i6. YORKSHIRE. 271 



is when the load is in the cquipoife of over- 

 turning ; the entire weight of the load and 

 carriage reding at that time upon one wheel; 

 which, in that cafe, injures the road juft ns 

 much as a load of twice the weight would 



O 



do pafilng upon a level road. Whenever 

 either fide of the triangle above-defcribed is 

 brought into a perpendicular pofition, the 

 load is in the injurious equilibrium. 



Thefe prcmifes being duly confidered, it 

 is obvious that there are three ways of redu- 

 cing the perpendicularity of the line ; con- 

 fequently of prev-enting a loaded carriage 

 from being placed in fo deftruttivc and dan- 

 gerous a (late. Firft, by railing the deprcf- 

 fed corner of the triangle; that is, by bring- 

 ing the road nearer to a level : fccond, by 

 Ihortening the fides of the triangle ; that is, 

 by lowering the center of gravity of the 

 load ; or, in other words, reducing the height 

 of the carriage: third, by lengthening the 

 bafe of the triangle ; that is, by widening the 

 fpan, or placing the wheels farther afundcr. 

 Thefe things are mathematically demonilra- 

 ble; but as they muft appear obvious to every 

 one acquainted with the rudiments of fci- 



encc. 



