332 SOME SIMPLE MACHINES IN THE HOME 



2. TO STUDY THE DIFFERENT TYPES OF WASHING MACHINES AND 



DECIDE WHICH IS BEST SUITED TO HOME USES. 



3. PROCURE HOUSEHOLD SCALES. HAVE THEM ADJUSTED BY 

 DEPARTMENT OF WEIGHTS AND MEASURES. WEIGH GROCERIES, 



MEATS, ETC., BOUGHT, AND SEE IF CORRECT WEIGHTS ARE DELIVERED. 



4. TO DETERMINE HOW A LAWN MOWER WORKS, WHAT TYPES OF 

 SIMPLE MACHINES ARE IN IT, AND APPROXIMATELY THE RELATION 

 OF POWER TO WORK. 



5. TO DETERMINE WHAT MACHINE PRINCIPLES ARE USED AND 

 HOW THEY ARE APPLIED IN THE DOOR KNOB, LATCH, AND LOCK. 



Thought Questions. 



1. May the hands of a clock be considered as machines of the 

 lever type? 



What class of lever are they, and what advantages as machines 

 have they? 



2. Explain the type of simple machine you use when you wind a 

 watch or a clock. 



Why we use machines in our homes. If we had 



lived a great many years ago, we would have found 

 that there were very few devices which enabled our an- 

 cestors to save labor in their homes. Much work was 

 done by hand, and a few simple machines, such as churns, 

 spinning wheels, wagons, and the like, were used to do 

 most of the mechanical work. In the present era, an 

 age of machinery, we have come to save time and also save 

 our own energy by using machines to help us do the work. 

 We find also that machines are usually much more effi- 

 cient than we are, and so it is that we have year by year an 

 increasing number of devices for labor saving in our homes. 

 Each year some new device is perfected, and it is a wise 

 housekeeper who can select from such a multitude of ma- 

 chines now offered in the market those which are mechani- 

 cally perfect, and serviceable and durable. It is the pur- 



