The dead of night evoked a fear in our ancestors that’s hard for us to imagine today. Most of us would be hard-pressed to recall when we were last engulfed by absolute darkness. Imagine a corner with shadows so dark that a stranger could lurk there without our knowing. With access to manmade illumination around the clock, we don’t worry ourselves. Our ancestors nightly locked doors and barred windows against wild creatures and things that howled at night—or against rough folk who waited in alleyways to do them harm.

Terrible things happened in the dark. Conversely, some monsters hide in dazzling light.

I started writing this piece to familiarize myself with a 19th-century illumination technology—gas lighting. I’d just read The Sister’s Tale, an exquisitely researched novel in which fellow Canadian historical author Beth Powning surprised me by mentioning interior gas-lit fixtures. Although on a fact-finding mission, my personal experience of a different kind of gaslighting began twining itself into the writing. So, I’m giving my pen free rein.

Although I’m now married to a loving and supportive partner of 26 years, my first venture into matrimony subjected me to gaslighting and other impactful behaviours. Twelve years in, I had become a husk of my former, already-shy self. It’s fair to say, I’m rebuilt from the ground up. The echo of my experience remains with me, although at a much lower decibel.

I’ll speak of it here in the gentlest terms.

I would never have guessed that gas lighting was used by North Americans as early as the War of 1812, in which America invaded Upper Canada (unsuccessfully!). What kind of gas was used? How was it piped to homes?

Chaldrons of coal were heated, and the resulting gas collected and stored at gasholder houses, then sent short distances through pipes to nearby homes. The earliest pipes were made of wood and later replaced by cast iron. According to Wikipedia, in 1817 London, England, two companies burned 28 chaldrons of coal between them each day and fueled 84,000 lights.

Gas lighting changed lives and benefited the Industrial Revolution. Where work had been limited to daytime hours, improved lighting meant businesses could extend the workday. People could safely go out at night and socialize instead of shutting themselves indoors when the sun went down. Demands for entertainment increased.

The term “gaslighting,” in reference to emotional and psychological abuse, arose from a 1938 play by Patrick Hamilton entitled Angel Street. The play was later performed under the name Gas Light. It was about a man eager to convince his wife that she was mentally unstable. He’d challenge her statements and correct her in a manner meant to humiliate her in front of other people. At every turn, he’d contrive situations that made her question her grasp on reality.

His primary strategy was to tamper with the intensity of the gaslighting in their home. He’d adjust the light, making it brighter for a while, then dimmer, and brighter again. When his wife would comment on the fluctuations, he would tell her it was all in her imagination—the lighting had been consistently appropriate. She began to doubt her sanity, and her anxious behaviours multiplied.

Gaslighting has since become synonymous with any behaviour that causes a victim to question their perception of reality. The aim is to make her question her ability to discern reality from fantasy. It’s a commonly used strategy by abusers.

This showed up in my life in so many ways. It was the culmination of small events that emotionally unbalanced me. The man would say upsetting things, then minutes later, when I challenged him, he’d adamantly deny having made those comments. On days when I dressed nicely, did my hair, and wore make-up, he’d tell me I looked horrible and ask if I was feeling alright. I thought I looked nice. Now I wasn’t sure.

Gas lighting illuminated entire rooms to a degree not possible with a candle or kerosene lamp. But it also posed new dangers. While gas lights were regarded as an improvement over candles, they still required manual lighting and extinguishing. This new convenience came with unpleasant and sometimes deadly side effects.

Unclean gas produced odours in the house. Victorian ladies are known for fainting due to tightly laced corsets, but they may also have been suffering from a lack of oxygen. During combustion of the coal gas, carbon monoxide was produced. The inhalation of carbon monoxide interferes with oxygen being carried through the bloodstream and results in suffocation. And then there was the risk of gas explosions! Gas fires fed on lavish Victorian draperies which were, of course, untreated by fire retardants.

I emerged from my gas lit years 27 years ago with a brain injury—the result of an assault. One of the lingering effects is extreme light sensitivity. Light that is not bright to most people is excruciating to me. Exposure to bright LED lighting sparks a sensation of bees buzzing inside my head and of a fist pushing against the base of my skull. If overexposed, I’m struck down by a seasick, room-spinning-in-circles kind of migraine. Even when I face away from the screens, my brain is affected.

A lot of 19th-century people found gas lighting—the equivalent brightness of six candles—to be uncomfortably bright. Users softened the brightness by sliding frosted globes over the fixtures’ glass chimneys. Also, on gas light fixtures, there was a key that could be turned to reduce gas flow and thereby dim the light.

This past winter, we experienced a six-day power outage following an ice storm. I read nightly by kerosene lamp and found the light surprisingly intense. The Glanmore National Historic Site posted a short video that addresses caring for oil lamps, wick trimming strategies, and gaslight operation.

I’ve developed my own strategies and shades to dim brightness, whether I encounter it through room lighting, Apple Watches, laptops, payment terminals, ATMs, cellphones, public signage etc. Even my writing process is designed around my brain injury and resultant light sensitivity.

My laptop screen is black with grey font, set at its lowest brightness and overlaid with two privacy screens. I also wear inexpensive amber-tinted glasses over my prescription glasses. My cellphone is set to its lowest brightness, and the blue-light blocker is turned on. In public settings with problematic lighting, I wear prescription glasses with the darkest available F-41 lenses. These glasses are great for my author events!

I confess that this exploration of gas lighting has introduced me to an unexpectedly interesting history of illumination. It has also left me wondering how much brightness is too much. Our great-great-grandparents’ candlelight produced 12.5 lumens. Today’s 10-watt LED bulb emits 800 lumens.

What would our ancestors say about that?