II.} 



IIANICS. 



11. /'.What name has been g: 

 the force we have lo overcome, sustain, or 

 or, in other words, the body which 



It is technically termed the weight. 



1-j. T. Why is it called the weL 

 /'. Because we can always obtain a 

 weight of equivalent effect. 



/'. What is the force which is em- 

 ployed to overcome, oppose, or sustain, 

 term 



P. It in technically called the power, 

 and communicates motion to the 1 



/'.Then you would imply that the 

 sustains the weight. 



~t: il to say so, but this is not 

 actually the case, because it is quite im- 

 .- for the power of an ounce to sup- 

 port the weight of two thousand pounds. 

 w it cannot do so. yet by employing 

 :ue it appears to do so. 



/'. How can you account for this ? 

 1\ Kvcry machine has certain 

 points, and it is so managed or contrived 

 that the pressure caused by the applied 

 weight or power, or both, shall be thrown 

 ie fixed points of the machine. It 

 can be so arranged that the greater part of 

 the weight shall 1 <1 amon- tin- 



fixed points, and that the remaining part 

 shall not be greater than the power em- 

 refore we can now 



understand how one ounce apprart to sup- 

 <> thousand pounds, and when we 

 learn more about mechanic powers this 

 will be more easily understood. 



/'. What do you mean by ID- 

 pow< r 



P. The most simple ma< ' 



II VSH 



H. which ar 



thr-c in n 2, the 



Pulley or Cord ; 3, the Inclined Plant, All 



simple machines belong to one or 



.asses; and all complex machines, 

 r large, are only made up of part* 



which are simple in themselves, and cume 



under these three mechanic p<> 



17. T. Have these p< <'d any 



particular name from philosop 



P. Yes ; they are called the Primary 

 Mechanical Power*, from winch ail 

 are derived. 



/'. How many other mechanic 

 powers are there ? 



P. 'Ihree: 1. The wheel and n 

 :om the Lei 



ncd Pltine. S. The srrcu-, iiom the 

 Inclined Plane. 



19. r. What are these powers called f 

 P. The Secondary Mechanical Power* 



20. T. How many mechanic powers 

 are tin 



/'.Three Primary and three Secondary; 

 in nil, six, from which are deri\ 

 elements of every kind of machinery. 



!IAL QUESTIONS ON LESS 



1 Kxplain what is meant by Mechanic?. 

 J. \\':i.t is the derivation of the word 

 Mechan 



3. What is a mac 



\plain the difference betwe< 

 chanics and i: 



.".. 11 has the science of Mechanics 

 . idcd by some philosop 

 \jil.iin the meanings ami <i. : ivations 

 statics and dyi 



7. What are the 



in mind in the application of machines ? 



8. Dclini- the t< : and power. 



'.' \\ :, r m mtc-hanic powers, and how 



an- there ? 



lt. How are the mechanic powers di- 



' 



LESSON II. 



FEROUSOW Is an admirable example for us all. The young should endeav< 



his zml : liahiii, humility, and perseverance; and the 



and that love of practical knovtedgt 

 only, which some persons extol so high uson's case, it waa his misf 



