Extracts from Bt. Lt. Col. S.H. Longs' pamphlet on his patent bridges Concord N.H. 1836	b
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The improvements under consideration consist of the Patent cfff following modifications or arrangements, inthe construction March 6th of the main longitudinal truss frames necessary too the form-1830	matinn and support of a bridgw, viz;
1st. Two modes of splicing the string pieces, one by means of wooden, and the other 'by means o'f"'4ron splicang pieces, of a construction different from any heretofore adopted in
bridge architecture.
2nd. A system of bracing, by means of which, the truss frame are exempted from leverage in every iM nnci.nt Ininn liable to be efected by such an action, and the stresesor thrusts com-muhicated by the braoes, are resisted by shoulders or steps as nearly asrnay be at right angles with the grain, or fibres of the timber.
3d. A system of counter bracing, by means ofwhichthe truss frames are rendered stiff and unyielding, and the bridge kept in uniform action, whether loaded or unloaded. 4th.A mode of furnishing the main braces and posts with metallic bearings, by the introducton of thin plates of iron copper or other suitable metal, between the toe and heel of each main brace, and the staps in the posts against which they thrust, and
5th. A mode of keying or wedging, by means of whichthe central parts of the truss frames, and consequently of the brig dge , may be elevated andsustained, in case of subsidence or sinking of those parts, which is liable to happen fromashriia kage or extraordinary compresion of the timber. These several improvements which are claimed as new , useful and original, together with avariety of other arrangements many of which are believed to be unprecedented in bridge arh hitecture, will be more- fnil frp clearly illustrated by the drw ing and Explanatory references hereto annexed, and exhibited under thedesignation of the Jackson Bridge " Patent of Jan. 23d. 1836
" The object of these improvements is to produce and ensure latteral stiffness or inflexibility in wooden or Frame bridges, which object is effected by meansof a plan or system of bracing applied either to the upperorthe lower strings of the bridge, or to both should it be deemed advisable, whichplan or system I shall designate by the name of the lattice Bracing, and which is of the following description; k^tice Bracing consists oftimbers of suitable
dimensions,(about 3 by 9 to 12 inches transversely, and of any appropriate length) applied diagonally, either above or be low thestrings of the bridge,, an application to the upper str ings being deemed perferable inordinary cases) and is confined to the strings by bolts, spikes ot trenails, or by any or all these modes of fastening combined, the bolts, and c. passingthroug the bract timbers at their intersections, and through *mA or into the strings at the places where the former are attached to the latter. and c.  and c." " The improvements described in the foregoing specification, and claimed as new and useful consist in the application and use of Lattice work in the manner and of the description herein explained, for the purpose of imparting the requisite lateral stiffness to wooden bridges, in a manner more simple,, economical and efficient, than the means heretofore employed for that purpose; it being understood that Lateral and horizontal stiffness, in contradistinction to vertical and transverse inflexibility, is the object of this in-tion"
Patent ofl837 1st. The applicaton and use of arch braces in connec-
ton with the truss frames of mm?	my bridges, in aman-
ner and form different from those heretofore injjse.

" 2
s
2nd. The adoption mi ..... " M  rn rrj iniii	of cast; iron step
to receive and countggtbhe thrust of the main braces 3d. A method of enlarging the abutment, and pier posts, as also all the posts directly above the bolster frames, and all ofthe main braces connected therewith, for the purpose of giving more spacious and efficient bearings to receive the increased actiavi to which these parts are liable in sus taining the weight of tfe bridge and its load.
4th.A more simple and economical manner of constructing bridges of short spans. And,
5th. A method of constructing draw bridges,applicable inconnec-tionwith my plans of bridge building heretofore patented, or inconnecton with other plans of bridge'building adopted by othp ers; all of which improvements, especially in their applications bridges built under my former patents, are believed to be new and original; and c and c .
Col Long gives very careful and full directions in regard to the selection of the timber its proper dimensions for spans of various lengths ; itsafitfamragtion and manner of adjustment; he' keyed up the truss so that the loading pro duced greater strains than when the bridge was unloaded; he also advocated making the spans , if there were more than one , continuous; claiming that this results in an increased efficiencyof the structure amounting to double of what it woulfl afford without
jp.-hi.	it admit!ort that 'tihia
But he adds in afoot note " it is admitted that this principle is rendered operative in the lattice bridges invented by Mr. Town, but ti should be borne in mind, that his bridge frames are not truss frames, din as much as they are completely destitute if keys, wedges or trussing fo any kind, and are trenailed, rather than truss frames."
Long asked a royalty of one dollar per foot of bridge for his patents
Long's pamphlet was loaned me by Col. Julius W. Adams;vol. of miscel. reports no 12

[handwritten list of bridges]