The digging into the rock was done with big chisels—what a carpenter would call "round-nosed" chisels. These chisels, of course, were made of ice. They were what are called the "tongues" or "lobes" of glaciers. As a glacier flows along—always on some down grade—there are portions of it—those long lobes or tongues—that move on ahead of the main mass. This is because those parts of the ice sheet strike a steeper bit of land than the rest of it, so how could they help moving faster?
THE THOUSAND-YEAR CLOCK AT NIAGARA
You've heard of eight-day clocks and clocks that have to be wound only once a year, but here is a clock that was wound up several thousand years ago and is still going beautifully! In placing the wondrous waterfall in Niagara River the glaciers also started a kind of water-clock by which to record—for those who would take the trouble to study it out—how long ago it was the glaciers visited us. Owing to the constant wearing away of the base of the falls, by the water grinding the pebbles against it, great blocks like the one here shown (known as "The Rock of Ages") come tumbling down. So the falls are constantly retreating up-stream, and the distance from where they once stood to where they are now gives a rough idea of the time that has passed since the Old Men of the Mountain set them up in business—about 25,000 years.
The fronts of these lobes are rounded like the waves flowing up a beach, or syrup travelling over pancakes on a cold winter morning. The reason of this roundness is that the centres of these lobes of ice or water travel fastest because the mass on either side furnishes a kind of ball-bearing for the central part.
But this wasn't all. At the very same time, by the very same act, Labrador, Keewatin & Co. set Niagara Falls up in business. In those days there was a Niagara river but no Niagara Falls; at least not the one we know to-day. The ice filled the Ontario Valley so that the streams flowing into it had to turn around and flow south. The Niagara River was one of these streams. Then, as the ice melted, it poured loads of extra water into Lake Erie, so that it was some 30 feet higher than it is at present and began draining out through the new Niagara River, over the rocks that make the falls.
A BIRD'S-EYE VIEW OF NIAGARA
This is a bird's-eye view of the Niagara region. Where the river crosses a bed of limestone below Buffalo, and again where it crosses another just above the crest of the falls, some of the rock has been dissolved away, thus making it rougher, so that slight rapids have formed. Then comes the mighty plunge, after which the water flows through a gorge for about seven miles. Where the gorge bends abruptly at right angles is the great eddy called "The Whirlpool."
NATURE IS THE ART OF GOD