Barrow, Isaac - Lectiones opticae & geometricae : in quibus phaenomenon opticorum genuinae rationes investigantur, ac exponuntur: et generalia curvarum linearum symptomata declarantur

Scan	Original
71	53
72	54
73	55
74	56
75	57
76	58
77	59
78	60
79	61
80	62
81	63
82	64
83	65
84	66
85	67
86	68
87	69
88	70
89	71
90	72
91	73
92	74
93	75
94	76
95	77
96	78
97	79
98	80
99	81
100	82

7658

Lect. VIII.

I QUæ radiis obveniunt à longinquo puncto manantibus, adc-
óque quaſi parallelis, ex reflectione peripheriam ad circula-
rem peractâ; ubinam & quouſque vel ſibimet ipſis occurrunt, vel ax-
em interſecant; quo loco radians oculo ubicunque conſtituto repræ-
ſentant, in poſtremis eſt diſſertatum. ad punctum jam accedimus ra-
dios ejiciens ſenſibiliter divergentes. Et hujuſmodi quidem puncto,
quanquam ſeu in obverſas circuli Convexas partes ſeu ad concavas
radiet communia pleraque ſymptomata conveniunt; tamen communi
fretus _Opticorum_ exemplo, præſertímque majoris evidentiæ causâ,
caſus iſtos diſtinctè proſequemur; illum fuſiùs imprimis, hunc aliquan-
to conciſiùs. ad rem.

II. In circuli BNP (cujus centrum C) convexum à puncto A
quilibet incidat radius AN, íſque reflectatur in NG; patet reflex-
um GN productum axi AC occurſurum. nam ductâ CNE patet
GN productum angulum ANC ſecare; nec non ideò trianguli
ANC baſin AC; puta in K; quo poſito.

III. Dico fore AC. AN : : KC. KN. Nam ducatur KH ad
CN parallela. eſt igitnr ang. KHN = CNP = CNK = NKH.
hoc etiam è ſuperiùs generatim oftenſis conſectatur. adeóque NH
= NK. itâque cùm ſit AC. AN : : KC. HN. erit etiam AC.
AN : : KC. KN.

IV. Corollarii loco notetur (ductâ CP) fore NH = NK;
& triangula HNK, NCP aſſimilari; vel eſſe HK. HN : : NP.
CN.

V. Porrò, conftantibus iiſdem, dico fore AC. KC : : ACq
- ANq . CNq. Nam eſt NP. CN + AN. CN = HK.
HN + AN. CN = HK x AN. HN x CN = AN.

Page concordance

Text layer

Text normalization

Search

Scan	Original
71	53
72	54
73	55
74	56
75	57
76	58
77	59
78	60
79	61
80	62
81	63
82	64
83	65
84	66
85	67
86	68
87	69
88	70
89	71
90	72
91	73
92	74
93	75
94	76
95	77
96	78
97	79
98	80
99	81
100	82

Scan	Original
71	53
72	54
73	55
74	56
75	57
76	58
77	59
78	60
79	61
80	62
81	63
82	64
83	65
84	66
85	67
86	68
87	69
88	70
89	71
90	72
91	73
92	74
93	75
94	76
95	77
96	78
97	79
98	80
99	81
100	82

Scan	Original
71	53
72	54
73	55
74	56
75	57
76	58
77	59
78	60
79	61
80	62
81	63
82	64
83	65
84	66
85	67
86	68
87	69
88	70
89	71
90	72
91	73
92	74
93	75
94	76
95	77
96	78
97	79
98	80
99	81
100	82