CAPUT VIII.

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4. Eft autem pro quavis differentia Ax“ab abfciffae x = Ba fuper-ficies rotanda AS in (2) major fuperficie rotunda coni truncati Porsop,et fimul minor fumma fuperficiei rotundae coni truncati PQqp, et fupcr-ficiei planae annuli radiorum rb, Qb in (3).

5. Superficies rotunda coni truncati Porsop, fumta ratione i:w ra-dii ad femiperipherram, eft w(2y+Av)Por—7r(2y + Ay)\/"Ay 2 Ax 2 ).

6. Superficies vero rotunda coni truncati PQqp eft x(2y + Ay+ rQ)PQ; et superficies plana annuli radiorum rb, Qb eft 7r(2y-f aAy+ Q r) Q r.

7. Quamobrem, ffy^(Ay 2 -f-A x 2 ) exprimatur per (469. §.), et rQ,PQ in (5) (6) determinentur ut mq,Mq in (462. §.), obtinebimus ex

( 5 ) (6) (4) pro certis coefficientibus k, 1 , m,-K, L, M, etc. fequentes

•xpreffiones*

A S A x /(ey 2 + ex 2 ) -f k A x* + 1 A x 3 -f- m A x 4 + ete.

A S A xV(s‘y 2 -f ex 2 ) -f- K A' x z + L A x > -f M A x 4 + etc.

Per (kZi. §.} eft itaque sSt= 27 ry/'(gy 2 +e x 2 , t=: 2 v y s/z (469. §.)Exponens differentialis funftionis S aequalis fuperficiei rotundae fegmeniiP B p, cujus integratio dabit fuperficiem 8.

Dd 3

CAPUT