emil Weyr
Bernhard Marks
Claude Fayette Bragdon
Lewis Carroll
G. A. Wentworth
These books are free to read. Each is in the public domain in the United States; check your own country's rules before you copy or share one.