View this post on Instagram A post shared by Mercer County Library System (@mclsnj) Subscribe | UPI Odd Newsletter Subscribe April 24 (UPI) -- A New Jersey library announced a book was recently returned anonymously after being checked out in July 1979. The Mercer County Library System said the book, Back to Basics by the editors of Flying magazine, was due back at the library's Hopewell branch July 25, 1979, but it didn't return to the library system until it was anonymously left in a box of donations earlier this month. Advertisement "We were kind of surprised because it was so old," Andrea Merrick, the Hopewell branch's manager, told NJ.com. "We all just kind of thought it was really neat, like seeing what the hours used to be and the 10-cent fine for if you lost the little card that was in there." Merrick said the library's records don't go back far enough to identify the patron who originally checked out the overdue book. Advertisement Librarians said the book would have accrued more than $1,600 in fines at the current rate of 10 cents per day, but the library caps fees at $6. Merrick said the library would not attempt to collect any fines if the person who checked out the book decides to come forward. Read More Family of bears bounce on trampoline in Connecticut yard Alligator lassoed after crossing South Carolina road Idaho man passes 40-pound weight from hand to hand for world record