Identifier: britishmarsconta00robs (find matches)
Title: The British Mars : containing several schemes and inventions, to be practiced by land or sea against the enemies of Great-Britain ; shewing more plainly, the great advantage Britain has over other nations, by being masters at sea ; to which is added, an appendix, containing a scheme for manning the British navy, with less grievance to the subject; and a scheme to employ seamen ; of a copper mine near Hudson's Bay and of discovering the North-West passage, or determine there is no such passage ; with cautions and directions
Year: 1763 (1760s)
Authors: Robson, Joseph
Subjects: Great Britain. Royal Navy Military art and science Naval art and science Fortification
Publisher: London : Printed for the author, and sold by W. Flexney
Contributing Library: University of Pittsburgh Library System
Digitizing Sponsor: Lyrasis Members and Sloan Foundation

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as it may be impofibe to know the Breadthof t!:ie Ditch to a certainty, it will be advifeable tohave in readinc^fs thirty-eight or forty Feet of fparelength of Bridge, to be ufcd if n^cefTary, whichmay be eafily provided, by having a folding Part ofthirty or thircy-five Feet long, faitenfd to the afterAxle-Tree with flrong Hinges, and iis after End,(for the better Convenience t,>f travelling) fupportedby Wheels ten Fee: high, fo that the Men appoint-ed to convey it will have fufficicnt PvOom to hawlunder the Badge, and the Wheels m^y be taken a-way at plealure, as loon as the main Body of theBridge is pufned into the Ditch ; and inftead of theWheels, the outer End of the folding Pare may reflupon the covert Way, and by pulhing forward orhawliiig backward the faid main Body, the Bridgemay be made fuicable in length to the Breadth ofthe Ditch; and for the more convenient movingthe fecond Bridge over it, (which fhould be narrowerthan the firlt) it would be proper to fix firft a fold-
Text Appearing After Image:
(21 ) ing Part at the fore End of this fecond Bridge, ofabout twenty Feet long, to face the Ditch. Suppcfe the Ditch to be one hundred and thirty-Feet wide, or a little more, though few exceedfuch a Brt-adth, and not many are lo wide, firftpufb the Bridge as above deicnbed into the Ditch,till only two or three Feet of the after End remainupon the covert Way, which muft be fixed downwith three or four Iron Stakes, or wel faftned wiihRopes to the remaining Parts of the Pallilades ofthe covert Way *: This Bridge v^ill advance fixtyor fixty-two Feet into the Ditrh, and leave fixty-eight or feventy Feet of the Breadth of it, for rhefecond Bridge to btr pufhed along the firfl alreadyin the Ditch. The main Body of the fecond Bridge, like thatof the firft, is underftood to be thirty Feet lorg,with folding Parts at the Ends, each twenty orthirty Feet long, that at the after End to be fup- <ported by two Wheels, and ih^- fore Part to be ele-vated to an Angle of about forty five Degrees, andk

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