m 



ASTRONOMICAL PAPERS. 



167 



The next thing to be found Is OVE, or CVN, the angle 

 of the vifible way, which is got as follows. Let ? y e (Pli^te 

 IIL Fig. y,) be the inclination of the orbit of 2 with the 



Let e ^ be o's horary motion, with 



eclipticzr 3^ 23'. 20 



the menftrual equation, as from Mayer^s tables— 143", 53 

 and ? y the horary motion of $ asfeen from ©taken from 

 Halky's tablesr=238^334. Then, by trigonometry, the 



r^ 



??e ? will be found 



I 71"- 30' 



35"'^ 



the complement of 



which 9 e A, Is the angle of the vifiblc wayzzrS^- 



'^5 



r ^ 



9 



/ 



The fide 9 e Is the horary motion 9 a 9 as {ccn from the 

 Sun— 95'',4i8; which encreafedinthe ratio of? 's diftance 

 fromG, to her diftance from ©.gives her horary motioa In 



the vifible way— 239', 891- 



the meridional angle CVD, 



.1 



8 





54 



21 



fi 



But we had before ZVP, or DVL— 49^55 ^ ."i^i^ 

 And we have now got the angb 

 of the vifible way, CVN, 



j=8.29.25 



-=58.24. 58 



> 



Subt, their fumfrom CVD, and we have LVN,^24. 29. 23^ 



Wherefore, in the right-angled triangle LNV (which 

 being fmall may be refolved as a plain triangle) having 



found one angle LVN and the hypothenule LV, we get 

 the remaining fides, viz. 



lo"' 592 



VN the parallax in longitudc^^^ 



LN the parallax in latitude— 4. 8245. 



Now the parallax of longitude VN contributes to accele- 

 rate the contad; of Venus and the Sun, by Its whole length ; 

 but the parallax of latitude LN contributes to .accelerate the 

 fame by a fpace different from its whole length. 



There are feveral ways of explaining this matter, and 

 of converting the fpace LN Into a proportionable part for 

 acceleration. The following method, given by Mr. Rlt 

 tenhoufcy is that which we made ufe of, aad is as plain an 

 ftriaiy mathematical as any. 



44 



Let 



* This angle, in the NiU'rlton account ol' the tr^inHt, 'was called ^^. iS'. 'xf. ih;tt is near 

 l' Icis. ; tlic fjdo Q [5 bclui? coniimtcd iVom Hiilley's tables, not huvhij; M.i/cr'j* MbK^s at that 

 time. 



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