Dico animo nostro primum simulacra meandi
Accidere, atque animum pulsare.
[3] The satellites of Jupiter are here called “the Cosmian Stars” in honour of Cosmo de’ Medici, but elsewhere Galileo calls them “the Medicean Stars.” Kepler sometimes calls them “the Medicean Stars,” but more often “satellites.”
[4] Galileo says, “per sex denas fere terrestres diametros a nobis remotum” by mistake for semi-diametros, and the same mistake occurs in p. 11.
[5] The words used by Galileo for “telescope” are perspicillum, specillum instrumentum, organum, and occhiale (Ital.). Kepler uses also oculare tubus, arundo dioptrica. The word “telescopium” is used by Gassendi, 1647.
[6] “Vix per duas Telluris diametros,” by mistake for “semi-diametros.”
The line C H in Galileo’s figure represents the small pencil of rays from H which, after refraction through the telescope, reach the eye E. The enlarged figure shows that if O P be the radius of the aperture employed, the point H of the object would be just outside the field of view. The method, however, is at best only a very rough one, as the boundary of the field of view in this telescope is unavoidably indistinct.
[8] Specimens of frosted or crackled Venetian glass are to be seen in the Slade Collection, British Museum, and fully justify Galileo’s comparison.