O’Neil laughed with the others at this display of sectional pride, and then explained:  “The problem of passing them sounds difficult, but in reality it isn’t.  If those other engineers had looked over the ground as I did, instead of relying entirely upon hearsay, we wouldn’t be meeting here to-day.  Of course I realized that we couldn’t build a road over a moving river of ice, nor in front of one, for that matter, but I discovered that Nature had made us one concession.  She placed her glaciers on opposite sides of the valley, to be sure, but she placed the one that comes in from the east bank slightly higher upstream than the one that comes in from the west.  They don’t really face each other, although from the sea they appear to do so.  You see the answer?” His hearers nodded vigorously.  “If we cross the river, low down, by a trestle, and run up the east bank past Jackson glacier until we are stopped by Garfield—­the upper one—­then throw a bridge directly across, and back to the side we started from, we miss them both and have the river always between them and us.  Above the upper crossing there will be a lot of heavy rock work to do, but nothing unusual, and, once through the gorge, we come out into the valley, where the other roads run in from Cortez.  They cross three divides, while we run through on a one-per-cent grade.  That will give us a downhill pull on all heavy freight.”  “Sounds as simple as a pair of suspenders, doesn’t it?” inquired Slater.  “But wait till you see it.  The gorge below Niagara is stagnant water compared with the cataract above those glaciers.  It takes two looks to see the top of the mountains.  And those glaciers themselves—­Well!  Language just gums up and sticks when it comes to describing them.”

Mellen, the bridge-builder, spoke for the first time, and the others listened.

“As I understand it we will cross the river between the glaciers and immediately below the upper one.”

“Exactly!”

He shook his head.  “We can’t build piers to withstand those heavy bergs which you tell me are always breaking off.”

“I’ll explain how we can,” said O’Neil.  “You’ve hit the bull’s-eye—­the tender spot in the whole enterprise.  While the river is narrow and rapid in front of Jackson—­the lower glacier—­opposite Garfield there is a kind of lake, formed, I suppose, when the glacier receded from its original position.  Now then, here lies the joker, the secret of the whole proposition.  This lake is deep, but there is a shallow bar across its outlet which serves to hold back all but the small bergs.  This gives us a chance to cross in safety.  At first I was puzzled to discover why only the ice from the lower glacier came down-river; then, when I realized the truth, I knew I had the key to Alaska in my hands.  We’ll cross just below this bar.  Understand?  Of course it all depends upon Parker’s verdict, but I’m so sure his will agree with mine that I’ve made my preparations, bought Omar and gathered you fellows together.  We’re going to spring the biggest coup in railroad history.”