To any one who has a fair knowledge of human nature, a glance at the line pictures of the gentlemen who participated in the events with which this book deals will tell that they are men of character and keen observation. In San Francisco and throughout the West many of them are as well known as the Governor of the State. Their names need no introduction, and since they have been representative men for many years it is not necessary to say much about them. For the benefit of persons who know nothing concerning them, however, the following information is submitted:-- PATRICK CROWLEY, Chief of Police, was born in Albany County, New York, on March 17, 1831. When quite young he went to New York and worked in different printing-offices. He came to San Francisco in 1850, and worked in the mining-camps for two or three years. He was engaged in the boating business here, when in 1854 he was elected to the office of Town Constable on the Democratic ticket. He was re-elected on the same ticket in 1855, and from 1856 he was re-elected every two years on the old People's Party ticket till 1866, when he was elected Chief of Police. He held that office by election for six years, when he quit the force and went into the brokerage business. In 1878, by an act of the Legislature, the Board of Police Commissioners received the power to appoint the Chief of Police. The office was tendered him, and after considerable pressure he reluctantly accepted it, as he was making an excellent living at his business. He held the office by election or appointment for twenty-four successive years. His wide experience with criminals, bunko-men, and all sorts of tricksters gave him excellent training and amply fitted him for a thorough inspection of all that was done during the seances. In fact, it was his boast at the beginning of his sitting with Dr. Schlesinger that he had helped to trap the Eddies and other disreputable mediums, and that he would soon expose the fraud in the case in hand.