125

THE PRINCIPLES OP BRIDGES.

TRACT 5.

part, by building strong abutments of masonry, running 150feet into the river on each side, against which to abut theproposed arch of cast iron, which consequently was to be of600 feet span, extending across the river at one stretch. Theheight of the arch at the crown or key piece, was to be 65feet above high-water, to allow ships of considerable burden,with their top masts only struck, to sail through beneath it,up to Blackfriars bridge; to load or unload by the side ofnew wharfs, to be built into the river, on both sides of it,all the way up to Blackfriars. The width of the bridge, tobe 45 feet in the middle, and from thence widening all theway, in a curved form, till it should become enlarged to 90feet at the extremities.

The letter of the Committee is here given first, with theset of questions, followed by the answers as delivered in con-sequence of that requisition.

TPIE ORDER OF THE COMMITTEE.

“ Luna; 23 die Martii 1801,“ At the Committee for the further improvement of the Portof London ;

“ Charles Abbot, Esq. in the Chair :

“ Ordered, That the Print, Drawings, and Estimates oftin Iron Bridge, of a single arch, 600 feet in the Span,together with the annexed Queries, be sent to Dr. Hutton,requesting that he will, on or before the 25th of April next,transmit to Mr. Samuel Gunnell, the Cfcrk to this Committee,his opinion upon all of these queries, or such of them as hemay be disposed to consider.

“ Charles Abbot, Chairman*

“ To Dr. Hutton ,

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