Specification of Thomas Paine
A.D. 1788. No. 1667.
CONSTRUCTING ARCHES, VAULTED ROOFS, AND CEILINGS
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS PAINE, send greeting.
WHEREAS, His Most Excellent Majesty King George III, by his letters patent under the Great Seal of Great Britain, bearing date the twenty-sixth day of August, in the twenty-eighth year of his reign, did give unto me, the said Thomas Paine, his special license that I, the said Thomas Paine, during the term of fourteen years therein expressed, should and lawfully might make, use, exercise, and vend, within England, Wales, and Town of Berwick-upon-Tweed, my invention of "A METHOD OF CONSTRUCTING ARCHES, VAULTED ROOFS, AND CEILINGS, EITHER IN IRON OR WOOD, ON PRINCIPLES N E W AND DIFFERENT TO ANYTHING HITHERTO PRACTISED, BY MEANS OF WHICH CONSTRUCTION, ARCHES, VAULTED ROOFS, AND CEILINGS MAY BE ERECTED TO THE EXTENT OF SEVERAL HUNDRED FEET BEYOND WHAT CAN BE PERFORMED IN THE PRESENT PRACTISE OF ARCHITECTURE; "in which said letters patent there is contained a proviso obliging me, the said Thomas Paine, to cause a particular description of the nature of my said invention, and in what manner the same is to be performed, by an instrument in writing under my hand and seal, to be enrolled in His Majesty's High Court of Chancery within one calendar month next and immediately after the date of the said recited letters patent, as in and by the same (relation being thereunto had) may more fully and at large appear.
Now KNOW YE, that in compliance with the said proviso, I, the said Thomas Paine, do hereby declare that my said invention of A Method of Constructing of Arches, Vaulted Roofs, and Ceilings, either in Iron or Wood, on Principles New and Different to anything hitherto practised by means of which Construction, Arches, Vaulted Roofs, and Ceilings may be Erected to the Extent of several Hundred Feet beyond what can be performed in the present practise of Architecture, is described in manner following (that is to say) :-
The idea and construction of this arch is taken from the figure of a spider's circular web, of which it resembles a section, and from a conviction that when nature empowered this insect to make a web she also instructed her in the strongest mechanical method of constructing it.
Another idea, taken from nature in the construction of this arch, is that of increasing the strength of matter by dividing and combining it, and thereby causing it to act over a larger space than it would occupy in a solid state, as is seen in the quills of birds, bones of animals, reeds, canes, etc. The curved bars of the arch are composed of pieces of any length joined together to the whole extent of the arch, and take curvature by bending.
Those curves, to any number, height or thickness, as the extent of the arch may require, are raised concentrically one above another, and separated, when the extent of the arch requires it, by the interposition of blocks, tubes, or pins, and the whole bolted close and fast together (the direction of the radius is the best) through the whole thickness of the arch, the bolts being made fast by a head pin or screw at each end of them. This connection forms one arched rib, and the number of ribs to be used is in proportion to the breadth and extent of the arch, and those separate ribs are also combined and braced together by bars passing across all the ribs, and made fast thereto above and below, and as often and wherever the arch, from its extent, depth, and breadth, requires. When this arch is to be applied to the purpose of a bridge, which requires more arches than one, they are to be connected in the following manner (this is to say):
Wood piles are to be driven into the earth; over each of those piles are to be let fall a hollow iron or metal case, with a broad foot let into a bed; the interspace between the case and the wood pile to be filled up with a cement and pinned together. The whole number of those pillars are to be braced together, and formed into a platform for receiving and connecting the arches. The inter spaces of those pillars may be filled with plates of iron or lattice work so as to resemble a pier, or left open - so as to resemble a colonnade of any of the orders of architecture.
Among the advantages of this construction is that of rendering the construction of bridges into a portable manufacture, as the bars and parts of which it is composed need not be longer or larger than is convenient to be stowed in a vessel, boat, or wagon, and that with as much compactness as iron or timber is transported to or from Great Britain; and a bridge of any extent upon this construction may be manufactured in Great Britain and sent to any part of the world to be erected. For the purpose of preserving the iron from rust it is to be varnished over with a coat of melted glass. It ought to be observed that extreme simplicity, though striking to the view, is difficult to be conceived from description, although such description exactly accords, upon inspection, with the thing described.
A practicable method of constructing arches to several hundred feet span, with a small elevation, is the desideratum of bridge architecture, and it is the principle and practicability of constructing and connecting such arches so as totally to remove or effectually lessen the danger and inconvenience of obstructing the channel of rivers, together with that of adding a new and important manufacture to the iron works of the nation, capable of transportation and exportation, that is herein described. When this arch is to be applied to the purpose of a roof and ceiling cords may be added to the arch to supply the want of butments, which are to be braced to or connected with the arch by perpendiculars.
In witness whereof, I, the said Thomas Paine, have hereunto set my hand and seal, the twenty-fifth day of September, in the year of our Lord one thousand seven hundred and eighty-eight.
THOMAS (L.S.) PAINE.
Sealed and delivered, being first duly stamped, in the presence of PETER WHITESIDE.
that on the twenty-fifth day of September, in AND BE IT REMEMBERED, the twenty-eighth year of the reign of His Majesty, King George, III, the said Thomas Paine came before our said Lord the King in His Chancery, and acknowledged the instrument aforesaid,, and all and everything therein contained and specified, in form above written. And also the instrument aforesaid was stamped according to the tenor of the several statutes made in the sixth year of the reign of the late King and Queen, William and Mary of England, and so forth, and in the seventeenth and twenty-third years of the reign of His Majesty King George III.
Enrolled the said twenty-fifth day of September, in the year last above written.