1. A>
%
DISSERTATIO
GRADUALIS,
DE
INTERPOL ATIONF ASTRONOMICA,
Quam,
EX CONSENSU ÄMPLISS. FAC. PHILOSOPH.
IN ACADEMIA UPSALENSI,
1'r.iside
BENEDICTO FERNER,
Mathes. PROFESS. Carolicor. Reg. et Ord.
Astron. PROFESS. Yic. Upsal.
Acad. Scient. Stockh. MEMBRO,
IN AUDIT. GUST. D. XV. MARTII
AN NI MDCCLVIII.
H. A.M S.
PUBLICE VENTILANDAM SJSTIT
ALUMNUS REGIUS
THORBERNUS BERGMAN,
V. GOTHUS,
ADScniPTUS SOC. SCIENT. UPSALENSI ET ACsIDENUjE STOLKHOLMENSL
VFSAL/E, Excud.L. M. HÖJER, Reg. Acad. Typogr.
X
a
MONSIEUR
LE BARON
VOLTER REINHOLD STACKELBERG,
COLONEL de Regiment de Cavallerie
de la Noblefle,
CHEVALIER & COMMANDEUR de
F Ordre
de TFpée-
I es
moignerhontes
depuisque Vous
queavez
f aiMen F homieur dl voulu me
ette-
re aupres deMonfieur Votre
treseher fils,
neme permettent pas de
negliger
cetteoccafion
pourVous en marquer une
fotbk mals fincere
recon- noiffance. C efi en prenmtla liberte de Vous
prefmur ee petit ouvrage que
je Vous ßupp lie de
•régarder dl un oeilfavorable & comme une preuve
de la parfaite
foumijjion
& du profond refpect
évec lequel je fuis,
MONSIEUR,
Votre tresbumlte&ires oheijfantjerutern?
THORBERN BERGMAN.
/. M
J.
§. L
luamvis nodro tempore
adcura»
tiffimis Obfervatoria prasdita
fint indrumentis, multisque
prseterea modis pra&icaAdro-
nomia fublevata priorum fecu-
lorumomnem induftriamfupe-
ret, interim tarnen adhuc vel in maxime faventi-
bus circnmdantiis paucorurn fecundorum error vix, ac ne vix quidem evitari poted, qui etd in-
terdum parum noceat, interdum tamen enormia
generat vitia. Ut igitur Adronomi in exiguis quantitatibus dimetiendis occupati minuant, quan-
tum pofTunt, errorem, non immediate parvas hafce quantitates,
fed majores illas
continentesobfervant , & ex Iiis datis intermedias quasvis
eruunt.
Sint 711, p admodum exigna in coelo fpa- tia, feorum fumma, e error in obfervando inevi-
A 2 tabilis,
❖ ; 4 ( ❖
tabilis, ti hxcce fpatiola immediatis
obfervationi-
bus innotefcerent, conftat, illa futura viPpPey tt*e, pPte frf^je —
m^etn+efplte,
fed Ii obfervatur
fpatium/illud invenietur ffpe*
In aprico igitar eft, ii ex
dato f
einveniri
pos- funt in, n & p valoremcujusvis
a vero tantumnon aberraturum, quantum
PPPe valet,
namhic
error dividitur inter ?n> n & p, adeo ut errorum famma heic dt aequalis errori
cujusvis quantitatis
in priori cafu.
§. IL
Sint - - - p., ([} Ty
fy
ty TI - - "- - " Cly by Cy (ly €y f "
duae talesferies quantitatumquarumcumque,utcui-
vis fuperioris feriei termino p
refpondeat quidam
a in inferiore, ex fuperiore certa quadam lege genitus. Termini p,p, r
&c.
vocanturradices
Sc ay by c 8cc.functiones refpondentium radicum.
Inventio radicis datae fun&ioni & funftionis euivis datae radici refpondentis vocatur Interpola¬
tio, quae aflronomica
audit,
iiad folvenda proble-
mata aftronomica adhibetur. Huic fcopo Sum-
mus Newtonus in Princ. math. phil. nat. libr. III.
lem. V. dedit methodum inveniendae curvae para- bolicae per quaevis data pun&a
tranfeuntis,
ubi ra.dices pro abfciiiis & funftiones pro ordinatis
fu-
mit; fed Celeber. F. C. Majer in A£t. petr. tom.
II. p. »8o. viam Aftronomis longe aptiorem
in»
greffus eft, quam in
praefenti diflertatione brevF
ter explicare
ejusque adplicationem in folvendis
quX»
#>5(4
qroefHonibus aftronomicis oftendere animiis eft,
quod
facturus benignam C. L. mihi
expetocenfu-
ram.
§. III.
Ex di&is patet,
fummam difficuftatem do0xi-
nx interpolationis in eo confiftere ut inveftigetur
lex
generationis fun&ionum. Sit
xradix
quse- vis; g-,h, k,
- - - fi quantitåtesconftantes
ex fun&ionibus a, b, c - - - f derivandae* v nu¬merus terminorum, & lex generalis fecim-
dum quam qusevis
fun&io
afua radice
generatur g t hx f kx2- - - - nxv " in eo cardorefolu-
tionis vertitur, ut eruantur valöres coefficientium
g3 h --- n,
hifce
enim cognitis, cognitaquoque eil: lex generationis.
§- iv.
Ut determinentur merporati coefficientes (§.
III.) fupponamus primum paucos terminos in qua- libet ferie.
I;o fint p, q radices
a.} b fun&iones
& erit (§. III.) lex generationis g-f hx. Cum jam x indigitet quamvis radicem, ponamus pri-
mo x Hp eritqueg t hp ~ a, & deinde x~ q,
undtgfhq~ b. Ex hifce
duabus
sequationibus faci-r - __ aci —
bp
__b
— a .le eruitur g ——— & b , unde
Ü — P q — p
t •• , , ctq —
bp
b — alex generationis g f hx f x
q p q p
A3 _ a
o—
b)
X
« ) 6 ( -f _ r
❖
q—p
II:o Sint p3 q, r rad.
aj b, c £un£t.
eruuntur eodem modo valöres
fequentes
'
_aq—bp,
a(r—q)--l< (r—p)fc(q—p)
g— rr—n—ttt:—rm—r< PI
h~
1 -
g f
b
p't
(p-q)(r—p)(
a jr—q) —b (r—pj 'Ic
(q—p)
(p —q)(r
—p)(tf
—p)ü
.J.
(r — j)—b(r~P) fc (g—
Pi
q—P (r —q)
(r
—p)(q—p)
b i (•i(r—
q)—P(r—p)\c(q-p) (r—q)(r—p)(q—p)
a
(r—q)—b(r—p)-\c (q—p) (r—q)(r—p)(q—p)
){-<?- -P) -P)
& lex generationis
f hx
fkx*
c falx
-]Lb~
q-p} a ( r—q
b
(r—p
(x—P)(x— q){ \ a (r
L —
■\ c (q—p)i
)(r—tf) (<1-P(
^\ t
(^
P^) )
t'v) —
[
f c(q—p)\(q-p)(r—p)(r—q)
III:o Sint p, q, r, s rad.
b, c, d funO:.
Cl
ent
.# ) 7 ( &
,rf
a(r—q)
erit gÅ ~- Sé -
J7b(.r~P) (*-?)■(/-p)
] f c(q~p)(s—q\ls— p)t
l—
d(q—p)(r—p)(q—p}}
Plr
(q-p)(r-p){s-p)(r-q){s-r)
(s-q)'
f a (r—q) (s—r)(s
£— i
j —b{r—p){s—r) (i—p
'[ f r(..4_—p)(s—
q)(s—
p)f{—ä(r~q)(r—p)Cq—p i&iprfqr
(V—p)ir—p)(s—p)(r—q)(s—r)(s—
'
f
a(r—q)(s>~r)(s—q)~
—b(r—p}(s—r) C$~-py f
c{q-p)(s—q)(s—p)
— d(r— q)— (—
—j> —ff —r
(q—p)(r—~PHs—p)(r—q)(ks—r)
(s—q)f f a(r—q)(s—r)(s—q
j
—b (r—p) (s—r ) ( —p~)
•j f l—d(r~q){r—p){q-. c(q—pj(s—q)(s— q)
X
k
X
/
X
(q—p)(r—p)(s—p)(r~-q) (s—r)
(s—q)
ii // / f
& g \ hx
\ kx2 f /x3
ZZL
•k—y
——x
isu
— ibs
— sjib—dbi—
'(f—i) (b—s)
(b—a)(i—s) (i—x)
(i—b) 5 4'
(s—i) (b—i)(b—a)
(i—f) (i—a)
(i—b) p—
(s—i) (b—i)
(b—s) (i—f)
(i—s) (i—i)
o
£}
4 _et q
(s—i) (a—f)
(a—s) (i—f) (i—s)
(i—a) q—
is—f) (a—f)
(a—s) (b—i)
(b—s) (b—a)
v\A
(
S-f)(A~i)(A~s)(b~i)(b-s)(b--a)(i-l)(irS)(i-A)( i-b)
sabi
x
Xs—i)(b—s) (b—a)
(i—s) (i—a) (i—b)
9
^7
(s—f)(b—i) (b—a)
(i—f) (i—a)
(i—b) p—\
(s—i) (b—t)(b—s)
(i—i)(i—s)(i—b) o 4
(s—i) (1—1)
(i—s) (i—i)
(i—s) ( i—a) q—
(s—f) (1—1)
(t—s) (b—i) (b—s)
(b—a) 2g
•^nnj 9 'p 'o 4q 'v
•psj f 's 'a 'b 'i o.*ax ras
1
= ft
(a-s) (b-s)
(b-a) (i- s ) ( i- a) (i-b)
(a
— x) (b
— x)(i—x)
(b-A)(i—A)(i—b)p
—
(b—s)(i—s)(i
— b)f I
( a
— s){i—s)(i—a)
q—
(
a—s)(b
— s)(b—a)v
^
# ) 8 (
❖
x
# ) # V(
rf«
(r—(J-—^ ft—q)
(((t—sh—b
(r—p)
(s—p) (t—p) r)(t—r) (ts) k—kf( f c(q—p)(s—p)(t—p)(s—q)(t—
\—d(q—p)
{r—p) Ci—p)
(r—q) (t—q)(tt—s)Lf
e (q—p)( r—p)(tr—p) (r—q)(.r—q)(J
rs f ps f qs -j* rp fpq -{• rq
(q-p)(r-p)(s-pj{t-p)(r-q)(s-q){t-qj(s-r)(t-r)(t-s)
rf a(ir—q) Cr—q)
(t—q) (s—r)
(t—r) (—b(r—p) s—r)(t—r)(r—p) O'—p) C (t—s)
l—
/f( fc(iJ—p) (r—p)(t—p)(s q)(t—q)(t—s)
—d(q—p) Or~P) (f—P)( (t—s)
.fe Ol—P)
Or—p) (s—q)
(t—s)■—p — q — r — s
f a(r—q)
(s—q)
(t—q) (s—r)(t—r)
(t—s) ^—b(r—p)
(s—p)
(t—p)(s—r) (t—r) (t—s) fc (q—p)(s—p)(t—p) (s—q) (t—q)(t—s)-d (q—p)(r—p)(t—p)[r—q)(t—q)(t—s)
L f e (tp-p) (r—p) (s^p) (r—q)(s—q)(t—s)
J
X
7)1
X
(q-q)
(r-p)(s-p)(t-p){r~q)(j^)(t-q)(s-r)(far)(t~s)
ill ni il i m
Sc g f
hx j* kx2 f Ix
?f
mxA ~Z Lii H L
B
X
# 10 ( # )
f (s—q) (t—q) a(r—q)
s—r(t-r) (t—s)
—b (s—p)(r—p)
(t—p) (t—s) t{ ft(q-p)(t—p)(t—P)(t—q).(t-q)(t—s)
—d(q—p) (r—p)
(t—p) (r—q) (t—q) (t—s)
f«(q—p)(r—p) (s—p) (f—q)(s—q) v—*)
(x—p) (x—q) (x—r) {x—s)
V:o Sint py q-, r, .f, t, u rad.
a, by c, dy ßy f fun£b eritque
lex
generationisIV IV in ii i a1
g -j- hx
*[• k
x2f l
x3f
?n x4f
nxs iL
f
ci(r-q)(s-q)(t-q)(u-q)(s-r) (t-r)(u-r)(t-s)(u-s)(u-t)
— b(r-p)
(s-p)(t-p)(u-p)Cs~r) (t-r)(u-r)(t-s)(u-s)(u-t)
f
c(q-p) (^pW-p^(u-py(MXH)iu"4yt'S%u-s)(U't)
—d(q-p)(r-p)(t-p)(u-p)Cr-qXt-q)Cu-q)(t-r)(u-r)(u-t)
f
)fu-r)(u-s)
—f(q-p)(r-p)(s-p)(t-p)(r-q)(s-q)
(t-q)(s-r)(t-r) (t-s)
_(x-qX^%t-^%u-^)(^Xt-r)(u-r)(t-s)(u-s)(u-t)(r-p)(s-p)(t-p)(ii-pJ(q-f)
( —A, ut evitetur prolixa repetitio hujus
membri)
X (x-zrp) (x—q) (x—
r)
(x—s) (x—t)IV TJI
g~g — * (—pqrst)
IV in
b ZZ h — A (pqrt f pqst f pr st fpqrs f
qrst)
in ii
kil b — ^ (— Prt— pqr— pqs—prs —pqt—pst
— qst— qrs — qrt — vst)
II I
IZZl —*
(^fprfqt\rs\rt\st)
i
m ~ vi —A (—p — q — r —s— t)
nZZ— A.
COR. I. Qui adtentius praecedentia
confide-
rat facile videbit quamvis legem
generationis
con- ftare ex legeprsecedente &
novomembro, cujus
valör
generalis hunc in modum invenitur.
Sint py q-, r - - - - t, u
radices
Uy by c e,
f fun&iones
Sit A produ&um
differentiarum omnium radf
cum, excepta prima;
B
produ&um differentiarum omnium radicum*
excepta
fecunda;
C
produftum differentiarum omnium radicum,
excepta tertia;
&
ita porro pro numeroradicum.
SitF
produftum differentiarum omnium radicum,
excepta
ultima;
E
produ&um omnium differentiarum inter
x&
quamvis
radicem,
exceptaultima;
G produ&um
omnium diverfarum differentiarum
in Ay By C - - - F.
Hifce pofitis
formula novi membri haec eft:
— (Aci—Bb Cc - - -
rtFf).
G
Signum
pofidvum valet fi
numerusradicum eft
impar,
negativum
autemin cafu oppofito.
COR. IL Expreffiones generales pro
omnibus
B 2 coeffi-
^ ) 12 C #
coefficientibus legis generationis g f hx - - - -
lxv"3 f ?nxv~ 2 f nxVml fequenti modoeruuntur.
Sitß praecedentis legis terminus non du&us in x
h. e. refpondens r£ g in addufta.
y coefficiens t9xv~2 A
$ coefficiens tux1 3
-l
jnlege pracedente.
4 coefficiens x -
J
M Samma omnium radicum - - -
N Summa omnium produ&orum bi-
membrium ex omnibus radicibus -
excepta
ultima.
J^Summa omnium produ&orumv-2mem-
brium ex omnibus radicibus - - R Summa omniumprodu&orum v-/mem-
brium ex omnibus radicibus - - Et ita porro pro numero radicum.
Praeterea denominationes in preecedente corol- lario factse in hoc quoque valent.
Hinc fequentes exfurgunt formulse
aA — bB f cC - - - ffi: fF
n - ± 1—
E
Signum f valet fi numerus radicum impar, alias
vero fignum — .
aA— bB Jr cC - - A fF
m_y± i—
i—(~U\
E
, _ äA— bB f cC - . ±fF
/ — <? -t— —N
E
❖ ) »J c #
aA-bB f cC - - ±fF
b = f ^ —
r£ fi)
- -
g=/3^t
rt/F—«K)
In
penultima formula eft pofitivum fi
numerus radicum eft par, alias negativum, contrarium au-tem valet de R in ultima, quod quoque ex ipfts fignis patet.
Schol. Formular coefficientium adlatse pro ca- ftbus
particularibus
Iongeevadunt fimpliciores,
quarum
nonnullas
praximaxime infervientes ad-
danir
I. Si o, /, 2 radices
o, b, c fun&iones
crit g H o hu 2b —
kn\c —b
IL Si Oy iy 2y 3 radices
Oy by Cy d fun&iones
erit g~o
h ~3b —\c f
k ZZ2C — — \d lZZ\b — \c f *d
III. Si Oy ty 2, 3y 4 radices
Oy by Cy dy e fun&iones
B 3 erit
# ) 14 C 2jc
crit g — o
b H 4-b — 3C f #<* — i*
*=-¥>f
¥<r-f f u*/ II P — 2C f — \e mH—zb
{
lc — $df
f4?IV. Si 0, /, 2,^,4,1 radices
o, £j c, d, *, / fun&iones
erit g H o
h ~Z1 iob — f xfd — £<?
f
\fk~- \qb f ♦«*-
vd f
f^-/*/
i n W* - f #<* -
Ü' f A/
7/zH—-T^b f Wc— d
f
h\e —hf
71 H JjC "I* ~~ 24
i*
iV. Si o, qy r radices
Oj b, c fun&iones
crit g H o
brz — cqz
b H
qr (r —q)
cq —br qr(r—q)
VI. Si Oj qj Yj s radices
Oj b, c, d fun&iones
^ „—
€Cls (x—tf) —brs (x—y) —(r—q)
72rx (r—g)
(x—r) (#—x)
cq — br
k — - — — l
(q fr)
qr (r-q)
❖ ) *f c ❖
h n -—
Ar
—kq
£ ZZ o
§.
v.
Datis quibusdam
radicibus & funStionibus
re- fpondentibus, qua nonmuUum diflant, invenire
fimctionem
cujusvis data radicis intermedia, & ra-
dieem cujusvis data
funclionis intermedia.
I. Sit x radix cujus
fun&io quseritur, eritque
haecg f
hx
- -f nxv'1 ( §. III. Cum jam den-
tur quaedam
radices & fun&iones refpondentes ex
formula numero datorum conveniente eruuntur coefficientes g, h
--»(§. IV.);
^ quoqueda-
tur (perhyp.), ergo
valoribtis fubflitutis funftio
qusefita
determinatus
II. Sed ex data fun&ione g f hx - -
f nxv"1
non invenitur radix x, nifi
refolvendo aequatio-
nem, quae
fun&ionem exprimit, quod vel per
Algebramvulgarem fit, vel
perGeometriam fub-
limiorem eft tentandum.
§- VI.
Hifce expofitis
de interpolatione in
genere,jam fupereft
ütufum,
quemhxc do&rina Aftro-
nomise praeftat
paucis
tangamus.Potuit quidem
hicce calculus adhiberi ad
enodandas plures
qux-ftiones aftronomicäs, quam in
fequentibus fit, fed
in
prüfend hsecce fumciant,
cum exadlatis fatis
conftare crediderim & ubi &
quomodo hxc
me-thodfus utilis effe poffiu
Per
# ) «d { #
Per locumfideris datum in
fequentibus
intelli-go, non tantum fitum ejus refpe&u
Eclipticse
&iEquatoris cognitum, Ted etjam temporis momem tum, quo in eo
fuit.
§. VII.
Datis locis quibusdam vicinis Planeta vel Co-
meta invenire intermediapro tempore quovis inter- fnedio.
Sumantur tempora locis datis convenientia pro radicibus, & loca pro fun&ionibus. Sit x tempus cui locus refpondens requiritur, erit hic
g f hx - - nxv"ly qui facile innotefcit per dato-
rum fubftitutionem ( §. V. )_.
Exemplum.
Ponamus Cometam quendam menfe Majo ob- fervatum. ehe, diftantem a ftella quadam fixa
O III
9' 58- 33 die S'-z media nofte
11. 13. 40 - 6
12. 32. 2 7
13- 53- 52 - 8
qussritur ejus locus die 6:a & hora 6:a poft mediam
no&em. Sumtis temporibus pro radicibus, & lo¬
cis pro fun£tionibus, erit p ~: y, #~ 6, r ZZ 7,
O / // o tu
s __ 8 ? xZZ6&, a~ 9- 58- 33i bzzu. 13. 40,
Olli o 4 H
c ZZ 12. 32. 2, d ZZ 13. 53. 52. Hifce valoribus fubfticutis in formula g f hx f kx 1 f lx% prodit
flin&io tempori x refpondens. Sed calculus tali modo
& ) n ( #
modo inflitutus admodum prolixus & toedii plenus
evadit, quo igitur hoc
incommodum
evitetur,io-
co radicum 5, 6, 7, 8> 6T| ponantur aliae éodem
modo progredientes 0, /, 2, 7, &
loco fiirt-
£tionis cujusvis differentia eam inter & prknam,
Hoc modo pzz o, (]Zi, r ~~ 2y s H f>
O I II fl o
XZZI2T, «no, £ ~i 1. 15. 7 11 4507, c .1: 2.
/ // II o / // //
33. 29 H 9209*, d ~ 2. 55. 19 ~ 10519. & per fbrmülam fecundam in §:i IV:ae Scholio datam in*
venitur / II— 597^, £n 1891 > h — 3213L £—o>
// o III
unde g f /a.v f 2 f /.v * ZZ 5745 H 1. 35. 45,
quod additum primo loco obfervato
dat
quaefitumo / //
II 11. 30. 48. -
Schol. Per addu&um problema velocitas
angularis'
pro parvo quovis tempore inveniri poteft. Nam fit T parvum tempus pro quo re-quiritur velocitas angularis.
Interpolando
proditlocus planet^ ad initium & finem
ftujus
temporis,quorum differentia eil: fpatium tempore T percur-
uim, quod proinde oftendit velocitatem angula-
rem huic convenientem.
In exemplo modo adlato locus Cometx media
o / //
noQie die 6:a Maji erat 11. 13. 40 & hora fexta
o 1 II / 11
fubfequente 11. 30. 48,
differentia
17. 8 monftratvelocitatem pro lex
horis.
C §.
VIIL
♦ ) i8 C #
§. VIII.
Iisdein datis cic in prxcedentepciragrcipho, in*
venire tempus, gz/ofidus in quovis puncto interme¬
dia verfetur. Sit # tempus quaefitum, locus ei
conveniens erit g *\ hx -- nxvm1, ex quo valöre,
numero datorum convenienter determinato, qua>
ritur x (§„ V,).
COR. L Hinc ex datis quibusdam locis paulo
ante &poft oppofitionem vel conjunctionem Planetas invenituripfümmo?nentum.NamTumtistemporibus,
locis datiscongruentibus, proradicibus (quodinfe- quentibusfemperfit,nifiexpreffe aliud moneatur)ßc
locis profunfHonibus, asquatiopro momento oppo-
o
fitionis Xefi:^ f
h
x- -f nxvm1 ~ 180, & pro mo¬mento conjunfifeionis g f bx-- f nxv~l ZZ 0,
COR. IL Momientum elongationis maxim#
Planetas inferioris ex datis quibusdam
elongattyni-
bus- ante & poft, quas pro fun&ionibus adfunvan-
tur, per hanc asquationem eruitur hdx - - f n. v-2xv"2 dx ~ 0.
COR. III. Ex datis quibusdam altitudinibus
meridianis folis paulo ante & poft folftitium, in-
notefcit ipfum Solßitii momentum x. Nam funi-
tis diebus-obfervationum pro radicibus, & altitu¬
dinibus meridianis pro
fun&ionibus
r formula ge¬neralis pro omnibus altitudinibus folis eft g ,f hx
^kx 2 - - f nxv"Iy Sed altitudo folftitialis efi: vel
maxima vel minima, ergo fi
formula propoftta
diffe
$ ) i? { $
differentietur & elementum nihilo sequetur, prod-
it asquatio pro obtinendo momento folftitii refol*.
venda xv~2 - - f —-^rx f —-— ~~ o.
72.v- / 71.v-1
Haec a Cel. Majero primum inventa metho- dus cum reliquis notis collata & facilitate & exa£H- tudine fefe commendat.
COR. IV. Exdatis quibusdam Iocis folis asqui-
no&io utrinque vicinis, datoque primo pun&o figni Arietisdeterminatur momentum cequinodtii.
Kam fumtis diftantiis ab interfe&ione- iEquatoris
& Eclipticae pro fun&ionibus , adparet formulam generalem pro diftantia quasfita nihilo elfe sequan-
dam, & ex hac aequatione x eruendum.
COR. V. Ex datis locis quibusdam adparentL
bus centrorum folis & lunce paulo ante, poft &
inträ ipfam
ecliphn folarem
momentnminitii, finisy
maximacque obfcuratioms innotefcit. Nam (it O dia¬meter adparens folis, d lunas, qure ad momentum
quodlibet calculo erui poffunt, Si diftantias adpa-
rentes centrorum folis & lunae fumantur pro fun- ctionibus, eritg f hx - - f nxVm/ ~D f d aequa- tio pro initio.& fme, & hdx - - - fn.v i. xv*2 dx
ZZ. o pro momento maximas obfcurationis.
§. IX.
Datis locis quibusdam nodis lätitudmi ma-
ximx utrinque vicinis, invenire lova no-åorum zf mclinationem Orbits. L Sumtis diftantiis a nodo pro
fun£tioniDus,_gf
hx - - \nxy'1 ~ o efl valörC 2 pro
$ ) i© ( $
pro loco nodi, ex quo, inveftigato per
fubftb
tutionem prodit quaefitum ( §. VII.).
II. Sumtis latitudinibus pro fun&ionibus, per üuxionem fbrmulae functionum invenitur x, ex- quo dato inveftigatur per §. VII. latitudo maxima
b. e. inclinatio orbitae.
§. X.
Ex åatis quibusåam velocitatibus angiilctrwm
invenire locum'& tempus cuivis alii intermedia re-
fpondentia. Sumantur velocitates angulares pro functionibus, & (i locus quaeritur loea pro radici- bus, tempora vero, fi indagandum tempus. De-
inde per §. V. eruitur quaeßtum.
COR. Ex datis quibusdam velocitatibus Pla¬
netas, maximas & minimae utrinque vicinis invefti- gari
poteft perihelium, aphelium
& momentet tran- jitus. Nam invento tempore veloeitati maximaevel minimae congruente, locus huic conveniens erui poteft (§.VI1.) i. e. perihelium vel aphelium.
Idem hoc qtioque modo ohtinetur: quaeritur pro- f>e lineam apßdum utrinque locus aequali velocita-
ti refpondens, locus interhos medius eft perihe¬
lium vel aphelium.
§.XI.
Datis quibusdam altitudinibus ante poft fi- deristranfitwn per meriäianum, mowentum tranfi-
lus & altitudinem meridianam invenire. Sumtis altitudinibus obfervatis, fed pro parallaxi Se
refra-
eftione corre&is, pro
funöionibus,
cumaltitudo
meridpma ßt maxima exaequatione hdx f2k
xdr
-- -
fn.
) 21 ( ^
• -
fv-i.xVm2 dx ~o
inveniri potefl:
xf.
momen*tum tranfitus, quo cognito per
folam fubftitutio-
nem innotefcit fun&io refpondens
h»
e.altitudo
meridiana.
ScboL Hoc problema magno
ufui efTe potefl
Lo quando
nubecula qusedam ipfam lideris culmi-
nationem celat, quam tarnen
cognofcere
interdume re eft, quaeque prseterea
dimeilius immediate
obfervatur, (altem extra Obfervatoria. Infervit igitur Geographo
alicubi
nonultra diem
commo- ranti, fi unice peroblervatam akitudinem folis
me- ridianam latitudinem loci eruere polTet. 2:0 Quinad corrigendum
meridiem adhiberi poflit nulTus
dubito,nam nec calculi,quos tentavi, aliudinnuunt,
nec altitudo meridiana fuppofita maxima ullam pa- titur variationen! per augmentum vel deeremen-
tum declinationis, faltem ad quandam folis diftan-
tiam ab asquino&iis, qux omnia
forte alio
tempo¬re uberius exponere licebit.
§. XII.
Ut ipfe
calculus facilior evadat fequentia im-
primis funt obfervanda:REGULA I:a. Si radices in ratione arithmeti-
ca progrediuntur & prima
nihilo eft major,
earum loco alia ponaturferiesin eade?n ratione progredient^fed qua a
ziphra incipit.
e. g.Si diebus
8> 9, 10& 11 Martii, eadem hora qualibet die, qusedam
faftse funt obfervationes,quarum tempora pro radi-
cibus habenda funt, earum loco progreffio o, 1, 2, 3 poni
debet, modo
notetur oindicare
8:am Martii, x nonam,& itaporro.REG/
$ ) 22 (
REG. II. Si radicum differenti#in#qiiales
funt
&primus termmus nihilo major, ali# radicesfub- Jlituend#, quarum prima efl ziphra, quarum
differenti# äquales funt differentiis rej*ectarum. e.
g, pro 7, 9, io, 13 üibflitui debent o, 2, 3, 6.
REG. III. Pro qaavis funciione fubflituenda eß differentia ea?n inter primam. Sit a funCtio rima, b fecunda Sc c tertia, loco a, by c poni de-
ent a — a ~o, a — b, a —c refpeCtive, quod
tarnen ultimo adtendendum, (i enimquxritur fun-
Ctio y, ultimus valör hane non dat fed a — y.
REG. IV. Si magnus numerusterminorum in' calculum introduci debet, loco functionum interpo¬
land#
Junt
earum differenti# ( differenti#prim#),vel etjdm differenti# harum differentiarum ( diffe¬
renti#
fecund#).
Notandum eil:, hoc modo in- veniri poffe non tantum differentiam datas radici convenientem 3 fed etjam maximam Sc minimampoffibilem.
§. XIII.
Quod ad numerum terminorum interpolando-
rum adtinet, obfervandum efl:, tres radices tres-
que funCtiones fufficere, (i radices Sc fun&iones continue crefcant vel decrefcant
uniformiter,
(ive crefcant radices decrefcentibusfunCtionibus,
five hifce crefcentibus decrefcant radices; fed ad mini¬mum quatuor radices totidernquefunCtiones requi-
ri, (i radicum functionumve differentiaeadmodum funt inasquales, vel etjam modo adfirmativte, mo¬
do negativas h. e. modo crefcentes, modo decre-
icentes. Tandem
$ > 2J ( $
Tandem verba Cel. Abbatis D.i De la Gallie
jv addere liceat: "Tout
cecalcul, inquit,
n'edqu"une approximation: par le moien de certaines di-cc menfions prifes d'efpace en efpace,onconclud les^c intermediaires, en fuppofant que leurs inegalités Ä
fuivent condamment une certaine loi; ce que n"
approche de la judefle qu'autant que ces elpaces"
font plus ferrés, & ces dimenlions moins irregu-a
lieremcnt inegales, ou que la loi qu'on a trouvée"
approche le plus de la veritable loi de ces ine- "
galités". Vid. Ejus Adr. p. 73. « XIV.
Problemata addu&a exemplis ex Cometa nu- per obfervato petitis illudrare animus fuit, fed
cum dellas quasdam, quibuscum in Obferva-
torio Upfalenii ed collatus, adhuc non fuerit
occaho fatis exa£te determinandi, & prasterea ii\
nodrarum lupplementum hucusque deh-
derentur obiervationes exterorum, hifce
fubfidere cogor.
TANTUM.
MONSIEUR.
eß Vous, ä qui mon tres eher Pere, ?n* a con-
fiéj quand je trieloignois de chez lui, la premiere
fois:
La fendrejje, vif les grands foins, lesquels Vous avez Jdtisfait ä cette confian-cey fonty qu il riy a pas un moment pour moi plus agreahle, que celui de V occafion que Vous me
fourniffésy de Vous en montrer ma reconnoiffaii-
ce. Comment donc pourrois je me negliger quand
Vous
aüez donner aupublic
une ßfeavan-
te dijfertationy Jans
Vous
marquer majoie en Vousen felicitaM. Vous n'avez pas befoin de mes lou-
anges, & je ne pourrois en ajouter aueunes d
Celles que Vous font deja accordées par des juges plus competens, mais / ai le plaifir de prendre
pant d
rhonneur
qui Vous attendhf
d Vous fou-halter d' un coetir fincere toutes fortes de
profpe-
rites. Je
fuis
ctvec éfiime,MONSIEUR,
Vblretreshumble&Jres obeifantferviteurt ADOLPH STACKEI.fiERG.