( ^m ) 
Ati Extraft ofi a letter from the Excelleni: R^mm FmdftmSlk* 
C^^non ofLUge and Counfellor to his Elcdorai H'igli- 
misofCoiUn, written to the PubliOier in order to be comrau- 
mcatedto the^ iyoW^ry • concerning his fhort and caiic 
thad @f ck'/imng Tangents ts all Geometrical Curves without any la- 
bour of ealculatioa ; Here inferted in the fame language, in 
which k was written. 
MEthodf^m meam ducendarum ad Curvas qHaflihet Geometri<^ 
cos T mgenmm mim ad Te^ & Virarum DoEiiJfmorHm 
K. Societatis €enfur>3i fubmltto, Brevis mihi vifaeft acfacilis, quiffe 
quam fHer Ay^fArftdos docerifojfit^ & qn^ abfqne ullo ealenli Ubore 
ad omnes emnim lineas exundatnr : Mah tamen alt Is talem videri qnkm 
mihiy CHm in rebpu noflris Ccccutire flerf^^e [Qleamm, 
W^g.i.Data fit igitur qnMet Cnrva D^mnjm fmBa-omnia r^feran» 
turad RtEtam qmmlibet datam E A B per ReEtamDAS five E A B fit 
diameter fet^ alia qmlibet ^ five etiam alidi fimul lifte<e datafinty qua^vet. 
qftarum potefiatts z/Eqmtionemingrediantur farnm id refert. 
In^quatione A- 
ndytka , facilioris 
explicatianis caufay 
D A ferpetHo dicatnr 
VyBA,y. EB vera t 
& alids qmptitates 
data y Confonan- - , n ■ ' _ 
tibus exfrimantur, ^ •A B C 
Tum ftipfmatHr duUa D C, tangens cmvam in Z>, & occurrens EE.^' 
prodnibA^^ fiopH4 fit^ in pnnEio C ; & CA perpetuh qnoque dicatnr a.^ 
Ad inveniendam A Cvel a, kac erit Regula Generaiis ^ 
T. Reje^iis ab aquatione partibpu^ in quibns y vel v non invmttir y 
fiatuamuT ab uno latere omnes in quibm efi y, & ab altero ilia in qnibm 
habetPir VyCHm ftii^ [ignis \ vel . Hoc^ dextruwi iHfid^. finiBrum 
latm, facilitatls caufAy. vocabimm^ 
2.. Im latere dextroy prczfigatur fingulls partibns exponens potefi^is 
qMam'in illis obtimt v \ JeHy quod idem efi, in ilium dncanttir partes, 
3. Fiat idem in latere finifirOy pr^epone^dQ fcil. micuique illim parti 
Exponentem pneftatis qmm in iUa habet y, Sed & hoc ampUj^ : 1^- 
nHm^4nfingftlis partibm vertatur in 2l, 
Ajo, iy£quationem fic reformatam modmn oftendere dHcend<& Tan^ 
gtntis adpmiipim D datum. Cpim enim eo dato^ pariter dat£ fint y 
V, & catera qmmt^iW., qm Cdnfanantibas exprimmtHr Z -mn pO'^ 
ferit ign&r aru 
Si 
