The Scientific American Boy; Or, The Camp at Willow Clump Island
Chapter 48
THE WINDMILL.
When our log cabin was completed we immediately transferred our camp from the tent to the hut. But at the very outset we were confronted with the problem of getting drinking water. We hadn't thought of that before. It was easy enough to move the filter barrels, but when it came to moving the water wheel we could find no suitable place for it anywhere near the log cabin. The water of Lake Placid was too quiet, while the mill-race and the rapids on the other side of Kite Island ran so swiftly that we were afraid the water wheel would be swept away with its course. The matter was carefully considered at a special meeting of the society. It occurred to Bill that we might build a windmill in place of the water wheel, and use it to pump water from a well which could be dug near the hut.
"We wouldn't have to use a filter, then," he said.
"Why not?" I asked.
"Why, because the sand of the island will strain out all the dirt in the water. You see, the water in the well will have to soak in from the river, and by the time it gets through all the gravel and sand between the river and the well it ought to be filtered pretty clear."
DIGGING THE WELL.
That sounded logical, and so we adopted the plan at once. We chose a spot quite near the hut for our well. When we had dug down about 6 feet we struck water, but continued excavating until the water lay 3 feet deep in the well. While making the excavation we shored up the sides with planks, to prevent the loose soil from falling in on us and smothering us, as it so nearly did when we were digging our first cave. By "shoring," I mean we lined the walls with planks, which were driven into the ground with large wooden mallets. The planks were braced apart with sticks at frequent intervals. As the well hole grew deeper we had to rig up a bucket to haul the dirt out. Our bucket was a soap box attached to a rope, which passed through a pulley at the top of the well. The pulley was supported by a tripod made by firmly lashing together the upper ends of three stout poles and spreading their lower ends far enough apart to straddle the mouth of the well, as shown in Fig. 282. After the well had been carried down to a sufficient depth, we began laying the stone wall, which was to form the permanent lining. We knew that the wooden walls would not do, because they would soon decay. Our stone wall, which was built up of flat stones like the chimney of the log house, was not very strong, I fear, and had not the soil around it been pretty firm it would probably have caved in. However, if it served no other purpose, it formed a fairly good finish for the well.
THE WINDMILL TOWER.
The mouth of the well was carefully covered with planks while we constructed the windmill above it. For the tower of the windmill we chose four long sticks. They must have measured about 16 feet in length, and were from 4 to 6 inches in diameter. With them we made two frames of the form given in Fig. 283, using slabs to brace them apart. These frames were now set in position, with their lower ends firmly planted in holes in the ground, and the tower was completed by nailing on a number of diagonal braces. A couple of boards were nailed across the upper ends at opposite sides, and holes were drilled through them to provide bearings for the wind wheel shaft.
THE CRANK SHAFT.
The shaft was a piece of heavy iron rod which we procured from the blacksmith at Lumberville. Under Bill's direction the blacksmith hammered a U-shaped bend at the center of the shaft, so as to form a crank, and then he flattened the rod near the ends (see Fig. 284). When the shaft was set in its place these flat spots lay just outside of the bearing boards, and then, to keep the shaft from sliding back and forth in its bearings, we fastened on two clamps over these flattened parts. The clamps were made of pairs of hardwood blocks bolted together in the manner indicated in Fig. 285.
THE WIND WHEEL.
Our next task was to construct the wind wheel. First we procured three boards, each 3 inches wide and 3-1/2 feet long. A 1/2-inch hole was drilled in the center of each board, and then, with these holes coinciding, the boards were nailed together, with their ends projecting, like spokes, equally distant from each other. Six wedges were now made of the size indicated in Fig. 286. These were made of a 2 x 4-inch scantling, sawed diagonally in two and then planed down to the given dimensions. The wedges were now nailed firmly to the spokes, as shown in Fig. 286. For the blades we used six thin boards, each about 4 feet long. Each blade measured 10 inches in width at the outer end, and tapered down to a width of 3 inches at the inner end, as illustrated in Fig. 288. The blades were now securely nailed to the wedges, and their outer ends were braced together by means of wires stretched from the forward edge of each blade to the rear edge of the next one ahead. The wheel was then fitted onto the shaft and nailed to one of the clamps. In this way it was practically keyed to the shaft.
We did not make any vane for our windmill. It did not need any. The wind nearly always blew either up or down the river, more often up the river, for the prevailing summer winds in that part of the country are southerly. But, aside from that, east and west winds could not very well reach us on account of the hills on both sides of the river. The wheel was set facing the north, because the strongest winds came from that direction, and as an extra brace against these winds we stretched wires from the projecting end of the shaft to the center of each blade.
A SIMPLE BREAK.
A brisk northerly wind was blowing when we set the wheel in place, and it began to revolve at once, before we could nail it to the clamp. To stop it we nailed a stick of wood to the tower, so that its end projected in the path of the blades and kept the wheel from turning around. This brake was swung up to the dotted position illustrated when we were ready to have the wheel revolve, but it could be thrown down at any time to stop it.
THE PUMP.
Our pump was made of a galvanized leader pipe; that is, a pipe used to carry off rain water from the roof of the house. The pipe was only about 8 feet long, and so we had to piece it out with a long wooden box pipe. A block closed the lower end of this box, and the leader pipe fitted snugly into a hole in the block (Fig. 291). A spout was set into the upper end of the box pipe to carry the water to the cask, which was to serve as our water reservoir.
THE PUMP VALVES.
We plugged the bottom of the leader pipe with a block of wood, in the center of which a large hole was drilled. The hole was covered with a piece of leather nailed at one side, so that it could lift up to let water into the pipe. The piston was made of a disk of wood of slightly smaller diameter than the inside of the pipe, and over it was fastened a piece of leather just large enough to fit snugly against the walls of the pipe. This piston was fastened to a wooden rod long enough to reach from well within the pipe to the wind wheel shaft. A strip of brass was bent over the crank, or U-shaped bend in the shaft, and its ends were fastened to the rod.
ACTION OF THE PUMP.
It was rather a crude pump, but it did all the work we required of it. As the wheel went around the crank shaft would move the piston up and down. Whenever the piston went down, the air in the pipe would press up the edges of the leather disk and squeeze past (see Fig. 295). Then when the piston came up again, the leather disk, being backed by the wooden disk beneath it, was kept flat, so that no air could force its way back into the pipe. This made a partial vacuum in the pipe, and the water from the well rushed up through the valve at the bottom to fill it (see Fig. 296). When next the piston went down the bottom valve closed and more air forced its way past the piston. Then on the next upward stroke more water flowed into the pipe, until, after a number of strokes, all the air was pumped out and the water which took its place began to force its way up past the piston and eventually to flow out of the spout into the cask.
Our old windmill was sold to a farmer near Lumberville when we broke camp that fall. We carted it over and set it up for him. A number of years later I saw it still faithfully at work pumping water for his cattle. The original pump had been worn out and a new one substituted, but otherwise the old windmill remained just as we had first rigged it up.