I read this book when I was a kid and recently revisited it. As it turns out, while I do not have a photographic/eidetic memory or anything like that, I DO have a very good memory for the names of books I read when I was a kid (well, most of them) and so occasionally I like to go back and take a look at them ("M Is For Mischief" and "The Enormous Egg" will no doubt eventually get into my reading pile).
This is a charming book, easy to read and follow but with a surprisingly subtle hand at making its overall points. Harry (Houdini) Marco - son of a now-deceased stage magician, helps his single mom run a boarding house in San Francisco. Harry is clumsy and awkward but a good kid in general and so when he helps a strange, gnomish man who lost his suitcase on the bus, he is rewarded - but the man (Mr. Tarzack Mazzeeck) is an employee of the A.A. Comus Company (and a former member of A.O.A.T.S - "The Ancient Order of Authentic and Traditional Sorcerers") and so the reward takes the shape of bottle of magical unguent that allows Harry to grow wings and fly, a spell that can be activated and deactivated. And so Harry spends what he had previously expected to be a boring summer instead flying all around, learning lessons, recusing people and generally being an inspiring force for good, when he isn't crash-landing.
I had remembered the broad strokes of the book but not the details. Specifically, I remembered how I reacted when the end of the book approaches and Harry realizes that the ointment is almost gone - and I remember taking something from the philosophical attitude that Harry adopts, as crushed as I was. And the final revelation that all the physical exercising of his wings had bulked up Harry's physique and made him more fit and dexterous also stayed with me. Also, I remember thinking of this book when I eventually read about the X-MEN superhero mutant Angel, who had similar wings. Read as an adult, there is some cute bits of kid's writing ("for Pete squeaks" substituted for "For Pete's sake"), some solid invention (Harry's improvised flying costume made from draperies essentially makes him look like a classical angel decked out in robes) and I like how the book acknowledges that kids can get depressed (Harry "worked himself up into a case of the blues") over not feeling good enough, while still playing that detail lightly.
But there's a lot of heart here, as well as a nice sense for young readers of a world larger than themselves, of thoughts they might have that are deeper and more grand, of the less obvious and the awesome hiding in plain sight. A specific detail that the wings evoke in Harry a kind of pride and fascination is subtly twinned with the intended and inadvertent positive affects he has on the world around him (inspiring a man to quit drinking, inspiring a neighborhood shrew to be a better person, rescuing little kids). And Harry is written as benign enough that even though he scares away a woman who poses a rival remarriage threat to his mom, he feels bad about it afterwards.
A really solid kid's book - glad I stumbled across it as a kid, glad I reread it as an adult.