The joys of wavy walls

QUESTION Why are two-thirds of serpentine, or ‘crinkle-crankle’, walls in Suffolk?

Crinkle-Crankle walls are made from alternate convex and concave curves. Because of their sinuous shape, they are stable when built, just one brick thick, without the need for buttressing or wide footings.

Held together by soft, movable mortar, rather than rigid cement, these walls have sheltered landed estates and gardens for centuries. The idea appears to come from the

slangemuur ( snaking wall) in the netherlands, which has similar conditions to east anglia.

The first walls started appearing in east anglia in the 17th century, when Dutch engineers were draining the Fens and Dutch, brick-based architecture was becoming fashionable.

These high walls were particularly well suited to the exposed weather conditions of east anglia: they were stable on spongy ground found in reclaimed areas and were able to withstand winds and cold air.

Many of these grand walls are up to 50 bricks high. For decoration, some have a three- brick, herringbone patterned footing, while others are capped by halfbricks or rounds in a contrasting colour.

a by-product of the walls is that they have proved ideal for growing fruit trees. The concavities provide stored warmth from the sun and shelter from the wind for early flowering pip fruits.

Sir Christopher Wren installed a crinklecrankle at Wroxall abbey in Warwickshire, where he lived until his death in 1723. Curvy: A Suffolk crinkle-crankle wall Thomas Jefferson was so taken with the walls that when he retired from his third presidency of the U.S., he oversaw the building of a large linked system of crinkle-crankle walls encircling ten gardens at the University of Virginia.

Jess Petersen, King’s Lynn, Norfolk.

QUESTION When was the first patent issued in Britain and what was it for?

THe patent system was instituted in 1617 in the reign of James i. Patents were obtained through a system that required visiting seven different offices and two signatures from the monarch.

at the time, patents granted under this system were not numbered or published, but following the modernisation of the patent law in 1852, 14,359 patents granted up to that date were given numbers and published during the 1850s.

The first patent granted was awarded on March 2, 1617, for a method for engraving maps using metal plates: ‘a priviledge graunted to aaron rapburne, gent., & roger Burges, for terme of XXi years next, of the sole making, describing, carving & graving, all such and soe manie mappes, plotts or descripeons of lond. Westm. Bristoll, norwich, Canterbury, Bath, Oxford & Cambridge and the towne & castle of Windsor.’

The pair were subsequently awarded a royal grant to survey london and other cities. rathborne ( with a different spelling) also published an important early work on surveying, The Surveyor in Foure Bookes.

The Patent law amendment act of 1852 simplified procedure for obtaining patents, reduced fees and created one office for the entire Uk. J. K. Johns, Malvern, Worcs.

QUESTION Who invented the dialysis machine?

FUrTHer to the earlier answer, though Willem kolff invented the first dialysis machine in 1943, dialysis itself — the process of separating colloids from crystalloids — was developed by Glasgowborn chemist Thomas Graham (1805-69).

in 1861, he demonstrated the separation of suspended colloidal particles from dissolved ions (crystalloids) by means of their unequal rates of diffusion through semi-permeable membranes.

He used a parchment sack suspended in water, whereby the ions and small molecules passed through the membrane, leaving the colloidal particles in the sack. His ‘dialyser’ was a forerunner of modern dialysis machines.

Graham went on to become Professor of Chemistry at University College, london, and Master of the Mint. John Buxton, Chesterfield, Derbys.

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