In a Word: Burning Your Backlog

Senior managing editor and logophile Andy Hollandbeck reveals the sometimes surprising roots of common English words and phrases. Remember: Etymology tells us where a word comes from, but not what it means today.

Most of us have experienced, in one way or another, the effects of a backlog, whether it was a tall pile of work in your own in-box or a long wait for the government to eventually get around to processing your paperwork. This “accumulation of tasks that need dealing with” sense of backlog, though, is a relatively recent addition to the English language, tracing back only to the 1930s.

The original sense of backlog (or back-log), going back to the 1600s, was a literal wooden log, a fairly large one that was placed against the back wall of a fireplace. Its size and placement meant that it burned slowly and concentrated the heat, useful features in times when a constant hearth fire was the only way to keep a family warm through cold winters.

By the late 1800s, this backlog had also taken on the sense of “something saved up to be used later.”

So backlog had a long history before the modern, usually annoying sense of the word came along — and it might not have happened if log hadn’t also evolved centuries ago into a nautical term for a daily record of a ship’s progress.

Here’s how it happened: In the days of all-analogue boating, sailors measured a ship’s speed using a tool called a log line. It consisted of a spool of rope with a flat, wedge-shaped piece of wood (called the log or chip log because, well, it’s a chunk of a tree) tied to the loose end. While the ship was moving, the log would be dropped in the water. It was weighted so that it would float perpendicular, creating drag and pulling rope from the spool as the boat moved away. Measuring how much of the rope played out in 30 seconds revealed the speed of the ship.

In earlier times, the entire rope was reeled back in and measured, but eventually sailors innovated and tied knots in the rope at regular intervals. That way, they could simply count knots as the rope played out. Each knot represented 120th of a nautical mile, and because 30 seconds is 120th of an hour, the number of knots that were pulled out equaled the number of nautical miles the ship could travel at that speed.

And this is why ship speeds even today are measured in knots.

But back to the log: The reading taken from the log line was recorded in the log book, which over time included other information as well — like weather, food stores, and crew health — creating a record of the ship’s daily progress. This type of log book, or simply log (as in captain’s log for you Star Trek fans), found a more common and generic sense outside of sailing as “a record of daily events or activities.”

In the 20th century, non-nautical logs were recording not only things that had happened but also things that needed to be done. People likely would still have understood backlog in the fireplace sense in the early 1900s, but it was also the perfect word for all those items on to-do lists that piled up faster than they could be crossed off.

So the next time you fantasize about setting fire to the tall stack of papers looming in your inbox, imagine doing it at the back of a fireplace — that is, imagine making a backlog of your backlog.

And then record it in your daily log.