Time somehow got away from me last week, and there was no Timeslip Tuesday. But I am back again today, with the book that I am currently reading to my eight-year old--The Time Garden, by Edward Eager (1958, 188pp in the edition I have).
According to the wikipedia article on Eager that I just linked to, he made "a distinct contribution to children's literature by introducing a theme of magic into the lives of ordinary children." Ordinary American middle class, not at all well of financially, children, who almost universally love the books of E. Nesbit. His best known book is probably Half Magic (1954), but two of my favorites are Knight's Castle, and The Time Garden, that tell of the adventures that happened to the children of the children in Half Magic.
In The Time Garden, Roger, Ann, Eliza and Jack have been dumped by their parents at an old seaside house in Massachusetts. There they discover a very old, magical toad, who dwells in a garden of flowering thyme at the edge of the ocean. All his magic has gone into the ground, so the thyme itself has become magical--a magic of time travelling. Transported back in time, the children raise the alarm when the British are coming in the Revolutionary War, help slaves escape on the Underground Railroad, visit Jo March and sisters, and the court of Queen Elizabeth. They also, most magically of all, travel back in time to one of the magical adventures of their own parents (I get a kick out of self-referentiality in books).
Eager, as a writer, allows himself to stray right to the edge of farce. The language and the situations are almost tongue in check. I think, though, that the delight he himself is getting from his writing, a delight that is shared by the reader (ie me, and presumably other Eager fans). I think his books are funny. He also creates great kids--girls that are daring, girls that are afraid, but brave enough to go through with things anyway, and boys that have thoughtful sides. (Except Jack, who is the oldest, and who has begun to notice Girls). And although there are, of course, no cell phones, and such like, the people, places, and situations do not feel especially dated.
Timeslip-wise, the magic is unworrying to the reader (that is, it is not explained so much as to become strained), although the children do their share of worrying about their effect on the past. This is, as far as I know, the only timeslip book whose catalyst is a magical toad.
My only faint criticism of Edward Eager is that his chapters are too long. I suggest the audio versions.