Seeking a children's story about a magic umbrella

Question

My younger brother, when was about eight, in the late 1980s, bought a book from a school book order. It was probably 50 to 100 pages long, divided into chapters, with a few black and white sketch illustrations per chapter.

The plot entailed some children (a boy and a girl, I think), who meet a silly sort of wizard, whose wand is in the form of an umbrella. The umbrella is quite temperamental. It doesn't work unless the wielder is polite to it, and it doesn't work at all unless it's raining (or maybe not raining).

The kids have some adventures, including making friends with the Loch Ness monster and accidentally getting him caught and put in a zoo, from which he needs to be rescued.

I would like to find this again. What was it?

Answer 1

The Trouble with Magic by Ruth Chew

When Barbara and Rick Benton find a wizard named Harrison Peabody in an old bottle, they quickly discover that magic isn't as simple as it looks. But even tricky magic is better than no magic, and soon the Bentons are flying around Prospect Park with a large black umbrella and befriending a sea serpent in the lake. How can they keep Harrison a secret, though, when he's living in their attic?

Delightful stories that deal with matter-of-fact magic, Ruth Chew's books have been engaging young readers for over 40 years. Now a new generation can discover the timelessness of these marvelous tales.

The reviews on Goodreads mention the sea serpent being taken to the zoo and them rescuing him, and the umbrella only working when it rains. Just to add additional details, they find the bottle when looking for perfume to cover up the smell of cabbage from their caretaker's cooking, and one of the bits of magic done early on is that their bedrooms smell of roses and pine respectively due to Harrison conjuring up plants of that variety that grow in their room. The reviews also mention the black-and-white illustrations.

Found by searching for book wizard "magical umbrella" (weirdly enough, adding "Loch Ness" to the search rules it out)