The broken iron ax

Detective novel with historical details 19th century. A detective, who worked first a a trapper with Indian tribes in the North of America and then as detective of the Pinkerton agency during the construction of railways to San Francisco, try to help again his friend, Miss Herenby, young archaeologist. John did not knew the Senecas tribe which indian name was Oas-in-in-ka. They used to practise the Three Sisters cultivation. and he did not understood why North American Indian did not use gold for their jewels. Several years after their travel in Egypt to found the father of the archaeologist and a Pharaho's bludgeon stolen in the United States, John, detective in the Central Pacific, and his friend Robby, owner of a dairy farm, try to help the young lady to found her fiancé, disappeared near San Francisco. The boyfriend was working in the building of the Suez channel when he meet Miss Herenby. What found the french fiancé of Miss Herenby before near San Francisco, a gold mine?