368 Mr. J. Taylor's Lectures on Mdalhirgy. 



we may assume January 20 as the correct argument without 

 any regard to the fractional part of" the day; and the calcula- 

 tion will stand as follows: 



For Right Ascension. 

 /3 Leonis = +1.6675 —9.44.36 —0.0146 +S.9583 

 January 20 = +9.4138 -0.8563 -0.9722 +1.2426 



+ 1.0813 +0.2999 +0.9868 +0.2009 

 For Declination. 



/3 Leonis = -1.3003 -8.9420 +9.5962 -9.4272 



Jamiary 20 = +9.4138 —0.8563 -0.9722 +1.2426 



--0-7141 +9.7983 —0.5684 —0.6698 

 The sum of the natural numbers, corresponding to these 

 logarithms, will give for the correction in right ascension 

 + 25",345; and for the correction in declination — 12",926. 



I trust tliis brief explanation of the tables will be sufficient 

 to enable the English astronomer to make use of them : I am 

 very sure there are no other tables whereby he can obtain the 

 same results with so much ease and expedition, and with so 

 little chance of error. It would be a gi-eat acquisition if the 

 constants were given for a greater nnmher of stars : in this case 

 the tables would supersede all others which have been com- 

 puted for such occasional references. 

 I am, gentlemen, 



Your obedient servant, 



Gray's Inn, May 15, 18.23. Francis Baily. 



LXXVI. Sketch of a Course of Lectures on Metallurgy ; deli- 

 vered at the London Institidion, February 1823. By John 

 Taylor, Esq. Treasurer of the Geological Society. 



[Continued from p. 291.] 



Lecture II. 



TT has been shown that the metals readily combine with a 

 -^ variety of substances, and that in this state of combination 

 they lose more or less of their metallic characters. 



In their natural state they are most usually thus combined, 

 and the substances in union with them are called mineralizers. 

 These consist of certain simple substances, some acids, water, 

 and even some metals. 



Under these heads may be enumerated as commonly occur- 

 ring in natural combination with the metals, 



Oxygen 



