192 



Miscellanies. 



ticularly the latter. Mr. Rumker's letter not having given the final 

 results deducible from his equations of condition, the committee ap- 

 pended a letter from Mr. Sears C. Walker, in which he deduces from 

 Mr. Rumker's equations, the following corrections of the solar and 

 lunar elements given in the Nautical Almanac. 



d (0 + {|D)= - 2". 279 = correction of sum of semidiameters. 

 d (0 - (2D)= - 1".750= " difference of semidiameters. 

 <Z j3 1= _ 6".736 = " moon's latitude. 

 (Zir =+ 1".516= " moon's parallax. 

 d \ = - 2".276 = " moon's longitude. 

 These corrections being referred to the moon's orbit and its secon- 

 daries, give, after Bessel's notation (Astr. Nachr- 320) 

 { = - 2". 934 = cor. moon's place in true orbit. 

 {=-7".198= " on secondary to do. 



Mr. Peters, (Astr. Nachr. 326) without the American observations, 



had obtained 



J = - 3".650. 

 ^= -5"A72. 



Mr. Walker having previously reduced the American observations 

 with Peters's co-ordinates and corrections, furnishes a comparison of 

 the longitudes from Greenwich, derived by different computers from 

 this eclipse. 



Washington, (Capitol,) 



Haverford School, Delaware Co., Pa. 

 Germantown, C. Wister's private Observatory, - 

 Philadelphia, (State House,) . . - - 

 West Hills, (Coast Survey,) - . - . 

 Southwick, Mass., A. Holcomb's p. Obs. 

 Providence, Brown University, ... 



Dorchester, Mass., Wm. C. Bond's p. Obs. 



Walker from 

 Rumker's 

 equations. 



h. m. s. 

 5 8 13.83 



1 16..53 

 40.61 

 38.89 

 4 53 41.11 



J4 51 12.89 

 not reduced. 



Mr. Walker finds from the resolution of Rumker's equations of con- 

 dition, + t'''.516 for the correction of Burkhardt's constant of the 

 moon's equatorial parallax. In the Memoirs of the Astronomical So- 

 ciety, Vol. X, Mr. Henderson gives + 1".5 as the value of this correc- 

 tion, derived from Plana's Theorie de la Lune, and + r'.3 as the val- 

 ue of the same, derived from a discussion of all the meridian obser- 

 vations of the moon made in 1832 and 1833, with the mural circles at 

 Greenwich, Cambridge, and the Cape of Good Hope. This correc- 

 tion had hitherto been derived chiefly from theory and meridian ob- 

 servations. It is seldom that an eclipse or occultation has been so 

 extensively observed as to furnish a determination of this element. 

 In the present instance, the results by the three independent methods, 

 present a close agreement. 



Dr. Chapman, one of the Vice Presidents of the Society, stated that 

 he had received a letter from the Prince of Musignano, informing him 



