15. Show that caloric is inherent in matter by instances of its presence in very cold bodies; also instance its being made manifest by friction and natural phenomena.

16. Illustrate cohesion and caloric as antagonistic by an account of water in its three conditions, solid, liquid, and gaseous. Name, also, one or more other instances.

17. Explain why heated air ascends.

18. Explain the process of freezing as partially an exception to the law that "Heat expands all matter."

19. Explain inertia, or persistence, as a property of matter in its application, (1) to bodies at rest, and (2) in motion.

20. Give familiar illustrations of this property of matter.

21. Explain compressibility and elasticity as properties of matter. 22. Give instances of bodies in which these properties are manifest; and of others in which they may with difficulty be traced.

2. NATURAL PHILOSOPHY.

II. THE ATTRACTIONS.

1. Name three kinds of attraction, and explain the names respectively given to them.

2. Explain gravity as a property of matter, i.e. that all bodies exercise a mutually attractive force upon each other.

3. Give familiar instances of this mutually attractive force.

4. Explain the circumstance of an apple falling from a tree to the ground upon being detached from the stem.

5. From this property explain the globular form that bodies assume in a state of freedom (i. e. free from external influence).

6. Explain the familiar instances: drops of rain; and the manufacture of shot.

7. State what is exactly meant by the law of matter called "attraction of gravitation."

8. What is "centre of gravity," with reference to a body in a state of freedom?

9. As the great attraction of the earth renders all other attractions unimportant, what is meant by the "line of gravity or attraction" in the cases of fixed or falling bodies?

10. Give an account of the plumbline and its use, in illustration of attraction of gravitation.

11. Explain the familiar instances: rope dancers; loaded vehicles upon inclined planes.

12. Describe the principle accurately in the case of a ball rolling down hill; and the dictum, " Water finds its level.”

13. Upon what fixed principle does this law of attraction act; and at what ratio according to distance ?

14. Illustrate this law by its application to radiation; the rays proceeding from a lighted candle upon a flat surface at the distances of two, three, and four inches respectively; and draw a diagram in illustration.

15. What ratio of heat will two persons have, one standing two feet from the fire, and the other four feet? also what ratio of attraction does the earth exercise upon the top of Mont Blanc (three miles high), and upon the top of a tower 100 feet high?

16. What is meant by centrifugal force? Give a familiar instance of it as opposed to attraction of gravitation (or centripetal force); and explain how the combined forces form planetary rotation.

17. What is attraction of cohesion? and in what conditions of matter is it strong? in, what weak? and in what scarcely perceptible? 18. Give familiar instances of this attraction.

19. Explain capillary attraction; and state exactly what it is from the experiment of placing fine tubes of glass in water, and the result. 20. Explain the principle and its mode of action in the following instances:

A. A towel with its end in a basin of water.

B. Damp on walls of houses, &c.

3. NATURAL PHILOSOPHY.

III. PNEUMATICS.

1. Show that air is a material substance from its properties; also give instances of its great force under certain circumstances.

2. Give a short account of the investigations by which it was proved that air possesses weight, and the exact weight it possesses.

3. What is the weight of a column of air upon a square inch of

surface upon the sea-shore? and what is the weight of air upon the human body of ordinary size?

4. By what experiment may the weight of air be felt? and why do we not feel its weight?

5. How high above the earth is the air supposed to extend? and where is it most dense? Illustrate this by comparison with piles of other substances; and from the property of matter, compressibility.

6. What is the weight of air upon a square inch of surface at the height of three miles above the level of the sea?

7. Explain the process by which a soap bubble ascends into the air; and illustrate by comparison with a piece of wood in water.

8. Why does a piece of wood fall quickly in air, and a thin piece of paper slowly? By what simple experiment may this be shown?

9. Explain the construction of balloons, and give a short account of them. Also state the greatest height ever attained.

10. Draw a diagram illustrating the construction of a common pump. Also state the height water will ascend, and the reason.

11. By what simple experiment may the elasticity of air (as a gaseous body) be shown? Explain "indefinite expansibility."

12. Explain "evaporation." What is the amount of moisture in a general way, held in solution by the air (i. e. what portion of the weight of air is really the moisture held in solution)?

13. If a glass of cold water be brought into a warm room, what will be noticed on the outside of the glass? and whence does it come?

14. Mention natural phenomena illustrating the same principle. 15. In what conditions of temperature can air hold most water? What proportion of water can air hold in solution, heated to 212° (i. e. the temperature of boiling water)?

16. When heated air, holding water in solution, meets with a change of temperature, what takes place? From this explain the source of rivers from high mountains.

17. Explain how air is not always of the same weight, heavier at some times than at others.

18. Explain the construction of an instrument for ascertaining the varying weight of air.

19. What height must a column of mercury be, to be exactly equal to a column of the air upon an equal base (i. e. to what height will the pressure of the atmosphere sustain a column of mercury)?

20. As the air becomes lighter (by ascending, and thus leaving part of the air underneath), or heavier (by holding water in solution), what effect will take place in the column of mercury? hence state the use of the barometer.

21. How is sound transmitted through the air? and how fast does it travel? Illustrate by comparisons.

4. NATURAL PHILOSOPHY.

IV. HEAT.

1. Define heat as a property of matter with reference to atoms. 2. Name an external source of heat; and show the radiation of heat, and its reflection by instances.

3. What theory is founded upon the fact of the gradual increase of temperature in deep mines?

4. What is meant by latent heat? Give familiar illustrations of it. 5. What connexion exists between what is called latent heat, and the capacity of bodies for retaining heat? Illustrate this by the instance of powdered ice and salt mixed together, and the intense cold produced. Name also other instances.

6. Heat exercises an expansive force upon bodies. What experiment will show the expansion by heat of—

A. Solids.

B. Liquids.

C. Gases?

7. Explain the construction of an instrument for measuring the degrees of heat, and its name.

8. Name the two unvarying temperatures of water which are taken as guides in making the degrees on the thermometer.

9. What points are fixed for these two temperatures upon the common scale, Fahrenheit's? And what points on the centigrade? What advantage does the latter possess?

10. Show how any number of degrees in one scale may be reduced to the other.

11. Mention the degrees (Fahrenheit) at which mercury boils and freezes; also, at which iron melts.

12. Prove the different expansibilities of solids by heat, and show how this principle is applied in the construction of machines, watches, &c.

13. Explain the irregularity of the expansion and contraction in the case of freezing water; the contraction up to a certain point; then the alteration; afterwards the rapid expansion.

14. Give illustrations of what would be the state of the water if the law of contraction were unvarying; and hence, what would be the state of the world at large.

15. Give instances of the enormous expansive power of freezing water.

16. Why does deep water not become frozen; as the deep sea; the lakes of North America, &c.?

17. State the reason of smoke ascending in a chimney; and illustrate by comparison with a body floating in a medium of equal density.

18. What causes the trade winds! Hence, how is it that they blow N.E. and S.E. instead of N. and S.? Illustrate this by a diagram.

19. What is meant by transmission of heat? Show by a simple experiment difference in power of transmission; and name good and bad conductors of heat.

20. Give familiar instances of this, and explain the following natural phenomena.

A. The sea breeze in tropical countries alternating with the

land breeze.

B. Sea coast being warmer than interior countries in winter,

and vice versa.

21. Account for the decrease of temperature in ascending from the lower to the higher regions of the atmosphere.

5. NATURAL PHILOSOPHY.

V. LIGHT.

1. State accurately the two theories about light and its origin. And give reasons for preferring what may be called the wave theory to that of Sir Isaac Newton.

2. Give a short account of the discovery of the speed at which light travels, and state the speed.

3. How long is a ray of light in coming from the sun to the earth? Also, to Neptune?

4. In what direction do rays of light proceed from luminous bodies? Show that they do not interfere with each other.

5. Distinguish accurately the following three conditions of rays, and give instances of each :