Laxmi Bachanalaya
Legally available public-domain books and openly licensed reading materials.
Jacques Futrelle
H. G. Wells
Upton Sinclair
P. G. Wodehouse
George Hayter Chubb
Various
Arthur Quiller-Couch
Edward Stratemeyer
Frank V. Webster
H. C. Bailey
Mary Grant Bruce
Frank Richardson Pierce
T. F. Tout
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.