Australia Lesson Activities - Science

Tiger Creek to Lake Emma
67 km

The x360 team pulled out of our rainforest camp a bit later than we wanted, about 8:45am. The road surface was hard-packed red soil for the first hour or so, until we turned up the Battle Camp Road towards the Normanby River. Crister, who was leading the team for the day with the topographical maps and GPS, let us know that the next ten kms to the river would lead us through a small range of mountains. No worries, hills aren’t bad, we thought. But the road surface was.

At the base of the first hill the road surface changed to loose sand and soil. There were a number of Land Cruisers, Land Rovers and other outback-equipped vehicles using the track, and we entered a 40km stretch of alternating sand, a bit of good packed surface, and the cyclist’s lament, corrugation/washboard/bump-after-bump from here to forever.

Those of you who live where there are dirt roads on loose soil know what we rode on today. We couldn’t go fast, like the vehicles, and ride along the top of the ridges. If you go too slowly your rear end and spine take quite a beating. Out mountain bikes took quite a beating, as did our wrists, necks and legs.

So, why do roads develop bumpy, or corrugated surfaces, like road waves, where the same type of bump appears over and over? We don’t know exactly, but here are some thoughts. How about waves on the sea: they’re caused by repeated wind action. How about sand on the bottom of the sea, where currents make ripples on the sand bottom. Cirrus clouds before a storm form waves in the sky. And when car tires move along a road the repeated pattern of ‘road waves’ is formed.

But again, why? We think it is related to a branch of mathematics and science called “Chaos Theory,” where random events form a pattern through repetition. Each tire hits a small bump. The tire is spinning; it has energy transferred from the drive shaft. It bounces up a bit, over the bump and lands, spinning, throwing some sand backwards. It hits the next bump, over, hits, spins and throws more sand backwards. Each time a car comes by, the bumps get a little bigger, more are formed, and eventually there are miles of evenly spaced bumps to bedevil cyclists like us.

An observation: most corrugation is on uphills. Most, but not all. Today we had washboards appear on dead-flat stretches of road. So, a question: to what extent is the creation of corrugation dependent on road surface?

So, somewhere on a completely flat surface (a newly-graded road, calm sea, etc.) there had to appear the first bump, the first wave. How? Why? It is chaotic, a pattern appearing out of randomness.

If you’re interested, check out this website for further amazing thoughts on corrugation/patterns/washboard and Chaos: search for “Treebeard’s Stumpers” a great list of Science related questions and other oddities from Mark Kummel, a Science teacher and naturalist from California.

So, we’re all a little sore from the beatings we endured today on the corrugated Battle Camp Road, but we had time to observe our surroundings and think about Chaos Theory. What a fine day it was!

The process of extracting gold from the Palmer River gold fields of the 1870s was no easy task. As much as twelve tons of machinery was needed to extract the ore from the rocks in each location.

Sites selected for the machinery were on the reefs where the greatest amount of work was being done. Miners’ accounts recall, “The two principal mines are the Ida and the Queen of the North. They are by the employment of labor quite capable to give full employment to two machines now in transit.”

The road from Cooktown to Maytown was 150 miles of the roughest country in the north. Often, machinery had to be dismantled to be lowered and raised by block and tackle over the rough terrain. It cost more than 800 pounds to bring the first ore crushing machinery from Cooktown to the Palmer.

Depths in mines could reach 120 feet to extract the ore. The greatest average thickness was about two feet carrying gold throughout. The best blocks of stone were obtained from the deepest levels.

The arrival of Messrs Edwards and Co’s machine caused great excitement among the miners. It was a ten stamper, six hundred weight, driven by a twelve horsepower engine and capable of averaging ninety tons a week. It was installed on the banks of the Palmer River. Crushing batteries were erected on the bank of a river whenever possible, as a good supply of water was essential for the crushing of ore. Huge bed logs were needed for the battery and the steam engine that drove it. Trees were felled, then floated down river, guided by strong swimmers to keep them clear of debris.

As the Wet season approached, the lack of feed for teams used to cart the ore to the stampers became a problem. Animals died due to starvation. The machines were ready to begin crushing in December. There were more than sixteen hundred tons of ore waiting to be treated.

Despite the hardships, enthusiasm ran rampant. Around Maytown, rich quartz specimens were being shown around. Early results had fulfilled expectations. From the Queen of the North, 110 tons of quartz had returned 915 ounces of smelted gold, a little over eight ounces ore per ton. The Maytown reefs were about to come into their own!

Suggested activities: Research mining techniques, past and present, in your area. Determine how machinery plays a role in the extraction of the ore in the mining process.