Thomas Jefferson Papers

To Thomas Jefferson from Thomas Bruff, 21 March 1808

March 21st 1808. Six buildings


I am persuaded that any attempt to call your attention, at this interesting period of our publick affairs, to any thing I could produce, needs an apology and the only one I am able to offer, arises out of the present situation of the country, and the necessity there will shortly be of exerting mechanical talents, which I hope will yet find encouragement in a land so favourable to thier compleat success.

Since I took the liberty of addressing you on a former occasion, I have produced, besids some smaller maters, two things which I think of some moment to the public, a new fire engine, intirely different from any thing I have seen or heard of; and a permanent horizontal wind mill, capable of moving machinery of any burden.

I have witness’d the deficiency of engines in several instances, ob[. . .] with astonishment—what labour was applied, and to what little pu[. . . .]. At that time I had never seen or had a description of thier inside works, but adjusted a plan in my mind, of such a machine as I supposed ought to be used, and if used, could not immagine how such labour could be necessary. After commiting the outlines of my plan to paper, I got an opportunity of examining one in this city, and to my surprize, found not only the principle entirely different from mine, but many more obstructions than I could have had an idea of. I look’d at it with amazement, and could not immagine how it was, that in so old an invention the defects had never been discover’d. I then examined the Enciclopedia, but finding nothing in the cuts like mine, determined further to consider and mature my plan, till some fortunate circumstance, (if such ever occur’d.) should enable me to execute it to my mind. The lever of the smallest I have seen, measures 40 inches from the pevet on which it turns, to the extremity; in such an one, I gain 9 inches, in the application of force, which is 2/9ths of the whole, an advantage I think worthy of attention, but I have others that are more than equal to it Viz. applying the force in a right direction, removing obstructions to the course of the stream, condensing the water gradually, and preventing the danger of choaking.

I have made a windmill in miniature, on my plan, 21 inches diameter, which when placed in the wind, goes so fast the sails could scarcely be seen, if they were not white. They are defended from the weather; there is no counteraction from the wind, as it can only act where it is wanted. It recieves the blast as well from one quarter as another, the force can be increased or diminish’d to almost any degree, and is so perfectly manageable without reefing, as to accommodate it in a few seconds to the rising and falling of the wind in variable weather. Being moved by the application of two levers or arms at the same time, its motion is so uniform and steady, as to fit it, in the opinion of the best judges, for the manufactory of flour, sawing timber of any size, or for working machinery of any kind. Ten or twelve feet squair of canvass spread full to the wind, like the taut sail of a vessel, will give great force; and that force may be increased by enlarging the sails or lengthening thier levers, as my calculation is only made to 24 feet diameter. I should take much pleasure in laying my plans before you, if an opportunity should present itself that would make it agreable to you.

I am verry respectfully Your Hl. Servt.

Thos. Bruff

DLC: Papers of Thomas Jefferson.

Index Entries