A: It’s merely a history writer’s gold.
If you click on the illustration to the left, you’ll see a larger version. Wikipedia says this is the “Musei Wormiani Historia,” the frontispiece from the Museum Wormianum depicting Ole Worm‘s cabinet of curiosities. In other words, it’s an entire collection of historical tidbits, or at least the physical kind.
If you’re writing a story set in a specific historic period, tossing in a reference or two about something common back then but obscure now does at least two things: it provides an interesting glimpse into the day-to-day business of living in that period, and it suggests to the reader that the writer knows whereof he or she speaks.
Consider a story set in the early 20th century, just over a hundred years ago. Even though motor cars had been around for a good 20 years, paved roads were still largely a novelty. In 1909, 22-year-old Alice Ramsey, an adventurish gal from New Jersey, climbed into her brand new, 30 horsepower Maxwell and headed due West. She became the first woman to drive completely across the country. She covered over 3,600 miles, and yet barely 150 of them were paved.
As late as the 1930s, streets in Manhattan were being paved with bricks. Imagine how such travel conditions might impact your story. Imagine traveling without a map or directions, let alone a GPS!
Here’s another thought, especially if you’ve got something of a political thriller in mind, and you’d like to use that same period. Imagine you’re standing outside the White House, smack in the middle of Washington, DC, when all of a sudden the lawn mowers appear. They’re pictured below.
The point here, of course, is to use these details to your advantage. If your character must walk across the White House lawn, there’s a better than even chance that he’ll arrive at the portico with something unpleasant on his shoes. Wouldn’t that make for an interesting scene?
Step back less than a generation, and sideways a bit to reach New York City, and you no longer have to worry about sheep droppings. Instead, you’ll have to navigate streets populated with about 170,000 horses pulling wagons, trolleys, and a wide range of other wheeled vehicles. Assuming these animals were reasonably well cared for, each one would produce several pounds of manure and a quart of urine each day. Where do you suppose it all went? According to published reports, the city had no sanitation department in the 1800s.
And when one of those poor creatures died, the carcass was left where it fell until it rotted down enough to make its removal more manageable.
Knowing such details is one thing, using them is another. It’s not a writer’s job to hammer historical facts into the reader’s head. Just because you dug up these tidbits doesn’t mean your readers must review them, too. Tidbits work best when they become part of the setting. What might be natural to someone living in New York at the turn of the 19th/20th century may have been shocking to someone from the future. But you don’t have to write science fiction to take advantage of such gems. Someone living a few hours away from New York might have a similar reaction.
Knowing your historical setting, and immersing yourself in it, gives you the opportunity to bring it to life. It’s normal, everyday stuff to your characters, but to your readers, it may well be the most interesting thing they encounter all day.