How We Learnt to Wake Up on Time

For most of human history, people did not need an alarm clock. They woke with the sunrise, the crowing of a cockerel or the noise of a household getting up, and in farming communities the working day was shaped by the seasons rather than by the clock. It was only when large numbers of people began to work in factories, where shifts started at a fixed time regardless of the light, that waking up at a precise moment became a serious problem. Even in towns, church bells and the calls of street traders marked the passing of the morning.

Mechanical devices to wake people did exist before then. Some monasteries used water clocks connected to bells to call monks to prayer during the night, and there are records of candles marked with lines into which a nail was pushed; when the wax melted down to that point, the nail dropped onto a metal plate with a clatter. Such inventions were rare and often unreliable, however, and they were far beyond the means of ordinary families.

In the industrial towns of nineteenth-century Britain, the solution was a human one. Men and women known as knocker-uppers walked the streets before dawn, tapping on bedroom windows with long poles or, in some cases, shooting dried peas at the glass through a tube. Workers paid them a few pennies a week, and the knocker-upper would not move on until they saw a light or a face at the window. The job was often done by elderly people or by police officers on night patrol, who earned a little extra money in this way.

Affordable mechanical alarm clocks began to appear in the late nineteenth century, and by the early twentieth century they were common in working households. Their loud bells were designed to be impossible to sleep through, and many models were advertised with claims about the dependability of their mechanism. Yet knocker-uppers did not disappear overnight. In some northern towns they continued working until the 1950s, partly because many workers did not trust the new clocks and partly because a person at the window could not be switched off and ignored.

Over the following decades, the alarm clock became steadily more sophisticated. Electric clocks removed the need to wind the mechanism each night, and radio alarms allowed people to wake to music or the news rather than a bell. The snooze button, which lets the sleeper silence the alarm for a few extra minutes, was introduced in the mid-twentieth century and quickly became one of the most popular features. Today, the majority of people use their mobile phones as alarm clocks, and the traditional bedside clock is becoming less common.

The design of the bedside clock also reflected changing tastes. Early models were plain metal boxes with two bells on top, but by the 1930s manufacturers were offering clocks in coloured cases, with luminous hands that could be read in the dark. Travel alarm clocks, which folded into small leather cases, became popular with business travellers, and digital clocks with glowing red numbers appeared in the 1970s. For many households, the alarm clock had become not only a practical tool but also a piece of bedroom furniture.

Not everyone thinks this is a good thing. Dr Simon Achterberg, who studies sleep and daily routines, points out that keeping a phone beside the bed can encourage people to check messages late at night, which delays sleep. He is also critical of the snooze button. Repeatedly falling back to sleep for a few minutes, he says, does nothing to make people more rested and may leave them feeling more tired than if they had simply got up when the alarm first sounded.

Some designers have responded with new kinds of alarm. Light alarms gradually brighten the room over half an hour, imitating sunrise, and are said to make waking gentler, especially in the dark winter months. Others use sensors to detect when the sleeper is in a light phase of sleep and wake them at the most suitable moment. Achterberg is cautious about the claims made for such devices, but he welcomes the idea behind them. In a sense, he says, the newest alarms are trying to recreate the natural waking that people enjoyed before alarm clocks were needed at all.