Thomas M. (Thomas Matthew) St. John

Thomas M. St. John, identified in public-domain editions as Thomas Matthew St. John (1865–1949), wrote popular instructional books that introduced readers to elementary electricity and magnetism through simple home experiments. His best-known titles include Things a Boy Should Know About Electricity, The Study of Elementary Electricity and Magnetism by Experiment, and How Two Boys Made Their Own Electrical Apparatus.

His books present science as something to be explored directly, with homemade devices, clear demonstrations, and a strong do-it-yourself spirit. In editions of his work, he is also credited as "Met. E.", and one title page places him at Cascade Ranch, East Windham, New York, while another lists a New York City address.

Although detailed biographical information is scarce in the sources I found, his work clearly belongs to the tradition of early 20th-century practical science writing for young readers. What stands out most is the inviting tone: instead of treating electricity as abstract theory, he showed beginners how to learn by making things with their own hands.