A traditional windmill has a set of sails attached to an approximately horizontal windshaft, so when the wind acts upon the sails, they rotate in a vertical plane. There is one particular disadvantage to this arrangement that has occured to multiple inventors througout the ages - in order to work, the mill has to be made to face towards the wind direction.
So they reason, why not design a windmill where the sails rotate in the horizontal plane, (and thus around a vertical axis). As long as you can arrange it so that the wind only acts on one side of the axle, then it doesn't matter which direction it comes from - it will create a rotational force.
In fact the earilest mills were probably simple horizontal mills - as evidenced by some of the remaining Persian windmills.
Of course, nothing is that simple - as well as it being problematic to ensure that half of the area swept by the sails is blocked off from the wind, the horizontal windmill also has to support the whole of the weight of the sails on a single bearing at the base of the shaft. That bearing also has to resist the lateral forces that the the wind is causing on the structure - so there are considerable mechanical issues to be solved.
The most celebrated builder of horizontal windmills in England was Captain Stephen Hooper, who patented a design, and built a number of examples including at Battersea and Margate.An enquiry about powering a lathe with a horizontal wind engine: Mechanics Magazine Vol 4, 1826
An brief, yet innacurate, description of the mill at Battersea: Mechanics Magazine, Volume 4, 1826
No 145 Wind LATHE
SIR - Having a workshop in the centre of a town, and in which I have a Lathe, which I wish to work by sails, on the principle of a windmill, but which must have the sails in a horizontal position, I wish to know how this would act; and will thank any of the contributors and Correspondents to your Magazine to favour me, through its medium, with a plan or description of this sort of wind-engine. I should wish the description to state how many arms there should be, and whether every other arm should dip or not, to catch the wind better. Any other information on the subject either derived from personal experience, or from books, or otherwise, will be very acceptable, as I never saw a movement of this description.
I remain Sir, Your very obedient servant E.B. Cabinet maker. Skipton, near Craven.
This was answers by a general memoir about the inventor: Mechanics Magazine, Volume 5, 1826
No 145 WIND LATHE
SIR - If your Correspondent, "E. B." is in the habit of visiting London, he may see a beautiful horizontal mill at Battersea. The sails consist of a large wheel, exactly like an undershot waterwheel, only much longer in the direction of the axis; this is placed with its axis vertical and is provided with a semi cylindrical case, revolving about the same axis, the diameter of which semi cylinder is adjusted to coincide with the direction of the wind. Thus one half the sails are exposed to the wind, and one half sheltered, and a rotatory motion is produced.
I am Sir Yours respectfully F. O. M.
BATTERSEA MILL - MEMOIR OF THE INVENTOR CAPTAIN STEPHEN HOOPER
SIR In Number 109 page 399 of your interesting Miscellany, a Correspondent has called the attention of your readers to the beautiful Horizontal Mill at Battersea. This circumstance has revived in my mind some pleasing recollections of the years that are past, when I numbered the inventor of that ingenious piece of mechanism among my most valued and excellent friends; and it has also suggested the idea that a short memorial of him and some of his inventions might not be unacceptable to the readers of the Mechanics Magazine.
The mill at Battersea was built under the direction of the inventor and patentee, Capt Stephen Hooper, a native of Sandwich in Kent. He was brought up to the sea and for many years commanded a West Indiaman chiefly in the Antigua trade. During his voyages he was in the habit of amusing his leisure hours in mechanical employments, and, like some of your Correspondents, was once so certain that he had discovered the perpetual motion, that, at dinner-time he declared that he would not take ten thousand for his invention, but before bedtime he had discovered that it not worth that number of farthings. In his horizontal mill he found more solid advantage; for having left the sea and built a mill of this kind at Margate, he and his sons carried on for many years an extensive business in the flour trade.
Though the horizontal mill is cetainly a very ingenious contrivance, and probably allows of the application of wind, as a moving power, to a greater extent than any other machine, yet it has the same defect its structure as the water wheel, to which its interior bears a strong resemblance.
There is a considerable loss of power in consequence of the floats, or, as Mr Hooper called them, the flyers, moving before the impelling force, and, therefore being acted on according to the relative and not the actual velocity of the wind. Few of these mills have been erected, probably owing to the expense of so lofty a structure; which, if not built with great care and skill, like that at Battersea, will be extremely liable to injury.
There were other inventions of Captain Hooper, which have rendered this most excellent and ingenious man a benefactor to the mechanical and manufacturing part the community. He was the inventor of those vanes for wind-wills which contract or extend the clothes in proportion to the increase or diminution of the wind. The same object has since been accomplished by means differing from those he employed, but the thought and exe[cu]tion were originally his.
But there is another invention of Mr Hooper's, which has been introduced into almost every piece of machinery whose moving power is subject to changes affecting the velocity of the engine.
When Mr Hooper first entered on the mealing business, it was esteemed necessary to have a man to superintend every pair of stones, and to adjust, by the screw, their distance, according to the ever varying motion of the wind-mill. Though not yet well acquainted with the niceties of the flour manufacture, he was convinced that this service might be performed more accurately and more economically by the mill itself. It was, however, long before he could accomplish his object; accident at length led to the completion of his wishes. Walking in the neighbourhood of Ramsgate, he picked up a stone, and having tied it in the corner of his handkerchief, he was amusing himself by giving it a rotatory motion parallel to the horizon, when he observed that in proportion to its velocity, it endeavoured to extend its orbit, and to rise to a level with his hand. This immediately suggested the idea of the flying balls, which not only answered the purpose sought by Mr Hooper, but have become an almost universal regulator of motion in every species of machinery. The discovery would probably have been productive of considerable pecuniary advantage to him, had he not been most dishonourably deprived of his patent by a counter claim to the invention, advanced by a person resident in the same place; and who, I was told, was afterwards discovered to have bribed one of Mr Hooper's workmen to allow him to look through the key hole of the private room, in which was situated the regulator that governed the five pair of stones in the horizontal mill.
In the time of scarcity which occured about the year 1801, Mr Hooper met with some very unpleasant circumstances, from the unquiet spirit which is always manifested by John Bull when he is either hungry, or fears he shall be so. On one occasion, it was only by the prompt exertions of a body of cavalry that Mr. H. and his family were preserved from destruction. Upon this he offered the use of his mills to the Magistrates for the convenience of the town, but declined business on his own account, as having become both unprofitable and dangerous. Shortly after this he sold his property at Margate, and went to reside at Walworth near London, where for some time he pursued his mechanical amusements and formed many very ingenious and interesting models, which, from his situation and time of life, he never had the opportunity of applying to any useful purpose. He died at a very advanced age, leaving in the breasts of all who knew him, a most pleasing remembrance, not only of his mechanical genius but of the more important qualities of ardent piety and genuine benevolence.
To return to the horizontal mill. Your Correspondent has very accurately represented the internal mechanism, by comparing it to a large water-wheel whose shaft is perpendicular to the horizon; but if he will more clearly inspect the exterior, he will find his idea relative to the "semi cylindrical case revolving about the same axis" quite erroneous. The exterior is a circle exactly similar to a Venetian blind, each shutter being capable of being brought into contact with its neighbour, so as to exclude the wind entirely; or of being so opened as to admit a full breeze to fall upon the flyers, or floats of the internal wheel. It is evident that one side of this structure will admit the current of air, while the other will be impenetrable; and that this will be the case, let the wind change in any direction whatever. By a very ingenious contrivance, Mr Hooper at first enabled the mill to regulate its own velocity, by closing or opening the shutters as the wind increased or diminished its force. But as this machinery was apt to get out of order, he discontinued the use of it in his own mill and left the regulation of the speed to the vigilance of the workmen.
I am Sir Your obedient servant Q.
In the name of God Amen
I Stephen Hooper [xxxxxx] of Margate in the parish of Saint John the Baptist in the Isle of Thanet in the county of Kent but now of [xxxxxxxxx] in the county of Surrey, [xxxx] being of sound [xxxxx] mind and memory do make public and [xxx] this my last will and testament in [xxx] form following that is to say
SIR, - In the 114th Number of your valuable Miscellany, there is a drawing and description of a Horizontal Windmill by T.T., who probably thinks that the idea is a new one, which, however, is not the case; for, about nine years ago, I made a similar one on a small scale, with this difference, that I fixed a large flat piece on the top of the upright shaft, on which the arms lay, one crossing over the other at right angles, and secured to it with collars, in which they might revolve freely in a vertical direction. The vanes, instead of being attached to the arms with hinges, as T.T.’s, were firmly secured at right angles to each other; or, in other words, if the vane at one end of each of the arms hung perpendicularly downwards, those at the opposite ends would be horizontal, and vice versa. It is therefore evident, that whichever vane catches the wind, it is forced downwards towards the perpendicular, and in that position recedes, and is succeeded by the next; while that at the opposite end of the arm, as before-mentioned, is by the same action borne upwards towards the horizontal, thereby offering but a trifling resistance in advancing to that point where it preponderates, catches the wind, and assumes the perpendicular in its turn.
I applied it to a boat with paddlewheels, with a view of propelling it against the wind—an object that I have no reason to think unattainable, although it failed with me at that time, owing to the horizontal revolution of the sails giving a tendency to the vessel to wheel round in the water in the same direction; I therefore gave up the experiment, with the intention of attempting it at some future time in another form, by making use of two sets of sails, one over the other, made to revolve contrariwise, by which means the tendency given to the vessel to wheel about by one set, would be neutralized by the contrary tendency given to it by the other. . This, though I still think it practicable, is mere theory, as my other avocations have not afforded me leisure sufficient to bring my intended experiment to the test, necessary to form an accurate judgment of its claim to further consideration and improvement.
I am, Sir, Your very humble servant, S_____, L__q__p__d-street.
Mechanics Magazine, Volume 5
SIR, - In Number 113 of your valuable Publication, there is a description given of a Wind-Lathe, or what I should rather call a Horizontal Windmill, by a person signing himself "R. H." Conceiving that such a power might with advantage be aplied to actuate a two-horse threshing machine, I constructed a model on R. H.’s principle, and, as far as that goes, find it answer my fullest expectations; but knowing how defective those are in general, when compared with the actual engine, and that many have been led into serious losses by supposing that the machine, in its full size, will work equal to the model, I have deferred any farther proceedings until some more particular description shall be afforded by R. H., which in the article he has promised to do. R. H. will confer a favour, if he will give a more accurate description of the several parts of the machine; viz. what should be the length and depth of the arms or wings; the breadth of the narrow strips of board to act in the manner of a Venetian blind, the height the arms or wings should be elevavted above the ground, so as to obtain a sufficient power from the wind; the whole calculated to work a threashing-machine of three or four horse power, with fanners, &c. attached to if for cleaning the corn.
The above being inserted in your next publication, will oblige a constant subscriber.
SIR, - I fear that I shall not be able to answer satisfactorily the questions proposed by N.W.G., in a late Number, but I feel it necessary to say a few words on the subject, in explanation of my promise to give further information.
The whole of my knowledge - if it can be said to be knowledge - of the good or bad properties of the Horizontal Windmill, which I attempted to describe in No. 113, depends upon theory; I have never seen any thing of the kind put in practice. It appeared to me to be an improvement on the plan previously described by Clio, in No. 98; and all that I could have then said, or can now say, more than is stated in my first communication, would be to point out wherein this improvement consisted. If the principle be good, of which I have no doubt myself, and which the model made by N. W. G. seems to prove, the minor matters, as to length of arms, height, &c. may be left to the judgment of the builder, to be regulated according to the quantity of work required to be done, and the situation in which the mill or lathe may be erected. On the top of a hill, or on an open plain, the elevation of the arms need not be great; but, in partially confined situations, the building must, of course, be high. In this respect it would be like the common windmill.
I am fond of experiment, and had I the means, which I have not, I would make a good-sized model, in order to convince myself of the effect produced by the horizontal arms. Were I to have the direction of putting up a mill on this principle, to do a given quantity of work, I should calculate as near as I could as to the surface necessary to each arm, by a comparison with mills on the old principle, but at the same time making the arms in such a manner that I could easily either lengthen or shorten them. The necessary extent of surface may be thus obtained without any great trouble or expense. I know of no other way: the wind seems too variable in its effective power to allow of any thing like accurate calculation to be built upon it. It is necessary that the arm should have sufficient surface to do the required work with the aid of a moderate wind; and it is necessary also that this surface be easily contractible when the wind is more fresh. This I should think may be done by some easy means of fastening (either open or closed will do) any number that may be required of the windboards. The breadth of the wind-boards is but of little importance, and may be made to suit the taste or the convenience of any one who may adopt the plan. The height of the mill should be regulated by the situation, the favourable or unfavourable circumstances attending which may be easily ascertained.
The above are not answers to the questions of N. W. G.; they are merely hints on which he or others may perhaps improve.
I should be happy in being favoured with N. W. G.'s address. I trust that I shall not offend. If he will leave his address with the Editor of the Mechanics’ Magazine, directed to R. H., he will oblige me. I shall be in London during the coming Spring, and should N. W. G. live in or near, and have no objection, I should feel happy in having a sight of his "model."
I am Sir, Your Obediant Servant, R___ H___.
|Last updated 27/07/2020||Text and images © Mark Berry, 1997-2020 -|