In a more relaxed frame of mind, he encouraged Silas to take the lead. Suddenly, Silas came upon a huge rock just off the sandy trail and said excitedly, "Look at the glacial striations. This boulder must’ve been under the glacier at one time!"
"You’ve got sharp eyes," said Peter, while Toby and Jeremy crowded around the big rock to see what the excitement was about.
"He’s also looking around him with not just his eyes but his mind as well," said their father. "Ideas help us to see what we might otherwise fail to notice. If Silas had just noticed the grooves on this rock it might not have made any impression. But knowing the significance of such markings he could infer that this boulder was carried here by the glacier from higher on The Mountain and dumped when the ice melted as climate changed. The boulder’s location so far from the present ice tells us how much bigger the glacier used to be."
"I guess you can say knowledge can sharpen our eyesight," suggested Mrs. Cameron. "What is the word geologists use for a glacial boulder like this? I used to know it."
"A ‘glacial erratic’."
"A rattic--that’s a funny word," said Peter.
"There’s a reason for that name," said his father. "When geologists in Europe first began to wonder about such boulders, they noticed they were often a different kind of rock than made up the bedrock on which they rested. They seemed abnormal, or out of place, hence ‘erratic’--in error. When geologists figured out that glaciers had transported such boulders considerable distances from their places of origin, they realized why they were indeed ‘out of place’."
Soon the Camerons were treading on a needle-covered path in a deep forest. They followed the glacier’s runoff a long way down until the trail veered off to an uphill climb out of the valley floor. Emerging into a clearing they were taken unaware as a full view of The Mountain suddenly burst upon them. Its immensity filled the scene. Winthrop Glacier’s stupendous mass, three and a half square miles and five-mile length, spread from the top of The Mountain all the way down to below where they stood. Several moraines, consisting of rocks originally scattered through the glacier and now forming ridges of glacial till, defined its broad terminus.
This amazing evidence of previous glacial advances thrilled Professor Cameron, but at the same time he worried about the river of glacial meltwater his family would soon have to cross. They hiked down the treacherous lateral moraine, left by the glacier’s shrinkage, through a chaotic jumble of shifty stones, to the extensive area of terminal moraines they had seen from above.
The Mountain’s sheer bulk amazed the Camerons. Magnified by Winthrop Glacier and rocky moraines left by a history of glacial advance and retreat, its hugeness overwhelmed them. They stood silently and marveled at the glacier and its mountain host. The power here represented, and the volume of material that could be suddenly unleashed, filled their minds with respect and admiration.
Mrs. Cameron at last found words: "I’ve never felt so small and insignificant," she said as they continued to gaze in speechless wonderment.
"I’ve never felt so powerless against the forces of nature," agreed Professor Cameron. He sounded somewhat apprehensive.
They stood transfixed. Silas finally broke the spell by asking, "How many glaciers are there on Mount Rainier?"