376188v
Corollarium. 4m.
Si agatur , erit parallegrammum, et æqualiumum laterum, et ideo
rhombus. (vel quadrati.)
cum sit æqualis , si agatur et producatur versus .
per conicorum elementum tanget sectionem in puncto.
et si producetur versus . rectæ et facient æqualis
angulos cum contingente . hoc est, angulus
nam: .
Inde obiter patet ratio speculi parabolici comburentis, de quo
[Translation: Corollary 4.
If there is constructe , then will be a parallelogram, and of equal sides, and therefore a rhombus (or square).
Since is equal to , if is ocnstructed and extended towards , by the elements of conics it will touch the section in the point .
And if is extended towards , the lines and make equal angles with the tangent , that is, angle , for .
Whence is clear the reason for the parabolic mirror for combustion, of which ]
Si agatur , erit parallegrammum, et æqualiumum laterum, et ideo
rhombus. (vel quadrati.)
cum sit æqualis , si agatur et producatur versus .
per conicorum elementum tanget sectionem in puncto.
et si producetur versus . rectæ et facient æqualis
angulos cum contingente . hoc est, angulus
nam: .
Inde obiter patet ratio speculi parabolici comburentis, de quo
[Translation: Corollary 4.
If there is constructe , then will be a parallelogram, and of equal sides, and therefore a rhombus (or square).
Since is equal to , if is ocnstructed and extended towards , by the elements of conics it will touch the section in the point .
And if is extended towards , the lines and make equal angles with the tangent , that is, angle , for .
Whence is clear the reason for the parabolic mirror for combustion, of which ]