Dr. Drabble, Genius Inventor Books

PJ and Chelsea are going around the world in Dr. Drabble's Brilliant All-in-One Traveling Apparatus. When the doctor invents a duplicating machine, they decide it's a great way to "make" new friends in the Philippines. In the end, however, they see that the trouble they cause is hardly worth the effort they save.

A story of forgiveness 1991 Victor books

PJ and Chelsea are going around the world with their missionary parents in Dr. Drabble's Brilliant All-in-One Traveling Apparatus. On their way to England, Dr. Drabble invents a special dust that makes objects float in the air. Chelsea and PJ use their new flying power to search for God, but a near-disaster teaches them something wonderful about His presence.

While traveling around the world with their missionary parents in Dr. Drabble's Brilliant All-in-One Traveling Apparatus, PJ and Chelsea use Dr. Drabble's mirror to make themselves invisible, trot off to explore Japan, and discover that being invisible has its drawbacks.

"A story about prejudice" for children from Scripture Press.

Dr. Drabble's latest invention allows P.J. and Chelsea to breathe underwater and talk to fish. It is great fun until they bump into a tricky fish named Murgatroyd. The kids find out that it's better to be truthful than lie.

Dr. Drabble's funny machine can duplicate anything--even doubles to clean your room and do your chores. What a great idea! That is, untli P.J. and Chelsea break a promise and use the machine on their own. This very funny book has a wonderful message about keeping your promises.