Chap. VIII.

BRITAIN.

455

the landings, not less than 18 inches each stone. The piers are then to commence, and tobe 4 feet wide at the bottom, and set off 1 until at 4 feet high, they are to be reduced to 2feet 3 inches wide. The cross walls, where necessary, are to be done in the same manner.The retaining walls above and below the springing of the arches are to be 2 feet 3 inchesthick, and to batter, as shown in the drawings, at the springing of the arches; over eachpier there is to be a complete course of Bratnley Fall, Painshaw, or Derbyshire stone, 18inches thick, well-dressed and bedded in mortar, hereafter to be described.

« The arches are all to be semicircular, 16 feet span each, and 18 inches deep at the crown,and increasing in the haunches, as shown in the drawings. The brickwork is to be com-posed of the best hard well-burnt grey stock bricks laid Hush in mortar of three parts ofclean sharp river sand to one of the best well-burnt Dorking , Merstham, or other limeequally good, the interior mortar to be composed of four parts of sand to one of lime.

“ The roadway to be formed with 18 inches of sound tough clay, well-beaten and puddledtogether, so as to be impervious to water, 3 inches of sand and 12 inches of flints, brokenequally into small pieces about 2 inches diameter, and mixed with a small portion of chalkat the surface, and well-dressed and rolled together; the clay, sand, and flint are to be laidinclining towards the gutters.

“ On each side of the road is to be a foot pavement 9 feet wide, to be composed of thebest Yorkshire landings, 4 inches thick, and laid in courses not less than 2 feet 3 incheswide, and no stone to contain less than 4 superficial feet; they are to be fair-tooled on theirupper beds, and squared in their lower beds; the joints are to be properly dressed and setin mortar, before described; at their side they are to be bordered by curbstones of the bestgranite, as before mentioned, not less than 12 inches wide, and 9 inches thick, and 4 feetlong, to break bond well with tl»e landings, and to be properly fitted to them, the whole ofthe paving to be laid in the best manner. There is to be a paved gutter on each side of theroad, to be done with the best granite pitching paving, as before, not less than 4 feet wideand 9 inches deep, done in the best manner.

“ Mortar _The mortar of the different parts of the bridge is to be composed of two kinds,

namely, lime inortar and pozzolano mortar; the former is to be composed of the very bestDorking , Merstham, or other lime equally good, well-burnt and ground up in a mortarmill on the spot to a fine powder in its dry state, and afterwards mixed with the requisiteproportions of clean sharp river sand and water under the mortar mill. The lime mortarfor the whole exterior of the bridge and arches, with the exception hereafter to be mentioned,is to be composed of three parts of sand and one part of lime; the exterior must be understoodto extend 3 feet inwards ; the interior mortar to be composed of four parts of sand to onepart of lime, except where otherwise mentioned. The exterior mortar for the piers andabutments, from the foundations up to the Trinity House high water mark of spring-tides,is to be composed of one part of the best pozzolano, one part Dorking or Merstham lime,and two parts of sand, to be well-mixed and ground up together under the mortar mill, asbefore described.

« The whole of the workmanship and materials above described to be of the best descrip-tion of the respective kinds, and to be executed to the entire satisfaction of the principalengineer appointed to direct and superintend the works, who shall have full power duringthe progress of the work to reject all improper workmanship and materials, or to makesuch alterations or additions in the plans and specifications alluded to, as the nature of thefoundations or the circumstances may, in his opinion, require; proper allowances beingmade to the contractor where additions are made, or deductions where diminished, accordingto the scale of prices to be delivered in and approved of at the time of making the contract;and if any difference should arise between the engineer and the contractor as to any matter,clause, or thing in the specification or plans above alluded to, the same to be decided by theprincipal engineer, without reference to any other party or parties whatsoever.”

The contract contained the following covenants on the part of the contractors : —

“ To execute and perform in a substantial, perfect, and workmanlike manner, and to thesatisfaction, and according to the directions, of the principal engineer for the time being,without reference to any other person or persons, all the cofferdams, excavations,foundations, abutments, piers, centres, arches, spandrils, buttresses, stairs, walls, cornices,parapets, embankments, and other works of every description, which shall be required tobe done and executed in and about the building, executing, constructing, finishing, andcompleting the new bridge, and the approaches thereto, and the road and footway over thesame, according to the plans, and under and subject to the directions, rules, regulations, andexplanations and restrictions mentioned or referred to in the above specification, with suchalterations, if any, as may from time to time be directed by the principal engineer in mannerhereinafter mentioned.

“ To find and provide all the stone, timber, iron, bricks, mortar, lime, sand, chalk, gravel,clay, and other materials necessary for executing the works of the kinds and descriptionsmentioned in the specification, to be directed by the principal engineer, or the resident

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