By Charles Layton

This week I read a news story about the jobless recovery. It said that even though companies still aren’t doing much hiring, their investment in new equipment has gone “into overdrive.”

That little metaphor struck me as a tad old-fashioned. It feels like the early 1960s. I expect the day will come when people no longer even get the reference. “On steroids” means much the same thing but is more contemporary.

Trends in metaphors follow changes in technology, science and life style. Take the way we visualize our brains. Nobody knows how thought really happens, so we use metaphors. The age of mechanization gave us expressions like “The wheels were turning in his head” or “He’s got a screw loose” — clock metaphors, I suppose those are.

Thomas Edison not only invented new electrical gadgets, he also gave cartoonists a handy way to characterize brain activity – an idea came to be represented by a light bulb! (Before we had light bulbs we had weather metaphors. A new idea would “dawn” on us, like the sun coming up. Or we’d have a “brain storm.”) More recently, we’ve started saying that our minds are “hard-wired,” which is a bit more modern. Thanks to the advent of data processing, we also say, when we don’t understand something, that it “doesn’t compute.”

Jesus told his followers, “Take my yoke upon you,” which held its currency for nearly two millennia. But if Jesus had been preaching in the 20^th century you know he’d have used something more contemporary – like maybe a car metaphor. Or even, in our own time, a reference to the Internet.

The more abstract a thing is, the more metaphorical our descriptions of it need to be. Just about everything we say or think about the Internet is a metaphor. We speak of it in terms of roads (the information superhighway, fast and slow lanes, traffic, crashing) and water (surfing, navigating, streaming, piracy) and physical space (“the cloud”).

As old practices and technologies die out, the metaphors about them grow obsolete and their origins are forgotten. Still, they hang around for a while. We all understand what “cash on the barrel head” means, outdated as that is. To “drop the dime” on someone still means to tattle on them, even though we no longer have pay phones.

You probably know that our expression “bite the bullet” refers to a wounded soldier biting a musket ball to keep from screaming during field surgery. You may also know why we call an unreliable person “a loose cannon.” It’s a naval metaphor, referring to an unsecured cannon sliding across the ship’s deck – a wonderfully vivid image.

But I bet you didn’t know that the word “aboveboard” is a metaphor referring to a card player at a table (which once was called a “board”).

You did know that? OK, how about the word “aftermath.” It’s a completely dead metaphor, and it comes from farming. A “math” used to mean a patch of mown hay or grain. And an “aftermath” was the grass that sprang up after a farmer had mowed a field. Now that I’ve told you that, you’ll think of it every time you see the word aftermath.

Here’s a Cole Porter song that’s one long string of metaphors, some of them quite dated, others less so. The singer is Louis Armstrong, who is of course timeless.