Lee B. Hotchkiss and Beverly Stern
Objective
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1. Learn the names and locations of the following rivers: Housatonic, Naugatuck, Willow Brook, Mill, Quinnipiac, West and Hammonasset.
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2. Draw in the boundaries of the Willow Brook and Mill River drainage basins.
Materials
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1. overhead transparencies showing the maps in figures 5 and 6
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2. The New Haven and Mount Carmel quadrangle topographic maps.
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3. The
State of Connecticut
relief map and the
Natural
Drainage Basins
in Connecticut map
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4. Worksheet in figure 10
Background
A drainage basin is an area separated from adjacent basins by a divide or ridge. All surface water originating in a basin moves to lower levels and eventually leaves the basin at the lowest point in the divide through which the main river flows.
Procedure
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1. Using a transparency of figure 5 on the overhead projector, review the major water basins in Connecticut, the four large sub-basins of basin 5, and where in sub-basin 53 the Willow Brook and Mill River basins are located.
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2. Hand out worksheets of figure 10.
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3. Have students write the definition of a water basin on the back of worksheet.
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4. Have students write in the names of rivers using a transparency of the worksheet to give them the names.
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5. Working in pairs, each with his or her own worksheet, have them determine where they think the boundaries of these two basins would be by studying the New Haven and Mount Carmel quadrant topographic maps.
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6. When completed, put up the
State of Connecticut
relief map and the
Natural Drainage Basins in Connecticut
map and carefully look at the two basins on each map. Each student should correct any errors that may be on his or her worksheet.
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7. Study names and locations of rivers and the basin boundaries for homework.
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8. Test: given new worksheet, fill in names of rivers and sketch boundaries of the two basins from memory.
Figure 3—Political Boundaries
(figure available in print form)
Figure 4—Major Rivers in Connecticut
(figure available in print form)
Figure 5—Major Drainage Basins in Connecticut
(figure available in print form)
Figure 6
(figure available in print form)
Figure 7—Altitude of river where arrow is pointing is 140 feet
(figure available in print form)
Figure8
(figure available in print form)
Figure 9
(figure available in print form)
Figure 10—Long Island Sound
(figure available in print form)
Water Power
In the hydrologic cycle, as water evaporates from various surfaces it increases the amount of vapor in the air. As the air and vapor circulate, some of the vapor rises, cools and forms particles of water large enough to fall to earth. When the water falls on ground higher than sea level, the water collects and begins to flow down from the higher level to sea level.
It is the force created by the flowing and falling water as it moves to sea level that forms the basis of all water power
. How part of this force has been harnessed and changed into mechanical power for our use is what this section is about.
Historically there are three levels of water power development. The first level harnessed power to run mills for local needs like grinding flour or sawing logs. The second level of development took place during the first half of the nineteenth century when there was a transition from the water mills which served local needs to those whose primary goal was the commercial conversion of raw material for the general market.
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New England textile mills exemplified this type of development. The third level evolved with the development of hydroelectric power plants.
The grist mill is representative of the first level. I want to go into some detail on the development of the grist mill because of its interesting technological development and because the other two levels naturally followed from it.
A grist mill grinds grain into flour. Grinding grains such as wheat, barley or oats, makes them easier to digest. People have been grinding grain since ancient times. The earliest people used stones for rubbing grain (figure 11). The Egyptians used a saddlestone (figure 12). The early Greeks used a mill with a handle that swiveled and stones with carved surfaces (figure 13). Later they used a mill made of two round stones, a bottom stationary stone called the bedstone and a top rotating stone called the runner. Grain was poured into the hole at center of the runner stone and as a person turned the handle the grain would be rubbed and ground between the two stones. The millstones were carved to provide a sharp cutting surface and to lead the grain from the center of the mill to the outer edge where it would spill out as flour (figure 14).
Figure 11—(Illustration sketched from
The Mill
p.34)
(figure available in print form)
Figure 12—(Illustration sketched from
The Mill
p.34)
(figure available in print form)
Figure 13—(Illustration sketched from
The Mill
p.34)
(figure available in print form)
Figure 14—(Illustration sketched from
The Mill
p.34)
(figure available in print form)
The development from rubbing stones to such a hand grist mill took thousands of years. Using a grist mill was certainly easier than doing it by rubbing stones, but even this required a great deal of time to provide the flour needed by a community.
The Greeks and Romans both used water power to run grist mills, but they were slow to develop its use. Possibly this might have been because they had slaves. The Greeks had a horizontal water wheel which was on an upright, vertical shaft. As the river turned the wheel, the shaft turned and this turned the upper stone of a small millstone above.
The Romans had a vertical water wheel which was basically boards on a shaft. As the river pushed against the boards, it turned the wheel, which turned the shaft. The shaft was connected to gears which transferred the motion to the rotating of a millstone.
The technology of a typical grist mill used in Europe and America in the seventeenth and eighteenth centuries is illustrated in figure 15. The water would fall into the buckets, descendants of the ancient wheel boards, and the force and weight of the falling water would weight it down and the wheel would turn.
The shaft or axle of the wheel would rotate as the wheel rotated. The shaft usually went through one wall of the mill to a space below the first floor. Attached to the shaft was a wooden wheel called a crown or pit wheel. The crown wheel had wooden pegs or cogs mounted near its circumference. As the water wheel shaft turned so did the crown wheel with its cogs which then meshed with and turned a gear mounted at the end of a vertical shaft. This second gear was called a wallower or latern pinion. The motion of the water wheel turned the crown wheel gear which turned the latern pinion gear that turned the vertical shaft to which it was attached. This shaft, which went up to the floor above and through the center of a pair of millstones, was attached to and turned the top millstone.
This was the basic water powered grist mill. The process was the same as that used in the small, hand-turned grist mill. Two stones were used, the bottom stationary stone was called the bedstone and a rotating top stone called the runner. Two major changes, of course, were that the runner stone was now turned by the power transferred to it from the water wheel and the millstones were much larger. In fact they generally were about four feet in diameter, a foot thick, weighed approximately a ton and turned at 120-150 revolutions per minute. If you visit the site of the Whitney Armory in Hamden, you can see two old millstones that were excavated there. If you do stop to see them, look for carved marks on their surfaces.
Figure 15
(figure available in print form)
Milling took skill. Just as with the hand mill the groves on the surface of each millstone had to be correctly carved to provide a sharp cutting surface and lead the grain from the center to the edge. The distance between the stones and the speed of rotation had to be right or the flour could become lifeless or burned. Carelessness could even cause sparks and start a fire. Mill fires were not uncommon.
This type of mill, one that did a single repetitive task and whose equipment was quite directly connected to the water wheel gradually gave way to larger mills or factories. The larger mills had many machines. As all the machines could not be run directly from the water wheel shaft, systems of gears, shafts, pulleys and belts were derived. These systems were called powertrains and they transferred the power of the moving water wheel to machines that were relatively far from it. A working example of a water power factory is Slater Mill in Pawtucket, RI. You can visit this site, see, hear and feel its great water wheel turn and watch how the power is transferred through a system of gears and shafts to an upstairs powertrain that extends the length of a
long
room. The powertrain is attached to the ceiling. The motion of the water wheel is transferred to the turning of the powertrain’s long shaft from which there are many belts that can be moved in place to cause various machines to begin moving.
The old mills were anchored at the waters edge. The water power was used right there. The larger mills and factories transferred the power from the rivers to where their various machines were located. This is a significant characteristic of the second level of water power development. Both books,
The Mill
and
Mill
, clearly describe and illustrate this development.
The third level of water power evolved with the development of hydroelectric power plants. The early horizontal type water wheel developed through the centuries into a tub wheel and then a turbine.
A turbine is a machine that has a rotor or wheel which is a shaft that has a series of blades, vanes or buckets around it. Water is lead in to strike the blades to make the wheel rotate. The shaft of the wheel, of course, rotates with it.
The rotating shaft extends from the turbine into an electric generator which is basically a spinning magnet within a structure of coiled wire. It is the motion of the water that is transferred to the revolving turbine blades and shaft which then turns the magnet within the electric generator. It is the spinning of the magnet within the coiled wire that produces electricity.
Once electricity is produced it is conducted through wires to wherever it is wanted. The power of the water was changed into the power of electricity and that power travels very far from its water source. The transfer of power from its source to locations further and further away is an important characteristic of water power development.
Why was this significant? It meant factories did not have to stay near the water power site. They could move and cause significant changes in the locations they moved from and to. The advancing technology saw new jobs created, old ones abandoned and legal issues over water rights developed. The availability of relatively abundant and inexpensive power has effected every aspect of our lives.
Some Related Math Activities
There are many ways the math inherent in this area could be used. Working with gears and river velocity and flow are described below.
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1. Students can sketch the design of the technology of an early grist mill. Problems on gear ratios and the changing of speeds and direction could be part of this. Questions could be asked such as, “How can a water wheel turning 7 revolutions per minute turn a millstone that revolves at between 120 and 150 revolutions per minute?
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2. A field trip to the Mill River just west of the Orange Street bridge in East Rock Park would be a good place to measure the velocity and flow of a river.
To find the velocity place markers at certain distances in the river. Go parallel to its sides. Time how long it takes a floating object to cover that distance. You’ll get X number of meters or feet per Y number of seconds. Keep it as a general rate or change it into a unitary rate. Discuss both the changing and if one form is more meaningful to them than the other.
To find the flow, pick a point in the river. Determine the shape of the river and the dimensions. You will need to determine the area of the river at that point as if a plane had passed through it. See shaded area A in figure 17.
Next determine the distance the river goes in one second. That is d in figure 17. Multiply the area times the distance and get the number of cubic feet (or meters) of water that pass that point in one second. That is the river’s flow, cubic feet per second or cubic meters per second.
Trying to determine velocity and flow would certainly illustrate the difficulty of getting exact measurements. Estimating and amount of error would naturally come up.
Figure 16
(figure available in print form)