Semaphore.

Buried in a NY Times article about the backlash from a Colorado homeowner's association banning a Christmas wreath in the form of a peace symbol is an explanation for its origin:

The peace symbol came to prominence in the late 1950s as the logo for the Campaign for Nuclear Disarmament, a British antiwar group, according to the group’s Web site. It incorporates the semaphore flag images for the letters in the group’s name, a “D” atop an “N.”

Thanks for the memories, Ernestine.

Written by two of pioneering motion-study expert Frank Gilbreth's 12 children, the 1948 memoir "Cheaper by the Dozen" was a highly entertaining account of a very unconventional childhood. It was one of those books around our house that I read over and over as a child. I was not alone, as Jonathan Yardley wrote in 2003:

"Cheaper by the Dozen" was one of the cherished books of my boyhood ...

My memories of "Cheaper by the Dozen" remained happy over the years, but it was with a measure of apprehension that I opened the book recently. The books of one's childhood rarely age well into one's late adulthood, no matter how affectionate (and dim) one's memories may be. Yes, I love C.S. Forester's Horatio Hornblower novels as much now as I did when I was a boy, but those are the rare exceptions; mostly the literary pleasures of childhood and adolescence are best left undisturbed in later years.

So it is a joy to report that "Cheaper by the Dozen" still reads remarkably well. It is not a work of literature and no claims will be made for it as such. It is about American family life at a time (the 1910s and 1920s) now so impossibly distant that today's teenage reader may be unable to connect with it. Yet families are families, then as now, and I like to think that young readers would respond to the Gilbreth family's joys and sorrows just as I and millions of other, older readers have.

(In case you're wondering, the 1950 film does a decent job of depicting it, but the 2003 version just used the idea of a family with 12 children as a premise.)

Today the New York Times reports that the surviving author, Ernestine Gilbreth Carey, has died at age 98.