Striding along the narrow runway of ice-glazed planks with the assurance of goats, the three at last passed under the main traveller, a huge structure of eleven hundred tons' weight that straddled the bridge's sides and rose higher than the towers. Its electromagnetic cranes were folded together and cemented in place by the ice.
A few yards beyond they came to the end of the extension arm of the cantilever and out upon the uncompleted first section of the central, or suspension, span. It was poised high in space, far out over the dizzy abyss. Many yards away, across a yawning gap, the completed north third of the suspension span reached out, above the gulf, from the tip of the north cantilever, like the arm of a Titan straining to clasp hands with his brother of the south shore.
Yet the mid-air companionship of this outreaching skeleton-arm served only to heighten the giddiness and seeming instability of the south-side overhang. From across the broad gap, the eye followed the curve of the bottom-chords of the north cantilever away down into the abyss toward the far shore of the strait, where the lofty towers upreared upon their massive piers.
From this viewpoint there was no relieving glimpse of the shoreward curving anchor-arm that balanced the outer half of the north cantilever alike in line and weight. There was only the vast upcurve of the top-chords and the stupendous down-curve of the bottom-chords and the line between that stood for the foreshortened sixteen hundred feet of bridge-floor level extending from the north shore to the swaying tip of that unanchored north third of the central span.
Few even among men accustomed to great heights could have stood anywhere upon the outer reach of the overhang without a feeling of nausea and vertigo. Not only did the gigantic structure on the far side of the gap seem continually on the verge of toppling forward into the abyss, but the end of the south cantilever likewise quivered and swayed, and the mad flow of the roaring, ice-covered waters beneath added to the giddiness of height the terrifying illusion that the immense steel skeleton had torn loose from its anchorage to earth and was hurtling up the strait through mid-air, ready to crash down to destruction the instant its winged driving-force failed.
Yet Griffith and Blake followed McGraw out to the extreme end of the icy walk and poised themselves, shoulder to wind, on narrow sleet-glazed steel beams, as unconcerned as sailors on a yardarm. Griffith and McGraw were absorbed in a minute inspection of the bridge's condition and in estimating the time it would take to throw forward the remaining sections of the central, or suspension, span, upon the termination of the irksome spell of extreme frosty weather.
Blake looked, as they looked, at post and diagonal, eyebolt and bottom-chord, and across the gap at the swaying tip of the north cantilever. But his face showed clearly that his thoughts were not the same as their thoughts. His eyes shone like polished steel, and there was a glow in his haggard face that told of an exultance beyond his power of repression.
At last Griffith roused from his absorption. He immediately noticed
Blake's expression, and dryly demanded: "Well?"
"Well your own self!" rejoined Blake, striving to speak in an indifferent tone.
"Something of a bridge, eh?"