FORM IV
WINTER
FOREST TREES
EVERGREENS
Several species of evergreens have already been studied. These should be
reviewed, and representatives of other species examined. Mid-winter is
most suitable for the study of evergreens. The following points should
be considered:
1. Description leading to identification
2. Nature of soil and water conditions
3. Common uses of each species of evergreen
4. Collection of wood specimens and cones.
WOOD SPECIMENS
Specimens should be uniform in size and should show bark on one side and
heart wood as well as the outside, or sap wood. They should be about six
inches long, two inches wide on the side having the bark, and should
gradually come to an edge toward the pith, or centre. When seasoned, one
side and one edge should be polished and then oiled or varnished.
Specimens of the wood of the deciduous trees may also be prepared during
the winter.
FRUITS
During the winter months, some time should be devoted to reading and
discussing articles on general farming and fruit growing. Such articles
may be taken from books, magazines, or newspapers, and may be supplied
partly by the teacher and partly by the pupils. These articles will be
appreciated by the pupils all the more because of their studies of fruit
trees during the season. Such topics as the following may be discussed:
1. Best kind of apples, plums, bush fruits, and strawberries. Reports
from the Dominion and Provincial Departments of Agriculture.
2. Method of raising fruit trees--from seed, grafting, and budding.
3. Demonstrations in pruning. This may be done in early spring by taking
a class to a neighbouring orchard.
4. Methods of planting and cultivation.
5. Packing and storing.
6. Spraying. Much information is to be found in Horticultural Journals
and papers, and in Bulletins to be obtained from the Secretary of
Agriculture for Ontario.
Illustrated articles on gardening and fruit growing should be collected
for school use. Views of fine gardens, parks, and home grounds will be
of interest to the pupils. Simple artistic methods of ornamental
planting with trees, shrubs, vines, and herbaceous perennials can now be
introduced, and some scheme for improving the school grounds outlined.
Catalogues should be obtained soon after New Year's and, after examining
their merits, the best varieties of seed and fruit for the district
should be selected. Horticultural societies, as well as Dominion and
Provincial Departments of Agriculture, commonly give selected lists with
descriptions of the different varieties.
WEEDS AND WEED SEEDS
The training in the observation and identification of weeds and weed
seeds, which was begun in Form III, should be continued in Form IV. For
method see Form III.
PHYSICAL SCIENCE PHASE OF NATURE STUDY
WATER PRESSURE
1. Grasp an empty tin can by the top and push it down into a pail of
water. Note the tendency of the can to rise. The water presses upward.
Its downward pressure is evident.
2. Tie a large stone to a string, hold it at arm's length, shut the
eyes, and lower the stone into water. _Note_ the decrease in weight.
This is also due to upward pressure, which we call buoyancy. The actual
decrease may be found by means of a spring balance.
3. Try Experiment 2, using a piece of iron the same weight as the stone.
Is the decrease in weight as evident? Ships made wholly of iron will
sink. Explain.
4. Put an egg into water; it slowly sinks. Add salt to the water; the
egg floats.
EXERCISES
1. Will the human body sink in water? In which is there less danger of
drowning, lake or sea water?
2. When in bathing, immerse nearly the whole body, then take a full
inspiration. Note the rise of the body.
3. Why does ice float? (See expansion of water by freezing.)
4. Balloons are bags filled with some light gas, generally hydrogen or
hot air. They are pushed up by the buoyancy of the air. The rise of
heated air or water (see Convection) is really due to the same force.
Clouds, feathers, and thistledown are kept in the air more by the action
of winds and small air currents than by buoyancy.
STUDY OF AIR
(Consult _Science of Common Life_, Chaps. VIII, IX, X.)
1. Air takes up space. Put a cork with one hole into the neck of a flask
or bottle. Insert the stem of a funnel and try to pour in water. Try
with two holes in the cork. When we call a bottle "empty" what is in it?
2. Air is all around us. Feel it; wave the hands through it; run through
it; note that the wind is air; inhale the air and watch the chest.
3. Air has weight. This is not easy to demonstrate without an air-pump
and a fairly delicate balance.
Fit a large glass flask with a tightly fitting rubber stopper having a
short glass tube passing through it. To the glass tube attach a short
rubber one and on this put a clamp. Open the clamp and suck out all the
air possible. Close the clamp and weigh the flask. When perfectly
balanced, open the clamp and let the air enter again. Note the increase
in weight.
If an air-pump is available, procure a glass globe provided with a
stop-cock (see Apparatus). Pump some of the air from the globe, then
weigh and, while it is on the balance, admit the air again and note
increase in weight.
Tie a piece of thin sheet rubber over the large end of a thistle tube;
suck the air out of the tube and note how the rubber is pushed in. This
is due to the weight or pressure of the air. Turn the tube in various
positions to show that the pressure comes from all directions. To show
that "suction" is not a force, let a pupil try to suck water out of a
flask when there is only one opening through the stopper. If two holes
are made, the water may be sucked up, that is, _pushed_ up by the weight
of the air.
Fill a pickle jar with water. Place a piece of writing paper on the top
and then, holding the paper with the palm of the hand, invert the jar.
The pressure of the air keeps the water in.
A cubic foot of air weighs nearly 1-1/4 oz. Find the weight of the air
in your school-room.
The atmosphere exerts about fifteen pounds pressure on every square inch
of the surface it rests against. Find the weight supported by the top of
a desk 18 inches by 24 inches. If the surface of the body is eight
square feet, what weight does it have to sustain? Why does this weight
not crush us?
THE BAROMETER
The experiments immediately preceding will have paved the way for a
study of the barometer.
1. Fill a jar with water and invert it, keeping its mouth below the
surface of the water in another vessel. If the pupils can be led to see
that the water is sustained in the jar by the air pressing on the water
in the vessel, they can understand the barometer.
2. Fill a tube about 30 inches long, and 1/4 inch inside diameter with
water, and invert it over water, as with the jar in the previous
experiment.
3. Use the same tube or one similar to that in 2 above, but fill with
mercury and allow the pupils to notice the great weight of the mercury.
Holding the mercury in with your finger, invert the tube over mercury.
This time the fluid falls some distance in the tube as soon as the
finger is removed. A tube of this size requires 1 lb. of mercury.
Lead the pupils to see that the mercury remaining in the tube is
sustained by the air pressure, and that any increase or decrease of the
atmospheric pressure will result in the rise or fall of the mercury
column. Leave the barometer (made as in 3 above) in the room for a few
days and note whether its weight changes. The use of the instrument in
predicting weather changes should be emphasized. Compare your barometer
with the records in the daily papers.
The average height of the barometric column is 30 inches at sea-level.
Explain how you could estimate heights of mountains and balloons with a
barometer.
THE COMMON PUMP
This is a valuable application of air pressure. A glass model will prove
useful, but a model made by pupils will be much more so. (See
_Laboratory Exercises in Physics_ by Newman.)
The water rises in the pump because the sucker lifts the air from the
water inside, allowing the air outside to push the water up. A common
pump will not lift water more than about 30 feet. Why is this? Compare
the pump to a barometer. (See _The Ontario High School Physics_.)
EXPANSIVE FORCE OF AIR
Air and all other gases manifest a pressure in all directions not due to
their weight. The power of air to keep tires and footballs inflated and
that of steam in driving an engine are examples. It is this force that
prevents the pressure of air from crushing in, since there are many air
spaces distributed throughout the body.
COMPOSITION OF AIR
This subject and the three immediately following it have a special
bearing on hygiene.
1. Invert a sealing-jar over a lighted candle. Has the candle used up
_all_ the air when it goes out?
2. Place a very short candle on a thin piece of cork afloat on water in
a plate; light the candle, and again invert the jar over it. Note that
the candle goes out and the water rises only a short distance in the
jar; therefore _all_ the air has not been used up.
3. Slip the glass top of the jar under the open end and set the jar
mouth upward on the table without allowing any water to escape. Now
plunge a lighted splinter into the jar. The flame is extinguished.
Air, therefore, contains an active part that helps the candle to burn
and an inactive part that extinguishes flame. The names _oxygen_ and
_nitrogen_ may be given. These gases occur in air in the proportion of
about 1:4. (This method is not above criticism. Its advantage for young
pupils lies in its simplicity.)
OXYGEN
Make two or three jars of oxygen, using potassium chlorate and manganese
dioxide. (See any Chemistry text-book.) Let the pupils examine the
chemicals, learn their names, and know where to obtain them. Perform the
following experiments:
1. A glowing splinter relights and burns very brightly if plunged into
oxygen.
2. A piece of picture wire tipped with sulphur burns with great
brightness.
3. Burn phosphorus or match heads in a spoon. A spoon may be made by
attaching to a wire a bit of crayon having a hollow scooped on its upper
surface. A clay pipe bowl attached to a wire will answer.
From these experiments pupils will learn the value of nitrogen as a
diluent of the oxygen. Pure oxygen entering the lungs would be just as
destructive as it would be entering the furnace.
CARBON DIOXIDE
1. Make a jar of this gas. Washing soda and vinegar will answer if
hydrochloric acid and marble are not obtainable. (Consult the _Science
of Common Life_, Chap. XIII, and any Chemistry text-book.)
2. Lower a lighted candle first into a jar of air then into the jar of
carbon dioxide.
3. Make some lime-water by stirring slaked lime with water and allowing
the mixture to settle. Shake up some clear lime-water with a jar of the
gas. Pupils will be made to understand that the milky colour will in
future be considered the test for carbon dioxide.
4. Have one of the pupils cause his breath to bubble through some clear
lime-water for a minute. Using a bicycle pump, cause some fresh air to
bubble through lime-water.
5. Hold a clear jar inverted over the candle flame for a few seconds,
then test with lime-water.
6. Invert a large jar over a leafy plant for a day. Keep in the dark and
test the jar with lime-water.
Is this gas likely to be in the air? Set a plate of lime-water in the
school-room for a day or two, and then examine it. Try to pour the gas
from jar to jar and use a candle as a test. Is the gas heavier than air?
On account of its weight, the gas often collects in the bottoms of old
wells, mines, and tunnels. It is dangerous there since it will not
support life.
USES:
1. Add a little water to some baking powder and cause the gas that forms
to pass through lime-water. What causes the biscuits to "rise"?
2. Mix flour and water in a jar, add a bit of yeast cake and a little
sugar, and let stand in a warm place. Test the gas that forms, for
carbon dioxide. What causes bread to rise?
3. Uncork a bottle of ginger ale, shake the bottle, and lead the gas
that comes off through lime-water.
4. Most portable fire extinguishers depend on the generation of carbon
dioxide.
Show the similarity between our bodies and the candle. The candle needs
oxygen; it produces heat, and yields water and carbon dioxide. Much of
our food is somewhat similar in composition to the wax of a candle; we
breathe oxygen, our bodies are warmed by a real burning within, and we
exhale water and carbon dioxide.
After exercise why do we feel more hungry? Why do we breathe faster? Why
do we feel warmer? Why does the fire burn better when the damper is
opened?
IMPURITIES OF AIR
All air contains carbon dioxide. If the amount exceeds 6 parts in
10,000, it becomes an impurity, not so much on its own account as
because it indicates a poisoned state of the air in a room, since
organic poisons always accompany it when it is emitted from the lungs.
Other impurities of the air, dependent on the locality and the season,
are smoke, dust, disease germs, sewer gas, coal-gas, pollen dust.
SOLUTIONS OF SOLIDS
(Consult the _Science of Common Life_, Chap. VII.)
Have the pupils weigh out equal quantities of sugar, salt, soda, alum,
blue-vitriol. Shake up with equal quantities of water to compare
solubilities. Repeat, using hot water. Is it possible to recover the
substance dissolved? Set out solutions on the table to evaporate, or
evaporate them rapidly over a stove or spirit-lamp. Try to dissolve
sand, sulphur, charcoal, in water. Obtain crystals of iodine and show
how much better, in some cases, alcohol is as a solvent than is water.
APPLICATIONS:
1. Most of our "essences", "tinctures", and "spirits" are alcoholic
solutions.
2. Digestion is the effort of the body to dissolve food.
3. The food in the soil enters the plant only after solution.
4. The solvent power of water makes it so valuable for washing.
5. Maple sap is water containing sugar in solution.
6. In the salt region along Lake Huron, holes are drilled to the salt
beds, water is poured in, then pumped out and evaporated. Explain.
7. Meat broth is a solution of certain materials in the meat.
8. How could you manufacture salt from sea water?
SOLUTION OF LIQUIDS
Try to mix oil and water, benzine and water, oil and benzine. Only in
the third case do we find a permanent mixture, or solution. Try to
dissolve vinegar, glycerine, alcohol, mercury, with water.
APPLICATIONS:
1. Paint is mixed with oil so that the rain will not wash it off so
easily.
2. Water will not wash grease stains. Benzine is necessary.
3. Why is it necessary to "shake" the bottle before taking medicine?
SOLUTION OF GASES
Study air dissolved in water, by gently heating water in a test-tube and
observing the bubbles of air that gather on the inner surface of the
test-tube. Aquatic animals, such as fish, clams, crayfish, crabs,
subsist on this dissolved air.
LIMESTONE
Pieces of this rock may be found in all localities. Teach pupils to
recognize it by its gray colour, its effervescence with acid, and the
fossils and strata that show in most cases. If exposed limestone rocks
are near, visit them with the pupils and note the layers, fossils, and
evidences of sea action. Compare lime with limestone as to touch,
colour, and action on water and litmus. Try to make lime by putting a
lump of limestone in the coals for some time; add water to this. Other
forms of limestone are marble, chalk, egg-shells, clam-shells, scales in
tea-kettles.
Geographically, the study of limestone is of great importance. Grind
some limestone very fine, add a very little of this to water, and
bubble carbon dioxide through for some time; note the disappearance of
the limestone. This explains how limestone rocks are being slowly worn
away and why the water of rivers, springs, and wells is so often "hard".
Catch some rain-water in the open and test it for hardness. It will be
found "soft". Place a few limestone pebbles in a tumbler with this soft
water and after a day or two test again. The water will be "hard".
Compare, as to hardness, the water from a concrete cistern with that
from a wooden one.
CARBON
Procure specimens of hard and soft coal, coke, charcoal, graphite, peat,
and petroleum. Note the distinctive characteristics of each. Discuss the
uses. Try to set each on fire. Note which burns with a flame when laid
on the coals or placed over the spirit-lamp. Put a bit of soft coal into
a small test-tube; heat and light the gas that is produced. This gas,
when purified, is one kind of illuminating gas. Note the _coke_ left in
the test-tube.
Fill the bowl of a clay pipe with soft coal and seal it up with plaster
of paris. After this has hardened, place the bowl in hot coals or in the
flame of a spirit-lamp and light the coal-gas at the end of the stem.
After all the gas has been driven off, look for the coke inside.
Heat a bit of wood in a small test-tube and light the gas that is
evolved. Note the charcoal left.
Cover a piece of wood with sand or earth; heat, and note that charcoal
is formed. This illustrates the old method of charcoal-burning. This
subject is closely related to industrial geography.
HYDROGEN
A convenient way to prepare hydrogen is to use zinc and hydrochloric
acid with a test-tube for a generator. (Consult any Chemistry
text-book.) Make the gas and burn it at the end of a tube, holding a
dry, cold tumbler inverted over the flame. Note that water is formed.
Conclude what water consists of, namely, oxygen and hydrogen. Water may
be decomposed into oxygen and hydrogen, hence a use of hydrogen may be
shown by attaching a clay pipe to the generator and filling soap bubbles
with the gas. When freed these rise quickly.
MAGNETS
If bar magnets cannot be obtained, use a child's horse-shoe magnet.
Procure small pieces of cork, wood, iron, brass, glass, lead, etc., and
let pupils discover which the magnet attracts.
Have pupils interpose paper, wood, slate, glass, iron, lead, etc., in
sheets between the magnet and the iron and note the effect on the force
exerted.
Note that when one end of a magnet touches or comes near the end of a
nail, the nail becomes a magnet, but not a permanent one.
Magnetize a needle by drawing one of the poles of the magnet from end to
end of the needle, always in the same direction, about twenty times.
Suspend the needle horizontally with a piece of silk thread and note its
position when at rest.
Get a small compass and show how it is related to the foregoing
experiments. Emphasize its use to mariners. If possible, get a piece of
lodestone and show its magnetic properties.
ELECTRICITY
Half fill a tumbler with water and add about a teaspoonful of sulphuric
acid. Set in this a piece of copper and a piece of zinc, but do not let
them touch. Make a coil by winding insulated wire around a block of wood
about ten times. Remove the wood and place a compass in the centre of
the coil. Join the ends of the wire to the two metals in the tumbler.
The sudden movement of the needle will be taken as the indication of a
current.
Let pupils try experiments with many pairs of solids, such as lead and
silver, carbon and glass, wood and iron, tin and zinc, and liquids such
as vinegar and brine.
Show pupils how to make a simple battery. See home-made apparatus, page
50, and consult _Laboratory Exercises_ by Newman. Two or three dry cells
will be found sufficient for any experiments, but the home-made battery
is to be preferred.
Show pupils how to make a magnet by winding a piece of insulated wire
around a nail and joining the ends of the wire to the battery. Make a
horse-shoe magnet by bending the nail and winding the wire about both
ends in opposite directions.
As an application of the electro-magnet, show pupils how to make a
telegraph sounder. (See Manual on _Manual Training_.) If possible,
examine the construction of an electric bell. The motor and electric
light are other common applications of the current. Take up the uses of
the motor in factories, and for running street-cars and automobiles.
Show the necessity for a water-wheel or engine to produce the current,
and for wires to connect. Explain that batteries are not used to produce
large currents, but that machines called dynamos, similar to motors,
when driven by steam or water-power, will yield electric currents as
batteries do.
STEAM
The power of steam may be shown by loosely corking a flask and boiling
the water in it until the cork is driven out, or by stopping the spout
of a boiling tea-kettle, or by letting a stream of steam impinge on a
toy paper wheel. Encourage pupils to learn all they can about steam and
gasolene engines and their uses.
FARM TOOLS
This topic should be dealt with only in so far as it can be made a
subject for actual observation by the pupils. Children should learn to
be thoughtful and observant and to do all kinds of work, manual as well
as mental, intelligently.
MACHINES
(Consult _The Ontario High School Physics_, Chap. IX.)
LEVER.--When a _lever_ is used to lift a log, one end is placed under
the log, a block called a _fulcrum_ is placed under the lever as close
as possible to the log, and then the workman pulls down on the outer end
of the lever. For example, if the fulcrum is one foot from the log and
ten feet from the man, the latter can raise ten pounds with a pull of
one pound, but he has to move his end of the lever ten times as far as
the log rises. Try it. See other examples in plough handles, see-saw,
balance, scissors, wheel-barrow, pump-handle, handspike, crowbar,
canthook, nut-crackers.
ROPE AND PULLEY.--In the _rope_ and _pulley_ note that when the pulley
is a fixed one, the only advantage is a changed direction of the rope.
When the pulley is _movable_, the horse pulling will have only half the
weight to draw if the pulley is single, one quarter if double, one sixth
if triple, etc. Thus in the case of a common hay-fork the horse draws
only half the weight of the hay, but he walks twice as far as the hay
moves.
COGS.--If one wheel has eighty _cogs_ and the other ten, the latter will
turn eight times to the former's once.
BELT.--When a _belt_ runs over two wheels, one having, say, one fifth of
the diameter of the other, the smaller will revolve five times for one
revolution of the other.
CRANK.--With a _crank_ two feet long, one may turn a wheel twice as
easily as with one one foot long, but the hand will move twice as far.
If a wedge is two inches thick at the large end and ten inches long, a
man may lift 1000 pounds by striking the wedge a 200-lb. blow.
INCLINED PLANE.--If a plank twelve inches long has one end on the ground
and the other on a cart four inches high, one man can roll up the plank
the same weight that would require three men to lift, but he has to move
the object three times as far.
PROBLEMS
1. Why is a long-handled spade easier to dig with than a short-handled
one?
2. Which is easier, to dig when the spade is thrust full length or half
length into the earth?
3. Can a small boy "teeter" on a board against a big boy? How?
4. In helping to move a wagon, why grasp the wheel near its rim?
5. In making a balance, why should the arms be equal? In a balance with
unequal arms, compare the weights used with the article weighed.
6. In using shears, is it better to place the object you wish to cut
near the handles or near the points?
7. Where is the best place to put the load on a wheel-barrow?
8. Notice how three horses are hitched to a plough or binder.
9. Where would you grasp the pump-handle when you wish to pump (1)
easily, (2) quickly?
10. Stretch out your arm and see whether you can hold as heavy a weight
on your hand as on your elbow.
11. Count the pulleys used in a hay-fork and determine the use of each.
12. If a ton of hay is unloaded at five equal forkfuls, what weight has
the horse to draw at each load?
13. Count the cogs on the wheels of a fanning-mill, washing-machine,
apple-parer, or egg-beater, and determine how the direction or rate of
the motion is changed thereby.
14. Measure the diameter of the large fly-wheel of a thrashing-machine
engine, and of that which turns the cylinder in the separator. Decide
how many times the cylinder revolves for one turn of the fly-wheel.
15. Think of all the uses of a wedge. Draw one. Compare the axe, knife,
and chisel with the wedge.
16. How are heavy logs loaded on a sleigh or truck? How are barrels of
salt and sugar loaded and unloaded?
17. There are two hills of the same height. One has a gradual slope, the
other a steep one. Which is easier to climb? In what case is it farthest
to the top?
18. Why does a cow or horse take a zigzag path when climbing a steep
hill?