ADDRESS. xi 



Thirdly. Observations, delineations, and Catalogues of the Nebulae. 



Fourthly. Observations of the minor planets. 



Fifthly. Cometary observations. 



Sixthly. Observations of the solar spots, and other phenomena on the 

 Sun's disc. 



Seventhly. Occultations of stars by the Moon, eclipses of the heavenly 

 bodies, and other occasional extra-meridional observations. 



And first as to cataloguing and mapping the smaller stars. This means, 

 as you know, the accurate determination by astronomical observation of the 

 places of those objects, as referred to certain assumed fixed points in the 

 heavens. The first Star Catalogue worthy to be so called, is that which goes 

 by the name of Flamsteed's, or the British Catalogue. It contains above 

 3000 stars, and is the produce of the labours of the first Astronomer Royal 

 of Greenwich, labours prosecuted under circumstances of great difficulty, 

 and the results of which were not given to the world in a complete form till 

 many years had elapsed from the time the observations were made, which 

 was during the latter half of the seventeenth century. About the middle 

 of the eighteenth century, the celebrated Dr. Bradley, who also filled the post 

 of Astronomer Royal, observed an almost equally extensive Catalogue 

 of Stars, and the beginning of the nineteenth century gave birth to that of 

 Piazzi of Palermo. These three are the most celebrated of what mav be 

 now termed the ancient Catalogues. About the year 1830 the attention of 

 modern astronomers was more particularly directed to the expediency of re- 

 observing the stars in these three Catalogues, a task which was much faci- 

 litated by the publication of a very valuable work of the Astronomical 

 Society, which rendered the calculations of the observations to be made com- 

 paratively easy, and accordingly observations were commenced and com- 

 pleted in several public and private Observatories, from which some curious 

 results were deduced, as e.g., sundry stars were found to be missing, and 

 others to have what is called proper motion. And now a word as to the 

 utility of this course of observation. It is well observed by Sir John 

 Herschel, " that the stars are the landmarks of the Universe; every well-deter- 

 mined star is a point of departure which can never deceive the astronomer, 

 geographer, navigator, or surveyor." We must have these fixed points in 

 order to refer to them all the observations of the wandering heavenly bodies, 

 the planets and the comets. By these fixed marks we determine the situation 

 of places on the earth's surface, and of ships on the ocean. When the places of 

 the stars have been registered, celestial charts are constructed ; and by com- 

 paring these with the heavens, we at once discover whether any new body 

 be present in the particular locality under observation : and thus have most 

 of the fifty-seven small or minor planets between Mars and Jupiter been 

 discovered. The observations, however, of these smaller stars, and the re- 

 gistry of their places in Catalogues, and the comparisons of the results ob- 

 tained at different and distant periods, have revealed another extraordinary 



