366 REVIEW. 



Recapitulation.-^In this section we have considered 

 the definition of Thermodynamics ; the Corre- 

 lation of Heat and Mechanical Energy ; 

 heat from Percussion ; from Friction ; First 

 Law of thermodynamics; Joule's Equivalent 

 and its Use; Chemical Affinity and the Heat- 

 ing Powers of various substances ; the Single and 

 Double-acting Steam-engines ; the Eccen- 

 tric, Governor and Safety-valve ; Condens- 

 ing and Non-condensing Engines; the relation 

 between Heat and Work in the steam-engine. 



REVIEW QUESTIONS AND EXERCISES. 



1. Lead melts at 326 C. In melting it absorbs about as much 

 heat as would warm 5.37 times its weight of water 1C. What 

 numbers will replace the 326 and 5.37 when the Fahrenheit scale is 

 used? 



2. What is the difference between the temperatures 40 C. and 

 -40 F. ? 



3. A quantity of gas at 100 C. and under a pressure of 750 mm. of 

 mercury measures 4500 cu. cm. What will be its volume at 200 C C. 

 and under a pressure of 76 cm. of mercury ? 



4. Over how high a ridge can you carry water in a siphon, where 

 the minimum range of the barometer is 27 inches ? Explain. 



5. (a.) What is Specific Gravity ? (&.) How do you find that of solids 

 heavier than water? (c.) What principle is involved in your method ? 



6. (a.) Of what physical force is lightning a manifestation? (b.) 

 Give some plain directions for the construction of lightning-rods, 

 with reasons for your directions. 



7. Give the fundamental principle of mechanics, and illustrate its 

 application by one of the mechanical powers. 



8. (a.) What are the essential properties of matter? (&.) What is a 

 pendulum ; (c.) to what use is it principally applied, and (d.) what 

 are the laws by which it is governed ? 



9. (a.) In what ways may two musical tones differ ? (&.) What is 

 the physical cause of the difference in each case ? 



10. (a.) Convert -3 F. and 77 F. into C. readings ; (&.) 18 

 and 20 C. to F. readings. 



