When the naturalist and curate Gilbert White was keeping his "Garden Kalendar" and "Naturalist's Journal", in which he also included such social occasions as the first hot-air balloon, the making of raisin wine, the use of his dog's white hair combings as an ingredient for ceiling plaster, he probably thought that his 40 years of journal writing would be little more than a meticulous inventory of local wildlife and nature for his own interest.
But 250 or so years on, these accounts are often curiously apposite. There are frequent mentions of unusual weather conditions - and even examples of air pollution. One June there's an epidemic of feverish colds throughout the country; during one February, there is a day of perfect summer sunshine; a strong smell of smoke coming from London shows that pollution is not just a modern phenomenon.
No wonder White's Natural History of Selborne is world famous. He is not only regarded as England's first ecologist, but also praised for his remarkable economy of style: "Bees rob each other fight" (February 17, 1779) and "The grasshopper-lark whispers at night" (May 26, 1777).
Such entries give us such a sense of presence that immediately we are transported to the 1700s, among the farm tracks, the "hollow lanes" and the hedgerows whose progeny he noted so precisely and charmingly.
Happily, the Gilbert White Field Studies Centre at Selborne is situated alongside The Wakes, which was White's home for most of his life and now houses the Gilbert White Museum.
Furnished in 18th-century style with some items of his own furniture, his first baby dress, and portraits of his family, the museum also contains the original manuscript of The Natural History of Selborne.
Attached is a shop filled with Selborne-inspired objects costing from a few pence to pounds. The field studies centre offers tailormade one-day courses and workshops for school groups throughout Hampshire, Surrey, Sussex and parts of London, designed as interaction between the pupils and their environment.
A single field study day at Selborne could embrace many course subjects: maths at junior level, measuring lengths, angles and time as the groups ascend the steep green woods to the top of Selborne Hanger, geology from local clay pits and brick works, river-studies, following the water courses White himself would have known, discovering perspective by "seeing" how houses and trees which look so large in the village appear tiny from a great height.
The new field studies building is situated in a 17th-century barn belonging to The Wakes, so is a useful point of departure for the study of buildings and building materials since that period, and there are also courses of comparative town and country studies.
These, as warden Jenny Streeter emphasises, "are not to show that the country is necessarily 'nicer' than the town, or vice versa, but simply to awaken the children to varying environments and their relationships to where they live. Then they are able to come to their own conclusions".
But always, everywhere, one can sense the be-wigged, knee-britched figure of White himself, ever-curious, sharp-eyed, listening, noting down an aurora borealis, a meteor, thick ice in June, glow-worms which appear to extinguish their lights at midnight and the appetite and adventures of his tortoise, Timothy.
Learning from White, the groups of children can begin to keep their own Selborne Journals, one of the many work and drawing books provided by the centre at the request of individual schools.
By visiting his home next door, and his garden - which displays so many of the plants he loved - by walking along the brick path to the ha-ha he built, and observing the fruits of the season growing on his old wall, they can enter the less pressured timewarp of the 18th century.
Best of all, if possible, they could take the "zig-zag path" he constructed beyond his grounds under the lee of Selborne Hanger, and climb up and up through the beech woods to Selborne Common.
Every twist and turn of the path is concealed by wild flowers and grasses, so that you feel totally isolated, until near the top, by the Wish Stone, you are rewarded with a magnificent view which shows the patchwork of meadow, stream and farmland rolling into the hollow palm of Selborne village.
In this lovely landscape, most of it the property of the National Trust and well marked for walkers, you feel that nothing moves; there is no sound. But you are mistaken. Arising from what you thought was silence is a delicate score of bird song, and in what you thought was stillness are the murmurings and rustlings and sudden glimpses of the inhabitants of that secret world which Gilbert White recorded so minutely day by day.
Gilbert White Field Studies Centre, The Wakes, Selborne, Near Alton, Hampshire. Tel: 01420 511303
* Gilbert White's House and Garden, tel: 01420 511275
* Gilbert White's Year: Passages from The Garden Kalendar and The Naturalist's Journal, edited by John Commander, with an introduction by Richard Mabey. Published by OUP