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: 0.88.
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The machine reads it as
- R
- eR OPOSTTION H
- IF Four Ouantities are proporrional, cithex con-
- cinualle or dilereetly, che Produet oE che fixtremes
- is equalto rhe Product oF the MeanS.
- For il an ray rray rera, in Or 2. 4. 8. 16. .
- ris plain che Produet oF the Extremes and oF che
- Vleans, is rhe same Ouanrity rrraa OF 32.
- In Discreer Proporionals, let a: ra:: b: rb;
- that 15, 2: 4 : : 15 : 30. The Product OF the FX-
- treams ard of che Means can here beno orhet char
- ab = 60.
- On Wohich Proporrion is grounded che Colden
- Rule, Or Rule of Threc in Arithmerick; (0 called,
- because havins Threc NTumbers, (25 2. 4. 25.) ic
- ceaches hion to find an VInKHOWn FOUrtH PFOPOT-
- tional: For altho this Fourth be unknon, yec ic
- Produet bV 2, cheFirst Perm, is knomn, becaule ris
- the lame wich the Product oF che McanS + and 15.
- Wheretore che Rule directo us ro multiply che
- Third by che Sccond, chac rou may chereby ob-
- tain the Product oF che Extremes; wtrich dirided
- by onc oF the Fxrremes, viz. the First, must necds
- sire cheorher, that is, the Fourch Toughes
- COROLEREES
- Etence vis plain, Thar iC. Lvo Products arisine
- From che Nulriplication ot any LWo Pairs oF Onan-
- ecies, are equal; chose Four Ouantiries will Be ac
- cast diserecels proportional.
- PROPOSITION HI
- IE chere are never somany Continual Proponion-
- als, the Produet oF the Lxrremes is equal eo the
- Produst oF any Two OF the MeanS Thar arc equa-
- Iy distant trom che Farremes, 25 al(0 to ehe Square
- ot che Mean or Midale Term, il che. Number ot
- the Permsbe odd. le
- Thus in etis ecogresion,
- 2 4 8 16 32, 64 128.
- a. ra. rra. rrras rrra. rrerra. rrerrra. c.
- IEs plain che Product dE tHC PXIreMeS, and oE any
- Tuo Terms equally distane from them, and che
- Square oF ihe Midalo Term, must alwarsibe
- 6aa.
- As Etie las Tertm bue one, is muliiplied into 2
- DeEreC OF POWer OF the Ratio lels By One than chC
- last; (0 ehie Second Term is mulciplied into one
- more than ehe First: And cheretore che Rectangle
- OF thie Fxtremes mus RilI De che Tame Ouantity
- wich chat of the Product of any Tvo Terms c.
- quallu distant from chat; and chis also equal ro che
- Square oF the Midale Lerm, it the Number ot
- ehem be odd.
- P R O POSF Y LO NmA
- Flaviris rhe First and Last Ferms, and ete Rario;
- Tofind the Sum os all the Terms in any Ceometrical
- Proeression, MI. Ousbtred siveschis Mertod.
- Let a beche sirst Perm, andy the last; etien let
- all the antecedents, and Z = a = 3Il che
- Consequents. Theretore, by Compolition oF Pro-
- porcion, ic plainls CoHlows, Thar a. ra : Z 7
- LeF F F (OF rb) be a Mean Proporional DC
- Eveen the Side oF the Cone B C, (OF rrb;) atic
- ihie Radius oF rhe Basc CD, (Or b;) and let
- etiere be an equal Number oF Peripheries, rra
- ra, and a artiverine 10 un equal Nuiber OF Ra
- dii in che lame proxorrion; then Wvill halt che firte
- Radius B C, (Ox rr B) mulciplied inco the Peri-
- phery a, (thac is = rr a b) be equal ro halF che
- eroaut ot uhe midase Line imco chemidale Peri
- pherr, chat is (as Betore) halt rrab: The FOF
- irier ot wrhich is equal co che surtace oF the Given
- Cone, (by the Ach Cons. OF his De. 18.) and ehie
- latter ro the Area oF che Circle, Wio Lacius I5
- the Mean Proporion EF, (by rhe 2dC09. et tii
- Def. 15.) 8. F. D.
- Ana Trom hence also Rous naturally chis orhet
- Proxotirion, That the Sursace B sc Lo, Bals L lL b,
- os s Base hals 2b; ac the Side ef the Cone P F
- s to obe Radius es che Pasc b. F0r
- Errab: ab:: rrb: b.
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/806933011:0661?run=74