PZ Myers on the word "agnostic"

PZ Myers expresses his contempt for the word "agnostic":

I've decided that when I invent my time machine, my first stop is going to be 19th century England, where I shall slap Tom Huxley upside the head and tell him that he's being a waffling coward by inventing a word that's going to paralyze freethinkers for the next 150 years or more.

Speaking of time machines, I've got a bleg for the collective. At my elementary school, we used a series of reading comprehension workbooks in the 4th, 5th, and 6th grades. Here's what I remember about them: (1) they were, I believe, published by Economy; (2) the 6th grade reader was entitled "The Dopplegang"; (3) the 5th grade reader was about a group of kids who were friends with a scientist who had invented a time machine that was shaped like a pumpkin.

I loved that 5th grade workbook. Can anyone tell me what it was called? I'm hoping to find a copy of it.

UPDATE: Thomas Knapp of Kn@ppster provided the clue I needed in comments. I should have been searching for "The Dopple Gang," not "The Dopplegang." That led me to find the titles of the 4th and 5th grade volumes: The Kickingbird Kids' Book Factory and The Scratch Papers. The name of the scientist with the time machine was Professor Scratch.

Now if I can get my hands on a copy, I can do some childhood nostalgia bookblogging!