EXTERNAL FORCES 



31 



only one way for doing anything is apt to be dogmatic and think 

 his way alone is right. An ingenious man will discover for himself 



Fig. 24 Graphical Method for Constructing Parabola 



many ways to shorten his work when he knows he is not compelled 

 to adhere to some method he has been shown. 



When the height of the parabola is greater than the span more 

 accurate results may be obtained than when the height and span 

 are nearly equal, or when the height is less than the span. Use 

 a scale that will give results with the accuracy required for the 

 work. In some work the height of the parabola may be much 



Fig. 25 Graphical Solution for One Concentrated Load 

 Resting on a Beam 



than the span and still give results sufficiently accurate. 

 When the height of the parabola is not greater than one-tenth 



