ELUCIDATIONS. 
-17 
which iiecelHty has compelled me to apply. On this, however, 
the Reader miUL cxercife his own judgement, after the following 
expolition of the Jr7/4% o.iid the rules by which I have determined 
the fcale. 
It will eafily be conceived by the Reader, that all roads, ex- 
cept fuch as are made through a country, in v/hich the public 
works are in the higheft ftate of improvement, and where alfo 
the face of it is perfe6:ly level (the curvature of the earth ex- 
cepted) muft have fome degree of inflexion, both horizontally 
and vertically; and either of thefe will occafion a Traveller to 
trace a line of greater length by the road, than can be meafured 
on a ftraight line, drawn from the point of commencement, to 
that of the termination of his journey. The quantity of the dif- 
ference muft vary with the nature of the country ; but in ordi- 
nary cafes, ftill more with the extent of the line of diftance : for 
a different ratio between the road diftance and horizontal diftance 
muft obtain, as the line of diftance is increafed. Let it be ad- 
mitted, that in ftages of ten or twelve miles, the winding of the 
road occafions a lofs of only one-tenth part, which may be termed 
the fimple winding: yet as the different ftages in an extent of 
100 or 150 miles, do not lie in a ftraight line, drawn throu^i 
the whole extent, but often very far to the right and left of it, 
F f a com^ 
