66 



than those found by Dr. Brinkley, they appear to be equally inde- 

 pendent of accidental error. The author, however, is not inclined 

 to refer the cause of the differences to parallax, for they are sensibly 

 increased by direct comparison with an opposite star, as with Capella, 

 in which the maximum of parallax is nearly as great as in 

 a Aquilee ; and it is very unlikely that the parallax of one star should 

 exceed *5", and that of the other be an insensible quantity. More- 

 over, all these stars pass the meridian about the time of the winter 

 solstice at their maximum of parallax ; and in proportion as stars 

 do not possess this property, both the Astronomer Royal and Dr. 

 Brinkley either find a much smaller discordance, or none at all ; the 

 author accordingly is inclined to look for some explanation of the 

 difficulties in this peculiar circumstance. 



Tables are annexed to this paper, showing the method of com- 

 puting the equation, or index error, applicable to the north polar 

 distances. 



Appendix to Mr. Pond's Paper on Parallax. Read March 13, 1817. 

 {Phil. Trans. 1817, p. 173.] 



Being induced last autumn to suspect that the discordance in 

 favour of parallax, before met with, might arise from variation of 

 temperature, the author endeavoured last winter to keep the interior 

 and exterior of the Observatory of the same temperature, which the 

 mildness of the season easily enabled him to do. From the 1st of 

 July 1816 to March 1817, the index error of the instrument suffered 

 no variation ; and therefore the objections urged by Dr. Brinkley 

 were done away. Under these circumstances the observations of 

 a Lyrse, y Draconis, a Cygni, and a Aquilae, showed no indication of 

 periodical variation. Whether the fixed instruments lately erected 

 for this investigation will confirm the above result remains to be 

 determined. 



An Account of some Fossil Remains of the Rhinoceros, discovered by 

 Mr. Whitby, in a Cavern inclosed in the Lime-stone Rock, from 

 which he is forming the Break-water at Plymouth. By Sir Everard 

 Home, Bart. V.P.R.S. Read February 27,1817. [Phil. Trans. 

 1817, p. 176.] 



Having been requested by Sir Joseph Banks carefully to preserve 

 such organic remains as might be found in the quarries whence the 

 supplies of limestone for the break- water at Plymouth are drawn, 

 Mr. Whitby, who has the superintendance of the undertaking, 

 transmitted, in November 1816, a box of fossil bones, which form 

 the subject of the present communication. 



According to Mr. Whitby's report, they were found in a cavern 

 of the solid limestone rock, fifteen feet wide, forty-five long, and 

 twelve deep. It was filled with clay, and the bones lay about three 

 feet above the bottom. This cavern is about seventy feet below the 



