Sometimes one hears that the census is like getting a snapshot of a family taken every ten years. The time between “exposures” does change from place to place but many countries have settled into the once per decade pattern. In the U.S. state censuses can sometimes be used to cut the time that the shutter is closed down to five years but it is still a pretty extreme form of time-lapse photography.
Often we might wish that the census was taken more often, that the enumerators clicked the census camera’s shutter a bit more often. In other cases ten years isn’t such a bad time between exposures. It is always possible that nothing much happened. The family stayed put. No one died. No one was born. The same people can be found in the same town with minor changes, decade after decade in some cases. That might be true but is it really what happened?
I’m working on a great example of when that isn’t at all what happened. In one census we can find father, mother, son and daughter. The two children are in high school. Ten years later in the same town, but a different house, we find the same four people making up a household. They are ten years older and the children are working but if this was all one had it would seem to clearly be one of those nothing-much-happened situations. Except that in the intervening ten years both children had moved hundreds of miles to attend elite universities; mother and daughter traveled to Europe where they lived several years as she furthered her education; the father, not needing a house for a whole family, sold it; the son worked his way to Europe on a steamer, returned, and graduated from law school; another house in the same town was purchased and the whole family reconvened just in time to be recorded as if they had only moved down the street.
A lot can happen between clicks of the shutter even if the pictures taken show little change at all. You only learn it by looking elsewhere while the census shutter is closed.