[21.] CHRISTIANI HUGENII, Const. F. AD C. V. FRAN. XAVERIUM AINSCOM. S. I. EPISTOLA. Cl. Viro D°. XAVERIO AINSCOM CHRISTIANUS HUGENIUS S. D.

[22.] CHRISTIANI HUGENII, Const. F. DE CIRCULI MAGNITUDINE INVENTA. ACCEDUNT EJUSDEM Problematum quorundam illuſtrium Conſtructiones.

[23.] PRÆFATIO.

[24.] CHRISTIANI HUGENII, Const. f. DE CIRCULI MAGNITUDINE INVENTA. Theorema I. Propositio I.

[25.] Theor. II. Prop. II.

[26.] Theor. III. Prop. III.

[27.] Theor. IV. Prop. IV.

[28.] Theor. V. Prop. V.

[29.] Theor. VI. Prop. VI.

[30.] Theor. VII. Prop. VII.

[31.] Theor. VIII. Prop. VIII.

[32.] Theor. IX. Prop. IX.

[33.] Problema I. Prop. X. Peripheriæ ad diametrum rationem invenire quamlibet veræ propinquam.

[34.] Problema II. Prop. XI.

[35.] Aliter.

[36.] Aliter.

[37.] Problbma III. Prop. XII. Dato arcui cuicunque rectam æqualem ſumere.

[38.] Theor. X. Prop. XIII.

[39.] Lemma.

[40.] Theor. XI. Prop. XIV.

[41.] Theor. XII. Prop. XV.

[42.] Theor. XIII. Prop. XVI.

[43.] Theorema XIV. Propos. XVII.

[44.] Theor. XV. Propos. XVIII.

[45.] Theor. XVI. Propos. XIX.

[46.] Problema IV. Propos. XX.

[47.] Christiani Hugenii C. F. ILLVSTRIVM QVORVNDAM PROBLEMATVM CONSTRVCTIONES. Probl. I. Datam ſphæram plano ſecare, ut portiones inter ſe rationem habeant datam.

[48.] LEMMA.

[49.] Probl. II. Cubum invenire dati cubi duplum.

[50.] Probl. III. Datis duabus rectis duas medias propor-tionales invenire.