When Danny Dunn tips over the mysterious jar of glistening liquid, he has no way of knowing that he will involve himself, his friend Joe, and Professor Bullfinch in a wild flight between planets. But anything can happen when Danny is around - and practica
Are there enemy spies following Professor Bullfinch? Is he working on a secret government invention?Danny and his friends, Joe and Irene, decide they must warn the Professor of possible danger. They track him down to an old barn, where he's hidden his wor
By accidentally short-circuiting Professor Bullfinch's new crystalline material, Danny Dunn enables the professor to create a new machine that makes Danny invisible.
No more homework!Professor Bullfinch goes off to attend a scientific conference and leaves Danny in charge of his new miniature automatic computer called Minia. Danny calls it a midget giant brain and suddenly comes up with an idea. Could he program Minny