A decorative headpiece spans the top of the page. It consists of three horizontal rows of repeating floral stamps. The patterns resemble stylized fleur-de-lis or acanthus leaves, creating a dense, ornate border.

MATHEMATICAL

DICTIONARY.

That is, a list of all the words and principal subjects contained in this second volume.

Aben Nedin, an Arab, 275 Possibly a reference to Ibn al-Nadim, the 10th-century bibliographer, or another Arabic source used by Mersenne.
Definition of action, 567
Inscription of a circle, 80
Inscription of a triangle, 80, and of a triangulated figure, 81
Shading and shadow, 543
Comparisons of equals and unequals, 3
Functions of the equator, 26
Laws of equilibriums and balancing bodies, 439
Equilibrium on inclined planes, 445
What the equinoctial is, 249, 259, 260, and 261 The equinoctial is the great circle of the celestial sphere in the same plane as the Earth's equator.
Inhabitants of the equinoctial, 246, and 247
An equinoctial degree of 20 leagues, 260
Properties of equally weighing bodies, from 142 to 148
Proportion of equal weight, 453
Air denser than ether, 529
Agent and patient, defined, 567 In physics and philosophy, these terms describe the body that acts and the body that is acted upon.
White, black, green, red, blue, 486
Almucantars, or circles of progressions, 266 term: Almicantarath (Almucantars) are circles on the celestial sphere parallel to the horizon, used to measure the altitude of stars.
Height of a figure, 18
Amphiscii and Amphiumbrae, 261, and 271 term: Amphiscii refers to people living in the tropics whose shadows fall both north and south at different times of the year.
Elements of anaclastics, 589 Anaclastics is the study of refracted light.
Analogy, 14
Ordered and perturbed analogy, 14

Ten analogies, 35
The reasoning of refracted vision, 149
The Analysis of Viète, 330 François Viète (1540–1603) was a French mathematician who introduced modern algebraic notation.
Book 3 of the Analytics, number 372
Doctrine of angular sections, 389, through 392
Homogeneous angles, with matching sides, 66
Angles at the center and at the circumference, 79
Measurement of an angle, 181
Sine of an angle, 234. Proportionals, 232
Problematic contemplation of a solid angle, preface point viii.
Compared spherical angles, 205
Value of angles, 142
Laws of angles, 66
Properties original: "passiones", referring here to the geometric attributes or behaviors of angles in a plane, 68
Equality of angles in spherical geometry, 211
Divisions and properties of angles, 182
Angle in a segment, 8
Solid angle, 41
Angle of contact, 78
Angle in a section, 79
Angle in a semicircle, 80
Plane angle, 1, and 66
Angle of inclination, 190
Obtuse and acute angle, 1, and 67
What a spherical angle is, 204. Threefold.
Refracted angle, and angle of refraction, 515; of incidence, 514
A greater angle of inclination has a greater angle of refraction, 585