<1r>

June 13th 1676.

Dignissime {|Vir|}

{|Quanquam D. Leibnitij, modestia|} in excerptis quæ ex Epistola ejus ad me {|nuper misisti nostratibus|} multum tribuat circa speculationem {|quandam infinitarū|} serierum de quâ jam cœpit esse rumor: nullus dubito tamen quin ille, non tantum (quod asserit) methodum reducendi quantitates quascunqꝫ in ejusmodi series, sed et varia compendia, fortè nostris similia, si non et meliora, adinvenerit. Quoniam tamen ea scire pervelit quæ ab Anglis hâc in re inventa sunt, et ipse ante annos aliquot in hanc speculationem inciderim: ut votis ejus aliqua saltern ex parte satisfacerem \iam/, nonnulla eor{illeg}|u|m quæ mihi occurrerun{illeg}|t|, ad et \te/ transmisi.

Fractiones in infinitas series reducu\o/ntur ꝑ divisionem et quantitates radicales ꝑ Extractionem radicum, perindè instituendo operationes istas in speciebus ac {in}stitui solent in decimali{illeg}|b|us numeris. Hæc sunt fundamenta harum reductionum; sed extractiones radicum multum abbreviantur ꝑ hoc Theorema.

P+P⁢Q‾mn=Pmn+mn⁢A⁢Q+m−n2⁢n⁢B⁢Q+m−2⁢n3⁢n⁢C⁢Q+m−3⁢n4⁢n⁢D⁢Q+&c.
Ubi P+P⁢Q significat quantitatem cujus radix vel etiam dimentio qu{illeg}|æ|vis vel radix dimensionis investiganda est. P primum terminum quantitatis ejus, Q reliquos terminos divisos ꝑ primum, & mn numeralem indicem dimensionis ipsius P+P⁢Q sive dimentio illa integra sit, sive (ut ita loquar) fracta, sive affermativa, sive negativa. Nam sicut Analycæ {sic} pro a⁢a \a⁢a⁢a/ &c scribere solent a2, a3, sic ego pro a, a3, c.a5 &c scribo a12, a32, a53, & pro 1a, 1a⁢a, 1a3 scribo a−1, a−2, a−3. Et sic pro a⁢ac:a3+b⁢b⁢x‾ scribo a⁢a×a3+b⁢b⁢x‾−13, & pro a⁢a⁢b.c:a3+b⁢b⁢x×a3+b⁢b⁢x‾ scribo a⁢a⁢b×a3+b⁢b⁢x‾−23: in quo ultimo casu si a3+b⁢b⁢x‾−23 conciapiatur esse P+P⁢Q‾mn in Regulâ; erit P=a3, Q=b⁢b⁢xa3, m=−2, & n=3. Deniqꝫ pro terminis inter operandum {illeg} inventis in Quoto, usurpo A, B, C, D &c nempe A pro primo termino Pmn, B pro secundo mn⁢A⁢Q & sic deinceps. Cæterum usus Regulæ patebit Exemplis.

Exempl: 1. Est |c⁢c+x⁢x|‾seuc⁢c+x⁢x‾12=c+x⁢x2⁢c−x48⁢c3+x616⁢c5−5⁢x8128⁢c7 +7⁢x10256⁢a9+&c.. Nam in hoc casu est P=c⁢c, Q=x⁢xc⁢c, m=1, n=2, A=Pmn=c⁢c‾12=c. B=mn⁢A⁢Q=x⁢x2⁢c. C=m−n2⁢n⁢B⁢Q=−x48⁢c3, & sic deinceps.

Exempl: 2. Est ⑤c5+c4⁢x−x5‾i.e.c5+c4⁢x−x5‾15=c+c4⁢x−x55⁢c4−2⁢c8⁢x⁢x+4⁢c4⁢x625⁢c9−2⁢x1025⁢c9+&c. ut patebit substituendo in allatam Regulam, 1 pro m, 5 pro n, c5 pro {P, & c4⁢x−x5c5} pro Q. Potest {illeg}|e|tiam −x5 substitui pro P, & c4⁢x+c5−x5 pro Q, et tunc <1v> evadet ⑤c5+c4⁢x−x5‾=−x{ +c4⁢x+c55⁢x4+2⁢c8⁢x⁢x+4⁢c9⁢x+c1025⁢x9+&c}. Prior modus elig{illeg}|e|ndus est si x valde {parvum sit, posterior si valde} magnum.

Exampl: {sic} 3. Est N③y3−a⁢a⁢y‾{hoc estN×y3−a⁢a⁢y‾−13=N×}1y+a⁢a3⁢y3+2⁢a49⁢y5+7⁢a681⁢y7+&c. Nam P=y3. Q=−a⁢ay⁢y. m=−1. n=3. {A=Pmn=y3×−13} =y−1. hoc est 1y. B=mn⁢A⁢Q=−13×1y×−a⁢ay⁢y=a⁢a3⁢y3&c.

Exampl: {sic} 4. Radix cubica ex quadrato-quadrato ipsius d+e (hoc est d+e‾43 Est d43+4⁢e⁢d133+2⁢e⁢e9⁢d23−4⁢e381⁢d53+&c. Nam P=d. Q=ed. m=4. n=3. A=Pmn=d43 &c.

Eodem modo simplices etiam potestates eliciuntur. Ut si quadrato-cubus ipsius d+ehoc estd+e‾5, seud+e‾51 desideretur: erit juxta Regulam P=d. Q=ed. m=5 & n=1; adeoqꝫ A=Pmn=d5, B=mn⁢A⁢Q=5⁢d4⁢e, & sic C=10⁢d3⁢e⁢e, D=10⁢d⁢d⁢e3, E=5⁢d⁢e4, F=e5, & G=m−5⁢n6⁢n⁢F⁢Q=0. Hoc est d+e‾5=d5+5⁢d4⁢e+10⁢d3⁢e⁢e+10⁢d⁢d⁢e3+5⁢d⁢e4+e5.

Quinetiam Divisio, sive simplex sit, sive repetita, ꝑ eandem Regulam perficitur. Ut si 1d+e, hoc estd+e‾−1sived+e‾−11 in seriem simplicium terminorum resolvendum sit: erit juxta Regulam P=d. Q=ed. m=−1. n=1. & A=Pmn=D−11=d−1 seu 1d. B=mn⁢A⁢Q=−1×1d×ed =−ed⁢d, & sic C=e⁢ed3, D=−e3d4 &c Hoc est 1d+e=1d−ed⁢d+e⁢ed3−e3 d4+&c.

Sic et d+e‾−3 (hoc est unitas ter divisa ꝑ d+e vel semel per cubum ejus,) evadit 1d3−3⁢ed4+6⁢e⁢ed5−10⁢e3d6+&c.

Et N×d+e‾−13 hoc est N divisum ꝑ radicem cubicam ipsius d+e evadit N×1d13−e3⁢d43+2⁢e⁢e9⁢d73−14⁢e381⁢d108+&c

Et N×d+e‾−35 (hoc est N divisum per radicem quadrato-cubicam ex cubo ipsius d+e, sive N⑤d3+3⁢d⁢d⁢e+3⁢d⁢e⁢e+e3‾ evadit N×1d35−3⁢e5⁢d95+12⁢e⁢e25⁢d135−52⁢e3125⁢d185&c.

Per eandem Regulam Genesses Potestatum, Divisiones ꝑ potestates aut ꝑ quantitates radicales, et extractiones radicum altiorum in numeris etiam commodè instituuntur.

Extractiones Radicum affectarum in speciebus i{illeg}|m|itantur earum extractiones in numeris, sed methodus Vietæ et Out|g|htredi nostri huic negotio minus idonea est, quapropter aliam excogitare adactus sum cujus specimen exhibent sequentia Diagram̄ata ubi dextra columna prodit substituendo in mediâ columnâ valores ipsorum y, p, q, r &c in sinistra columnâ expressos. Prius Diagramma exhibet resolutionem hujus numeralis æquationis y3−2⁢y−5=0; Et hic in supremis numeris pars negativa Radicis subducta de parte affirmativa relinquit absolutam Radicem 2|09455148‾: et posterius Diagramma exhibet resolutionem hujus liter{ariæ} æquationis y3+a⁢x⁢y+a⁢a⁢y−x3−2⁢a3=0.

<2r>

_________________________._____________.__________________________________________________ +2,10000000−0,00544852 +2,09455148 _________________________._____________.__________________________________________________ 2+p=y y3 −2⁢y −5 +8+12⁢p+6⁢p⁢p+p3 −4−02⁢p −5 p3summap3 −1+10⁢p+6⁢p⁢p+p3 _________________________._____________.__________________________________________________ +0,1+q=p +p3 +6⁢p⁢p +10⁢p −1 +0,001+00,03⁢q+0,3⁢q⁢q+q3 +0,061+01,20⁢q+6,3⁢q⁢q +1,001+10,0⁢q −1 q3summaq3 +0,061+11,23⁢q+6,3⁢q⁢q+q3 _________________________._____________.__________________________________________________ −0,0054+r=q +q3 +6,3⁢q⁢q +11,23⁢q +0,061 −0,0000001+00,000⁢r+&cq3 +0,0001837−00,068q −0,0606420+11,23q +0,061 q3summaq3 −0,0005416+11,162⁢r _________________________._____________.__________________________________________________ −0,00004852+s=r ._____________. _ _

_ _________________________._____________.__________________________________________________ a−x4+x⁢x64⁢a+131⁢x3512⁢a⁢a+509⁢x416384⁢a3&c _________________________._____________.__________________________________________________ a+p=y y3 +a3+3⁢a⁢a⁢p+3⁢a⁢p⁢p+p3 +a⁢x⁢y +a⁢a⁢x+a⁢x⁢p +a⁢a⁢y +a3+a⁢a⁢p −x3 −x3 −2⁢a3 −2⁢a3 _________________________._____________.__________________________________________________ _________________________._____________.__________________________________________________ −14⁢x+q=p p3 −164⁢x3+316⁢x⁢x⁢q&c +3⁢a⁢p⁢p +316⁢a⁢x⁢x−32⁢a⁢x⁢q+3⁢a⁢q⁢q +a⁢x⁢p −14⁢a⁢x⁢x+a⁢x⁢q +4⁢a⁢a⁢p −a⁢x⁢x+4⁢a⁢a⁢q +a⁢a⁢x +a⁢a⁢x −x3 −x3 _________________________._____________.__________________________________________________ _________________________._____________.__________________________________________________ +x⁢x64⁢a+r=q 3⁢a⁢q⁢q +3⁢x44096⁢a&c +316⁢x⁢x⁢q +3⁢x41024⁢a&c −12⁢a⁢x⁢q −1128⁢x3−12⁢a⁢x⁢r +4⁢a⁢a⁢q +116⁢a⁢x⁢x+4⁢a⁢a⁢r −x3 −x3 −6564⁢a3 −6564⁢a3 −116⁢a⁢a⁢x −116⁢a⁢a⁢x _________________________._____________.__________________________________________________ _ 000+4⁢a⁢a−12⁢a⁢x+131128⁢x3−15⁢x44096⁢a+131⁢x3512⁢a⁢a+509⁢x416384⁢a3.000

In priori Diagram̄ate primus terminus valoris ipsorum p, q, r, in prima columnâ invenitur dividendo primum terminum sum̄æ proximè superioris ꝑ coefficientem secundi termini ejusdem sum̄æ \ut −1 per 10 aut 0,061 per 11,23 et mutando signum quoti./: et idem terminus eodem ferè modo invenitur in secundo diagrammate. Sed \Verùm/ hic præcipua difficultas est in inventione primi termini radicis: id quod methodo \um/ generali \em qua id/ perficitur, sed hoc \{anc}/ brevitatis gratia jam prætereo, ut et alia quædam quæ ad concinnandam operationem spectant. Neqꝫ \enim/ hic compendia tradere vacat, sed dicam tantum in genere quod radix cujusvis æquationis semel extracta pro regula resolvendi consimiles æquationes asservari potest possit; {illeg} quod|qꝫ| {illeg} ex pluribus ejusmodi regulis, r{illeg}|e|gulam generaliorem plerumqꝫ efformare liceat; \&/ quodqꝫ radices omnes, sive simplices sint sive affectæ, modis infinitis {illeg} extrahi {p}ossint, de quorum simplicioribus itaqꝫ semper consulendum {illeg} est.

<2v>

Quomodo ex æquationibus, {sic ad infinitas series reductis, ar}eæ & longitudines curvarum, cont{en}ta et sup{erficies solidorum, vel quorum}libet segmentorum figurarum quarumvis eoru{mqꝫ centra gravitatis deter}{illeg}|m|inan{illeg}|t|ur, & quomodo etiam Curvæ omnes Mechanicæ {ad ejusmodi æquation}es infinitarum serierum reduci possint, indeqꝫ Prob{lemata circa ill}as resolvi perinde ac si geometricæ essent, nimis longum foret describere. Sufficiat \cerit/ specimina quædam talium Problematum recensuisse: inqꝫ ijs brevitatis gratia literas A, B, C, D &c pro terminis seriei, sicut sub initio, nonnunquam usurpabo.

1. Si ex dato sinu recto vel sinu verso arcus desideretur: sit radius r & sinus rectus x eritqꝫ arcus =x+x36⁢r⁢r+3⁢x540⁢r4+5⁢x7112⁢r6+&c. hoc est =x+1×1×x⁢x2×3×r⁢r⁢A+3×3⁢x⁢x4×5⁢r⁢r⁢B+5×5⁢x⁢x6×7⁢r⁢r⁢C+7×7⁢x⁢x8×9⁢r⁢r⁢D+&c. Vel sit d diameter & x sinus versus, et erit arcus =d12⁢x12+x326⁢d12+3⁢x5240⁢d32+5⁢x72112⁢d52+&c hoc est =d⁢xin1+x6+3⁢x⁢x40⁢d+5⁢x3112⁢d⁢d+&c.

2. Si vicissim ex dato arcu desiderentur sinus: {illeg} sit radius r et arcus z, eritqꝫ sinus rectus {illeg} =z−z36⁢r⁢r+z5120⁢r4−z75040⁢r6+z936288⁢r8−&c, hoc est =z−z⁢z2×3⁢r⁢r⁢A−z⁢z4×5⁢r⁢r⁢B−z⁢z6×7⁢r⁢r⁢C−&c; Et sinus versus =z⁢z2⁢r−z424⁢r3 +z6720⁢r5−z84032⁢r7+&c, hoc est z⁢z1×2⁢r−z⁢z3×4⁢r⁢r⁢A−z⁢z5×6⁢r⁢r⁢B−z⁢z7×8⁢C.

3. Si arcus capiendus sit in ratione datâ ad alium arcum: esto \circuli/ diameter =d, Chorda arcûs dati =x, & arcus quæsitus ad arcum illum datum ut n ad 1; eritqꝫ arcûs quæsiti chorda =n⁢x+1−n⁢n2×3⁢d⁢d⁢x⁢x⁢A+9−n⁢n4×5⁢d⁢d⁢x⁢x⁢B+25−n⁢n6×7⁢d⁢d⁢x⁢x⁢C +36−n⁢n8×9⁢d⁢d⁢x⁢x⁢D+49−n⁢n10×11⁢d⁢d⁢x⁢x⁢E+&c. Ubi nota quod cùm \si/ n est numerus impar, series desinet esse infinita, & evadet eadem quæ prodit ꝑ vulgarem Algebram ad multiplicandum datum angulum ꝑ istum numerum n.

4. Si in axe alterutro AB ellipseos ADB (cujus Figure centrum C & axis alter DH) detur punctum aliquod E circa quod recta EG occurrens Ellipsi in G motu angulari feratur, & ex datâ area sectoris Ellipticæ BEG quæratur recta GF quæ à puncto G ad axem AB normaliter demittitur: esto BC=q, DC=r, EB=t, ac duplum areæ BEG=z; & erit GF=zt−q⁢z36⁢r⁢r⁢t4+10⁢q⁢q−q⁢q⁢t120⁢r4⁢t7⁢z5 −280⁢q3+504⁢q⁢q⁢t−225⁢q⁢t⁢t5040⁢r6⁢t10⁢z7+&c. Sic itaqꝫ Astronomicum illud Kepleri Problema resolvi potest.

5. In eâdem Ellipsi si statuatur CD=r, CBqCD=c, & CF=x, erit arcus Ellipticus DG=x+16⁢c⁢c⁢x3+110⁢r⁢c3⁢x5+114⁢r⁢r⁢c4⁢x7+118⁢r3⁢c5⁢x9+122⁢r4⁢c6⁢x11+&c −140⁢c4−128⁢r⁢c5− 124⁢r⁢r⁢c6−122⁢r3 ⁢c7 +1112⁢c6+148⁢r⁢c7+388⁢r⁢r⁢c8 −51152⁢c8−5352⁢r⁢c9 +72816⁢c10
Hic numerales coe{illeg}|f|ficientes supremorum terminorum 16.110.114&c sunt in musica progressione, & numerales coefficientes omnium inferiorum in unaquaqꝫ columna prodeunt multiplicando continuò <3r> Numeralem coefficientem supremi termini ꝑ terminos hujus progressionis 12⁢n−12.33⁢n−34.54⁢n−56.75⁢n−78.96⁢n−910.&c: ubi n significat numerum dimensionum ipsius c in denominatore istius supremi termini. E:g: ut terminorum infra 122⁢r4⁢c6, numerales coefficientes inveniantur, pono n=6, ducoqꝫ 122 (numeralem coefficientem ipsius 122⁢r4⁢c6) in12⁢n−12 hoc est in1; et prodit 122 numeralis coefficiens termini proximè inferior{is;} dein duco hunc 122in33⁢n−34 sive inn−34 hoc est in34 & prodit 388 numeralis coefficiens tertij termini in ista columna. Atqꝫ ita 388×54⁢n−56 facit 5352 num: coeff: q:ti termini & 5352× 75⁢n−78 facit 72816 numeralem coefficientem infimi termini. Idem in alijs ad infinitum usqꝫ columnis præsta{illeg}\ri/ potest, adeoqꝫ valor ipsius DG ꝑ hanc regulam pro lubitu produci.
Ad hæc si BF dicatur x, sitqꝫ r latus rectum Ellipseos & e=rAB; erit arcus Ellipticus
BG=r⁢xin 1+2−32⁢e} 3⁢r x −2 +3⁢e −58⁢e⁢e } 5⁢r⁢r x⁢x +4 −9⁢e +234⁢e⁢e −716⁢e3 } 7⁢r3 x3 −10 +30⁢e −1234⁢e⁢e +918⁢e3 −45128⁢e4 } 9⁢r4 x4 +&c.
Quare si ambitus totius Ellipseos desideretur: biseca CB in F, & quære arcum DG ꝑ prius Theorema & arcum GB ꝑ posterius.

6 Si vice versa ex dato arcu Elliptico DG quæratur sinus ejus CF, tum dicto CD=r, CBqCD=c, & arcu illo DG=z erit
CF=z−16⁢c⁢c⁢z3−110⁢r⁢c3⁢z5−114⁢r⁢r⁢c4⁢z7−&c. +13120⁢c4+71420⁢r⁢c5 −4935040⁢c6
Quæ autem de Ellipsi dicta sunt, omnia facilè accommodantur ad Hyperbolam: mutatis tantum signis ipsorum c & e ubi sunt \{ea}/ imparium dimentionum.

7. Præterea si sit CE Hyperbola cujus Figure Asymptoti AD, AF rectum angulum FAD constituant & ad AD erigantur utcunqꝫ perpendicula BC, DE occurrentia Hyperbolæ in C & E, & AB dicatur a, BC b, & area BCED z, erit BD=zb+z⁢z2⁢a⁢b⁢b+z36⁢a⁢a⁢b3+z424⁢a3⁢b4+z5120⁢a4⁢b5&c: ubi coefficientes denominatorum prodeunt multiplicando terminos hujus arithmeticæ progressionis, 1,2,3,4,5&c in se continuò. Et hinc ex Logarithmo dato potest numerus ei competens inveniri.

8. Esto VDE Quadratrix cujus vertex V, existente Figure A centro & AE semidiametro circuli ad quem aptatur, & angulo, VAE recto. Demissoqꝫ ad AE perpendiculo quovis DB & acta Quadratricis tangente DT occurrente axi ejus AV in T: dic AV=a, & AB=x, eritqꝫ <3v> BD=a−x⁢x3⁢a−x445⁢a3−2⁢x6945⁢a5−&c. Et VT=x⁢x3⁢a+x415⁢a3+2⁢x6189⁢a5+&c. Et area AVDB=a⁢x−x39⁢a−x5225⁢a3−2⁢x76615⁢a5−&c Et arcus VD=x+2⁢x327⁢a⁢a+14⁢x52025⁢a4+604⁢x7893025⁢a6+&c. Unde vicissim ex dato BD, vel VT, aut areâ AVDB arcuv{illeg}|e| VD, ꝑ resolutionem affectarum æquationum erui potest x seu AB.

9 Esto Deniqꝫ AEB sphæroides, revolutione Ellipseos AEB Figure circa axem AB genita, & recta planis quatuor, AB ꝑ axem transeunte, DC parallelo AB, CDE perpendiculariter bisecante axem, et FC parallelo CE: sitqꝫ recta CB=a. CE=c. CF=x. & FG=y; et sphæroideos segmentum CDFG, dictis quatuor planis compr{illeg}|e|hensum erit.
+2⁢c⁢x⁢y−x3⁢c⁢y3−x20⁢c3⁢y5−x56⁢c5⁢y7−5⁢x576⁢c7⁢y9−&c −c⁢x33⁢a⁢a−x318⁢c⁢a⁢a−x340⁢c3⁢a⁢a−5⁢x3336⁢c5⁢a⁢a−&c. −c⁢x520⁢a4−x540⁢c⁢a4−3⁢x5160⁢c3⁢a4−&c. −c⁢x756⁢a6−5⁢x7336⁢c⁢a6−&c −5⁢c⁢x9576⁢a7−&c. −&c.
Ubi numerales coefficientes supremorum terminorum 2,−1−3,−120,−156,−5576&c in infinitum producuntur multiplicando primum coefficientem 2 continuò ꝑ terminos hujus progressionis −1×1−2×3.1×34×5.3×56×7.5×78×9.7×910×11.&c. Et numerales coefficientes terminorum in unaquaqꝫ coluna descendentium in infinitum producuntur multiplicando continuò coefficientem supremi termini in prima columna per eandem progressionem, in secunda autem per terminos hujus 1×12×3.3×34×5.5×56×7.7×78×9.9×910×11&c; in tertia ꝑ terminos hujus 3×12×3.5×34×5.7×56×7. 9×78×9.&c, in quarta per terminos huius 5×12×3.7×34×5.9×56×7.&c, in quinta ꝑ terminos huius 7×12×3.9×34×5.11×56×7.&c Et sic in infinitum. Et eodem modo segmenta aliorum solidorum designari, & valores eorum aliquando commodè ꝑ series quasdem numerales in infinit{illeg}|um| produci possu{n}t.

Ex his videre est quantum fines Analyseos ꝑ hujusmodi infinitas æquationes ampliantur: quippe quæ earum beneficio, ad omnia, penè dixerim, problemata (si numeralia Diophanti et similia excipias) se{illeg}|s|e extendit Non tamen omninò universalis evadit, nisi ꝑ ulteriores quasdem methodos eliciendi series infinitas. Sunt enim quædam Problemata in quibus non liceat ad series infinitas ꝑ divisionem vel extractionem radicum simplicium affectarumve pervenire: sed quomodo in istis casibus procedendum sit jam non vacat dicere; ut neqꝫ alia quædam tradere quæ circa reductionem infinitarum serierum in finitas, ubi rei natura tulerit, excogitari. Nam parcius scribo, quod hæ speculationes diu mihi fastidio esse cœperunt, adeò ut ab ijsdem jam ꝑ quinqꝫ ferè annos abstinuerim. Unum tamen addam: quòd postquam Problema aliquod ad infinitam æquationem deducitur, possint indè variæ approximationes in usum Mechanicæ nullo ferè negotio formari, quæ ꝑ alias methodos quæsitæ, multo labore temporisqꝫ dispendio constare solent. Cujus rei Exemplo esse possunt Tractatus Hugenij aliorumqꝫ de Quadratu\râ/ circuli. Nam ut ex datâ arcûs chorda A, & dimidij arcûs chorda D arcum illum proxime assequarim, finge arcum illum esse Z, et circuli radium r; juxtaqꝫ superiora erit A (nempe duplum sinûs dimidij z) =z −z34×6⁢r⁢r+z54×4×120⁢r4−&c. <4r> Et B=12⁢z−z32×16×6⁢r⁢r+z52×16×16×120⁢r4−&c. Duc jam in B in numerum fictitium n & {a} producto aufer A, & residui secundum terminum (nempe −n⁢z32×16×6⁢r⁢r+z34×6⁢r⁢r, eo ut evanescat, pone =0, indeqꝫ emerget n=8, & erit 8⁢B−A=3⁢z∗−3⁢z564×120⁢r4+&c: hoc est 8⁢B−A3=z errore tantum existente z57680⁢r4−&c in excessu. Quod est {illeg} Theorema Hugenianū.

Insuper si in arcûs Bb sagittâ AD indefinitè productâ Figure quæratur punctum G à quo actæ rectæ GB, Gb abscindant tangentem Ee quamproximè æqualem arcui isti: esto circuli centrum C diameter AK=d, & sagitta AD=x et erit DB =d⁢x−x⁢x‾ =d12⁢x12−x322⁢d12−x528⁢d32−x7216⁢d52−&c. Et AE=AB=d12⁢x12+x326⁢d12+3⁢x5240⁢d32+5x72112⁢d52+&c. Et AE−DB.AD∷AE.AG. Quare AG=32⁢d−15⁢x−12⁢x⁢x175⁢d−vel+&c. Finge ergo AG=32⁢d−15⁢x, & vicissim erit DG32⁢d−65⁢x.DB∷DA.AE−DB. Quare AE−DB=2⁢x323⁢d12+x525⁢d32+23⁢x72300⁢d52+&c. Adde AB et prodit AE=d12⁢x12+ x326⁢d12+3⁢x5240⁢d32+17⁢x721200⁢d52+&c. Hoc aufer de valore ipsius AE supra habito et restabit error 16x72525⁢d52+vel−&c. Quare in AG cape AH quintam partem AD , & KG=HC; & actæ GBE, Gbe abscindent tangentem Ee quamproximè æqualem arcui Bab errore tantum existente 16x3525⁢d3⁢d⁢x+vel−&c; multo minore scilicet quam in Theoremate Hugenij. Quod si fiat 7⁢AK.3⁢AH∷DH.n, & capiatur KG=CH−n erit error adhuc multò minor.

Atqꝫ ita si circuli segmentum aliquod BAb ꝑ Mechanicam designandum esset: primò reducerem aream istam in infinitam seriem; puta hanc BbA= 43⁢d12⁢x32−2⁢x525⁢d12−x7214⁢d32−x9236⁢d52−&c; dein quærerem constructiones mechanicas quibus hanc seriem proximè assequerem; cujusmodi sunt hæc.

Age rectam AB, & erit segm: BbA=23⁢AB+BD‾×45⁢AD proximè, existente scilicet errore tantum x370⁢d⁢d⁢d⁢x+&c, in defectu: vel proximiùs er{illeg}|it| segmentum illud, (bisecto AD in F et acta recta BF,) =4⁢BF+AB15×4⁢AD, existente errore solum̄odo x3560⁢d⁢d⁢d⁢x+&c. qui semper minor est quàm 11500 totius segmenti, etiamsi segmentum illud ad usqꝫ semicirculum augeatur.

Sic et in Ellipsi BAb cujus vertex A, axis alteruter AK, et latus rectum AP, cape PG=12⁢AP+19⁢AK−21⁢AP10⁢AK×AP; in Hyperbola verò cape {illeg} PG=12⁢AP+19⁢AK+21⁢AP10⁢AK×AP: & acta recta GBE abscindet tangentem AE quamproximè æqualem arcui Elliptico vel Hyperbolico AB, dummodo ar{cus} ille non sit nimis magnus. Et pro area segmenti Hyperbolici BbA, in DP cape DM =3⁢ADq4⁢AK, & ad D & M erige perpendicula Dβ, MN occurrentia semicirculo super diametro AP descripto, eritqꝫ 4⁢AN+Aβ15×4⁢AD=BbA Figure proximè vel proximius \propius/ erit 21⁢AN+4⁢Aβ75×4⁢AD=BbA, si modoò capiatur DM=5⁢ADq7⁢AK.

© 2026 The Newton Project

Professor Rob Iliffe
Director, AHRC Newton Papers Project

Scott Mandelbrote,
Fellow & Perne librarian, Peterhouse, Cambridge

Faculty of History, George Street, Oxford, OX1 2RL - newtonproject@history.ox.ac.uk

Privacy Statement

  • University of Oxford
  • Arts and Humanities Research Council
  • JISC