Units of Velocity, Work, or Force. 
38 The N.Z. Journal of Science and Technology. [Feb. 
(4.) One representing the journey from the orbit of Mercury, which takes 
barely a week. 
(5.) One representing the last day’s journey before reaching the Sun, a 
stage of over ten million miles. 
Fig. 3. 
As examples of such diagrams the first and last are given (figs. 1 and 2). 
Any one of the other quantities may be taken as the independent variable 
instead of the distance. For example, in fig. 3 the others are plottedMn 
terms of the time. 
Instead of drawing curves to represent the variations, the values of the 
variables at definite points may be calculated from the equations, and the 
results given in a table. 
