5 1 8 Mifcellanea Curio/a. 



the Project from G to L^LX^GY ; then by 

 Reafon of the Parabola, as L X or GY, is to 

 G L or Y X, fo is G L to the Parameter fought. 

 To find the Velocity of the Imfulfe : by Prop. 2, 

 and 4, find the Time in Seconds that a Body 

 would fall the Space LX ; and by that dividing 

 the Line GL, the Quote will be the Velocity, or 

 Space moved in a Second fought, which is always 

 a mean Proportional between the Parameter^ and 

 1 6 Feet, i Inch.^ 



Prop. X. Problem i. Having the Parameter, 

 Horizontal Diftance, and Height or Defcent of 

 an ObjeHj to find the Elevations of the Line of 

 Dire&ion neceffary to hit rhe given Objeft ; that is, 

 having GM, MX, and the greateft ifrtim equal 

 to half the Parameter J to find the Angles FGB. 



Let the tangent of the Angle fought be 5=«, the 

 Horizontal Diftanoe GM=*, the Altitude of the 

 OfyVff M X the Parameter—?, and MM 

 =r.r, and it will be, 



As r to ?, fo b to — = ML and — -+» 

 r r 



Jinafonts? LX d 

 7. in defcentsj 



tii-jjl p h = G L gttfl& fc% ¥ i**f*tf 

 ParaUU\ but 



GL^W.47- *• Wherefore 



r r 



£ii X** = j £ which Equation tran- 



fpofed, is 



itf bh _^tllx pl—b b, divided by i> t is 



y j» r 



rr 



