AIDS OF THE NEWTONIAN PERIOD. 485 



Tycho Brahe's, containing the places of about 1000 stars, determined 

 very roughly with the naked eye. On the occasion of a project of 

 rinding the longitude, which was offered to Charles II., in 1674, Flam- 

 steed represented that the method was quite useless, in consequence, 

 among other things, of the inaccuracy of Tycho's places of the stars. 

 Flamsteed's letters being shown King Charles, he was startled at the 

 assertion of the fixed stars' places being false in the Catalogue, and 

 said, with some vehemence, " He must have them anew observed, ex- 

 amined, and corrected for the use of his seamen." This was the im- 

 mediate occasion of building Greenwich Observatory, and placing 

 Flamsteed there as an observer. Flamsteed's Historia Celestis con- 

 tained above 3000 stars, observed with telescopic sights. It has re- 

 cently been republished with important improvements by Mr. Baily. 

 See Baily's Flamsteed, p. 38. 



The French Histoire Celeste was published in 1801 by Lalande, 

 containing 50,000 stars, simply as observed by himself and other 

 French astronomers. The reduction of the observations contained in 

 this Catalogue to the mean places at the beginning: of the year 1800 

 may be effected by means of Tables published by Schumacher for that 

 purpose in 1825. 



In 1807, Piazzi's Catalogue of 6748 stars, founded on Maskelyne's 

 Catalogue of 1700, was published; afterwards extended to 7646 stars 

 in 1814. This is considered as the greatest work undertaken by any 

 modern astronomer ; the observations being well made, reduced, and 

 compared with those of former astronomers. Piazzi's Catalogue is 

 the standard and accurate Catalogue, as the Histoire Celeste is the 

 standard approximate Catalogue for small stars. But the new planets 

 were discovered mostly by a comparison of the heavens with Bode's 

 (Berlin) Catalogue. 



I may mention other Catalogues of Stars which have recently been 

 published. Pond's Catalogue contains 1112 Northern stars; John- 

 son's, 606; Wrottesley's, 1318 (in Bight Ascension only); Airy's First 

 Cambridge Catalogue, 726 ; his Greenwich Catalogue, 1439. Pear- 

 son's has 520 zodiacal stars; Groombridge's, 4243 circumpolar stars 

 as far as 50 degrees of North Polar distance; Santini's, a zone 18 de- 

 grees North of the equator. Besides these, Mr. Taylor has published, 

 by order of the Madras government, a Catalogue of 11,000 stars ob- 

 served by him at Madras ; and Rumker, who observed in the Obser- 

 vatory established by Sir Thomas Brisbane at Paramatta (in Australia), 

 has commenced a Catalogue which is to contain 12,000. Mr. Baily 



