RECORDS 



25 



well known that all quantities used in rational mechanics are 

 commonly expressed in terms of length, mass and time. But 

 these quantities might be expressed equally well, so far as alge- 

 braical statement is concerned, in many other ways. Thus we 

 might take energy as one of the fundamental quantities instead 

 of either length, mass or time ; in which case our mechanical 



Table I. 



Table II. 



Quality 



Velocity 



Acceleration 



Force 



Momentum 



Energy 



Power 



Mass Factor. 



Af-i 



M-\ 



M+i 



Jl/+i 



A/° 



Afo 



Time Factor. 



Z-1 



z-1 



7"o 

 Z-i 



Table III. 



quantities would be expressed in terms of energy, length and 

 mass ; or of energy, length and time ; or of energy, mass and time. 

 A consideration of these simple systems shows us, among other 

 things, that rational mechanics might have been developed along 



time appear explicitly ; in the second length does not appear explicitly ; and in the 

 last, time does not appear explicitly. A glance at the exponents (dimensions) of 

 the symbols shows clearly how definite the meanings of the terms force, energy, 

 power, etc., may be in comparison with the utter ambiguity attaching to them in 

 common parlance. 



