ASTRONOMICAL INSTRUMENTS. 



ASTRONOMICAL INSTRUMENTS. 



Plate 

 XIX. Fig. 



7. Precefllon of the Equinoxes 

 7.* Protthaphasrefis 



8. Quadrant, Horodiaical 



9- 

 10. 

 1 1. 

 12. 

 »3- 



of Altitude 

 Reduftion to the Ecliptic 

 Refraftion, Ailroiiomical 

 Retrogradation of Planets 

 of the Sun 

 14 — 16. Ring of Saturn 

 XX. Fig- ' — 3- Satellites of Jupiter 



4. Configuration 



5. Sphere, Armillary 



{For this fgure, fee AJhonomy, Plate lH-fg- hO 



6. Sphere, Ptolemaic 



7. Copernican 

 8 — 13. Stars 



14. Syftem, Ptolemaic 



Pythagorean and Copernican 

 Egyptian 

 Tychonic 

 Syflem, Solar 



Times of the Planets 

 Velocities of Planets 

 Afcending Nodes 



XXI. Fig. 5—7. Trigon 



8 — II. Venus 

 12. Year 

 13 — 22. Whirling Table 



XXII. Fig. Projeftion on the Plane of the Ecliptic 



of the Parabolic Orbits of 72 Comets 

 {This Plate is publijhed without any number. ) 

 I. Northern Hemifphere 



II. Southern Hemifphere 



Conftellations, Plate I. Orion 



Plate II. Urfa Major 

 Urfa Minor 



ASTRONOMICAL INSTRUMENTS. 



XXI. Fig. 



15- 



16. 



17- 

 I. 



2. 

 3- 

 4- 



I. Fig. 



II. 



III. 



IV, 



Fig, 

 Fig, 

 Fig. 



Allrolabe 



Davis's Quadrant, or Back Staff 



Crofs Staff, or Fore Staff 



Quadrant 



Nofturnal or Star Dial 



Newton's Quadrant 



Elton's Quadrant 

 I — 3. Mayer's Circle 

 4 — 9. Borda's Circle 

 I, 2, Englifh Reflefting Circle, by 



Troughton 

 I. Graduated Circle, with two Verniers 

 2 — 4- three Verniers 



V. 

 VI. 



VII. 



VIIL 



IX. 



X. 



XI. 



5' 



Fig. 



Fig. 



Mendoza's Circle 



Ramfden's Aftronomical Circle 



Borda's Repeating Circle, without re- 

 fleftion 



Troughton's Repeating Circle, 



General View of the Inftrument. 

 . View, with the Circle, Index, &c. de- 

 tached 



Circle, by the Rev. F. Wollaftou 



Portable Circle, by Troughton 



Troughton's Mural Circle 



Short's Portable Equatorial Inftrument 



Ramfden's Ditto 



Dollond's Ditto 



Pl.ATJ 



XI. 

 XII. 



Fig. 

 Fig. 



XIII. Fig. 



XIV. 



XV. 



XVI. 



XVII. Fig. 



XVIII, Fig. 



XIX. 

 XX. 



XXL 



Fig. 

 Fig. 

 Fig. 



Fayrer's Equatorial Inftrument 

 Nairne's Portable Equatorial Inftrument 

 Ramfden's Refraftion Apparatus 

 Dollond's Ditto 



4. Objedl Glafs Micrometer 

 Graham's Equatorial Seftor 

 Refraftion 



Smeaton's Micrometer 



Refraftion 



Equatorial Stand of a Telefcope, by 



Smeaton 

 Troughton's Univerfal Equatorial In- 

 ftrument 

 Shuckburgh's Equatorial Inftrument 

 Troughton's Equatorial Inftrument at 



Armagh 

 2. Siflbn's Equatorial Seftor 

 Cote's Equal Altitude Inftrument 



5. Earl of Hay's Equal Altitude In- 

 ftrument 



Divifion of Graham's Quadrant 



Bird's Ditto 

 Due de Chaulne's Dividing 

 Mr. Cavendifh's Ditto 

 Quinquefettions by Mr. Cavendifh 



1—3- 



XXII 

 XXIII 



Fig- 

 Fig. 



Troughton's Method of graduat- 

 ing a Circle 

 4 — 6. Troughton's Method of graduat- 

 ing a Circle 



1. Graduation 



2. by Clavius 



3. 4. by Mafcheroni 

 5. Bifeftion of an Arc 

 I — 4. Smeaton's Rotative Roof 



5, 6. Pearfon's Rotative Roof 



1. Hadley's Octant 



2. Cole's Quadrant 



3. Gunter's Ditto 



4. Graham's Mural Ditto 



5. Ramfden's Portable Ditto 



6. Troughton's Portable Ditto 

 XXIV. Fig. I — 7. Telefcope, Dollond's Experiments 



on Achromatic ObjeiSl: Glaftes 

 {Thefe Jigures are on P/a/f XXVIII. to "whiclt 

 the references ought to have been made. ) 



I — II. Theory of the Refrafting Tele- 

 fcope and Compound Microfcope 

 I — 8. Theory of Refradling Telefcopes, 



&c. 

 I — II. Theory of the Telefcope with re- 



fpeft to Aberrations, &c. 

 I — 5. Theory of Reflefting Telefcopes 

 I — 15. Principles of Achromatic Tele- 

 fcopes 

 XXIX. Fig. 1—5. Refrading Telefcope 



6 — 8. Five-feet Achromatic RefraAor 

 9. Pearl Dynameter 

 10, II. Jones's Ditto 

 12 — 15. Dollond's Dynameter 

 XXX. Fig. 1—3. Refleding Telefcopes 



4. Brewfter's Patent Telefcope 

 5 — 7. Scale of Minutes 

 8. Smeaton's Support 

 XXXI. Dr. Herfchel's Forty.feet Refleaing 



Telefcope 



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