The sidereal messenger of Galileo Galilei : and a part of the preface to Kepler's Dioptrics containing the original account of Galileo's astronomical discoveries (1880)
Galilei, Galileo, 1564-1642, Kepler, Johannes, 1571-1630, Carlos, Edward Stafford · London : Rivingtons · leaf 34
es by the size of then . ^ aperture of Q the telescope. For the sake of being more easily understood, Iwill suppose a tube A B c d/ Let E be the eye of theobserver; then, when there are no lenses in thetube rays from the eye to the object f g would bedrawn in the straight lines E c F, E d g, but… … The line c h in Galileos figure represents the small pencil of raysfrom H which, after refraction through the telescope, reach the eye e.The enlarged figure shows that if op be the radius of the apertureemployed, the point H of the object would be just outside the field ofview. The method, however,…
Astronomy
Internet Archive · Wellesley College Library · Public Domain Mark 1.0. Free to use for anything.
![An illustration from [Electric engineering.] (1902)](https://img.insideoutlibrary.com/img/200/ia-electricengineer04inte-228-91.webp)
