 "The Lonely Mountain Jar Inscription", the first published Tengwar sample, dates to 1937 ("The Hobbit", most editions with colour plates).The full explanation of the tengwar was published in Appendix E of "The Lord of the Rings" in 1955.The "Mellonath Daeron Index of Tengwar Specimina" (DTS) lists most of the known samples of tengwar by Tolkien.