I remember reading two books by the same author one summer when I was about 10 to 12 (I was born in 68.) I think there was a brother and a sister who may have been staying at an old house with a grandfather or uncle and they find some sort of magic item. There may have been a magic genie involved. Not sure. I do distinctly remember one scene from one of the books and the brother, I believe, is caught in a large bubble and travels either to another place (the desert maybe) or travels to another time. The other book by same author was similar but not sure if it contained the same characters. Seems like covers were similar but with slight variations. May have had a house on the front.
Magic Treehouse?
Wonder if it was one of Edward Eager books?
Not magic treehouse. I read it in late 70’s. There was a scene where the boy was in this large floating bubble that carried him away somewhere.
Could they be books by Jane Langton? The plot you describe has some similarities to her book The Diamond in the Window.
I think that is it!!!! Thank you so much. This has bugged me for years!!!
Perhaps Hubble’s Bubble by Elaine Horseman? The kids involved are named Alaric and Sarah and they go to stay with their grandfather.