The Old Mill

This weekend is National Mills Weekend when windmills and watermills across the country are opened up to the public. Bourn Windmill is by no means the largest or most impressive mill in the land but is of interest to me because some of my ancestors lived and farmed in Bourn and must have been familiar with its turning sails. (This is Bourn, Cambridgeshire, not the more famous one in Lincolnshire). Small mills like this were the norm across the country, though most were put out of business as larger, more efficient mills took over.

Technically it's an "open trestle post mill" which is one of the earliest kinds of mill known. The "trestle" is the triangular section at the bottom which supports the mill and which in later mills is enclosed. And it's a "post mill" because the whole mill above the trestle rotated upon a single huge oak post. What's more it still rotates today....

Despite appearances it turns very easily and smoothly and, although lots of visitors volunteered to help, I'm sure that a single sturdy miller could move it on his own. The reason for rotating the mill was to ensure that the sails were always pointing into the wind.

So just how old is this mill? Well, we know it was here in 1636 and that was thought to make it the oldest post mill in England. However the very similar mill, just down the road at Gransden, has had its central post dated at 1620 so may be a little older. The design of the mill is even older than that; looking online I found this thirteenth-century century illustration...

Not the greatest scale drawing but the general idea seems to be there. Lets go and look inside the real thing...

Here on the lower floor is where the flour was bagged off. I'd love to be able to show you more details from inside but there's not a lot of space or light in there. Then I noticed that the central post had begun to slowly rotate...…????

The explanation was that another enthusiastic group of visitors had arrived and it was the whole mill that was turning around the central post which was of course stationary. But the movement was so smooth that there was no vibration whatever to be felt by those of us in the mill. Medieval engineering at its best!

Upstairs (or more accurately "up-rickety-wooden-ladder") we could see the huge millstones that ground the flour. The chute coming in from the bottom left of the photo delivered the grain into the centre of the millstones, where it fell down and was ground between the rotating stone and the stationary one beneath. 

We were standing around the trap door through which the sacks of grain were hoisted up (using power from the turning sails, of course). The central shaped piece of wood has been inserted recently to fill the gap which has been worn away by the chains that hoisted the sacks.

Behind us were more workings that it's thought would have turned a second set of millstones. It was in these cramped and downright dangerous conditions that the miller and his boy would spend their working days - and nights too if there was sufficient wind.

With the tour completed we went to enjoy tea and cakes, and perhaps to contemplate the events of a windy night in 1741 when the miller, Richard Bishop, went out to adjust the mill. Part of the mill was blown down by the storm, killing the unfortunate miller.

(Bourn Windmill is also open once a month during the summer months see website for details).


Take care.