96 Astronomical and Nautical Collections. 



sun's mean horizontal parallax exceeds 8"-7, we have the following 

 equation, 



D = 606"- 122 - 3-030 P. 

 Making similar calculations for all the places, where the begin- 

 ning and end of the transit were observed, the following equations 

 are obtained : — 



Otaheite . . . . D = 606"-122 - 3-030 P 

 California . . . D = 606 '430 — 1*180 P 

 Hudson's Bay . D = 606 -560 + 0-915 P 

 Wardhus . . . . D = 605 -150 + 2-985 P 



Kola D = 606 -109 + 3-035 P 



Resolving these equations by the method of minimum squares, 

 to obtain the most probable values of D and P, D will be found to 

 be 606M28, and P + 0"-0988, making the sun's mean horizontal 

 parallax 8"-7988, or 8"-8. 



The other results, usually deduced from transits, such as the 

 times of nearest approach and ecliptical conjunction, the difference 

 of longitude of the various places, Venus's latitude at the conjunc- 

 tion, the distance from the node, and the duration of the transit, 

 'ndependent of parallax, may now be determined in a manner which 

 it is unnecessary here to explain. 



On comparing this method with those of La Lande, Maskelyne, 

 De Lambre, and Biot, it appears that in the former the final result 

 is not (as in the latter) deduced from quantities, such as Venus's 

 nearest distance, chord described during the transit, latitude, and 

 elongation, which cannot be known with accuracy, until the paral- 

 lax be determined. 



ii Remarks on the Discordances observed between the Lunar Ob- 

 servations at Greenwich and Paris. By Thomas Hen- 

 derson, Esq. 



Annexed is a state of the discordances between the solar and 

 lunar observations at Greenwich and Paris, in the years 1800-9, 

 mentioned in Astronomical and Nautical Collections, No. XXI. 

 Art. II. 



