48 CELESTIAL MECHANICS: LEUSCHNER 



Elements S 20 are based upon 17 normal places made from 999 ob- 

 servations in a and 992 observations in 8 in the years 1898-1899, and 

 are derived from Elements R brought forward with the perturbations 

 of Venus, Earth, Mars, Saturn and Jupiter for 20-day intervals. 



Elements T 21 U 22 V 23 W 24 X 25 Y 26 are improvements of preceding 

 elements, as are Elements Z 27 AA 27 AB 27 AC 28 AD 29 and AE 30 . 

 Elements AE are Elements AC with special perturbations for 20-day 

 intervals for the period 1901, March 20, to 1903, June 8.0 applied. 

 These perturbations were computed by Wedemeyer, those of Venus, 

 Earth, Mars, Jupiter and Saturn being considered. 



Elements AF were found only in the B. J. for 1907. They are 

 probably Elements AE with the epoch changed and perturbations ap- 

 plied. Dziewulski has published "Sekulare Marsstorungen in der 

 Bewegung des Eros.," Bull, de PAcad. des Science de Cracovie 1905. 

 Not available here. Some mistakes are corrected in A. N. vol. 175, 

 p. 171. In A. N. vol. 175, p. 17, Merfield gives the secular perturba- 

 tion of Eros due to all major planets. Gauss' method by Hill. 

 Elements from Hill's memoir, Ast. Papers of the Amer. Ephm. Vol. IV 

 and Elements W. The secular perturbations by Jupiter, the Earth and 

 Venus are the largest. 



Elements AG are by G. Witt. 31 They are based upon observations 

 from 1893 to 1903, the perturbations of Venus, Earth, Mars, Jupiter 

 and Saturn being included. The perturbations were calculated by the 

 method of variation of constants. For Mars, Jupiter and Saturn the 

 perturbations were calculated for 20-day intervals and for Venus and 

 the Earth at 10-day intervals. With these elements he calculates the 

 perturbations from 1903 to the beginning of 1908, and includes these 

 in an ephemeris for 1905 for dates from July 17 to August 22 

 (B. J. 1907, p. 476.). 



Elements AH 32 AI 33 AJ 34 are preceding elements with change of 

 osculation. Elements AI are also found in the Connaissance des 

 Temps for 1915, but with the equinox changed in 1920.0, Greenwich 

 M. T. 



In an article "Beitrage zur Theorie der Bewegung des Planeten 433 

 Eros," E. Noteboom 35 uses Elements AL to compute the general 

 perturbations of Mercury, Uranus, and Nepture. A recurring run 

 in the residuals is not due to these planets. 



Noteboom then uses the twenty normal places of Witt 36 (which lie 

 between dates 1893 October 31 and 1907 October 8) and forms four 

 more normal places, one in 1910, one in 1912, and two in 1914. He 

 then gets Elements AM out of a least square solution by a correc- 

 tion of Elements AL. He gives the mass of Earth and Moon as 

 1/328370102 and 7r=8".799. 



No authority is available for Elements AK. 87 



