Many of the magicians in the Oz series mix technology with magic, and the Wizard of Oz is no exception. In fact, with his background in the Great Outside World and his resourcefulness, he’s one of the most prominent inventors in the books. Back in his humbug days, he created some quite intricate props to fool visitors, some of which we see when Dorothy and her companions ask him for favors in The Wonderful Wizard of Oz. Unlike in the movie, he doesn’t have complex machinery to work his illusions, instead relying largely on his own skill with ventriloquism. Still, he shows a clear interest in how things work, and it’s not too surprising that this continues when Glinda teaches him magic. I suppose you could say his first invention is a bubble-blowing machine that he uses to entertain the guests at Ozma’s birthday party in Road. The soap bubbles it makes are fortified with glue to make them last longer.
While it’s Santa Claus’s magic that enables some of the guests to ride home in the bubbles, this might be one of the Wizard’s first experiments with real magic, which he uses much more of in the following book. Emerald City actually credits him with inventing the Education Pills, although L. Frank Baum later names Professor Wogglebug as their inventor. Also, while not the original inventor of the Wishing Pills, he makes his own in the Ruth Plumly Thompson books.
It’s really Thompson who promotes the idea of the Wizard as inventor, starting in Royal Book with a mention of a magic radio that allows watchers of the Magic Picture to hear as well as see. He had done work with radio before as well, as evidenced with the radio telephones in Tik-Tok, which could probably be considered the world’s first cellular phones. In Yellow Knight, we first read about the Wizard’s Searchlight, which can find things and flash back their location. In Ojo, it can also lead its bearer directly to what they’re looking for. And Ozoplaning makes him not only the inventor of the Ozoplanes themselves, but also of Falling-Out Suits, which are sort of like inflatable pajamas that can be used in lieu of parachutes. And his Tell-all-escope is a spyglass that tells all it knows about whomever or whatever it’s pointed toward.
In the Neill books, one of his most prominent inventions is the Teletable, a mechanical device that can find lost people and objects. It is composed of the Compound Gazabo and Goggle-optics, and its Trumpet Eye works by putting your eye to it to listen and your ear to look.
Others are the laser-like Ozmic Ray, the teleporting Ambassa-Door, the Tattlescope, and of course the Scalawagons. Other authors have picked up on the idea of the Wizard as inventor, and given him other magical and mechanical devices as well.