COXE ’9 TRAVELS IN RUSSIA. 665

The bridge is conftruCied on the fame principle as that of SchafFhaufen, exceptingthat the mechanifm is more complicated, and the road not fo level. I fhall attempt todefcribe it by fuppofing it finiflied, as that will convey the bell; idea of the plan. Thebridge is roofed at the top, and enclofed at the fides : it is formed by four frames oftimber, two on each fide, compofed of beams or trufies, which fupport the wholefabric. The road is not carried over the top of the arch, but fufpendcd in the middle.

Feet.

Length of the abutment on the north end - - 658

Span of the arch - - . - 980

Length of the abutment on the fouth end - - 658

Length of the whole ftrudture - - 229 6

The plane of the road upon its firft afcent makes an angle of five degreesw ith the ordinary furface of the river

Mean level of the river to the top of the bridge in the center - 168

Ditto to the bottom of the bridge - . . . 126

Height of the bridge in the center - 42

Height from the bottom of the bridge in the center to the road - yHeight from the bottom of the bridge to the water - . 84

Height from the water to the fpring of the arch - - 5b

There is a difference of thirty-five feet between the road at the fpring of the arch,and the road at the center; in other words, an afcent of thirty-five feet in four hun-dred and ninety, which is little more than eight tenths of an inch to a footThebridge is broadeft toward the fides, and diminifhes towards the center.

In the broadefl part it is . - 168 feet.

In the center or narrowed: - ' - 42

The breadth of the road is - . 28

The artift informed me, that to conftruQ: the bridge would require forty-nine thou-fand fix hundred and fifty iron nails, twelve thoufand nine hundred and eight largetrees, five thoufand five hundred beams, and that it would coft 300,000 roubles, or6o,oool. He fpeaks of this bold project with the warmth of genius, and is convincedthat it is practicable. I muff own, I am of the fame opinion, though I hazard it withgreat diffidence. What a noble effedt would be produced by a bridge fpringing acrofsthe Neva, wdth an arch nine hundred and eighty feet wide, and towering one hundredand fixty-eight feet from the furface of the water ! The defcription of fuch a bridgefeems almolt chimerical; and yet, on infpefting the model, we are reconciled to theidea. But whether the execution of this ftudendous work may be deemed poffible ornot, the model itfelf is worthy of attention, and reflefts high honour on the inventivefaculties of untutored genius: it is fo compafl:, that it has fupported three thoufandfive hundred and forty pood, or one hundred and tw'enty-feven thoufand four hundredand forty pounds, without fwerving from its dire&ion, w'hich is far more, in proportionto its fize, than the bridge, if completed, would have occafion to fuftain from the pref-fure of the carriages added to its own weight.

The

* The afcent of the road of the bridge of SchafFhaufen is barely four, tenths of an inch in afoot.

VOL. VI. 4 Q