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: 0.85.
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The machine reads it as
- F OC
- ac P, is asche sinc ot che respectire retracted An-, ac cach renth of an Inch distance From the AXis, the
- sle. Whence in all Cases oF Parallet RaYS, C F i5) Foci are as FolloWS.
- EOP F, in che lame constant Rario ot Retraction.
- IF ic Mall be desired ro effect in Numbers wtar
- re hare here done by Lines, ic will be most casie
- to adapt a Calculus ro the toresoins Ceomerrical.
- Construction.
- For it in che Frianele PO C, there De given the
- Radius C P equal 1o Vniey, CO che Distance ot
- the Object From che Centre of the Sphere, and che
- Perpendiculat P x, equal ro the Siné oF che Anole
- P CO, che Side PO = OR, will be equat EO
- VEO FCP F 2COin VCP =PF
- Then aS OR OF PO EO P x:: So C R 10 che
- Sinc oF the Angle C OR, and the Complemenero
- 180 Degrees ofthe Sum of the Angles C PO and
- COR, is ihc Ansle C R Q equal C F P; and a5
- P X 1O PO, (0 is the Sine OF the Anple C RO EO
- CQ; and aS C QTO C. P, IOC REOC F, which
- is the Distance of the respectire Focus oF ai the
- RayS P O from the Centre oF che Sphere C.
- Burche Foci oE Rays parallel roThe AXIS, may
- De compured more readily follomine rhe Foorexs
- ot che Construction, For chereby ic ill appear,
- Mharche Radius oE che Cirele H F, viZ. a F, 15 c.
- qualeo- C P, and C a = = CP,
- For Fmersins RayS, a5 in Fis. I. but For Tmmer-
- sins RaYS, 25 in Fis. 2. C a will be tound to be
- ==C P: And supposins che Distance oF he
- RayS From che AXis = P X, in the CasC OF Parallel
- RayS Fmergins, rhe Distance of theFocus will be
- Found,
- PF =
- Thatis, r 2O s Beins a5 3 102,
- PF= SV CP = ex L VECP =3P~
- And Cor Immersins Rays, the Focal Distance i
- Coundby alitre Rule:
- PF
- er
- CP = L +
- er = 55 CP = er - 55 x C P.
- Thac is, r and s bcins 25 3 102, 25 betore.
- PF = 3 V CF = Pv F V5CP -2P~
- CF
- These Canons are (0 casly deduced From che
- Constructions, thacchere is no necd corrouble che
- Reader wich cheir Demonstrarions, onty vou have
- here added ero Fables compured trom them, wwirhr
- lirele more Work than a continual Addirion; wtrick
- may by ar of Example, serre ro instruet and ex
- ercileche rouns Scudene in chis parr ot che Mache-
- Cussiciene Satisfaction.
- FODTNTA, is the Labyrinch in che BMC OE the
- RaES.
- FAECOTA, Signities a Poder erhich subsidesto
- maricks.
- Suppole CP ihe Ractius ot ihe Sphere or Ctass) Porder whichis ro be aryed lixhely
- 2 Ineties, and che Rario ot Retraction 25 3 202;
- ILKK 2
- si A C
- Por Fmersine Rays.
- 2. 92.76+ V 5. 7276
- V 12. 8304 + V 5.6304. 2
- V 12.6634. + V 5. 4684: L
- V 12. 4.4. 16 +- V 5. 2.4.16.2
- 12. 1500 = V 4. 9500 2
- VTT. 7936+ V 4. 5936.2
- IT. 3724 + V 4. 1724
- V 10. 3864. + V 3,6864.
- V 10. 3356 + Y31356-2
- V 9. 7200.+ V 2.. 5200-
- For Immergins Rays.
- 4. V5. 7344 +
- V2.5024 + V5. 7024+
- V 2. 4576 + v5.6576+
- 4000 + V5.6000.+
- 2.3296 V5. 5296.+
- V2. 2.464 + V5
- V 2. 1504
- V
- V2.04.16 + V5.
- 10 lV 1. 9200 + V5. 1200+2
- Butic is co be Nored, Thac these Foci For Im.
- mergins Rars must nor be caken For the Foci OF a
- Llano Correa, en n cnreau ls comards
- the Object, For che Plane- Side by irs Retractian
- does conrraet the Focal Lengch, by about a semi-
- diamerer dt elle oplele, cele lupose bous
- et Clals concinued.
- The Came Ingenious Author, as an Inltance
- the Lxcellence oF che Modern Algebrae, gires al(o
- in Philos. Fransact. N. 205, a Way ro And the Foci
- Ot all prick Colasses univertally; and ews oF
- Wrhar sieat usc his and tuch Theorems are: BUE
- lavins cMlarsed (o muest altcaus, L Cast only reter
- ee Alsebraieat leacer c, where he will ind
- the Borrom in cerrain Hraimings of Vegetables;
- For ic is prepared ot lome ercen, wathed, alu pa-
- red Roors Deac rogether ich a licrle WVarer, then
- Strained, that chere may sublide a evtrire Tort ob
- EOEKVS,
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/806933011:0351?run=74