Full text: Barrow, Isaac: Lectiones Opticæ & Geometricæ

& demittatur NQ ad AC perpendicularis, erit CQ = F - E. ‖
Nam (ut ſuprà) eft CA. CK: : F. E. quare dividendo erit CA
- CK. CK: : F - E. E. Item hîc erit ANq - ACq =
2 AC x CQ + CNq. adeóque 2 AC x CQ + CNq. CNq
: : AC. CK. hoc eſt, (ob CNq = 2 AC x E.) 2 AC x CQ
+ 2 AC x E. 2 AC x E: : AC. CK. hoc eſt CQ + E. E: :
AC. CK. quare dividendo CQ. E: : AC - CK. CK. ergo
F - E = CQ: Q. E. D.

IX. porrò, ſi duorum quorumvis radiorum AN, AR reflexi
NK, RL axem ſecent punctis K, L; erit CK. CL: : ARq -
ACq. ANq - ACq. Nam ob CK. AC: : CNq. ANq
- ACq. & AC. CL: : ARq - ACq. CNq. erit ex æquo
perturbatè CK. CL: : ARq - ACq. ANq - ACq.

X. Hinc ſi radius AR ſit ipſo AN obliquior; erit CK & lt; CL. Nam ARq - ACq & lt; ANq - ACq.

XI. Hinc palàm eſt reflexos NK, RL ſeſe priùs quàm axem
decuſſare.

XII. Accipiantur porrò bini pares arcus NR, RX; & inciden-
tium AN, AR, AX reflexi cum axe conveniant punctis K, L, M; dico ſpatium LM, obliquiorum occurſibus interjectum, majus eſſe
ſpatio LK, quod rectiorum continetur occurſibus. Nam è ſuprà
monſtratis conſtat eſſe ANq + AXq & lt; 2 ARq. proindeque fo-
re ANq + AXq - 2 ACq & lt; 2 ARq - 2 ACq. ac indè
ANq. - ACq. ARq - ACq & lt; ARq - ACq. AXq -
ACq. hoc eſt CL. CK & lt; CM. CL. vel CM. CL & gt; CL. CK. quare CM + CK & gt; 2 CL. & ideò LM & gt; KL.

19.1.

Fig. 102;

XIII. Hinc rectiùs ingruens lux à reflectione verſus axem conden-
fatior evadit.

XIV. Quidnì demùm rurſus ex his inferatur, viſibilis A imaginem
@irca reflexorum metam Z, oculo uſpiam in AZ conſtituto, appa-
rere?

XV. Adverſatur ſaltem (id quod experiendo deprehendetur) ocu-
lo uſpiam in ZB collocato confuſiorem apparentiam objici; quippe

Waiting...

Note to user

Dear user,

In response to current developments in the web technology used by the Goobi viewer, the software no longer supports your browser.

Please use one of the following browsers to display this page correctly.

Thank you.

powered by Goobi viewer