Freeman paid a great deal of attention to details, and carried out the experiments described in his books to ensure that they worked and would give the expected results. He also went to the trouble of visiting the places he wrote about so that the details in his descriptions were correct. De Balcam says that "Freeman displays a mastery of craftsmanship" in every story, and that he always used the language of the trade concerned. Freeman is "a man who writes of things that he has seen, handled and understood, and not of things that he has met only in print, or in a hazy, inattentive observation." This is a critical aspect of Freeman - he tested the methods he used. The top floor of his house was a workshop and laboratory, and his books sometimes included drawings or micrographs illustrating the evidence.