Hardy Boys Mystery #173 Speed Times Five

[Hardy Sleuth]

Yep- A Secret in Time features another Nancy Drew mystery and adventure involving the Crowley clock...
You can get a copy here, but I don't know if you want to pay that much for it...you can probably find it cheaper somewhere else online- maybe Ebay or another bookseller (www.abebooks.com is a good one.)
I've got a copy of this book that I ran across a while back- I thought it was nice to have for my very limited Nancy Drew collection. One of these days I want to read The Secret of the Old Clock and A Secret in Time back to back.

Cool, thanks for the links! Yeah, I'll try to find it for less. That would be fun to read one right after the other!

Not quite, since the old copyright dates weren't added to the copyright page till 1987, and then before that Grosset & Dunlap had added a line of text to all the books, starting around 1980-81, just after the court decision saying "Copyright assigned to Stratemeyer Syndicate 1980", with the original revised copyright date still on the copyright page reading "Copyright 19xx by Grosset & Dunlap, Inc.", although on some of the books in the late #20's and #30's they did have both the original and revised copyright dates. 

But for "The Tower Treasure", any copy from before 1987 would've had the  1959 date, with the odd few having the 1980 date.

Like I was saying, the author could have read/seen any edition of #1 The Tower Treasure, original and/or revised, new or used out-of-print that was published prior to writing #100 The Secret of the Island Treasure (published in 1990).