It is claimed, for instance, that although these ponds are invariably found high up on the hills, far from the shade of trees or protecting copse, where no streams have ever flowed, they seldom if ever dry up even when the valleys are parched and the springs reduced to mere trickles.

Tradition, or long usage, has given to them the name of Dew Ponds, and romance has attributed certain of the older ones to the work of Stone Age men.

There is, of course, no record of the making of the first Dew Pond; but in Neolithic times, when most of the country was covered with forest in which lurked wolves and other fierce animals, the early men made their homes on the highest portion of the downs and it may be that these prehistoric folk learned the secret of securing the water they needed for themselves and their cattle on these exposed heights.

The secret of making these ponds is still known to a few and occasionally a new pond is constructed, or an existing one repaired, by some wondering rural expert.

The general method is to dig a saucer-shaped bed on some part of the downs where mist is apt to collect early on summer mornings. In this hollow, after the chalk and flints have been well rammed, is placed a good layer of straw or reeds on top of which is puddled a covering of clay and in some of the more modern dew ponds a final coating of concrete is used. All are wrought with experience and craft that is a heritage from the past, and then left to dry.

Then, when once the pond has filled (occasionally assisted by artificial means) there will always be water for the cattle to drink, even though no rains fall and the torrid sun pours down its relentless heat day after day.

It would be incorrect to say that there are no dry dew ponds, for they are often to be seen on the hills. But the reason is not far to seek. Once the bed of the pond is cracked or broken the water soon trickles through and the pond naturally fails. That is why a number of dew ponds are fenced, to prevent heavy cattle from wading into them and damaging the bottom.

Scientists have spent many years in trying to probe the mystery of how and whence the water comes that fills these lonely hollows of the hills but so far without success.

The generally accepted explanation is, however, that on a warm summer’s day the ground round the pond is warmed; but its heat cannot get to the clay bed of the pond because of the non-conducting nature of the layer of straw. Therefore when night falls, the cooler clay attracts more moisture from the atmosphere, and so counteracts the evaporation under the hottest of days.

But whatever their origin, or the mystery of the water supply, this much appears to be beyond dispute – that they have stood on the hills thousands of years before men sought to explain them.

From ‘The Wayfarer’s Book’ by E. Mansell