Ralph Milne Farley 
Earthmen on Venus, or, The Radio Man [EPUB ebook] 

The novel concerns electrical engineer Myles Cabot, who disappears from his home in Boston while performing an experiment. He finds himself transported to the planet Venus where he is captured by the Formians, a race of ant-like creatures. After learning of the Cupians, a human-like race that is subservient to the Formians, Cabot escapes and falls in love with the Cupian princess Lilla. He goes on to introduce the Cupians to gunpowder and leads them in a revolt against their Formian masters.