Chocolate cosmos (Cosmos atrosanguinea) is both nose and eye candy for your garden. When it’s in full bloom, mature blossoms on long, slender stems look like candy kisses on a stick and fill late afternoon with sweet scent of vanilla tinged chocolate. New blossoms hug foliage of plant, nearly concealing it with their numbers! Add to that sweet chocolate fragrance and you end up with something very special.

Although chocolate cosmos is endangered in wild, transplants are easily found at most nurseries and garden centers in spring. However, gardeners who are inexperienced in how to grow chocolate cosmos may overlook what seem to be small, messy tangles of miniature dahlia leaves, unaware that once established, prolific blossoms nearly conceal foliage. Once in bloom, chocolate cosmos blossoms continuously throughout summer into first frosts of autumn.

That's unfortunate, because it is not at all difficult to ensure that your garden sundial will be an accurate timepiece, provided, of course that sun is shining.

But that will be covered in another article. For now, let's see what a sundial is, and what it is capable of.

Sundial History

We forget in this modern age that accurate, affordable watches and clocks have been around for much less than 200 years.

Before then, sundials were one of few ways to tell time with reasonable accuracy.

Shadow clocks dated at 1500BC are known from Egypt, but first dials appear to have been Babylonian. The Greeks adapted idea, Romans developed it further, and by about 100BC had perfected horizontal sundial (and placed it in their gardens).

Even in ancient days some people had schedules to keep, and both agriculture and religion required knowledge of seasons and movement of sun to determine planting and timing of ceremonies.

The sundial was an important means of providing that information, and considerable advances in mathematics, geometry and astronomy were made while it was perfected. The knowledge gained forms part of foundations of modern science.

Types of Sundial

There are four reasonably common types of sundial.

They all have two things in common. Each consists of a raised structure, called gnomon (silent "g") which casts a shadow onto a plate called dial. The dial is divided into hourly or shorter time divisions and may also show other information.The part of gnomon whose shadow indicates time on dial is called style.

The most abundant form is horizontal sundial, happily sitting on its pedestal or column and adding beauty and interest to home garden.

Related is equatorial sundial, with its dial oriented at same angle as latitude. It works slightly differently, and is easier to use when properly calibrated.

Thirdly, there is vertical sundial, ideally located on a wall facing due south in northern hemisphere, and north in southern hemisphere. The principle is much same, but sundial only occupies a semicircular area. Vertical sundials displayed time to public, and were used to correct unreliable public clocks.