Ha-ha

For other uses, see Haha.
Ha-ha protecting the lawn at Hopetoun House, West Lothian, Scotland. Note how the wall disappears from view as it curves away to the left of the picture.

A ha-ha is a recessed landscape design element that creates a vertical barrier while preserving an uninterrupted view of the landscape beyond.

The design includes a turfed incline which slopes downward to a sharply vertical face, typically a masonry retaining wall. Ha-has are used in landscape design to prevent access to a garden, for example by grazing livestock, without obstructing views. In security design, the element is used to deter vehicular access to a site while minimizing visual obstruction.

The name "ha-ha" may derive from the unexpected (i.e., amusing) moment of discovery when, on approach, the vertical drop suddenly becomes visible.

Origins

A comparison of a ha-ha and a typical wall

Before mechanical lawn mowers, a common way to keep large areas of grassland trimmed was to allow livestock, usually sheep, to graze the grass. A ha-ha prevented grazing animals on large estates from gaining access to the lawn and gardens adjoining the house, giving a continuous vista to create the illusion that the garden and landscape were one and undivided.[1][2][3] The ha-ha fit well with Chinese gardening ideas of concealing barriers with nature, but its European origins predate the European discovery of Chinese gardening.[4]

The basic design of sunken ditches is of ancient origin, being a feature of deer parks in England. The deer-leap or saltatorium consisted of a ditch with one steep side surmounted by a pale (picket-style fence made of wooden stakes) or hedge, which allowed deer to enter the park but not to leave. Since the time of the Norman conquest of England the right to construct a deer-leap was granted by the king, with reservations made as to the depth of the foss or ditch and the height of the pale or hedge.[5] On Dartmoor the deer-leap was known as a "leapyeat".[6]

Ha-ha at the Hameau de la Reine, Versailles.

The concept of the ha-ha is of French origin, with the term being attested in toponyms in New France from 1686 (as seen today in Saint-Louis-du-Ha! Ha!), and being a feature of the gardens of the Château de Meudon, circa 1700. The technical innovation was presented in Dezallier d'Argenville's La théorie et la pratique du jardinage (1709), which the architect John James (1712) translated into English:

"Grills of iron are very necessary ornaments in the lines of walks, to extend the view, and to show the country to advantage. At present we frequently make thoroughviews, called Ah, Ah, which are openings in the walls, without grills, to the very level of the walks, with a large and deep ditch at the foot of them, lined on both sides to sustain the earth, and prevent the getting over; which surprises the eye upon coming near it, and makes one laugh, Ha! Ha! from where it takes its name. This sort of opening is haha, on some occasions, to be preferred, for that it does not at all interrupt the prospect, as the bars of a grill do."

The etymology of the term is generally given as being an expression of surprise—someone says "ha ha" or "ah! ah!" when they encounter such a feature. This is the explanation given in French, where it is traditionally attributed to Louis, Grand Dauphin, on encountering such features at Meudon, by d'Argenville (trans. James), above, and by Walpole, who surmised that the name is derived from the response of ordinary folk on encountering them and that they were "... then deemed so astonishing, that the common people called them Ha! Has! to express their surprise at finding a sudden and unperceived check to their walk." Thomas Jefferson, describing the garden at Stowe after his visit in April 1786, also uses the term with exclamation marks: "The inclosure is entirely by ha! ha!"[7]

In Britain, the ha-ha is a feature of the landscape gardens laid out by Charles Bridgeman and William Kent and was an essential component of the "swept" views of Capability Brown. Horace Walpole credits Bridgeman with the invention of the ha-ha but was unaware of the earlier French origins.

"The contiguous ground of the park without the sunk fence was to be harmonized with the lawn within; and the garden in its turn was to be set free from its prim regularity, that it might assort with the wilder country without."[8]

During his excavations at Iona in the period 1964–1974, Richard Reece discovered an 18th-century ha-ha designed to protect the abbey from cattle.[9] Ice houses were sometimes built into ha-ha walls because they provide a subtle entrance that makes the ice house a less intrusive structure, and the ground provides additional insulation.[10]

Examples

Seen from the rear, the ha-ha at Castle Ashby blends into the landscape

Most typically, ha-has are still found in the grounds of grand country houses and estates and act as a means of keeping the cattle and sheep out of the formal gardens, without the need for obtrusive fencing. They vary in depth from about 0.6 m (2 ft) (Horton House) to 2.7 m (9 ft) (Petworth House).

An unusually long example is the ha-ha that separates the Royal Artillery Barracks Field from Woolwich Common in southeast London. This deep ha-ha was installed around 1774 to prevent sheep and cattle, grazing at a stopover on Woolwich Common on their journey to the London meat markets, from wandering onto the Royal Artillery gunnery range. A rare feature of this east-west ha-ha is that the normally hidden brick wall emerges above ground for its final 70 or so meters as the land falls away to the west, revealing a fine batter to the brickwork face of the so exposed wall - this final west section of the ha-ha forms the boundary of the Gatehouse[11] by James Wyatt RA. The Royal Artillery ha-ha is maintained in a good state of preservation by the Ministry of Defence, it is a Listed Building, and is accompanied by Ha-Ha Road that runs alongside its full length. There is a shorter ha-ha in the grounds of the nearby Jacobean, Charlton House.

In Australia, ha-has were also used at Victorian-era lunatic asylums such as Yarra Bend Asylum, Beechworth Asylum, and Kew Lunatic Asylum. From the inside, the walls presented a tall face to patients, preventing them from escaping, while from outside they looked low so as not to suggest imprisonment.[12] Kew Asylum has been redeveloped as apartments; however some of the ha-has remain, albeit partially filled in.

Ha-has were also used in North America. Only two historic installations remain in Canada, one of which is on the grounds of Nova Scotia's Uniacke House (1813), a rural estate built by Richard John Uniacke, an Irish-born Attorney-General of Nova Scotia.[13]

The Washington Monument is protected by a low ha-ha wall

A 21st-century use of a ha-ha is at the Washington Monument to minimize the visual impact of security measures. After 9/11 and another unrelated terror threat at the monument, authorities had put up jersey barriers to prevent large motor vehicles from approaching the monument. The temporary barriers were later replaced with a new ha-ha, a low 0.76 m (30-inch) granite stone wall that incorporated lighting and doubled as a seating bench. It received the 2005 Park/Landscape Award of Merit.[14][15][16]

In fiction

3D surface plot with a Ha Ha


In 3D surface plots

3D surface plots of f(x,y) functions with zero order discontinuities may exhibit ha-ha like features (see figure).

See also

References

Look up haha in Wiktionary, the free dictionary.
Wikimedia Commons has media related to Ha-has.
  1. ↑ West Dean College: "From the front the parkland landscape appears continuous, but in fact the formal grounds are protected from the grazing sheep and cattle by a ha-ha"
  2. ↑ "Lawn Pros and Cons". Pat Welsh. Retrieved 2013-04-15.
  3. ↑ Massachusetts Agriculture: "Early suburbanites relied on hired help to scythe the grass or sheep to graze the lawn. The lawn mower ... made it possible for homeowners to maintain their own lawn. ... The ha-ha provided an invisible barrier ... which kept livestock from wandering ... into gardens. "
  4. ↑ The first European attempt at a concerted account of Chinese gardening is Sir William Chambers, A Dissertation on Oriental Gardening, London 1772.
  5. ↑ Shirley, Evelyn Philip (1867). "1 Deer and deer parks". Some account of English deer parks: with notes on the management of deer. London: John Murray. p. 14. Retrieved 2012-11-24.
  6. ↑ Anon. "Okehampton Deer Park". Legendary Dartmoor. Retrieved 24 November 2012.
  7. ↑ The Papers of Thomas Jefferson Digital Edition, ed. Barbara B. Oberg and J. Jefferson Looney. Charlottesville: University of Virginia Press, Rotunda, 2008, p. 371. Online edition accessed 14 Aug 2012.
  8. ↑ Horace Walpole, Essay upon modern gardening, 1780
  9. ↑ Hamlin, Ann (1987). Iona: a view from Ireland. Proc Soc Antiq Scot, ISSN 0081-1564, V. 117, P. 17
  10. ↑ Walker, Bruce (1978). Keeping it cool. Scottish Vernacular buildings Working Group. Edinburgh & Dundee. Pages 564-565
  11. ↑ Large and Associates website
  12. ↑ Kew Lunatic Asylum - Historic Walk Australian Science Archives Project, [Kew Lunatic Asylum]
  13. ↑ Anon. "About Uniacke Estate". Nova Scotia Museum. Retrieved 14 October 2015.
  14. ↑ Washington Monument (from the OLIN website)
  15. ↑ Monumental Security (from the American Society of Landscape Architects website, April 10, 2006)
  16. ↑ "Risk Management Series: Site and Urban Design for Security, , page 4-17". U. S. Department Security, Federal Emergency Agency.
  17. ↑ Annotations from Terry Pratchett's Men at Arms (from The Annotated Pratchett File v9.0
  18. ↑ Terry Pratchett - Snuff (2011) page 56. (Corgi Books ISBN 978-0-552-16675-1)
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