Windmills and Waterwheels Explained , livre ebook

Countryside Books - Stan Yorke

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132 pages

English

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Waterwheels provided our sole source of power, apart from animals and our own sweat, as far back as 200 BC. Windmills arrived in the 12th Century and then both reigned supreme until the appearance of the steam engine during the 18th Century. This vast timespan made them key elements of our history. But do we know what they do and how they work? Stan Yorke sets out to explain just that, using easy-to-follow text and with extensive drawings, diagrams, and photographs. The book describes the various styles of mill, and the process of grinding down grain to produce flour. It looks too at the way the energy from a waterwheel or a windmill's sails is used to power the machinery itself. The explanations and illustrations are linked directly to mills that we can still see today. Fortunately, there are some 400 restored mills, and some even produce flour for sale. The book includes a list of these sites, plus a glossary of unfamiliar terms.

Sujets

Sciences et techniques

Reino Unido

United Kingdom

History of Europe

Great Britain

Royaume-Uni

Informations

Publié par	Countryside Books
Date de parution	12 octobre 2006
Nombre de lectures	0
EAN13	9781846748585
Langue	English
Poids de l'ouvrage	2 Mo

Informations légales : prix de location à la page 0,0374€. Cette information est donnée uniquement à titre indicatif conformément à la législation en vigueur.

Extrait

WINDMILLS and WATERWHEELS EXPLAINED
What They Do and How They Work

STAN YORKE
First published 2006 © Stan Yorke 2006
All rights reserved. No reproduction permitted without the prior permission of the publisher:
COUNTRYSIDE BOOKS 3 Catherine Road Newbury, Berkshire
To view our complete range of books, please visit us at www.countrysidebooks.co.uk
ISBN 1 84674 011 8 EAN 9781 84674 011 4
Photographs and line illustrations by the author
Produced through MRM Associates Ltd., Reading Typeset by CJWT Solutions, Newton-le-Willows Printed by Borcombe Printers plc, Romsey
C ONTENTS
A CKNOWLEDGEMENTS
I NTRODUCTION
SECTION I

T HE S TORY OF M ILLING
Chapter 1
A B RIEF H ISTORY
Chapter 2
S CIENCE AND I RON A RRIVE 1700–1800
Chapter 3
T HE Z ENITH OF L OCAL M ILLING 1800–1850
Chapter 4
F ROM F RONT L INE I NDUSTRY TO L ONELY B ACKWATER
SECTION II

I NSIDE THE M ILL
Chapter 5
M ILLING
Chapter 6
T URNING THE S TONES
Chapter 7
T HE O THER A PPLICATIONS
SECTION III

R ESTORED M ILLS TO V ISIT
Chapter 8
T HE S CENE T ODAY
S ITES TO V ISIT
G LOSSARY
I NDEX
Acknowledgements

D uring the research for this book I have been delighted by the enthusiastic help and advice I have received from the staff and helpers at numerous mills. Possibly because many are run by part-time ‘amateurs’, they are only too happy to talk about their mill and its restoration and running. Whatever the reason, I thank you all for your patience and interest.
My particular thanks go to Martin Hanson of Heckington Windmill for reading through the draft and making comments and corrections. Lastly, and by no means least, I must thank my wife, Margaret, for her endless patience whilst I disappeared for hours working on the book.

Woodbridge Tidemill.
Introduction

I t is amazing to discover that there are well over 400 waterwheels and windmills open to the public in England and Wales, many of them still working. It is as though (secretly placed around the countryside) there are portals to a time, not just a century or two ago, but back a thousand years or more.
It was whilst researching for my book The Industrial Revolution Explained that I came across the superb work of modern-day restorers in bringing back to life these ancient machines. Like many early working machines these have blended completely into the countryside and, I suppose, because they feature in every turn of our history they seem to be natural features – hardly man-made at all.
But what of their history and how do they work? In keeping with the rest of the ‘England’s Living History’ series of books, I have set out to explain the background and development of both waterwheels and windmills without recourse to overly technical terms. Indeed, part of their charm is their deceptively simple mechanisms which hide a great deal of knowledge and ingenuity.

One of the few industrial sites still active – Cheddleton Flint Mill in Staffordshire.
This link to the past is not all that it seems, though. Look at a windmill or watermill today and for all the world it could have been unchanged for centuries. This, however, is not quite true! These are working machines, they were virtually our only industrial power source from the Roman occupation until the arrival of steam in the 1700s and, like all industrial processes, they were updated and rebuilt as new ideas arrived. What we see today are mostly mills from the late 1700s and early 1800s that have been lovingly restored, often from complete dereliction. Unlike castles and houses which still stand, the link with early times lives on in the sites and occasionally in the materials. In many cases, there has been a mill on the site right back to medieval times, particularly watermills.
The book is split into three sections. Section I provides an overview of the mills from the earliest times right up to their demise in the 19th century. In Section II we get our hands dirty and look in detail at the processes and workings of the mill machinery. In order to simplify what at first can seem a bit chaotic I have discussed the turning of grain into flour in chapter 5 and in chapter 6 I have shown the mechanics of the drive systems and how the power from the sails or wheels gets to the stones. Section III brings us up to date with the work of restoration and the latest uses of wind and water power. It then gives some thought to finding mills to visit, plus giving a glossary of terms.

Derbyshire mill stones resting after many years of work, at Daniels Mill near Bridgnorth in Shropshire.
You will note a very heavy bias towards flour milling because, quite simply, this activity is by far the most common in the restored mills we can see today. Where I have come across working sites that illustrate some of the other uses that windmills or waterwheels were put to, I have included a picture and notes.
The book is generously illustrated with photos and drawings and will, hopefully, arouse your interest and add to the enjoyment of visiting.
Stan Yorke

The basic types of windmills and waterwheels .

Classic post mill with bricked-in base timbers at the Avoncroft Museum of Historic Buildings. The post with the wheel at the end is used to turn the mill into the wind.
S ECTION I

T HE S TORY OF M ILLING
C HAPTER 1
A Brief History

L ike so many early features in history, our knowledge is based on the distilled comments and interpretations of many different chroniclers. This leads to a variety of opinion that can seem difficult to resolve and indeed this confusion is very true of our earliest machine – the waterwheel.
What seems generally agreed is that man used the flow of water in a river or stream to power simple mechanisms at least as long ago as 200 BC. There are three basic devices that are known from early Roman times: the horizontal waterwheel, often called a Norse wheel; the Noria; and the undershot vertical waterwheel. Some claim the Norse wheel comes from earlier centuries in Greece but others suggest that the evidence for this is very weak. Indeed, some suggest that it might well have come last of the three. What we do know is that all three machines were widely used and survived in various forms into the 19th century, with a few making it into the 20th century.
The horizontal wheel consisted of a vertical shaft around the bottom of which were fixed radial boards or paddles. The water flow was directed at these paddles so that it caused them, and the shaft, to rotate. The rotating shaft was used to directly turn a grindstone to make flour.
The very earliest versions adjusted the gap between the grinding stones (a feature, as we shall see, that was very important) by a system of wedges set into the shaft, but very soon this was replaced by the ‘tenter beam’ or ‘bridge tree’, as shown in Fig 1.1 . This beam carries the bottom bearing of the vertical shaft including the paddles and the top ‘runner’ stone. By adjusting one end of this beam the top stone can be raised or lowered, thus altering the gap between the stones, a process known as tentering. These wheels were relatively simple to construct and could also turn a modest-sized grindstone using very little water flow. Its simplicity made this type of wheel common in small rural communities and some were still in use up to the last century in Scotland and Ireland.

FIG 1.1: Possible arrangement of an early horizontal wheel flour mill. The arrangement of the stones and the way the grain was fed had been established by the Romans and remains virtually unchanged to this day. This type of wheel became known popularly as a Norse wheel.
The vertical wheel is the type we think of as the traditional water wheel. The paddles are set on a much larger diameter than the Norse wheel and the shaft that holds them is horizontal, carried in two bearings. The Noria was a variation of the vertical wheel used to lift water and was a self-contained machine that did not drive anything else. It consisted of a wheel which carried around one side a series of pots or buckets. The bottom and the lowest pots were in the flow of a river, which turned the wheel.
The pots filled with water at the same time and were carried, rather like a big wheel at a fairground, up to the top where they would empty their contents into a trough, which carried the water away. Used for irrigation and water supplies to towns, they were built to surprisingly large diameter – certainly up to 50 ft (15 m) and possibly larger.
Roman engineers developed a variation on this theme, where they devised an undershot wheel to turn a separate ‘chain of pots’. This used water containers, sometimes earthenware pots, sometimes wooden boxes, which were strung together to form a continuous loop. The bottom of the loop dipped into the river and the top tipped the water-filled pots into a wooden channel, thus directing the water as required. They were normally driven at the top and thus required gears and shafts from the waterwheel, so not only could they be used to raise water from a river but the same ‘chain of pots’ could be driven at the top and used to lift water up from a shaft or mine.

FIG 1.2: This figure shows the principle of the Noria. The pots are held out from the wheel in order to pass over the receiving trough. There are quite a few drawings of what historians believe the Noria may have looked like but, alas, many are not mechanically feasible!
The main use of the traditional vertical wheel was always to turn grindstones to make flour, though the rotating horizontal shaft of these waterwheels could also power hammers and certainly it was used to crush stone from the very beginning. The horizontal shaft, however, is no use for grinding flour and here the breakthrough almost certainly came from the Romans – gears.
The first gears were used simply to take the power from the rotating horizontal shaft and turn it through 90° to drive a verti