Book contents
- Frontmatter
- Contents
- PREFACE
- MEMOIR
- TREATISE
- Chapter I The occasion, excellence, and utility of the Observation
- Chapter II Account of the Observation
- Chapter III What others observed, or might have observed, of this Conjunction
- Chapter IV It is proved that the spot observed in the Sun's disc was really Venus
- Chapter V The Examination of the apparent Longitude and Latitude of Venus from the Sun
- Chapter VI The alteration of the apparent into the true situation of Venus
- Chapter VII An Inquiry into the Time and Place of the true Conjunction of Venus and the Sun
- Chapter VIII The Demonstration of the Node of Venus
- Chapter IX The beginning, middle, and end of the Transit are shewn
- Chapter X An Examination of the Calculations of Astronomers respecting the foregoing
- Chapter XI The Calculation of Copernicus
- Chapter XII The Calculation of Lansberg
- Chapter XIII The Calculation of Longomontanus
- Chapter XIV The Calculation of Kepler
- Chapter XV Correction of the Motions according to Rudolphi
- Chapter XVI On the Diameter of Venus
- Chapter XVII On the Diameters of the rest of the Planets, of the Proportion of the Celestial Spheres, and of the Parallax of the Sun
- Plate section
Chapter XVI - On the Diameter of Venus
Published online by Cambridge University Press: 05 August 2011
- Frontmatter
- Contents
- PREFACE
- MEMOIR
- TREATISE
- Chapter I The occasion, excellence, and utility of the Observation
- Chapter II Account of the Observation
- Chapter III What others observed, or might have observed, of this Conjunction
- Chapter IV It is proved that the spot observed in the Sun's disc was really Venus
- Chapter V The Examination of the apparent Longitude and Latitude of Venus from the Sun
- Chapter VI The alteration of the apparent into the true situation of Venus
- Chapter VII An Inquiry into the Time and Place of the true Conjunction of Venus and the Sun
- Chapter VIII The Demonstration of the Node of Venus
- Chapter IX The beginning, middle, and end of the Transit are shewn
- Chapter X An Examination of the Calculations of Astronomers respecting the foregoing
- Chapter XI The Calculation of Copernicus
- Chapter XII The Calculation of Lansberg
- Chapter XIII The Calculation of Longomontanus
- Chapter XIV The Calculation of Kepler
- Chapter XV Correction of the Motions according to Rudolphi
- Chapter XVI On the Diameter of Venus
- Chapter XVII On the Diameters of the rest of the Planets, of the Proportion of the Celestial Spheres, and of the Parallax of the Sun
- Plate section
Summary
Congratulate us, Gassendi, on clearing from suspicion your observation of Mercury, and let astronomers cease to wonder at the surprising smallness of the least of the planets, now they find that the one which seemed the largest and brightest scarcely exceeds it. Mercury may well bear his loss since Venus sustains a greater.
I observed the diameter of Venus (Chap. I.) to be 1′ 12″, the Sun being 30′; therefore the latter being 31′ 30″, the true diameter of the former is 1′ 16″. My friend Mr. Crabtree's observation agrees with this calculation: I am sure she did not appear greater; if there is any error, it is in an excess. There is no reason why any one should doubt the truth of the observation; unless indeed he is unacquainted with the telescope, or influenced by the knavery of the Peripatetics, or suspects our honesty; and I all not stay to argue either with those who have not seen this instrument or who mistrust its fidelity, for it is vain to contend with ignorance and self-will. Permit me to remind any who may suspect our good faith, how easy it would be to investigate the subject for themselves, and how little it would serve our purpose to distort truth by falsehood.
Let us then examine the opinions of others, in order that it may appear with what degree of accuracy astronomers have hitherto estimated the magnitudes of the stars.
- Type
- Chapter
- Information
- Memoir of the Life and Labors of the Rev. Jeremiah HorroxTo Which is Appended a Translation of his Celebrated Discourse Upon the Transit of Venus Across the Sun, pp. 187 - 201Publisher: Cambridge University PressPrint publication year: 2010