Cheiro set out his method across several widely reprinted books, most notably Cheiro's Language of the Hand (1897), Palmistry for All (1916) and Cheiro's Book of Numbers (1926). His palmistry followed the standard Western tradition of reading the major lines and the mounts of the hand, the raised areas at the base of each finger and across the palm associated with planetary qualities, and paired that reading with a numerology system he presented as Chaldean in origin, deriving a person's governing number from the letters of their name.
However uncertain the details of his own biography, his books did more than any other single author's to fix the vocabulary of popular Western palmistry for the twentieth century, and the terminology he used for individual lines and mounts is still the terminology practitioners default to today. The system carries no scientific standing as an account of character or fate, and the atlas describes it as the popular tradition it is rather than as verified knowledge. His numerology diverged from the Pythagorean school that dominates English language numerology today, deriving instead from what he called Chaldean correspondences between letters and numbers, a distinct lineage that later popular numerologists have sometimes merged with the Pythagorean system despite the two resting on different letter to number tables entirely.