Lexicon Technicum: Or, An Universal English Dictionary Of Arts And Sciences, fol. -
Machine transcription. Not an edition. Errors are expected: about 8% character error rate on Latin and French lines, higher on German. Mean line confidence on this page: 0.87.
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The machine reads it as
- IIL. I a Scalenous Cone ABC DE Cut B LEuta
- in a subcontrary Position to its Base, the Sectu
- DEH nou be a C irelem
- Ra75.
- 4. An Olique Circle, votiose Plane lies osde le
- 3. A Rixht Circle, vohose Plare is coincidete
- Axis oE 23 et WM EnC VIUa
- che AXis oF che Fre, P0 chac ic makes unequal An-
- 8les wich ir
- Fo Project the Sphere truly in Plano, is a PAFF OF
- Perspective; Whereot chere are several kinds; bui
- the most usual is what is proxerty called the Stereo:
- graphicte, Ox Solid Projection of the Sphere; aud the
- Orthorraphick, or che analemma: The Lallet Ot
- ertrich, sec in analemma.
- Inche Former, che Circles ot thelo atc arabon
- ex reprelenced on a Plane, erhich passes cibuph
- irs Center, and hach the Fye, supporec ro be in
- che Pole or 900 distant from ic; Poechine the lere
- ral Circles or Arks oF Circles on char Planc, Ox on
- any one parallel to it.
- In ehis Projection, it a Line pals Mouph che
- Fiye, or be coincident or Palatus d C XIS, ir wil
- be represented by a Point.
- IV. Is a Line be direct 1o the Ereq it ill be pro–
- i
- 1. The Section A BC made chroust che Axis,
- is a Friangle.
- 2. The Friangle A F D is Similar E0 A B C,
- tho placed a contrary ray, (by che Supposion)
- (Whichis called Subcontrary Posicion.))
- 3. F D beins the mutual Intersection OF EO
- Planes wilt be a Riphr Linc, on Which cake any
- PoinE, 25 (i) and chroueh ic deaw F i C parallel 10
- BC, and ehere ler the Cone be cur al(o, etien the
- Plane chac curs ic beins parallel 1o che Bale oF the
- Section, P HIC must be a Circle, and F C a Dia-
- meter.
- Nou, because boch chele Interlectine Planes
- arc Righero che Plane ot che Triangle AB C theix
- common Incersection IFI, Will allo be a Righe
- Linc, and perpendicular co the Plane oF che Fri
- anele, and eo the rvo Lines P D and FC. And
- then, because che Triansles ABC, A B D and
- A F C arc all Similar, che Angles at C and P must
- be equal; and che Verrical ones at i beins (0r00,
- che Triansse F P I must be Similar e0 ID.
- Wheretore D I: IG : : F I: T F. theretore
- IDIE = () FIG5 bur because F C is the
- Diameter oF a Cirele, and I FI perpendicular ro it,
- and cerminared ac che Circumterenco, twill be a
- midole Proportional berreen the Segments of the
- Diameter, and hare ies Square equal ro the Rect.
- angle FIG, (a5 aI(0 eO iEs Bqual F ID) where-
- Fore che Poine II is in the Circumterence of a Cir-
- cle, wohose Diameter is D F. 8. F. D.
- DEFENETIONT
- ACirole of the Sphere, as eo its Projection on any
- Plane, is oF tour Kincs.
- I. The Primitive Circlo, or Limb ehich bounds
- ehe Projection, and wichin wrtich ris alvars
- made.
- 2. A Direct Circle, whole Plane is directiy oppo-
- sirero che Fyc, or iotien che Ere is in chc Axis ot
- The Plane.
- merer ot a larallel Circle) is luppolea cone lalal
- telto D F, and is projected into ir from the Lye at
- A, il rou deaw rhe LineS AD, A F, and AF, che
- Triangles ABC and AD F will be Similar; 25
- also will A CFC and A F F; Wheretore aS AB
- AD:: BC: D F. and as AB: AD:: AC3
- (+ L. dd L 5 2L~:: BC: DP :: C
- L F. Trasct ad CHC. Wose BC Wo che Wvhole
- F 116 L at BL.. 6C.
- sected into a t LMe, nisse lals be in
- the same Proporrion to one another, as those os
- the Primitive Line, os which it is the Repre-
- sentation.
- Fo, Since The Line B C (WIIICM LLIA) DE LHCBIa-
- PRO
Cite
Lexicon Technicum: Or, An Universal English Dictionary Of Arts And Sciences, fol. - . Machine transcription, not an edition: Leibniz Legible (model FoNDUE-GD_v2_ft_Leibniz, run 74). https://leibnizlegible.com/page/806933011:0759?run=74