June 28, 1918] 



SCIENCE 



643 



Total expected output = 1,620,000 barrels = 100 



per cent. 



Output up to January 5, 1918 = 227,000 barrels := 



14 per cent. 



We can see readily that no conclusions what- 

 ever could be drawn as to the output rate or 

 as to the actual number of barrels of flour 



The expected output after having been care- 

 fully calculated is based on a uniform pro- 

 duction rate throughout the given time. 

 Graphically expressed the requirements or the 

 expected output are a straight line, the tangent 

 of which is the production rate or as shown in 

 Fig. 2. 



7*JV^ er^scrro ^'ff^ffcr/a/v ofira fsaS- " ■C^2a,ffaa y3B^s. 



i>o% , 



^. 



^ 



which should have been manufactured up to 

 January 5, 1918, if the goal is to be reached 

 on February 9, 1918. Besides that the bar 

 diagram requires each time, when the output 

 has been increased, a new calculation of the 

 output in percentage of the total expected 

 output. 



To overcome this difficulty and especially to 

 avoid the constant recalculation and redrawing 

 of the bars a more efficient graphic method was 

 devised. The new method with its new dia- 

 gram automatically takes care of the whole 

 period in which production is expected. 



tga = 



Total expected production _ AB 

 CB 



Total time 



= 270,000 bbls. per week. 



Based on this average uniform production rate 

 the total required production at the end of the 

 sixth week (February 9, 1918) would be 



270,000 X 6 = 1,620,000 barrels. 

 For any time interval the total expected pro- 

 duction can be easily deducted from the follow- 

 ing proportion (Fig. 2) : 



CB:BA = C¥:FG, 

 FG being z, 



