The late Victorian and Edwardian era was filled with confidence — indeed, bumptiousness — and the detective story was a part of that world. The progress of science and technology seemed inevitable, and the improvement of the human race appeared to march along in step. Even the mysteries of the human mind seemed susceptible to scientific explanation with the investigations of Sigmund Freud and Carl Gustav Jung. Fictional sleuths shared in this optimistic understanding of science. The first genuine scientific detective was Dr. John Evelyn Thorndyke created by R. Austin Freeman and first appeared in 1907. In 1909 William MacHarg and Edwin Balmer published the first story about Luther Trant, the first fictional sleuth to use psychoanalysis in his detection, and one of the first to feature a lie-detector test. What Trant (and the authors) mean by “psychology” is one’s physical reaction in telling the truth or a lie, and upon the instruments that can measure that response. Eventually, a great number of machines is either used or referred to in the stories: chronoscope, galvonometer, automatograph, electric psychometer (or “the soul machine”), sphygmograph, plethysmograph, kymograph, pneumograph. Nowadays, we would find psychological interpretation to be less absolute, and the lie-detectors and other machines to be less dependable, than MacHarg and Balmer believed. But the stories are more than just the application of gadgets. Trant often makes subtle deductions from physical evidence before he employs the machines. The backgrounds of the stories are varied and colorful – Aztec magic, exotic ports, shipwreck, Russian radicals, the deep woods, mixed marriage. *The Achievements of Luther Trant* was published as a book in 1910 after the first nine stories had appeared in *Hampton’s* magazine. It included a few of the original illustrations by William Oberhardt; his later fame as a portraitist was already evident in many of the finely wrought illustrations for the Trant stories.