Mifcellanea Curiofa. 319 



r r ~" TV^Vb thls E( l uatI " orl ftews the Que- 

 ftion to have % Anfwers, and the Roots there- 

 of are L JL + V Zl+ML _ T . 



from which I derive the following Rule. 



Divide half the Parameter by the Horizon- 

 tal diftance, and keep the Quote ; JL 



fir f Y' 3S of the S l7en t0 th e 



na ; t Parameter, fo half Parameter + double 

 height j . ■ -rr ■'. 7 



defcent to &e fquare of a Secant ==z^jr±£t 

 *-w-ti 4 ^ 



The T^ w , anfwering to that & C4 #ii, will be 



y pJ + Mb —i or Square of Radius, 



fo then the fum and difference of the afore- 

 found Quote, and this Tangent will be the Roots 

 of the Equation, and the Tangents of the Eleva- 

 tions fought. 



Note here, that in Defcents, if the Tangent 

 exceed the Quote, as it does when ph is more 

 than bb, the direction ot the lower Elevation 

 will be below the Horizon, and if phz=ibb, it 

 muft be direded Horizontal, and the Tangent 



P r 



of the upper Elevation will be ~- : Note like- 



wife, that if 4 b b -+ 4 p h in A [cents, or 4 



4 in Defcents, be equal to /> there is but 



one Elevation that can hit the OfyVH, and its 



Tangent is — . And if ^bb 4 phm A/cents, 



