Irish poet William Butler Yeats is perhaps the most well-known member of the Hermetic Order of the Golden Dawn, the influential secret magical society which originated in the late 19th century (and still exists in a number of forms today). Yeats was initiated into the order in 1890, taking on the magical name Demon est Deus Inversus—"the Devil is God Inverted." As the order fell into chaos in the early 20th century, Yeats struggled to keep it intact, but he eventually left the offshoot Stella Matutina temple in 1921.
In 2009, noted Tarot author and scholar Mary K. Greer blogged about an exhibit at the National Library of Ireland showcasing a number of Yeats's Golden Dawn tools and writings, including pages from his private magical journal. The exhibition is still online and I encourage you to view it here (although it is built in Flash and employs a clunky navigation system). Navigate to "Interactive" then click on "The Celtic Mystic" to see the showcase.
I also recently acquired a copy of the out-of-print and rare book, Yeats, the Tarot, and the Golden Dawn by scholar Kathleen Raine (The Dolmen Press, 1972), and was astonished to find it contained several black-and-white photos of Yeats's hand-crafted elemental weapons (magical tools).
In the above image, clockwise from top left, are: the chalice (representing the element of Water); dagger (representing the element of Air) and lotus wand (a general "all-purpose" wand); magical sword and sheath; and the Fire Wand.
Another photo, this one from the National Library of Irelands exhibit, shows Yeats's hand-constructed and painted Pentacle, which represents the element of Earth. You can see his magical motto, Demon est Deus Inversus, painted on the pentacle. All of the magical tools are inscribed with Hebrew names of angels, and some (noticeably the cup) feature the sigils constructed from their names (the odd geometrical figures). This image comes from the collection at the National Library of Ireland:
It is still quite thrilling to see Yeats's drawings in the notebook illustrating his progression through the grades of the order. Here, he has sketched and painted the angel
Michael Auriel. [An earlier version of this article stated the angel was the Archangel Michael, but someone on a Golden Dawn forum caught the mistake.]
And a beautiful gallery of pages from a Golden Dawn notebook from Yeats's uncle, George Pollexfen, can be found on Flckr, too.
The full story of Yeats and his involvement with magic and the Golden Dawn is covered in a number of books and online, but seeing these magical tools and drawings—carefully constructed and painted by the great poet himself—really brings the tradition alive.