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Sound of flight of insects. 



Step of a horse trotter, pacer. 



Sounds made by horse, cow, sheep, dog, cat. 



Hustle of leaves made by snake, lizard, mouse or bird. 



Sound ^nade by wind in leaves of different trees, spring and au- 

 tumn. 



Contrast sounds made by pines, hemlocks, birches, oa&s, chest- 

 nuts, poplars and Scotch firs; by fields of unripe and ripened 

 corn, wheat, oats and barley. 



Sound made by rain on leaves and grass. 



Rippling of a stream, dashing of waves. 



Detect any musical notes. 



1. Classification of Sound. 



1. Pleasant tones song sparrow's notes. 



2. Unpleasant noise thunder. 



II. Properties of Simple Tones. 



1. Pitch high, cricket's chirp. 



2. Intensity illustration. 



3. Duration illustration. 



III. Transmission of Sound. 



1. Gases conductor of sound. 



(a) Are sounds clearer on a warm or cold day; summer or winter; 

 colder countries or tropics; mountains or valleys; country 

 or town? 



2. Liquids; better conductors than gases. 



(a) Strike stones together under water; in air; where is sound 

 more distinct; experience of divers. 



3. Solids; better conductors than liquids. 



(a) Tap gently on a piece of wood; have another persons ten feet 

 away; listen; tap again, and have the other person put his 

 ear to the wood. In which case is the sound more distinct? 

 Why do Indians put the ear to the ground to discover a 

 footfall? Why is copper used more for telegraph and tele- 

 phone wires than iron. 



IV. Speaking Tubes. 



1. Value and Use. 



2. Ear Trumpets. 



3. Gramophones. 



V. Reflection of Sound. 



1. Compare Reflection of Sound and Reflection of Light. 



2. Echoes: cause. 



