On a recent trip to the Dominican Republic my wife and I spent the day in the capital city of Santo Domingo. It is the largest city in the Dominican Republic and the oldest city in the Americas.

Square in historic centre of Santo Domingo
Square in historic centre of Santo Domingo
Central cathedral, Santo Domingo
Central cathedral, Santo Domingo

Although the city considers itself a European in style and architecture, in appearance it is not unlike any other city in the Caribbean. Most of the historic buildings are located in the Colonial Zone or Zona Colonial, a walled 16-square-block historic district with many firsts of the New World such as the first cathedral, university, and hospital. Most of our time was spent in this historic district where we saw museums, castles, churches, had a light lunch and this sundial.

Sundial in historic district Santo Domingo
Sundial in historic district Santo Domingo, showing 11:30am
Jesuit church, Santo Domingo
Jesuit church, Santo Domingo

A sundial is a device that tells the time when there is sunlight. It does so by casting a shadow according to the position of the sun in the sky. The part of it that casts the shadow is called the gnomon, a sort of shark-fin like object. As the earth turns on its polar axis, the sun appears to cross the sky from east to west, rising at sun-rise from beneath the horizon to a zenith at mid-day and falling again behind the horizon at sunset. Sundials indicate the local solar time only. Before the introduction of the mechanical clock, the sundial was the only source of time. Ironically, when the clcok was invented the sundial became more important as a way of regulating the clock as its accuracy was poor.

The Alcázar de Colón, or Columbus Alcazar is the oldest Viceregal residence in America
The Alcázar de Colón, or Columbus Alcazar is the oldest Viceregal residence in America
Torre del Reloj, clokc tower, Santo Domingo
Torre del Reloj, clock tower, Santo Domingo

Sundials have been invented independently in all major cultures and become more accurate and sophisticated as the culture developed. The earliest sundials go back to 1500BC from ancient Egyptian astronomy, however, humans were telling time from shadow-lengths at an even earlier date, but this is difficult to verify.

Indeed, we have come a long way from the sundial.

Unlike mechanical clock movements, they are easy to maintain. As they say, there are two clocks that should never be oiled, the Atmos and the sundial.